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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 controllers may cleanup for released devices */
51 if (spi->controller->cleanup)
52 spi->controller->cleanup(spi);
53
54 spi_controller_put(spi->controller);
55 kfree(spi->driver_override);
56 kfree(spi);
57}
58
59static ssize_t
60modalias_show(struct device *dev, struct device_attribute *a, char *buf)
61{
62 const struct spi_device *spi = to_spi_device(dev);
63 int len;
64
65 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
66 if (len != -ENODEV)
67 return len;
68
69 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
70}
71static DEVICE_ATTR_RO(modalias);
72
73static ssize_t driver_override_store(struct device *dev,
74 struct device_attribute *a,
75 const char *buf, size_t count)
76{
77 struct spi_device *spi = to_spi_device(dev);
78 const char *end = memchr(buf, '\n', count);
79 const size_t len = end ? end - buf : count;
80 const char *driver_override, *old;
81
82 /* We need to keep extra room for a newline when displaying value */
83 if (len >= (PAGE_SIZE - 1))
84 return -EINVAL;
85
86 driver_override = kstrndup(buf, len, GFP_KERNEL);
87 if (!driver_override)
88 return -ENOMEM;
89
90 device_lock(dev);
91 old = spi->driver_override;
92 if (len) {
93 spi->driver_override = driver_override;
94 } else {
95 /* Empty string, disable driver override */
96 spi->driver_override = NULL;
97 kfree(driver_override);
98 }
99 device_unlock(dev);
100 kfree(old);
101
102 return count;
103}
104
105static ssize_t driver_override_show(struct device *dev,
106 struct device_attribute *a, char *buf)
107{
108 const struct spi_device *spi = to_spi_device(dev);
109 ssize_t len;
110
111 device_lock(dev);
112 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
113 device_unlock(dev);
114 return len;
115}
116static DEVICE_ATTR_RW(driver_override);
117
118#define SPI_STATISTICS_ATTRS(field, file) \
119static ssize_t spi_controller_##field##_show(struct device *dev, \
120 struct device_attribute *attr, \
121 char *buf) \
122{ \
123 struct spi_controller *ctlr = container_of(dev, \
124 struct spi_controller, dev); \
125 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
126} \
127static struct device_attribute dev_attr_spi_controller_##field = { \
128 .attr = { .name = file, .mode = 0444 }, \
129 .show = spi_controller_##field##_show, \
130}; \
131static ssize_t spi_device_##field##_show(struct device *dev, \
132 struct device_attribute *attr, \
133 char *buf) \
134{ \
135 struct spi_device *spi = to_spi_device(dev); \
136 return spi_statistics_##field##_show(&spi->statistics, buf); \
137} \
138static struct device_attribute dev_attr_spi_device_##field = { \
139 .attr = { .name = file, .mode = 0444 }, \
140 .show = spi_device_##field##_show, \
141}
142
143#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
144static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
145 char *buf) \
146{ \
147 unsigned long flags; \
148 ssize_t len; \
149 spin_lock_irqsave(&stat->lock, flags); \
150 len = sprintf(buf, format_string, stat->field); \
151 spin_unlock_irqrestore(&stat->lock, flags); \
152 return len; \
153} \
154SPI_STATISTICS_ATTRS(name, file)
155
156#define SPI_STATISTICS_SHOW(field, format_string) \
157 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
158 field, format_string)
159
160SPI_STATISTICS_SHOW(messages, "%lu");
161SPI_STATISTICS_SHOW(transfers, "%lu");
162SPI_STATISTICS_SHOW(errors, "%lu");
163SPI_STATISTICS_SHOW(timedout, "%lu");
164
165SPI_STATISTICS_SHOW(spi_sync, "%lu");
166SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
167SPI_STATISTICS_SHOW(spi_async, "%lu");
168
169SPI_STATISTICS_SHOW(bytes, "%llu");
170SPI_STATISTICS_SHOW(bytes_rx, "%llu");
171SPI_STATISTICS_SHOW(bytes_tx, "%llu");
172
173#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
174 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
175 "transfer_bytes_histo_" number, \
176 transfer_bytes_histo[index], "%lu")
177SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
178SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
179SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
180SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
181SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
182SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
183SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
184SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
185SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
186SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
187SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
188SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
189SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
190SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
191SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
192SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
193SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
194
195SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
196
197static struct attribute *spi_dev_attrs[] = {
198 &dev_attr_modalias.attr,
199 &dev_attr_driver_override.attr,
200 NULL,
201};
202
203static const struct attribute_group spi_dev_group = {
204 .attrs = spi_dev_attrs,
205};
206
207static struct attribute *spi_device_statistics_attrs[] = {
208 &dev_attr_spi_device_messages.attr,
209 &dev_attr_spi_device_transfers.attr,
210 &dev_attr_spi_device_errors.attr,
211 &dev_attr_spi_device_timedout.attr,
212 &dev_attr_spi_device_spi_sync.attr,
213 &dev_attr_spi_device_spi_sync_immediate.attr,
214 &dev_attr_spi_device_spi_async.attr,
215 &dev_attr_spi_device_bytes.attr,
216 &dev_attr_spi_device_bytes_rx.attr,
217 &dev_attr_spi_device_bytes_tx.attr,
218 &dev_attr_spi_device_transfer_bytes_histo0.attr,
219 &dev_attr_spi_device_transfer_bytes_histo1.attr,
220 &dev_attr_spi_device_transfer_bytes_histo2.attr,
221 &dev_attr_spi_device_transfer_bytes_histo3.attr,
222 &dev_attr_spi_device_transfer_bytes_histo4.attr,
223 &dev_attr_spi_device_transfer_bytes_histo5.attr,
224 &dev_attr_spi_device_transfer_bytes_histo6.attr,
225 &dev_attr_spi_device_transfer_bytes_histo7.attr,
226 &dev_attr_spi_device_transfer_bytes_histo8.attr,
227 &dev_attr_spi_device_transfer_bytes_histo9.attr,
228 &dev_attr_spi_device_transfer_bytes_histo10.attr,
229 &dev_attr_spi_device_transfer_bytes_histo11.attr,
230 &dev_attr_spi_device_transfer_bytes_histo12.attr,
231 &dev_attr_spi_device_transfer_bytes_histo13.attr,
232 &dev_attr_spi_device_transfer_bytes_histo14.attr,
233 &dev_attr_spi_device_transfer_bytes_histo15.attr,
234 &dev_attr_spi_device_transfer_bytes_histo16.attr,
235 &dev_attr_spi_device_transfers_split_maxsize.attr,
236 NULL,
237};
238
239static const struct attribute_group spi_device_statistics_group = {
240 .name = "statistics",
241 .attrs = spi_device_statistics_attrs,
242};
243
244static const struct attribute_group *spi_dev_groups[] = {
245 &spi_dev_group,
246 &spi_device_statistics_group,
247 NULL,
248};
249
250static struct attribute *spi_controller_statistics_attrs[] = {
251 &dev_attr_spi_controller_messages.attr,
252 &dev_attr_spi_controller_transfers.attr,
253 &dev_attr_spi_controller_errors.attr,
254 &dev_attr_spi_controller_timedout.attr,
255 &dev_attr_spi_controller_spi_sync.attr,
256 &dev_attr_spi_controller_spi_sync_immediate.attr,
257 &dev_attr_spi_controller_spi_async.attr,
258 &dev_attr_spi_controller_bytes.attr,
259 &dev_attr_spi_controller_bytes_rx.attr,
260 &dev_attr_spi_controller_bytes_tx.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
274 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
275 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
276 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
277 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
278 &dev_attr_spi_controller_transfers_split_maxsize.attr,
279 NULL,
280};
281
282static const struct attribute_group spi_controller_statistics_group = {
283 .name = "statistics",
284 .attrs = spi_controller_statistics_attrs,
285};
286
287static const struct attribute_group *spi_master_groups[] = {
288 &spi_controller_statistics_group,
289 NULL,
290};
291
292void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
293 struct spi_transfer *xfer,
294 struct spi_controller *ctlr)
295{
296 unsigned long flags;
297 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
298
299 if (l2len < 0)
300 l2len = 0;
301
302 spin_lock_irqsave(&stats->lock, flags);
303
304 stats->transfers++;
305 stats->transfer_bytes_histo[l2len]++;
306
307 stats->bytes += xfer->len;
308 if ((xfer->tx_buf) &&
309 (xfer->tx_buf != ctlr->dummy_tx))
310 stats->bytes_tx += xfer->len;
311 if ((xfer->rx_buf) &&
312 (xfer->rx_buf != ctlr->dummy_rx))
313 stats->bytes_rx += xfer->len;
314
315 spin_unlock_irqrestore(&stats->lock, flags);
316}
317EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
318
319/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
320 * and the sysfs version makes coldplug work too.
321 */
322
323static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
324 const struct spi_device *sdev)
325{
326 while (id->name[0]) {
327 if (!strcmp(sdev->modalias, id->name))
328 return id;
329 id++;
330 }
331 return NULL;
332}
333
334const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
337
338 return spi_match_id(sdrv->id_table, sdev);
339}
340EXPORT_SYMBOL_GPL(spi_get_device_id);
341
342static int spi_match_device(struct device *dev, struct device_driver *drv)
343{
344 const struct spi_device *spi = to_spi_device(dev);
345 const struct spi_driver *sdrv = to_spi_driver(drv);
346
347 /* Check override first, and if set, only use the named driver */
348 if (spi->driver_override)
349 return strcmp(spi->driver_override, drv->name) == 0;
350
351 /* Attempt an OF style match */
352 if (of_driver_match_device(dev, drv))
353 return 1;
354
355 /* Then try ACPI */
356 if (acpi_driver_match_device(dev, drv))
357 return 1;
358
359 if (sdrv->id_table)
360 return !!spi_match_id(sdrv->id_table, spi);
361
362 return strcmp(spi->modalias, drv->name) == 0;
363}
364
365static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
366{
367 const struct spi_device *spi = to_spi_device(dev);
368 int rc;
369
370 rc = acpi_device_uevent_modalias(dev, env);
371 if (rc != -ENODEV)
372 return rc;
373
374 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
375}
376
377struct bus_type spi_bus_type = {
378 .name = "spi",
379 .dev_groups = spi_dev_groups,
380 .match = spi_match_device,
381 .uevent = spi_uevent,
382};
383EXPORT_SYMBOL_GPL(spi_bus_type);
384
385
386static int spi_drv_probe(struct device *dev)
387{
388 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
389 struct spi_device *spi = to_spi_device(dev);
390 int ret;
391
392 ret = of_clk_set_defaults(dev->of_node, false);
393 if (ret)
394 return ret;
395
396 if (dev->of_node) {
397 spi->irq = of_irq_get(dev->of_node, 0);
398 if (spi->irq == -EPROBE_DEFER)
399 return -EPROBE_DEFER;
400 if (spi->irq < 0)
401 spi->irq = 0;
402 }
403
404 ret = dev_pm_domain_attach(dev, true);
405 if (ret)
406 return ret;
407
408 ret = sdrv->probe(spi);
409 if (ret)
410 dev_pm_domain_detach(dev, true);
411
412 return ret;
413}
414
415static int spi_drv_remove(struct device *dev)
416{
417 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
418 int ret;
419
420 ret = sdrv->remove(to_spi_device(dev));
421 dev_pm_domain_detach(dev, true);
422
423 return ret;
424}
425
426static void spi_drv_shutdown(struct device *dev)
427{
428 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
429
430 sdrv->shutdown(to_spi_device(dev));
431}
432
433/**
434 * __spi_register_driver - register a SPI driver
435 * @owner: owner module of the driver to register
436 * @sdrv: the driver to register
437 * Context: can sleep
438 *
439 * Return: zero on success, else a negative error code.
440 */
441int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
442{
443 sdrv->driver.owner = owner;
444 sdrv->driver.bus = &spi_bus_type;
445 if (sdrv->probe)
446 sdrv->driver.probe = spi_drv_probe;
447 if (sdrv->remove)
448 sdrv->driver.remove = spi_drv_remove;
449 if (sdrv->shutdown)
450 sdrv->driver.shutdown = spi_drv_shutdown;
451 return driver_register(&sdrv->driver);
452}
453EXPORT_SYMBOL_GPL(__spi_register_driver);
454
455/*-------------------------------------------------------------------------*/
456
457/* SPI devices should normally not be created by SPI device drivers; that
458 * would make them board-specific. Similarly with SPI controller drivers.
459 * Device registration normally goes into like arch/.../mach.../board-YYY.c
460 * with other readonly (flashable) information about mainboard devices.
461 */
462
463struct boardinfo {
464 struct list_head list;
465 struct spi_board_info board_info;
466};
467
468static LIST_HEAD(board_list);
469static LIST_HEAD(spi_controller_list);
470
471/*
472 * Used to protect add/del operation for board_info list and
473 * spi_controller list, and their matching process
474 * also used to protect object of type struct idr
475 */
476static DEFINE_MUTEX(board_lock);
477
478/*
479 * Prevents addition of devices with same chip select and
480 * addition of devices below an unregistering controller.
481 */
482static DEFINE_MUTEX(spi_add_lock);
483
484/**
485 * spi_alloc_device - Allocate a new SPI device
486 * @ctlr: Controller to which device is connected
487 * Context: can sleep
488 *
489 * Allows a driver to allocate and initialize a spi_device without
490 * registering it immediately. This allows a driver to directly
491 * fill the spi_device with device parameters before calling
492 * spi_add_device() on it.
493 *
494 * Caller is responsible to call spi_add_device() on the returned
495 * spi_device structure to add it to the SPI controller. If the caller
496 * needs to discard the spi_device without adding it, then it should
497 * call spi_dev_put() on it.
498 *
499 * Return: a pointer to the new device, or NULL.
500 */
501struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
502{
503 struct spi_device *spi;
504
505 if (!spi_controller_get(ctlr))
506 return NULL;
507
508 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
509 if (!spi) {
510 spi_controller_put(ctlr);
511 return NULL;
512 }
513
514 spi->master = spi->controller = ctlr;
515 spi->dev.parent = &ctlr->dev;
516 spi->dev.bus = &spi_bus_type;
517 spi->dev.release = spidev_release;
518 spi->cs_gpio = -ENOENT;
519 spi->mode = ctlr->buswidth_override_bits;
520
521 spin_lock_init(&spi->statistics.lock);
522
523 device_initialize(&spi->dev);
524 return spi;
525}
526EXPORT_SYMBOL_GPL(spi_alloc_device);
527
528static void spi_dev_set_name(struct spi_device *spi)
529{
530 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
531
532 if (adev) {
533 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
534 return;
535 }
536
537 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
538 spi->chip_select);
539}
540
541static int spi_dev_check(struct device *dev, void *data)
542{
543 struct spi_device *spi = to_spi_device(dev);
544 struct spi_device *new_spi = data;
545
546 if (spi->controller == new_spi->controller &&
547 spi->chip_select == new_spi->chip_select)
548 return -EBUSY;
549 return 0;
550}
551
552/**
553 * spi_add_device - Add spi_device allocated with spi_alloc_device
554 * @spi: spi_device to register
555 *
556 * Companion function to spi_alloc_device. Devices allocated with
557 * spi_alloc_device can be added onto the spi bus with this function.
558 *
559 * Return: 0 on success; negative errno on failure
560 */
561int spi_add_device(struct spi_device *spi)
562{
563 struct spi_controller *ctlr = spi->controller;
564 struct device *dev = ctlr->dev.parent;
565 int status;
566
567 /* Chipselects are numbered 0..max; validate. */
568 if (spi->chip_select >= ctlr->num_chipselect) {
569 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
570 ctlr->num_chipselect);
571 return -EINVAL;
572 }
573
574 /* Set the bus ID string */
575 spi_dev_set_name(spi);
576
577 /* We need to make sure there's no other device with this
578 * chipselect **BEFORE** we call setup(), else we'll trash
579 * its configuration. Lock against concurrent add() calls.
580 */
581 mutex_lock(&spi_add_lock);
582
583 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
584 if (status) {
585 dev_err(dev, "chipselect %d already in use\n",
586 spi->chip_select);
587 goto done;
588 }
589
590 /* Controller may unregister concurrently */
591 if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
592 !device_is_registered(&ctlr->dev)) {
593 status = -ENODEV;
594 goto done;
595 }
596
597 /* Descriptors take precedence */
598 if (ctlr->cs_gpiods)
599 spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
600 else if (ctlr->cs_gpios)
601 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
602
603 /* Drivers may modify this initial i/o setup, but will
604 * normally rely on the device being setup. Devices
605 * using SPI_CS_HIGH can't coexist well otherwise...
606 */
607 status = spi_setup(spi);
608 if (status < 0) {
609 dev_err(dev, "can't setup %s, status %d\n",
610 dev_name(&spi->dev), status);
611 goto done;
612 }
613
614 /* Device may be bound to an active driver when this returns */
615 status = device_add(&spi->dev);
616 if (status < 0)
617 dev_err(dev, "can't add %s, status %d\n",
618 dev_name(&spi->dev), status);
619 else
620 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
621
622done:
623 mutex_unlock(&spi_add_lock);
624 return status;
625}
626EXPORT_SYMBOL_GPL(spi_add_device);
627
628/**
629 * spi_new_device - instantiate one new SPI device
630 * @ctlr: Controller to which device is connected
631 * @chip: Describes the SPI device
632 * Context: can sleep
633 *
634 * On typical mainboards, this is purely internal; and it's not needed
635 * after board init creates the hard-wired devices. Some development
636 * platforms may not be able to use spi_register_board_info though, and
637 * this is exported so that for example a USB or parport based adapter
638 * driver could add devices (which it would learn about out-of-band).
639 *
640 * Return: the new device, or NULL.
641 */
642struct spi_device *spi_new_device(struct spi_controller *ctlr,
643 struct spi_board_info *chip)
644{
645 struct spi_device *proxy;
646 int status;
647
648 /* NOTE: caller did any chip->bus_num checks necessary.
649 *
650 * Also, unless we change the return value convention to use
651 * error-or-pointer (not NULL-or-pointer), troubleshootability
652 * suggests syslogged diagnostics are best here (ugh).
653 */
654
655 proxy = spi_alloc_device(ctlr);
656 if (!proxy)
657 return NULL;
658
659 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
660
661 proxy->chip_select = chip->chip_select;
662 proxy->max_speed_hz = chip->max_speed_hz;
663 proxy->mode = chip->mode;
664 proxy->irq = chip->irq;
665 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
666 proxy->dev.platform_data = (void *) chip->platform_data;
667 proxy->controller_data = chip->controller_data;
668 proxy->controller_state = NULL;
669
670 if (chip->properties) {
671 status = device_add_properties(&proxy->dev, chip->properties);
672 if (status) {
673 dev_err(&ctlr->dev,
674 "failed to add properties to '%s': %d\n",
675 chip->modalias, status);
676 goto err_dev_put;
677 }
678 }
679
680 status = spi_add_device(proxy);
681 if (status < 0)
682 goto err_remove_props;
683
684 return proxy;
685
686err_remove_props:
687 if (chip->properties)
688 device_remove_properties(&proxy->dev);
689err_dev_put:
690 spi_dev_put(proxy);
691 return NULL;
692}
693EXPORT_SYMBOL_GPL(spi_new_device);
694
695/**
696 * spi_unregister_device - unregister a single SPI device
697 * @spi: spi_device to unregister
698 *
699 * Start making the passed SPI device vanish. Normally this would be handled
700 * by spi_unregister_controller().
701 */
702void spi_unregister_device(struct spi_device *spi)
703{
704 if (!spi)
705 return;
706
707 if (spi->dev.of_node) {
708 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
709 of_node_put(spi->dev.of_node);
710 }
711 if (ACPI_COMPANION(&spi->dev))
712 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
713 device_unregister(&spi->dev);
714}
715EXPORT_SYMBOL_GPL(spi_unregister_device);
716
717static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
718 struct spi_board_info *bi)
719{
720 struct spi_device *dev;
721
722 if (ctlr->bus_num != bi->bus_num)
723 return;
724
725 dev = spi_new_device(ctlr, bi);
726 if (!dev)
727 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
728 bi->modalias);
729}
730
731/**
732 * spi_register_board_info - register SPI devices for a given board
733 * @info: array of chip descriptors
734 * @n: how many descriptors are provided
735 * Context: can sleep
736 *
737 * Board-specific early init code calls this (probably during arch_initcall)
738 * with segments of the SPI device table. Any device nodes are created later,
739 * after the relevant parent SPI controller (bus_num) is defined. We keep
740 * this table of devices forever, so that reloading a controller driver will
741 * not make Linux forget about these hard-wired devices.
742 *
743 * Other code can also call this, e.g. a particular add-on board might provide
744 * SPI devices through its expansion connector, so code initializing that board
745 * would naturally declare its SPI devices.
746 *
747 * The board info passed can safely be __initdata ... but be careful of
748 * any embedded pointers (platform_data, etc), they're copied as-is.
749 * Device properties are deep-copied though.
750 *
751 * Return: zero on success, else a negative error code.
752 */
753int spi_register_board_info(struct spi_board_info const *info, unsigned n)
754{
755 struct boardinfo *bi;
756 int i;
757
758 if (!n)
759 return 0;
760
761 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
762 if (!bi)
763 return -ENOMEM;
764
765 for (i = 0; i < n; i++, bi++, info++) {
766 struct spi_controller *ctlr;
767
768 memcpy(&bi->board_info, info, sizeof(*info));
769 if (info->properties) {
770 bi->board_info.properties =
771 property_entries_dup(info->properties);
772 if (IS_ERR(bi->board_info.properties))
773 return PTR_ERR(bi->board_info.properties);
774 }
775
776 mutex_lock(&board_lock);
777 list_add_tail(&bi->list, &board_list);
778 list_for_each_entry(ctlr, &spi_controller_list, list)
779 spi_match_controller_to_boardinfo(ctlr,
780 &bi->board_info);
781 mutex_unlock(&board_lock);
782 }
783
784 return 0;
785}
786
787/*-------------------------------------------------------------------------*/
788
789static void spi_set_cs(struct spi_device *spi, bool enable)
790{
791 bool enable1 = enable;
792
793 /*
794 * Avoid calling into the driver (or doing delays) if the chip select
795 * isn't actually changing from the last time this was called.
796 */
797 if ((spi->controller->last_cs_enable == enable) &&
798 (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
799 return;
800
801 spi->controller->last_cs_enable = enable;
802 spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
803
804 if (!spi->controller->set_cs_timing) {
805 if (enable1)
806 spi_delay_exec(&spi->controller->cs_setup, NULL);
807 else
808 spi_delay_exec(&spi->controller->cs_hold, NULL);
809 }
810
811 if (spi->mode & SPI_CS_HIGH)
812 enable = !enable;
813
814 if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
815 /*
816 * Honour the SPI_NO_CS flag and invert the enable line, as
817 * active low is default for SPI. Execution paths that handle
818 * polarity inversion in gpiolib (such as device tree) will
819 * enforce active high using the SPI_CS_HIGH resulting in a
820 * double inversion through the code above.
821 */
822 if (!(spi->mode & SPI_NO_CS)) {
823 if (spi->cs_gpiod)
824 gpiod_set_value_cansleep(spi->cs_gpiod,
825 !enable);
826 else
827 gpio_set_value_cansleep(spi->cs_gpio, !enable);
828 }
829 /* Some SPI masters need both GPIO CS & slave_select */
830 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
831 spi->controller->set_cs)
832 spi->controller->set_cs(spi, !enable);
833 } else if (spi->controller->set_cs) {
834 spi->controller->set_cs(spi, !enable);
835 }
836
837 if (!spi->controller->set_cs_timing) {
838 if (!enable1)
839 spi_delay_exec(&spi->controller->cs_inactive, NULL);
840 }
841}
842
843#ifdef CONFIG_HAS_DMA
844int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
845 struct sg_table *sgt, void *buf, size_t len,
846 enum dma_data_direction dir)
847{
848 const bool vmalloced_buf = is_vmalloc_addr(buf);
849 unsigned int max_seg_size = dma_get_max_seg_size(dev);
850#ifdef CONFIG_HIGHMEM
851 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
852 (unsigned long)buf < (PKMAP_BASE +
853 (LAST_PKMAP * PAGE_SIZE)));
854#else
855 const bool kmap_buf = false;
856#endif
857 int desc_len;
858 int sgs;
859 struct page *vm_page;
860 struct scatterlist *sg;
861 void *sg_buf;
862 size_t min;
863 int i, ret;
864
865 if (vmalloced_buf || kmap_buf) {
866 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
867 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
868 } else if (virt_addr_valid(buf)) {
869 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
870 sgs = DIV_ROUND_UP(len, desc_len);
871 } else {
872 return -EINVAL;
873 }
874
875 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
876 if (ret != 0)
877 return ret;
878
879 sg = &sgt->sgl[0];
880 for (i = 0; i < sgs; i++) {
881
882 if (vmalloced_buf || kmap_buf) {
883 /*
884 * Next scatterlist entry size is the minimum between
885 * the desc_len and the remaining buffer length that
886 * fits in a page.
887 */
888 min = min_t(size_t, desc_len,
889 min_t(size_t, len,
890 PAGE_SIZE - offset_in_page(buf)));
891 if (vmalloced_buf)
892 vm_page = vmalloc_to_page(buf);
893 else
894 vm_page = kmap_to_page(buf);
895 if (!vm_page) {
896 sg_free_table(sgt);
897 return -ENOMEM;
898 }
899 sg_set_page(sg, vm_page,
900 min, offset_in_page(buf));
901 } else {
902 min = min_t(size_t, len, desc_len);
903 sg_buf = buf;
904 sg_set_buf(sg, sg_buf, min);
905 }
906
907 buf += min;
908 len -= min;
909 sg = sg_next(sg);
910 }
911
912 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
913 if (!ret)
914 ret = -ENOMEM;
915 if (ret < 0) {
916 sg_free_table(sgt);
917 return ret;
918 }
919
920 sgt->nents = ret;
921
922 return 0;
923}
924
925void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
926 struct sg_table *sgt, enum dma_data_direction dir)
927{
928 if (sgt->orig_nents) {
929 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
930 sg_free_table(sgt);
931 }
932}
933
934static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
935{
936 struct device *tx_dev, *rx_dev;
937 struct spi_transfer *xfer;
938 int ret;
939
940 if (!ctlr->can_dma)
941 return 0;
942
943 if (ctlr->dma_tx)
944 tx_dev = ctlr->dma_tx->device->dev;
945 else
946 tx_dev = ctlr->dev.parent;
947
948 if (ctlr->dma_rx)
949 rx_dev = ctlr->dma_rx->device->dev;
950 else
951 rx_dev = ctlr->dev.parent;
952
953 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
954 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
955 continue;
956
957 if (xfer->tx_buf != NULL) {
958 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
959 (void *)xfer->tx_buf, xfer->len,
960 DMA_TO_DEVICE);
961 if (ret != 0)
962 return ret;
963 }
964
965 if (xfer->rx_buf != NULL) {
966 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
967 xfer->rx_buf, xfer->len,
968 DMA_FROM_DEVICE);
969 if (ret != 0) {
970 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
971 DMA_TO_DEVICE);
972 return ret;
973 }
974 }
975 }
976
977 ctlr->cur_msg_mapped = true;
978
979 return 0;
980}
981
982static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
983{
984 struct spi_transfer *xfer;
985 struct device *tx_dev, *rx_dev;
986
987 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
988 return 0;
989
990 if (ctlr->dma_tx)
991 tx_dev = ctlr->dma_tx->device->dev;
992 else
993 tx_dev = ctlr->dev.parent;
994
995 if (ctlr->dma_rx)
996 rx_dev = ctlr->dma_rx->device->dev;
997 else
998 rx_dev = ctlr->dev.parent;
999
1000 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1001 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
1002 continue;
1003
1004 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
1005 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
1006 }
1007
1008 ctlr->cur_msg_mapped = false;
1009
1010 return 0;
1011}
1012#else /* !CONFIG_HAS_DMA */
1013static inline int __spi_map_msg(struct spi_controller *ctlr,
1014 struct spi_message *msg)
1015{
1016 return 0;
1017}
1018
1019static inline int __spi_unmap_msg(struct spi_controller *ctlr,
1020 struct spi_message *msg)
1021{
1022 return 0;
1023}
1024#endif /* !CONFIG_HAS_DMA */
1025
1026static inline int spi_unmap_msg(struct spi_controller *ctlr,
1027 struct spi_message *msg)
1028{
1029 struct spi_transfer *xfer;
1030
1031 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1032 /*
1033 * Restore the original value of tx_buf or rx_buf if they are
1034 * NULL.
1035 */
1036 if (xfer->tx_buf == ctlr->dummy_tx)
1037 xfer->tx_buf = NULL;
1038 if (xfer->rx_buf == ctlr->dummy_rx)
1039 xfer->rx_buf = NULL;
1040 }
1041
1042 return __spi_unmap_msg(ctlr, msg);
1043}
1044
1045static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
1046{
1047 struct spi_transfer *xfer;
1048 void *tmp;
1049 unsigned int max_tx, max_rx;
1050
1051 if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))
1052 && !(msg->spi->mode & SPI_3WIRE)) {
1053 max_tx = 0;
1054 max_rx = 0;
1055
1056 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1057 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
1058 !xfer->tx_buf)
1059 max_tx = max(xfer->len, max_tx);
1060 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
1061 !xfer->rx_buf)
1062 max_rx = max(xfer->len, max_rx);
1063 }
1064
1065 if (max_tx) {
1066 tmp = krealloc(ctlr->dummy_tx, max_tx,
1067 GFP_KERNEL | GFP_DMA);
1068 if (!tmp)
1069 return -ENOMEM;
1070 ctlr->dummy_tx = tmp;
1071 memset(tmp, 0, max_tx);
1072 }
1073
1074 if (max_rx) {
1075 tmp = krealloc(ctlr->dummy_rx, max_rx,
1076 GFP_KERNEL | GFP_DMA);
1077 if (!tmp)
1078 return -ENOMEM;
1079 ctlr->dummy_rx = tmp;
1080 }
1081
1082 if (max_tx || max_rx) {
1083 list_for_each_entry(xfer, &msg->transfers,
1084 transfer_list) {
1085 if (!xfer->len)
1086 continue;
1087 if (!xfer->tx_buf)
1088 xfer->tx_buf = ctlr->dummy_tx;
1089 if (!xfer->rx_buf)
1090 xfer->rx_buf = ctlr->dummy_rx;
1091 }
1092 }
1093 }
1094
1095 return __spi_map_msg(ctlr, msg);
1096}
1097
1098static int spi_transfer_wait(struct spi_controller *ctlr,
1099 struct spi_message *msg,
1100 struct spi_transfer *xfer)
1101{
1102 struct spi_statistics *statm = &ctlr->statistics;
1103 struct spi_statistics *stats = &msg->spi->statistics;
1104 unsigned long long ms;
1105
1106 if (spi_controller_is_slave(ctlr)) {
1107 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1108 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1109 return -EINTR;
1110 }
1111 } else {
1112 ms = 8LL * 1000LL * xfer->len;
1113 do_div(ms, xfer->speed_hz);
1114 ms += ms + 200; /* some tolerance */
1115
1116 if (ms > UINT_MAX)
1117 ms = UINT_MAX;
1118
1119 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1120 msecs_to_jiffies(ms));
1121
1122 if (ms == 0) {
1123 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1124 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1125 dev_err(&msg->spi->dev,
1126 "SPI transfer timed out\n");
1127 return -ETIMEDOUT;
1128 }
1129 }
1130
1131 return 0;
1132}
1133
1134static void _spi_transfer_delay_ns(u32 ns)
1135{
1136 if (!ns)
1137 return;
1138 if (ns <= 1000) {
1139 ndelay(ns);
1140 } else {
1141 u32 us = DIV_ROUND_UP(ns, 1000);
1142
1143 if (us <= 10)
1144 udelay(us);
1145 else
1146 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1147 }
1148}
1149
1150int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
1151{
1152 u32 delay = _delay->value;
1153 u32 unit = _delay->unit;
1154 u32 hz;
1155
1156 if (!delay)
1157 return 0;
1158
1159 switch (unit) {
1160 case SPI_DELAY_UNIT_USECS:
1161 delay *= 1000;
1162 break;
1163 case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
1164 break;
1165 case SPI_DELAY_UNIT_SCK:
1166 /* clock cycles need to be obtained from spi_transfer */
1167 if (!xfer)
1168 return -EINVAL;
1169 /* if there is no effective speed know, then approximate
1170 * by underestimating with half the requested hz
1171 */
1172 hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
1173 if (!hz)
1174 return -EINVAL;
1175 delay *= DIV_ROUND_UP(1000000000, hz);
1176 break;
1177 default:
1178 return -EINVAL;
1179 }
1180
1181 return delay;
1182}
1183EXPORT_SYMBOL_GPL(spi_delay_to_ns);
1184
1185int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
1186{
1187 int delay;
1188
1189 might_sleep();
1190
1191 if (!_delay)
1192 return -EINVAL;
1193
1194 delay = spi_delay_to_ns(_delay, xfer);
1195 if (delay < 0)
1196 return delay;
1197
1198 _spi_transfer_delay_ns(delay);
1199
1200 return 0;
1201}
1202EXPORT_SYMBOL_GPL(spi_delay_exec);
1203
1204static void _spi_transfer_cs_change_delay(struct spi_message *msg,
1205 struct spi_transfer *xfer)
1206{
1207 u32 delay = xfer->cs_change_delay.value;
1208 u32 unit = xfer->cs_change_delay.unit;
1209 int ret;
1210
1211 /* return early on "fast" mode - for everything but USECS */
1212 if (!delay) {
1213 if (unit == SPI_DELAY_UNIT_USECS)
1214 _spi_transfer_delay_ns(10000);
1215 return;
1216 }
1217
1218 ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
1219 if (ret) {
1220 dev_err_once(&msg->spi->dev,
1221 "Use of unsupported delay unit %i, using default of 10us\n",
1222 unit);
1223 _spi_transfer_delay_ns(10000);
1224 }
1225}
1226
1227/*
1228 * spi_transfer_one_message - Default implementation of transfer_one_message()
1229 *
1230 * This is a standard implementation of transfer_one_message() for
1231 * drivers which implement a transfer_one() operation. It provides
1232 * standard handling of delays and chip select management.
1233 */
1234static int spi_transfer_one_message(struct spi_controller *ctlr,
1235 struct spi_message *msg)
1236{
1237 struct spi_transfer *xfer;
1238 bool keep_cs = false;
1239 int ret = 0;
1240 struct spi_statistics *statm = &ctlr->statistics;
1241 struct spi_statistics *stats = &msg->spi->statistics;
1242
1243 spi_set_cs(msg->spi, true);
1244
1245 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1246 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1247
1248 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1249 trace_spi_transfer_start(msg, xfer);
1250
1251 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1252 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
1253
1254 if (!ctlr->ptp_sts_supported) {
1255 xfer->ptp_sts_word_pre = 0;
1256 ptp_read_system_prets(xfer->ptp_sts);
1257 }
1258
1259 if (xfer->tx_buf || xfer->rx_buf) {
1260 reinit_completion(&ctlr->xfer_completion);
1261
1262fallback_pio:
1263 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
1264 if (ret < 0) {
1265 if (ctlr->cur_msg_mapped &&
1266 (xfer->error & SPI_TRANS_FAIL_NO_START)) {
1267 __spi_unmap_msg(ctlr, msg);
1268 ctlr->fallback = true;
1269 xfer->error &= ~SPI_TRANS_FAIL_NO_START;
1270 goto fallback_pio;
1271 }
1272
1273 SPI_STATISTICS_INCREMENT_FIELD(statm,
1274 errors);
1275 SPI_STATISTICS_INCREMENT_FIELD(stats,
1276 errors);
1277 dev_err(&msg->spi->dev,
1278 "SPI transfer failed: %d\n", ret);
1279 goto out;
1280 }
1281
1282 if (ret > 0) {
1283 ret = spi_transfer_wait(ctlr, msg, xfer);
1284 if (ret < 0)
1285 msg->status = ret;
1286 }
1287 } else {
1288 if (xfer->len)
1289 dev_err(&msg->spi->dev,
1290 "Bufferless transfer has length %u\n",
1291 xfer->len);
1292 }
1293
1294 if (!ctlr->ptp_sts_supported) {
1295 ptp_read_system_postts(xfer->ptp_sts);
1296 xfer->ptp_sts_word_post = xfer->len;
1297 }
1298
1299 trace_spi_transfer_stop(msg, xfer);
1300
1301 if (msg->status != -EINPROGRESS)
1302 goto out;
1303
1304 spi_transfer_delay_exec(xfer);
1305
1306 if (xfer->cs_change) {
1307 if (list_is_last(&xfer->transfer_list,
1308 &msg->transfers)) {
1309 keep_cs = true;
1310 } else {
1311 spi_set_cs(msg->spi, false);
1312 _spi_transfer_cs_change_delay(msg, xfer);
1313 spi_set_cs(msg->spi, true);
1314 }
1315 }
1316
1317 msg->actual_length += xfer->len;
1318 }
1319
1320out:
1321 if (ret != 0 || !keep_cs)
1322 spi_set_cs(msg->spi, false);
1323
1324 if (msg->status == -EINPROGRESS)
1325 msg->status = ret;
1326
1327 if (msg->status && ctlr->handle_err)
1328 ctlr->handle_err(ctlr, msg);
1329
1330 spi_finalize_current_message(ctlr);
1331
1332 return ret;
1333}
1334
1335/**
1336 * spi_finalize_current_transfer - report completion of a transfer
1337 * @ctlr: the controller reporting completion
1338 *
1339 * Called by SPI drivers using the core transfer_one_message()
1340 * implementation to notify it that the current interrupt driven
1341 * transfer has finished and the next one may be scheduled.
1342 */
1343void spi_finalize_current_transfer(struct spi_controller *ctlr)
1344{
1345 complete(&ctlr->xfer_completion);
1346}
1347EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1348
1349static void spi_idle_runtime_pm(struct spi_controller *ctlr)
1350{
1351 if (ctlr->auto_runtime_pm) {
1352 pm_runtime_mark_last_busy(ctlr->dev.parent);
1353 pm_runtime_put_autosuspend(ctlr->dev.parent);
1354 }
1355}
1356
1357/**
1358 * __spi_pump_messages - function which processes spi message queue
1359 * @ctlr: controller to process queue for
1360 * @in_kthread: true if we are in the context of the message pump thread
1361 *
1362 * This function checks if there is any spi message in the queue that
1363 * needs processing and if so call out to the driver to initialize hardware
1364 * and transfer each message.
1365 *
1366 * Note that it is called both from the kthread itself and also from
1367 * inside spi_sync(); the queue extraction handling at the top of the
1368 * function should deal with this safely.
1369 */
1370static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
1371{
1372 struct spi_transfer *xfer;
1373 struct spi_message *msg;
1374 bool was_busy = false;
1375 unsigned long flags;
1376 int ret;
1377
1378 /* Lock queue */
1379 spin_lock_irqsave(&ctlr->queue_lock, flags);
1380
1381 /* Make sure we are not already running a message */
1382 if (ctlr->cur_msg) {
1383 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1384 return;
1385 }
1386
1387 /* If another context is idling the device then defer */
1388 if (ctlr->idling) {
1389 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1390 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1391 return;
1392 }
1393
1394 /* Check if the queue is idle */
1395 if (list_empty(&ctlr->queue) || !ctlr->running) {
1396 if (!ctlr->busy) {
1397 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1398 return;
1399 }
1400
1401 /* Defer any non-atomic teardown to the thread */
1402 if (!in_kthread) {
1403 if (!ctlr->dummy_rx && !ctlr->dummy_tx &&
1404 !ctlr->unprepare_transfer_hardware) {
1405 spi_idle_runtime_pm(ctlr);
1406 ctlr->busy = false;
1407 trace_spi_controller_idle(ctlr);
1408 } else {
1409 kthread_queue_work(ctlr->kworker,
1410 &ctlr->pump_messages);
1411 }
1412 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1413 return;
1414 }
1415
1416 ctlr->busy = false;
1417 ctlr->idling = true;
1418 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1419
1420 kfree(ctlr->dummy_rx);
1421 ctlr->dummy_rx = NULL;
1422 kfree(ctlr->dummy_tx);
1423 ctlr->dummy_tx = NULL;
1424 if (ctlr->unprepare_transfer_hardware &&
1425 ctlr->unprepare_transfer_hardware(ctlr))
1426 dev_err(&ctlr->dev,
1427 "failed to unprepare transfer hardware\n");
1428 spi_idle_runtime_pm(ctlr);
1429 trace_spi_controller_idle(ctlr);
1430
1431 spin_lock_irqsave(&ctlr->queue_lock, flags);
1432 ctlr->idling = false;
1433 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1434 return;
1435 }
1436
1437 /* Extract head of queue */
1438 msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
1439 ctlr->cur_msg = msg;
1440
1441 list_del_init(&msg->queue);
1442 if (ctlr->busy)
1443 was_busy = true;
1444 else
1445 ctlr->busy = true;
1446 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1447
1448 mutex_lock(&ctlr->io_mutex);
1449
1450 if (!was_busy && ctlr->auto_runtime_pm) {
1451 ret = pm_runtime_get_sync(ctlr->dev.parent);
1452 if (ret < 0) {
1453 pm_runtime_put_noidle(ctlr->dev.parent);
1454 dev_err(&ctlr->dev, "Failed to power device: %d\n",
1455 ret);
1456 mutex_unlock(&ctlr->io_mutex);
1457 return;
1458 }
1459 }
1460
1461 if (!was_busy)
1462 trace_spi_controller_busy(ctlr);
1463
1464 if (!was_busy && ctlr->prepare_transfer_hardware) {
1465 ret = ctlr->prepare_transfer_hardware(ctlr);
1466 if (ret) {
1467 dev_err(&ctlr->dev,
1468 "failed to prepare transfer hardware: %d\n",
1469 ret);
1470
1471 if (ctlr->auto_runtime_pm)
1472 pm_runtime_put(ctlr->dev.parent);
1473
1474 msg->status = ret;
1475 spi_finalize_current_message(ctlr);
1476
1477 mutex_unlock(&ctlr->io_mutex);
1478 return;
1479 }
1480 }
1481
1482 trace_spi_message_start(msg);
1483
1484 if (ctlr->prepare_message) {
1485 ret = ctlr->prepare_message(ctlr, msg);
1486 if (ret) {
1487 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1488 ret);
1489 msg->status = ret;
1490 spi_finalize_current_message(ctlr);
1491 goto out;
1492 }
1493 ctlr->cur_msg_prepared = true;
1494 }
1495
1496 ret = spi_map_msg(ctlr, msg);
1497 if (ret) {
1498 msg->status = ret;
1499 spi_finalize_current_message(ctlr);
1500 goto out;
1501 }
1502
1503 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1504 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1505 xfer->ptp_sts_word_pre = 0;
1506 ptp_read_system_prets(xfer->ptp_sts);
1507 }
1508 }
1509
1510 ret = ctlr->transfer_one_message(ctlr, msg);
1511 if (ret) {
1512 dev_err(&ctlr->dev,
1513 "failed to transfer one message from queue\n");
1514 goto out;
1515 }
1516
1517out:
1518 mutex_unlock(&ctlr->io_mutex);
1519
1520 /* Prod the scheduler in case transfer_one() was busy waiting */
1521 if (!ret)
1522 cond_resched();
1523}
1524
1525/**
1526 * spi_pump_messages - kthread work function which processes spi message queue
1527 * @work: pointer to kthread work struct contained in the controller struct
1528 */
1529static void spi_pump_messages(struct kthread_work *work)
1530{
1531 struct spi_controller *ctlr =
1532 container_of(work, struct spi_controller, pump_messages);
1533
1534 __spi_pump_messages(ctlr, true);
1535}
1536
1537/**
1538 * spi_take_timestamp_pre - helper for drivers to collect the beginning of the
1539 * TX timestamp for the requested byte from the SPI
1540 * transfer. The frequency with which this function
1541 * must be called (once per word, once for the whole
1542 * transfer, once per batch of words etc) is arbitrary
1543 * as long as the @tx buffer offset is greater than or
1544 * equal to the requested byte at the time of the
1545 * call. The timestamp is only taken once, at the
1546 * first such call. It is assumed that the driver
1547 * advances its @tx buffer pointer monotonically.
1548 * @ctlr: Pointer to the spi_controller structure of the driver
1549 * @xfer: Pointer to the transfer being timestamped
1550 * @progress: How many words (not bytes) have been transferred so far
1551 * @irqs_off: If true, will disable IRQs and preemption for the duration of the
1552 * transfer, for less jitter in time measurement. Only compatible
1553 * with PIO drivers. If true, must follow up with
1554 * spi_take_timestamp_post or otherwise system will crash.
1555 * WARNING: for fully predictable results, the CPU frequency must
1556 * also be under control (governor).
1557 */
1558void spi_take_timestamp_pre(struct spi_controller *ctlr,
1559 struct spi_transfer *xfer,
1560 size_t progress, bool irqs_off)
1561{
1562 if (!xfer->ptp_sts)
1563 return;
1564
1565 if (xfer->timestamped)
1566 return;
1567
1568 if (progress > xfer->ptp_sts_word_pre)
1569 return;
1570
1571 /* Capture the resolution of the timestamp */
1572 xfer->ptp_sts_word_pre = progress;
1573
1574 if (irqs_off) {
1575 local_irq_save(ctlr->irq_flags);
1576 preempt_disable();
1577 }
1578
1579 ptp_read_system_prets(xfer->ptp_sts);
1580}
1581EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
1582
1583/**
1584 * spi_take_timestamp_post - helper for drivers to collect the end of the
1585 * TX timestamp for the requested byte from the SPI
1586 * transfer. Can be called with an arbitrary
1587 * frequency: only the first call where @tx exceeds
1588 * or is equal to the requested word will be
1589 * timestamped.
1590 * @ctlr: Pointer to the spi_controller structure of the driver
1591 * @xfer: Pointer to the transfer being timestamped
1592 * @progress: How many words (not bytes) have been transferred so far
1593 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
1594 */
1595void spi_take_timestamp_post(struct spi_controller *ctlr,
1596 struct spi_transfer *xfer,
1597 size_t progress, bool irqs_off)
1598{
1599 if (!xfer->ptp_sts)
1600 return;
1601
1602 if (xfer->timestamped)
1603 return;
1604
1605 if (progress < xfer->ptp_sts_word_post)
1606 return;
1607
1608 ptp_read_system_postts(xfer->ptp_sts);
1609
1610 if (irqs_off) {
1611 local_irq_restore(ctlr->irq_flags);
1612 preempt_enable();
1613 }
1614
1615 /* Capture the resolution of the timestamp */
1616 xfer->ptp_sts_word_post = progress;
1617
1618 xfer->timestamped = true;
1619}
1620EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
1621
1622/**
1623 * spi_set_thread_rt - set the controller to pump at realtime priority
1624 * @ctlr: controller to boost priority of
1625 *
1626 * This can be called because the controller requested realtime priority
1627 * (by setting the ->rt value before calling spi_register_controller()) or
1628 * because a device on the bus said that its transfers needed realtime
1629 * priority.
1630 *
1631 * NOTE: at the moment if any device on a bus says it needs realtime then
1632 * the thread will be at realtime priority for all transfers on that
1633 * controller. If this eventually becomes a problem we may see if we can
1634 * find a way to boost the priority only temporarily during relevant
1635 * transfers.
1636 */
1637static void spi_set_thread_rt(struct spi_controller *ctlr)
1638{
1639 dev_info(&ctlr->dev,
1640 "will run message pump with realtime priority\n");
1641 sched_set_fifo(ctlr->kworker->task);
1642}
1643
1644static int spi_init_queue(struct spi_controller *ctlr)
1645{
1646 ctlr->running = false;
1647 ctlr->busy = false;
1648
1649 ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));
1650 if (IS_ERR(ctlr->kworker)) {
1651 dev_err(&ctlr->dev, "failed to create message pump kworker\n");
1652 return PTR_ERR(ctlr->kworker);
1653 }
1654
1655 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
1656
1657 /*
1658 * Controller config will indicate if this controller should run the
1659 * message pump with high (realtime) priority to reduce the transfer
1660 * latency on the bus by minimising the delay between a transfer
1661 * request and the scheduling of the message pump thread. Without this
1662 * setting the message pump thread will remain at default priority.
1663 */
1664 if (ctlr->rt)
1665 spi_set_thread_rt(ctlr);
1666
1667 return 0;
1668}
1669
1670/**
1671 * spi_get_next_queued_message() - called by driver to check for queued
1672 * messages
1673 * @ctlr: the controller to check for queued messages
1674 *
1675 * If there are more messages in the queue, the next message is returned from
1676 * this call.
1677 *
1678 * Return: the next message in the queue, else NULL if the queue is empty.
1679 */
1680struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
1681{
1682 struct spi_message *next;
1683 unsigned long flags;
1684
1685 /* get a pointer to the next message, if any */
1686 spin_lock_irqsave(&ctlr->queue_lock, flags);
1687 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1688 queue);
1689 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1690
1691 return next;
1692}
1693EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1694
1695/**
1696 * spi_finalize_current_message() - the current message is complete
1697 * @ctlr: the controller to return the message to
1698 *
1699 * Called by the driver to notify the core that the message in the front of the
1700 * queue is complete and can be removed from the queue.
1701 */
1702void spi_finalize_current_message(struct spi_controller *ctlr)
1703{
1704 struct spi_transfer *xfer;
1705 struct spi_message *mesg;
1706 unsigned long flags;
1707 int ret;
1708
1709 spin_lock_irqsave(&ctlr->queue_lock, flags);
1710 mesg = ctlr->cur_msg;
1711 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1712
1713 if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
1714 list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
1715 ptp_read_system_postts(xfer->ptp_sts);
1716 xfer->ptp_sts_word_post = xfer->len;
1717 }
1718 }
1719
1720 if (unlikely(ctlr->ptp_sts_supported))
1721 list_for_each_entry(xfer, &mesg->transfers, transfer_list)
1722 WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);
1723
1724 spi_unmap_msg(ctlr, mesg);
1725
1726 /* In the prepare_messages callback the spi bus has the opportunity to
1727 * split a transfer to smaller chunks.
1728 * Release splited transfers here since spi_map_msg is done on the
1729 * splited transfers.
1730 */
1731 spi_res_release(ctlr, mesg);
1732
1733 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1734 ret = ctlr->unprepare_message(ctlr, mesg);
1735 if (ret) {
1736 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1737 ret);
1738 }
1739 }
1740
1741 spin_lock_irqsave(&ctlr->queue_lock, flags);
1742 ctlr->cur_msg = NULL;
1743 ctlr->cur_msg_prepared = false;
1744 ctlr->fallback = false;
1745 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1746 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1747
1748 trace_spi_message_done(mesg);
1749
1750 mesg->state = NULL;
1751 if (mesg->complete)
1752 mesg->complete(mesg->context);
1753}
1754EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1755
1756static int spi_start_queue(struct spi_controller *ctlr)
1757{
1758 unsigned long flags;
1759
1760 spin_lock_irqsave(&ctlr->queue_lock, flags);
1761
1762 if (ctlr->running || ctlr->busy) {
1763 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1764 return -EBUSY;
1765 }
1766
1767 ctlr->running = true;
1768 ctlr->cur_msg = NULL;
1769 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1770
1771 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1772
1773 return 0;
1774}
1775
1776static int spi_stop_queue(struct spi_controller *ctlr)
1777{
1778 unsigned long flags;
1779 unsigned limit = 500;
1780 int ret = 0;
1781
1782 spin_lock_irqsave(&ctlr->queue_lock, flags);
1783
1784 /*
1785 * This is a bit lame, but is optimized for the common execution path.
1786 * A wait_queue on the ctlr->busy could be used, but then the common
1787 * execution path (pump_messages) would be required to call wake_up or
1788 * friends on every SPI message. Do this instead.
1789 */
1790 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1791 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1792 usleep_range(10000, 11000);
1793 spin_lock_irqsave(&ctlr->queue_lock, flags);
1794 }
1795
1796 if (!list_empty(&ctlr->queue) || ctlr->busy)
1797 ret = -EBUSY;
1798 else
1799 ctlr->running = false;
1800
1801 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1802
1803 if (ret) {
1804 dev_warn(&ctlr->dev, "could not stop message queue\n");
1805 return ret;
1806 }
1807 return ret;
1808}
1809
1810static int spi_destroy_queue(struct spi_controller *ctlr)
1811{
1812 int ret;
1813
1814 ret = spi_stop_queue(ctlr);
1815
1816 /*
1817 * kthread_flush_worker will block until all work is done.
1818 * If the reason that stop_queue timed out is that the work will never
1819 * finish, then it does no good to call flush/stop thread, so
1820 * return anyway.
1821 */
1822 if (ret) {
1823 dev_err(&ctlr->dev, "problem destroying queue\n");
1824 return ret;
1825 }
1826
1827 kthread_destroy_worker(ctlr->kworker);
1828
1829 return 0;
1830}
1831
1832static int __spi_queued_transfer(struct spi_device *spi,
1833 struct spi_message *msg,
1834 bool need_pump)
1835{
1836 struct spi_controller *ctlr = spi->controller;
1837 unsigned long flags;
1838
1839 spin_lock_irqsave(&ctlr->queue_lock, flags);
1840
1841 if (!ctlr->running) {
1842 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1843 return -ESHUTDOWN;
1844 }
1845 msg->actual_length = 0;
1846 msg->status = -EINPROGRESS;
1847
1848 list_add_tail(&msg->queue, &ctlr->queue);
1849 if (!ctlr->busy && need_pump)
1850 kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
1851
1852 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1853 return 0;
1854}
1855
1856/**
1857 * spi_queued_transfer - transfer function for queued transfers
1858 * @spi: spi device which is requesting transfer
1859 * @msg: spi message which is to handled is queued to driver queue
1860 *
1861 * Return: zero on success, else a negative error code.
1862 */
1863static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1864{
1865 return __spi_queued_transfer(spi, msg, true);
1866}
1867
1868static int spi_controller_initialize_queue(struct spi_controller *ctlr)
1869{
1870 int ret;
1871
1872 ctlr->transfer = spi_queued_transfer;
1873 if (!ctlr->transfer_one_message)
1874 ctlr->transfer_one_message = spi_transfer_one_message;
1875
1876 /* Initialize and start queue */
1877 ret = spi_init_queue(ctlr);
1878 if (ret) {
1879 dev_err(&ctlr->dev, "problem initializing queue\n");
1880 goto err_init_queue;
1881 }
1882 ctlr->queued = true;
1883 ret = spi_start_queue(ctlr);
1884 if (ret) {
1885 dev_err(&ctlr->dev, "problem starting queue\n");
1886 goto err_start_queue;
1887 }
1888
1889 return 0;
1890
1891err_start_queue:
1892 spi_destroy_queue(ctlr);
1893err_init_queue:
1894 return ret;
1895}
1896
1897/**
1898 * spi_flush_queue - Send all pending messages in the queue from the callers'
1899 * context
1900 * @ctlr: controller to process queue for
1901 *
1902 * This should be used when one wants to ensure all pending messages have been
1903 * sent before doing something. Is used by the spi-mem code to make sure SPI
1904 * memory operations do not preempt regular SPI transfers that have been queued
1905 * before the spi-mem operation.
1906 */
1907void spi_flush_queue(struct spi_controller *ctlr)
1908{
1909 if (ctlr->transfer == spi_queued_transfer)
1910 __spi_pump_messages(ctlr, false);
1911}
1912
1913/*-------------------------------------------------------------------------*/
1914
1915#if defined(CONFIG_OF)
1916static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
1917 struct device_node *nc)
1918{
1919 u32 value;
1920 int rc;
1921
1922 /* Mode (clock phase/polarity/etc.) */
1923 if (of_property_read_bool(nc, "spi-cpha"))
1924 spi->mode |= SPI_CPHA;
1925 if (of_property_read_bool(nc, "spi-cpol"))
1926 spi->mode |= SPI_CPOL;
1927 if (of_property_read_bool(nc, "spi-3wire"))
1928 spi->mode |= SPI_3WIRE;
1929 if (of_property_read_bool(nc, "spi-lsb-first"))
1930 spi->mode |= SPI_LSB_FIRST;
1931 if (of_property_read_bool(nc, "spi-cs-high"))
1932 spi->mode |= SPI_CS_HIGH;
1933
1934 /* Device DUAL/QUAD mode */
1935 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1936 switch (value) {
1937 case 1:
1938 break;
1939 case 2:
1940 spi->mode |= SPI_TX_DUAL;
1941 break;
1942 case 4:
1943 spi->mode |= SPI_TX_QUAD;
1944 break;
1945 case 8:
1946 spi->mode |= SPI_TX_OCTAL;
1947 break;
1948 default:
1949 dev_warn(&ctlr->dev,
1950 "spi-tx-bus-width %d not supported\n",
1951 value);
1952 break;
1953 }
1954 }
1955
1956 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1957 switch (value) {
1958 case 1:
1959 break;
1960 case 2:
1961 spi->mode |= SPI_RX_DUAL;
1962 break;
1963 case 4:
1964 spi->mode |= SPI_RX_QUAD;
1965 break;
1966 case 8:
1967 spi->mode |= SPI_RX_OCTAL;
1968 break;
1969 default:
1970 dev_warn(&ctlr->dev,
1971 "spi-rx-bus-width %d not supported\n",
1972 value);
1973 break;
1974 }
1975 }
1976
1977 if (spi_controller_is_slave(ctlr)) {
1978 if (!of_node_name_eq(nc, "slave")) {
1979 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1980 nc);
1981 return -EINVAL;
1982 }
1983 return 0;
1984 }
1985
1986 /* Device address */
1987 rc = of_property_read_u32(nc, "reg", &value);
1988 if (rc) {
1989 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1990 nc, rc);
1991 return rc;
1992 }
1993 spi->chip_select = value;
1994
1995 /*
1996 * For descriptors associated with the device, polarity inversion is
1997 * handled in the gpiolib, so all gpio chip selects are "active high"
1998 * in the logical sense, the gpiolib will invert the line if need be.
1999 */
2000 if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
2001 ctlr->cs_gpiods[spi->chip_select])
2002 spi->mode |= SPI_CS_HIGH;
2003
2004 /* Device speed */
2005 if (!of_property_read_u32(nc, "spi-max-frequency", &value))
2006 spi->max_speed_hz = value;
2007
2008 return 0;
2009}
2010
2011static struct spi_device *
2012of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
2013{
2014 struct spi_device *spi;
2015 int rc;
2016
2017 /* Alloc an spi_device */
2018 spi = spi_alloc_device(ctlr);
2019 if (!spi) {
2020 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
2021 rc = -ENOMEM;
2022 goto err_out;
2023 }
2024
2025 /* Select device driver */
2026 rc = of_modalias_node(nc, spi->modalias,
2027 sizeof(spi->modalias));
2028 if (rc < 0) {
2029 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
2030 goto err_out;
2031 }
2032
2033 rc = of_spi_parse_dt(ctlr, spi, nc);
2034 if (rc)
2035 goto err_out;
2036
2037 /* Store a pointer to the node in the device structure */
2038 of_node_get(nc);
2039 spi->dev.of_node = nc;
2040
2041 /* Register the new device */
2042 rc = spi_add_device(spi);
2043 if (rc) {
2044 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
2045 goto err_of_node_put;
2046 }
2047
2048 return spi;
2049
2050err_of_node_put:
2051 of_node_put(nc);
2052err_out:
2053 spi_dev_put(spi);
2054 return ERR_PTR(rc);
2055}
2056
2057/**
2058 * of_register_spi_devices() - Register child devices onto the SPI bus
2059 * @ctlr: Pointer to spi_controller device
2060 *
2061 * Registers an spi_device for each child node of controller node which
2062 * represents a valid SPI slave.
2063 */
2064static void of_register_spi_devices(struct spi_controller *ctlr)
2065{
2066 struct spi_device *spi;
2067 struct device_node *nc;
2068
2069 if (!ctlr->dev.of_node)
2070 return;
2071
2072 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
2073 if (of_node_test_and_set_flag(nc, OF_POPULATED))
2074 continue;
2075 spi = of_register_spi_device(ctlr, nc);
2076 if (IS_ERR(spi)) {
2077 dev_warn(&ctlr->dev,
2078 "Failed to create SPI device for %pOF\n", nc);
2079 of_node_clear_flag(nc, OF_POPULATED);
2080 }
2081 }
2082}
2083#else
2084static void of_register_spi_devices(struct spi_controller *ctlr) { }
2085#endif
2086
2087#ifdef CONFIG_ACPI
2088struct acpi_spi_lookup {
2089 struct spi_controller *ctlr;
2090 u32 max_speed_hz;
2091 u32 mode;
2092 int irq;
2093 u8 bits_per_word;
2094 u8 chip_select;
2095};
2096
2097static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
2098 struct acpi_spi_lookup *lookup)
2099{
2100 const union acpi_object *obj;
2101
2102 if (!x86_apple_machine)
2103 return;
2104
2105 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
2106 && obj->buffer.length >= 4)
2107 lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
2108
2109 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
2110 && obj->buffer.length == 8)
2111 lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
2112
2113 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
2114 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
2115 lookup->mode |= SPI_LSB_FIRST;
2116
2117 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
2118 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2119 lookup->mode |= SPI_CPOL;
2120
2121 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
2122 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
2123 lookup->mode |= SPI_CPHA;
2124}
2125
2126static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
2127{
2128 struct acpi_spi_lookup *lookup = data;
2129 struct spi_controller *ctlr = lookup->ctlr;
2130
2131 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
2132 struct acpi_resource_spi_serialbus *sb;
2133 acpi_handle parent_handle;
2134 acpi_status status;
2135
2136 sb = &ares->data.spi_serial_bus;
2137 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
2138
2139 status = acpi_get_handle(NULL,
2140 sb->resource_source.string_ptr,
2141 &parent_handle);
2142
2143 if (ACPI_FAILURE(status) ||
2144 ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
2145 return -ENODEV;
2146
2147 /*
2148 * ACPI DeviceSelection numbering is handled by the
2149 * host controller driver in Windows and can vary
2150 * from driver to driver. In Linux we always expect
2151 * 0 .. max - 1 so we need to ask the driver to
2152 * translate between the two schemes.
2153 */
2154 if (ctlr->fw_translate_cs) {
2155 int cs = ctlr->fw_translate_cs(ctlr,
2156 sb->device_selection);
2157 if (cs < 0)
2158 return cs;
2159 lookup->chip_select = cs;
2160 } else {
2161 lookup->chip_select = sb->device_selection;
2162 }
2163
2164 lookup->max_speed_hz = sb->connection_speed;
2165 lookup->bits_per_word = sb->data_bit_length;
2166
2167 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
2168 lookup->mode |= SPI_CPHA;
2169 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
2170 lookup->mode |= SPI_CPOL;
2171 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
2172 lookup->mode |= SPI_CS_HIGH;
2173 }
2174 } else if (lookup->irq < 0) {
2175 struct resource r;
2176
2177 if (acpi_dev_resource_interrupt(ares, 0, &r))
2178 lookup->irq = r.start;
2179 }
2180
2181 /* Always tell the ACPI core to skip this resource */
2182 return 1;
2183}
2184
2185static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
2186 struct acpi_device *adev)
2187{
2188 acpi_handle parent_handle = NULL;
2189 struct list_head resource_list;
2190 struct acpi_spi_lookup lookup = {};
2191 struct spi_device *spi;
2192 int ret;
2193
2194 if (acpi_bus_get_status(adev) || !adev->status.present ||
2195 acpi_device_enumerated(adev))
2196 return AE_OK;
2197
2198 lookup.ctlr = ctlr;
2199 lookup.irq = -1;
2200
2201 INIT_LIST_HEAD(&resource_list);
2202 ret = acpi_dev_get_resources(adev, &resource_list,
2203 acpi_spi_add_resource, &lookup);
2204 acpi_dev_free_resource_list(&resource_list);
2205
2206 if (ret < 0)
2207 /* found SPI in _CRS but it points to another controller */
2208 return AE_OK;
2209
2210 if (!lookup.max_speed_hz &&
2211 !ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
2212 ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
2213 /* Apple does not use _CRS but nested devices for SPI slaves */
2214 acpi_spi_parse_apple_properties(adev, &lookup);
2215 }
2216
2217 if (!lookup.max_speed_hz)
2218 return AE_OK;
2219
2220 spi = spi_alloc_device(ctlr);
2221 if (!spi) {
2222 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
2223 dev_name(&adev->dev));
2224 return AE_NO_MEMORY;
2225 }
2226
2227
2228 ACPI_COMPANION_SET(&spi->dev, adev);
2229 spi->max_speed_hz = lookup.max_speed_hz;
2230 spi->mode |= lookup.mode;
2231 spi->irq = lookup.irq;
2232 spi->bits_per_word = lookup.bits_per_word;
2233 spi->chip_select = lookup.chip_select;
2234
2235 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
2236 sizeof(spi->modalias));
2237
2238 if (spi->irq < 0)
2239 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
2240
2241 acpi_device_set_enumerated(adev);
2242
2243 adev->power.flags.ignore_parent = true;
2244 if (spi_add_device(spi)) {
2245 adev->power.flags.ignore_parent = false;
2246 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
2247 dev_name(&adev->dev));
2248 spi_dev_put(spi);
2249 }
2250
2251 return AE_OK;
2252}
2253
2254static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
2255 void *data, void **return_value)
2256{
2257 struct spi_controller *ctlr = data;
2258 struct acpi_device *adev;
2259
2260 if (acpi_bus_get_device(handle, &adev))
2261 return AE_OK;
2262
2263 return acpi_register_spi_device(ctlr, adev);
2264}
2265
2266#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
2267
2268static void acpi_register_spi_devices(struct spi_controller *ctlr)
2269{
2270 acpi_status status;
2271 acpi_handle handle;
2272
2273 handle = ACPI_HANDLE(ctlr->dev.parent);
2274 if (!handle)
2275 return;
2276
2277 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2278 SPI_ACPI_ENUMERATE_MAX_DEPTH,
2279 acpi_spi_add_device, NULL, ctlr, NULL);
2280 if (ACPI_FAILURE(status))
2281 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
2282}
2283#else
2284static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
2285#endif /* CONFIG_ACPI */
2286
2287static void spi_controller_release(struct device *dev)
2288{
2289 struct spi_controller *ctlr;
2290
2291 ctlr = container_of(dev, struct spi_controller, dev);
2292 kfree(ctlr);
2293}
2294
2295static struct class spi_master_class = {
2296 .name = "spi_master",
2297 .owner = THIS_MODULE,
2298 .dev_release = spi_controller_release,
2299 .dev_groups = spi_master_groups,
2300};
2301
2302#ifdef CONFIG_SPI_SLAVE
2303/**
2304 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
2305 * controller
2306 * @spi: device used for the current transfer
2307 */
2308int spi_slave_abort(struct spi_device *spi)
2309{
2310 struct spi_controller *ctlr = spi->controller;
2311
2312 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
2313 return ctlr->slave_abort(ctlr);
2314
2315 return -ENOTSUPP;
2316}
2317EXPORT_SYMBOL_GPL(spi_slave_abort);
2318
2319static int match_true(struct device *dev, void *data)
2320{
2321 return 1;
2322}
2323
2324static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
2325 char *buf)
2326{
2327 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2328 dev);
2329 struct device *child;
2330
2331 child = device_find_child(&ctlr->dev, NULL, match_true);
2332 return sprintf(buf, "%s\n",
2333 child ? to_spi_device(child)->modalias : NULL);
2334}
2335
2336static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
2337 const char *buf, size_t count)
2338{
2339 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
2340 dev);
2341 struct spi_device *spi;
2342 struct device *child;
2343 char name[32];
2344 int rc;
2345
2346 rc = sscanf(buf, "%31s", name);
2347 if (rc != 1 || !name[0])
2348 return -EINVAL;
2349
2350 child = device_find_child(&ctlr->dev, NULL, match_true);
2351 if (child) {
2352 /* Remove registered slave */
2353 device_unregister(child);
2354 put_device(child);
2355 }
2356
2357 if (strcmp(name, "(null)")) {
2358 /* Register new slave */
2359 spi = spi_alloc_device(ctlr);
2360 if (!spi)
2361 return -ENOMEM;
2362
2363 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2364
2365 rc = spi_add_device(spi);
2366 if (rc) {
2367 spi_dev_put(spi);
2368 return rc;
2369 }
2370 }
2371
2372 return count;
2373}
2374
2375static DEVICE_ATTR_RW(slave);
2376
2377static struct attribute *spi_slave_attrs[] = {
2378 &dev_attr_slave.attr,
2379 NULL,
2380};
2381
2382static const struct attribute_group spi_slave_group = {
2383 .attrs = spi_slave_attrs,
2384};
2385
2386static const struct attribute_group *spi_slave_groups[] = {
2387 &spi_controller_statistics_group,
2388 &spi_slave_group,
2389 NULL,
2390};
2391
2392static struct class spi_slave_class = {
2393 .name = "spi_slave",
2394 .owner = THIS_MODULE,
2395 .dev_release = spi_controller_release,
2396 .dev_groups = spi_slave_groups,
2397};
2398#else
2399extern struct class spi_slave_class; /* dummy */
2400#endif
2401
2402/**
2403 * __spi_alloc_controller - allocate an SPI master or slave controller
2404 * @dev: the controller, possibly using the platform_bus
2405 * @size: how much zeroed driver-private data to allocate; the pointer to this
2406 * memory is in the driver_data field of the returned device, accessible
2407 * with spi_controller_get_devdata(); the memory is cacheline aligned;
2408 * drivers granting DMA access to portions of their private data need to
2409 * round up @size using ALIGN(size, dma_get_cache_alignment()).
2410 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2411 * slave (true) controller
2412 * Context: can sleep
2413 *
2414 * This call is used only by SPI controller drivers, which are the
2415 * only ones directly touching chip registers. It's how they allocate
2416 * an spi_controller structure, prior to calling spi_register_controller().
2417 *
2418 * This must be called from context that can sleep.
2419 *
2420 * The caller is responsible for assigning the bus number and initializing the
2421 * controller's methods before calling spi_register_controller(); and (after
2422 * errors adding the device) calling spi_controller_put() to prevent a memory
2423 * leak.
2424 *
2425 * Return: the SPI controller structure on success, else NULL.
2426 */
2427struct spi_controller *__spi_alloc_controller(struct device *dev,
2428 unsigned int size, bool slave)
2429{
2430 struct spi_controller *ctlr;
2431 size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
2432
2433 if (!dev)
2434 return NULL;
2435
2436 ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
2437 if (!ctlr)
2438 return NULL;
2439
2440 device_initialize(&ctlr->dev);
2441 ctlr->bus_num = -1;
2442 ctlr->num_chipselect = 1;
2443 ctlr->slave = slave;
2444 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
2445 ctlr->dev.class = &spi_slave_class;
2446 else
2447 ctlr->dev.class = &spi_master_class;
2448 ctlr->dev.parent = dev;
2449 pm_suspend_ignore_children(&ctlr->dev, true);
2450 spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
2451
2452 return ctlr;
2453}
2454EXPORT_SYMBOL_GPL(__spi_alloc_controller);
2455
2456#ifdef CONFIG_OF
2457static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2458{
2459 int nb, i, *cs;
2460 struct device_node *np = ctlr->dev.of_node;
2461
2462 if (!np)
2463 return 0;
2464
2465 nb = of_gpio_named_count(np, "cs-gpios");
2466 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2467
2468 /* Return error only for an incorrectly formed cs-gpios property */
2469 if (nb == 0 || nb == -ENOENT)
2470 return 0;
2471 else if (nb < 0)
2472 return nb;
2473
2474 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
2475 GFP_KERNEL);
2476 ctlr->cs_gpios = cs;
2477
2478 if (!ctlr->cs_gpios)
2479 return -ENOMEM;
2480
2481 for (i = 0; i < ctlr->num_chipselect; i++)
2482 cs[i] = -ENOENT;
2483
2484 for (i = 0; i < nb; i++)
2485 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2486
2487 return 0;
2488}
2489#else
2490static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
2491{
2492 return 0;
2493}
2494#endif
2495
2496/**
2497 * spi_get_gpio_descs() - grab chip select GPIOs for the master
2498 * @ctlr: The SPI master to grab GPIO descriptors for
2499 */
2500static int spi_get_gpio_descs(struct spi_controller *ctlr)
2501{
2502 int nb, i;
2503 struct gpio_desc **cs;
2504 struct device *dev = &ctlr->dev;
2505 unsigned long native_cs_mask = 0;
2506 unsigned int num_cs_gpios = 0;
2507
2508 nb = gpiod_count(dev, "cs");
2509 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
2510
2511 /* No GPIOs at all is fine, else return the error */
2512 if (nb == 0 || nb == -ENOENT)
2513 return 0;
2514 else if (nb < 0)
2515 return nb;
2516
2517 cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
2518 GFP_KERNEL);
2519 if (!cs)
2520 return -ENOMEM;
2521 ctlr->cs_gpiods = cs;
2522
2523 for (i = 0; i < nb; i++) {
2524 /*
2525 * Most chipselects are active low, the inverted
2526 * semantics are handled by special quirks in gpiolib,
2527 * so initializing them GPIOD_OUT_LOW here means
2528 * "unasserted", in most cases this will drive the physical
2529 * line high.
2530 */
2531 cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
2532 GPIOD_OUT_LOW);
2533 if (IS_ERR(cs[i]))
2534 return PTR_ERR(cs[i]);
2535
2536 if (cs[i]) {
2537 /*
2538 * If we find a CS GPIO, name it after the device and
2539 * chip select line.
2540 */
2541 char *gpioname;
2542
2543 gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
2544 dev_name(dev), i);
2545 if (!gpioname)
2546 return -ENOMEM;
2547 gpiod_set_consumer_name(cs[i], gpioname);
2548 num_cs_gpios++;
2549 continue;
2550 }
2551
2552 if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {
2553 dev_err(dev, "Invalid native chip select %d\n", i);
2554 return -EINVAL;
2555 }
2556 native_cs_mask |= BIT(i);
2557 }
2558
2559 ctlr->unused_native_cs = ffz(native_cs_mask);
2560 if (num_cs_gpios && ctlr->max_native_cs &&
2561 ctlr->unused_native_cs >= ctlr->max_native_cs) {
2562 dev_err(dev, "No unused native chip select available\n");
2563 return -EINVAL;
2564 }
2565
2566 return 0;
2567}
2568
2569static int spi_controller_check_ops(struct spi_controller *ctlr)
2570{
2571 /*
2572 * The controller may implement only the high-level SPI-memory like
2573 * operations if it does not support regular SPI transfers, and this is
2574 * valid use case.
2575 * If ->mem_ops is NULL, we request that at least one of the
2576 * ->transfer_xxx() method be implemented.
2577 */
2578 if (ctlr->mem_ops) {
2579 if (!ctlr->mem_ops->exec_op)
2580 return -EINVAL;
2581 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2582 !ctlr->transfer_one_message) {
2583 return -EINVAL;
2584 }
2585
2586 return 0;
2587}
2588
2589/**
2590 * spi_register_controller - register SPI master or slave controller
2591 * @ctlr: initialized master, originally from spi_alloc_master() or
2592 * spi_alloc_slave()
2593 * Context: can sleep
2594 *
2595 * SPI controllers connect to their drivers using some non-SPI bus,
2596 * such as the platform bus. The final stage of probe() in that code
2597 * includes calling spi_register_controller() to hook up to this SPI bus glue.
2598 *
2599 * SPI controllers use board specific (often SOC specific) bus numbers,
2600 * and board-specific addressing for SPI devices combines those numbers
2601 * with chip select numbers. Since SPI does not directly support dynamic
2602 * device identification, boards need configuration tables telling which
2603 * chip is at which address.
2604 *
2605 * This must be called from context that can sleep. It returns zero on
2606 * success, else a negative error code (dropping the controller's refcount).
2607 * After a successful return, the caller is responsible for calling
2608 * spi_unregister_controller().
2609 *
2610 * Return: zero on success, else a negative error code.
2611 */
2612int spi_register_controller(struct spi_controller *ctlr)
2613{
2614 struct device *dev = ctlr->dev.parent;
2615 struct boardinfo *bi;
2616 int status;
2617 int id, first_dynamic;
2618
2619 if (!dev)
2620 return -ENODEV;
2621
2622 /*
2623 * Make sure all necessary hooks are implemented before registering
2624 * the SPI controller.
2625 */
2626 status = spi_controller_check_ops(ctlr);
2627 if (status)
2628 return status;
2629
2630 if (ctlr->bus_num >= 0) {
2631 /* devices with a fixed bus num must check-in with the num */
2632 mutex_lock(&board_lock);
2633 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2634 ctlr->bus_num + 1, GFP_KERNEL);
2635 mutex_unlock(&board_lock);
2636 if (WARN(id < 0, "couldn't get idr"))
2637 return id == -ENOSPC ? -EBUSY : id;
2638 ctlr->bus_num = id;
2639 } else if (ctlr->dev.of_node) {
2640 /* allocate dynamic bus number using Linux idr */
2641 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2642 if (id >= 0) {
2643 ctlr->bus_num = id;
2644 mutex_lock(&board_lock);
2645 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2646 ctlr->bus_num + 1, GFP_KERNEL);
2647 mutex_unlock(&board_lock);
2648 if (WARN(id < 0, "couldn't get idr"))
2649 return id == -ENOSPC ? -EBUSY : id;
2650 }
2651 }
2652 if (ctlr->bus_num < 0) {
2653 first_dynamic = of_alias_get_highest_id("spi");
2654 if (first_dynamic < 0)
2655 first_dynamic = 0;
2656 else
2657 first_dynamic++;
2658
2659 mutex_lock(&board_lock);
2660 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2661 0, GFP_KERNEL);
2662 mutex_unlock(&board_lock);
2663 if (WARN(id < 0, "couldn't get idr"))
2664 return id;
2665 ctlr->bus_num = id;
2666 }
2667 INIT_LIST_HEAD(&ctlr->queue);
2668 spin_lock_init(&ctlr->queue_lock);
2669 spin_lock_init(&ctlr->bus_lock_spinlock);
2670 mutex_init(&ctlr->bus_lock_mutex);
2671 mutex_init(&ctlr->io_mutex);
2672 ctlr->bus_lock_flag = 0;
2673 init_completion(&ctlr->xfer_completion);
2674 if (!ctlr->max_dma_len)
2675 ctlr->max_dma_len = INT_MAX;
2676
2677 /* register the device, then userspace will see it.
2678 * registration fails if the bus ID is in use.
2679 */
2680 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2681
2682 if (!spi_controller_is_slave(ctlr)) {
2683 if (ctlr->use_gpio_descriptors) {
2684 status = spi_get_gpio_descs(ctlr);
2685 if (status)
2686 goto free_bus_id;
2687 /*
2688 * A controller using GPIO descriptors always
2689 * supports SPI_CS_HIGH if need be.
2690 */
2691 ctlr->mode_bits |= SPI_CS_HIGH;
2692 } else {
2693 /* Legacy code path for GPIOs from DT */
2694 status = of_spi_get_gpio_numbers(ctlr);
2695 if (status)
2696 goto free_bus_id;
2697 }
2698 }
2699
2700 /*
2701 * Even if it's just one always-selected device, there must
2702 * be at least one chipselect.
2703 */
2704 if (!ctlr->num_chipselect) {
2705 status = -EINVAL;
2706 goto free_bus_id;
2707 }
2708
2709 status = device_add(&ctlr->dev);
2710 if (status < 0)
2711 goto free_bus_id;
2712 dev_dbg(dev, "registered %s %s\n",
2713 spi_controller_is_slave(ctlr) ? "slave" : "master",
2714 dev_name(&ctlr->dev));
2715
2716 /*
2717 * If we're using a queued driver, start the queue. Note that we don't
2718 * need the queueing logic if the driver is only supporting high-level
2719 * memory operations.
2720 */
2721 if (ctlr->transfer) {
2722 dev_info(dev, "controller is unqueued, this is deprecated\n");
2723 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
2724 status = spi_controller_initialize_queue(ctlr);
2725 if (status) {
2726 device_del(&ctlr->dev);
2727 goto free_bus_id;
2728 }
2729 }
2730 /* add statistics */
2731 spin_lock_init(&ctlr->statistics.lock);
2732
2733 mutex_lock(&board_lock);
2734 list_add_tail(&ctlr->list, &spi_controller_list);
2735 list_for_each_entry(bi, &board_list, list)
2736 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2737 mutex_unlock(&board_lock);
2738
2739 /* Register devices from the device tree and ACPI */
2740 of_register_spi_devices(ctlr);
2741 acpi_register_spi_devices(ctlr);
2742 return status;
2743
2744free_bus_id:
2745 mutex_lock(&board_lock);
2746 idr_remove(&spi_master_idr, ctlr->bus_num);
2747 mutex_unlock(&board_lock);
2748 return status;
2749}
2750EXPORT_SYMBOL_GPL(spi_register_controller);
2751
2752static void devm_spi_unregister(struct device *dev, void *res)
2753{
2754 spi_unregister_controller(*(struct spi_controller **)res);
2755}
2756
2757/**
2758 * devm_spi_register_controller - register managed SPI master or slave
2759 * controller
2760 * @dev: device managing SPI controller
2761 * @ctlr: initialized controller, originally from spi_alloc_master() or
2762 * spi_alloc_slave()
2763 * Context: can sleep
2764 *
2765 * Register a SPI device as with spi_register_controller() which will
2766 * automatically be unregistered and freed.
2767 *
2768 * Return: zero on success, else a negative error code.
2769 */
2770int devm_spi_register_controller(struct device *dev,
2771 struct spi_controller *ctlr)
2772{
2773 struct spi_controller **ptr;
2774 int ret;
2775
2776 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2777 if (!ptr)
2778 return -ENOMEM;
2779
2780 ret = spi_register_controller(ctlr);
2781 if (!ret) {
2782 *ptr = ctlr;
2783 devres_add(dev, ptr);
2784 } else {
2785 devres_free(ptr);
2786 }
2787
2788 return ret;
2789}
2790EXPORT_SYMBOL_GPL(devm_spi_register_controller);
2791
2792static int __unregister(struct device *dev, void *null)
2793{
2794 spi_unregister_device(to_spi_device(dev));
2795 return 0;
2796}
2797
2798/**
2799 * spi_unregister_controller - unregister SPI master or slave controller
2800 * @ctlr: the controller being unregistered
2801 * Context: can sleep
2802 *
2803 * This call is used only by SPI controller drivers, which are the
2804 * only ones directly touching chip registers.
2805 *
2806 * This must be called from context that can sleep.
2807 *
2808 * Note that this function also drops a reference to the controller.
2809 */
2810void spi_unregister_controller(struct spi_controller *ctlr)
2811{
2812 struct spi_controller *found;
2813 int id = ctlr->bus_num;
2814
2815 /* Prevent addition of new devices, unregister existing ones */
2816 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2817 mutex_lock(&spi_add_lock);
2818
2819 device_for_each_child(&ctlr->dev, NULL, __unregister);
2820
2821 /* First make sure that this controller was ever added */
2822 mutex_lock(&board_lock);
2823 found = idr_find(&spi_master_idr, id);
2824 mutex_unlock(&board_lock);
2825 if (ctlr->queued) {
2826 if (spi_destroy_queue(ctlr))
2827 dev_err(&ctlr->dev, "queue remove failed\n");
2828 }
2829 mutex_lock(&board_lock);
2830 list_del(&ctlr->list);
2831 mutex_unlock(&board_lock);
2832
2833 device_unregister(&ctlr->dev);
2834 /* free bus id */
2835 mutex_lock(&board_lock);
2836 if (found == ctlr)
2837 idr_remove(&spi_master_idr, id);
2838 mutex_unlock(&board_lock);
2839
2840 if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
2841 mutex_unlock(&spi_add_lock);
2842}
2843EXPORT_SYMBOL_GPL(spi_unregister_controller);
2844
2845int spi_controller_suspend(struct spi_controller *ctlr)
2846{
2847 int ret;
2848
2849 /* Basically no-ops for non-queued controllers */
2850 if (!ctlr->queued)
2851 return 0;
2852
2853 ret = spi_stop_queue(ctlr);
2854 if (ret)
2855 dev_err(&ctlr->dev, "queue stop failed\n");
2856
2857 return ret;
2858}
2859EXPORT_SYMBOL_GPL(spi_controller_suspend);
2860
2861int spi_controller_resume(struct spi_controller *ctlr)
2862{
2863 int ret;
2864
2865 if (!ctlr->queued)
2866 return 0;
2867
2868 ret = spi_start_queue(ctlr);
2869 if (ret)
2870 dev_err(&ctlr->dev, "queue restart failed\n");
2871
2872 return ret;
2873}
2874EXPORT_SYMBOL_GPL(spi_controller_resume);
2875
2876static int __spi_controller_match(struct device *dev, const void *data)
2877{
2878 struct spi_controller *ctlr;
2879 const u16 *bus_num = data;
2880
2881 ctlr = container_of(dev, struct spi_controller, dev);
2882 return ctlr->bus_num == *bus_num;
2883}
2884
2885/**
2886 * spi_busnum_to_master - look up master associated with bus_num
2887 * @bus_num: the master's bus number
2888 * Context: can sleep
2889 *
2890 * This call may be used with devices that are registered after
2891 * arch init time. It returns a refcounted pointer to the relevant
2892 * spi_controller (which the caller must release), or NULL if there is
2893 * no such master registered.
2894 *
2895 * Return: the SPI master structure on success, else NULL.
2896 */
2897struct spi_controller *spi_busnum_to_master(u16 bus_num)
2898{
2899 struct device *dev;
2900 struct spi_controller *ctlr = NULL;
2901
2902 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2903 __spi_controller_match);
2904 if (dev)
2905 ctlr = container_of(dev, struct spi_controller, dev);
2906 /* reference got in class_find_device */
2907 return ctlr;
2908}
2909EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2910
2911/*-------------------------------------------------------------------------*/
2912
2913/* Core methods for SPI resource management */
2914
2915/**
2916 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2917 * during the processing of a spi_message while using
2918 * spi_transfer_one
2919 * @spi: the spi device for which we allocate memory
2920 * @release: the release code to execute for this resource
2921 * @size: size to alloc and return
2922 * @gfp: GFP allocation flags
2923 *
2924 * Return: the pointer to the allocated data
2925 *
2926 * This may get enhanced in the future to allocate from a memory pool
2927 * of the @spi_device or @spi_controller to avoid repeated allocations.
2928 */
2929void *spi_res_alloc(struct spi_device *spi,
2930 spi_res_release_t release,
2931 size_t size, gfp_t gfp)
2932{
2933 struct spi_res *sres;
2934
2935 sres = kzalloc(sizeof(*sres) + size, gfp);
2936 if (!sres)
2937 return NULL;
2938
2939 INIT_LIST_HEAD(&sres->entry);
2940 sres->release = release;
2941
2942 return sres->data;
2943}
2944EXPORT_SYMBOL_GPL(spi_res_alloc);
2945
2946/**
2947 * spi_res_free - free an spi resource
2948 * @res: pointer to the custom data of a resource
2949 *
2950 */
2951void spi_res_free(void *res)
2952{
2953 struct spi_res *sres = container_of(res, struct spi_res, data);
2954
2955 if (!res)
2956 return;
2957
2958 WARN_ON(!list_empty(&sres->entry));
2959 kfree(sres);
2960}
2961EXPORT_SYMBOL_GPL(spi_res_free);
2962
2963/**
2964 * spi_res_add - add a spi_res to the spi_message
2965 * @message: the spi message
2966 * @res: the spi_resource
2967 */
2968void spi_res_add(struct spi_message *message, void *res)
2969{
2970 struct spi_res *sres = container_of(res, struct spi_res, data);
2971
2972 WARN_ON(!list_empty(&sres->entry));
2973 list_add_tail(&sres->entry, &message->resources);
2974}
2975EXPORT_SYMBOL_GPL(spi_res_add);
2976
2977/**
2978 * spi_res_release - release all spi resources for this message
2979 * @ctlr: the @spi_controller
2980 * @message: the @spi_message
2981 */
2982void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
2983{
2984 struct spi_res *res, *tmp;
2985
2986 list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
2987 if (res->release)
2988 res->release(ctlr, message, res->data);
2989
2990 list_del(&res->entry);
2991
2992 kfree(res);
2993 }
2994}
2995EXPORT_SYMBOL_GPL(spi_res_release);
2996
2997/*-------------------------------------------------------------------------*/
2998
2999/* Core methods for spi_message alterations */
3000
3001static void __spi_replace_transfers_release(struct spi_controller *ctlr,
3002 struct spi_message *msg,
3003 void *res)
3004{
3005 struct spi_replaced_transfers *rxfer = res;
3006 size_t i;
3007
3008 /* call extra callback if requested */
3009 if (rxfer->release)
3010 rxfer->release(ctlr, msg, res);
3011
3012 /* insert replaced transfers back into the message */
3013 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
3014
3015 /* remove the formerly inserted entries */
3016 for (i = 0; i < rxfer->inserted; i++)
3017 list_del(&rxfer->inserted_transfers[i].transfer_list);
3018}
3019
3020/**
3021 * spi_replace_transfers - replace transfers with several transfers
3022 * and register change with spi_message.resources
3023 * @msg: the spi_message we work upon
3024 * @xfer_first: the first spi_transfer we want to replace
3025 * @remove: number of transfers to remove
3026 * @insert: the number of transfers we want to insert instead
3027 * @release: extra release code necessary in some circumstances
3028 * @extradatasize: extra data to allocate (with alignment guarantees
3029 * of struct @spi_transfer)
3030 * @gfp: gfp flags
3031 *
3032 * Returns: pointer to @spi_replaced_transfers,
3033 * PTR_ERR(...) in case of errors.
3034 */
3035struct spi_replaced_transfers *spi_replace_transfers(
3036 struct spi_message *msg,
3037 struct spi_transfer *xfer_first,
3038 size_t remove,
3039 size_t insert,
3040 spi_replaced_release_t release,
3041 size_t extradatasize,
3042 gfp_t gfp)
3043{
3044 struct spi_replaced_transfers *rxfer;
3045 struct spi_transfer *xfer;
3046 size_t i;
3047
3048 /* allocate the structure using spi_res */
3049 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
3050 struct_size(rxfer, inserted_transfers, insert)
3051 + extradatasize,
3052 gfp);
3053 if (!rxfer)
3054 return ERR_PTR(-ENOMEM);
3055
3056 /* the release code to invoke before running the generic release */
3057 rxfer->release = release;
3058
3059 /* assign extradata */
3060 if (extradatasize)
3061 rxfer->extradata =
3062 &rxfer->inserted_transfers[insert];
3063
3064 /* init the replaced_transfers list */
3065 INIT_LIST_HEAD(&rxfer->replaced_transfers);
3066
3067 /* assign the list_entry after which we should reinsert
3068 * the @replaced_transfers - it may be spi_message.messages!
3069 */
3070 rxfer->replaced_after = xfer_first->transfer_list.prev;
3071
3072 /* remove the requested number of transfers */
3073 for (i = 0; i < remove; i++) {
3074 /* if the entry after replaced_after it is msg->transfers
3075 * then we have been requested to remove more transfers
3076 * than are in the list
3077 */
3078 if (rxfer->replaced_after->next == &msg->transfers) {
3079 dev_err(&msg->spi->dev,
3080 "requested to remove more spi_transfers than are available\n");
3081 /* insert replaced transfers back into the message */
3082 list_splice(&rxfer->replaced_transfers,
3083 rxfer->replaced_after);
3084
3085 /* free the spi_replace_transfer structure */
3086 spi_res_free(rxfer);
3087
3088 /* and return with an error */
3089 return ERR_PTR(-EINVAL);
3090 }
3091
3092 /* remove the entry after replaced_after from list of
3093 * transfers and add it to list of replaced_transfers
3094 */
3095 list_move_tail(rxfer->replaced_after->next,
3096 &rxfer->replaced_transfers);
3097 }
3098
3099 /* create copy of the given xfer with identical settings
3100 * based on the first transfer to get removed
3101 */
3102 for (i = 0; i < insert; i++) {
3103 /* we need to run in reverse order */
3104 xfer = &rxfer->inserted_transfers[insert - 1 - i];
3105
3106 /* copy all spi_transfer data */
3107 memcpy(xfer, xfer_first, sizeof(*xfer));
3108
3109 /* add to list */
3110 list_add(&xfer->transfer_list, rxfer->replaced_after);
3111
3112 /* clear cs_change and delay for all but the last */
3113 if (i) {
3114 xfer->cs_change = false;
3115 xfer->delay_usecs = 0;
3116 xfer->delay.value = 0;
3117 }
3118 }
3119
3120 /* set up inserted */
3121 rxfer->inserted = insert;
3122
3123 /* and register it with spi_res/spi_message */
3124 spi_res_add(msg, rxfer);
3125
3126 return rxfer;
3127}
3128EXPORT_SYMBOL_GPL(spi_replace_transfers);
3129
3130static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
3131 struct spi_message *msg,
3132 struct spi_transfer **xferp,
3133 size_t maxsize,
3134 gfp_t gfp)
3135{
3136 struct spi_transfer *xfer = *xferp, *xfers;
3137 struct spi_replaced_transfers *srt;
3138 size_t offset;
3139 size_t count, i;
3140
3141 /* calculate how many we have to replace */
3142 count = DIV_ROUND_UP(xfer->len, maxsize);
3143
3144 /* create replacement */
3145 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
3146 if (IS_ERR(srt))
3147 return PTR_ERR(srt);
3148 xfers = srt->inserted_transfers;
3149
3150 /* now handle each of those newly inserted spi_transfers
3151 * note that the replacements spi_transfers all are preset
3152 * to the same values as *xferp, so tx_buf, rx_buf and len
3153 * are all identical (as well as most others)
3154 * so we just have to fix up len and the pointers.
3155 *
3156 * this also includes support for the depreciated
3157 * spi_message.is_dma_mapped interface
3158 */
3159
3160 /* the first transfer just needs the length modified, so we
3161 * run it outside the loop
3162 */
3163 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
3164
3165 /* all the others need rx_buf/tx_buf also set */
3166 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
3167 /* update rx_buf, tx_buf and dma */
3168 if (xfers[i].rx_buf)
3169 xfers[i].rx_buf += offset;
3170 if (xfers[i].rx_dma)
3171 xfers[i].rx_dma += offset;
3172 if (xfers[i].tx_buf)
3173 xfers[i].tx_buf += offset;
3174 if (xfers[i].tx_dma)
3175 xfers[i].tx_dma += offset;
3176
3177 /* update length */
3178 xfers[i].len = min(maxsize, xfers[i].len - offset);
3179 }
3180
3181 /* we set up xferp to the last entry we have inserted,
3182 * so that we skip those already split transfers
3183 */
3184 *xferp = &xfers[count - 1];
3185
3186 /* increment statistics counters */
3187 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3188 transfers_split_maxsize);
3189 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
3190 transfers_split_maxsize);
3191
3192 return 0;
3193}
3194
3195/**
3196 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
3197 * when an individual transfer exceeds a
3198 * certain size
3199 * @ctlr: the @spi_controller for this transfer
3200 * @msg: the @spi_message to transform
3201 * @maxsize: the maximum when to apply this
3202 * @gfp: GFP allocation flags
3203 *
3204 * Return: status of transformation
3205 */
3206int spi_split_transfers_maxsize(struct spi_controller *ctlr,
3207 struct spi_message *msg,
3208 size_t maxsize,
3209 gfp_t gfp)
3210{
3211 struct spi_transfer *xfer;
3212 int ret;
3213
3214 /* iterate over the transfer_list,
3215 * but note that xfer is advanced to the last transfer inserted
3216 * to avoid checking sizes again unnecessarily (also xfer does
3217 * potentiall belong to a different list by the time the
3218 * replacement has happened
3219 */
3220 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
3221 if (xfer->len > maxsize) {
3222 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
3223 maxsize, gfp);
3224 if (ret)
3225 return ret;
3226 }
3227 }
3228
3229 return 0;
3230}
3231EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
3232
3233/*-------------------------------------------------------------------------*/
3234
3235/* Core methods for SPI controller protocol drivers. Some of the
3236 * other core methods are currently defined as inline functions.
3237 */
3238
3239static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
3240 u8 bits_per_word)
3241{
3242 if (ctlr->bits_per_word_mask) {
3243 /* Only 32 bits fit in the mask */
3244 if (bits_per_word > 32)
3245 return -EINVAL;
3246 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
3247 return -EINVAL;
3248 }
3249
3250 return 0;
3251}
3252
3253/**
3254 * spi_setup - setup SPI mode and clock rate
3255 * @spi: the device whose settings are being modified
3256 * Context: can sleep, and no requests are queued to the device
3257 *
3258 * SPI protocol drivers may need to update the transfer mode if the
3259 * device doesn't work with its default. They may likewise need
3260 * to update clock rates or word sizes from initial values. This function
3261 * changes those settings, and must be called from a context that can sleep.
3262 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
3263 * effect the next time the device is selected and data is transferred to
3264 * or from it. When this function returns, the spi device is deselected.
3265 *
3266 * Note that this call will fail if the protocol driver specifies an option
3267 * that the underlying controller or its driver does not support. For
3268 * example, not all hardware supports wire transfers using nine bit words,
3269 * LSB-first wire encoding, or active-high chipselects.
3270 *
3271 * Return: zero on success, else a negative error code.
3272 */
3273int spi_setup(struct spi_device *spi)
3274{
3275 unsigned bad_bits, ugly_bits;
3276 int status;
3277
3278 /* check mode to prevent that DUAL and QUAD set at the same time
3279 */
3280 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
3281 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
3282 dev_err(&spi->dev,
3283 "setup: can not select dual and quad at the same time\n");
3284 return -EINVAL;
3285 }
3286 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
3287 */
3288 if ((spi->mode & SPI_3WIRE) && (spi->mode &
3289 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3290 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
3291 return -EINVAL;
3292 /* help drivers fail *cleanly* when they need options
3293 * that aren't supported with their current controller
3294 * SPI_CS_WORD has a fallback software implementation,
3295 * so it is ignored here.
3296 */
3297 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
3298 /* nothing prevents from working with active-high CS in case if it
3299 * is driven by GPIO.
3300 */
3301 if (gpio_is_valid(spi->cs_gpio))
3302 bad_bits &= ~SPI_CS_HIGH;
3303 ugly_bits = bad_bits &
3304 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
3305 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
3306 if (ugly_bits) {
3307 dev_warn(&spi->dev,
3308 "setup: ignoring unsupported mode bits %x\n",
3309 ugly_bits);
3310 spi->mode &= ~ugly_bits;
3311 bad_bits &= ~ugly_bits;
3312 }
3313 if (bad_bits) {
3314 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
3315 bad_bits);
3316 return -EINVAL;
3317 }
3318
3319 if (!spi->bits_per_word)
3320 spi->bits_per_word = 8;
3321
3322 status = __spi_validate_bits_per_word(spi->controller,
3323 spi->bits_per_word);
3324 if (status)
3325 return status;
3326
3327 if (!spi->max_speed_hz)
3328 spi->max_speed_hz = spi->controller->max_speed_hz;
3329
3330 if (spi->controller->setup)
3331 status = spi->controller->setup(spi);
3332
3333 if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
3334 status = pm_runtime_get_sync(spi->controller->dev.parent);
3335 if (status < 0) {
3336 pm_runtime_put_noidle(spi->controller->dev.parent);
3337 dev_err(&spi->controller->dev, "Failed to power device: %d\n",
3338 status);
3339 return status;
3340 }
3341
3342 /*
3343 * We do not want to return positive value from pm_runtime_get,
3344 * there are many instances of devices calling spi_setup() and
3345 * checking for a non-zero return value instead of a negative
3346 * return value.
3347 */
3348 status = 0;
3349
3350 spi_set_cs(spi, false);
3351 pm_runtime_mark_last_busy(spi->controller->dev.parent);
3352 pm_runtime_put_autosuspend(spi->controller->dev.parent);
3353 } else {
3354 spi_set_cs(spi, false);
3355 }
3356
3357 if (spi->rt && !spi->controller->rt) {
3358 spi->controller->rt = true;
3359 spi_set_thread_rt(spi->controller);
3360 }
3361
3362 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
3363 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
3364 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
3365 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
3366 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
3367 (spi->mode & SPI_LOOP) ? "loopback, " : "",
3368 spi->bits_per_word, spi->max_speed_hz,
3369 status);
3370
3371 return status;
3372}
3373EXPORT_SYMBOL_GPL(spi_setup);
3374
3375/**
3376 * spi_set_cs_timing - configure CS setup, hold, and inactive delays
3377 * @spi: the device that requires specific CS timing configuration
3378 * @setup: CS setup time specified via @spi_delay
3379 * @hold: CS hold time specified via @spi_delay
3380 * @inactive: CS inactive delay between transfers specified via @spi_delay
3381 *
3382 * Return: zero on success, else a negative error code.
3383 */
3384int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
3385 struct spi_delay *hold, struct spi_delay *inactive)
3386{
3387 size_t len;
3388
3389 if (spi->controller->set_cs_timing)
3390 return spi->controller->set_cs_timing(spi, setup, hold,
3391 inactive);
3392
3393 if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
3394 (hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
3395 (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
3396 dev_err(&spi->dev,
3397 "Clock-cycle delays for CS not supported in SW mode\n");
3398 return -ENOTSUPP;
3399 }
3400
3401 len = sizeof(struct spi_delay);
3402
3403 /* copy delays to controller */
3404 if (setup)
3405 memcpy(&spi->controller->cs_setup, setup, len);
3406 else
3407 memset(&spi->controller->cs_setup, 0, len);
3408
3409 if (hold)
3410 memcpy(&spi->controller->cs_hold, hold, len);
3411 else
3412 memset(&spi->controller->cs_hold, 0, len);
3413
3414 if (inactive)
3415 memcpy(&spi->controller->cs_inactive, inactive, len);
3416 else
3417 memset(&spi->controller->cs_inactive, 0, len);
3418
3419 return 0;
3420}
3421EXPORT_SYMBOL_GPL(spi_set_cs_timing);
3422
3423static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
3424 struct spi_device *spi)
3425{
3426 int delay1, delay2;
3427
3428 delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
3429 if (delay1 < 0)
3430 return delay1;
3431
3432 delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
3433 if (delay2 < 0)
3434 return delay2;
3435
3436 if (delay1 < delay2)
3437 memcpy(&xfer->word_delay, &spi->word_delay,
3438 sizeof(xfer->word_delay));
3439
3440 return 0;
3441}
3442
3443static int __spi_validate(struct spi_device *spi, struct spi_message *message)
3444{
3445 struct spi_controller *ctlr = spi->controller;
3446 struct spi_transfer *xfer;
3447 int w_size;
3448
3449 if (list_empty(&message->transfers))
3450 return -EINVAL;
3451
3452 /* If an SPI controller does not support toggling the CS line on each
3453 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
3454 * for the CS line, we can emulate the CS-per-word hardware function by
3455 * splitting transfers into one-word transfers and ensuring that
3456 * cs_change is set for each transfer.
3457 */
3458 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
3459 spi->cs_gpiod ||
3460 gpio_is_valid(spi->cs_gpio))) {
3461 size_t maxsize;
3462 int ret;
3463
3464 maxsize = (spi->bits_per_word + 7) / 8;
3465
3466 /* spi_split_transfers_maxsize() requires message->spi */
3467 message->spi = spi;
3468
3469 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
3470 GFP_KERNEL);
3471 if (ret)
3472 return ret;
3473
3474 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3475 /* don't change cs_change on the last entry in the list */
3476 if (list_is_last(&xfer->transfer_list, &message->transfers))
3477 break;
3478 xfer->cs_change = 1;
3479 }
3480 }
3481
3482 /* Half-duplex links include original MicroWire, and ones with
3483 * only one data pin like SPI_3WIRE (switches direction) or where
3484 * either MOSI or MISO is missing. They can also be caused by
3485 * software limitations.
3486 */
3487 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
3488 (spi->mode & SPI_3WIRE)) {
3489 unsigned flags = ctlr->flags;
3490
3491 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3492 if (xfer->rx_buf && xfer->tx_buf)
3493 return -EINVAL;
3494 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
3495 return -EINVAL;
3496 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
3497 return -EINVAL;
3498 }
3499 }
3500
3501 /**
3502 * Set transfer bits_per_word and max speed as spi device default if
3503 * it is not set for this transfer.
3504 * Set transfer tx_nbits and rx_nbits as single transfer default
3505 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
3506 * Ensure transfer word_delay is at least as long as that required by
3507 * device itself.
3508 */
3509 message->frame_length = 0;
3510 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3511 xfer->effective_speed_hz = 0;
3512 message->frame_length += xfer->len;
3513 if (!xfer->bits_per_word)
3514 xfer->bits_per_word = spi->bits_per_word;
3515
3516 if (!xfer->speed_hz)
3517 xfer->speed_hz = spi->max_speed_hz;
3518
3519 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
3520 xfer->speed_hz = ctlr->max_speed_hz;
3521
3522 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
3523 return -EINVAL;
3524
3525 /*
3526 * SPI transfer length should be multiple of SPI word size
3527 * where SPI word size should be power-of-two multiple
3528 */
3529 if (xfer->bits_per_word <= 8)
3530 w_size = 1;
3531 else if (xfer->bits_per_word <= 16)
3532 w_size = 2;
3533 else
3534 w_size = 4;
3535
3536 /* No partial transfers accepted */
3537 if (xfer->len % w_size)
3538 return -EINVAL;
3539
3540 if (xfer->speed_hz && ctlr->min_speed_hz &&
3541 xfer->speed_hz < ctlr->min_speed_hz)
3542 return -EINVAL;
3543
3544 if (xfer->tx_buf && !xfer->tx_nbits)
3545 xfer->tx_nbits = SPI_NBITS_SINGLE;
3546 if (xfer->rx_buf && !xfer->rx_nbits)
3547 xfer->rx_nbits = SPI_NBITS_SINGLE;
3548 /* check transfer tx/rx_nbits:
3549 * 1. check the value matches one of single, dual and quad
3550 * 2. check tx/rx_nbits match the mode in spi_device
3551 */
3552 if (xfer->tx_buf) {
3553 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3554 xfer->tx_nbits != SPI_NBITS_DUAL &&
3555 xfer->tx_nbits != SPI_NBITS_QUAD)
3556 return -EINVAL;
3557 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3558 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3559 return -EINVAL;
3560 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3561 !(spi->mode & SPI_TX_QUAD))
3562 return -EINVAL;
3563 }
3564 /* check transfer rx_nbits */
3565 if (xfer->rx_buf) {
3566 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3567 xfer->rx_nbits != SPI_NBITS_DUAL &&
3568 xfer->rx_nbits != SPI_NBITS_QUAD)
3569 return -EINVAL;
3570 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3571 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3572 return -EINVAL;
3573 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3574 !(spi->mode & SPI_RX_QUAD))
3575 return -EINVAL;
3576 }
3577
3578 if (_spi_xfer_word_delay_update(xfer, spi))
3579 return -EINVAL;
3580 }
3581
3582 message->status = -EINPROGRESS;
3583
3584 return 0;
3585}
3586
3587static int __spi_async(struct spi_device *spi, struct spi_message *message)
3588{
3589 struct spi_controller *ctlr = spi->controller;
3590 struct spi_transfer *xfer;
3591
3592 /*
3593 * Some controllers do not support doing regular SPI transfers. Return
3594 * ENOTSUPP when this is the case.
3595 */
3596 if (!ctlr->transfer)
3597 return -ENOTSUPP;
3598
3599 message->spi = spi;
3600
3601 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
3602 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3603
3604 trace_spi_message_submit(message);
3605
3606 if (!ctlr->ptp_sts_supported) {
3607 list_for_each_entry(xfer, &message->transfers, transfer_list) {
3608 xfer->ptp_sts_word_pre = 0;
3609 ptp_read_system_prets(xfer->ptp_sts);
3610 }
3611 }
3612
3613 return ctlr->transfer(spi, message);
3614}
3615
3616/**
3617 * spi_async - asynchronous SPI transfer
3618 * @spi: device with which data will be exchanged
3619 * @message: describes the data transfers, including completion callback
3620 * Context: any (irqs may be blocked, etc)
3621 *
3622 * This call may be used in_irq and other contexts which can't sleep,
3623 * as well as from task contexts which can sleep.
3624 *
3625 * The completion callback is invoked in a context which can't sleep.
3626 * Before that invocation, the value of message->status is undefined.
3627 * When the callback is issued, message->status holds either zero (to
3628 * indicate complete success) or a negative error code. After that
3629 * callback returns, the driver which issued the transfer request may
3630 * deallocate the associated memory; it's no longer in use by any SPI
3631 * core or controller driver code.
3632 *
3633 * Note that although all messages to a spi_device are handled in
3634 * FIFO order, messages may go to different devices in other orders.
3635 * Some device might be higher priority, or have various "hard" access
3636 * time requirements, for example.
3637 *
3638 * On detection of any fault during the transfer, processing of
3639 * the entire message is aborted, and the device is deselected.
3640 * Until returning from the associated message completion callback,
3641 * no other spi_message queued to that device will be processed.
3642 * (This rule applies equally to all the synchronous transfer calls,
3643 * which are wrappers around this core asynchronous primitive.)
3644 *
3645 * Return: zero on success, else a negative error code.
3646 */
3647int spi_async(struct spi_device *spi, struct spi_message *message)
3648{
3649 struct spi_controller *ctlr = spi->controller;
3650 int ret;
3651 unsigned long flags;
3652
3653 ret = __spi_validate(spi, message);
3654 if (ret != 0)
3655 return ret;
3656
3657 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3658
3659 if (ctlr->bus_lock_flag)
3660 ret = -EBUSY;
3661 else
3662 ret = __spi_async(spi, message);
3663
3664 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3665
3666 return ret;
3667}
3668EXPORT_SYMBOL_GPL(spi_async);
3669
3670/**
3671 * spi_async_locked - version of spi_async with exclusive bus usage
3672 * @spi: device with which data will be exchanged
3673 * @message: describes the data transfers, including completion callback
3674 * Context: any (irqs may be blocked, etc)
3675 *
3676 * This call may be used in_irq and other contexts which can't sleep,
3677 * as well as from task contexts which can sleep.
3678 *
3679 * The completion callback is invoked in a context which can't sleep.
3680 * Before that invocation, the value of message->status is undefined.
3681 * When the callback is issued, message->status holds either zero (to
3682 * indicate complete success) or a negative error code. After that
3683 * callback returns, the driver which issued the transfer request may
3684 * deallocate the associated memory; it's no longer in use by any SPI
3685 * core or controller driver code.
3686 *
3687 * Note that although all messages to a spi_device are handled in
3688 * FIFO order, messages may go to different devices in other orders.
3689 * Some device might be higher priority, or have various "hard" access
3690 * time requirements, for example.
3691 *
3692 * On detection of any fault during the transfer, processing of
3693 * the entire message is aborted, and the device is deselected.
3694 * Until returning from the associated message completion callback,
3695 * no other spi_message queued to that device will be processed.
3696 * (This rule applies equally to all the synchronous transfer calls,
3697 * which are wrappers around this core asynchronous primitive.)
3698 *
3699 * Return: zero on success, else a negative error code.
3700 */
3701int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3702{
3703 struct spi_controller *ctlr = spi->controller;
3704 int ret;
3705 unsigned long flags;
3706
3707 ret = __spi_validate(spi, message);
3708 if (ret != 0)
3709 return ret;
3710
3711 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3712
3713 ret = __spi_async(spi, message);
3714
3715 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3716
3717 return ret;
3718
3719}
3720EXPORT_SYMBOL_GPL(spi_async_locked);
3721
3722/*-------------------------------------------------------------------------*/
3723
3724/* Utility methods for SPI protocol drivers, layered on
3725 * top of the core. Some other utility methods are defined as
3726 * inline functions.
3727 */
3728
3729static void spi_complete(void *arg)
3730{
3731 complete(arg);
3732}
3733
3734static int __spi_sync(struct spi_device *spi, struct spi_message *message)
3735{
3736 DECLARE_COMPLETION_ONSTACK(done);
3737 int status;
3738 struct spi_controller *ctlr = spi->controller;
3739 unsigned long flags;
3740
3741 status = __spi_validate(spi, message);
3742 if (status != 0)
3743 return status;
3744
3745 message->complete = spi_complete;
3746 message->context = &done;
3747 message->spi = spi;
3748
3749 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
3750 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3751
3752 /* If we're not using the legacy transfer method then we will
3753 * try to transfer in the calling context so special case.
3754 * This code would be less tricky if we could remove the
3755 * support for driver implemented message queues.
3756 */
3757 if (ctlr->transfer == spi_queued_transfer) {
3758 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3759
3760 trace_spi_message_submit(message);
3761
3762 status = __spi_queued_transfer(spi, message, false);
3763
3764 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3765 } else {
3766 status = spi_async_locked(spi, message);
3767 }
3768
3769 if (status == 0) {
3770 /* Push out the messages in the calling context if we
3771 * can.
3772 */
3773 if (ctlr->transfer == spi_queued_transfer) {
3774 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
3775 spi_sync_immediate);
3776 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3777 spi_sync_immediate);
3778 __spi_pump_messages(ctlr, false);
3779 }
3780
3781 wait_for_completion(&done);
3782 status = message->status;
3783 }
3784 message->context = NULL;
3785 return status;
3786}
3787
3788/**
3789 * spi_sync - blocking/synchronous SPI data transfers
3790 * @spi: device with which data will be exchanged
3791 * @message: describes the data transfers
3792 * Context: can sleep
3793 *
3794 * This call may only be used from a context that may sleep. The sleep
3795 * is non-interruptible, and has no timeout. Low-overhead controller
3796 * drivers may DMA directly into and out of the message buffers.
3797 *
3798 * Note that the SPI device's chip select is active during the message,
3799 * and then is normally disabled between messages. Drivers for some
3800 * frequently-used devices may want to minimize costs of selecting a chip,
3801 * by leaving it selected in anticipation that the next message will go
3802 * to the same chip. (That may increase power usage.)
3803 *
3804 * Also, the caller is guaranteeing that the memory associated with the
3805 * message will not be freed before this call returns.
3806 *
3807 * Return: zero on success, else a negative error code.
3808 */
3809int spi_sync(struct spi_device *spi, struct spi_message *message)
3810{
3811 int ret;
3812
3813 mutex_lock(&spi->controller->bus_lock_mutex);
3814 ret = __spi_sync(spi, message);
3815 mutex_unlock(&spi->controller->bus_lock_mutex);
3816
3817 return ret;
3818}
3819EXPORT_SYMBOL_GPL(spi_sync);
3820
3821/**
3822 * spi_sync_locked - version of spi_sync with exclusive bus usage
3823 * @spi: device with which data will be exchanged
3824 * @message: describes the data transfers
3825 * Context: can sleep
3826 *
3827 * This call may only be used from a context that may sleep. The sleep
3828 * is non-interruptible, and has no timeout. Low-overhead controller
3829 * drivers may DMA directly into and out of the message buffers.
3830 *
3831 * This call should be used by drivers that require exclusive access to the
3832 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
3833 * be released by a spi_bus_unlock call when the exclusive access is over.
3834 *
3835 * Return: zero on success, else a negative error code.
3836 */
3837int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3838{
3839 return __spi_sync(spi, message);
3840}
3841EXPORT_SYMBOL_GPL(spi_sync_locked);
3842
3843/**
3844 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
3845 * @ctlr: SPI bus master that should be locked for exclusive bus access
3846 * Context: can sleep
3847 *
3848 * This call may only be used from a context that may sleep. The sleep
3849 * is non-interruptible, and has no timeout.
3850 *
3851 * This call should be used by drivers that require exclusive access to the
3852 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3853 * exclusive access is over. Data transfer must be done by spi_sync_locked
3854 * and spi_async_locked calls when the SPI bus lock is held.
3855 *
3856 * Return: always zero.
3857 */
3858int spi_bus_lock(struct spi_controller *ctlr)
3859{
3860 unsigned long flags;
3861
3862 mutex_lock(&ctlr->bus_lock_mutex);
3863
3864 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3865 ctlr->bus_lock_flag = 1;
3866 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
3867
3868 /* mutex remains locked until spi_bus_unlock is called */
3869
3870 return 0;
3871}
3872EXPORT_SYMBOL_GPL(spi_bus_lock);
3873
3874/**
3875 * spi_bus_unlock - release the lock for exclusive SPI bus usage
3876 * @ctlr: SPI bus master that was locked for exclusive bus access
3877 * Context: can sleep
3878 *
3879 * This call may only be used from a context that may sleep. The sleep
3880 * is non-interruptible, and has no timeout.
3881 *
3882 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3883 * call.
3884 *
3885 * Return: always zero.
3886 */
3887int spi_bus_unlock(struct spi_controller *ctlr)
3888{
3889 ctlr->bus_lock_flag = 0;
3890
3891 mutex_unlock(&ctlr->bus_lock_mutex);
3892
3893 return 0;
3894}
3895EXPORT_SYMBOL_GPL(spi_bus_unlock);
3896
3897/* portable code must never pass more than 32 bytes */
3898#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3899
3900static u8 *buf;
3901
3902/**
3903 * spi_write_then_read - SPI synchronous write followed by read
3904 * @spi: device with which data will be exchanged
3905 * @txbuf: data to be written (need not be dma-safe)
3906 * @n_tx: size of txbuf, in bytes
3907 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3908 * @n_rx: size of rxbuf, in bytes
3909 * Context: can sleep
3910 *
3911 * This performs a half duplex MicroWire style transaction with the
3912 * device, sending txbuf and then reading rxbuf. The return value
3913 * is zero for success, else a negative errno status code.
3914 * This call may only be used from a context that may sleep.
3915 *
3916 * Parameters to this routine are always copied using a small buffer.
3917 * Performance-sensitive or bulk transfer code should instead use
3918 * spi_{async,sync}() calls with dma-safe buffers.
3919 *
3920 * Return: zero on success, else a negative error code.
3921 */
3922int spi_write_then_read(struct spi_device *spi,
3923 const void *txbuf, unsigned n_tx,
3924 void *rxbuf, unsigned n_rx)
3925{
3926 static DEFINE_MUTEX(lock);
3927
3928 int status;
3929 struct spi_message message;
3930 struct spi_transfer x[2];
3931 u8 *local_buf;
3932
3933 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3934 * copying here, (as a pure convenience thing), but we can
3935 * keep heap costs out of the hot path unless someone else is
3936 * using the pre-allocated buffer or the transfer is too large.
3937 */
3938 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3939 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3940 GFP_KERNEL | GFP_DMA);
3941 if (!local_buf)
3942 return -ENOMEM;
3943 } else {
3944 local_buf = buf;
3945 }
3946
3947 spi_message_init(&message);
3948 memset(x, 0, sizeof(x));
3949 if (n_tx) {
3950 x[0].len = n_tx;
3951 spi_message_add_tail(&x[0], &message);
3952 }
3953 if (n_rx) {
3954 x[1].len = n_rx;
3955 spi_message_add_tail(&x[1], &message);
3956 }
3957
3958 memcpy(local_buf, txbuf, n_tx);
3959 x[0].tx_buf = local_buf;
3960 x[1].rx_buf = local_buf + n_tx;
3961
3962 /* do the i/o */
3963 status = spi_sync(spi, &message);
3964 if (status == 0)
3965 memcpy(rxbuf, x[1].rx_buf, n_rx);
3966
3967 if (x[0].tx_buf == buf)
3968 mutex_unlock(&lock);
3969 else
3970 kfree(local_buf);
3971
3972 return status;
3973}
3974EXPORT_SYMBOL_GPL(spi_write_then_read);
3975
3976/*-------------------------------------------------------------------------*/
3977
3978#if IS_ENABLED(CONFIG_OF)
3979/* must call put_device() when done with returned spi_device device */
3980struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3981{
3982 struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
3983
3984 return dev ? to_spi_device(dev) : NULL;
3985}
3986EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
3987#endif /* IS_ENABLED(CONFIG_OF) */
3988
3989#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3990/* the spi controllers are not using spi_bus, so we find it with another way */
3991static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
3992{
3993 struct device *dev;
3994
3995 dev = class_find_device_by_of_node(&spi_master_class, node);
3996 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3997 dev = class_find_device_by_of_node(&spi_slave_class, node);
3998 if (!dev)
3999 return NULL;
4000
4001 /* reference got in class_find_device */
4002 return container_of(dev, struct spi_controller, dev);
4003}
4004
4005static int of_spi_notify(struct notifier_block *nb, unsigned long action,
4006 void *arg)
4007{
4008 struct of_reconfig_data *rd = arg;
4009 struct spi_controller *ctlr;
4010 struct spi_device *spi;
4011
4012 switch (of_reconfig_get_state_change(action, arg)) {
4013 case OF_RECONFIG_CHANGE_ADD:
4014 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
4015 if (ctlr == NULL)
4016 return NOTIFY_OK; /* not for us */
4017
4018 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
4019 put_device(&ctlr->dev);
4020 return NOTIFY_OK;
4021 }
4022
4023 spi = of_register_spi_device(ctlr, rd->dn);
4024 put_device(&ctlr->dev);
4025
4026 if (IS_ERR(spi)) {
4027 pr_err("%s: failed to create for '%pOF'\n",
4028 __func__, rd->dn);
4029 of_node_clear_flag(rd->dn, OF_POPULATED);
4030 return notifier_from_errno(PTR_ERR(spi));
4031 }
4032 break;
4033
4034 case OF_RECONFIG_CHANGE_REMOVE:
4035 /* already depopulated? */
4036 if (!of_node_check_flag(rd->dn, OF_POPULATED))
4037 return NOTIFY_OK;
4038
4039 /* find our device by node */
4040 spi = of_find_spi_device_by_node(rd->dn);
4041 if (spi == NULL)
4042 return NOTIFY_OK; /* no? not meant for us */
4043
4044 /* unregister takes one ref away */
4045 spi_unregister_device(spi);
4046
4047 /* and put the reference of the find */
4048 put_device(&spi->dev);
4049 break;
4050 }
4051
4052 return NOTIFY_OK;
4053}
4054
4055static struct notifier_block spi_of_notifier = {
4056 .notifier_call = of_spi_notify,
4057};
4058#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4059extern struct notifier_block spi_of_notifier;
4060#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
4061
4062#if IS_ENABLED(CONFIG_ACPI)
4063static int spi_acpi_controller_match(struct device *dev, const void *data)
4064{
4065 return ACPI_COMPANION(dev->parent) == data;
4066}
4067
4068static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
4069{
4070 struct device *dev;
4071
4072 dev = class_find_device(&spi_master_class, NULL, adev,
4073 spi_acpi_controller_match);
4074 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
4075 dev = class_find_device(&spi_slave_class, NULL, adev,
4076 spi_acpi_controller_match);
4077 if (!dev)
4078 return NULL;
4079
4080 return container_of(dev, struct spi_controller, dev);
4081}
4082
4083static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
4084{
4085 struct device *dev;
4086
4087 dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
4088 return to_spi_device(dev);
4089}
4090
4091static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
4092 void *arg)
4093{
4094 struct acpi_device *adev = arg;
4095 struct spi_controller *ctlr;
4096 struct spi_device *spi;
4097
4098 switch (value) {
4099 case ACPI_RECONFIG_DEVICE_ADD:
4100 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
4101 if (!ctlr)
4102 break;
4103
4104 acpi_register_spi_device(ctlr, adev);
4105 put_device(&ctlr->dev);
4106 break;
4107 case ACPI_RECONFIG_DEVICE_REMOVE:
4108 if (!acpi_device_enumerated(adev))
4109 break;
4110
4111 spi = acpi_spi_find_device_by_adev(adev);
4112 if (!spi)
4113 break;
4114
4115 spi_unregister_device(spi);
4116 put_device(&spi->dev);
4117 break;
4118 }
4119
4120 return NOTIFY_OK;
4121}
4122
4123static struct notifier_block spi_acpi_notifier = {
4124 .notifier_call = acpi_spi_notify,
4125};
4126#else
4127extern struct notifier_block spi_acpi_notifier;
4128#endif
4129
4130static int __init spi_init(void)
4131{
4132 int status;
4133
4134 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
4135 if (!buf) {
4136 status = -ENOMEM;
4137 goto err0;
4138 }
4139
4140 status = bus_register(&spi_bus_type);
4141 if (status < 0)
4142 goto err1;
4143
4144 status = class_register(&spi_master_class);
4145 if (status < 0)
4146 goto err2;
4147
4148 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
4149 status = class_register(&spi_slave_class);
4150 if (status < 0)
4151 goto err3;
4152 }
4153
4154 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
4155 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
4156 if (IS_ENABLED(CONFIG_ACPI))
4157 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
4158
4159 return 0;
4160
4161err3:
4162 class_unregister(&spi_master_class);
4163err2:
4164 bus_unregister(&spi_bus_type);
4165err1:
4166 kfree(buf);
4167 buf = NULL;
4168err0:
4169 return status;
4170}
4171
4172/* board_info is normally registered in arch_initcall(),
4173 * but even essential drivers wait till later
4174 *
4175 * REVISIT only boardinfo really needs static linking. the rest (device and
4176 * driver registration) _could_ be dynamically linked (modular) ... costs
4177 * include needing to have boardinfo data structures be much more public.
4178 */
4179postcore_initcall(spi_init);