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