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1// SPDX-License-Identifier: GPL-2.0-or-later
2// SPI init/core code
3//
4// Copyright (C) 2005 David Brownell
5// Copyright (C) 2008 Secret Lab Technologies Ltd.
6
7#include <linux/acpi.h>
8#include <linux/cache.h>
9#include <linux/clk/clk-conf.h>
10#include <linux/delay.h>
11#include <linux/device.h>
12#include <linux/dmaengine.h>
13#include <linux/dma-mapping.h>
14#include <linux/export.h>
15#include <linux/gpio/consumer.h>
16#include <linux/highmem.h>
17#include <linux/idr.h>
18#include <linux/init.h>
19#include <linux/ioport.h>
20#include <linux/kernel.h>
21#include <linux/kthread.h>
22#include <linux/mod_devicetable.h>
23#include <linux/mutex.h>
24#include <linux/of_device.h>
25#include <linux/of_irq.h>
26#include <linux/percpu.h>
27#include <linux/platform_data/x86/apple.h>
28#include <linux/pm_domain.h>
29#include <linux/pm_runtime.h>
30#include <linux/property.h>
31#include <linux/ptp_clock_kernel.h>
32#include <linux/sched/rt.h>
33#include <linux/slab.h>
34#include <linux/spi/spi.h>
35#include <linux/spi/spi-mem.h>
36#include <uapi/linux/sched/types.h>
37
38#define CREATE_TRACE_POINTS
39#include <trace/events/spi.h>
40EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
41EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
42
43#include "internals.h"
44
45static DEFINE_IDR(spi_master_idr);
46
47static void spidev_release(struct device *dev)
48{
49 struct spi_device *spi = to_spi_device(dev);
50
51 spi_controller_put(spi->controller);
52 kfree(spi->driver_override);
53 free_percpu(spi->pcpu_statistics);
54 kfree(spi);
55}
56
57static ssize_t
58modalias_show(struct device *dev, struct device_attribute *a, char *buf)
59{
60 const struct spi_device *spi = to_spi_device(dev);
61 int len;
62
63 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
64 if (len != -ENODEV)
65 return len;
66
67 return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
68}
69static DEVICE_ATTR_RO(modalias);
70
71static ssize_t driver_override_store(struct device *dev,
72 struct device_attribute *a,
73 const char *buf, size_t count)
74{
75 struct spi_device *spi = to_spi_device(dev);
76 int ret;
77
78 ret = driver_set_override(dev, &spi->driver_override, buf, count);
79 if (ret)
80 return ret;
81
82 return count;
83}
84
85static ssize_t driver_override_show(struct device *dev,
86 struct device_attribute *a, char *buf)
87{
88 const struct spi_device *spi = to_spi_device(dev);
89 ssize_t len;
90
91 device_lock(dev);
92 len = sysfs_emit(buf, "%s\n", spi->driver_override ? : "");
93 device_unlock(dev);
94 return len;
95}
96static DEVICE_ATTR_RW(driver_override);
97
98static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev)
99{
100 struct spi_statistics __percpu *pcpu_stats;
101
102 if (dev)
103 pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);
104 else
105 pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);
106
107 if (pcpu_stats) {
108 int cpu;
109
110 for_each_possible_cpu(cpu) {
111 struct spi_statistics *stat;
112
113 stat = per_cpu_ptr(pcpu_stats, cpu);
114 u64_stats_init(&stat->syncp);
115 }
116 }
117 return pcpu_stats;
118}
119
120static ssize_t spi_emit_pcpu_stats(struct spi_statistics __percpu *stat,
121 char *buf, size_t offset)
122{
123 u64 val = 0;
124 int i;
125
126 for_each_possible_cpu(i) {
127 const struct spi_statistics *pcpu_stats;
128 u64_stats_t *field;
129 unsigned int start;
130 u64 inc;
131
132 pcpu_stats = per_cpu_ptr(stat, i);
133 field = (void *)pcpu_stats + offset;
134 do {
135 start = u64_stats_fetch_begin(&pcpu_stats->syncp);
136 inc = u64_stats_read(field);
137 } while (u64_stats_fetch_retry(&pcpu_stats->syncp, start));
138 val += inc;
139 }
140 return sysfs_emit(buf, "%llu\n", val);
141}
142
143#define SPI_STATISTICS_ATTRS(field, file) \
144static ssize_t spi_controller_##field##_show(struct device *dev, \
145 struct device_attribute *attr, \
146 char *buf) \
147{ \
148 struct spi_controller *ctlr = container_of(dev, \
149 struct spi_controller, dev); \
150 return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \
151} \
152static struct device_attribute dev_attr_spi_controller_##field = { \
153 .attr = { .name = file, .mode = 0444 }, \
154 .show = spi_controller_##field##_show, \
155}; \
156static ssize_t spi_device_##field##_show(struct device *dev, \
157 struct device_attribute *attr, \
158 char *buf) \
159{ \
160 struct spi_device *spi = to_spi_device(dev); \
161 return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \
162} \
163static struct device_attribute dev_attr_spi_device_##field = { \
164 .attr = { .name = file, .mode = 0444 }, \
165 .show = spi_device_##field##_show, \
166}
167
168#define SPI_STATISTICS_SHOW_NAME(name, file, field) \
169static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \
170 char *buf) \
171{ \
172 return spi_emit_pcpu_stats(stat, buf, \
173 offsetof(struct spi_statistics, field)); \
174} \
175SPI_STATISTICS_ATTRS(name, file)
176
177#define SPI_STATISTICS_SHOW(field) \
178 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
179 field)
180
181SPI_STATISTICS_SHOW(messages);
182SPI_STATISTICS_SHOW(transfers);
183SPI_STATISTICS_SHOW(errors);
184SPI_STATISTICS_SHOW(timedout);
185
186SPI_STATISTICS_SHOW(spi_sync);
187SPI_STATISTICS_SHOW(spi_sync_immediate);
188SPI_STATISTICS_SHOW(spi_async);
189
190SPI_STATISTICS_SHOW(bytes);
191SPI_STATISTICS_SHOW(bytes_rx);
192SPI_STATISTICS_SHOW(bytes_tx);
193
194#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
195 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
196 "transfer_bytes_histo_" number, \
197 transfer_bytes_histo[index])
198SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
199SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
200SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
201SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
202SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
203SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
204SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
205SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
206SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
207SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
208SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
209SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
210SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
211SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
212SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
213SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
214SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
215
216SPI_STATISTICS_SHOW(transfers_split_maxsize);
217
218static struct attribute *spi_dev_attrs[] = {
219 &dev_attr_modalias.attr,
220 &dev_attr_driver_override.attr,
221 NULL,
222};
223
224static const struct attribute_group spi_dev_group = {
225 .attrs = spi_dev_attrs,
226};
227
228static struct attribute *spi_device_statistics_attrs[] = {
229 &dev_attr_spi_device_messages.attr,
230 &dev_attr_spi_device_transfers.attr,
231 &dev_attr_spi_device_errors.attr,
232 &dev_attr_spi_device_timedout.attr,
233 &dev_attr_spi_device_spi_sync.attr,
234 &dev_attr_spi_device_spi_sync_immediate.attr,
235 &dev_attr_spi_device_spi_async.attr,
236 &dev_attr_spi_device_bytes.attr,
237 &dev_attr_spi_device_bytes_rx.attr,
238 &dev_attr_spi_device_bytes_tx.attr,
239 &dev_attr_spi_device_transfer_bytes_histo0.attr,
240 &dev_attr_spi_device_transfer_bytes_histo1.attr,
241 &dev_attr_spi_device_transfer_bytes_histo2.attr,
242 &dev_attr_spi_device_transfer_bytes_histo3.attr,
243 &dev_attr_spi_device_transfer_bytes_histo4.attr,
244 &dev_attr_spi_device_transfer_bytes_histo5.attr,
245 &dev_attr_spi_device_transfer_bytes_histo6.attr,
246 &dev_attr_spi_device_transfer_bytes_histo7.attr,
247 &dev_attr_spi_device_transfer_bytes_histo8.attr,
248 &dev_attr_spi_device_transfer_bytes_histo9.attr,
249 &dev_attr_spi_device_transfer_bytes_histo10.attr,
250 &dev_attr_spi_device_transfer_bytes_histo11.attr,
251 &dev_attr_spi_device_transfer_bytes_histo12.attr,
252 &dev_attr_spi_device_transfer_bytes_histo13.attr,
253 &dev_attr_spi_device_transfer_bytes_histo14.attr,
254 &dev_attr_spi_device_transfer_bytes_histo15.attr,
255 &dev_attr_spi_device_transfer_bytes_histo16.attr,
256 &dev_attr_spi_device_transfers_split_maxsize.attr,
257 NULL,
258};
259
260static const struct attribute_group spi_device_statistics_group = {
261 .name = "statistics",
262 .attrs = spi_device_statistics_attrs,
263};
264
265static const struct attribute_group *spi_dev_groups[] = {
266 &spi_dev_group,
267 &spi_device_statistics_group,
268 NULL,
269};
270
271static struct attribute *spi_controller_statistics_attrs[] = {
272 &dev_attr_spi_controller_messages.attr,
273 &dev_attr_spi_controller_transfers.attr,
274 &dev_attr_spi_controller_errors.attr,
275 &dev_attr_spi_controller_timedout.attr,
276 &dev_attr_spi_controller_spi_sync.attr,
277 &dev_attr_spi_controller_spi_sync_immediate.attr,
278 &dev_attr_spi_controller_spi_async.attr,
279 &dev_attr_spi_controller_bytes.attr,
280 &dev_attr_spi_controller_bytes_rx.attr,
281 &dev_attr_spi_controller_bytes_tx.attr,
282 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
283 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
284 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
285 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
286 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
287 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
288 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
289 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
290 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
291 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
292 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
293 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
294 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
295 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
296 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
297 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
298 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
299 &dev_attr_spi_controller_transfers_split_maxsize.attr,
300 NULL,
301};
302
303static const struct attribute_group spi_controller_statistics_group = {
304 .name = "statistics",
305 .attrs = spi_controller_statistics_attrs,
306};
307
308static const struct attribute_group *spi_master_groups[] = {
309 &spi_controller_statistics_group,
310 NULL,
311};
312
313static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats,
314 struct spi_transfer *xfer,
315 struct spi_message *msg)
316{
317 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
318 struct spi_statistics *stats;
319
320 if (l2len < 0)
321 l2len = 0;
322
323 get_cpu();
324 stats = this_cpu_ptr(pcpu_stats);
325 u64_stats_update_begin(&stats->syncp);
326
327 u64_stats_inc(&stats->transfers);
328 u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
329
330 u64_stats_add(&stats->bytes, xfer->len);
331 if (spi_valid_txbuf(msg, xfer))
332 u64_stats_add(&stats->bytes_tx, xfer->len);
333 if (spi_valid_rxbuf(msg, xfer))
334 u64_stats_add(&stats->bytes_rx, xfer->len);
335
336 u64_stats_update_end(&stats->syncp);
337 put_cpu();
338}
339
340/*
341 * modalias support makes "modprobe $MODALIAS" new-style hotplug work,
342 * and the sysfs version makes coldplug work too.
343 */
344static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)
345{
346 while (id->name[0]) {
347 if (!strcmp(name, id->name))
348 return id;
349 id++;
350 }
351 return NULL;
352}
353
354const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
355{
356 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
357
358 return spi_match_id(sdrv->id_table, sdev->modalias);
359}
360EXPORT_SYMBOL_GPL(spi_get_device_id);
361
362const void *spi_get_device_match_data(const struct spi_device *sdev)
363{
364 const void *match;
365
366 match = device_get_match_data(&sdev->dev);
367 if (match)
368 return match;
369
370 return (const void *)spi_get_device_id(sdev)->driver_data;
371}
372EXPORT_SYMBOL_GPL(spi_get_device_match_data);
373
374static int spi_match_device(struct device *dev, const struct device_driver *drv)
375{
376 const struct spi_device *spi = to_spi_device(dev);
377 const struct spi_driver *sdrv = to_spi_driver(drv);
378
379 /* Check override first, and if set, only use the named driver */
380 if (spi->driver_override)
381 return strcmp(spi->driver_override, drv->name) == 0;
382
383 /* Attempt an OF style match */
384 if (of_driver_match_device(dev, drv))
385 return 1;
386
387 /* Then try ACPI */
388 if (acpi_driver_match_device(dev, drv))
389 return 1;
390
391 if (sdrv->id_table)
392 return !!spi_match_id(sdrv->id_table, spi->modalias);
393
394 return strcmp(spi->modalias, drv->name) == 0;
395}
396
397static int spi_uevent(const struct device *dev, struct kobj_uevent_env *env)
398{
399 const struct spi_device *spi = to_spi_device(dev);
400 int rc;
401
402 rc = acpi_device_uevent_modalias(dev, env);
403 if (rc != -ENODEV)
404 return rc;
405
406 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
407}
408
409static int spi_probe(struct device *dev)
410{
411 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
412 struct spi_device *spi = to_spi_device(dev);
413 int ret;
414
415 ret = of_clk_set_defaults(dev->of_node, false);
416 if (ret)
417 return ret;
418
419 if (dev->of_node) {
420 spi->irq = of_irq_get(dev->of_node, 0);
421 if (spi->irq == -EPROBE_DEFER)
422 return dev_err_probe(dev, -EPROBE_DEFER, "Failed to get irq\n");
423 if (spi->irq < 0)
424 spi->irq = 0;
425 }
426
427 if (has_acpi_companion(dev) && spi->irq < 0) {
428 struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
429
430 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
431 if (spi->irq == -EPROBE_DEFER)
432 return -EPROBE_DEFER;
433 if (spi->irq < 0)
434 spi->irq = 0;
435 }
436
437 ret = dev_pm_domain_attach(dev, true);
438 if (ret)
439 return ret;
440
441 if (sdrv->probe) {
442 ret = sdrv->probe(spi);
443 if (ret)
444 dev_pm_domain_detach(dev, true);
445 }
446
447 return ret;
448}
449
450static void spi_remove(struct device *dev)
451{
452 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
453
454 if (sdrv->remove)
455 sdrv->remove(to_spi_device(dev));
456
457 dev_pm_domain_detach(dev, true);
458}
459
460static void spi_shutdown(struct device *dev)
461{
462 if (dev->driver) {
463 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
464
465 if (sdrv->shutdown)
466 sdrv->shutdown(to_spi_device(dev));
467 }
468}
469
470const struct bus_type spi_bus_type = {
471 .name = "spi",
472 .dev_groups = spi_dev_groups,
473 .match = spi_match_device,
474 .uevent = spi_uevent,
475 .probe = spi_probe,
476 .remove = spi_remove,
477 .shutdown = spi_shutdown,
478};
479EXPORT_SYMBOL_GPL(spi_bus_type);
480
481/**
482 * __spi_register_driver - register a SPI driver
483 * @owner: owner module of the driver to register
484 * @sdrv: the driver to register
485 * Context: can sleep
486 *
487 * Return: zero on success, else a negative error code.
488 */
489int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
490{
491 sdrv->driver.owner = owner;
492 sdrv->driver.bus = &spi_bus_type;
493
494 /*
495 * For Really Good Reasons we use spi: modaliases not of:
496 * modaliases for DT so module autoloading won't work if we
497 * don't have a spi_device_id as well as a compatible string.
498 */
499 if (sdrv->driver.of_match_table) {
500 const struct of_device_id *of_id;
501
502 for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];
503 of_id++) {
504 const char *of_name;
505
506 /* Strip off any vendor prefix */
507 of_name = strnchr(of_id->compatible,
508 sizeof(of_id->compatible), ',');
509 if (of_name)
510 of_name++;
511 else
512 of_name = of_id->compatible;
513
514 if (sdrv->id_table) {
515 const struct spi_device_id *spi_id;
516
517 spi_id = spi_match_id(sdrv->id_table, of_name);
518 if (spi_id)
519 continue;
520 } else {
521 if (strcmp(sdrv->driver.name, of_name) == 0)
522 continue;
523 }
524
525 pr_warn("SPI driver %s has no spi_device_id for %s\n",
526 sdrv->driver.name, of_id->compatible);
527 }
528 }
529
530 return driver_register(&sdrv->driver);
531}
532EXPORT_SYMBOL_GPL(__spi_register_driver);
533
534/*-------------------------------------------------------------------------*/
535
536/*
537 * SPI devices should normally not be created by SPI device drivers; that
538 * would make them board-specific. Similarly with SPI controller drivers.
539 * Device registration normally goes into like arch/.../mach.../board-YYY.c
540 * with other readonly (flashable) information about mainboard devices.
541 */
542
543struct boardinfo {
544 struct list_head list;
545 struct spi_board_info board_info;
546};
547
548static LIST_HEAD(board_list);
549static LIST_HEAD(spi_controller_list);
550
551/*
552 * Used to protect add/del operation for board_info list and
553 * spi_controller list, and their matching process also used
554 * to protect object of type struct idr.
555 */
556static DEFINE_MUTEX(board_lock);
557
558/**
559 * spi_alloc_device - Allocate a new SPI device
560 * @ctlr: Controller to which device is connected
561 * Context: can sleep
562 *
563 * Allows a driver to allocate and initialize a spi_device without
564 * registering it immediately. This allows a driver to directly
565 * fill the spi_device with device parameters before calling
566 * spi_add_device() on it.
567 *
568 * Caller is responsible to call spi_add_device() on the returned
569 * spi_device structure to add it to the SPI controller. If the caller
570 * needs to discard the spi_device without adding it, then it should
571 * call spi_dev_put() on it.
572 *
573 * Return: a pointer to the new device, or NULL.
574 */
575struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
576{
577 struct spi_device *spi;
578
579 if (!spi_controller_get(ctlr))
580 return NULL;
581
582 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
583 if (!spi) {
584 spi_controller_put(ctlr);
585 return NULL;
586 }
587
588 spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);
589 if (!spi->pcpu_statistics) {
590 kfree(spi);
591 spi_controller_put(ctlr);
592 return NULL;
593 }
594
595 spi->controller = ctlr;
596 spi->dev.parent = &ctlr->dev;
597 spi->dev.bus = &spi_bus_type;
598 spi->dev.release = spidev_release;
599 spi->mode = ctlr->buswidth_override_bits;
600
601 device_initialize(&spi->dev);
602 return spi;
603}
604EXPORT_SYMBOL_GPL(spi_alloc_device);
605
606static void spi_dev_set_name(struct spi_device *spi)
607{
608 struct device *dev = &spi->dev;
609 struct fwnode_handle *fwnode = dev_fwnode(dev);
610
611 if (is_acpi_device_node(fwnode)) {
612 dev_set_name(dev, "spi-%s", acpi_dev_name(to_acpi_device_node(fwnode)));
613 return;
614 }
615
616 if (is_software_node(fwnode)) {
617 dev_set_name(dev, "spi-%pfwP", fwnode);
618 return;
619 }
620
621 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
622 spi_get_chipselect(spi, 0));
623}
624
625/*
626 * Zero(0) is a valid physical CS value and can be located at any
627 * logical CS in the spi->chip_select[]. If all the physical CS
628 * are initialized to 0 then It would be difficult to differentiate
629 * between a valid physical CS 0 & an unused logical CS whose physical
630 * CS can be 0. As a solution to this issue initialize all the CS to -1.
631 * Now all the unused logical CS will have -1 physical CS value & can be
632 * ignored while performing physical CS validity checks.
633 */
634#define SPI_INVALID_CS ((s8)-1)
635
636static inline bool is_valid_cs(s8 chip_select)
637{
638 return chip_select != SPI_INVALID_CS;
639}
640
641static inline int spi_dev_check_cs(struct device *dev,
642 struct spi_device *spi, u8 idx,
643 struct spi_device *new_spi, u8 new_idx)
644{
645 u8 cs, cs_new;
646 u8 idx_new;
647
648 cs = spi_get_chipselect(spi, idx);
649 for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) {
650 cs_new = spi_get_chipselect(new_spi, idx_new);
651 if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) {
652 dev_err(dev, "chipselect %u already in use\n", cs_new);
653 return -EBUSY;
654 }
655 }
656 return 0;
657}
658
659static int spi_dev_check(struct device *dev, void *data)
660{
661 struct spi_device *spi = to_spi_device(dev);
662 struct spi_device *new_spi = data;
663 int status, idx;
664
665 if (spi->controller == new_spi->controller) {
666 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
667 status = spi_dev_check_cs(dev, spi, idx, new_spi, 0);
668 if (status)
669 return status;
670 }
671 }
672 return 0;
673}
674
675static void spi_cleanup(struct spi_device *spi)
676{
677 if (spi->controller->cleanup)
678 spi->controller->cleanup(spi);
679}
680
681static int __spi_add_device(struct spi_device *spi)
682{
683 struct spi_controller *ctlr = spi->controller;
684 struct device *dev = ctlr->dev.parent;
685 int status, idx;
686 u8 cs;
687
688 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
689 /* Chipselects are numbered 0..max; validate. */
690 cs = spi_get_chipselect(spi, idx);
691 if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) {
692 dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
693 ctlr->num_chipselect);
694 return -EINVAL;
695 }
696 }
697
698 /*
699 * Make sure that multiple logical CS doesn't map to the same physical CS.
700 * For example, spi->chip_select[0] != spi->chip_select[1] and so on.
701 */
702 if (!spi_controller_is_target(ctlr)) {
703 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
704 status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1);
705 if (status)
706 return status;
707 }
708 }
709
710 /* Set the bus ID string */
711 spi_dev_set_name(spi);
712
713 /*
714 * We need to make sure there's no other device with this
715 * chipselect **BEFORE** we call setup(), else we'll trash
716 * its configuration.
717 */
718 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
719 if (status)
720 return status;
721
722 /* Controller may unregister concurrently */
723 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
724 !device_is_registered(&ctlr->dev)) {
725 return -ENODEV;
726 }
727
728 if (ctlr->cs_gpiods) {
729 u8 cs;
730
731 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
732 cs = spi_get_chipselect(spi, idx);
733 if (is_valid_cs(cs))
734 spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]);
735 }
736 }
737
738 /*
739 * Drivers may modify this initial i/o setup, but will
740 * normally rely on the device being setup. Devices
741 * using SPI_CS_HIGH can't coexist well otherwise...
742 */
743 status = spi_setup(spi);
744 if (status < 0) {
745 dev_err(dev, "can't setup %s, status %d\n",
746 dev_name(&spi->dev), status);
747 return status;
748 }
749
750 /* Device may be bound to an active driver when this returns */
751 status = device_add(&spi->dev);
752 if (status < 0) {
753 dev_err(dev, "can't add %s, status %d\n",
754 dev_name(&spi->dev), status);
755 spi_cleanup(spi);
756 } else {
757 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
758 }
759
760 return status;
761}
762
763/**
764 * spi_add_device - Add spi_device allocated with spi_alloc_device
765 * @spi: spi_device to register
766 *
767 * Companion function to spi_alloc_device. Devices allocated with
768 * spi_alloc_device can be added onto the SPI bus with this function.
769 *
770 * Return: 0 on success; negative errno on failure
771 */
772int spi_add_device(struct spi_device *spi)
773{
774 struct spi_controller *ctlr = spi->controller;
775 int status;
776
777 /* Set the bus ID string */
778 spi_dev_set_name(spi);
779
780 mutex_lock(&ctlr->add_lock);
781 status = __spi_add_device(spi);
782 mutex_unlock(&ctlr->add_lock);
783 return status;
784}
785EXPORT_SYMBOL_GPL(spi_add_device);
786
787static void spi_set_all_cs_unused(struct spi_device *spi)
788{
789 u8 idx;
790
791 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
792 spi_set_chipselect(spi, idx, SPI_INVALID_CS);
793}
794
795/**
796 * spi_new_device - instantiate one new SPI device
797 * @ctlr: Controller to which device is connected
798 * @chip: Describes the SPI device
799 * Context: can sleep
800 *
801 * On typical mainboards, this is purely internal; and it's not needed
802 * after board init creates the hard-wired devices. Some development
803 * platforms may not be able to use spi_register_board_info though, and
804 * this is exported so that for example a USB or parport based adapter
805 * driver could add devices (which it would learn about out-of-band).
806 *
807 * Return: the new device, or NULL.
808 */
809struct spi_device *spi_new_device(struct spi_controller *ctlr,
810 struct spi_board_info *chip)
811{
812 struct spi_device *proxy;
813 int status;
814
815 /*
816 * NOTE: caller did any chip->bus_num checks necessary.
817 *
818 * Also, unless we change the return value convention to use
819 * error-or-pointer (not NULL-or-pointer), troubleshootability
820 * suggests syslogged diagnostics are best here (ugh).
821 */
822
823 proxy = spi_alloc_device(ctlr);
824 if (!proxy)
825 return NULL;
826
827 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
828
829 /* Use provided chip-select for proxy device */
830 spi_set_all_cs_unused(proxy);
831 spi_set_chipselect(proxy, 0, chip->chip_select);
832
833 proxy->max_speed_hz = chip->max_speed_hz;
834 proxy->mode = chip->mode;
835 proxy->irq = chip->irq;
836 strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
837 proxy->dev.platform_data = (void *) chip->platform_data;
838 proxy->controller_data = chip->controller_data;
839 proxy->controller_state = NULL;
840 /*
841 * By default spi->chip_select[0] will hold the physical CS number,
842 * so set bit 0 in spi->cs_index_mask.
843 */
844 proxy->cs_index_mask = BIT(0);
845
846 if (chip->swnode) {
847 status = device_add_software_node(&proxy->dev, chip->swnode);
848 if (status) {
849 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
850 chip->modalias, status);
851 goto err_dev_put;
852 }
853 }
854
855 status = spi_add_device(proxy);
856 if (status < 0)
857 goto err_dev_put;
858
859 return proxy;
860
861err_dev_put:
862 device_remove_software_node(&proxy->dev);
863 spi_dev_put(proxy);
864 return NULL;
865}
866EXPORT_SYMBOL_GPL(spi_new_device);
867
868/**
869 * spi_unregister_device - unregister a single SPI device
870 * @spi: spi_device to unregister
871 *
872 * Start making the passed SPI device vanish. Normally this would be handled
873 * by spi_unregister_controller().
874 */
875void spi_unregister_device(struct spi_device *spi)
876{
877 if (!spi)
878 return;
879
880 if (spi->dev.of_node) {
881 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
882 of_node_put(spi->dev.of_node);
883 }
884 if (ACPI_COMPANION(&spi->dev))
885 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
886 device_remove_software_node(&spi->dev);
887 device_del(&spi->dev);
888 spi_cleanup(spi);
889 put_device(&spi->dev);
890}
891EXPORT_SYMBOL_GPL(spi_unregister_device);
892
893static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
894 struct spi_board_info *bi)
895{
896 struct spi_device *dev;
897
898 if (ctlr->bus_num != bi->bus_num)
899 return;
900
901 dev = spi_new_device(ctlr, bi);
902 if (!dev)
903 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
904 bi->modalias);
905}
906
907/**
908 * spi_register_board_info - register SPI devices for a given board
909 * @info: array of chip descriptors
910 * @n: how many descriptors are provided
911 * Context: can sleep
912 *
913 * Board-specific early init code calls this (probably during arch_initcall)
914 * with segments of the SPI device table. Any device nodes are created later,
915 * after the relevant parent SPI controller (bus_num) is defined. We keep
916 * this table of devices forever, so that reloading a controller driver will
917 * not make Linux forget about these hard-wired devices.
918 *
919 * Other code can also call this, e.g. a particular add-on board might provide
920 * SPI devices through its expansion connector, so code initializing that board
921 * would naturally declare its SPI devices.
922 *
923 * The board info passed can safely be __initdata ... but be careful of
924 * any embedded pointers (platform_data, etc), they're copied as-is.
925 *
926 * Return: zero on success, else a negative error code.
927 */
928int spi_register_board_info(struct spi_board_info const *info, unsigned n)
929{
930 struct boardinfo *bi;
931 int i;
932
933 if (!n)
934 return 0;
935
936 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
937 if (!bi)
938 return -ENOMEM;
939
940 for (i = 0; i < n; i++, bi++, info++) {
941 struct spi_controller *ctlr;
942
943 memcpy(&bi->board_info, info, sizeof(*info));
944
945 mutex_lock(&board_lock);
946 list_add_tail(&bi->list, &board_list);
947 list_for_each_entry(ctlr, &spi_controller_list, list)
948 spi_match_controller_to_boardinfo(ctlr,
949 &bi->board_info);
950 mutex_unlock(&board_lock);
951 }
952
953 return 0;
954}
955
956/*-------------------------------------------------------------------------*/
957
958/* Core methods for SPI resource management */
959
960/**
961 * spi_res_alloc - allocate a spi resource that is life-cycle managed
962 * during the processing of a spi_message while using
963 * spi_transfer_one
964 * @spi: the SPI device for which we allocate memory
965 * @release: the release code to execute for this resource
966 * @size: size to alloc and return
967 * @gfp: GFP allocation flags
968 *
969 * Return: the pointer to the allocated data
970 *
971 * This may get enhanced in the future to allocate from a memory pool
972 * of the @spi_device or @spi_controller to avoid repeated allocations.
973 */
974static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,
975 size_t size, gfp_t gfp)
976{
977 struct spi_res *sres;
978
979 sres = kzalloc(sizeof(*sres) + size, gfp);
980 if (!sres)
981 return NULL;
982
983 INIT_LIST_HEAD(&sres->entry);
984 sres->release = release;
985
986 return sres->data;
987}
988
989/**
990 * spi_res_free - free an SPI resource
991 * @res: pointer to the custom data of a resource
992 */
993static void spi_res_free(void *res)
994{
995 struct spi_res *sres = container_of(res, struct spi_res, data);
996
997 WARN_ON(!list_empty(&sres->entry));
998 kfree(sres);
999}
1000
1001/**
1002 * spi_res_add - add a spi_res to the spi_message
1003 * @message: the SPI message
1004 * @res: the spi_resource
1005 */
1006static void spi_res_add(struct spi_message *message, void *res)
1007{
1008 struct spi_res *sres = container_of(res, struct spi_res, data);
1009
1010 WARN_ON(!list_empty(&sres->entry));
1011 list_add_tail(&sres->entry, &message->resources);
1012}
1013
1014/**
1015 * spi_res_release - release all SPI resources for this message
1016 * @ctlr: the @spi_controller
1017 * @message: the @spi_message
1018 */
1019static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
1020{
1021 struct spi_res *res, *tmp;
1022
1023 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
1024 if (res->release)
1025 res->release(ctlr, message, res->data);
1026
1027 list_del(&res->entry);
1028
1029 kfree(res);
1030 }
1031}
1032
1033/*-------------------------------------------------------------------------*/
1034#define spi_for_each_valid_cs(spi, idx) \
1035 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) \
1036 if (!(spi->cs_index_mask & BIT(idx))) {} else
1037
1038static inline bool spi_is_last_cs(struct spi_device *spi)
1039{
1040 u8 idx;
1041 bool last = false;
1042
1043 spi_for_each_valid_cs(spi, idx) {
1044 if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx))
1045 last = true;
1046 }
1047 return last;
1048}
1049
1050static void spi_toggle_csgpiod(struct spi_device *spi, u8 idx, bool enable, bool activate)
1051{
1052 /*
1053 * Historically ACPI has no means of the GPIO polarity and
1054 * thus the SPISerialBus() resource defines it on the per-chip
1055 * basis. In order to avoid a chain of negations, the GPIO
1056 * polarity is considered being Active High. Even for the cases
1057 * when _DSD() is involved (in the updated versions of ACPI)
1058 * the GPIO CS polarity must be defined Active High to avoid
1059 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
1060 * into account.
1061 */
1062 if (has_acpi_companion(&spi->dev))
1063 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), !enable);
1064 else
1065 /* Polarity handled by GPIO library */
1066 gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), activate);
1067
1068 if (activate)
1069 spi_delay_exec(&spi->cs_setup, NULL);
1070 else
1071 spi_delay_exec(&spi->cs_inactive, NULL);
1072}
1073
1074static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
1075{
1076 bool activate = enable;
1077 u8 idx;
1078
1079 /*
1080 * Avoid calling into the driver (or doing delays) if the chip select
1081 * isn't actually changing from the last time this was called.
1082 */
1083 if (!force && ((enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&
1084 spi_is_last_cs(spi)) ||
1085 (!enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&
1086 !spi_is_last_cs(spi))) &&
1087 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
1088 return;
1089
1090 trace_spi_set_cs(spi, activate);
1091
1092 spi->controller->last_cs_index_mask = spi->cs_index_mask;
1093 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
1094 spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS;
1095 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
1096
1097 if (spi->mode & SPI_CS_HIGH)
1098 enable = !enable;
1099
1100 /*
1101 * Handle chip select delays for GPIO based CS or controllers without
1102 * programmable chip select timing.
1103 */
1104 if ((spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) && !activate)
1105 spi_delay_exec(&spi->cs_hold, NULL);
1106
1107 if (spi_is_csgpiod(spi)) {
1108 if (!(spi->mode & SPI_NO_CS)) {
1109 spi_for_each_valid_cs(spi, idx) {
1110 if (spi_get_csgpiod(spi, idx))
1111 spi_toggle_csgpiod(spi, idx, enable, activate);
1112 }
1113 }
1114 /* Some SPI masters need both GPIO CS & slave_select */
1115 if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) &&
1116 spi->controller->set_cs)
1117 spi->controller->set_cs(spi, !enable);
1118 } else if (spi->controller->set_cs) {
1119 spi->controller->set_cs(spi, !enable);
1120 }
1121
1122 if (spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) {
1123 if (activate)
1124 spi_delay_exec(&spi->cs_setup, NULL);
1125 else
1126 spi_delay_exec(&spi->cs_inactive, NULL);
1127 }
1128}
1129
1130#ifdef CONFIG_HAS_DMA
1131static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,
1132 struct sg_table *sgt, void *buf, size_t len,
1133 enum dma_data_direction dir, unsigned long attrs)
1134{
1135 const bool vmalloced_buf = is_vmalloc_addr(buf);
1136 unsigned int max_seg_size = dma_get_max_seg_size(dev);
1137#ifdef CONFIG_HIGHMEM
1138 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
1139 (unsigned long)buf < (PKMAP_BASE +
1140 (LAST_PKMAP * PAGE_SIZE)));
1141#else
1142 const bool kmap_buf = false;
1143#endif
1144 int desc_len;
1145 int sgs;
1146 struct page *vm_page;
1147 struct scatterlist *sg;
1148 void *sg_buf;
1149 size_t min;
1150 int i, ret;
1151
1152 if (vmalloced_buf || kmap_buf) {
1153 desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);
1154 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
1155 } else if (virt_addr_valid(buf)) {
1156 desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);
1157 sgs = DIV_ROUND_UP(len, desc_len);
1158 } else {
1159 return -EINVAL;
1160 }
1161
1162 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
1163 if (ret != 0)
1164 return ret;
1165
1166 sg = &sgt->sgl[0];
1167 for (i = 0; i < sgs; i++) {
1168
1169 if (vmalloced_buf || kmap_buf) {
1170 /*
1171 * Next scatterlist entry size is the minimum between
1172 * the desc_len and the remaining buffer length that
1173 * fits in a page.
1174 */
1175 min = min_t(size_t, desc_len,
1176 min_t(size_t, len,
1177 PAGE_SIZE - offset_in_page(buf)));
1178 if (vmalloced_buf)
1179 vm_page = vmalloc_to_page(buf);
1180 else
1181 vm_page = kmap_to_page(buf);
1182 if (!vm_page) {
1183 sg_free_table(sgt);
1184 return -ENOMEM;
1185 }
1186 sg_set_page(sg, vm_page,
1187 min, offset_in_page(buf));
1188 } else {
1189 min = min_t(size_t, len, desc_len);
1190 sg_buf = buf;
1191 sg_set_buf(sg, sg_buf, min);
1192 }
1193
1194 buf += min;
1195 len -= min;
1196 sg = sg_next(sg);
1197 }
1198
1199 ret = dma_map_sgtable(dev, sgt, dir, attrs);
1200 if (ret < 0) {
1201 sg_free_table(sgt);
1202 return ret;
1203 }
1204
1205 return 0;
1206}
1207
1208int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
1209 struct sg_table *sgt, void *buf, size_t len,
1210 enum dma_data_direction dir)
1211{
1212 return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0);
1213}
1214
1215static void spi_unmap_buf_attrs(struct spi_controller *ctlr,
1216 struct device *dev, struct sg_table *sgt,
1217 enum dma_data_direction dir,
1218 unsigned long attrs)
1219{
1220 dma_unmap_sgtable(dev, sgt, dir, attrs);
1221 sg_free_table(sgt);
1222 sgt->orig_nents = 0;
1223 sgt->nents = 0;
1224}
1225
1226void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
1227 struct sg_table *sgt, enum dma_data_direction dir)
1228{
1229 spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);
1230}
1231
1232static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1233{
1234 struct device *tx_dev, *rx_dev;
1235 struct spi_transfer *xfer;
1236 int ret;
1237
1238 if (!ctlr->can_dma)
1239 return 0;
1240
1241 if (ctlr->dma_tx)
1242 tx_dev = ctlr->dma_tx->device->dev;
1243 else if (ctlr->dma_map_dev)
1244 tx_dev = ctlr->dma_map_dev;
1245 else
1246 tx_dev = ctlr->dev.parent;
1247
1248 if (ctlr->dma_rx)
1249 rx_dev = ctlr->dma_rx->device->dev;
1250 else if (ctlr->dma_map_dev)
1251 rx_dev = ctlr->dma_map_dev;
1252 else
1253 rx_dev = ctlr->dev.parent;
1254
1255 ret = -ENOMSG;
1256 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1257 /* The sync is done before each transfer. */
1258 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1259
1260 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1261 continue;
1262
1263 if (xfer->tx_buf != NULL) {
1264 ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1265 (void *)xfer->tx_buf,
1266 xfer->len, DMA_TO_DEVICE,
1267 attrs);
1268 if (ret != 0)
1269 return ret;
1270
1271 xfer->tx_sg_mapped = true;
1272 }
1273
1274 if (xfer->rx_buf != NULL) {
1275 ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1276 xfer->rx_buf, xfer->len,
1277 DMA_FROM_DEVICE, attrs);
1278 if (ret != 0) {
1279 spi_unmap_buf_attrs(ctlr, tx_dev,
1280 &xfer->tx_sg, DMA_TO_DEVICE,
1281 attrs);
1282
1283 return ret;
1284 }
1285
1286 xfer->rx_sg_mapped = true;
1287 }
1288 }
1289 /* No transfer has been mapped, bail out with success */
1290 if (ret)
1291 return 0;
1292
1293 ctlr->cur_rx_dma_dev = rx_dev;
1294 ctlr->cur_tx_dma_dev = tx_dev;
1295
1296 return 0;
1297}
1298
1299static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1300{
1301 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1302 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1303 struct spi_transfer *xfer;
1304
1305 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1306 /* The sync has already been done after each transfer. */
1307 unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;
1308
1309 if (xfer->rx_sg_mapped)
1310 spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,
1311 DMA_FROM_DEVICE, attrs);
1312 xfer->rx_sg_mapped = false;
1313
1314 if (xfer->tx_sg_mapped)
1315 spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,
1316 DMA_TO_DEVICE, attrs);
1317 xfer->tx_sg_mapped = false;
1318 }
1319
1320 return 0;
1321}
1322
1323static void spi_dma_sync_for_device(struct spi_controller *ctlr,
1324 struct spi_transfer *xfer)
1325{
1326 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1327 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1328
1329 if (xfer->tx_sg_mapped)
1330 dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1331 if (xfer->rx_sg_mapped)
1332 dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1333}
1334
1335static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,
1336 struct spi_transfer *xfer)
1337{
1338 struct device *rx_dev = ctlr->cur_rx_dma_dev;
1339 struct device *tx_dev = ctlr->cur_tx_dma_dev;
1340
1341 if (xfer->rx_sg_mapped)
1342 dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1343 if (xfer->tx_sg_mapped)
1344 dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1345}
1346#else /* !CONFIG_HAS_DMA */
1347static inline int __spi_map_msg(struct spi_controller *ctlr,
1348 struct spi_message *msg)
1349{
1350 return 0;
1351}
1352
1353static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1354 struct spi_message *msg)
1355{
1356 return 0;
1357}
1358
1359static void spi_dma_sync_for_device(struct spi_controller *ctrl,
1360 struct spi_transfer *xfer)
1361{
1362}
1363
1364static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,
1365 struct spi_transfer *xfer)
1366{
1367}
1368#endif /* !CONFIG_HAS_DMA */
1369
1370static inline int spi_unmap_msg(struct spi_controller *ctlr,
1371 struct spi_message *msg)
1372{
1373 struct spi_transfer *xfer;
1374
1375 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1376 /*
1377 * Restore the original value of tx_buf or rx_buf if they are
1378 * NULL.
1379 */
1380 if (xfer->tx_buf == ctlr->dummy_tx)
1381 xfer->tx_buf = NULL;
1382 if (xfer->rx_buf == ctlr->dummy_rx)
1383 xfer->rx_buf = NULL;
1384 }
1385
1386 return __spi_unmap_msg(ctlr, msg);
1387}
1388
1389static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1390{
1391 struct spi_transfer *xfer;
1392 void *tmp;
1393 unsigned int max_tx, max_rx;
1394
1395 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1396 && !(msg->spi->mode & SPI_3WIRE)) {
1397 max_tx = 0;
1398 max_rx = 0;
1399
1400 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1401 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1402 !xfer->tx_buf)
1403 max_tx = max(xfer->len, max_tx);
1404 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1405 !xfer->rx_buf)
1406 max_rx = max(xfer->len, max_rx);
1407 }
1408
1409 if (max_tx) {
1410 tmp = krealloc(ctlr->dummy_tx, max_tx,
1411 GFP_KERNEL | GFP_DMA | __GFP_ZERO);
1412 if (!tmp)
1413 return -ENOMEM;
1414 ctlr->dummy_tx = tmp;
1415 }
1416
1417 if (max_rx) {
1418 tmp = krealloc(ctlr->dummy_rx, max_rx,
1419 GFP_KERNEL | GFP_DMA);
1420 if (!tmp)
1421 return -ENOMEM;
1422 ctlr->dummy_rx = tmp;
1423 }
1424
1425 if (max_tx || max_rx) {
1426 list_for_each_entry(xfer, &msg->transfers,
1427 transfer_list) {
1428 if (!xfer->len)
1429 continue;
1430 if (!xfer->tx_buf)
1431 xfer->tx_buf = ctlr->dummy_tx;
1432 if (!xfer->rx_buf)
1433 xfer->rx_buf = ctlr->dummy_rx;
1434 }
1435 }
1436 }
1437
1438 return __spi_map_msg(ctlr, msg);
1439}
1440
1441static int spi_transfer_wait(struct spi_controller *ctlr,
1442 struct spi_message *msg,
1443 struct spi_transfer *xfer)
1444{
1445 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1446 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1447 u32 speed_hz = xfer->speed_hz;
1448 unsigned long long ms;
1449
1450 if (spi_controller_is_target(ctlr)) {
1451 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1452 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1453 return -EINTR;
1454 }
1455 } else {
1456 if (!speed_hz)
1457 speed_hz = 100000;
1458
1459 /*
1460 * For each byte we wait for 8 cycles of the SPI clock.
1461 * Since speed is defined in Hz and we want milliseconds,
1462 * use respective multiplier, but before the division,
1463 * otherwise we may get 0 for short transfers.
1464 */
1465 ms = 8LL * MSEC_PER_SEC * xfer->len;
1466 do_div(ms, speed_hz);
1467
1468 /*
1469 * Increase it twice and add 200 ms tolerance, use
1470 * predefined maximum in case of overflow.
1471 */
1472 ms += ms + 200;
1473 if (ms > UINT_MAX)
1474 ms = UINT_MAX;
1475
1476 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1477 msecs_to_jiffies(ms));
1478
1479 if (ms == 0) {
1480 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1481 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1482 dev_err(&msg->spi->dev,
1483 "SPI transfer timed out\n");
1484 return -ETIMEDOUT;
1485 }
1486
1487 if (xfer->error & SPI_TRANS_FAIL_IO)
1488 return -EIO;
1489 }
1490
1491 return 0;
1492}
1493
1494static void _spi_transfer_delay_ns(u32 ns)
1495{
1496 if (!ns)
1497 return;
1498 if (ns <= NSEC_PER_USEC) {
1499 ndelay(ns);
1500 } else {
1501 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1502
1503 if (us <= 10)
1504 udelay(us);
1505 else
1506 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1507 }
1508}
1509
1510int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1511{
1512 u32 delay = _delay->value;
1513 u32 unit = _delay->unit;
1514 u32 hz;
1515
1516 if (!delay)
1517 return 0;
1518
1519 switch (unit) {
1520 case SPI_DELAY_UNIT_USECS:
1521 delay *= NSEC_PER_USEC;
1522 break;
1523 case SPI_DELAY_UNIT_NSECS:
1524 /* Nothing to do here */
1525 break;
1526 case SPI_DELAY_UNIT_SCK:
1527 /* Clock cycles need to be obtained from spi_transfer */
1528 if (!xfer)
1529 return -EINVAL;
1530 /*
1531 * If there is unknown effective speed, approximate it
1532 * by underestimating with half of the requested Hz.
1533 */
1534 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1535 if (!hz)
1536 return -EINVAL;
1537
1538 /* Convert delay to nanoseconds */
1539 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1540 break;
1541 default:
1542 return -EINVAL;
1543 }
1544
1545 return delay;
1546}
1547EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1548
1549int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1550{
1551 int delay;
1552
1553 might_sleep();
1554
1555 if (!_delay)
1556 return -EINVAL;
1557
1558 delay = spi_delay_to_ns(_delay, xfer);
1559 if (delay < 0)
1560 return delay;
1561
1562 _spi_transfer_delay_ns(delay);
1563
1564 return 0;
1565}
1566EXPORT_SYMBOL_GPL(spi_delay_exec);
1567
1568static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1569 struct spi_transfer *xfer)
1570{
1571 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1572 u32 delay = xfer->cs_change_delay.value;
1573 u32 unit = xfer->cs_change_delay.unit;
1574 int ret;
1575
1576 /* Return early on "fast" mode - for everything but USECS */
1577 if (!delay) {
1578 if (unit == SPI_DELAY_UNIT_USECS)
1579 _spi_transfer_delay_ns(default_delay_ns);
1580 return;
1581 }
1582
1583 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1584 if (ret) {
1585 dev_err_once(&msg->spi->dev,
1586 "Use of unsupported delay unit %i, using default of %luus\n",
1587 unit, default_delay_ns / NSEC_PER_USEC);
1588 _spi_transfer_delay_ns(default_delay_ns);
1589 }
1590}
1591
1592void spi_transfer_cs_change_delay_exec(struct spi_message *msg,
1593 struct spi_transfer *xfer)
1594{
1595 _spi_transfer_cs_change_delay(msg, xfer);
1596}
1597EXPORT_SYMBOL_GPL(spi_transfer_cs_change_delay_exec);
1598
1599/*
1600 * spi_transfer_one_message - Default implementation of transfer_one_message()
1601 *
1602 * This is a standard implementation of transfer_one_message() for
1603 * drivers which implement a transfer_one() operation. It provides
1604 * standard handling of delays and chip select management.
1605 */
1606static int spi_transfer_one_message(struct spi_controller *ctlr,
1607 struct spi_message *msg)
1608{
1609 struct spi_transfer *xfer;
1610 bool keep_cs = false;
1611 int ret = 0;
1612 struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;
1613 struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;
1614
1615 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
1616 spi_set_cs(msg->spi, !xfer->cs_off, false);
1617
1618 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1619 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1620
1621 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1622 trace_spi_transfer_start(msg, xfer);
1623
1624 spi_statistics_add_transfer_stats(statm, xfer, msg);
1625 spi_statistics_add_transfer_stats(stats, xfer, msg);
1626
1627 if (!ctlr->ptp_sts_supported) {
1628 xfer->ptp_sts_word_pre = 0;
1629 ptp_read_system_prets(xfer->ptp_sts);
1630 }
1631
1632 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1633 reinit_completion(&ctlr->xfer_completion);
1634
1635fallback_pio:
1636 spi_dma_sync_for_device(ctlr, xfer);
1637 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1638 if (ret < 0) {
1639 spi_dma_sync_for_cpu(ctlr, xfer);
1640
1641 if ((xfer->tx_sg_mapped || xfer->rx_sg_mapped) &&
1642 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1643 __spi_unmap_msg(ctlr, msg);
1644 ctlr->fallback = true;
1645 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1646 goto fallback_pio;
1647 }
1648
1649 SPI_STATISTICS_INCREMENT_FIELD(statm,
1650 errors);
1651 SPI_STATISTICS_INCREMENT_FIELD(stats,
1652 errors);
1653 dev_err(&msg->spi->dev,
1654 "SPI transfer failed: %d\n", ret);
1655 goto out;
1656 }
1657
1658 if (ret > 0) {
1659 ret = spi_transfer_wait(ctlr, msg, xfer);
1660 if (ret < 0)
1661 msg->status = ret;
1662 }
1663
1664 spi_dma_sync_for_cpu(ctlr, xfer);
1665 } else {
1666 if (xfer->len)
1667 dev_err(&msg->spi->dev,
1668 "Bufferless transfer has length %u\n",
1669 xfer->len);
1670 }
1671
1672 if (!ctlr->ptp_sts_supported) {
1673 ptp_read_system_postts(xfer->ptp_sts);
1674 xfer->ptp_sts_word_post = xfer->len;
1675 }
1676
1677 trace_spi_transfer_stop(msg, xfer);
1678
1679 if (msg->status != -EINPROGRESS)
1680 goto out;
1681
1682 spi_transfer_delay_exec(xfer);
1683
1684 if (xfer->cs_change) {
1685 if (list_is_last(&xfer->transfer_list,
1686 &msg->transfers)) {
1687 keep_cs = true;
1688 } else {
1689 if (!xfer->cs_off)
1690 spi_set_cs(msg->spi, false, false);
1691 _spi_transfer_cs_change_delay(msg, xfer);
1692 if (!list_next_entry(xfer, transfer_list)->cs_off)
1693 spi_set_cs(msg->spi, true, false);
1694 }
1695 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
1696 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
1697 spi_set_cs(msg->spi, xfer->cs_off, false);
1698 }
1699
1700 msg->actual_length += xfer->len;
1701 }
1702
1703out:
1704 if (ret != 0 || !keep_cs)
1705 spi_set_cs(msg->spi, false, false);
1706
1707 if (msg->status == -EINPROGRESS)
1708 msg->status = ret;
1709
1710 if (msg->status && ctlr->handle_err)
1711 ctlr->handle_err(ctlr, msg);
1712
1713 spi_finalize_current_message(ctlr);
1714
1715 return ret;
1716}
1717
1718/**
1719 * spi_finalize_current_transfer - report completion of a transfer
1720 * @ctlr: the controller reporting completion
1721 *
1722 * Called by SPI drivers using the core transfer_one_message()
1723 * implementation to notify it that the current interrupt driven
1724 * transfer has finished and the next one may be scheduled.
1725 */
1726void spi_finalize_current_transfer(struct spi_controller *ctlr)
1727{
1728 complete(&ctlr->xfer_completion);
1729}
1730EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1731
1732static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1733{
1734 if (ctlr->auto_runtime_pm) {
1735 pm_runtime_mark_last_busy(ctlr->dev.parent);
1736 pm_runtime_put_autosuspend(ctlr->dev.parent);
1737 }
1738}
1739
1740static int __spi_pump_transfer_message(struct spi_controller *ctlr,
1741 struct spi_message *msg, bool was_busy)
1742{
1743 struct spi_transfer *xfer;
1744 int ret;
1745
1746 if (!was_busy && ctlr->auto_runtime_pm) {
1747 ret = pm_runtime_get_sync(ctlr->dev.parent);
1748 if (ret < 0) {
1749 pm_runtime_put_noidle(ctlr->dev.parent);
1750 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1751 ret);
1752
1753 msg->status = ret;
1754 spi_finalize_current_message(ctlr);
1755
1756 return ret;
1757 }
1758 }
1759
1760 if (!was_busy)
1761 trace_spi_controller_busy(ctlr);
1762
1763 if (!was_busy && ctlr->prepare_transfer_hardware) {
1764 ret = ctlr->prepare_transfer_hardware(ctlr);
1765 if (ret) {
1766 dev_err(&ctlr->dev,
1767 "failed to prepare transfer hardware: %d\n",
1768 ret);
1769
1770 if (ctlr->auto_runtime_pm)
1771 pm_runtime_put(ctlr->dev.parent);
1772
1773 msg->status = ret;
1774 spi_finalize_current_message(ctlr);
1775
1776 return ret;
1777 }
1778 }
1779
1780 trace_spi_message_start(msg);
1781
1782 if (ctlr->prepare_message) {
1783 ret = ctlr->prepare_message(ctlr, msg);
1784 if (ret) {
1785 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1786 ret);
1787 msg->status = ret;
1788 spi_finalize_current_message(ctlr);
1789 return ret;
1790 }
1791 msg->prepared = true;
1792 }
1793
1794 ret = spi_map_msg(ctlr, msg);
1795 if (ret) {
1796 msg->status = ret;
1797 spi_finalize_current_message(ctlr);
1798 return ret;
1799 }
1800
1801 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1802 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1803 xfer->ptp_sts_word_pre = 0;
1804 ptp_read_system_prets(xfer->ptp_sts);
1805 }
1806 }
1807
1808 /*
1809 * Drivers implementation of transfer_one_message() must arrange for
1810 * spi_finalize_current_message() to get called. Most drivers will do
1811 * this in the calling context, but some don't. For those cases, a
1812 * completion is used to guarantee that this function does not return
1813 * until spi_finalize_current_message() is done accessing
1814 * ctlr->cur_msg.
1815 * Use of the following two flags enable to opportunistically skip the
1816 * use of the completion since its use involves expensive spin locks.
1817 * In case of a race with the context that calls
1818 * spi_finalize_current_message() the completion will always be used,
1819 * due to strict ordering of these flags using barriers.
1820 */
1821 WRITE_ONCE(ctlr->cur_msg_incomplete, true);
1822 WRITE_ONCE(ctlr->cur_msg_need_completion, false);
1823 reinit_completion(&ctlr->cur_msg_completion);
1824 smp_wmb(); /* Make these available to spi_finalize_current_message() */
1825
1826 ret = ctlr->transfer_one_message(ctlr, msg);
1827 if (ret) {
1828 dev_err(&ctlr->dev,
1829 "failed to transfer one message from queue\n");
1830 return ret;
1831 }
1832
1833 WRITE_ONCE(ctlr->cur_msg_need_completion, true);
1834 smp_mb(); /* See spi_finalize_current_message()... */
1835 if (READ_ONCE(ctlr->cur_msg_incomplete))
1836 wait_for_completion(&ctlr->cur_msg_completion);
1837
1838 return 0;
1839}
1840
1841/**
1842 * __spi_pump_messages - function which processes SPI message queue
1843 * @ctlr: controller to process queue for
1844 * @in_kthread: true if we are in the context of the message pump thread
1845 *
1846 * This function checks if there is any SPI message in the queue that
1847 * needs processing and if so call out to the driver to initialize hardware
1848 * and transfer each message.
1849 *
1850 * Note that it is called both from the kthread itself and also from
1851 * inside spi_sync(); the queue extraction handling at the top of the
1852 * function should deal with this safely.
1853 */
1854static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1855{
1856 struct spi_message *msg;
1857 bool was_busy = false;
1858 unsigned long flags;
1859 int ret;
1860
1861 /* Take the I/O mutex */
1862 mutex_lock(&ctlr->io_mutex);
1863
1864 /* Lock queue */
1865 spin_lock_irqsave(&ctlr->queue_lock, flags);
1866
1867 /* Make sure we are not already running a message */
1868 if (ctlr->cur_msg)
1869 goto out_unlock;
1870
1871 /* Check if the queue is idle */
1872 if (list_empty(&ctlr->queue) || !ctlr->running) {
1873 if (!ctlr->busy)
1874 goto out_unlock;
1875
1876 /* Defer any non-atomic teardown to the thread */
1877 if (!in_kthread) {
1878 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1879 !ctlr->unprepare_transfer_hardware) {
1880 spi_idle_runtime_pm(ctlr);
1881 ctlr->busy = false;
1882 ctlr->queue_empty = true;
1883 trace_spi_controller_idle(ctlr);
1884 } else {
1885 kthread_queue_work(ctlr->kworker,
1886 &ctlr->pump_messages);
1887 }
1888 goto out_unlock;
1889 }
1890
1891 ctlr->busy = false;
1892 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1893
1894 kfree(ctlr->dummy_rx);
1895 ctlr->dummy_rx = NULL;
1896 kfree(ctlr->dummy_tx);
1897 ctlr->dummy_tx = NULL;
1898 if (ctlr->unprepare_transfer_hardware &&
1899 ctlr->unprepare_transfer_hardware(ctlr))
1900 dev_err(&ctlr->dev,
1901 "failed to unprepare transfer hardware\n");
1902 spi_idle_runtime_pm(ctlr);
1903 trace_spi_controller_idle(ctlr);
1904
1905 spin_lock_irqsave(&ctlr->queue_lock, flags);
1906 ctlr->queue_empty = true;
1907 goto out_unlock;
1908 }
1909
1910 /* Extract head of queue */
1911 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1912 ctlr->cur_msg = msg;
1913
1914 list_del_init(&msg->queue);
1915 if (ctlr->busy)
1916 was_busy = true;
1917 else
1918 ctlr->busy = true;
1919 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1920
1921 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
1922 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1923
1924 ctlr->cur_msg = NULL;
1925 ctlr->fallback = false;
1926
1927 mutex_unlock(&ctlr->io_mutex);
1928
1929 /* Prod the scheduler in case transfer_one() was busy waiting */
1930 if (!ret)
1931 cond_resched();
1932 return;
1933
1934out_unlock:
1935 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1936 mutex_unlock(&ctlr->io_mutex);
1937}
1938
1939/**
1940 * spi_pump_messages - kthread work function which processes spi message queue
1941 * @work: pointer to kthread work struct contained in the controller struct
1942 */
1943static void spi_pump_messages(struct kthread_work *work)
1944{
1945 struct spi_controller *ctlr =
1946 container_of(work, struct spi_controller, pump_messages);
1947
1948 __spi_pump_messages(ctlr, true);
1949}
1950
1951/**
1952 * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp
1953 * @ctlr: Pointer to the spi_controller structure of the driver
1954 * @xfer: Pointer to the transfer being timestamped
1955 * @progress: How many words (not bytes) have been transferred so far
1956 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1957 * transfer, for less jitter in time measurement. Only compatible
1958 * with PIO drivers. If true, must follow up with
1959 * spi_take_timestamp_post or otherwise system will crash.
1960 * WARNING: for fully predictable results, the CPU frequency must
1961 * also be under control (governor).
1962 *
1963 * This is a helper for drivers to collect the beginning of the TX timestamp
1964 * for the requested byte from the SPI transfer. The frequency with which this
1965 * function must be called (once per word, once for the whole transfer, once
1966 * per batch of words etc) is arbitrary as long as the @tx buffer offset is
1967 * greater than or equal to the requested byte at the time of the call. The
1968 * timestamp is only taken once, at the first such call. It is assumed that
1969 * the driver advances its @tx buffer pointer monotonically.
1970 */
1971void spi_take_timestamp_pre(struct spi_controller *ctlr,
1972 struct spi_transfer *xfer,
1973 size_t progress, bool irqs_off)
1974{
1975 if (!xfer->ptp_sts)
1976 return;
1977
1978 if (xfer->timestamped)
1979 return;
1980
1981 if (progress > xfer->ptp_sts_word_pre)
1982 return;
1983
1984 /* Capture the resolution of the timestamp */
1985 xfer->ptp_sts_word_pre = progress;
1986
1987 if (irqs_off) {
1988 local_irq_save(ctlr->irq_flags);
1989 preempt_disable();
1990 }
1991
1992 ptp_read_system_prets(xfer->ptp_sts);
1993}
1994EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1995
1996/**
1997 * spi_take_timestamp_post - helper to collect the end of the TX timestamp
1998 * @ctlr: Pointer to the spi_controller structure of the driver
1999 * @xfer: Pointer to the transfer being timestamped
2000 * @progress: How many words (not bytes) have been transferred so far
2001 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
2002 *
2003 * This is a helper for drivers to collect the end of the TX timestamp for
2004 * the requested byte from the SPI transfer. Can be called with an arbitrary
2005 * frequency: only the first call where @tx exceeds or is equal to the
2006 * requested word will be timestamped.
2007 */
2008void spi_take_timestamp_post(struct spi_controller *ctlr,
2009 struct spi_transfer *xfer,
2010 size_t progress, bool irqs_off)
2011{
2012 if (!xfer->ptp_sts)
2013 return;
2014
2015 if (xfer->timestamped)
2016 return;
2017
2018 if (progress < xfer->ptp_sts_word_post)
2019 return;
2020
2021 ptp_read_system_postts(xfer->ptp_sts);
2022
2023 if (irqs_off) {
2024 local_irq_restore(ctlr->irq_flags);
2025 preempt_enable();
2026 }
2027
2028 /* Capture the resolution of the timestamp */
2029 xfer->ptp_sts_word_post = progress;
2030
2031 xfer->timestamped = 1;
2032}
2033EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
2034
2035/**
2036 * spi_set_thread_rt - set the controller to pump at realtime priority
2037 * @ctlr: controller to boost priority of
2038 *
2039 * This can be called because the controller requested realtime priority
2040 * (by setting the ->rt value before calling spi_register_controller()) or
2041 * because a device on the bus said that its transfers needed realtime
2042 * priority.
2043 *
2044 * NOTE: at the moment if any device on a bus says it needs realtime then
2045 * the thread will be at realtime priority for all transfers on that
2046 * controller. If this eventually becomes a problem we may see if we can
2047 * find a way to boost the priority only temporarily during relevant
2048 * transfers.
2049 */
2050static void spi_set_thread_rt(struct spi_controller *ctlr)
2051{
2052 dev_info(&ctlr->dev,
2053 "will run message pump with realtime priority\n");
2054 sched_set_fifo(ctlr->kworker->task);
2055}
2056
2057static int spi_init_queue(struct spi_controller *ctlr)
2058{
2059 ctlr->running = false;
2060 ctlr->busy = false;
2061 ctlr->queue_empty = true;
2062
2063 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
2064 if (IS_ERR(ctlr->kworker)) {
2065 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
2066 return PTR_ERR(ctlr->kworker);
2067 }
2068
2069 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
2070
2071 /*
2072 * Controller config will indicate if this controller should run the
2073 * message pump with high (realtime) priority to reduce the transfer
2074 * latency on the bus by minimising the delay between a transfer
2075 * request and the scheduling of the message pump thread. Without this
2076 * setting the message pump thread will remain at default priority.
2077 */
2078 if (ctlr->rt)
2079 spi_set_thread_rt(ctlr);
2080
2081 return 0;
2082}
2083
2084/**
2085 * spi_get_next_queued_message() - called by driver to check for queued
2086 * messages
2087 * @ctlr: the controller to check for queued messages
2088 *
2089 * If there are more messages in the queue, the next message is returned from
2090 * this call.
2091 *
2092 * Return: the next message in the queue, else NULL if the queue is empty.
2093 */
2094struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
2095{
2096 struct spi_message *next;
2097 unsigned long flags;
2098
2099 /* Get a pointer to the next message, if any */
2100 spin_lock_irqsave(&ctlr->queue_lock, flags);
2101 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
2102 queue);
2103 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2104
2105 return next;
2106}
2107EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
2108
2109/*
2110 * __spi_unoptimize_message - shared implementation of spi_unoptimize_message()
2111 * and spi_maybe_unoptimize_message()
2112 * @msg: the message to unoptimize
2113 *
2114 * Peripheral drivers should use spi_unoptimize_message() and callers inside
2115 * core should use spi_maybe_unoptimize_message() rather than calling this
2116 * function directly.
2117 *
2118 * It is not valid to call this on a message that is not currently optimized.
2119 */
2120static void __spi_unoptimize_message(struct spi_message *msg)
2121{
2122 struct spi_controller *ctlr = msg->spi->controller;
2123
2124 if (ctlr->unoptimize_message)
2125 ctlr->unoptimize_message(msg);
2126
2127 spi_res_release(ctlr, msg);
2128
2129 msg->optimized = false;
2130 msg->opt_state = NULL;
2131}
2132
2133/*
2134 * spi_maybe_unoptimize_message - unoptimize msg not managed by a peripheral
2135 * @msg: the message to unoptimize
2136 *
2137 * This function is used to unoptimize a message if and only if it was
2138 * optimized by the core (via spi_maybe_optimize_message()).
2139 */
2140static void spi_maybe_unoptimize_message(struct spi_message *msg)
2141{
2142 if (!msg->pre_optimized && msg->optimized &&
2143 !msg->spi->controller->defer_optimize_message)
2144 __spi_unoptimize_message(msg);
2145}
2146
2147/**
2148 * spi_finalize_current_message() - the current message is complete
2149 * @ctlr: the controller to return the message to
2150 *
2151 * Called by the driver to notify the core that the message in the front of the
2152 * queue is complete and can be removed from the queue.
2153 */
2154void spi_finalize_current_message(struct spi_controller *ctlr)
2155{
2156 struct spi_transfer *xfer;
2157 struct spi_message *mesg;
2158 int ret;
2159
2160 mesg = ctlr->cur_msg;
2161
2162 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
2163 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
2164 ptp_read_system_postts(xfer->ptp_sts);
2165 xfer->ptp_sts_word_post = xfer->len;
2166 }
2167 }
2168
2169 if (unlikely(ctlr->ptp_sts_supported))
2170 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
2171 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
2172
2173 spi_unmap_msg(ctlr, mesg);
2174
2175 if (mesg->prepared && ctlr->unprepare_message) {
2176 ret = ctlr->unprepare_message(ctlr, mesg);
2177 if (ret) {
2178 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
2179 ret);
2180 }
2181 }
2182
2183 mesg->prepared = false;
2184
2185 spi_maybe_unoptimize_message(mesg);
2186
2187 WRITE_ONCE(ctlr->cur_msg_incomplete, false);
2188 smp_mb(); /* See __spi_pump_transfer_message()... */
2189 if (READ_ONCE(ctlr->cur_msg_need_completion))
2190 complete(&ctlr->cur_msg_completion);
2191
2192 trace_spi_message_done(mesg);
2193
2194 mesg->state = NULL;
2195 if (mesg->complete)
2196 mesg->complete(mesg->context);
2197}
2198EXPORT_SYMBOL_GPL(spi_finalize_current_message);
2199
2200static int spi_start_queue(struct spi_controller *ctlr)
2201{
2202 unsigned long flags;
2203
2204 spin_lock_irqsave(&ctlr->queue_lock, flags);
2205
2206 if (ctlr->running || ctlr->busy) {
2207 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2208 return -EBUSY;
2209 }
2210
2211 ctlr->running = true;
2212 ctlr->cur_msg = NULL;
2213 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2214
2215 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2216
2217 return 0;
2218}
2219
2220static int spi_stop_queue(struct spi_controller *ctlr)
2221{
2222 unsigned int limit = 500;
2223 unsigned long flags;
2224
2225 /*
2226 * This is a bit lame, but is optimized for the common execution path.
2227 * A wait_queue on the ctlr->busy could be used, but then the common
2228 * execution path (pump_messages) would be required to call wake_up or
2229 * friends on every SPI message. Do this instead.
2230 */
2231 do {
2232 spin_lock_irqsave(&ctlr->queue_lock, flags);
2233 if (list_empty(&ctlr->queue) && !ctlr->busy) {
2234 ctlr->running = false;
2235 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2236 return 0;
2237 }
2238 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2239 usleep_range(10000, 11000);
2240 } while (--limit);
2241
2242 return -EBUSY;
2243}
2244
2245static int spi_destroy_queue(struct spi_controller *ctlr)
2246{
2247 int ret;
2248
2249 ret = spi_stop_queue(ctlr);
2250
2251 /*
2252 * kthread_flush_worker will block until all work is done.
2253 * If the reason that stop_queue timed out is that the work will never
2254 * finish, then it does no good to call flush/stop thread, so
2255 * return anyway.
2256 */
2257 if (ret) {
2258 dev_err(&ctlr->dev, "problem destroying queue\n");
2259 return ret;
2260 }
2261
2262 kthread_destroy_worker(ctlr->kworker);
2263
2264 return 0;
2265}
2266
2267static int __spi_queued_transfer(struct spi_device *spi,
2268 struct spi_message *msg,
2269 bool need_pump)
2270{
2271 struct spi_controller *ctlr = spi->controller;
2272 unsigned long flags;
2273
2274 spin_lock_irqsave(&ctlr->queue_lock, flags);
2275
2276 if (!ctlr->running) {
2277 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2278 return -ESHUTDOWN;
2279 }
2280 msg->actual_length = 0;
2281 msg->status = -EINPROGRESS;
2282
2283 list_add_tail(&msg->queue, &ctlr->queue);
2284 ctlr->queue_empty = false;
2285 if (!ctlr->busy && need_pump)
2286 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
2287
2288 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
2289 return 0;
2290}
2291
2292/**
2293 * spi_queued_transfer - transfer function for queued transfers
2294 * @spi: SPI device which is requesting transfer
2295 * @msg: SPI message which is to handled is queued to driver queue
2296 *
2297 * Return: zero on success, else a negative error code.
2298 */
2299static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
2300{
2301 return __spi_queued_transfer(spi, msg, true);
2302}
2303
2304static int spi_controller_initialize_queue(struct spi_controller *ctlr)
2305{
2306 int ret;
2307
2308 ctlr->transfer = spi_queued_transfer;
2309 if (!ctlr->transfer_one_message)
2310 ctlr->transfer_one_message = spi_transfer_one_message;
2311
2312 /* Initialize and start queue */
2313 ret = spi_init_queue(ctlr);
2314 if (ret) {
2315 dev_err(&ctlr->dev, "problem initializing queue\n");
2316 goto err_init_queue;
2317 }
2318 ctlr->queued = true;
2319 ret = spi_start_queue(ctlr);
2320 if (ret) {
2321 dev_err(&ctlr->dev, "problem starting queue\n");
2322 goto err_start_queue;
2323 }
2324
2325 return 0;
2326
2327err_start_queue:
2328 spi_destroy_queue(ctlr);
2329err_init_queue:
2330 return ret;
2331}
2332
2333/**
2334 * spi_flush_queue - Send all pending messages in the queue from the callers'
2335 * context
2336 * @ctlr: controller to process queue for
2337 *
2338 * This should be used when one wants to ensure all pending messages have been
2339 * sent before doing something. Is used by the spi-mem code to make sure SPI
2340 * memory operations do not preempt regular SPI transfers that have been queued
2341 * before the spi-mem operation.
2342 */
2343void spi_flush_queue(struct spi_controller *ctlr)
2344{
2345 if (ctlr->transfer == spi_queued_transfer)
2346 __spi_pump_messages(ctlr, false);
2347}
2348
2349/*-------------------------------------------------------------------------*/
2350
2351#if defined(CONFIG_OF)
2352static void of_spi_parse_dt_cs_delay(struct device_node *nc,
2353 struct spi_delay *delay, const char *prop)
2354{
2355 u32 value;
2356
2357 if (!of_property_read_u32(nc, prop, &value)) {
2358 if (value > U16_MAX) {
2359 delay->value = DIV_ROUND_UP(value, 1000);
2360 delay->unit = SPI_DELAY_UNIT_USECS;
2361 } else {
2362 delay->value = value;
2363 delay->unit = SPI_DELAY_UNIT_NSECS;
2364 }
2365 }
2366}
2367
2368static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
2369 struct device_node *nc)
2370{
2371 u32 value, cs[SPI_CS_CNT_MAX];
2372 int rc, idx;
2373
2374 /* Mode (clock phase/polarity/etc.) */
2375 if (of_property_read_bool(nc, "spi-cpha"))
2376 spi->mode |= SPI_CPHA;
2377 if (of_property_read_bool(nc, "spi-cpol"))
2378 spi->mode |= SPI_CPOL;
2379 if (of_property_read_bool(nc, "spi-3wire"))
2380 spi->mode |= SPI_3WIRE;
2381 if (of_property_read_bool(nc, "spi-lsb-first"))
2382 spi->mode |= SPI_LSB_FIRST;
2383 if (of_property_read_bool(nc, "spi-cs-high"))
2384 spi->mode |= SPI_CS_HIGH;
2385
2386 /* Device DUAL/QUAD mode */
2387 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2388 switch (value) {
2389 case 0:
2390 spi->mode |= SPI_NO_TX;
2391 break;
2392 case 1:
2393 break;
2394 case 2:
2395 spi->mode |= SPI_TX_DUAL;
2396 break;
2397 case 4:
2398 spi->mode |= SPI_TX_QUAD;
2399 break;
2400 case 8:
2401 spi->mode |= SPI_TX_OCTAL;
2402 break;
2403 default:
2404 dev_warn(&ctlr->dev,
2405 "spi-tx-bus-width %d not supported\n",
2406 value);
2407 break;
2408 }
2409 }
2410
2411 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2412 switch (value) {
2413 case 0:
2414 spi->mode |= SPI_NO_RX;
2415 break;
2416 case 1:
2417 break;
2418 case 2:
2419 spi->mode |= SPI_RX_DUAL;
2420 break;
2421 case 4:
2422 spi->mode |= SPI_RX_QUAD;
2423 break;
2424 case 8:
2425 spi->mode |= SPI_RX_OCTAL;
2426 break;
2427 default:
2428 dev_warn(&ctlr->dev,
2429 "spi-rx-bus-width %d not supported\n",
2430 value);
2431 break;
2432 }
2433 }
2434
2435 if (spi_controller_is_target(ctlr)) {
2436 if (!of_node_name_eq(nc, "slave")) {
2437 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2438 nc);
2439 return -EINVAL;
2440 }
2441 return 0;
2442 }
2443
2444 if (ctlr->num_chipselect > SPI_CS_CNT_MAX) {
2445 dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n");
2446 return -EINVAL;
2447 }
2448
2449 spi_set_all_cs_unused(spi);
2450
2451 /* Device address */
2452 rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
2453 SPI_CS_CNT_MAX);
2454 if (rc < 0) {
2455 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2456 nc, rc);
2457 return rc;
2458 }
2459 if (rc > ctlr->num_chipselect) {
2460 dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n",
2461 nc, rc);
2462 return rc;
2463 }
2464 if ((of_property_present(nc, "parallel-memories")) &&
2465 (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) {
2466 dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
2467 return -EINVAL;
2468 }
2469 for (idx = 0; idx < rc; idx++)
2470 spi_set_chipselect(spi, idx, cs[idx]);
2471
2472 /*
2473 * By default spi->chip_select[0] will hold the physical CS number,
2474 * so set bit 0 in spi->cs_index_mask.
2475 */
2476 spi->cs_index_mask = BIT(0);
2477
2478 /* Device speed */
2479 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2480 spi->max_speed_hz = value;
2481
2482 /* Device CS delays */
2483 of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns");
2484 of_spi_parse_dt_cs_delay(nc, &spi->cs_hold, "spi-cs-hold-delay-ns");
2485 of_spi_parse_dt_cs_delay(nc, &spi->cs_inactive, "spi-cs-inactive-delay-ns");
2486
2487 return 0;
2488}
2489
2490static struct spi_device *
2491of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2492{
2493 struct spi_device *spi;
2494 int rc;
2495
2496 /* Alloc an spi_device */
2497 spi = spi_alloc_device(ctlr);
2498 if (!spi) {
2499 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2500 rc = -ENOMEM;
2501 goto err_out;
2502 }
2503
2504 /* Select device driver */
2505 rc = of_alias_from_compatible(nc, spi->modalias,
2506 sizeof(spi->modalias));
2507 if (rc < 0) {
2508 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2509 goto err_out;
2510 }
2511
2512 rc = of_spi_parse_dt(ctlr, spi, nc);
2513 if (rc)
2514 goto err_out;
2515
2516 /* Store a pointer to the node in the device structure */
2517 of_node_get(nc);
2518
2519 device_set_node(&spi->dev, of_fwnode_handle(nc));
2520
2521 /* Register the new device */
2522 rc = spi_add_device(spi);
2523 if (rc) {
2524 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2525 goto err_of_node_put;
2526 }
2527
2528 return spi;
2529
2530err_of_node_put:
2531 of_node_put(nc);
2532err_out:
2533 spi_dev_put(spi);
2534 return ERR_PTR(rc);
2535}
2536
2537/**
2538 * of_register_spi_devices() - Register child devices onto the SPI bus
2539 * @ctlr: Pointer to spi_controller device
2540 *
2541 * Registers an spi_device for each child node of controller node which
2542 * represents a valid SPI slave.
2543 */
2544static void of_register_spi_devices(struct spi_controller *ctlr)
2545{
2546 struct spi_device *spi;
2547 struct device_node *nc;
2548
2549 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2550 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2551 continue;
2552 spi = of_register_spi_device(ctlr, nc);
2553 if (IS_ERR(spi)) {
2554 dev_warn(&ctlr->dev,
2555 "Failed to create SPI device for %pOF\n", nc);
2556 of_node_clear_flag(nc, OF_POPULATED);
2557 }
2558 }
2559}
2560#else
2561static void of_register_spi_devices(struct spi_controller *ctlr) { }
2562#endif
2563
2564/**
2565 * spi_new_ancillary_device() - Register ancillary SPI device
2566 * @spi: Pointer to the main SPI device registering the ancillary device
2567 * @chip_select: Chip Select of the ancillary device
2568 *
2569 * Register an ancillary SPI device; for example some chips have a chip-select
2570 * for normal device usage and another one for setup/firmware upload.
2571 *
2572 * This may only be called from main SPI device's probe routine.
2573 *
2574 * Return: 0 on success; negative errno on failure
2575 */
2576struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2577 u8 chip_select)
2578{
2579 struct spi_controller *ctlr = spi->controller;
2580 struct spi_device *ancillary;
2581 int rc;
2582
2583 /* Alloc an spi_device */
2584 ancillary = spi_alloc_device(ctlr);
2585 if (!ancillary) {
2586 rc = -ENOMEM;
2587 goto err_out;
2588 }
2589
2590 strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2591
2592 /* Use provided chip-select for ancillary device */
2593 spi_set_all_cs_unused(ancillary);
2594 spi_set_chipselect(ancillary, 0, chip_select);
2595
2596 /* Take over SPI mode/speed from SPI main device */
2597 ancillary->max_speed_hz = spi->max_speed_hz;
2598 ancillary->mode = spi->mode;
2599 /*
2600 * By default spi->chip_select[0] will hold the physical CS number,
2601 * so set bit 0 in spi->cs_index_mask.
2602 */
2603 ancillary->cs_index_mask = BIT(0);
2604
2605 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
2606
2607 /* Register the new device */
2608 rc = __spi_add_device(ancillary);
2609 if (rc) {
2610 dev_err(&spi->dev, "failed to register ancillary device\n");
2611 goto err_out;
2612 }
2613
2614 return ancillary;
2615
2616err_out:
2617 spi_dev_put(ancillary);
2618 return ERR_PTR(rc);
2619}
2620EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2621
2622#ifdef CONFIG_ACPI
2623struct acpi_spi_lookup {
2624 struct spi_controller *ctlr;
2625 u32 max_speed_hz;
2626 u32 mode;
2627 int irq;
2628 u8 bits_per_word;
2629 u8 chip_select;
2630 int n;
2631 int index;
2632};
2633
2634static int acpi_spi_count(struct acpi_resource *ares, void *data)
2635{
2636 struct acpi_resource_spi_serialbus *sb;
2637 int *count = data;
2638
2639 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
2640 return 1;
2641
2642 sb = &ares->data.spi_serial_bus;
2643 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
2644 return 1;
2645
2646 *count = *count + 1;
2647
2648 return 1;
2649}
2650
2651/**
2652 * acpi_spi_count_resources - Count the number of SpiSerialBus resources
2653 * @adev: ACPI device
2654 *
2655 * Return: the number of SpiSerialBus resources in the ACPI-device's
2656 * resource-list; or a negative error code.
2657 */
2658int acpi_spi_count_resources(struct acpi_device *adev)
2659{
2660 LIST_HEAD(r);
2661 int count = 0;
2662 int ret;
2663
2664 ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
2665 if (ret < 0)
2666 return ret;
2667
2668 acpi_dev_free_resource_list(&r);
2669
2670 return count;
2671}
2672EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
2673
2674static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2675 struct acpi_spi_lookup *lookup)
2676{
2677 const union acpi_object *obj;
2678
2679 if (!x86_apple_machine)
2680 return;
2681
2682 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2683 && obj->buffer.length >= 4)
2684 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2685
2686 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2687 && obj->buffer.length == 8)
2688 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2689
2690 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2691 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2692 lookup->mode |= SPI_LSB_FIRST;
2693
2694 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2695 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2696 lookup->mode |= SPI_CPOL;
2697
2698 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2699 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2700 lookup->mode |= SPI_CPHA;
2701}
2702
2703static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2704{
2705 struct acpi_spi_lookup *lookup = data;
2706 struct spi_controller *ctlr = lookup->ctlr;
2707
2708 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2709 struct acpi_resource_spi_serialbus *sb;
2710 acpi_handle parent_handle;
2711 acpi_status status;
2712
2713 sb = &ares->data.spi_serial_bus;
2714 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2715
2716 if (lookup->index != -1 && lookup->n++ != lookup->index)
2717 return 1;
2718
2719 status = acpi_get_handle(NULL,
2720 sb->resource_source.string_ptr,
2721 &parent_handle);
2722
2723 if (ACPI_FAILURE(status))
2724 return -ENODEV;
2725
2726 if (ctlr) {
2727 if (!device_match_acpi_handle(ctlr->dev.parent, parent_handle))
2728 return -ENODEV;
2729 } else {
2730 struct acpi_device *adev;
2731
2732 adev = acpi_fetch_acpi_dev(parent_handle);
2733 if (!adev)
2734 return -ENODEV;
2735
2736 ctlr = acpi_spi_find_controller_by_adev(adev);
2737 if (!ctlr)
2738 return -EPROBE_DEFER;
2739
2740 lookup->ctlr = ctlr;
2741 }
2742
2743 /*
2744 * ACPI DeviceSelection numbering is handled by the
2745 * host controller driver in Windows and can vary
2746 * from driver to driver. In Linux we always expect
2747 * 0 .. max - 1 so we need to ask the driver to
2748 * translate between the two schemes.
2749 */
2750 if (ctlr->fw_translate_cs) {
2751 int cs = ctlr->fw_translate_cs(ctlr,
2752 sb->device_selection);
2753 if (cs < 0)
2754 return cs;
2755 lookup->chip_select = cs;
2756 } else {
2757 lookup->chip_select = sb->device_selection;
2758 }
2759
2760 lookup->max_speed_hz = sb->connection_speed;
2761 lookup->bits_per_word = sb->data_bit_length;
2762
2763 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2764 lookup->mode |= SPI_CPHA;
2765 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2766 lookup->mode |= SPI_CPOL;
2767 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2768 lookup->mode |= SPI_CS_HIGH;
2769 }
2770 } else if (lookup->irq < 0) {
2771 struct resource r;
2772
2773 if (acpi_dev_resource_interrupt(ares, 0, &r))
2774 lookup->irq = r.start;
2775 }
2776
2777 /* Always tell the ACPI core to skip this resource */
2778 return 1;
2779}
2780
2781/**
2782 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information
2783 * @ctlr: controller to which the spi device belongs
2784 * @adev: ACPI Device for the spi device
2785 * @index: Index of the spi resource inside the ACPI Node
2786 *
2787 * This should be used to allocate a new SPI device from and ACPI Device node.
2788 * The caller is responsible for calling spi_add_device to register the SPI device.
2789 *
2790 * If ctlr is set to NULL, the Controller for the SPI device will be looked up
2791 * using the resource.
2792 * If index is set to -1, index is not used.
2793 * Note: If index is -1, ctlr must be set.
2794 *
2795 * Return: a pointer to the new device, or ERR_PTR on error.
2796 */
2797struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
2798 struct acpi_device *adev,
2799 int index)
2800{
2801 acpi_handle parent_handle = NULL;
2802 struct list_head resource_list;
2803 struct acpi_spi_lookup lookup = {};
2804 struct spi_device *spi;
2805 int ret;
2806
2807 if (!ctlr && index == -1)
2808 return ERR_PTR(-EINVAL);
2809
2810 lookup.ctlr = ctlr;
2811 lookup.irq = -1;
2812 lookup.index = index;
2813 lookup.n = 0;
2814
2815 INIT_LIST_HEAD(&resource_list);
2816 ret = acpi_dev_get_resources(adev, &resource_list,
2817 acpi_spi_add_resource, &lookup);
2818 acpi_dev_free_resource_list(&resource_list);
2819
2820 if (ret < 0)
2821 /* Found SPI in _CRS but it points to another controller */
2822 return ERR_PTR(ret);
2823
2824 if (!lookup.max_speed_hz &&
2825 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2826 device_match_acpi_handle(lookup.ctlr->dev.parent, parent_handle)) {
2827 /* Apple does not use _CRS but nested devices for SPI slaves */
2828 acpi_spi_parse_apple_properties(adev, &lookup);
2829 }
2830
2831 if (!lookup.max_speed_hz)
2832 return ERR_PTR(-ENODEV);
2833
2834 spi = spi_alloc_device(lookup.ctlr);
2835 if (!spi) {
2836 dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",
2837 dev_name(&adev->dev));
2838 return ERR_PTR(-ENOMEM);
2839 }
2840
2841 spi_set_all_cs_unused(spi);
2842 spi_set_chipselect(spi, 0, lookup.chip_select);
2843
2844 ACPI_COMPANION_SET(&spi->dev, adev);
2845 spi->max_speed_hz = lookup.max_speed_hz;
2846 spi->mode |= lookup.mode;
2847 spi->irq = lookup.irq;
2848 spi->bits_per_word = lookup.bits_per_word;
2849 /*
2850 * By default spi->chip_select[0] will hold the physical CS number,
2851 * so set bit 0 in spi->cs_index_mask.
2852 */
2853 spi->cs_index_mask = BIT(0);
2854
2855 return spi;
2856}
2857EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);
2858
2859static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2860 struct acpi_device *adev)
2861{
2862 struct spi_device *spi;
2863
2864 if (acpi_bus_get_status(adev) || !adev->status.present ||
2865 acpi_device_enumerated(adev))
2866 return AE_OK;
2867
2868 spi = acpi_spi_device_alloc(ctlr, adev, -1);
2869 if (IS_ERR(spi)) {
2870 if (PTR_ERR(spi) == -ENOMEM)
2871 return AE_NO_MEMORY;
2872 else
2873 return AE_OK;
2874 }
2875
2876 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2877 sizeof(spi->modalias));
2878
2879 acpi_device_set_enumerated(adev);
2880
2881 adev->power.flags.ignore_parent = true;
2882 if (spi_add_device(spi)) {
2883 adev->power.flags.ignore_parent = false;
2884 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2885 dev_name(&adev->dev));
2886 spi_dev_put(spi);
2887 }
2888
2889 return AE_OK;
2890}
2891
2892static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2893 void *data, void **return_value)
2894{
2895 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
2896 struct spi_controller *ctlr = data;
2897
2898 if (!adev)
2899 return AE_OK;
2900
2901 return acpi_register_spi_device(ctlr, adev);
2902}
2903
2904#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2905
2906static void acpi_register_spi_devices(struct spi_controller *ctlr)
2907{
2908 acpi_status status;
2909 acpi_handle handle;
2910
2911 handle = ACPI_HANDLE(ctlr->dev.parent);
2912 if (!handle)
2913 return;
2914
2915 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2916 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2917 acpi_spi_add_device, NULL, ctlr, NULL);
2918 if (ACPI_FAILURE(status))
2919 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2920}
2921#else
2922static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2923#endif /* CONFIG_ACPI */
2924
2925static void spi_controller_release(struct device *dev)
2926{
2927 struct spi_controller *ctlr;
2928
2929 ctlr = container_of(dev, struct spi_controller, dev);
2930 kfree(ctlr);
2931}
2932
2933static const struct class spi_master_class = {
2934 .name = "spi_master",
2935 .dev_release = spi_controller_release,
2936 .dev_groups = spi_master_groups,
2937};
2938
2939#ifdef CONFIG_SPI_SLAVE
2940/**
2941 * spi_target_abort - abort the ongoing transfer request on an SPI slave
2942 * controller
2943 * @spi: device used for the current transfer
2944 */
2945int spi_target_abort(struct spi_device *spi)
2946{
2947 struct spi_controller *ctlr = spi->controller;
2948
2949 if (spi_controller_is_target(ctlr) && ctlr->target_abort)
2950 return ctlr->target_abort(ctlr);
2951
2952 return -ENOTSUPP;
2953}
2954EXPORT_SYMBOL_GPL(spi_target_abort);
2955
2956static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2957 char *buf)
2958{
2959 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2960 dev);
2961 struct device *child;
2962
2963 child = device_find_any_child(&ctlr->dev);
2964 return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);
2965}
2966
2967static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2968 const char *buf, size_t count)
2969{
2970 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2971 dev);
2972 struct spi_device *spi;
2973 struct device *child;
2974 char name[32];
2975 int rc;
2976
2977 rc = sscanf(buf, "%31s", name);
2978 if (rc != 1 || !name[0])
2979 return -EINVAL;
2980
2981 child = device_find_any_child(&ctlr->dev);
2982 if (child) {
2983 /* Remove registered slave */
2984 device_unregister(child);
2985 put_device(child);
2986 }
2987
2988 if (strcmp(name, "(null)")) {
2989 /* Register new slave */
2990 spi = spi_alloc_device(ctlr);
2991 if (!spi)
2992 return -ENOMEM;
2993
2994 strscpy(spi->modalias, name, sizeof(spi->modalias));
2995
2996 rc = spi_add_device(spi);
2997 if (rc) {
2998 spi_dev_put(spi);
2999 return rc;
3000 }
3001 }
3002
3003 return count;
3004}
3005
3006static DEVICE_ATTR_RW(slave);
3007
3008static struct attribute *spi_slave_attrs[] = {
3009 &dev_attr_slave.attr,
3010 NULL,
3011};
3012
3013static const struct attribute_group spi_slave_group = {
3014 .attrs = spi_slave_attrs,
3015};
3016
3017static const struct attribute_group *spi_slave_groups[] = {
3018 &spi_controller_statistics_group,
3019 &spi_slave_group,
3020 NULL,
3021};
3022
3023static const struct class spi_slave_class = {
3024 .name = "spi_slave",
3025 .dev_release = spi_controller_release,
3026 .dev_groups = spi_slave_groups,
3027};
3028#else
3029extern struct class spi_slave_class; /* dummy */
3030#endif
3031
3032/**
3033 * __spi_alloc_controller - allocate an SPI master or slave controller
3034 * @dev: the controller, possibly using the platform_bus
3035 * @size: how much zeroed driver-private data to allocate; the pointer to this
3036 * memory is in the driver_data field of the returned device, accessible
3037 * with spi_controller_get_devdata(); the memory is cacheline aligned;
3038 * drivers granting DMA access to portions of their private data need to
3039 * round up @size using ALIGN(size, dma_get_cache_alignment()).
3040 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
3041 * slave (true) controller
3042 * Context: can sleep
3043 *
3044 * This call is used only by SPI controller drivers, which are the
3045 * only ones directly touching chip registers. It's how they allocate
3046 * an spi_controller structure, prior to calling spi_register_controller().
3047 *
3048 * This must be called from context that can sleep.
3049 *
3050 * The caller is responsible for assigning the bus number and initializing the
3051 * controller's methods before calling spi_register_controller(); and (after
3052 * errors adding the device) calling spi_controller_put() to prevent a memory
3053 * leak.
3054 *
3055 * Return: the SPI controller structure on success, else NULL.
3056 */
3057struct spi_controller *__spi_alloc_controller(struct device *dev,
3058 unsigned int size, bool slave)
3059{
3060 struct spi_controller *ctlr;
3061 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
3062
3063 if (!dev)
3064 return NULL;
3065
3066 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
3067 if (!ctlr)
3068 return NULL;
3069
3070 device_initialize(&ctlr->dev);
3071 INIT_LIST_HEAD(&ctlr->queue);
3072 spin_lock_init(&ctlr->queue_lock);
3073 spin_lock_init(&ctlr->bus_lock_spinlock);
3074 mutex_init(&ctlr->bus_lock_mutex);
3075 mutex_init(&ctlr->io_mutex);
3076 mutex_init(&ctlr->add_lock);
3077 ctlr->bus_num = -1;
3078 ctlr->num_chipselect = 1;
3079 ctlr->slave = slave;
3080 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
3081 ctlr->dev.class = &spi_slave_class;
3082 else
3083 ctlr->dev.class = &spi_master_class;
3084 ctlr->dev.parent = dev;
3085 pm_suspend_ignore_children(&ctlr->dev, true);
3086 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
3087
3088 return ctlr;
3089}
3090EXPORT_SYMBOL_GPL(__spi_alloc_controller);
3091
3092static void devm_spi_release_controller(struct device *dev, void *ctlr)
3093{
3094 spi_controller_put(*(struct spi_controller **)ctlr);
3095}
3096
3097/**
3098 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
3099 * @dev: physical device of SPI controller
3100 * @size: how much zeroed driver-private data to allocate
3101 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
3102 * Context: can sleep
3103 *
3104 * Allocate an SPI controller and automatically release a reference on it
3105 * when @dev is unbound from its driver. Drivers are thus relieved from
3106 * having to call spi_controller_put().
3107 *
3108 * The arguments to this function are identical to __spi_alloc_controller().
3109 *
3110 * Return: the SPI controller structure on success, else NULL.
3111 */
3112struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
3113 unsigned int size,
3114 bool slave)
3115{
3116 struct spi_controller **ptr, *ctlr;
3117
3118 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
3119 GFP_KERNEL);
3120 if (!ptr)
3121 return NULL;
3122
3123 ctlr = __spi_alloc_controller(dev, size, slave);
3124 if (ctlr) {
3125 ctlr->devm_allocated = true;
3126 *ptr = ctlr;
3127 devres_add(dev, ptr);
3128 } else {
3129 devres_free(ptr);
3130 }
3131
3132 return ctlr;
3133}
3134EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
3135
3136/**
3137 * spi_get_gpio_descs() - grab chip select GPIOs for the master
3138 * @ctlr: The SPI master to grab GPIO descriptors for
3139 */
3140static int spi_get_gpio_descs(struct spi_controller *ctlr)
3141{
3142 int nb, i;
3143 struct gpio_desc **cs;
3144 struct device *dev = &ctlr->dev;
3145 unsigned long native_cs_mask = 0;
3146 unsigned int num_cs_gpios = 0;
3147
3148 nb = gpiod_count(dev, "cs");
3149 if (nb < 0) {
3150 /* No GPIOs at all is fine, else return the error */
3151 if (nb == -ENOENT)
3152 return 0;
3153 return nb;
3154 }
3155
3156 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
3157
3158 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
3159 GFP_KERNEL);
3160 if (!cs)
3161 return -ENOMEM;
3162 ctlr->cs_gpiods = cs;
3163
3164 for (i = 0; i < nb; i++) {
3165 /*
3166 * Most chipselects are active low, the inverted
3167 * semantics are handled by special quirks in gpiolib,
3168 * so initializing them GPIOD_OUT_LOW here means
3169 * "unasserted", in most cases this will drive the physical
3170 * line high.
3171 */
3172 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
3173 GPIOD_OUT_LOW);
3174 if (IS_ERR(cs[i]))
3175 return PTR_ERR(cs[i]);
3176
3177 if (cs[i]) {
3178 /*
3179 * If we find a CS GPIO, name it after the device and
3180 * chip select line.
3181 */
3182 char *gpioname;
3183
3184 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
3185 dev_name(dev), i);
3186 if (!gpioname)
3187 return -ENOMEM;
3188 gpiod_set_consumer_name(cs[i], gpioname);
3189 num_cs_gpios++;
3190 continue;
3191 }
3192
3193 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
3194 dev_err(dev, "Invalid native chip select %d\n", i);
3195 return -EINVAL;
3196 }
3197 native_cs_mask |= BIT(i);
3198 }
3199
3200 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
3201
3202 if ((ctlr->flags & SPI_CONTROLLER_GPIO_SS) && num_cs_gpios &&
3203 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
3204 dev_err(dev, "No unused native chip select available\n");
3205 return -EINVAL;
3206 }
3207
3208 return 0;
3209}
3210
3211static int spi_controller_check_ops(struct spi_controller *ctlr)
3212{
3213 /*
3214 * The controller may implement only the high-level SPI-memory like
3215 * operations if it does not support regular SPI transfers, and this is
3216 * valid use case.
3217 * If ->mem_ops or ->mem_ops->exec_op is NULL, we request that at least
3218 * one of the ->transfer_xxx() method be implemented.
3219 */
3220 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
3221 if (!ctlr->transfer && !ctlr->transfer_one &&
3222 !ctlr->transfer_one_message) {
3223 return -EINVAL;
3224 }
3225 }
3226
3227 return 0;
3228}
3229
3230/* Allocate dynamic bus number using Linux idr */
3231static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end)
3232{
3233 int id;
3234
3235 mutex_lock(&board_lock);
3236 id = idr_alloc(&spi_master_idr, ctlr, start, end, GFP_KERNEL);
3237 mutex_unlock(&board_lock);
3238 if (WARN(id < 0, "couldn't get idr"))
3239 return id == -ENOSPC ? -EBUSY : id;
3240 ctlr->bus_num = id;
3241 return 0;
3242}
3243
3244/**
3245 * spi_register_controller - register SPI host or target controller
3246 * @ctlr: initialized controller, originally from spi_alloc_host() or
3247 * spi_alloc_target()
3248 * Context: can sleep
3249 *
3250 * SPI controllers connect to their drivers using some non-SPI bus,
3251 * such as the platform bus. The final stage of probe() in that code
3252 * includes calling spi_register_controller() to hook up to this SPI bus glue.
3253 *
3254 * SPI controllers use board specific (often SOC specific) bus numbers,
3255 * and board-specific addressing for SPI devices combines those numbers
3256 * with chip select numbers. Since SPI does not directly support dynamic
3257 * device identification, boards need configuration tables telling which
3258 * chip is at which address.
3259 *
3260 * This must be called from context that can sleep. It returns zero on
3261 * success, else a negative error code (dropping the controller's refcount).
3262 * After a successful return, the caller is responsible for calling
3263 * spi_unregister_controller().
3264 *
3265 * Return: zero on success, else a negative error code.
3266 */
3267int spi_register_controller(struct spi_controller *ctlr)
3268{
3269 struct device *dev = ctlr->dev.parent;
3270 struct boardinfo *bi;
3271 int first_dynamic;
3272 int status;
3273 int idx;
3274
3275 if (!dev)
3276 return -ENODEV;
3277
3278 /*
3279 * Make sure all necessary hooks are implemented before registering
3280 * the SPI controller.
3281 */
3282 status = spi_controller_check_ops(ctlr);
3283 if (status)
3284 return status;
3285
3286 if (ctlr->bus_num < 0)
3287 ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi");
3288 if (ctlr->bus_num >= 0) {
3289 /* Devices with a fixed bus num must check-in with the num */
3290 status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1);
3291 if (status)
3292 return status;
3293 }
3294 if (ctlr->bus_num < 0) {
3295 first_dynamic = of_alias_get_highest_id("spi");
3296 if (first_dynamic < 0)
3297 first_dynamic = 0;
3298 else
3299 first_dynamic++;
3300
3301 status = spi_controller_id_alloc(ctlr, first_dynamic, 0);
3302 if (status)
3303 return status;
3304 }
3305 ctlr->bus_lock_flag = 0;
3306 init_completion(&ctlr->xfer_completion);
3307 init_completion(&ctlr->cur_msg_completion);
3308 if (!ctlr->max_dma_len)
3309 ctlr->max_dma_len = INT_MAX;
3310
3311 /*
3312 * Register the device, then userspace will see it.
3313 * Registration fails if the bus ID is in use.
3314 */
3315 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
3316
3317 if (!spi_controller_is_target(ctlr) && ctlr->use_gpio_descriptors) {
3318 status = spi_get_gpio_descs(ctlr);
3319 if (status)
3320 goto free_bus_id;
3321 /*
3322 * A controller using GPIO descriptors always
3323 * supports SPI_CS_HIGH if need be.
3324 */
3325 ctlr->mode_bits |= SPI_CS_HIGH;
3326 }
3327
3328 /*
3329 * Even if it's just one always-selected device, there must
3330 * be at least one chipselect.
3331 */
3332 if (!ctlr->num_chipselect) {
3333 status = -EINVAL;
3334 goto free_bus_id;
3335 }
3336
3337 /* Setting last_cs to SPI_INVALID_CS means no chip selected */
3338 for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
3339 ctlr->last_cs[idx] = SPI_INVALID_CS;
3340
3341 status = device_add(&ctlr->dev);
3342 if (status < 0)
3343 goto free_bus_id;
3344 dev_dbg(dev, "registered %s %s\n",
3345 spi_controller_is_target(ctlr) ? "target" : "host",
3346 dev_name(&ctlr->dev));
3347
3348 /*
3349 * If we're using a queued driver, start the queue. Note that we don't
3350 * need the queueing logic if the driver is only supporting high-level
3351 * memory operations.
3352 */
3353 if (ctlr->transfer) {
3354 dev_info(dev, "controller is unqueued, this is deprecated\n");
3355 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
3356 status = spi_controller_initialize_queue(ctlr);
3357 if (status) {
3358 device_del(&ctlr->dev);
3359 goto free_bus_id;
3360 }
3361 }
3362 /* Add statistics */
3363 ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);
3364 if (!ctlr->pcpu_statistics) {
3365 dev_err(dev, "Error allocating per-cpu statistics\n");
3366 status = -ENOMEM;
3367 goto destroy_queue;
3368 }
3369
3370 mutex_lock(&board_lock);
3371 list_add_tail(&ctlr->list, &spi_controller_list);
3372 list_for_each_entry(bi, &board_list, list)
3373 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
3374 mutex_unlock(&board_lock);
3375
3376 /* Register devices from the device tree and ACPI */
3377 of_register_spi_devices(ctlr);
3378 acpi_register_spi_devices(ctlr);
3379 return status;
3380
3381destroy_queue:
3382 spi_destroy_queue(ctlr);
3383free_bus_id:
3384 mutex_lock(&board_lock);
3385 idr_remove(&spi_master_idr, ctlr->bus_num);
3386 mutex_unlock(&board_lock);
3387 return status;
3388}
3389EXPORT_SYMBOL_GPL(spi_register_controller);
3390
3391static void devm_spi_unregister(struct device *dev, void *res)
3392{
3393 spi_unregister_controller(*(struct spi_controller **)res);
3394}
3395
3396/**
3397 * devm_spi_register_controller - register managed SPI host or target
3398 * controller
3399 * @dev: device managing SPI controller
3400 * @ctlr: initialized controller, originally from spi_alloc_host() or
3401 * spi_alloc_target()
3402 * Context: can sleep
3403 *
3404 * Register a SPI device as with spi_register_controller() which will
3405 * automatically be unregistered and freed.
3406 *
3407 * Return: zero on success, else a negative error code.
3408 */
3409int devm_spi_register_controller(struct device *dev,
3410 struct spi_controller *ctlr)
3411{
3412 struct spi_controller **ptr;
3413 int ret;
3414
3415 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
3416 if (!ptr)
3417 return -ENOMEM;
3418
3419 ret = spi_register_controller(ctlr);
3420 if (!ret) {
3421 *ptr = ctlr;
3422 devres_add(dev, ptr);
3423 } else {
3424 devres_free(ptr);
3425 }
3426
3427 return ret;
3428}
3429EXPORT_SYMBOL_GPL(devm_spi_register_controller);
3430
3431static int __unregister(struct device *dev, void *null)
3432{
3433 spi_unregister_device(to_spi_device(dev));
3434 return 0;
3435}
3436
3437/**
3438 * spi_unregister_controller - unregister SPI master or slave controller
3439 * @ctlr: the controller being unregistered
3440 * Context: can sleep
3441 *
3442 * This call is used only by SPI controller drivers, which are the
3443 * only ones directly touching chip registers.
3444 *
3445 * This must be called from context that can sleep.
3446 *
3447 * Note that this function also drops a reference to the controller.
3448 */
3449void spi_unregister_controller(struct spi_controller *ctlr)
3450{
3451 struct spi_controller *found;
3452 int id = ctlr->bus_num;
3453
3454 /* Prevent addition of new devices, unregister existing ones */
3455 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3456 mutex_lock(&ctlr->add_lock);
3457
3458 device_for_each_child(&ctlr->dev, NULL, __unregister);
3459
3460 /* First make sure that this controller was ever added */
3461 mutex_lock(&board_lock);
3462 found = idr_find(&spi_master_idr, id);
3463 mutex_unlock(&board_lock);
3464 if (ctlr->queued) {
3465 if (spi_destroy_queue(ctlr))
3466 dev_err(&ctlr->dev, "queue remove failed\n");
3467 }
3468 mutex_lock(&board_lock);
3469 list_del(&ctlr->list);
3470 mutex_unlock(&board_lock);
3471
3472 device_del(&ctlr->dev);
3473
3474 /* Free bus id */
3475 mutex_lock(&board_lock);
3476 if (found == ctlr)
3477 idr_remove(&spi_master_idr, id);
3478 mutex_unlock(&board_lock);
3479
3480 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
3481 mutex_unlock(&ctlr->add_lock);
3482
3483 /*
3484 * Release the last reference on the controller if its driver
3485 * has not yet been converted to devm_spi_alloc_host/target().
3486 */
3487 if (!ctlr->devm_allocated)
3488 put_device(&ctlr->dev);
3489}
3490EXPORT_SYMBOL_GPL(spi_unregister_controller);
3491
3492static inline int __spi_check_suspended(const struct spi_controller *ctlr)
3493{
3494 return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0;
3495}
3496
3497static inline void __spi_mark_suspended(struct spi_controller *ctlr)
3498{
3499 mutex_lock(&ctlr->bus_lock_mutex);
3500 ctlr->flags |= SPI_CONTROLLER_SUSPENDED;
3501 mutex_unlock(&ctlr->bus_lock_mutex);
3502}
3503
3504static inline void __spi_mark_resumed(struct spi_controller *ctlr)
3505{
3506 mutex_lock(&ctlr->bus_lock_mutex);
3507 ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED;
3508 mutex_unlock(&ctlr->bus_lock_mutex);
3509}
3510
3511int spi_controller_suspend(struct spi_controller *ctlr)
3512{
3513 int ret = 0;
3514
3515 /* Basically no-ops for non-queued controllers */
3516 if (ctlr->queued) {
3517 ret = spi_stop_queue(ctlr);
3518 if (ret)
3519 dev_err(&ctlr->dev, "queue stop failed\n");
3520 }
3521
3522 __spi_mark_suspended(ctlr);
3523 return ret;
3524}
3525EXPORT_SYMBOL_GPL(spi_controller_suspend);
3526
3527int spi_controller_resume(struct spi_controller *ctlr)
3528{
3529 int ret = 0;
3530
3531 __spi_mark_resumed(ctlr);
3532
3533 if (ctlr->queued) {
3534 ret = spi_start_queue(ctlr);
3535 if (ret)
3536 dev_err(&ctlr->dev, "queue restart failed\n");
3537 }
3538 return ret;
3539}
3540EXPORT_SYMBOL_GPL(spi_controller_resume);
3541
3542/*-------------------------------------------------------------------------*/
3543
3544/* Core methods for spi_message alterations */
3545
3546static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3547 struct spi_message *msg,
3548 void *res)
3549{
3550 struct spi_replaced_transfers *rxfer = res;
3551 size_t i;
3552
3553 /* Call extra callback if requested */
3554 if (rxfer->release)
3555 rxfer->release(ctlr, msg, res);
3556
3557 /* Insert replaced transfers back into the message */
3558 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3559
3560 /* Remove the formerly inserted entries */
3561 for (i = 0; i < rxfer->inserted; i++)
3562 list_del(&rxfer->inserted_transfers[i].transfer_list);
3563}
3564
3565/**
3566 * spi_replace_transfers - replace transfers with several transfers
3567 * and register change with spi_message.resources
3568 * @msg: the spi_message we work upon
3569 * @xfer_first: the first spi_transfer we want to replace
3570 * @remove: number of transfers to remove
3571 * @insert: the number of transfers we want to insert instead
3572 * @release: extra release code necessary in some circumstances
3573 * @extradatasize: extra data to allocate (with alignment guarantees
3574 * of struct @spi_transfer)
3575 * @gfp: gfp flags
3576 *
3577 * Returns: pointer to @spi_replaced_transfers,
3578 * PTR_ERR(...) in case of errors.
3579 */
3580static struct spi_replaced_transfers *spi_replace_transfers(
3581 struct spi_message *msg,
3582 struct spi_transfer *xfer_first,
3583 size_t remove,
3584 size_t insert,
3585 spi_replaced_release_t release,
3586 size_t extradatasize,
3587 gfp_t gfp)
3588{
3589 struct spi_replaced_transfers *rxfer;
3590 struct spi_transfer *xfer;
3591 size_t i;
3592
3593 /* Allocate the structure using spi_res */
3594 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3595 struct_size(rxfer, inserted_transfers, insert)
3596 + extradatasize,
3597 gfp);
3598 if (!rxfer)
3599 return ERR_PTR(-ENOMEM);
3600
3601 /* The release code to invoke before running the generic release */
3602 rxfer->release = release;
3603
3604 /* Assign extradata */
3605 if (extradatasize)
3606 rxfer->extradata =
3607 &rxfer->inserted_transfers[insert];
3608
3609 /* Init the replaced_transfers list */
3610 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3611
3612 /*
3613 * Assign the list_entry after which we should reinsert
3614 * the @replaced_transfers - it may be spi_message.messages!
3615 */
3616 rxfer->replaced_after = xfer_first->transfer_list.prev;
3617
3618 /* Remove the requested number of transfers */
3619 for (i = 0; i < remove; i++) {
3620 /*
3621 * If the entry after replaced_after it is msg->transfers
3622 * then we have been requested to remove more transfers
3623 * than are in the list.
3624 */
3625 if (rxfer->replaced_after->next == &msg->transfers) {
3626 dev_err(&msg->spi->dev,
3627 "requested to remove more spi_transfers than are available\n");
3628 /* Insert replaced transfers back into the message */
3629 list_splice(&rxfer->replaced_transfers,
3630 rxfer->replaced_after);
3631
3632 /* Free the spi_replace_transfer structure... */
3633 spi_res_free(rxfer);
3634
3635 /* ...and return with an error */
3636 return ERR_PTR(-EINVAL);
3637 }
3638
3639 /*
3640 * Remove the entry after replaced_after from list of
3641 * transfers and add it to list of replaced_transfers.
3642 */
3643 list_move_tail(rxfer->replaced_after->next,
3644 &rxfer->replaced_transfers);
3645 }
3646
3647 /*
3648 * Create copy of the given xfer with identical settings
3649 * based on the first transfer to get removed.
3650 */
3651 for (i = 0; i < insert; i++) {
3652 /* We need to run in reverse order */
3653 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3654
3655 /* Copy all spi_transfer data */
3656 memcpy(xfer, xfer_first, sizeof(*xfer));
3657
3658 /* Add to list */
3659 list_add(&xfer->transfer_list, rxfer->replaced_after);
3660
3661 /* Clear cs_change and delay for all but the last */
3662 if (i) {
3663 xfer->cs_change = false;
3664 xfer->delay.value = 0;
3665 }
3666 }
3667
3668 /* Set up inserted... */
3669 rxfer->inserted = insert;
3670
3671 /* ...and register it with spi_res/spi_message */
3672 spi_res_add(msg, rxfer);
3673
3674 return rxfer;
3675}
3676
3677static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3678 struct spi_message *msg,
3679 struct spi_transfer **xferp,
3680 size_t maxsize)
3681{
3682 struct spi_transfer *xfer = *xferp, *xfers;
3683 struct spi_replaced_transfers *srt;
3684 size_t offset;
3685 size_t count, i;
3686
3687 /* Calculate how many we have to replace */
3688 count = DIV_ROUND_UP(xfer->len, maxsize);
3689
3690 /* Create replacement */
3691 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, GFP_KERNEL);
3692 if (IS_ERR(srt))
3693 return PTR_ERR(srt);
3694 xfers = srt->inserted_transfers;
3695
3696 /*
3697 * Now handle each of those newly inserted spi_transfers.
3698 * Note that the replacements spi_transfers all are preset
3699 * to the same values as *xferp, so tx_buf, rx_buf and len
3700 * are all identical (as well as most others)
3701 * so we just have to fix up len and the pointers.
3702 */
3703
3704 /*
3705 * The first transfer just needs the length modified, so we
3706 * run it outside the loop.
3707 */
3708 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3709
3710 /* All the others need rx_buf/tx_buf also set */
3711 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3712 /* Update rx_buf, tx_buf and DMA */
3713 if (xfers[i].rx_buf)
3714 xfers[i].rx_buf += offset;
3715 if (xfers[i].tx_buf)
3716 xfers[i].tx_buf += offset;
3717
3718 /* Update length */
3719 xfers[i].len = min(maxsize, xfers[i].len - offset);
3720 }
3721
3722 /*
3723 * We set up xferp to the last entry we have inserted,
3724 * so that we skip those already split transfers.
3725 */
3726 *xferp = &xfers[count - 1];
3727
3728 /* Increment statistics counters */
3729 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,
3730 transfers_split_maxsize);
3731 SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,
3732 transfers_split_maxsize);
3733
3734 return 0;
3735}
3736
3737/**
3738 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3739 * when an individual transfer exceeds a
3740 * certain size
3741 * @ctlr: the @spi_controller for this transfer
3742 * @msg: the @spi_message to transform
3743 * @maxsize: the maximum when to apply this
3744 *
3745 * This function allocates resources that are automatically freed during the
3746 * spi message unoptimize phase so this function should only be called from
3747 * optimize_message callbacks.
3748 *
3749 * Return: status of transformation
3750 */
3751int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3752 struct spi_message *msg,
3753 size_t maxsize)
3754{
3755 struct spi_transfer *xfer;
3756 int ret;
3757
3758 /*
3759 * Iterate over the transfer_list,
3760 * but note that xfer is advanced to the last transfer inserted
3761 * to avoid checking sizes again unnecessarily (also xfer does
3762 * potentially belong to a different list by the time the
3763 * replacement has happened).
3764 */
3765 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3766 if (xfer->len > maxsize) {
3767 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3768 maxsize);
3769 if (ret)
3770 return ret;
3771 }
3772 }
3773
3774 return 0;
3775}
3776EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3777
3778
3779/**
3780 * spi_split_transfers_maxwords - split SPI transfers into multiple transfers
3781 * when an individual transfer exceeds a
3782 * certain number of SPI words
3783 * @ctlr: the @spi_controller for this transfer
3784 * @msg: the @spi_message to transform
3785 * @maxwords: the number of words to limit each transfer to
3786 *
3787 * This function allocates resources that are automatically freed during the
3788 * spi message unoptimize phase so this function should only be called from
3789 * optimize_message callbacks.
3790 *
3791 * Return: status of transformation
3792 */
3793int spi_split_transfers_maxwords(struct spi_controller *ctlr,
3794 struct spi_message *msg,
3795 size_t maxwords)
3796{
3797 struct spi_transfer *xfer;
3798
3799 /*
3800 * Iterate over the transfer_list,
3801 * but note that xfer is advanced to the last transfer inserted
3802 * to avoid checking sizes again unnecessarily (also xfer does
3803 * potentially belong to a different list by the time the
3804 * replacement has happened).
3805 */
3806 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3807 size_t maxsize;
3808 int ret;
3809
3810 maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word));
3811 if (xfer->len > maxsize) {
3812 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3813 maxsize);
3814 if (ret)
3815 return ret;
3816 }
3817 }
3818
3819 return 0;
3820}
3821EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords);
3822
3823/*-------------------------------------------------------------------------*/
3824
3825/*
3826 * Core methods for SPI controller protocol drivers. Some of the
3827 * other core methods are currently defined as inline functions.
3828 */
3829
3830static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3831 u8 bits_per_word)
3832{
3833 if (ctlr->bits_per_word_mask) {
3834 /* Only 32 bits fit in the mask */
3835 if (bits_per_word > 32)
3836 return -EINVAL;
3837 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3838 return -EINVAL;
3839 }
3840
3841 return 0;
3842}
3843
3844/**
3845 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3846 * @spi: the device that requires specific CS timing configuration
3847 *
3848 * Return: zero on success, else a negative error code.
3849 */
3850static int spi_set_cs_timing(struct spi_device *spi)
3851{
3852 struct device *parent = spi->controller->dev.parent;
3853 int status = 0;
3854
3855 if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) {
3856 if (spi->controller->auto_runtime_pm) {
3857 status = pm_runtime_get_sync(parent);
3858 if (status < 0) {
3859 pm_runtime_put_noidle(parent);
3860 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3861 status);
3862 return status;
3863 }
3864
3865 status = spi->controller->set_cs_timing(spi);
3866 pm_runtime_mark_last_busy(parent);
3867 pm_runtime_put_autosuspend(parent);
3868 } else {
3869 status = spi->controller->set_cs_timing(spi);
3870 }
3871 }
3872 return status;
3873}
3874
3875/**
3876 * spi_setup - setup SPI mode and clock rate
3877 * @spi: the device whose settings are being modified
3878 * Context: can sleep, and no requests are queued to the device
3879 *
3880 * SPI protocol drivers may need to update the transfer mode if the
3881 * device doesn't work with its default. They may likewise need
3882 * to update clock rates or word sizes from initial values. This function
3883 * changes those settings, and must be called from a context that can sleep.
3884 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3885 * effect the next time the device is selected and data is transferred to
3886 * or from it. When this function returns, the SPI device is deselected.
3887 *
3888 * Note that this call will fail if the protocol driver specifies an option
3889 * that the underlying controller or its driver does not support. For
3890 * example, not all hardware supports wire transfers using nine bit words,
3891 * LSB-first wire encoding, or active-high chipselects.
3892 *
3893 * Return: zero on success, else a negative error code.
3894 */
3895int spi_setup(struct spi_device *spi)
3896{
3897 unsigned bad_bits, ugly_bits;
3898 int status;
3899
3900 /*
3901 * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3902 * are set at the same time.
3903 */
3904 if ((hweight_long(spi->mode &
3905 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3906 (hweight_long(spi->mode &
3907 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3908 dev_err(&spi->dev,
3909 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3910 return -EINVAL;
3911 }
3912 /* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */
3913 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3914 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3915 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3916 return -EINVAL;
3917 /* Check against conflicting MOSI idle configuration */
3918 if ((spi->mode & SPI_MOSI_IDLE_LOW) && (spi->mode & SPI_MOSI_IDLE_HIGH)) {
3919 dev_err(&spi->dev,
3920 "setup: MOSI configured to idle low and high at the same time.\n");
3921 return -EINVAL;
3922 }
3923 /*
3924 * Help drivers fail *cleanly* when they need options
3925 * that aren't supported with their current controller.
3926 * SPI_CS_WORD has a fallback software implementation,
3927 * so it is ignored here.
3928 */
3929 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3930 SPI_NO_TX | SPI_NO_RX);
3931 ugly_bits = bad_bits &
3932 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3933 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3934 if (ugly_bits) {
3935 dev_warn(&spi->dev,
3936 "setup: ignoring unsupported mode bits %x\n",
3937 ugly_bits);
3938 spi->mode &= ~ugly_bits;
3939 bad_bits &= ~ugly_bits;
3940 }
3941 if (bad_bits) {
3942 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3943 bad_bits);
3944 return -EINVAL;
3945 }
3946
3947 if (!spi->bits_per_word) {
3948 spi->bits_per_word = 8;
3949 } else {
3950 /*
3951 * Some controllers may not support the default 8 bits-per-word
3952 * so only perform the check when this is explicitly provided.
3953 */
3954 status = __spi_validate_bits_per_word(spi->controller,
3955 spi->bits_per_word);
3956 if (status)
3957 return status;
3958 }
3959
3960 if (spi->controller->max_speed_hz &&
3961 (!spi->max_speed_hz ||
3962 spi->max_speed_hz > spi->controller->max_speed_hz))
3963 spi->max_speed_hz = spi->controller->max_speed_hz;
3964
3965 mutex_lock(&spi->controller->io_mutex);
3966
3967 if (spi->controller->setup) {
3968 status = spi->controller->setup(spi);
3969 if (status) {
3970 mutex_unlock(&spi->controller->io_mutex);
3971 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3972 status);
3973 return status;
3974 }
3975 }
3976
3977 status = spi_set_cs_timing(spi);
3978 if (status) {
3979 mutex_unlock(&spi->controller->io_mutex);
3980 return status;
3981 }
3982
3983 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3984 status = pm_runtime_resume_and_get(spi->controller->dev.parent);
3985 if (status < 0) {
3986 mutex_unlock(&spi->controller->io_mutex);
3987 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3988 status);
3989 return status;
3990 }
3991
3992 /*
3993 * We do not want to return positive value from pm_runtime_get,
3994 * there are many instances of devices calling spi_setup() and
3995 * checking for a non-zero return value instead of a negative
3996 * return value.
3997 */
3998 status = 0;
3999
4000 spi_set_cs(spi, false, true);
4001 pm_runtime_mark_last_busy(spi->controller->dev.parent);
4002 pm_runtime_put_autosuspend(spi->controller->dev.parent);
4003 } else {
4004 spi_set_cs(spi, false, true);
4005 }
4006
4007 mutex_unlock(&spi->controller->io_mutex);
4008
4009 if (spi->rt && !spi->controller->rt) {
4010 spi->controller->rt = true;
4011 spi_set_thread_rt(spi->controller);
4012 }
4013
4014 trace_spi_setup(spi, status);
4015
4016 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
4017 spi->mode & SPI_MODE_X_MASK,
4018 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
4019 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
4020 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
4021 (spi->mode & SPI_LOOP) ? "loopback, " : "",
4022 spi->bits_per_word, spi->max_speed_hz,
4023 status);
4024
4025 return status;
4026}
4027EXPORT_SYMBOL_GPL(spi_setup);
4028
4029static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
4030 struct spi_device *spi)
4031{
4032 int delay1, delay2;
4033
4034 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
4035 if (delay1 < 0)
4036 return delay1;
4037
4038 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
4039 if (delay2 < 0)
4040 return delay2;
4041
4042 if (delay1 < delay2)
4043 memcpy(&xfer->word_delay, &spi->word_delay,
4044 sizeof(xfer->word_delay));
4045
4046 return 0;
4047}
4048
4049static int __spi_validate(struct spi_device *spi, struct spi_message *message)
4050{
4051 struct spi_controller *ctlr = spi->controller;
4052 struct spi_transfer *xfer;
4053 int w_size;
4054
4055 if (list_empty(&message->transfers))
4056 return -EINVAL;
4057
4058 message->spi = spi;
4059
4060 /*
4061 * Half-duplex links include original MicroWire, and ones with
4062 * only one data pin like SPI_3WIRE (switches direction) or where
4063 * either MOSI or MISO is missing. They can also be caused by
4064 * software limitations.
4065 */
4066 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
4067 (spi->mode & SPI_3WIRE)) {
4068 unsigned flags = ctlr->flags;
4069
4070 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4071 if (xfer->rx_buf && xfer->tx_buf)
4072 return -EINVAL;
4073 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
4074 return -EINVAL;
4075 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
4076 return -EINVAL;
4077 }
4078 }
4079
4080 /*
4081 * Set transfer bits_per_word and max speed as spi device default if
4082 * it is not set for this transfer.
4083 * Set transfer tx_nbits and rx_nbits as single transfer default
4084 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
4085 * Ensure transfer word_delay is at least as long as that required by
4086 * device itself.
4087 */
4088 message->frame_length = 0;
4089 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4090 xfer->effective_speed_hz = 0;
4091 message->frame_length += xfer->len;
4092 if (!xfer->bits_per_word)
4093 xfer->bits_per_word = spi->bits_per_word;
4094
4095 if (!xfer->speed_hz)
4096 xfer->speed_hz = spi->max_speed_hz;
4097
4098 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
4099 xfer->speed_hz = ctlr->max_speed_hz;
4100
4101 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
4102 return -EINVAL;
4103
4104 /*
4105 * SPI transfer length should be multiple of SPI word size
4106 * where SPI word size should be power-of-two multiple.
4107 */
4108 if (xfer->bits_per_word <= 8)
4109 w_size = 1;
4110 else if (xfer->bits_per_word <= 16)
4111 w_size = 2;
4112 else
4113 w_size = 4;
4114
4115 /* No partial transfers accepted */
4116 if (xfer->len % w_size)
4117 return -EINVAL;
4118
4119 if (xfer->speed_hz && ctlr->min_speed_hz &&
4120 xfer->speed_hz < ctlr->min_speed_hz)
4121 return -EINVAL;
4122
4123 if (xfer->tx_buf && !xfer->tx_nbits)
4124 xfer->tx_nbits = SPI_NBITS_SINGLE;
4125 if (xfer->rx_buf && !xfer->rx_nbits)
4126 xfer->rx_nbits = SPI_NBITS_SINGLE;
4127 /*
4128 * Check transfer tx/rx_nbits:
4129 * 1. check the value matches one of single, dual and quad
4130 * 2. check tx/rx_nbits match the mode in spi_device
4131 */
4132 if (xfer->tx_buf) {
4133 if (spi->mode & SPI_NO_TX)
4134 return -EINVAL;
4135 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
4136 xfer->tx_nbits != SPI_NBITS_DUAL &&
4137 xfer->tx_nbits != SPI_NBITS_QUAD &&
4138 xfer->tx_nbits != SPI_NBITS_OCTAL)
4139 return -EINVAL;
4140 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
4141 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
4142 return -EINVAL;
4143 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
4144 !(spi->mode & SPI_TX_QUAD))
4145 return -EINVAL;
4146 }
4147 /* Check transfer rx_nbits */
4148 if (xfer->rx_buf) {
4149 if (spi->mode & SPI_NO_RX)
4150 return -EINVAL;
4151 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
4152 xfer->rx_nbits != SPI_NBITS_DUAL &&
4153 xfer->rx_nbits != SPI_NBITS_QUAD &&
4154 xfer->rx_nbits != SPI_NBITS_OCTAL)
4155 return -EINVAL;
4156 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
4157 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
4158 return -EINVAL;
4159 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
4160 !(spi->mode & SPI_RX_QUAD))
4161 return -EINVAL;
4162 }
4163
4164 if (_spi_xfer_word_delay_update(xfer, spi))
4165 return -EINVAL;
4166 }
4167
4168 message->status = -EINPROGRESS;
4169
4170 return 0;
4171}
4172
4173/*
4174 * spi_split_transfers - generic handling of transfer splitting
4175 * @msg: the message to split
4176 *
4177 * Under certain conditions, a SPI controller may not support arbitrary
4178 * transfer sizes or other features required by a peripheral. This function
4179 * will split the transfers in the message into smaller transfers that are
4180 * supported by the controller.
4181 *
4182 * Controllers with special requirements not covered here can also split
4183 * transfers in the optimize_message() callback.
4184 *
4185 * Context: can sleep
4186 * Return: zero on success, else a negative error code
4187 */
4188static int spi_split_transfers(struct spi_message *msg)
4189{
4190 struct spi_controller *ctlr = msg->spi->controller;
4191 struct spi_transfer *xfer;
4192 int ret;
4193
4194 /*
4195 * If an SPI controller does not support toggling the CS line on each
4196 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
4197 * for the CS line, we can emulate the CS-per-word hardware function by
4198 * splitting transfers into one-word transfers and ensuring that
4199 * cs_change is set for each transfer.
4200 */
4201 if ((msg->spi->mode & SPI_CS_WORD) &&
4202 (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) {
4203 ret = spi_split_transfers_maxwords(ctlr, msg, 1);
4204 if (ret)
4205 return ret;
4206
4207 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
4208 /* Don't change cs_change on the last entry in the list */
4209 if (list_is_last(&xfer->transfer_list, &msg->transfers))
4210 break;
4211
4212 xfer->cs_change = 1;
4213 }
4214 } else {
4215 ret = spi_split_transfers_maxsize(ctlr, msg,
4216 spi_max_transfer_size(msg->spi));
4217 if (ret)
4218 return ret;
4219 }
4220
4221 return 0;
4222}
4223
4224/*
4225 * __spi_optimize_message - shared implementation for spi_optimize_message()
4226 * and spi_maybe_optimize_message()
4227 * @spi: the device that will be used for the message
4228 * @msg: the message to optimize
4229 *
4230 * Peripheral drivers will call spi_optimize_message() and the spi core will
4231 * call spi_maybe_optimize_message() instead of calling this directly.
4232 *
4233 * It is not valid to call this on a message that has already been optimized.
4234 *
4235 * Return: zero on success, else a negative error code
4236 */
4237static int __spi_optimize_message(struct spi_device *spi,
4238 struct spi_message *msg)
4239{
4240 struct spi_controller *ctlr = spi->controller;
4241 int ret;
4242
4243 ret = __spi_validate(spi, msg);
4244 if (ret)
4245 return ret;
4246
4247 ret = spi_split_transfers(msg);
4248 if (ret)
4249 return ret;
4250
4251 if (ctlr->optimize_message) {
4252 ret = ctlr->optimize_message(msg);
4253 if (ret) {
4254 spi_res_release(ctlr, msg);
4255 return ret;
4256 }
4257 }
4258
4259 msg->optimized = true;
4260
4261 return 0;
4262}
4263
4264/*
4265 * spi_maybe_optimize_message - optimize message if it isn't already pre-optimized
4266 * @spi: the device that will be used for the message
4267 * @msg: the message to optimize
4268 * Return: zero on success, else a negative error code
4269 */
4270static int spi_maybe_optimize_message(struct spi_device *spi,
4271 struct spi_message *msg)
4272{
4273 if (spi->controller->defer_optimize_message) {
4274 msg->spi = spi;
4275 return 0;
4276 }
4277
4278 if (msg->pre_optimized)
4279 return 0;
4280
4281 return __spi_optimize_message(spi, msg);
4282}
4283
4284/**
4285 * spi_optimize_message - do any one-time validation and setup for a SPI message
4286 * @spi: the device that will be used for the message
4287 * @msg: the message to optimize
4288 *
4289 * Peripheral drivers that reuse the same message repeatedly may call this to
4290 * perform as much message prep as possible once, rather than repeating it each
4291 * time a message transfer is performed to improve throughput and reduce CPU
4292 * usage.
4293 *
4294 * Once a message has been optimized, it cannot be modified with the exception
4295 * of updating the contents of any xfer->tx_buf (the pointer can't be changed,
4296 * only the data in the memory it points to).
4297 *
4298 * Calls to this function must be balanced with calls to spi_unoptimize_message()
4299 * to avoid leaking resources.
4300 *
4301 * Context: can sleep
4302 * Return: zero on success, else a negative error code
4303 */
4304int spi_optimize_message(struct spi_device *spi, struct spi_message *msg)
4305{
4306 int ret;
4307
4308 /*
4309 * Pre-optimization is not supported and optimization is deferred e.g.
4310 * when using spi-mux.
4311 */
4312 if (spi->controller->defer_optimize_message)
4313 return 0;
4314
4315 ret = __spi_optimize_message(spi, msg);
4316 if (ret)
4317 return ret;
4318
4319 /*
4320 * This flag indicates that the peripheral driver called spi_optimize_message()
4321 * and therefore we shouldn't unoptimize message automatically when finalizing
4322 * the message but rather wait until spi_unoptimize_message() is called
4323 * by the peripheral driver.
4324 */
4325 msg->pre_optimized = true;
4326
4327 return 0;
4328}
4329EXPORT_SYMBOL_GPL(spi_optimize_message);
4330
4331/**
4332 * spi_unoptimize_message - releases any resources allocated by spi_optimize_message()
4333 * @msg: the message to unoptimize
4334 *
4335 * Calls to this function must be balanced with calls to spi_optimize_message().
4336 *
4337 * Context: can sleep
4338 */
4339void spi_unoptimize_message(struct spi_message *msg)
4340{
4341 if (msg->spi->controller->defer_optimize_message)
4342 return;
4343
4344 __spi_unoptimize_message(msg);
4345 msg->pre_optimized = false;
4346}
4347EXPORT_SYMBOL_GPL(spi_unoptimize_message);
4348
4349static int __spi_async(struct spi_device *spi, struct spi_message *message)
4350{
4351 struct spi_controller *ctlr = spi->controller;
4352 struct spi_transfer *xfer;
4353
4354 /*
4355 * Some controllers do not support doing regular SPI transfers. Return
4356 * ENOTSUPP when this is the case.
4357 */
4358 if (!ctlr->transfer)
4359 return -ENOTSUPP;
4360
4361 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);
4362 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);
4363
4364 trace_spi_message_submit(message);
4365
4366 if (!ctlr->ptp_sts_supported) {
4367 list_for_each_entry(xfer, &message->transfers, transfer_list) {
4368 xfer->ptp_sts_word_pre = 0;
4369 ptp_read_system_prets(xfer->ptp_sts);
4370 }
4371 }
4372
4373 return ctlr->transfer(spi, message);
4374}
4375
4376static void devm_spi_unoptimize_message(void *msg)
4377{
4378 spi_unoptimize_message(msg);
4379}
4380
4381/**
4382 * devm_spi_optimize_message - managed version of spi_optimize_message()
4383 * @dev: the device that manages @msg (usually @spi->dev)
4384 * @spi: the device that will be used for the message
4385 * @msg: the message to optimize
4386 * Return: zero on success, else a negative error code
4387 *
4388 * spi_unoptimize_message() will automatically be called when the device is
4389 * removed.
4390 */
4391int devm_spi_optimize_message(struct device *dev, struct spi_device *spi,
4392 struct spi_message *msg)
4393{
4394 int ret;
4395
4396 ret = spi_optimize_message(spi, msg);
4397 if (ret)
4398 return ret;
4399
4400 return devm_add_action_or_reset(dev, devm_spi_unoptimize_message, msg);
4401}
4402EXPORT_SYMBOL_GPL(devm_spi_optimize_message);
4403
4404/**
4405 * spi_async - asynchronous SPI transfer
4406 * @spi: device with which data will be exchanged
4407 * @message: describes the data transfers, including completion callback
4408 * Context: any (IRQs may be blocked, etc)
4409 *
4410 * This call may be used in_irq and other contexts which can't sleep,
4411 * as well as from task contexts which can sleep.
4412 *
4413 * The completion callback is invoked in a context which can't sleep.
4414 * Before that invocation, the value of message->status is undefined.
4415 * When the callback is issued, message->status holds either zero (to
4416 * indicate complete success) or a negative error code. After that
4417 * callback returns, the driver which issued the transfer request may
4418 * deallocate the associated memory; it's no longer in use by any SPI
4419 * core or controller driver code.
4420 *
4421 * Note that although all messages to a spi_device are handled in
4422 * FIFO order, messages may go to different devices in other orders.
4423 * Some device might be higher priority, or have various "hard" access
4424 * time requirements, for example.
4425 *
4426 * On detection of any fault during the transfer, processing of
4427 * the entire message is aborted, and the device is deselected.
4428 * Until returning from the associated message completion callback,
4429 * no other spi_message queued to that device will be processed.
4430 * (This rule applies equally to all the synchronous transfer calls,
4431 * which are wrappers around this core asynchronous primitive.)
4432 *
4433 * Return: zero on success, else a negative error code.
4434 */
4435int spi_async(struct spi_device *spi, struct spi_message *message)
4436{
4437 struct spi_controller *ctlr = spi->controller;
4438 int ret;
4439 unsigned long flags;
4440
4441 ret = spi_maybe_optimize_message(spi, message);
4442 if (ret)
4443 return ret;
4444
4445 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4446
4447 if (ctlr->bus_lock_flag)
4448 ret = -EBUSY;
4449 else
4450 ret = __spi_async(spi, message);
4451
4452 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4453
4454 return ret;
4455}
4456EXPORT_SYMBOL_GPL(spi_async);
4457
4458static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)
4459{
4460 bool was_busy;
4461 int ret;
4462
4463 mutex_lock(&ctlr->io_mutex);
4464
4465 was_busy = ctlr->busy;
4466
4467 ctlr->cur_msg = msg;
4468 ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
4469 if (ret)
4470 dev_err(&ctlr->dev, "noqueue transfer failed\n");
4471 ctlr->cur_msg = NULL;
4472 ctlr->fallback = false;
4473
4474 if (!was_busy) {
4475 kfree(ctlr->dummy_rx);
4476 ctlr->dummy_rx = NULL;
4477 kfree(ctlr->dummy_tx);
4478 ctlr->dummy_tx = NULL;
4479 if (ctlr->unprepare_transfer_hardware &&
4480 ctlr->unprepare_transfer_hardware(ctlr))
4481 dev_err(&ctlr->dev,
4482 "failed to unprepare transfer hardware\n");
4483 spi_idle_runtime_pm(ctlr);
4484 }
4485
4486 mutex_unlock(&ctlr->io_mutex);
4487}
4488
4489/*-------------------------------------------------------------------------*/
4490
4491/*
4492 * Utility methods for SPI protocol drivers, layered on
4493 * top of the core. Some other utility methods are defined as
4494 * inline functions.
4495 */
4496
4497static void spi_complete(void *arg)
4498{
4499 complete(arg);
4500}
4501
4502static int __spi_sync(struct spi_device *spi, struct spi_message *message)
4503{
4504 DECLARE_COMPLETION_ONSTACK(done);
4505 unsigned long flags;
4506 int status;
4507 struct spi_controller *ctlr = spi->controller;
4508
4509 if (__spi_check_suspended(ctlr)) {
4510 dev_warn_once(&spi->dev, "Attempted to sync while suspend\n");
4511 return -ESHUTDOWN;
4512 }
4513
4514 status = spi_maybe_optimize_message(spi, message);
4515 if (status)
4516 return status;
4517
4518 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);
4519 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);
4520
4521 /*
4522 * Checking queue_empty here only guarantees async/sync message
4523 * ordering when coming from the same context. It does not need to
4524 * guard against reentrancy from a different context. The io_mutex
4525 * will catch those cases.
4526 */
4527 if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) {
4528 message->actual_length = 0;
4529 message->status = -EINPROGRESS;
4530
4531 trace_spi_message_submit(message);
4532
4533 SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);
4534 SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);
4535
4536 __spi_transfer_message_noqueue(ctlr, message);
4537
4538 return message->status;
4539 }
4540
4541 /*
4542 * There are messages in the async queue that could have originated
4543 * from the same context, so we need to preserve ordering.
4544 * Therefor we send the message to the async queue and wait until they
4545 * are completed.
4546 */
4547 message->complete = spi_complete;
4548 message->context = &done;
4549
4550 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4551 status = __spi_async(spi, message);
4552 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4553
4554 if (status == 0) {
4555 wait_for_completion(&done);
4556 status = message->status;
4557 }
4558 message->complete = NULL;
4559 message->context = NULL;
4560
4561 return status;
4562}
4563
4564/**
4565 * spi_sync - blocking/synchronous SPI data transfers
4566 * @spi: device with which data will be exchanged
4567 * @message: describes the data transfers
4568 * Context: can sleep
4569 *
4570 * This call may only be used from a context that may sleep. The sleep
4571 * is non-interruptible, and has no timeout. Low-overhead controller
4572 * drivers may DMA directly into and out of the message buffers.
4573 *
4574 * Note that the SPI device's chip select is active during the message,
4575 * and then is normally disabled between messages. Drivers for some
4576 * frequently-used devices may want to minimize costs of selecting a chip,
4577 * by leaving it selected in anticipation that the next message will go
4578 * to the same chip. (That may increase power usage.)
4579 *
4580 * Also, the caller is guaranteeing that the memory associated with the
4581 * message will not be freed before this call returns.
4582 *
4583 * Return: zero on success, else a negative error code.
4584 */
4585int spi_sync(struct spi_device *spi, struct spi_message *message)
4586{
4587 int ret;
4588
4589 mutex_lock(&spi->controller->bus_lock_mutex);
4590 ret = __spi_sync(spi, message);
4591 mutex_unlock(&spi->controller->bus_lock_mutex);
4592
4593 return ret;
4594}
4595EXPORT_SYMBOL_GPL(spi_sync);
4596
4597/**
4598 * spi_sync_locked - version of spi_sync with exclusive bus usage
4599 * @spi: device with which data will be exchanged
4600 * @message: describes the data transfers
4601 * Context: can sleep
4602 *
4603 * This call may only be used from a context that may sleep. The sleep
4604 * is non-interruptible, and has no timeout. Low-overhead controller
4605 * drivers may DMA directly into and out of the message buffers.
4606 *
4607 * This call should be used by drivers that require exclusive access to the
4608 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
4609 * be released by a spi_bus_unlock call when the exclusive access is over.
4610 *
4611 * Return: zero on success, else a negative error code.
4612 */
4613int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
4614{
4615 return __spi_sync(spi, message);
4616}
4617EXPORT_SYMBOL_GPL(spi_sync_locked);
4618
4619/**
4620 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
4621 * @ctlr: SPI bus master that should be locked for exclusive bus access
4622 * Context: can sleep
4623 *
4624 * This call may only be used from a context that may sleep. The sleep
4625 * is non-interruptible, and has no timeout.
4626 *
4627 * This call should be used by drivers that require exclusive access to the
4628 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
4629 * exclusive access is over. Data transfer must be done by spi_sync_locked
4630 * and spi_async_locked calls when the SPI bus lock is held.
4631 *
4632 * Return: always zero.
4633 */
4634int spi_bus_lock(struct spi_controller *ctlr)
4635{
4636 unsigned long flags;
4637
4638 mutex_lock(&ctlr->bus_lock_mutex);
4639
4640 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
4641 ctlr->bus_lock_flag = 1;
4642 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
4643
4644 /* Mutex remains locked until spi_bus_unlock() is called */
4645
4646 return 0;
4647}
4648EXPORT_SYMBOL_GPL(spi_bus_lock);
4649
4650/**
4651 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4652 * @ctlr: SPI bus master that was locked for exclusive bus access
4653 * Context: can sleep
4654 *
4655 * This call may only be used from a context that may sleep. The sleep
4656 * is non-interruptible, and has no timeout.
4657 *
4658 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4659 * call.
4660 *
4661 * Return: always zero.
4662 */
4663int spi_bus_unlock(struct spi_controller *ctlr)
4664{
4665 ctlr->bus_lock_flag = 0;
4666
4667 mutex_unlock(&ctlr->bus_lock_mutex);
4668
4669 return 0;
4670}
4671EXPORT_SYMBOL_GPL(spi_bus_unlock);
4672
4673/* Portable code must never pass more than 32 bytes */
4674#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4675
4676static u8 *buf;
4677
4678/**
4679 * spi_write_then_read - SPI synchronous write followed by read
4680 * @spi: device with which data will be exchanged
4681 * @txbuf: data to be written (need not be DMA-safe)
4682 * @n_tx: size of txbuf, in bytes
4683 * @rxbuf: buffer into which data will be read (need not be DMA-safe)
4684 * @n_rx: size of rxbuf, in bytes
4685 * Context: can sleep
4686 *
4687 * This performs a half duplex MicroWire style transaction with the
4688 * device, sending txbuf and then reading rxbuf. The return value
4689 * is zero for success, else a negative errno status code.
4690 * This call may only be used from a context that may sleep.
4691 *
4692 * Parameters to this routine are always copied using a small buffer.
4693 * Performance-sensitive or bulk transfer code should instead use
4694 * spi_{async,sync}() calls with DMA-safe buffers.
4695 *
4696 * Return: zero on success, else a negative error code.
4697 */
4698int spi_write_then_read(struct spi_device *spi,
4699 const void *txbuf, unsigned n_tx,
4700 void *rxbuf, unsigned n_rx)
4701{
4702 static DEFINE_MUTEX(lock);
4703
4704 int status;
4705 struct spi_message message;
4706 struct spi_transfer x[2];
4707 u8 *local_buf;
4708
4709 /*
4710 * Use preallocated DMA-safe buffer if we can. We can't avoid
4711 * copying here, (as a pure convenience thing), but we can
4712 * keep heap costs out of the hot path unless someone else is
4713 * using the pre-allocated buffer or the transfer is too large.
4714 */
4715 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4716 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4717 GFP_KERNEL | GFP_DMA);
4718 if (!local_buf)
4719 return -ENOMEM;
4720 } else {
4721 local_buf = buf;
4722 }
4723
4724 spi_message_init(&message);
4725 memset(x, 0, sizeof(x));
4726 if (n_tx) {
4727 x[0].len = n_tx;
4728 spi_message_add_tail(&x[0], &message);
4729 }
4730 if (n_rx) {
4731 x[1].len = n_rx;
4732 spi_message_add_tail(&x[1], &message);
4733 }
4734
4735 memcpy(local_buf, txbuf, n_tx);
4736 x[0].tx_buf = local_buf;
4737 x[1].rx_buf = local_buf + n_tx;
4738
4739 /* Do the I/O */
4740 status = spi_sync(spi, &message);
4741 if (status == 0)
4742 memcpy(rxbuf, x[1].rx_buf, n_rx);
4743
4744 if (x[0].tx_buf == buf)
4745 mutex_unlock(&lock);
4746 else
4747 kfree(local_buf);
4748
4749 return status;
4750}
4751EXPORT_SYMBOL_GPL(spi_write_then_read);
4752
4753/*-------------------------------------------------------------------------*/
4754
4755#if IS_ENABLED(CONFIG_OF_DYNAMIC)
4756/* Must call put_device() when done with returned spi_device device */
4757static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4758{
4759 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4760
4761 return dev ? to_spi_device(dev) : NULL;
4762}
4763
4764/* The spi controllers are not using spi_bus, so we find it with another way */
4765static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4766{
4767 struct device *dev;
4768
4769 dev = class_find_device_by_of_node(&spi_master_class, node);
4770 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4771 dev = class_find_device_by_of_node(&spi_slave_class, node);
4772 if (!dev)
4773 return NULL;
4774
4775 /* Reference got in class_find_device */
4776 return container_of(dev, struct spi_controller, dev);
4777}
4778
4779static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4780 void *arg)
4781{
4782 struct of_reconfig_data *rd = arg;
4783 struct spi_controller *ctlr;
4784 struct spi_device *spi;
4785
4786 switch (of_reconfig_get_state_change(action, arg)) {
4787 case OF_RECONFIG_CHANGE_ADD:
4788 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4789 if (ctlr == NULL)
4790 return NOTIFY_OK; /* Not for us */
4791
4792 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4793 put_device(&ctlr->dev);
4794 return NOTIFY_OK;
4795 }
4796
4797 /*
4798 * Clear the flag before adding the device so that fw_devlink
4799 * doesn't skip adding consumers to this device.
4800 */
4801 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
4802 spi = of_register_spi_device(ctlr, rd->dn);
4803 put_device(&ctlr->dev);
4804
4805 if (IS_ERR(spi)) {
4806 pr_err("%s: failed to create for '%pOF'\n",
4807 __func__, rd->dn);
4808 of_node_clear_flag(rd->dn, OF_POPULATED);
4809 return notifier_from_errno(PTR_ERR(spi));
4810 }
4811 break;
4812
4813 case OF_RECONFIG_CHANGE_REMOVE:
4814 /* Already depopulated? */
4815 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4816 return NOTIFY_OK;
4817
4818 /* Find our device by node */
4819 spi = of_find_spi_device_by_node(rd->dn);
4820 if (spi == NULL)
4821 return NOTIFY_OK; /* No? not meant for us */
4822
4823 /* Unregister takes one ref away */
4824 spi_unregister_device(spi);
4825
4826 /* And put the reference of the find */
4827 put_device(&spi->dev);
4828 break;
4829 }
4830
4831 return NOTIFY_OK;
4832}
4833
4834static struct notifier_block spi_of_notifier = {
4835 .notifier_call = of_spi_notify,
4836};
4837#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4838extern struct notifier_block spi_of_notifier;
4839#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4840
4841#if IS_ENABLED(CONFIG_ACPI)
4842static int spi_acpi_controller_match(struct device *dev, const void *data)
4843{
4844 return ACPI_COMPANION(dev->parent) == data;
4845}
4846
4847struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4848{
4849 struct device *dev;
4850
4851 dev = class_find_device(&spi_master_class, NULL, adev,
4852 spi_acpi_controller_match);
4853 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4854 dev = class_find_device(&spi_slave_class, NULL, adev,
4855 spi_acpi_controller_match);
4856 if (!dev)
4857 return NULL;
4858
4859 return container_of(dev, struct spi_controller, dev);
4860}
4861EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev);
4862
4863static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4864{
4865 struct device *dev;
4866
4867 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4868 return to_spi_device(dev);
4869}
4870
4871static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4872 void *arg)
4873{
4874 struct acpi_device *adev = arg;
4875 struct spi_controller *ctlr;
4876 struct spi_device *spi;
4877
4878 switch (value) {
4879 case ACPI_RECONFIG_DEVICE_ADD:
4880 ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev));
4881 if (!ctlr)
4882 break;
4883
4884 acpi_register_spi_device(ctlr, adev);
4885 put_device(&ctlr->dev);
4886 break;
4887 case ACPI_RECONFIG_DEVICE_REMOVE:
4888 if (!acpi_device_enumerated(adev))
4889 break;
4890
4891 spi = acpi_spi_find_device_by_adev(adev);
4892 if (!spi)
4893 break;
4894
4895 spi_unregister_device(spi);
4896 put_device(&spi->dev);
4897 break;
4898 }
4899
4900 return NOTIFY_OK;
4901}
4902
4903static struct notifier_block spi_acpi_notifier = {
4904 .notifier_call = acpi_spi_notify,
4905};
4906#else
4907extern struct notifier_block spi_acpi_notifier;
4908#endif
4909
4910static int __init spi_init(void)
4911{
4912 int status;
4913
4914 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4915 if (!buf) {
4916 status = -ENOMEM;
4917 goto err0;
4918 }
4919
4920 status = bus_register(&spi_bus_type);
4921 if (status < 0)
4922 goto err1;
4923
4924 status = class_register(&spi_master_class);
4925 if (status < 0)
4926 goto err2;
4927
4928 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4929 status = class_register(&spi_slave_class);
4930 if (status < 0)
4931 goto err3;
4932 }
4933
4934 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4935 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4936 if (IS_ENABLED(CONFIG_ACPI))
4937 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4938
4939 return 0;
4940
4941err3:
4942 class_unregister(&spi_master_class);
4943err2:
4944 bus_unregister(&spi_bus_type);
4945err1:
4946 kfree(buf);
4947 buf = NULL;
4948err0:
4949 return status;
4950}
4951
4952/*
4953 * A board_info is normally registered in arch_initcall(),
4954 * but even essential drivers wait till later.
4955 *
4956 * REVISIT only boardinfo really needs static linking. The rest (device and
4957 * driver registration) _could_ be dynamically linked (modular) ... Costs
4958 * include needing to have boardinfo data structures be much more public.
4959 */
4960postcore_initcall(spi_init);
1// SPDX-License-Identifier: GPL-2.0-or-later
2// SPI init/core code
3//
4// Copyright (C) 2005 David Brownell
5// Copyright (C) 2008 Secret Lab Technologies Ltd.
6
7#include <linux/kernel.h>
8#include <linux/device.h>
9#include <linux/init.h>
10#include <linux/cache.h>
11#include <linux/dma-mapping.h>
12#include <linux/dmaengine.h>
13#include <linux/mutex.h>
14#include <linux/of_device.h>
15#include <linux/of_irq.h>
16#include <linux/clk/clk-conf.h>
17#include <linux/slab.h>
18#include <linux/mod_devicetable.h>
19#include <linux/spi/spi.h>
20#include <linux/spi/spi-mem.h>
21#include <linux/of_gpio.h>
22#include <linux/gpio/consumer.h>
23#include <linux/pm_runtime.h>
24#include <linux/pm_domain.h>
25#include <linux/property.h>
26#include <linux/export.h>
27#include <linux/sched/rt.h>
28#include <uapi/linux/sched/types.h>
29#include <linux/delay.h>
30#include <linux/kthread.h>
31#include <linux/ioport.h>
32#include <linux/acpi.h>
33#include <linux/highmem.h>
34#include <linux/idr.h>
35#include <linux/platform_data/x86/apple.h>
36
37#define CREATE_TRACE_POINTS
38#include <trace/events/spi.h>
39EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
40EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
41
42#include "internals.h"
43
44static DEFINE_IDR(spi_master_idr);
45
46static void spidev_release(struct device *dev)
47{
48 struct spi_device *spi = to_spi_device(dev);
49
50 spi_controller_put(spi->controller);
51 kfree(spi->driver_override);
52 kfree(spi);
53}
54
55static ssize_t
56modalias_show(struct device *dev, struct device_attribute *a, char *buf)
57{
58 const struct spi_device *spi = to_spi_device(dev);
59 int len;
60
61 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
62 if (len != -ENODEV)
63 return len;
64
65 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
66}
67static DEVICE_ATTR_RO(modalias);
68
69static ssize_t driver_override_store(struct device *dev,
70 struct device_attribute *a,
71 const char *buf, size_t count)
72{
73 struct spi_device *spi = to_spi_device(dev);
74 const char *end = memchr(buf, '\n', count);
75 const size_t len = end ? end - buf : count;
76 const char *driver_override, *old;
77
78 /* We need to keep extra room for a newline when displaying value */
79 if (len >= (PAGE_SIZE - 1))
80 return -EINVAL;
81
82 driver_override = kstrndup(buf, len, GFP_KERNEL);
83 if (!driver_override)
84 return -ENOMEM;
85
86 device_lock(dev);
87 old = spi->driver_override;
88 if (len) {
89 spi->driver_override = driver_override;
90 } else {
91 /* Empty string, disable driver override */
92 spi->driver_override = NULL;
93 kfree(driver_override);
94 }
95 device_unlock(dev);
96 kfree(old);
97
98 return count;
99}
100
101static ssize_t driver_override_show(struct device *dev,
102 struct device_attribute *a, char *buf)
103{
104 const struct spi_device *spi = to_spi_device(dev);
105 ssize_t len;
106
107 device_lock(dev);
108 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
109 device_unlock(dev);
110 return len;
111}
112static DEVICE_ATTR_RW(driver_override);
113
114#define SPI_STATISTICS_ATTRS(field, file) \
115static ssize_t spi_controller_##field##_show(struct device *dev, \
116 struct device_attribute *attr, \
117 char *buf) \
118{ \
119 struct spi_controller *ctlr = container_of(dev, \
120 struct spi_controller, dev); \
121 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
122} \
123static struct device_attribute dev_attr_spi_controller_##field = { \
124 .attr = { .name = file, .mode = 0444 }, \
125 .show = spi_controller_##field##_show, \
126}; \
127static ssize_t spi_device_##field##_show(struct device *dev, \
128 struct device_attribute *attr, \
129 char *buf) \
130{ \
131 struct spi_device *spi = to_spi_device(dev); \
132 return spi_statistics_##field##_show(&spi->statistics, buf); \
133} \
134static struct device_attribute dev_attr_spi_device_##field = { \
135 .attr = { .name = file, .mode = 0444 }, \
136 .show = spi_device_##field##_show, \
137}
138
139#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
140static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
141 char *buf) \
142{ \
143 unsigned long flags; \
144 ssize_t len; \
145 spin_lock_irqsave(&stat->lock, flags); \
146 len = sprintf(buf, format_string, stat->field); \
147 spin_unlock_irqrestore(&stat->lock, flags); \
148 return len; \
149} \
150SPI_STATISTICS_ATTRS(name, file)
151
152#define SPI_STATISTICS_SHOW(field, format_string) \
153 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
154 field, format_string)
155
156SPI_STATISTICS_SHOW(messages, "%lu");
157SPI_STATISTICS_SHOW(transfers, "%lu");
158SPI_STATISTICS_SHOW(errors, "%lu");
159SPI_STATISTICS_SHOW(timedout, "%lu");
160
161SPI_STATISTICS_SHOW(spi_sync, "%lu");
162SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
163SPI_STATISTICS_SHOW(spi_async, "%lu");
164
165SPI_STATISTICS_SHOW(bytes, "%llu");
166SPI_STATISTICS_SHOW(bytes_rx, "%llu");
167SPI_STATISTICS_SHOW(bytes_tx, "%llu");
168
169#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
170 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
171 "transfer_bytes_histo_" number, \
172 transfer_bytes_histo[index], "%lu")
173SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
174SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
175SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
176SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
177SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
178SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
179SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
180SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
181SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
182SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
183SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
184SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
185SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
186SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
187SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
188SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
189SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
190
191SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
192
193static struct attribute *spi_dev_attrs[] = {
194 &dev_attr_modalias.attr,
195 &dev_attr_driver_override.attr,
196 NULL,
197};
198
199static const struct attribute_group spi_dev_group = {
200 .attrs = spi_dev_attrs,
201};
202
203static struct attribute *spi_device_statistics_attrs[] = {
204 &dev_attr_spi_device_messages.attr,
205 &dev_attr_spi_device_transfers.attr,
206 &dev_attr_spi_device_errors.attr,
207 &dev_attr_spi_device_timedout.attr,
208 &dev_attr_spi_device_spi_sync.attr,
209 &dev_attr_spi_device_spi_sync_immediate.attr,
210 &dev_attr_spi_device_spi_async.attr,
211 &dev_attr_spi_device_bytes.attr,
212 &dev_attr_spi_device_bytes_rx.attr,
213 &dev_attr_spi_device_bytes_tx.attr,
214 &dev_attr_spi_device_transfer_bytes_histo0.attr,
215 &dev_attr_spi_device_transfer_bytes_histo1.attr,
216 &dev_attr_spi_device_transfer_bytes_histo2.attr,
217 &dev_attr_spi_device_transfer_bytes_histo3.attr,
218 &dev_attr_spi_device_transfer_bytes_histo4.attr,
219 &dev_attr_spi_device_transfer_bytes_histo5.attr,
220 &dev_attr_spi_device_transfer_bytes_histo6.attr,
221 &dev_attr_spi_device_transfer_bytes_histo7.attr,
222 &dev_attr_spi_device_transfer_bytes_histo8.attr,
223 &dev_attr_spi_device_transfer_bytes_histo9.attr,
224 &dev_attr_spi_device_transfer_bytes_histo10.attr,
225 &dev_attr_spi_device_transfer_bytes_histo11.attr,
226 &dev_attr_spi_device_transfer_bytes_histo12.attr,
227 &dev_attr_spi_device_transfer_bytes_histo13.attr,
228 &dev_attr_spi_device_transfer_bytes_histo14.attr,
229 &dev_attr_spi_device_transfer_bytes_histo15.attr,
230 &dev_attr_spi_device_transfer_bytes_histo16.attr,
231 &dev_attr_spi_device_transfers_split_maxsize.attr,
232 NULL,
233};
234
235static const struct attribute_group spi_device_statistics_group = {
236 .name = "statistics",
237 .attrs = spi_device_statistics_attrs,
238};
239
240static const struct attribute_group *spi_dev_groups[] = {
241 &spi_dev_group,
242 &spi_device_statistics_group,
243 NULL,
244};
245
246static struct attribute *spi_controller_statistics_attrs[] = {
247 &dev_attr_spi_controller_messages.attr,
248 &dev_attr_spi_controller_transfers.attr,
249 &dev_attr_spi_controller_errors.attr,
250 &dev_attr_spi_controller_timedout.attr,
251 &dev_attr_spi_controller_spi_sync.attr,
252 &dev_attr_spi_controller_spi_sync_immediate.attr,
253 &dev_attr_spi_controller_spi_async.attr,
254 &dev_attr_spi_controller_bytes.attr,
255 &dev_attr_spi_controller_bytes_rx.attr,
256 &dev_attr_spi_controller_bytes_tx.attr,
257 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
258 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
259 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
260 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
274 &dev_attr_spi_controller_transfers_split_maxsize.attr,
275 NULL,
276};
277
278static const struct attribute_group spi_controller_statistics_group = {
279 .name = "statistics",
280 .attrs = spi_controller_statistics_attrs,
281};
282
283static const struct attribute_group *spi_master_groups[] = {
284 &spi_controller_statistics_group,
285 NULL,
286};
287
288void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
289 struct spi_transfer *xfer,
290 struct spi_controller *ctlr)
291{
292 unsigned long flags;
293 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
294
295 if (l2len < 0)
296 l2len = 0;
297
298 spin_lock_irqsave(&stats->lock, flags);
299
300 stats->transfers++;
301 stats->transfer_bytes_histo[l2len]++;
302
303 stats->bytes += xfer->len;
304 if ((xfer->tx_buf) &&
305 (xfer->tx_buf != ctlr->dummy_tx))
306 stats->bytes_tx += xfer->len;
307 if ((xfer->rx_buf) &&
308 (xfer->rx_buf != ctlr->dummy_rx))
309 stats->bytes_rx += xfer->len;
310
311 spin_unlock_irqrestore(&stats->lock, flags);
312}
313EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
314
315/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
316 * and the sysfs version makes coldplug work too.
317 */
318
319static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
320 const struct spi_device *sdev)
321{
322 while (id->name[0]) {
323 if (!strcmp(sdev->modalias, id->name))
324 return id;
325 id++;
326 }
327 return NULL;
328}
329
330const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
331{
332 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
333
334 return spi_match_id(sdrv->id_table, sdev);
335}
336EXPORT_SYMBOL_GPL(spi_get_device_id);
337
338static int spi_match_device(struct device *dev, struct device_driver *drv)
339{
340 const struct spi_device *spi = to_spi_device(dev);
341 const struct spi_driver *sdrv = to_spi_driver(drv);
342
343 /* Check override first, and if set, only use the named driver */
344 if (spi->driver_override)
345 return strcmp(spi->driver_override, drv->name) == 0;
346
347 /* Attempt an OF style match */
348 if (of_driver_match_device(dev, drv))
349 return 1;
350
351 /* Then try ACPI */
352 if (acpi_driver_match_device(dev, drv))
353 return 1;
354
355 if (sdrv->id_table)
356 return !!spi_match_id(sdrv->id_table, spi);
357
358 return strcmp(spi->modalias, drv->name) == 0;
359}
360
361static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
362{
363 const struct spi_device *spi = to_spi_device(dev);
364 int rc;
365
366 rc = acpi_device_uevent_modalias(dev, env);
367 if (rc != -ENODEV)
368 return rc;
369
370 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
371}
372
373static int spi_probe(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376 struct spi_device *spi = to_spi_device(dev);
377 int ret;
378
379 ret = of_clk_set_defaults(dev->of_node, false);
380 if (ret)
381 return ret;
382
383 if (dev->of_node) {
384 spi->irq = of_irq_get(dev->of_node, 0);
385 if (spi->irq == -EPROBE_DEFER)
386 return -EPROBE_DEFER;
387 if (spi->irq < 0)
388 spi->irq = 0;
389 }
390
391 ret = dev_pm_domain_attach(dev, true);
392 if (ret)
393 return ret;
394
395 if (sdrv->probe) {
396 ret = sdrv->probe(spi);
397 if (ret)
398 dev_pm_domain_detach(dev, true);
399 }
400
401 return ret;
402}
403
404static int spi_remove(struct device *dev)
405{
406 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
407
408 if (sdrv->remove) {
409 int ret;
410
411 ret = sdrv->remove(to_spi_device(dev));
412 if (ret)
413 dev_warn(dev,
414 "Failed to unbind driver (%pe), ignoring\n",
415 ERR_PTR(ret));
416 }
417
418 dev_pm_domain_detach(dev, true);
419
420 return 0;
421}
422
423static void spi_shutdown(struct device *dev)
424{
425 if (dev->driver) {
426 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
427
428 if (sdrv->shutdown)
429 sdrv->shutdown(to_spi_device(dev));
430 }
431}
432
433struct bus_type spi_bus_type = {
434 .name = "spi",
435 .dev_groups = spi_dev_groups,
436 .match = spi_match_device,
437 .uevent = spi_uevent,
438 .probe = spi_probe,
439 .remove = spi_remove,
440 .shutdown = spi_shutdown,
441};
442EXPORT_SYMBOL_GPL(spi_bus_type);
443
444/**
445 * __spi_register_driver - register a SPI driver
446 * @owner: owner module of the driver to register
447 * @sdrv: the driver to register
448 * Context: can sleep
449 *
450 * Return: zero on success, else a negative error code.
451 */
452int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
453{
454 sdrv->driver.owner = owner;
455 sdrv->driver.bus = &spi_bus_type;
456 return driver_register(&sdrv->driver);
457}
458EXPORT_SYMBOL_GPL(__spi_register_driver);
459
460/*-------------------------------------------------------------------------*/
461
462/* SPI devices should normally not be created by SPI device drivers; that
463 * would make them board-specific. Similarly with SPI controller drivers.
464 * Device registration normally goes into like arch/.../mach.../board-YYY.c
465 * with other readonly (flashable) information about mainboard devices.
466 */
467
468struct boardinfo {
469 struct list_head list;
470 struct spi_board_info board_info;
471};
472
473static LIST_HEAD(board_list);
474static LIST_HEAD(spi_controller_list);
475
476/*
477 * Used to protect add/del operation for board_info list and
478 * spi_controller list, and their matching process
479 * also used to protect object of type struct idr
480 */
481static DEFINE_MUTEX(board_lock);
482
483/**
484 * spi_alloc_device - Allocate a new SPI device
485 * @ctlr: Controller to which device is connected
486 * Context: can sleep
487 *
488 * Allows a driver to allocate and initialize a spi_device without
489 * registering it immediately. This allows a driver to directly
490 * fill the spi_device with device parameters before calling
491 * spi_add_device() on it.
492 *
493 * Caller is responsible to call spi_add_device() on the returned
494 * spi_device structure to add it to the SPI controller. If the caller
495 * needs to discard the spi_device without adding it, then it should
496 * call spi_dev_put() on it.
497 *
498 * Return: a pointer to the new device, or NULL.
499 */
500struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
501{
502 struct spi_device *spi;
503
504 if (!spi_controller_get(ctlr))
505 return NULL;
506
507 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
508 if (!spi) {
509 spi_controller_put(ctlr);
510 return NULL;
511 }
512
513 spi->master = spi->controller = ctlr;
514 spi->dev.parent = &ctlr->dev;
515 spi->dev.bus = &spi_bus_type;
516 spi->dev.release = spidev_release;
517 spi->cs_gpio = -ENOENT;
518 spi->mode = ctlr->buswidth_override_bits;
519
520 spin_lock_init(&spi->statistics.lock);
521
522 device_initialize(&spi->dev);
523 return spi;
524}
525EXPORT_SYMBOL_GPL(spi_alloc_device);
526
527static void spi_dev_set_name(struct spi_device *spi)
528{
529 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
530
531 if (adev) {
532 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
533 return;
534 }
535
536 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
537 spi->chip_select);
538}
539
540static int spi_dev_check(struct device *dev, void *data)
541{
542 struct spi_device *spi = to_spi_device(dev);
543 struct spi_device *new_spi = data;
544
545 if (spi->controller == new_spi->controller &&
546 spi->chip_select == new_spi->chip_select)
547 return -EBUSY;
548 return 0;
549}
550
551static void spi_cleanup(struct spi_device *spi)
552{
553 if (spi->controller->cleanup)
554 spi->controller->cleanup(spi);
555}
556
557static int __spi_add_device(struct spi_device *spi)
558{
559 struct spi_controller *ctlr = spi->controller;
560 struct device *dev = ctlr->dev.parent;
561 int status;
562
563 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
564 if (status) {
565 dev_err(dev, "chipselect %d already in use\n",
566 spi->chip_select);
567 return status;
568 }
569
570 /* Controller may unregister concurrently */
571 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
572 !device_is_registered(&ctlr->dev)) {
573 return -ENODEV;
574 }
575
576 /* Descriptors take precedence */
577 if (ctlr->cs_gpiods)
578 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
579 else if (ctlr->cs_gpios)
580 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
581
582 /* Drivers may modify this initial i/o setup, but will
583 * normally rely on the device being setup. Devices
584 * using SPI_CS_HIGH can't coexist well otherwise...
585 */
586 status = spi_setup(spi);
587 if (status < 0) {
588 dev_err(dev, "can't setup %s, status %d\n",
589 dev_name(&spi->dev), status);
590 return status;
591 }
592
593 /* Device may be bound to an active driver when this returns */
594 status = device_add(&spi->dev);
595 if (status < 0) {
596 dev_err(dev, "can't add %s, status %d\n",
597 dev_name(&spi->dev), status);
598 spi_cleanup(spi);
599 } else {
600 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
601 }
602
603 return status;
604}
605
606/**
607 * spi_add_device - Add spi_device allocated with spi_alloc_device
608 * @spi: spi_device to register
609 *
610 * Companion function to spi_alloc_device. Devices allocated with
611 * spi_alloc_device can be added onto the spi bus with this function.
612 *
613 * Return: 0 on success; negative errno on failure
614 */
615int spi_add_device(struct spi_device *spi)
616{
617 struct spi_controller *ctlr = spi->controller;
618 struct device *dev = ctlr->dev.parent;
619 int status;
620
621 /* Chipselects are numbered 0..max; validate. */
622 if (spi->chip_select >= ctlr->num_chipselect) {
623 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
624 ctlr->num_chipselect);
625 return -EINVAL;
626 }
627
628 /* Set the bus ID string */
629 spi_dev_set_name(spi);
630
631 /* We need to make sure there's no other device with this
632 * chipselect **BEFORE** we call setup(), else we'll trash
633 * its configuration. Lock against concurrent add() calls.
634 */
635 mutex_lock(&ctlr->add_lock);
636 status = __spi_add_device(spi);
637 mutex_unlock(&ctlr->add_lock);
638 return status;
639}
640EXPORT_SYMBOL_GPL(spi_add_device);
641
642static int spi_add_device_locked(struct spi_device *spi)
643{
644 struct spi_controller *ctlr = spi->controller;
645 struct device *dev = ctlr->dev.parent;
646
647 /* Chipselects are numbered 0..max; validate. */
648 if (spi->chip_select >= ctlr->num_chipselect) {
649 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
650 ctlr->num_chipselect);
651 return -EINVAL;
652 }
653
654 /* Set the bus ID string */
655 spi_dev_set_name(spi);
656
657 WARN_ON(!mutex_is_locked(&ctlr->add_lock));
658 return __spi_add_device(spi);
659}
660
661/**
662 * spi_new_device - instantiate one new SPI device
663 * @ctlr: Controller to which device is connected
664 * @chip: Describes the SPI device
665 * Context: can sleep
666 *
667 * On typical mainboards, this is purely internal; and it's not needed
668 * after board init creates the hard-wired devices. Some development
669 * platforms may not be able to use spi_register_board_info though, and
670 * this is exported so that for example a USB or parport based adapter
671 * driver could add devices (which it would learn about out-of-band).
672 *
673 * Return: the new device, or NULL.
674 */
675struct spi_device *spi_new_device(struct spi_controller *ctlr,
676 struct spi_board_info *chip)
677{
678 struct spi_device *proxy;
679 int status;
680
681 /* NOTE: caller did any chip->bus_num checks necessary.
682 *
683 * Also, unless we change the return value convention to use
684 * error-or-pointer (not NULL-or-pointer), troubleshootability
685 * suggests syslogged diagnostics are best here (ugh).
686 */
687
688 proxy = spi_alloc_device(ctlr);
689 if (!proxy)
690 return NULL;
691
692 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
693
694 proxy->chip_select = chip->chip_select;
695 proxy->max_speed_hz = chip->max_speed_hz;
696 proxy->mode = chip->mode;
697 proxy->irq = chip->irq;
698 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
699 proxy->dev.platform_data = (void *) chip->platform_data;
700 proxy->controller_data = chip->controller_data;
701 proxy->controller_state = NULL;
702
703 if (chip->swnode) {
704 status = device_add_software_node(&proxy->dev, chip->swnode);
705 if (status) {
706 dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",
707 chip->modalias, status);
708 goto err_dev_put;
709 }
710 }
711
712 status = spi_add_device(proxy);
713 if (status < 0)
714 goto err_dev_put;
715
716 return proxy;
717
718err_dev_put:
719 device_remove_software_node(&proxy->dev);
720 spi_dev_put(proxy);
721 return NULL;
722}
723EXPORT_SYMBOL_GPL(spi_new_device);
724
725/**
726 * spi_unregister_device - unregister a single SPI device
727 * @spi: spi_device to unregister
728 *
729 * Start making the passed SPI device vanish. Normally this would be handled
730 * by spi_unregister_controller().
731 */
732void spi_unregister_device(struct spi_device *spi)
733{
734 if (!spi)
735 return;
736
737 if (spi->dev.of_node) {
738 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
739 of_node_put(spi->dev.of_node);
740 }
741 if (ACPI_COMPANION(&spi->dev))
742 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
743 device_remove_software_node(&spi->dev);
744 device_del(&spi->dev);
745 spi_cleanup(spi);
746 put_device(&spi->dev);
747}
748EXPORT_SYMBOL_GPL(spi_unregister_device);
749
750static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
751 struct spi_board_info *bi)
752{
753 struct spi_device *dev;
754
755 if (ctlr->bus_num != bi->bus_num)
756 return;
757
758 dev = spi_new_device(ctlr, bi);
759 if (!dev)
760 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
761 bi->modalias);
762}
763
764/**
765 * spi_register_board_info - register SPI devices for a given board
766 * @info: array of chip descriptors
767 * @n: how many descriptors are provided
768 * Context: can sleep
769 *
770 * Board-specific early init code calls this (probably during arch_initcall)
771 * with segments of the SPI device table. Any device nodes are created later,
772 * after the relevant parent SPI controller (bus_num) is defined. We keep
773 * this table of devices forever, so that reloading a controller driver will
774 * not make Linux forget about these hard-wired devices.
775 *
776 * Other code can also call this, e.g. a particular add-on board might provide
777 * SPI devices through its expansion connector, so code initializing that board
778 * would naturally declare its SPI devices.
779 *
780 * The board info passed can safely be __initdata ... but be careful of
781 * any embedded pointers (platform_data, etc), they're copied as-is.
782 *
783 * Return: zero on success, else a negative error code.
784 */
785int spi_register_board_info(struct spi_board_info const *info, unsigned n)
786{
787 struct boardinfo *bi;
788 int i;
789
790 if (!n)
791 return 0;
792
793 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
794 if (!bi)
795 return -ENOMEM;
796
797 for (i = 0; i < n; i++, bi++, info++) {
798 struct spi_controller *ctlr;
799
800 memcpy(&bi->board_info, info, sizeof(*info));
801
802 mutex_lock(&board_lock);
803 list_add_tail(&bi->list, &board_list);
804 list_for_each_entry(ctlr, &spi_controller_list, list)
805 spi_match_controller_to_boardinfo(ctlr,
806 &bi->board_info);
807 mutex_unlock(&board_lock);
808 }
809
810 return 0;
811}
812
813/*-------------------------------------------------------------------------*/
814
815static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
816{
817 bool activate = enable;
818
819 /*
820 * Avoid calling into the driver (or doing delays) if the chip select
821 * isn't actually changing from the last time this was called.
822 */
823 if (!force && (spi->controller->last_cs_enable == enable) &&
824 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
825 return;
826
827 trace_spi_set_cs(spi, activate);
828
829 spi->controller->last_cs_enable = enable;
830 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
831
832 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
833 !spi->controller->set_cs_timing) {
834 if (activate)
835 spi_delay_exec(&spi->controller->cs_setup, NULL);
836 else
837 spi_delay_exec(&spi->controller->cs_hold, NULL);
838 }
839
840 if (spi->mode & SPI_CS_HIGH)
841 enable = !enable;
842
843 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
844 if (!(spi->mode & SPI_NO_CS)) {
845 if (spi->cs_gpiod) {
846 /*
847 * Historically ACPI has no means of the GPIO polarity and
848 * thus the SPISerialBus() resource defines it on the per-chip
849 * basis. In order to avoid a chain of negations, the GPIO
850 * polarity is considered being Active High. Even for the cases
851 * when _DSD() is involved (in the updated versions of ACPI)
852 * the GPIO CS polarity must be defined Active High to avoid
853 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
854 * into account.
855 */
856 if (has_acpi_companion(&spi->dev))
857 gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
858 else
859 /* Polarity handled by GPIO library */
860 gpiod_set_value_cansleep(spi->cs_gpiod, activate);
861 } else {
862 /*
863 * invert the enable line, as active low is
864 * default for SPI.
865 */
866 gpio_set_value_cansleep(spi->cs_gpio, !enable);
867 }
868 }
869 /* Some SPI masters need both GPIO CS & slave_select */
870 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
871 spi->controller->set_cs)
872 spi->controller->set_cs(spi, !enable);
873 } else if (spi->controller->set_cs) {
874 spi->controller->set_cs(spi, !enable);
875 }
876
877 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio) ||
878 !spi->controller->set_cs_timing) {
879 if (!activate)
880 spi_delay_exec(&spi->controller->cs_inactive, NULL);
881 }
882}
883
884#ifdef CONFIG_HAS_DMA
885int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
886 struct sg_table *sgt, void *buf, size_t len,
887 enum dma_data_direction dir)
888{
889 const bool vmalloced_buf = is_vmalloc_addr(buf);
890 unsigned int max_seg_size = dma_get_max_seg_size(dev);
891#ifdef CONFIG_HIGHMEM
892 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
893 (unsigned long)buf < (PKMAP_BASE +
894 (LAST_PKMAP * PAGE_SIZE)));
895#else
896 const bool kmap_buf = false;
897#endif
898 int desc_len;
899 int sgs;
900 struct page *vm_page;
901 struct scatterlist *sg;
902 void *sg_buf;
903 size_t min;
904 int i, ret;
905
906 if (vmalloced_buf || kmap_buf) {
907 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
908 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
909 } else if (virt_addr_valid(buf)) {
910 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
911 sgs = DIV_ROUND_UP(len, desc_len);
912 } else {
913 return -EINVAL;
914 }
915
916 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
917 if (ret != 0)
918 return ret;
919
920 sg = &sgt->sgl[0];
921 for (i = 0; i < sgs; i++) {
922
923 if (vmalloced_buf || kmap_buf) {
924 /*
925 * Next scatterlist entry size is the minimum between
926 * the desc_len and the remaining buffer length that
927 * fits in a page.
928 */
929 min = min_t(size_t, desc_len,
930 min_t(size_t, len,
931 PAGE_SIZE - offset_in_page(buf)));
932 if (vmalloced_buf)
933 vm_page = vmalloc_to_page(buf);
934 else
935 vm_page = kmap_to_page(buf);
936 if (!vm_page) {
937 sg_free_table(sgt);
938 return -ENOMEM;
939 }
940 sg_set_page(sg, vm_page,
941 min, offset_in_page(buf));
942 } else {
943 min = min_t(size_t, len, desc_len);
944 sg_buf = buf;
945 sg_set_buf(sg, sg_buf, min);
946 }
947
948 buf += min;
949 len -= min;
950 sg = sg_next(sg);
951 }
952
953 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
954 if (!ret)
955 ret = -ENOMEM;
956 if (ret < 0) {
957 sg_free_table(sgt);
958 return ret;
959 }
960
961 sgt->nents = ret;
962
963 return 0;
964}
965
966void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
967 struct sg_table *sgt, enum dma_data_direction dir)
968{
969 if (sgt->orig_nents) {
970 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
971 sg_free_table(sgt);
972 }
973}
974
975static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
976{
977 struct device *tx_dev, *rx_dev;
978 struct spi_transfer *xfer;
979 int ret;
980
981 if (!ctlr->can_dma)
982 return 0;
983
984 if (ctlr->dma_tx)
985 tx_dev = ctlr->dma_tx->device->dev;
986 else if (ctlr->dma_map_dev)
987 tx_dev = ctlr->dma_map_dev;
988 else
989 tx_dev = ctlr->dev.parent;
990
991 if (ctlr->dma_rx)
992 rx_dev = ctlr->dma_rx->device->dev;
993 else if (ctlr->dma_map_dev)
994 rx_dev = ctlr->dma_map_dev;
995 else
996 rx_dev = ctlr->dev.parent;
997
998 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
999 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1000 continue;
1001
1002 if (xfer->tx_buf != NULL) {
1003 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
1004 (void *)xfer->tx_buf, xfer->len,
1005 DMA_TO_DEVICE);
1006 if (ret != 0)
1007 return ret;
1008 }
1009
1010 if (xfer->rx_buf != NULL) {
1011 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
1012 xfer->rx_buf, xfer->len,
1013 DMA_FROM_DEVICE);
1014 if (ret != 0) {
1015 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
1016 DMA_TO_DEVICE);
1017 return ret;
1018 }
1019 }
1020 }
1021
1022 ctlr->cur_msg_mapped = true;
1023
1024 return 0;
1025}
1026
1027static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
1028{
1029 struct spi_transfer *xfer;
1030 struct device *tx_dev, *rx_dev;
1031
1032 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
1033 return 0;
1034
1035 if (ctlr->dma_tx)
1036 tx_dev = ctlr->dma_tx->device->dev;
1037 else
1038 tx_dev = ctlr->dev.parent;
1039
1040 if (ctlr->dma_rx)
1041 rx_dev = ctlr->dma_rx->device->dev;
1042 else
1043 rx_dev = ctlr->dev.parent;
1044
1045 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1046 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1047 continue;
1048
1049 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1050 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1051 }
1052
1053 ctlr->cur_msg_mapped = false;
1054
1055 return 0;
1056}
1057#else /* !CONFIG_HAS_DMA */
1058static inline int __spi_map_msg(struct spi_controller *ctlr,
1059 struct spi_message *msg)
1060{
1061 return 0;
1062}
1063
1064static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1065 struct spi_message *msg)
1066{
1067 return 0;
1068}
1069#endif /* !CONFIG_HAS_DMA */
1070
1071static inline int spi_unmap_msg(struct spi_controller *ctlr,
1072 struct spi_message *msg)
1073{
1074 struct spi_transfer *xfer;
1075
1076 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1077 /*
1078 * Restore the original value of tx_buf or rx_buf if they are
1079 * NULL.
1080 */
1081 if (xfer->tx_buf == ctlr->dummy_tx)
1082 xfer->tx_buf = NULL;
1083 if (xfer->rx_buf == ctlr->dummy_rx)
1084 xfer->rx_buf = NULL;
1085 }
1086
1087 return __spi_unmap_msg(ctlr, msg);
1088}
1089
1090static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1091{
1092 struct spi_transfer *xfer;
1093 void *tmp;
1094 unsigned int max_tx, max_rx;
1095
1096 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1097 && !(msg->spi->mode & SPI_3WIRE)) {
1098 max_tx = 0;
1099 max_rx = 0;
1100
1101 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1102 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1103 !xfer->tx_buf)
1104 max_tx = max(xfer->len, max_tx);
1105 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1106 !xfer->rx_buf)
1107 max_rx = max(xfer->len, max_rx);
1108 }
1109
1110 if (max_tx) {
1111 tmp = krealloc(ctlr->dummy_tx, max_tx,
1112 GFP_KERNEL | GFP_DMA);
1113 if (!tmp)
1114 return -ENOMEM;
1115 ctlr->dummy_tx = tmp;
1116 memset(tmp, 0, max_tx);
1117 }
1118
1119 if (max_rx) {
1120 tmp = krealloc(ctlr->dummy_rx, max_rx,
1121 GFP_KERNEL | GFP_DMA);
1122 if (!tmp)
1123 return -ENOMEM;
1124 ctlr->dummy_rx = tmp;
1125 }
1126
1127 if (max_tx || max_rx) {
1128 list_for_each_entry(xfer, &msg->transfers,
1129 transfer_list) {
1130 if (!xfer->len)
1131 continue;
1132 if (!xfer->tx_buf)
1133 xfer->tx_buf = ctlr->dummy_tx;
1134 if (!xfer->rx_buf)
1135 xfer->rx_buf = ctlr->dummy_rx;
1136 }
1137 }
1138 }
1139
1140 return __spi_map_msg(ctlr, msg);
1141}
1142
1143static int spi_transfer_wait(struct spi_controller *ctlr,
1144 struct spi_message *msg,
1145 struct spi_transfer *xfer)
1146{
1147 struct spi_statistics *statm = &ctlr->statistics;
1148 struct spi_statistics *stats = &msg->spi->statistics;
1149 u32 speed_hz = xfer->speed_hz;
1150 unsigned long long ms;
1151
1152 if (spi_controller_is_slave(ctlr)) {
1153 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1154 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1155 return -EINTR;
1156 }
1157 } else {
1158 if (!speed_hz)
1159 speed_hz = 100000;
1160
1161 /*
1162 * For each byte we wait for 8 cycles of the SPI clock.
1163 * Since speed is defined in Hz and we want milliseconds,
1164 * use respective multiplier, but before the division,
1165 * otherwise we may get 0 for short transfers.
1166 */
1167 ms = 8LL * MSEC_PER_SEC * xfer->len;
1168 do_div(ms, speed_hz);
1169
1170 /*
1171 * Increase it twice and add 200 ms tolerance, use
1172 * predefined maximum in case of overflow.
1173 */
1174 ms += ms + 200;
1175 if (ms > UINT_MAX)
1176 ms = UINT_MAX;
1177
1178 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1179 msecs_to_jiffies(ms));
1180
1181 if (ms == 0) {
1182 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1183 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1184 dev_err(&msg->spi->dev,
1185 "SPI transfer timed out\n");
1186 return -ETIMEDOUT;
1187 }
1188 }
1189
1190 return 0;
1191}
1192
1193static void _spi_transfer_delay_ns(u32 ns)
1194{
1195 if (!ns)
1196 return;
1197 if (ns <= NSEC_PER_USEC) {
1198 ndelay(ns);
1199 } else {
1200 u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);
1201
1202 if (us <= 10)
1203 udelay(us);
1204 else
1205 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1206 }
1207}
1208
1209int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1210{
1211 u32 delay = _delay->value;
1212 u32 unit = _delay->unit;
1213 u32 hz;
1214
1215 if (!delay)
1216 return 0;
1217
1218 switch (unit) {
1219 case SPI_DELAY_UNIT_USECS:
1220 delay *= NSEC_PER_USEC;
1221 break;
1222 case SPI_DELAY_UNIT_NSECS:
1223 /* Nothing to do here */
1224 break;
1225 case SPI_DELAY_UNIT_SCK:
1226 /* clock cycles need to be obtained from spi_transfer */
1227 if (!xfer)
1228 return -EINVAL;
1229 /*
1230 * If there is unknown effective speed, approximate it
1231 * by underestimating with half of the requested hz.
1232 */
1233 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1234 if (!hz)
1235 return -EINVAL;
1236
1237 /* Convert delay to nanoseconds */
1238 delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);
1239 break;
1240 default:
1241 return -EINVAL;
1242 }
1243
1244 return delay;
1245}
1246EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1247
1248int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1249{
1250 int delay;
1251
1252 might_sleep();
1253
1254 if (!_delay)
1255 return -EINVAL;
1256
1257 delay = spi_delay_to_ns(_delay, xfer);
1258 if (delay < 0)
1259 return delay;
1260
1261 _spi_transfer_delay_ns(delay);
1262
1263 return 0;
1264}
1265EXPORT_SYMBOL_GPL(spi_delay_exec);
1266
1267static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1268 struct spi_transfer *xfer)
1269{
1270 u32 default_delay_ns = 10 * NSEC_PER_USEC;
1271 u32 delay = xfer->cs_change_delay.value;
1272 u32 unit = xfer->cs_change_delay.unit;
1273 int ret;
1274
1275 /* return early on "fast" mode - for everything but USECS */
1276 if (!delay) {
1277 if (unit == SPI_DELAY_UNIT_USECS)
1278 _spi_transfer_delay_ns(default_delay_ns);
1279 return;
1280 }
1281
1282 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1283 if (ret) {
1284 dev_err_once(&msg->spi->dev,
1285 "Use of unsupported delay unit %i, using default of %luus\n",
1286 unit, default_delay_ns / NSEC_PER_USEC);
1287 _spi_transfer_delay_ns(default_delay_ns);
1288 }
1289}
1290
1291/*
1292 * spi_transfer_one_message - Default implementation of transfer_one_message()
1293 *
1294 * This is a standard implementation of transfer_one_message() for
1295 * drivers which implement a transfer_one() operation. It provides
1296 * standard handling of delays and chip select management.
1297 */
1298static int spi_transfer_one_message(struct spi_controller *ctlr,
1299 struct spi_message *msg)
1300{
1301 struct spi_transfer *xfer;
1302 bool keep_cs = false;
1303 int ret = 0;
1304 struct spi_statistics *statm = &ctlr->statistics;
1305 struct spi_statistics *stats = &msg->spi->statistics;
1306
1307 spi_set_cs(msg->spi, true, false);
1308
1309 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1310 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1311
1312 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1313 trace_spi_transfer_start(msg, xfer);
1314
1315 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1316 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1317
1318 if (!ctlr->ptp_sts_supported) {
1319 xfer->ptp_sts_word_pre = 0;
1320 ptp_read_system_prets(xfer->ptp_sts);
1321 }
1322
1323 if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1324 reinit_completion(&ctlr->xfer_completion);
1325
1326fallback_pio:
1327 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1328 if (ret < 0) {
1329 if (ctlr->cur_msg_mapped &&
1330 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1331 __spi_unmap_msg(ctlr, msg);
1332 ctlr->fallback = true;
1333 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1334 goto fallback_pio;
1335 }
1336
1337 SPI_STATISTICS_INCREMENT_FIELD(statm,
1338 errors);
1339 SPI_STATISTICS_INCREMENT_FIELD(stats,
1340 errors);
1341 dev_err(&msg->spi->dev,
1342 "SPI transfer failed: %d\n", ret);
1343 goto out;
1344 }
1345
1346 if (ret > 0) {
1347 ret = spi_transfer_wait(ctlr, msg, xfer);
1348 if (ret < 0)
1349 msg->status = ret;
1350 }
1351 } else {
1352 if (xfer->len)
1353 dev_err(&msg->spi->dev,
1354 "Bufferless transfer has length %u\n",
1355 xfer->len);
1356 }
1357
1358 if (!ctlr->ptp_sts_supported) {
1359 ptp_read_system_postts(xfer->ptp_sts);
1360 xfer->ptp_sts_word_post = xfer->len;
1361 }
1362
1363 trace_spi_transfer_stop(msg, xfer);
1364
1365 if (msg->status != -EINPROGRESS)
1366 goto out;
1367
1368 spi_transfer_delay_exec(xfer);
1369
1370 if (xfer->cs_change) {
1371 if (list_is_last(&xfer->transfer_list,
1372 &msg->transfers)) {
1373 keep_cs = true;
1374 } else {
1375 spi_set_cs(msg->spi, false, false);
1376 _spi_transfer_cs_change_delay(msg, xfer);
1377 spi_set_cs(msg->spi, true, false);
1378 }
1379 }
1380
1381 msg->actual_length += xfer->len;
1382 }
1383
1384out:
1385 if (ret != 0 || !keep_cs)
1386 spi_set_cs(msg->spi, false, false);
1387
1388 if (msg->status == -EINPROGRESS)
1389 msg->status = ret;
1390
1391 if (msg->status && ctlr->handle_err)
1392 ctlr->handle_err(ctlr, msg);
1393
1394 spi_finalize_current_message(ctlr);
1395
1396 return ret;
1397}
1398
1399/**
1400 * spi_finalize_current_transfer - report completion of a transfer
1401 * @ctlr: the controller reporting completion
1402 *
1403 * Called by SPI drivers using the core transfer_one_message()
1404 * implementation to notify it that the current interrupt driven
1405 * transfer has finished and the next one may be scheduled.
1406 */
1407void spi_finalize_current_transfer(struct spi_controller *ctlr)
1408{
1409 complete(&ctlr->xfer_completion);
1410}
1411EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1412
1413static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1414{
1415 if (ctlr->auto_runtime_pm) {
1416 pm_runtime_mark_last_busy(ctlr->dev.parent);
1417 pm_runtime_put_autosuspend(ctlr->dev.parent);
1418 }
1419}
1420
1421/**
1422 * __spi_pump_messages - function which processes spi message queue
1423 * @ctlr: controller to process queue for
1424 * @in_kthread: true if we are in the context of the message pump thread
1425 *
1426 * This function checks if there is any spi message in the queue that
1427 * needs processing and if so call out to the driver to initialize hardware
1428 * and transfer each message.
1429 *
1430 * Note that it is called both from the kthread itself and also from
1431 * inside spi_sync(); the queue extraction handling at the top of the
1432 * function should deal with this safely.
1433 */
1434static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1435{
1436 struct spi_transfer *xfer;
1437 struct spi_message *msg;
1438 bool was_busy = false;
1439 unsigned long flags;
1440 int ret;
1441
1442 /* Lock queue */
1443 spin_lock_irqsave(&ctlr->queue_lock, flags);
1444
1445 /* Make sure we are not already running a message */
1446 if (ctlr->cur_msg) {
1447 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1448 return;
1449 }
1450
1451 /* If another context is idling the device then defer */
1452 if (ctlr->idling) {
1453 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1454 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1455 return;
1456 }
1457
1458 /* Check if the queue is idle */
1459 if (list_empty(&ctlr->queue) || !ctlr->running) {
1460 if (!ctlr->busy) {
1461 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1462 return;
1463 }
1464
1465 /* Defer any non-atomic teardown to the thread */
1466 if (!in_kthread) {
1467 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1468 !ctlr->unprepare_transfer_hardware) {
1469 spi_idle_runtime_pm(ctlr);
1470 ctlr->busy = false;
1471 trace_spi_controller_idle(ctlr);
1472 } else {
1473 kthread_queue_work(ctlr->kworker,
1474 &ctlr->pump_messages);
1475 }
1476 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1477 return;
1478 }
1479
1480 ctlr->busy = false;
1481 ctlr->idling = true;
1482 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1483
1484 kfree(ctlr->dummy_rx);
1485 ctlr->dummy_rx = NULL;
1486 kfree(ctlr->dummy_tx);
1487 ctlr->dummy_tx = NULL;
1488 if (ctlr->unprepare_transfer_hardware &&
1489 ctlr->unprepare_transfer_hardware(ctlr))
1490 dev_err(&ctlr->dev,
1491 "failed to unprepare transfer hardware\n");
1492 spi_idle_runtime_pm(ctlr);
1493 trace_spi_controller_idle(ctlr);
1494
1495 spin_lock_irqsave(&ctlr->queue_lock, flags);
1496 ctlr->idling = false;
1497 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1498 return;
1499 }
1500
1501 /* Extract head of queue */
1502 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1503 ctlr->cur_msg = msg;
1504
1505 list_del_init(&msg->queue);
1506 if (ctlr->busy)
1507 was_busy = true;
1508 else
1509 ctlr->busy = true;
1510 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1511
1512 mutex_lock(&ctlr->io_mutex);
1513
1514 if (!was_busy && ctlr->auto_runtime_pm) {
1515 ret = pm_runtime_get_sync(ctlr->dev.parent);
1516 if (ret < 0) {
1517 pm_runtime_put_noidle(ctlr->dev.parent);
1518 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1519 ret);
1520 mutex_unlock(&ctlr->io_mutex);
1521 return;
1522 }
1523 }
1524
1525 if (!was_busy)
1526 trace_spi_controller_busy(ctlr);
1527
1528 if (!was_busy && ctlr->prepare_transfer_hardware) {
1529 ret = ctlr->prepare_transfer_hardware(ctlr);
1530 if (ret) {
1531 dev_err(&ctlr->dev,
1532 "failed to prepare transfer hardware: %d\n",
1533 ret);
1534
1535 if (ctlr->auto_runtime_pm)
1536 pm_runtime_put(ctlr->dev.parent);
1537
1538 msg->status = ret;
1539 spi_finalize_current_message(ctlr);
1540
1541 mutex_unlock(&ctlr->io_mutex);
1542 return;
1543 }
1544 }
1545
1546 trace_spi_message_start(msg);
1547
1548 if (ctlr->prepare_message) {
1549 ret = ctlr->prepare_message(ctlr, msg);
1550 if (ret) {
1551 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1552 ret);
1553 msg->status = ret;
1554 spi_finalize_current_message(ctlr);
1555 goto out;
1556 }
1557 ctlr->cur_msg_prepared = true;
1558 }
1559
1560 ret = spi_map_msg(ctlr, msg);
1561 if (ret) {
1562 msg->status = ret;
1563 spi_finalize_current_message(ctlr);
1564 goto out;
1565 }
1566
1567 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1568 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1569 xfer->ptp_sts_word_pre = 0;
1570 ptp_read_system_prets(xfer->ptp_sts);
1571 }
1572 }
1573
1574 ret = ctlr->transfer_one_message(ctlr, msg);
1575 if (ret) {
1576 dev_err(&ctlr->dev,
1577 "failed to transfer one message from queue\n");
1578 goto out;
1579 }
1580
1581out:
1582 mutex_unlock(&ctlr->io_mutex);
1583
1584 /* Prod the scheduler in case transfer_one() was busy waiting */
1585 if (!ret)
1586 cond_resched();
1587}
1588
1589/**
1590 * spi_pump_messages - kthread work function which processes spi message queue
1591 * @work: pointer to kthread work struct contained in the controller struct
1592 */
1593static void spi_pump_messages(struct kthread_work *work)
1594{
1595 struct spi_controller *ctlr =
1596 container_of(work, struct spi_controller, pump_messages);
1597
1598 __spi_pump_messages(ctlr, true);
1599}
1600
1601/**
1602 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1603 * TX timestamp for the requested byte from the SPI
1604 * transfer. The frequency with which this function
1605 * must be called (once per word, once for the whole
1606 * transfer, once per batch of words etc) is arbitrary
1607 * as long as the @tx buffer offset is greater than or
1608 * equal to the requested byte at the time of the
1609 * call. The timestamp is only taken once, at the
1610 * first such call. It is assumed that the driver
1611 * advances its @tx buffer pointer monotonically.
1612 * @ctlr: Pointer to the spi_controller structure of the driver
1613 * @xfer: Pointer to the transfer being timestamped
1614 * @progress: How many words (not bytes) have been transferred so far
1615 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1616 * transfer, for less jitter in time measurement. Only compatible
1617 * with PIO drivers. If true, must follow up with
1618 * spi_take_timestamp_post or otherwise system will crash.
1619 * WARNING: for fully predictable results, the CPU frequency must
1620 * also be under control (governor).
1621 */
1622void spi_take_timestamp_pre(struct spi_controller *ctlr,
1623 struct spi_transfer *xfer,
1624 size_t progress, bool irqs_off)
1625{
1626 if (!xfer->ptp_sts)
1627 return;
1628
1629 if (xfer->timestamped)
1630 return;
1631
1632 if (progress > xfer->ptp_sts_word_pre)
1633 return;
1634
1635 /* Capture the resolution of the timestamp */
1636 xfer->ptp_sts_word_pre = progress;
1637
1638 if (irqs_off) {
1639 local_irq_save(ctlr->irq_flags);
1640 preempt_disable();
1641 }
1642
1643 ptp_read_system_prets(xfer->ptp_sts);
1644}
1645EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1646
1647/**
1648 * spi_take_timestamp_post - helper for drivers to collect the end of the
1649 * TX timestamp for the requested byte from the SPI
1650 * transfer. Can be called with an arbitrary
1651 * frequency: only the first call where @tx exceeds
1652 * or is equal to the requested word will be
1653 * timestamped.
1654 * @ctlr: Pointer to the spi_controller structure of the driver
1655 * @xfer: Pointer to the transfer being timestamped
1656 * @progress: How many words (not bytes) have been transferred so far
1657 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1658 */
1659void spi_take_timestamp_post(struct spi_controller *ctlr,
1660 struct spi_transfer *xfer,
1661 size_t progress, bool irqs_off)
1662{
1663 if (!xfer->ptp_sts)
1664 return;
1665
1666 if (xfer->timestamped)
1667 return;
1668
1669 if (progress < xfer->ptp_sts_word_post)
1670 return;
1671
1672 ptp_read_system_postts(xfer->ptp_sts);
1673
1674 if (irqs_off) {
1675 local_irq_restore(ctlr->irq_flags);
1676 preempt_enable();
1677 }
1678
1679 /* Capture the resolution of the timestamp */
1680 xfer->ptp_sts_word_post = progress;
1681
1682 xfer->timestamped = true;
1683}
1684EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1685
1686/**
1687 * spi_set_thread_rt - set the controller to pump at realtime priority
1688 * @ctlr: controller to boost priority of
1689 *
1690 * This can be called because the controller requested realtime priority
1691 * (by setting the ->rt value before calling spi_register_controller()) or
1692 * because a device on the bus said that its transfers needed realtime
1693 * priority.
1694 *
1695 * NOTE: at the moment if any device on a bus says it needs realtime then
1696 * the thread will be at realtime priority for all transfers on that
1697 * controller. If this eventually becomes a problem we may see if we can
1698 * find a way to boost the priority only temporarily during relevant
1699 * transfers.
1700 */
1701static void spi_set_thread_rt(struct spi_controller *ctlr)
1702{
1703 dev_info(&ctlr->dev,
1704 "will run message pump with realtime priority\n");
1705 sched_set_fifo(ctlr->kworker->task);
1706}
1707
1708static int spi_init_queue(struct spi_controller *ctlr)
1709{
1710 ctlr->running = false;
1711 ctlr->busy = false;
1712
1713 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1714 if (IS_ERR(ctlr->kworker)) {
1715 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1716 return PTR_ERR(ctlr->kworker);
1717 }
1718
1719 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1720
1721 /*
1722 * Controller config will indicate if this controller should run the
1723 * message pump with high (realtime) priority to reduce the transfer
1724 * latency on the bus by minimising the delay between a transfer
1725 * request and the scheduling of the message pump thread. Without this
1726 * setting the message pump thread will remain at default priority.
1727 */
1728 if (ctlr->rt)
1729 spi_set_thread_rt(ctlr);
1730
1731 return 0;
1732}
1733
1734/**
1735 * spi_get_next_queued_message() - called by driver to check for queued
1736 * messages
1737 * @ctlr: the controller to check for queued messages
1738 *
1739 * If there are more messages in the queue, the next message is returned from
1740 * this call.
1741 *
1742 * Return: the next message in the queue, else NULL if the queue is empty.
1743 */
1744struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1745{
1746 struct spi_message *next;
1747 unsigned long flags;
1748
1749 /* get a pointer to the next message, if any */
1750 spin_lock_irqsave(&ctlr->queue_lock, flags);
1751 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1752 queue);
1753 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1754
1755 return next;
1756}
1757EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1758
1759/**
1760 * spi_finalize_current_message() - the current message is complete
1761 * @ctlr: the controller to return the message to
1762 *
1763 * Called by the driver to notify the core that the message in the front of the
1764 * queue is complete and can be removed from the queue.
1765 */
1766void spi_finalize_current_message(struct spi_controller *ctlr)
1767{
1768 struct spi_transfer *xfer;
1769 struct spi_message *mesg;
1770 unsigned long flags;
1771 int ret;
1772
1773 spin_lock_irqsave(&ctlr->queue_lock, flags);
1774 mesg = ctlr->cur_msg;
1775 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1776
1777 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1778 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1779 ptp_read_system_postts(xfer->ptp_sts);
1780 xfer->ptp_sts_word_post = xfer->len;
1781 }
1782 }
1783
1784 if (unlikely(ctlr->ptp_sts_supported))
1785 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1786 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1787
1788 spi_unmap_msg(ctlr, mesg);
1789
1790 /* In the prepare_messages callback the spi bus has the opportunity to
1791 * split a transfer to smaller chunks.
1792 * Release splited transfers here since spi_map_msg is done on the
1793 * splited transfers.
1794 */
1795 spi_res_release(ctlr, mesg);
1796
1797 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1798 ret = ctlr->unprepare_message(ctlr, mesg);
1799 if (ret) {
1800 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1801 ret);
1802 }
1803 }
1804
1805 spin_lock_irqsave(&ctlr->queue_lock, flags);
1806 ctlr->cur_msg = NULL;
1807 ctlr->cur_msg_prepared = false;
1808 ctlr->fallback = false;
1809 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1810 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1811
1812 trace_spi_message_done(mesg);
1813
1814 mesg->state = NULL;
1815 if (mesg->complete)
1816 mesg->complete(mesg->context);
1817}
1818EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1819
1820static int spi_start_queue(struct spi_controller *ctlr)
1821{
1822 unsigned long flags;
1823
1824 spin_lock_irqsave(&ctlr->queue_lock, flags);
1825
1826 if (ctlr->running || ctlr->busy) {
1827 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1828 return -EBUSY;
1829 }
1830
1831 ctlr->running = true;
1832 ctlr->cur_msg = NULL;
1833 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1834
1835 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1836
1837 return 0;
1838}
1839
1840static int spi_stop_queue(struct spi_controller *ctlr)
1841{
1842 unsigned long flags;
1843 unsigned limit = 500;
1844 int ret = 0;
1845
1846 spin_lock_irqsave(&ctlr->queue_lock, flags);
1847
1848 /*
1849 * This is a bit lame, but is optimized for the common execution path.
1850 * A wait_queue on the ctlr->busy could be used, but then the common
1851 * execution path (pump_messages) would be required to call wake_up or
1852 * friends on every SPI message. Do this instead.
1853 */
1854 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1855 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1856 usleep_range(10000, 11000);
1857 spin_lock_irqsave(&ctlr->queue_lock, flags);
1858 }
1859
1860 if (!list_empty(&ctlr->queue) || ctlr->busy)
1861 ret = -EBUSY;
1862 else
1863 ctlr->running = false;
1864
1865 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1866
1867 if (ret) {
1868 dev_warn(&ctlr->dev, "could not stop message queue\n");
1869 return ret;
1870 }
1871 return ret;
1872}
1873
1874static int spi_destroy_queue(struct spi_controller *ctlr)
1875{
1876 int ret;
1877
1878 ret = spi_stop_queue(ctlr);
1879
1880 /*
1881 * kthread_flush_worker will block until all work is done.
1882 * If the reason that stop_queue timed out is that the work will never
1883 * finish, then it does no good to call flush/stop thread, so
1884 * return anyway.
1885 */
1886 if (ret) {
1887 dev_err(&ctlr->dev, "problem destroying queue\n");
1888 return ret;
1889 }
1890
1891 kthread_destroy_worker(ctlr->kworker);
1892
1893 return 0;
1894}
1895
1896static int __spi_queued_transfer(struct spi_device *spi,
1897 struct spi_message *msg,
1898 bool need_pump)
1899{
1900 struct spi_controller *ctlr = spi->controller;
1901 unsigned long flags;
1902
1903 spin_lock_irqsave(&ctlr->queue_lock, flags);
1904
1905 if (!ctlr->running) {
1906 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1907 return -ESHUTDOWN;
1908 }
1909 msg->actual_length = 0;
1910 msg->status = -EINPROGRESS;
1911
1912 list_add_tail(&msg->queue, &ctlr->queue);
1913 if (!ctlr->busy && need_pump)
1914 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1915
1916 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1917 return 0;
1918}
1919
1920/**
1921 * spi_queued_transfer - transfer function for queued transfers
1922 * @spi: spi device which is requesting transfer
1923 * @msg: spi message which is to handled is queued to driver queue
1924 *
1925 * Return: zero on success, else a negative error code.
1926 */
1927static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1928{
1929 return __spi_queued_transfer(spi, msg, true);
1930}
1931
1932static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1933{
1934 int ret;
1935
1936 ctlr->transfer = spi_queued_transfer;
1937 if (!ctlr->transfer_one_message)
1938 ctlr->transfer_one_message = spi_transfer_one_message;
1939
1940 /* Initialize and start queue */
1941 ret = spi_init_queue(ctlr);
1942 if (ret) {
1943 dev_err(&ctlr->dev, "problem initializing queue\n");
1944 goto err_init_queue;
1945 }
1946 ctlr->queued = true;
1947 ret = spi_start_queue(ctlr);
1948 if (ret) {
1949 dev_err(&ctlr->dev, "problem starting queue\n");
1950 goto err_start_queue;
1951 }
1952
1953 return 0;
1954
1955err_start_queue:
1956 spi_destroy_queue(ctlr);
1957err_init_queue:
1958 return ret;
1959}
1960
1961/**
1962 * spi_flush_queue - Send all pending messages in the queue from the callers'
1963 * context
1964 * @ctlr: controller to process queue for
1965 *
1966 * This should be used when one wants to ensure all pending messages have been
1967 * sent before doing something. Is used by the spi-mem code to make sure SPI
1968 * memory operations do not preempt regular SPI transfers that have been queued
1969 * before the spi-mem operation.
1970 */
1971void spi_flush_queue(struct spi_controller *ctlr)
1972{
1973 if (ctlr->transfer == spi_queued_transfer)
1974 __spi_pump_messages(ctlr, false);
1975}
1976
1977/*-------------------------------------------------------------------------*/
1978
1979#if defined(CONFIG_OF)
1980static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1981 struct device_node *nc)
1982{
1983 u32 value;
1984 int rc;
1985
1986 /* Mode (clock phase/polarity/etc.) */
1987 if (of_property_read_bool(nc, "spi-cpha"))
1988 spi->mode |= SPI_CPHA;
1989 if (of_property_read_bool(nc, "spi-cpol"))
1990 spi->mode |= SPI_CPOL;
1991 if (of_property_read_bool(nc, "spi-3wire"))
1992 spi->mode |= SPI_3WIRE;
1993 if (of_property_read_bool(nc, "spi-lsb-first"))
1994 spi->mode |= SPI_LSB_FIRST;
1995 if (of_property_read_bool(nc, "spi-cs-high"))
1996 spi->mode |= SPI_CS_HIGH;
1997
1998 /* Device DUAL/QUAD mode */
1999 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
2000 switch (value) {
2001 case 0:
2002 spi->mode |= SPI_NO_TX;
2003 break;
2004 case 1:
2005 break;
2006 case 2:
2007 spi->mode |= SPI_TX_DUAL;
2008 break;
2009 case 4:
2010 spi->mode |= SPI_TX_QUAD;
2011 break;
2012 case 8:
2013 spi->mode |= SPI_TX_OCTAL;
2014 break;
2015 default:
2016 dev_warn(&ctlr->dev,
2017 "spi-tx-bus-width %d not supported\n",
2018 value);
2019 break;
2020 }
2021 }
2022
2023 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
2024 switch (value) {
2025 case 0:
2026 spi->mode |= SPI_NO_RX;
2027 break;
2028 case 1:
2029 break;
2030 case 2:
2031 spi->mode |= SPI_RX_DUAL;
2032 break;
2033 case 4:
2034 spi->mode |= SPI_RX_QUAD;
2035 break;
2036 case 8:
2037 spi->mode |= SPI_RX_OCTAL;
2038 break;
2039 default:
2040 dev_warn(&ctlr->dev,
2041 "spi-rx-bus-width %d not supported\n",
2042 value);
2043 break;
2044 }
2045 }
2046
2047 if (spi_controller_is_slave(ctlr)) {
2048 if (!of_node_name_eq(nc, "slave")) {
2049 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
2050 nc);
2051 return -EINVAL;
2052 }
2053 return 0;
2054 }
2055
2056 /* Device address */
2057 rc = of_property_read_u32(nc, "reg", &value);
2058 if (rc) {
2059 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
2060 nc, rc);
2061 return rc;
2062 }
2063 spi->chip_select = value;
2064
2065 /* Device speed */
2066 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2067 spi->max_speed_hz = value;
2068
2069 return 0;
2070}
2071
2072static struct spi_device *
2073of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2074{
2075 struct spi_device *spi;
2076 int rc;
2077
2078 /* Alloc an spi_device */
2079 spi = spi_alloc_device(ctlr);
2080 if (!spi) {
2081 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2082 rc = -ENOMEM;
2083 goto err_out;
2084 }
2085
2086 /* Select device driver */
2087 rc = of_modalias_node(nc, spi->modalias,
2088 sizeof(spi->modalias));
2089 if (rc < 0) {
2090 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2091 goto err_out;
2092 }
2093
2094 rc = of_spi_parse_dt(ctlr, spi, nc);
2095 if (rc)
2096 goto err_out;
2097
2098 /* Store a pointer to the node in the device structure */
2099 of_node_get(nc);
2100 spi->dev.of_node = nc;
2101 spi->dev.fwnode = of_fwnode_handle(nc);
2102
2103 /* Register the new device */
2104 rc = spi_add_device(spi);
2105 if (rc) {
2106 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2107 goto err_of_node_put;
2108 }
2109
2110 return spi;
2111
2112err_of_node_put:
2113 of_node_put(nc);
2114err_out:
2115 spi_dev_put(spi);
2116 return ERR_PTR(rc);
2117}
2118
2119/**
2120 * of_register_spi_devices() - Register child devices onto the SPI bus
2121 * @ctlr: Pointer to spi_controller device
2122 *
2123 * Registers an spi_device for each child node of controller node which
2124 * represents a valid SPI slave.
2125 */
2126static void of_register_spi_devices(struct spi_controller *ctlr)
2127{
2128 struct spi_device *spi;
2129 struct device_node *nc;
2130
2131 if (!ctlr->dev.of_node)
2132 return;
2133
2134 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2135 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2136 continue;
2137 spi = of_register_spi_device(ctlr, nc);
2138 if (IS_ERR(spi)) {
2139 dev_warn(&ctlr->dev,
2140 "Failed to create SPI device for %pOF\n", nc);
2141 of_node_clear_flag(nc, OF_POPULATED);
2142 }
2143 }
2144}
2145#else
2146static void of_register_spi_devices(struct spi_controller *ctlr) { }
2147#endif
2148
2149/**
2150 * spi_new_ancillary_device() - Register ancillary SPI device
2151 * @spi: Pointer to the main SPI device registering the ancillary device
2152 * @chip_select: Chip Select of the ancillary device
2153 *
2154 * Register an ancillary SPI device; for example some chips have a chip-select
2155 * for normal device usage and another one for setup/firmware upload.
2156 *
2157 * This may only be called from main SPI device's probe routine.
2158 *
2159 * Return: 0 on success; negative errno on failure
2160 */
2161struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
2162 u8 chip_select)
2163{
2164 struct spi_device *ancillary;
2165 int rc = 0;
2166
2167 /* Alloc an spi_device */
2168 ancillary = spi_alloc_device(spi->controller);
2169 if (!ancillary) {
2170 rc = -ENOMEM;
2171 goto err_out;
2172 }
2173
2174 strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
2175
2176 /* Use provided chip-select for ancillary device */
2177 ancillary->chip_select = chip_select;
2178
2179 /* Take over SPI mode/speed from SPI main device */
2180 ancillary->max_speed_hz = spi->max_speed_hz;
2181 ancillary->mode = spi->mode;
2182
2183 /* Register the new device */
2184 rc = spi_add_device_locked(ancillary);
2185 if (rc) {
2186 dev_err(&spi->dev, "failed to register ancillary device\n");
2187 goto err_out;
2188 }
2189
2190 return ancillary;
2191
2192err_out:
2193 spi_dev_put(ancillary);
2194 return ERR_PTR(rc);
2195}
2196EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
2197
2198#ifdef CONFIG_ACPI
2199struct acpi_spi_lookup {
2200 struct spi_controller *ctlr;
2201 u32 max_speed_hz;
2202 u32 mode;
2203 int irq;
2204 u8 bits_per_word;
2205 u8 chip_select;
2206};
2207
2208static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2209 struct acpi_spi_lookup *lookup)
2210{
2211 const union acpi_object *obj;
2212
2213 if (!x86_apple_machine)
2214 return;
2215
2216 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2217 && obj->buffer.length >= 4)
2218 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2219
2220 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2221 && obj->buffer.length == 8)
2222 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2223
2224 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2225 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2226 lookup->mode |= SPI_LSB_FIRST;
2227
2228 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2229 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2230 lookup->mode |= SPI_CPOL;
2231
2232 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2233 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2234 lookup->mode |= SPI_CPHA;
2235}
2236
2237static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2238{
2239 struct acpi_spi_lookup *lookup = data;
2240 struct spi_controller *ctlr = lookup->ctlr;
2241
2242 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2243 struct acpi_resource_spi_serialbus *sb;
2244 acpi_handle parent_handle;
2245 acpi_status status;
2246
2247 sb = &ares->data.spi_serial_bus;
2248 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2249
2250 status = acpi_get_handle(NULL,
2251 sb->resource_source.string_ptr,
2252 &parent_handle);
2253
2254 if (ACPI_FAILURE(status) ||
2255 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2256 return -ENODEV;
2257
2258 /*
2259 * ACPI DeviceSelection numbering is handled by the
2260 * host controller driver in Windows and can vary
2261 * from driver to driver. In Linux we always expect
2262 * 0 .. max - 1 so we need to ask the driver to
2263 * translate between the two schemes.
2264 */
2265 if (ctlr->fw_translate_cs) {
2266 int cs = ctlr->fw_translate_cs(ctlr,
2267 sb->device_selection);
2268 if (cs < 0)
2269 return cs;
2270 lookup->chip_select = cs;
2271 } else {
2272 lookup->chip_select = sb->device_selection;
2273 }
2274
2275 lookup->max_speed_hz = sb->connection_speed;
2276 lookup->bits_per_word = sb->data_bit_length;
2277
2278 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2279 lookup->mode |= SPI_CPHA;
2280 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2281 lookup->mode |= SPI_CPOL;
2282 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2283 lookup->mode |= SPI_CS_HIGH;
2284 }
2285 } else if (lookup->irq < 0) {
2286 struct resource r;
2287
2288 if (acpi_dev_resource_interrupt(ares, 0, &r))
2289 lookup->irq = r.start;
2290 }
2291
2292 /* Always tell the ACPI core to skip this resource */
2293 return 1;
2294}
2295
2296static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2297 struct acpi_device *adev)
2298{
2299 acpi_handle parent_handle = NULL;
2300 struct list_head resource_list;
2301 struct acpi_spi_lookup lookup = {};
2302 struct spi_device *spi;
2303 int ret;
2304
2305 if (acpi_bus_get_status(adev) || !adev->status.present ||
2306 acpi_device_enumerated(adev))
2307 return AE_OK;
2308
2309 lookup.ctlr = ctlr;
2310 lookup.irq = -1;
2311
2312 INIT_LIST_HEAD(&resource_list);
2313 ret = acpi_dev_get_resources(adev, &resource_list,
2314 acpi_spi_add_resource, &lookup);
2315 acpi_dev_free_resource_list(&resource_list);
2316
2317 if (ret < 0)
2318 /* found SPI in _CRS but it points to another controller */
2319 return AE_OK;
2320
2321 if (!lookup.max_speed_hz &&
2322 ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&
2323 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2324 /* Apple does not use _CRS but nested devices for SPI slaves */
2325 acpi_spi_parse_apple_properties(adev, &lookup);
2326 }
2327
2328 if (!lookup.max_speed_hz)
2329 return AE_OK;
2330
2331 spi = spi_alloc_device(ctlr);
2332 if (!spi) {
2333 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2334 dev_name(&adev->dev));
2335 return AE_NO_MEMORY;
2336 }
2337
2338
2339 ACPI_COMPANION_SET(&spi->dev, adev);
2340 spi->max_speed_hz = lookup.max_speed_hz;
2341 spi->mode |= lookup.mode;
2342 spi->irq = lookup.irq;
2343 spi->bits_per_word = lookup.bits_per_word;
2344 spi->chip_select = lookup.chip_select;
2345
2346 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2347 sizeof(spi->modalias));
2348
2349 if (spi->irq < 0)
2350 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2351
2352 acpi_device_set_enumerated(adev);
2353
2354 adev->power.flags.ignore_parent = true;
2355 if (spi_add_device(spi)) {
2356 adev->power.flags.ignore_parent = false;
2357 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2358 dev_name(&adev->dev));
2359 spi_dev_put(spi);
2360 }
2361
2362 return AE_OK;
2363}
2364
2365static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2366 void *data, void **return_value)
2367{
2368 struct spi_controller *ctlr = data;
2369 struct acpi_device *adev;
2370
2371 if (acpi_bus_get_device(handle, &adev))
2372 return AE_OK;
2373
2374 return acpi_register_spi_device(ctlr, adev);
2375}
2376
2377#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2378
2379static void acpi_register_spi_devices(struct spi_controller *ctlr)
2380{
2381 acpi_status status;
2382 acpi_handle handle;
2383
2384 handle = ACPI_HANDLE(ctlr->dev.parent);
2385 if (!handle)
2386 return;
2387
2388 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2389 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2390 acpi_spi_add_device, NULL, ctlr, NULL);
2391 if (ACPI_FAILURE(status))
2392 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2393}
2394#else
2395static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2396#endif /* CONFIG_ACPI */
2397
2398static void spi_controller_release(struct device *dev)
2399{
2400 struct spi_controller *ctlr;
2401
2402 ctlr = container_of(dev, struct spi_controller, dev);
2403 kfree(ctlr);
2404}
2405
2406static struct class spi_master_class = {
2407 .name = "spi_master",
2408 .owner = THIS_MODULE,
2409 .dev_release = spi_controller_release,
2410 .dev_groups = spi_master_groups,
2411};
2412
2413#ifdef CONFIG_SPI_SLAVE
2414/**
2415 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2416 * controller
2417 * @spi: device used for the current transfer
2418 */
2419int spi_slave_abort(struct spi_device *spi)
2420{
2421 struct spi_controller *ctlr = spi->controller;
2422
2423 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2424 return ctlr->slave_abort(ctlr);
2425
2426 return -ENOTSUPP;
2427}
2428EXPORT_SYMBOL_GPL(spi_slave_abort);
2429
2430static int match_true(struct device *dev, void *data)
2431{
2432 return 1;
2433}
2434
2435static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2436 char *buf)
2437{
2438 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2439 dev);
2440 struct device *child;
2441
2442 child = device_find_child(&ctlr->dev, NULL, match_true);
2443 return sprintf(buf, "%s\n",
2444 child ? to_spi_device(child)->modalias : NULL);
2445}
2446
2447static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2448 const char *buf, size_t count)
2449{
2450 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2451 dev);
2452 struct spi_device *spi;
2453 struct device *child;
2454 char name[32];
2455 int rc;
2456
2457 rc = sscanf(buf, "%31s", name);
2458 if (rc != 1 || !name[0])
2459 return -EINVAL;
2460
2461 child = device_find_child(&ctlr->dev, NULL, match_true);
2462 if (child) {
2463 /* Remove registered slave */
2464 device_unregister(child);
2465 put_device(child);
2466 }
2467
2468 if (strcmp(name, "(null)")) {
2469 /* Register new slave */
2470 spi = spi_alloc_device(ctlr);
2471 if (!spi)
2472 return -ENOMEM;
2473
2474 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2475
2476 rc = spi_add_device(spi);
2477 if (rc) {
2478 spi_dev_put(spi);
2479 return rc;
2480 }
2481 }
2482
2483 return count;
2484}
2485
2486static DEVICE_ATTR_RW(slave);
2487
2488static struct attribute *spi_slave_attrs[] = {
2489 &dev_attr_slave.attr,
2490 NULL,
2491};
2492
2493static const struct attribute_group spi_slave_group = {
2494 .attrs = spi_slave_attrs,
2495};
2496
2497static const struct attribute_group *spi_slave_groups[] = {
2498 &spi_controller_statistics_group,
2499 &spi_slave_group,
2500 NULL,
2501};
2502
2503static struct class spi_slave_class = {
2504 .name = "spi_slave",
2505 .owner = THIS_MODULE,
2506 .dev_release = spi_controller_release,
2507 .dev_groups = spi_slave_groups,
2508};
2509#else
2510extern struct class spi_slave_class; /* dummy */
2511#endif
2512
2513/**
2514 * __spi_alloc_controller - allocate an SPI master or slave controller
2515 * @dev: the controller, possibly using the platform_bus
2516 * @size: how much zeroed driver-private data to allocate; the pointer to this
2517 * memory is in the driver_data field of the returned device, accessible
2518 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2519 * drivers granting DMA access to portions of their private data need to
2520 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2521 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2522 * slave (true) controller
2523 * Context: can sleep
2524 *
2525 * This call is used only by SPI controller drivers, which are the
2526 * only ones directly touching chip registers. It's how they allocate
2527 * an spi_controller structure, prior to calling spi_register_controller().
2528 *
2529 * This must be called from context that can sleep.
2530 *
2531 * The caller is responsible for assigning the bus number and initializing the
2532 * controller's methods before calling spi_register_controller(); and (after
2533 * errors adding the device) calling spi_controller_put() to prevent a memory
2534 * leak.
2535 *
2536 * Return: the SPI controller structure on success, else NULL.
2537 */
2538struct spi_controller *__spi_alloc_controller(struct device *dev,
2539 unsigned int size, bool slave)
2540{
2541 struct spi_controller *ctlr;
2542 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2543
2544 if (!dev)
2545 return NULL;
2546
2547 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2548 if (!ctlr)
2549 return NULL;
2550
2551 device_initialize(&ctlr->dev);
2552 INIT_LIST_HEAD(&ctlr->queue);
2553 spin_lock_init(&ctlr->queue_lock);
2554 spin_lock_init(&ctlr->bus_lock_spinlock);
2555 mutex_init(&ctlr->bus_lock_mutex);
2556 mutex_init(&ctlr->io_mutex);
2557 mutex_init(&ctlr->add_lock);
2558 ctlr->bus_num = -1;
2559 ctlr->num_chipselect = 1;
2560 ctlr->slave = slave;
2561 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2562 ctlr->dev.class = &spi_slave_class;
2563 else
2564 ctlr->dev.class = &spi_master_class;
2565 ctlr->dev.parent = dev;
2566 pm_suspend_ignore_children(&ctlr->dev, true);
2567 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2568
2569 return ctlr;
2570}
2571EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2572
2573static void devm_spi_release_controller(struct device *dev, void *ctlr)
2574{
2575 spi_controller_put(*(struct spi_controller **)ctlr);
2576}
2577
2578/**
2579 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()
2580 * @dev: physical device of SPI controller
2581 * @size: how much zeroed driver-private data to allocate
2582 * @slave: whether to allocate an SPI master (false) or SPI slave (true)
2583 * Context: can sleep
2584 *
2585 * Allocate an SPI controller and automatically release a reference on it
2586 * when @dev is unbound from its driver. Drivers are thus relieved from
2587 * having to call spi_controller_put().
2588 *
2589 * The arguments to this function are identical to __spi_alloc_controller().
2590 *
2591 * Return: the SPI controller structure on success, else NULL.
2592 */
2593struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
2594 unsigned int size,
2595 bool slave)
2596{
2597 struct spi_controller **ptr, *ctlr;
2598
2599 ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),
2600 GFP_KERNEL);
2601 if (!ptr)
2602 return NULL;
2603
2604 ctlr = __spi_alloc_controller(dev, size, slave);
2605 if (ctlr) {
2606 ctlr->devm_allocated = true;
2607 *ptr = ctlr;
2608 devres_add(dev, ptr);
2609 } else {
2610 devres_free(ptr);
2611 }
2612
2613 return ctlr;
2614}
2615EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);
2616
2617#ifdef CONFIG_OF
2618static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2619{
2620 int nb, i, *cs;
2621 struct device_node *np = ctlr->dev.of_node;
2622
2623 if (!np)
2624 return 0;
2625
2626 nb = of_gpio_named_count(np, "cs-gpios");
2627 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2628
2629 /* Return error only for an incorrectly formed cs-gpios property */
2630 if (nb == 0 || nb == -ENOENT)
2631 return 0;
2632 else if (nb < 0)
2633 return nb;
2634
2635 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2636 GFP_KERNEL);
2637 ctlr->cs_gpios = cs;
2638
2639 if (!ctlr->cs_gpios)
2640 return -ENOMEM;
2641
2642 for (i = 0; i < ctlr->num_chipselect; i++)
2643 cs[i] = -ENOENT;
2644
2645 for (i = 0; i < nb; i++)
2646 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2647
2648 return 0;
2649}
2650#else
2651static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2652{
2653 return 0;
2654}
2655#endif
2656
2657/**
2658 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2659 * @ctlr: The SPI master to grab GPIO descriptors for
2660 */
2661static int spi_get_gpio_descs(struct spi_controller *ctlr)
2662{
2663 int nb, i;
2664 struct gpio_desc **cs;
2665 struct device *dev = &ctlr->dev;
2666 unsigned long native_cs_mask = 0;
2667 unsigned int num_cs_gpios = 0;
2668
2669 nb = gpiod_count(dev, "cs");
2670 if (nb < 0) {
2671 /* No GPIOs at all is fine, else return the error */
2672 if (nb == -ENOENT)
2673 return 0;
2674 return nb;
2675 }
2676
2677 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2678
2679 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2680 GFP_KERNEL);
2681 if (!cs)
2682 return -ENOMEM;
2683 ctlr->cs_gpiods = cs;
2684
2685 for (i = 0; i < nb; i++) {
2686 /*
2687 * Most chipselects are active low, the inverted
2688 * semantics are handled by special quirks in gpiolib,
2689 * so initializing them GPIOD_OUT_LOW here means
2690 * "unasserted", in most cases this will drive the physical
2691 * line high.
2692 */
2693 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2694 GPIOD_OUT_LOW);
2695 if (IS_ERR(cs[i]))
2696 return PTR_ERR(cs[i]);
2697
2698 if (cs[i]) {
2699 /*
2700 * If we find a CS GPIO, name it after the device and
2701 * chip select line.
2702 */
2703 char *gpioname;
2704
2705 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2706 dev_name(dev), i);
2707 if (!gpioname)
2708 return -ENOMEM;
2709 gpiod_set_consumer_name(cs[i], gpioname);
2710 num_cs_gpios++;
2711 continue;
2712 }
2713
2714 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2715 dev_err(dev, "Invalid native chip select %d\n", i);
2716 return -EINVAL;
2717 }
2718 native_cs_mask |= BIT(i);
2719 }
2720
2721 ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;
2722
2723 if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios &&
2724 ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
2725 dev_err(dev, "No unused native chip select available\n");
2726 return -EINVAL;
2727 }
2728
2729 return 0;
2730}
2731
2732static int spi_controller_check_ops(struct spi_controller *ctlr)
2733{
2734 /*
2735 * The controller may implement only the high-level SPI-memory like
2736 * operations if it does not support regular SPI transfers, and this is
2737 * valid use case.
2738 * If ->mem_ops is NULL, we request that at least one of the
2739 * ->transfer_xxx() method be implemented.
2740 */
2741 if (ctlr->mem_ops) {
2742 if (!ctlr->mem_ops->exec_op)
2743 return -EINVAL;
2744 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2745 !ctlr->transfer_one_message) {
2746 return -EINVAL;
2747 }
2748
2749 return 0;
2750}
2751
2752/**
2753 * spi_register_controller - register SPI master or slave controller
2754 * @ctlr: initialized master, originally from spi_alloc_master() or
2755 * spi_alloc_slave()
2756 * Context: can sleep
2757 *
2758 * SPI controllers connect to their drivers using some non-SPI bus,
2759 * such as the platform bus. The final stage of probe() in that code
2760 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2761 *
2762 * SPI controllers use board specific (often SOC specific) bus numbers,
2763 * and board-specific addressing for SPI devices combines those numbers
2764 * with chip select numbers. Since SPI does not directly support dynamic
2765 * device identification, boards need configuration tables telling which
2766 * chip is at which address.
2767 *
2768 * This must be called from context that can sleep. It returns zero on
2769 * success, else a negative error code (dropping the controller's refcount).
2770 * After a successful return, the caller is responsible for calling
2771 * spi_unregister_controller().
2772 *
2773 * Return: zero on success, else a negative error code.
2774 */
2775int spi_register_controller(struct spi_controller *ctlr)
2776{
2777 struct device *dev = ctlr->dev.parent;
2778 struct boardinfo *bi;
2779 int status;
2780 int id, first_dynamic;
2781
2782 if (!dev)
2783 return -ENODEV;
2784
2785 /*
2786 * Make sure all necessary hooks are implemented before registering
2787 * the SPI controller.
2788 */
2789 status = spi_controller_check_ops(ctlr);
2790 if (status)
2791 return status;
2792
2793 if (ctlr->bus_num >= 0) {
2794 /* devices with a fixed bus num must check-in with the num */
2795 mutex_lock(&board_lock);
2796 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2797 ctlr->bus_num + 1, GFP_KERNEL);
2798 mutex_unlock(&board_lock);
2799 if (WARN(id < 0, "couldn't get idr"))
2800 return id == -ENOSPC ? -EBUSY : id;
2801 ctlr->bus_num = id;
2802 } else if (ctlr->dev.of_node) {
2803 /* allocate dynamic bus number using Linux idr */
2804 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2805 if (id >= 0) {
2806 ctlr->bus_num = id;
2807 mutex_lock(&board_lock);
2808 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2809 ctlr->bus_num + 1, GFP_KERNEL);
2810 mutex_unlock(&board_lock);
2811 if (WARN(id < 0, "couldn't get idr"))
2812 return id == -ENOSPC ? -EBUSY : id;
2813 }
2814 }
2815 if (ctlr->bus_num < 0) {
2816 first_dynamic = of_alias_get_highest_id("spi");
2817 if (first_dynamic < 0)
2818 first_dynamic = 0;
2819 else
2820 first_dynamic++;
2821
2822 mutex_lock(&board_lock);
2823 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2824 0, GFP_KERNEL);
2825 mutex_unlock(&board_lock);
2826 if (WARN(id < 0, "couldn't get idr"))
2827 return id;
2828 ctlr->bus_num = id;
2829 }
2830 ctlr->bus_lock_flag = 0;
2831 init_completion(&ctlr->xfer_completion);
2832 if (!ctlr->max_dma_len)
2833 ctlr->max_dma_len = INT_MAX;
2834
2835 /* register the device, then userspace will see it.
2836 * registration fails if the bus ID is in use.
2837 */
2838 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2839
2840 if (!spi_controller_is_slave(ctlr)) {
2841 if (ctlr->use_gpio_descriptors) {
2842 status = spi_get_gpio_descs(ctlr);
2843 if (status)
2844 goto free_bus_id;
2845 /*
2846 * A controller using GPIO descriptors always
2847 * supports SPI_CS_HIGH if need be.
2848 */
2849 ctlr->mode_bits |= SPI_CS_HIGH;
2850 } else {
2851 /* Legacy code path for GPIOs from DT */
2852 status = of_spi_get_gpio_numbers(ctlr);
2853 if (status)
2854 goto free_bus_id;
2855 }
2856 }
2857
2858 /*
2859 * Even if it's just one always-selected device, there must
2860 * be at least one chipselect.
2861 */
2862 if (!ctlr->num_chipselect) {
2863 status = -EINVAL;
2864 goto free_bus_id;
2865 }
2866
2867 status = device_add(&ctlr->dev);
2868 if (status < 0)
2869 goto free_bus_id;
2870 dev_dbg(dev, "registered %s %s\n",
2871 spi_controller_is_slave(ctlr) ? "slave" : "master",
2872 dev_name(&ctlr->dev));
2873
2874 /*
2875 * If we're using a queued driver, start the queue. Note that we don't
2876 * need the queueing logic if the driver is only supporting high-level
2877 * memory operations.
2878 */
2879 if (ctlr->transfer) {
2880 dev_info(dev, "controller is unqueued, this is deprecated\n");
2881 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2882 status = spi_controller_initialize_queue(ctlr);
2883 if (status) {
2884 device_del(&ctlr->dev);
2885 goto free_bus_id;
2886 }
2887 }
2888 /* add statistics */
2889 spin_lock_init(&ctlr->statistics.lock);
2890
2891 mutex_lock(&board_lock);
2892 list_add_tail(&ctlr->list, &spi_controller_list);
2893 list_for_each_entry(bi, &board_list, list)
2894 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2895 mutex_unlock(&board_lock);
2896
2897 /* Register devices from the device tree and ACPI */
2898 of_register_spi_devices(ctlr);
2899 acpi_register_spi_devices(ctlr);
2900 return status;
2901
2902free_bus_id:
2903 mutex_lock(&board_lock);
2904 idr_remove(&spi_master_idr, ctlr->bus_num);
2905 mutex_unlock(&board_lock);
2906 return status;
2907}
2908EXPORT_SYMBOL_GPL(spi_register_controller);
2909
2910static void devm_spi_unregister(void *ctlr)
2911{
2912 spi_unregister_controller(ctlr);
2913}
2914
2915/**
2916 * devm_spi_register_controller - register managed SPI master or slave
2917 * controller
2918 * @dev: device managing SPI controller
2919 * @ctlr: initialized controller, originally from spi_alloc_master() or
2920 * spi_alloc_slave()
2921 * Context: can sleep
2922 *
2923 * Register a SPI device as with spi_register_controller() which will
2924 * automatically be unregistered and freed.
2925 *
2926 * Return: zero on success, else a negative error code.
2927 */
2928int devm_spi_register_controller(struct device *dev,
2929 struct spi_controller *ctlr)
2930{
2931 int ret;
2932
2933 ret = spi_register_controller(ctlr);
2934 if (ret)
2935 return ret;
2936
2937 return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
2938}
2939EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2940
2941static int __unregister(struct device *dev, void *null)
2942{
2943 spi_unregister_device(to_spi_device(dev));
2944 return 0;
2945}
2946
2947/**
2948 * spi_unregister_controller - unregister SPI master or slave controller
2949 * @ctlr: the controller being unregistered
2950 * Context: can sleep
2951 *
2952 * This call is used only by SPI controller drivers, which are the
2953 * only ones directly touching chip registers.
2954 *
2955 * This must be called from context that can sleep.
2956 *
2957 * Note that this function also drops a reference to the controller.
2958 */
2959void spi_unregister_controller(struct spi_controller *ctlr)
2960{
2961 struct spi_controller *found;
2962 int id = ctlr->bus_num;
2963
2964 /* Prevent addition of new devices, unregister existing ones */
2965 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2966 mutex_lock(&ctlr->add_lock);
2967
2968 device_for_each_child(&ctlr->dev, NULL, __unregister);
2969
2970 /* First make sure that this controller was ever added */
2971 mutex_lock(&board_lock);
2972 found = idr_find(&spi_master_idr, id);
2973 mutex_unlock(&board_lock);
2974 if (ctlr->queued) {
2975 if (spi_destroy_queue(ctlr))
2976 dev_err(&ctlr->dev, "queue remove failed\n");
2977 }
2978 mutex_lock(&board_lock);
2979 list_del(&ctlr->list);
2980 mutex_unlock(&board_lock);
2981
2982 device_del(&ctlr->dev);
2983
2984 /* Release the last reference on the controller if its driver
2985 * has not yet been converted to devm_spi_alloc_master/slave().
2986 */
2987 if (!ctlr->devm_allocated)
2988 put_device(&ctlr->dev);
2989
2990 /* free bus id */
2991 mutex_lock(&board_lock);
2992 if (found == ctlr)
2993 idr_remove(&spi_master_idr, id);
2994 mutex_unlock(&board_lock);
2995
2996 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2997 mutex_unlock(&ctlr->add_lock);
2998}
2999EXPORT_SYMBOL_GPL(spi_unregister_controller);
3000
3001int spi_controller_suspend(struct spi_controller *ctlr)
3002{
3003 int ret;
3004
3005 /* Basically no-ops for non-queued controllers */
3006 if (!ctlr->queued)
3007 return 0;
3008
3009 ret = spi_stop_queue(ctlr);
3010 if (ret)
3011 dev_err(&ctlr->dev, "queue stop failed\n");
3012
3013 return ret;
3014}
3015EXPORT_SYMBOL_GPL(spi_controller_suspend);
3016
3017int spi_controller_resume(struct spi_controller *ctlr)
3018{
3019 int ret;
3020
3021 if (!ctlr->queued)
3022 return 0;
3023
3024 ret = spi_start_queue(ctlr);
3025 if (ret)
3026 dev_err(&ctlr->dev, "queue restart failed\n");
3027
3028 return ret;
3029}
3030EXPORT_SYMBOL_GPL(spi_controller_resume);
3031
3032static int __spi_controller_match(struct device *dev, const void *data)
3033{
3034 struct spi_controller *ctlr;
3035 const u16 *bus_num = data;
3036
3037 ctlr = container_of(dev, struct spi_controller, dev);
3038 return ctlr->bus_num == *bus_num;
3039}
3040
3041/**
3042 * spi_busnum_to_master - look up master associated with bus_num
3043 * @bus_num: the master's bus number
3044 * Context: can sleep
3045 *
3046 * This call may be used with devices that are registered after
3047 * arch init time. It returns a refcounted pointer to the relevant
3048 * spi_controller (which the caller must release), or NULL if there is
3049 * no such master registered.
3050 *
3051 * Return: the SPI master structure on success, else NULL.
3052 */
3053struct spi_controller *spi_busnum_to_master(u16 bus_num)
3054{
3055 struct device *dev;
3056 struct spi_controller *ctlr = NULL;
3057
3058 dev = class_find_device(&spi_master_class, NULL, &bus_num,
3059 __spi_controller_match);
3060 if (dev)
3061 ctlr = container_of(dev, struct spi_controller, dev);
3062 /* reference got in class_find_device */
3063 return ctlr;
3064}
3065EXPORT_SYMBOL_GPL(spi_busnum_to_master);
3066
3067/*-------------------------------------------------------------------------*/
3068
3069/* Core methods for SPI resource management */
3070
3071/**
3072 * spi_res_alloc - allocate a spi resource that is life-cycle managed
3073 * during the processing of a spi_message while using
3074 * spi_transfer_one
3075 * @spi: the spi device for which we allocate memory
3076 * @release: the release code to execute for this resource
3077 * @size: size to alloc and return
3078 * @gfp: GFP allocation flags
3079 *
3080 * Return: the pointer to the allocated data
3081 *
3082 * This may get enhanced in the future to allocate from a memory pool
3083 * of the @spi_device or @spi_controller to avoid repeated allocations.
3084 */
3085void *spi_res_alloc(struct spi_device *spi,
3086 spi_res_release_t release,
3087 size_t size, gfp_t gfp)
3088{
3089 struct spi_res *sres;
3090
3091 sres = kzalloc(sizeof(*sres) + size, gfp);
3092 if (!sres)
3093 return NULL;
3094
3095 INIT_LIST_HEAD(&sres->entry);
3096 sres->release = release;
3097
3098 return sres->data;
3099}
3100EXPORT_SYMBOL_GPL(spi_res_alloc);
3101
3102/**
3103 * spi_res_free - free an spi resource
3104 * @res: pointer to the custom data of a resource
3105 *
3106 */
3107void spi_res_free(void *res)
3108{
3109 struct spi_res *sres = container_of(res, struct spi_res, data);
3110
3111 if (!res)
3112 return;
3113
3114 WARN_ON(!list_empty(&sres->entry));
3115 kfree(sres);
3116}
3117EXPORT_SYMBOL_GPL(spi_res_free);
3118
3119/**
3120 * spi_res_add - add a spi_res to the spi_message
3121 * @message: the spi message
3122 * @res: the spi_resource
3123 */
3124void spi_res_add(struct spi_message *message, void *res)
3125{
3126 struct spi_res *sres = container_of(res, struct spi_res, data);
3127
3128 WARN_ON(!list_empty(&sres->entry));
3129 list_add_tail(&sres->entry, &message->resources);
3130}
3131EXPORT_SYMBOL_GPL(spi_res_add);
3132
3133/**
3134 * spi_res_release - release all spi resources for this message
3135 * @ctlr: the @spi_controller
3136 * @message: the @spi_message
3137 */
3138void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
3139{
3140 struct spi_res *res, *tmp;
3141
3142 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
3143 if (res->release)
3144 res->release(ctlr, message, res->data);
3145
3146 list_del(&res->entry);
3147
3148 kfree(res);
3149 }
3150}
3151EXPORT_SYMBOL_GPL(spi_res_release);
3152
3153/*-------------------------------------------------------------------------*/
3154
3155/* Core methods for spi_message alterations */
3156
3157static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3158 struct spi_message *msg,
3159 void *res)
3160{
3161 struct spi_replaced_transfers *rxfer = res;
3162 size_t i;
3163
3164 /* call extra callback if requested */
3165 if (rxfer->release)
3166 rxfer->release(ctlr, msg, res);
3167
3168 /* insert replaced transfers back into the message */
3169 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3170
3171 /* remove the formerly inserted entries */
3172 for (i = 0; i < rxfer->inserted; i++)
3173 list_del(&rxfer->inserted_transfers[i].transfer_list);
3174}
3175
3176/**
3177 * spi_replace_transfers - replace transfers with several transfers
3178 * and register change with spi_message.resources
3179 * @msg: the spi_message we work upon
3180 * @xfer_first: the first spi_transfer we want to replace
3181 * @remove: number of transfers to remove
3182 * @insert: the number of transfers we want to insert instead
3183 * @release: extra release code necessary in some circumstances
3184 * @extradatasize: extra data to allocate (with alignment guarantees
3185 * of struct @spi_transfer)
3186 * @gfp: gfp flags
3187 *
3188 * Returns: pointer to @spi_replaced_transfers,
3189 * PTR_ERR(...) in case of errors.
3190 */
3191struct spi_replaced_transfers *spi_replace_transfers(
3192 struct spi_message *msg,
3193 struct spi_transfer *xfer_first,
3194 size_t remove,
3195 size_t insert,
3196 spi_replaced_release_t release,
3197 size_t extradatasize,
3198 gfp_t gfp)
3199{
3200 struct spi_replaced_transfers *rxfer;
3201 struct spi_transfer *xfer;
3202 size_t i;
3203
3204 /* allocate the structure using spi_res */
3205 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3206 struct_size(rxfer, inserted_transfers, insert)
3207 + extradatasize,
3208 gfp);
3209 if (!rxfer)
3210 return ERR_PTR(-ENOMEM);
3211
3212 /* the release code to invoke before running the generic release */
3213 rxfer->release = release;
3214
3215 /* assign extradata */
3216 if (extradatasize)
3217 rxfer->extradata =
3218 &rxfer->inserted_transfers[insert];
3219
3220 /* init the replaced_transfers list */
3221 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3222
3223 /* assign the list_entry after which we should reinsert
3224 * the @replaced_transfers - it may be spi_message.messages!
3225 */
3226 rxfer->replaced_after = xfer_first->transfer_list.prev;
3227
3228 /* remove the requested number of transfers */
3229 for (i = 0; i < remove; i++) {
3230 /* if the entry after replaced_after it is msg->transfers
3231 * then we have been requested to remove more transfers
3232 * than are in the list
3233 */
3234 if (rxfer->replaced_after->next == &msg->transfers) {
3235 dev_err(&msg->spi->dev,
3236 "requested to remove more spi_transfers than are available\n");
3237 /* insert replaced transfers back into the message */
3238 list_splice(&rxfer->replaced_transfers,
3239 rxfer->replaced_after);
3240
3241 /* free the spi_replace_transfer structure */
3242 spi_res_free(rxfer);
3243
3244 /* and return with an error */
3245 return ERR_PTR(-EINVAL);
3246 }
3247
3248 /* remove the entry after replaced_after from list of
3249 * transfers and add it to list of replaced_transfers
3250 */
3251 list_move_tail(rxfer->replaced_after->next,
3252 &rxfer->replaced_transfers);
3253 }
3254
3255 /* create copy of the given xfer with identical settings
3256 * based on the first transfer to get removed
3257 */
3258 for (i = 0; i < insert; i++) {
3259 /* we need to run in reverse order */
3260 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3261
3262 /* copy all spi_transfer data */
3263 memcpy(xfer, xfer_first, sizeof(*xfer));
3264
3265 /* add to list */
3266 list_add(&xfer->transfer_list, rxfer->replaced_after);
3267
3268 /* clear cs_change and delay for all but the last */
3269 if (i) {
3270 xfer->cs_change = false;
3271 xfer->delay.value = 0;
3272 }
3273 }
3274
3275 /* set up inserted */
3276 rxfer->inserted = insert;
3277
3278 /* and register it with spi_res/spi_message */
3279 spi_res_add(msg, rxfer);
3280
3281 return rxfer;
3282}
3283EXPORT_SYMBOL_GPL(spi_replace_transfers);
3284
3285static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3286 struct spi_message *msg,
3287 struct spi_transfer **xferp,
3288 size_t maxsize,
3289 gfp_t gfp)
3290{
3291 struct spi_transfer *xfer = *xferp, *xfers;
3292 struct spi_replaced_transfers *srt;
3293 size_t offset;
3294 size_t count, i;
3295
3296 /* calculate how many we have to replace */
3297 count = DIV_ROUND_UP(xfer->len, maxsize);
3298
3299 /* create replacement */
3300 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3301 if (IS_ERR(srt))
3302 return PTR_ERR(srt);
3303 xfers = srt->inserted_transfers;
3304
3305 /* now handle each of those newly inserted spi_transfers
3306 * note that the replacements spi_transfers all are preset
3307 * to the same values as *xferp, so tx_buf, rx_buf and len
3308 * are all identical (as well as most others)
3309 * so we just have to fix up len and the pointers.
3310 *
3311 * this also includes support for the depreciated
3312 * spi_message.is_dma_mapped interface
3313 */
3314
3315 /* the first transfer just needs the length modified, so we
3316 * run it outside the loop
3317 */
3318 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3319
3320 /* all the others need rx_buf/tx_buf also set */
3321 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3322 /* update rx_buf, tx_buf and dma */
3323 if (xfers[i].rx_buf)
3324 xfers[i].rx_buf += offset;
3325 if (xfers[i].rx_dma)
3326 xfers[i].rx_dma += offset;
3327 if (xfers[i].tx_buf)
3328 xfers[i].tx_buf += offset;
3329 if (xfers[i].tx_dma)
3330 xfers[i].tx_dma += offset;
3331
3332 /* update length */
3333 xfers[i].len = min(maxsize, xfers[i].len - offset);
3334 }
3335
3336 /* we set up xferp to the last entry we have inserted,
3337 * so that we skip those already split transfers
3338 */
3339 *xferp = &xfers[count - 1];
3340
3341 /* increment statistics counters */
3342 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3343 transfers_split_maxsize);
3344 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3345 transfers_split_maxsize);
3346
3347 return 0;
3348}
3349
3350/**
3351 * spi_split_transfers_maxsize - split spi transfers into multiple transfers
3352 * when an individual transfer exceeds a
3353 * certain size
3354 * @ctlr: the @spi_controller for this transfer
3355 * @msg: the @spi_message to transform
3356 * @maxsize: the maximum when to apply this
3357 * @gfp: GFP allocation flags
3358 *
3359 * Return: status of transformation
3360 */
3361int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3362 struct spi_message *msg,
3363 size_t maxsize,
3364 gfp_t gfp)
3365{
3366 struct spi_transfer *xfer;
3367 int ret;
3368
3369 /* iterate over the transfer_list,
3370 * but note that xfer is advanced to the last transfer inserted
3371 * to avoid checking sizes again unnecessarily (also xfer does
3372 * potentiall belong to a different list by the time the
3373 * replacement has happened
3374 */
3375 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3376 if (xfer->len > maxsize) {
3377 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3378 maxsize, gfp);
3379 if (ret)
3380 return ret;
3381 }
3382 }
3383
3384 return 0;
3385}
3386EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3387
3388/*-------------------------------------------------------------------------*/
3389
3390/* Core methods for SPI controller protocol drivers. Some of the
3391 * other core methods are currently defined as inline functions.
3392 */
3393
3394static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3395 u8 bits_per_word)
3396{
3397 if (ctlr->bits_per_word_mask) {
3398 /* Only 32 bits fit in the mask */
3399 if (bits_per_word > 32)
3400 return -EINVAL;
3401 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3402 return -EINVAL;
3403 }
3404
3405 return 0;
3406}
3407
3408/**
3409 * spi_setup - setup SPI mode and clock rate
3410 * @spi: the device whose settings are being modified
3411 * Context: can sleep, and no requests are queued to the device
3412 *
3413 * SPI protocol drivers may need to update the transfer mode if the
3414 * device doesn't work with its default. They may likewise need
3415 * to update clock rates or word sizes from initial values. This function
3416 * changes those settings, and must be called from a context that can sleep.
3417 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3418 * effect the next time the device is selected and data is transferred to
3419 * or from it. When this function returns, the spi device is deselected.
3420 *
3421 * Note that this call will fail if the protocol driver specifies an option
3422 * that the underlying controller or its driver does not support. For
3423 * example, not all hardware supports wire transfers using nine bit words,
3424 * LSB-first wire encoding, or active-high chipselects.
3425 *
3426 * Return: zero on success, else a negative error code.
3427 */
3428int spi_setup(struct spi_device *spi)
3429{
3430 unsigned bad_bits, ugly_bits;
3431 int status;
3432
3433 /*
3434 * check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO
3435 * are set at the same time
3436 */
3437 if ((hweight_long(spi->mode &
3438 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||
3439 (hweight_long(spi->mode &
3440 (SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {
3441 dev_err(&spi->dev,
3442 "setup: can not select any two of dual, quad and no-rx/tx at the same time\n");
3443 return -EINVAL;
3444 }
3445 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3446 */
3447 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3448 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3449 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3450 return -EINVAL;
3451 /* help drivers fail *cleanly* when they need options
3452 * that aren't supported with their current controller
3453 * SPI_CS_WORD has a fallback software implementation,
3454 * so it is ignored here.
3455 */
3456 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |
3457 SPI_NO_TX | SPI_NO_RX);
3458 /* nothing prevents from working with active-high CS in case if it
3459 * is driven by GPIO.
3460 */
3461 if (gpio_is_valid(spi->cs_gpio))
3462 bad_bits &= ~SPI_CS_HIGH;
3463 ugly_bits = bad_bits &
3464 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3465 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3466 if (ugly_bits) {
3467 dev_warn(&spi->dev,
3468 "setup: ignoring unsupported mode bits %x\n",
3469 ugly_bits);
3470 spi->mode &= ~ugly_bits;
3471 bad_bits &= ~ugly_bits;
3472 }
3473 if (bad_bits) {
3474 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3475 bad_bits);
3476 return -EINVAL;
3477 }
3478
3479 if (!spi->bits_per_word)
3480 spi->bits_per_word = 8;
3481
3482 status = __spi_validate_bits_per_word(spi->controller,
3483 spi->bits_per_word);
3484 if (status)
3485 return status;
3486
3487 if (spi->controller->max_speed_hz &&
3488 (!spi->max_speed_hz ||
3489 spi->max_speed_hz > spi->controller->max_speed_hz))
3490 spi->max_speed_hz = spi->controller->max_speed_hz;
3491
3492 mutex_lock(&spi->controller->io_mutex);
3493
3494 if (spi->controller->setup) {
3495 status = spi->controller->setup(spi);
3496 if (status) {
3497 mutex_unlock(&spi->controller->io_mutex);
3498 dev_err(&spi->controller->dev, "Failed to setup device: %d\n",
3499 status);
3500 return status;
3501 }
3502 }
3503
3504 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3505 status = pm_runtime_get_sync(spi->controller->dev.parent);
3506 if (status < 0) {
3507 mutex_unlock(&spi->controller->io_mutex);
3508 pm_runtime_put_noidle(spi->controller->dev.parent);
3509 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3510 status);
3511 return status;
3512 }
3513
3514 /*
3515 * We do not want to return positive value from pm_runtime_get,
3516 * there are many instances of devices calling spi_setup() and
3517 * checking for a non-zero return value instead of a negative
3518 * return value.
3519 */
3520 status = 0;
3521
3522 spi_set_cs(spi, false, true);
3523 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3524 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3525 } else {
3526 spi_set_cs(spi, false, true);
3527 }
3528
3529 mutex_unlock(&spi->controller->io_mutex);
3530
3531 if (spi->rt && !spi->controller->rt) {
3532 spi->controller->rt = true;
3533 spi_set_thread_rt(spi->controller);
3534 }
3535
3536 trace_spi_setup(spi, status);
3537
3538 dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3539 spi->mode & SPI_MODE_X_MASK,
3540 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3541 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3542 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3543 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3544 spi->bits_per_word, spi->max_speed_hz,
3545 status);
3546
3547 return status;
3548}
3549EXPORT_SYMBOL_GPL(spi_setup);
3550
3551static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3552 struct spi_device *spi)
3553{
3554 int delay1, delay2;
3555
3556 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3557 if (delay1 < 0)
3558 return delay1;
3559
3560 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3561 if (delay2 < 0)
3562 return delay2;
3563
3564 if (delay1 < delay2)
3565 memcpy(&xfer->word_delay, &spi->word_delay,
3566 sizeof(xfer->word_delay));
3567
3568 return 0;
3569}
3570
3571static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3572{
3573 struct spi_controller *ctlr = spi->controller;
3574 struct spi_transfer *xfer;
3575 int w_size;
3576
3577 if (list_empty(&message->transfers))
3578 return -EINVAL;
3579
3580 /* If an SPI controller does not support toggling the CS line on each
3581 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3582 * for the CS line, we can emulate the CS-per-word hardware function by
3583 * splitting transfers into one-word transfers and ensuring that
3584 * cs_change is set for each transfer.
3585 */
3586 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3587 spi->cs_gpiod ||
3588 gpio_is_valid(spi->cs_gpio))) {
3589 size_t maxsize;
3590 int ret;
3591
3592 maxsize = (spi->bits_per_word + 7) / 8;
3593
3594 /* spi_split_transfers_maxsize() requires message->spi */
3595 message->spi = spi;
3596
3597 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3598 GFP_KERNEL);
3599 if (ret)
3600 return ret;
3601
3602 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3603 /* don't change cs_change on the last entry in the list */
3604 if (list_is_last(&xfer->transfer_list, &message->transfers))
3605 break;
3606 xfer->cs_change = 1;
3607 }
3608 }
3609
3610 /* Half-duplex links include original MicroWire, and ones with
3611 * only one data pin like SPI_3WIRE (switches direction) or where
3612 * either MOSI or MISO is missing. They can also be caused by
3613 * software limitations.
3614 */
3615 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3616 (spi->mode & SPI_3WIRE)) {
3617 unsigned flags = ctlr->flags;
3618
3619 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3620 if (xfer->rx_buf && xfer->tx_buf)
3621 return -EINVAL;
3622 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3623 return -EINVAL;
3624 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3625 return -EINVAL;
3626 }
3627 }
3628
3629 /**
3630 * Set transfer bits_per_word and max speed as spi device default if
3631 * it is not set for this transfer.
3632 * Set transfer tx_nbits and rx_nbits as single transfer default
3633 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3634 * Ensure transfer word_delay is at least as long as that required by
3635 * device itself.
3636 */
3637 message->frame_length = 0;
3638 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3639 xfer->effective_speed_hz = 0;
3640 message->frame_length += xfer->len;
3641 if (!xfer->bits_per_word)
3642 xfer->bits_per_word = spi->bits_per_word;
3643
3644 if (!xfer->speed_hz)
3645 xfer->speed_hz = spi->max_speed_hz;
3646
3647 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3648 xfer->speed_hz = ctlr->max_speed_hz;
3649
3650 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3651 return -EINVAL;
3652
3653 /*
3654 * SPI transfer length should be multiple of SPI word size
3655 * where SPI word size should be power-of-two multiple
3656 */
3657 if (xfer->bits_per_word <= 8)
3658 w_size = 1;
3659 else if (xfer->bits_per_word <= 16)
3660 w_size = 2;
3661 else
3662 w_size = 4;
3663
3664 /* No partial transfers accepted */
3665 if (xfer->len % w_size)
3666 return -EINVAL;
3667
3668 if (xfer->speed_hz && ctlr->min_speed_hz &&
3669 xfer->speed_hz < ctlr->min_speed_hz)
3670 return -EINVAL;
3671
3672 if (xfer->tx_buf && !xfer->tx_nbits)
3673 xfer->tx_nbits = SPI_NBITS_SINGLE;
3674 if (xfer->rx_buf && !xfer->rx_nbits)
3675 xfer->rx_nbits = SPI_NBITS_SINGLE;
3676 /* check transfer tx/rx_nbits:
3677 * 1. check the value matches one of single, dual and quad
3678 * 2. check tx/rx_nbits match the mode in spi_device
3679 */
3680 if (xfer->tx_buf) {
3681 if (spi->mode & SPI_NO_TX)
3682 return -EINVAL;
3683 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3684 xfer->tx_nbits != SPI_NBITS_DUAL &&
3685 xfer->tx_nbits != SPI_NBITS_QUAD)
3686 return -EINVAL;
3687 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3688 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3689 return -EINVAL;
3690 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3691 !(spi->mode & SPI_TX_QUAD))
3692 return -EINVAL;
3693 }
3694 /* check transfer rx_nbits */
3695 if (xfer->rx_buf) {
3696 if (spi->mode & SPI_NO_RX)
3697 return -EINVAL;
3698 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3699 xfer->rx_nbits != SPI_NBITS_DUAL &&
3700 xfer->rx_nbits != SPI_NBITS_QUAD)
3701 return -EINVAL;
3702 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3703 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3704 return -EINVAL;
3705 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3706 !(spi->mode & SPI_RX_QUAD))
3707 return -EINVAL;
3708 }
3709
3710 if (_spi_xfer_word_delay_update(xfer, spi))
3711 return -EINVAL;
3712 }
3713
3714 message->status = -EINPROGRESS;
3715
3716 return 0;
3717}
3718
3719static int __spi_async(struct spi_device *spi, struct spi_message *message)
3720{
3721 struct spi_controller *ctlr = spi->controller;
3722 struct spi_transfer *xfer;
3723
3724 /*
3725 * Some controllers do not support doing regular SPI transfers. Return
3726 * ENOTSUPP when this is the case.
3727 */
3728 if (!ctlr->transfer)
3729 return -ENOTSUPP;
3730
3731 message->spi = spi;
3732
3733 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3734 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3735
3736 trace_spi_message_submit(message);
3737
3738 if (!ctlr->ptp_sts_supported) {
3739 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3740 xfer->ptp_sts_word_pre = 0;
3741 ptp_read_system_prets(xfer->ptp_sts);
3742 }
3743 }
3744
3745 return ctlr->transfer(spi, message);
3746}
3747
3748/**
3749 * spi_async - asynchronous SPI transfer
3750 * @spi: device with which data will be exchanged
3751 * @message: describes the data transfers, including completion callback
3752 * Context: any (irqs may be blocked, etc)
3753 *
3754 * This call may be used in_irq and other contexts which can't sleep,
3755 * as well as from task contexts which can sleep.
3756 *
3757 * The completion callback is invoked in a context which can't sleep.
3758 * Before that invocation, the value of message->status is undefined.
3759 * When the callback is issued, message->status holds either zero (to
3760 * indicate complete success) or a negative error code. After that
3761 * callback returns, the driver which issued the transfer request may
3762 * deallocate the associated memory; it's no longer in use by any SPI
3763 * core or controller driver code.
3764 *
3765 * Note that although all messages to a spi_device are handled in
3766 * FIFO order, messages may go to different devices in other orders.
3767 * Some device might be higher priority, or have various "hard" access
3768 * time requirements, for example.
3769 *
3770 * On detection of any fault during the transfer, processing of
3771 * the entire message is aborted, and the device is deselected.
3772 * Until returning from the associated message completion callback,
3773 * no other spi_message queued to that device will be processed.
3774 * (This rule applies equally to all the synchronous transfer calls,
3775 * which are wrappers around this core asynchronous primitive.)
3776 *
3777 * Return: zero on success, else a negative error code.
3778 */
3779int spi_async(struct spi_device *spi, struct spi_message *message)
3780{
3781 struct spi_controller *ctlr = spi->controller;
3782 int ret;
3783 unsigned long flags;
3784
3785 ret = __spi_validate(spi, message);
3786 if (ret != 0)
3787 return ret;
3788
3789 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3790
3791 if (ctlr->bus_lock_flag)
3792 ret = -EBUSY;
3793 else
3794 ret = __spi_async(spi, message);
3795
3796 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3797
3798 return ret;
3799}
3800EXPORT_SYMBOL_GPL(spi_async);
3801
3802/**
3803 * spi_async_locked - version of spi_async with exclusive bus usage
3804 * @spi: device with which data will be exchanged
3805 * @message: describes the data transfers, including completion callback
3806 * Context: any (irqs may be blocked, etc)
3807 *
3808 * This call may be used in_irq and other contexts which can't sleep,
3809 * as well as from task contexts which can sleep.
3810 *
3811 * The completion callback is invoked in a context which can't sleep.
3812 * Before that invocation, the value of message->status is undefined.
3813 * When the callback is issued, message->status holds either zero (to
3814 * indicate complete success) or a negative error code. After that
3815 * callback returns, the driver which issued the transfer request may
3816 * deallocate the associated memory; it's no longer in use by any SPI
3817 * core or controller driver code.
3818 *
3819 * Note that although all messages to a spi_device are handled in
3820 * FIFO order, messages may go to different devices in other orders.
3821 * Some device might be higher priority, or have various "hard" access
3822 * time requirements, for example.
3823 *
3824 * On detection of any fault during the transfer, processing of
3825 * the entire message is aborted, and the device is deselected.
3826 * Until returning from the associated message completion callback,
3827 * no other spi_message queued to that device will be processed.
3828 * (This rule applies equally to all the synchronous transfer calls,
3829 * which are wrappers around this core asynchronous primitive.)
3830 *
3831 * Return: zero on success, else a negative error code.
3832 */
3833int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3834{
3835 struct spi_controller *ctlr = spi->controller;
3836 int ret;
3837 unsigned long flags;
3838
3839 ret = __spi_validate(spi, message);
3840 if (ret != 0)
3841 return ret;
3842
3843 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3844
3845 ret = __spi_async(spi, message);
3846
3847 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3848
3849 return ret;
3850
3851}
3852EXPORT_SYMBOL_GPL(spi_async_locked);
3853
3854/*-------------------------------------------------------------------------*/
3855
3856/* Utility methods for SPI protocol drivers, layered on
3857 * top of the core. Some other utility methods are defined as
3858 * inline functions.
3859 */
3860
3861static void spi_complete(void *arg)
3862{
3863 complete(arg);
3864}
3865
3866static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3867{
3868 DECLARE_COMPLETION_ONSTACK(done);
3869 int status;
3870 struct spi_controller *ctlr = spi->controller;
3871 unsigned long flags;
3872
3873 status = __spi_validate(spi, message);
3874 if (status != 0)
3875 return status;
3876
3877 message->complete = spi_complete;
3878 message->context = &done;
3879 message->spi = spi;
3880
3881 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3882 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3883
3884 /* If we're not using the legacy transfer method then we will
3885 * try to transfer in the calling context so special case.
3886 * This code would be less tricky if we could remove the
3887 * support for driver implemented message queues.
3888 */
3889 if (ctlr->transfer == spi_queued_transfer) {
3890 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3891
3892 trace_spi_message_submit(message);
3893
3894 status = __spi_queued_transfer(spi, message, false);
3895
3896 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3897 } else {
3898 status = spi_async_locked(spi, message);
3899 }
3900
3901 if (status == 0) {
3902 /* Push out the messages in the calling context if we
3903 * can.
3904 */
3905 if (ctlr->transfer == spi_queued_transfer) {
3906 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3907 spi_sync_immediate);
3908 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3909 spi_sync_immediate);
3910 __spi_pump_messages(ctlr, false);
3911 }
3912
3913 wait_for_completion(&done);
3914 status = message->status;
3915 }
3916 message->context = NULL;
3917 return status;
3918}
3919
3920/**
3921 * spi_sync - blocking/synchronous SPI data transfers
3922 * @spi: device with which data will be exchanged
3923 * @message: describes the data transfers
3924 * Context: can sleep
3925 *
3926 * This call may only be used from a context that may sleep. The sleep
3927 * is non-interruptible, and has no timeout. Low-overhead controller
3928 * drivers may DMA directly into and out of the message buffers.
3929 *
3930 * Note that the SPI device's chip select is active during the message,
3931 * and then is normally disabled between messages. Drivers for some
3932 * frequently-used devices may want to minimize costs of selecting a chip,
3933 * by leaving it selected in anticipation that the next message will go
3934 * to the same chip. (That may increase power usage.)
3935 *
3936 * Also, the caller is guaranteeing that the memory associated with the
3937 * message will not be freed before this call returns.
3938 *
3939 * Return: zero on success, else a negative error code.
3940 */
3941int spi_sync(struct spi_device *spi, struct spi_message *message)
3942{
3943 int ret;
3944
3945 mutex_lock(&spi->controller->bus_lock_mutex);
3946 ret = __spi_sync(spi, message);
3947 mutex_unlock(&spi->controller->bus_lock_mutex);
3948
3949 return ret;
3950}
3951EXPORT_SYMBOL_GPL(spi_sync);
3952
3953/**
3954 * spi_sync_locked - version of spi_sync with exclusive bus usage
3955 * @spi: device with which data will be exchanged
3956 * @message: describes the data transfers
3957 * Context: can sleep
3958 *
3959 * This call may only be used from a context that may sleep. The sleep
3960 * is non-interruptible, and has no timeout. Low-overhead controller
3961 * drivers may DMA directly into and out of the message buffers.
3962 *
3963 * This call should be used by drivers that require exclusive access to the
3964 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3965 * be released by a spi_bus_unlock call when the exclusive access is over.
3966 *
3967 * Return: zero on success, else a negative error code.
3968 */
3969int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3970{
3971 return __spi_sync(spi, message);
3972}
3973EXPORT_SYMBOL_GPL(spi_sync_locked);
3974
3975/**
3976 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3977 * @ctlr: SPI bus master that should be locked for exclusive bus access
3978 * Context: can sleep
3979 *
3980 * This call may only be used from a context that may sleep. The sleep
3981 * is non-interruptible, and has no timeout.
3982 *
3983 * This call should be used by drivers that require exclusive access to the
3984 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3985 * exclusive access is over. Data transfer must be done by spi_sync_locked
3986 * and spi_async_locked calls when the SPI bus lock is held.
3987 *
3988 * Return: always zero.
3989 */
3990int spi_bus_lock(struct spi_controller *ctlr)
3991{
3992 unsigned long flags;
3993
3994 mutex_lock(&ctlr->bus_lock_mutex);
3995
3996 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3997 ctlr->bus_lock_flag = 1;
3998 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3999
4000 /* mutex remains locked until spi_bus_unlock is called */
4001
4002 return 0;
4003}
4004EXPORT_SYMBOL_GPL(spi_bus_lock);
4005
4006/**
4007 * spi_bus_unlock - release the lock for exclusive SPI bus usage
4008 * @ctlr: SPI bus master that was locked for exclusive bus access
4009 * Context: can sleep
4010 *
4011 * This call may only be used from a context that may sleep. The sleep
4012 * is non-interruptible, and has no timeout.
4013 *
4014 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
4015 * call.
4016 *
4017 * Return: always zero.
4018 */
4019int spi_bus_unlock(struct spi_controller *ctlr)
4020{
4021 ctlr->bus_lock_flag = 0;
4022
4023 mutex_unlock(&ctlr->bus_lock_mutex);
4024
4025 return 0;
4026}
4027EXPORT_SYMBOL_GPL(spi_bus_unlock);
4028
4029/* portable code must never pass more than 32 bytes */
4030#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
4031
4032static u8 *buf;
4033
4034/**
4035 * spi_write_then_read - SPI synchronous write followed by read
4036 * @spi: device with which data will be exchanged
4037 * @txbuf: data to be written (need not be dma-safe)
4038 * @n_tx: size of txbuf, in bytes
4039 * @rxbuf: buffer into which data will be read (need not be dma-safe)
4040 * @n_rx: size of rxbuf, in bytes
4041 * Context: can sleep
4042 *
4043 * This performs a half duplex MicroWire style transaction with the
4044 * device, sending txbuf and then reading rxbuf. The return value
4045 * is zero for success, else a negative errno status code.
4046 * This call may only be used from a context that may sleep.
4047 *
4048 * Parameters to this routine are always copied using a small buffer.
4049 * Performance-sensitive or bulk transfer code should instead use
4050 * spi_{async,sync}() calls with dma-safe buffers.
4051 *
4052 * Return: zero on success, else a negative error code.
4053 */
4054int spi_write_then_read(struct spi_device *spi,
4055 const void *txbuf, unsigned n_tx,
4056 void *rxbuf, unsigned n_rx)
4057{
4058 static DEFINE_MUTEX(lock);
4059
4060 int status;
4061 struct spi_message message;
4062 struct spi_transfer x[2];
4063 u8 *local_buf;
4064
4065 /* Use preallocated DMA-safe buffer if we can. We can't avoid
4066 * copying here, (as a pure convenience thing), but we can
4067 * keep heap costs out of the hot path unless someone else is
4068 * using the pre-allocated buffer or the transfer is too large.
4069 */
4070 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
4071 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
4072 GFP_KERNEL | GFP_DMA);
4073 if (!local_buf)
4074 return -ENOMEM;
4075 } else {
4076 local_buf = buf;
4077 }
4078
4079 spi_message_init(&message);
4080 memset(x, 0, sizeof(x));
4081 if (n_tx) {
4082 x[0].len = n_tx;
4083 spi_message_add_tail(&x[0], &message);
4084 }
4085 if (n_rx) {
4086 x[1].len = n_rx;
4087 spi_message_add_tail(&x[1], &message);
4088 }
4089
4090 memcpy(local_buf, txbuf, n_tx);
4091 x[0].tx_buf = local_buf;
4092 x[1].rx_buf = local_buf + n_tx;
4093
4094 /* do the i/o */
4095 status = spi_sync(spi, &message);
4096 if (status == 0)
4097 memcpy(rxbuf, x[1].rx_buf, n_rx);
4098
4099 if (x[0].tx_buf == buf)
4100 mutex_unlock(&lock);
4101 else
4102 kfree(local_buf);
4103
4104 return status;
4105}
4106EXPORT_SYMBOL_GPL(spi_write_then_read);
4107
4108/*-------------------------------------------------------------------------*/
4109
4110#if IS_ENABLED(CONFIG_OF)
4111/* must call put_device() when done with returned spi_device device */
4112struct spi_device *of_find_spi_device_by_node(struct device_node *node)
4113{
4114 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
4115
4116 return dev ? to_spi_device(dev) : NULL;
4117}
4118EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
4119#endif /* IS_ENABLED(CONFIG_OF) */
4120
4121#if IS_ENABLED(CONFIG_OF_DYNAMIC)
4122/* the spi controllers are not using spi_bus, so we find it with another way */
4123static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
4124{
4125 struct device *dev;
4126
4127 dev = class_find_device_by_of_node(&spi_master_class, node);
4128 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4129 dev = class_find_device_by_of_node(&spi_slave_class, node);
4130 if (!dev)
4131 return NULL;
4132
4133 /* reference got in class_find_device */
4134 return container_of(dev, struct spi_controller, dev);
4135}
4136
4137static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4138 void *arg)
4139{
4140 struct of_reconfig_data *rd = arg;
4141 struct spi_controller *ctlr;
4142 struct spi_device *spi;
4143
4144 switch (of_reconfig_get_state_change(action, arg)) {
4145 case OF_RECONFIG_CHANGE_ADD:
4146 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4147 if (ctlr == NULL)
4148 return NOTIFY_OK; /* not for us */
4149
4150 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4151 put_device(&ctlr->dev);
4152 return NOTIFY_OK;
4153 }
4154
4155 spi = of_register_spi_device(ctlr, rd->dn);
4156 put_device(&ctlr->dev);
4157
4158 if (IS_ERR(spi)) {
4159 pr_err("%s: failed to create for '%pOF'\n",
4160 __func__, rd->dn);
4161 of_node_clear_flag(rd->dn, OF_POPULATED);
4162 return notifier_from_errno(PTR_ERR(spi));
4163 }
4164 break;
4165
4166 case OF_RECONFIG_CHANGE_REMOVE:
4167 /* already depopulated? */
4168 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4169 return NOTIFY_OK;
4170
4171 /* find our device by node */
4172 spi = of_find_spi_device_by_node(rd->dn);
4173 if (spi == NULL)
4174 return NOTIFY_OK; /* no? not meant for us */
4175
4176 /* unregister takes one ref away */
4177 spi_unregister_device(spi);
4178
4179 /* and put the reference of the find */
4180 put_device(&spi->dev);
4181 break;
4182 }
4183
4184 return NOTIFY_OK;
4185}
4186
4187static struct notifier_block spi_of_notifier = {
4188 .notifier_call = of_spi_notify,
4189};
4190#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4191extern struct notifier_block spi_of_notifier;
4192#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4193
4194#if IS_ENABLED(CONFIG_ACPI)
4195static int spi_acpi_controller_match(struct device *dev, const void *data)
4196{
4197 return ACPI_COMPANION(dev->parent) == data;
4198}
4199
4200static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4201{
4202 struct device *dev;
4203
4204 dev = class_find_device(&spi_master_class, NULL, adev,
4205 spi_acpi_controller_match);
4206 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4207 dev = class_find_device(&spi_slave_class, NULL, adev,
4208 spi_acpi_controller_match);
4209 if (!dev)
4210 return NULL;
4211
4212 return container_of(dev, struct spi_controller, dev);
4213}
4214
4215static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4216{
4217 struct device *dev;
4218
4219 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4220 return to_spi_device(dev);
4221}
4222
4223static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4224 void *arg)
4225{
4226 struct acpi_device *adev = arg;
4227 struct spi_controller *ctlr;
4228 struct spi_device *spi;
4229
4230 switch (value) {
4231 case ACPI_RECONFIG_DEVICE_ADD:
4232 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4233 if (!ctlr)
4234 break;
4235
4236 acpi_register_spi_device(ctlr, adev);
4237 put_device(&ctlr->dev);
4238 break;
4239 case ACPI_RECONFIG_DEVICE_REMOVE:
4240 if (!acpi_device_enumerated(adev))
4241 break;
4242
4243 spi = acpi_spi_find_device_by_adev(adev);
4244 if (!spi)
4245 break;
4246
4247 spi_unregister_device(spi);
4248 put_device(&spi->dev);
4249 break;
4250 }
4251
4252 return NOTIFY_OK;
4253}
4254
4255static struct notifier_block spi_acpi_notifier = {
4256 .notifier_call = acpi_spi_notify,
4257};
4258#else
4259extern struct notifier_block spi_acpi_notifier;
4260#endif
4261
4262static int __init spi_init(void)
4263{
4264 int status;
4265
4266 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4267 if (!buf) {
4268 status = -ENOMEM;
4269 goto err0;
4270 }
4271
4272 status = bus_register(&spi_bus_type);
4273 if (status < 0)
4274 goto err1;
4275
4276 status = class_register(&spi_master_class);
4277 if (status < 0)
4278 goto err2;
4279
4280 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4281 status = class_register(&spi_slave_class);
4282 if (status < 0)
4283 goto err3;
4284 }
4285
4286 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4287 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4288 if (IS_ENABLED(CONFIG_ACPI))
4289 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4290
4291 return 0;
4292
4293err3:
4294 class_unregister(&spi_master_class);
4295err2:
4296 bus_unregister(&spi_bus_type);
4297err1:
4298 kfree(buf);
4299 buf = NULL;
4300err0:
4301 return status;
4302}
4303
4304/* board_info is normally registered in arch_initcall(),
4305 * but even essential drivers wait till later
4306 *
4307 * REVISIT only boardinfo really needs static linking. the rest (device and
4308 * driver registration) _could_ be dynamically linked (modular) ... costs
4309 * include needing to have boardinfo data structures be much more public.
4310 */
4311postcore_initcall(spi_init);