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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/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);
1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/cache.h>
22#include <linux/dma-mapping.h>
23#include <linux/dmaengine.h>
24#include <linux/mutex.h>
25#include <linux/of_device.h>
26#include <linux/of_irq.h>
27#include <linux/clk/clk-conf.h>
28#include <linux/slab.h>
29#include <linux/mod_devicetable.h>
30#include <linux/spi/spi.h>
31#include <linux/of_gpio.h>
32#include <linux/pm_runtime.h>
33#include <linux/pm_domain.h>
34#include <linux/export.h>
35#include <linux/sched/rt.h>
36#include <linux/delay.h>
37#include <linux/kthread.h>
38#include <linux/ioport.h>
39#include <linux/acpi.h>
40#include <linux/highmem.h>
41
42#define CREATE_TRACE_POINTS
43#include <trace/events/spi.h>
44
45static void spidev_release(struct device *dev)
46{
47 struct spi_device *spi = to_spi_device(dev);
48
49 /* spi masters may cleanup for released devices */
50 if (spi->master->cleanup)
51 spi->master->cleanup(spi);
52
53 spi_master_put(spi->master);
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
71#define SPI_STATISTICS_ATTRS(field, file) \
72static ssize_t spi_master_##field##_show(struct device *dev, \
73 struct device_attribute *attr, \
74 char *buf) \
75{ \
76 struct spi_master *master = container_of(dev, \
77 struct spi_master, dev); \
78 return spi_statistics_##field##_show(&master->statistics, buf); \
79} \
80static struct device_attribute dev_attr_spi_master_##field = { \
81 .attr = { .name = file, .mode = S_IRUGO }, \
82 .show = spi_master_##field##_show, \
83}; \
84static ssize_t spi_device_##field##_show(struct device *dev, \
85 struct device_attribute *attr, \
86 char *buf) \
87{ \
88 struct spi_device *spi = to_spi_device(dev); \
89 return spi_statistics_##field##_show(&spi->statistics, buf); \
90} \
91static struct device_attribute dev_attr_spi_device_##field = { \
92 .attr = { .name = file, .mode = S_IRUGO }, \
93 .show = spi_device_##field##_show, \
94}
95
96#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
97static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
98 char *buf) \
99{ \
100 unsigned long flags; \
101 ssize_t len; \
102 spin_lock_irqsave(&stat->lock, flags); \
103 len = sprintf(buf, format_string, stat->field); \
104 spin_unlock_irqrestore(&stat->lock, flags); \
105 return len; \
106} \
107SPI_STATISTICS_ATTRS(name, file)
108
109#define SPI_STATISTICS_SHOW(field, format_string) \
110 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
111 field, format_string)
112
113SPI_STATISTICS_SHOW(messages, "%lu");
114SPI_STATISTICS_SHOW(transfers, "%lu");
115SPI_STATISTICS_SHOW(errors, "%lu");
116SPI_STATISTICS_SHOW(timedout, "%lu");
117
118SPI_STATISTICS_SHOW(spi_sync, "%lu");
119SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
120SPI_STATISTICS_SHOW(spi_async, "%lu");
121
122SPI_STATISTICS_SHOW(bytes, "%llu");
123SPI_STATISTICS_SHOW(bytes_rx, "%llu");
124SPI_STATISTICS_SHOW(bytes_tx, "%llu");
125
126#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
127 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
128 "transfer_bytes_histo_" number, \
129 transfer_bytes_histo[index], "%lu")
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
146SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
147
148SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
149
150static struct attribute *spi_dev_attrs[] = {
151 &dev_attr_modalias.attr,
152 NULL,
153};
154
155static const struct attribute_group spi_dev_group = {
156 .attrs = spi_dev_attrs,
157};
158
159static struct attribute *spi_device_statistics_attrs[] = {
160 &dev_attr_spi_device_messages.attr,
161 &dev_attr_spi_device_transfers.attr,
162 &dev_attr_spi_device_errors.attr,
163 &dev_attr_spi_device_timedout.attr,
164 &dev_attr_spi_device_spi_sync.attr,
165 &dev_attr_spi_device_spi_sync_immediate.attr,
166 &dev_attr_spi_device_spi_async.attr,
167 &dev_attr_spi_device_bytes.attr,
168 &dev_attr_spi_device_bytes_rx.attr,
169 &dev_attr_spi_device_bytes_tx.attr,
170 &dev_attr_spi_device_transfer_bytes_histo0.attr,
171 &dev_attr_spi_device_transfer_bytes_histo1.attr,
172 &dev_attr_spi_device_transfer_bytes_histo2.attr,
173 &dev_attr_spi_device_transfer_bytes_histo3.attr,
174 &dev_attr_spi_device_transfer_bytes_histo4.attr,
175 &dev_attr_spi_device_transfer_bytes_histo5.attr,
176 &dev_attr_spi_device_transfer_bytes_histo6.attr,
177 &dev_attr_spi_device_transfer_bytes_histo7.attr,
178 &dev_attr_spi_device_transfer_bytes_histo8.attr,
179 &dev_attr_spi_device_transfer_bytes_histo9.attr,
180 &dev_attr_spi_device_transfer_bytes_histo10.attr,
181 &dev_attr_spi_device_transfer_bytes_histo11.attr,
182 &dev_attr_spi_device_transfer_bytes_histo12.attr,
183 &dev_attr_spi_device_transfer_bytes_histo13.attr,
184 &dev_attr_spi_device_transfer_bytes_histo14.attr,
185 &dev_attr_spi_device_transfer_bytes_histo15.attr,
186 &dev_attr_spi_device_transfer_bytes_histo16.attr,
187 &dev_attr_spi_device_transfers_split_maxsize.attr,
188 NULL,
189};
190
191static const struct attribute_group spi_device_statistics_group = {
192 .name = "statistics",
193 .attrs = spi_device_statistics_attrs,
194};
195
196static const struct attribute_group *spi_dev_groups[] = {
197 &spi_dev_group,
198 &spi_device_statistics_group,
199 NULL,
200};
201
202static struct attribute *spi_master_statistics_attrs[] = {
203 &dev_attr_spi_master_messages.attr,
204 &dev_attr_spi_master_transfers.attr,
205 &dev_attr_spi_master_errors.attr,
206 &dev_attr_spi_master_timedout.attr,
207 &dev_attr_spi_master_spi_sync.attr,
208 &dev_attr_spi_master_spi_sync_immediate.attr,
209 &dev_attr_spi_master_spi_async.attr,
210 &dev_attr_spi_master_bytes.attr,
211 &dev_attr_spi_master_bytes_rx.attr,
212 &dev_attr_spi_master_bytes_tx.attr,
213 &dev_attr_spi_master_transfer_bytes_histo0.attr,
214 &dev_attr_spi_master_transfer_bytes_histo1.attr,
215 &dev_attr_spi_master_transfer_bytes_histo2.attr,
216 &dev_attr_spi_master_transfer_bytes_histo3.attr,
217 &dev_attr_spi_master_transfer_bytes_histo4.attr,
218 &dev_attr_spi_master_transfer_bytes_histo5.attr,
219 &dev_attr_spi_master_transfer_bytes_histo6.attr,
220 &dev_attr_spi_master_transfer_bytes_histo7.attr,
221 &dev_attr_spi_master_transfer_bytes_histo8.attr,
222 &dev_attr_spi_master_transfer_bytes_histo9.attr,
223 &dev_attr_spi_master_transfer_bytes_histo10.attr,
224 &dev_attr_spi_master_transfer_bytes_histo11.attr,
225 &dev_attr_spi_master_transfer_bytes_histo12.attr,
226 &dev_attr_spi_master_transfer_bytes_histo13.attr,
227 &dev_attr_spi_master_transfer_bytes_histo14.attr,
228 &dev_attr_spi_master_transfer_bytes_histo15.attr,
229 &dev_attr_spi_master_transfer_bytes_histo16.attr,
230 &dev_attr_spi_master_transfers_split_maxsize.attr,
231 NULL,
232};
233
234static const struct attribute_group spi_master_statistics_group = {
235 .name = "statistics",
236 .attrs = spi_master_statistics_attrs,
237};
238
239static const struct attribute_group *spi_master_groups[] = {
240 &spi_master_statistics_group,
241 NULL,
242};
243
244void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
245 struct spi_transfer *xfer,
246 struct spi_master *master)
247{
248 unsigned long flags;
249 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
250
251 if (l2len < 0)
252 l2len = 0;
253
254 spin_lock_irqsave(&stats->lock, flags);
255
256 stats->transfers++;
257 stats->transfer_bytes_histo[l2len]++;
258
259 stats->bytes += xfer->len;
260 if ((xfer->tx_buf) &&
261 (xfer->tx_buf != master->dummy_tx))
262 stats->bytes_tx += xfer->len;
263 if ((xfer->rx_buf) &&
264 (xfer->rx_buf != master->dummy_rx))
265 stats->bytes_rx += xfer->len;
266
267 spin_unlock_irqrestore(&stats->lock, flags);
268}
269EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
270
271/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
272 * and the sysfs version makes coldplug work too.
273 */
274
275static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
276 const struct spi_device *sdev)
277{
278 while (id->name[0]) {
279 if (!strcmp(sdev->modalias, id->name))
280 return id;
281 id++;
282 }
283 return NULL;
284}
285
286const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
287{
288 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
289
290 return spi_match_id(sdrv->id_table, sdev);
291}
292EXPORT_SYMBOL_GPL(spi_get_device_id);
293
294static int spi_match_device(struct device *dev, struct device_driver *drv)
295{
296 const struct spi_device *spi = to_spi_device(dev);
297 const struct spi_driver *sdrv = to_spi_driver(drv);
298
299 /* Attempt an OF style match */
300 if (of_driver_match_device(dev, drv))
301 return 1;
302
303 /* Then try ACPI */
304 if (acpi_driver_match_device(dev, drv))
305 return 1;
306
307 if (sdrv->id_table)
308 return !!spi_match_id(sdrv->id_table, spi);
309
310 return strcmp(spi->modalias, drv->name) == 0;
311}
312
313static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
314{
315 const struct spi_device *spi = to_spi_device(dev);
316 int rc;
317
318 rc = acpi_device_uevent_modalias(dev, env);
319 if (rc != -ENODEV)
320 return rc;
321
322 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
323 return 0;
324}
325
326struct bus_type spi_bus_type = {
327 .name = "spi",
328 .dev_groups = spi_dev_groups,
329 .match = spi_match_device,
330 .uevent = spi_uevent,
331};
332EXPORT_SYMBOL_GPL(spi_bus_type);
333
334
335static int spi_drv_probe(struct device *dev)
336{
337 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
338 struct spi_device *spi = to_spi_device(dev);
339 int ret;
340
341 ret = of_clk_set_defaults(dev->of_node, false);
342 if (ret)
343 return ret;
344
345 if (dev->of_node) {
346 spi->irq = of_irq_get(dev->of_node, 0);
347 if (spi->irq == -EPROBE_DEFER)
348 return -EPROBE_DEFER;
349 if (spi->irq < 0)
350 spi->irq = 0;
351 }
352
353 ret = dev_pm_domain_attach(dev, true);
354 if (ret != -EPROBE_DEFER) {
355 ret = sdrv->probe(spi);
356 if (ret)
357 dev_pm_domain_detach(dev, true);
358 }
359
360 return ret;
361}
362
363static int spi_drv_remove(struct device *dev)
364{
365 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
366 int ret;
367
368 ret = sdrv->remove(to_spi_device(dev));
369 dev_pm_domain_detach(dev, true);
370
371 return ret;
372}
373
374static void spi_drv_shutdown(struct device *dev)
375{
376 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
377
378 sdrv->shutdown(to_spi_device(dev));
379}
380
381/**
382 * __spi_register_driver - register a SPI driver
383 * @owner: owner module of the driver to register
384 * @sdrv: the driver to register
385 * Context: can sleep
386 *
387 * Return: zero on success, else a negative error code.
388 */
389int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
390{
391 sdrv->driver.owner = owner;
392 sdrv->driver.bus = &spi_bus_type;
393 if (sdrv->probe)
394 sdrv->driver.probe = spi_drv_probe;
395 if (sdrv->remove)
396 sdrv->driver.remove = spi_drv_remove;
397 if (sdrv->shutdown)
398 sdrv->driver.shutdown = spi_drv_shutdown;
399 return driver_register(&sdrv->driver);
400}
401EXPORT_SYMBOL_GPL(__spi_register_driver);
402
403/*-------------------------------------------------------------------------*/
404
405/* SPI devices should normally not be created by SPI device drivers; that
406 * would make them board-specific. Similarly with SPI master drivers.
407 * Device registration normally goes into like arch/.../mach.../board-YYY.c
408 * with other readonly (flashable) information about mainboard devices.
409 */
410
411struct boardinfo {
412 struct list_head list;
413 struct spi_board_info board_info;
414};
415
416static LIST_HEAD(board_list);
417static LIST_HEAD(spi_master_list);
418
419/*
420 * Used to protect add/del opertion for board_info list and
421 * spi_master list, and their matching process
422 */
423static DEFINE_MUTEX(board_lock);
424
425/**
426 * spi_alloc_device - Allocate a new SPI device
427 * @master: Controller to which device is connected
428 * Context: can sleep
429 *
430 * Allows a driver to allocate and initialize a spi_device without
431 * registering it immediately. This allows a driver to directly
432 * fill the spi_device with device parameters before calling
433 * spi_add_device() on it.
434 *
435 * Caller is responsible to call spi_add_device() on the returned
436 * spi_device structure to add it to the SPI master. If the caller
437 * needs to discard the spi_device without adding it, then it should
438 * call spi_dev_put() on it.
439 *
440 * Return: a pointer to the new device, or NULL.
441 */
442struct spi_device *spi_alloc_device(struct spi_master *master)
443{
444 struct spi_device *spi;
445
446 if (!spi_master_get(master))
447 return NULL;
448
449 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
450 if (!spi) {
451 spi_master_put(master);
452 return NULL;
453 }
454
455 spi->master = master;
456 spi->dev.parent = &master->dev;
457 spi->dev.bus = &spi_bus_type;
458 spi->dev.release = spidev_release;
459 spi->cs_gpio = -ENOENT;
460
461 spin_lock_init(&spi->statistics.lock);
462
463 device_initialize(&spi->dev);
464 return spi;
465}
466EXPORT_SYMBOL_GPL(spi_alloc_device);
467
468static void spi_dev_set_name(struct spi_device *spi)
469{
470 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
471
472 if (adev) {
473 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
474 return;
475 }
476
477 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
478 spi->chip_select);
479}
480
481static int spi_dev_check(struct device *dev, void *data)
482{
483 struct spi_device *spi = to_spi_device(dev);
484 struct spi_device *new_spi = data;
485
486 if (spi->master == new_spi->master &&
487 spi->chip_select == new_spi->chip_select)
488 return -EBUSY;
489 return 0;
490}
491
492/**
493 * spi_add_device - Add spi_device allocated with spi_alloc_device
494 * @spi: spi_device to register
495 *
496 * Companion function to spi_alloc_device. Devices allocated with
497 * spi_alloc_device can be added onto the spi bus with this function.
498 *
499 * Return: 0 on success; negative errno on failure
500 */
501int spi_add_device(struct spi_device *spi)
502{
503 static DEFINE_MUTEX(spi_add_lock);
504 struct spi_master *master = spi->master;
505 struct device *dev = master->dev.parent;
506 int status;
507
508 /* Chipselects are numbered 0..max; validate. */
509 if (spi->chip_select >= master->num_chipselect) {
510 dev_err(dev, "cs%d >= max %d\n",
511 spi->chip_select,
512 master->num_chipselect);
513 return -EINVAL;
514 }
515
516 /* Set the bus ID string */
517 spi_dev_set_name(spi);
518
519 /* We need to make sure there's no other device with this
520 * chipselect **BEFORE** we call setup(), else we'll trash
521 * its configuration. Lock against concurrent add() calls.
522 */
523 mutex_lock(&spi_add_lock);
524
525 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
526 if (status) {
527 dev_err(dev, "chipselect %d already in use\n",
528 spi->chip_select);
529 goto done;
530 }
531
532 if (master->cs_gpios)
533 spi->cs_gpio = master->cs_gpios[spi->chip_select];
534
535 /* Drivers may modify this initial i/o setup, but will
536 * normally rely on the device being setup. Devices
537 * using SPI_CS_HIGH can't coexist well otherwise...
538 */
539 status = spi_setup(spi);
540 if (status < 0) {
541 dev_err(dev, "can't setup %s, status %d\n",
542 dev_name(&spi->dev), status);
543 goto done;
544 }
545
546 /* Device may be bound to an active driver when this returns */
547 status = device_add(&spi->dev);
548 if (status < 0)
549 dev_err(dev, "can't add %s, status %d\n",
550 dev_name(&spi->dev), status);
551 else
552 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
553
554done:
555 mutex_unlock(&spi_add_lock);
556 return status;
557}
558EXPORT_SYMBOL_GPL(spi_add_device);
559
560/**
561 * spi_new_device - instantiate one new SPI device
562 * @master: Controller to which device is connected
563 * @chip: Describes the SPI device
564 * Context: can sleep
565 *
566 * On typical mainboards, this is purely internal; and it's not needed
567 * after board init creates the hard-wired devices. Some development
568 * platforms may not be able to use spi_register_board_info though, and
569 * this is exported so that for example a USB or parport based adapter
570 * driver could add devices (which it would learn about out-of-band).
571 *
572 * Return: the new device, or NULL.
573 */
574struct spi_device *spi_new_device(struct spi_master *master,
575 struct spi_board_info *chip)
576{
577 struct spi_device *proxy;
578 int status;
579
580 /* NOTE: caller did any chip->bus_num checks necessary.
581 *
582 * Also, unless we change the return value convention to use
583 * error-or-pointer (not NULL-or-pointer), troubleshootability
584 * suggests syslogged diagnostics are best here (ugh).
585 */
586
587 proxy = spi_alloc_device(master);
588 if (!proxy)
589 return NULL;
590
591 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
592
593 proxy->chip_select = chip->chip_select;
594 proxy->max_speed_hz = chip->max_speed_hz;
595 proxy->mode = chip->mode;
596 proxy->irq = chip->irq;
597 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
598 proxy->dev.platform_data = (void *) chip->platform_data;
599 proxy->controller_data = chip->controller_data;
600 proxy->controller_state = NULL;
601
602 status = spi_add_device(proxy);
603 if (status < 0) {
604 spi_dev_put(proxy);
605 return NULL;
606 }
607
608 return proxy;
609}
610EXPORT_SYMBOL_GPL(spi_new_device);
611
612/**
613 * spi_unregister_device - unregister a single SPI device
614 * @spi: spi_device to unregister
615 *
616 * Start making the passed SPI device vanish. Normally this would be handled
617 * by spi_unregister_master().
618 */
619void spi_unregister_device(struct spi_device *spi)
620{
621 if (!spi)
622 return;
623
624 if (spi->dev.of_node)
625 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
626 if (ACPI_COMPANION(&spi->dev))
627 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
628 device_unregister(&spi->dev);
629}
630EXPORT_SYMBOL_GPL(spi_unregister_device);
631
632static void spi_match_master_to_boardinfo(struct spi_master *master,
633 struct spi_board_info *bi)
634{
635 struct spi_device *dev;
636
637 if (master->bus_num != bi->bus_num)
638 return;
639
640 dev = spi_new_device(master, bi);
641 if (!dev)
642 dev_err(master->dev.parent, "can't create new device for %s\n",
643 bi->modalias);
644}
645
646/**
647 * spi_register_board_info - register SPI devices for a given board
648 * @info: array of chip descriptors
649 * @n: how many descriptors are provided
650 * Context: can sleep
651 *
652 * Board-specific early init code calls this (probably during arch_initcall)
653 * with segments of the SPI device table. Any device nodes are created later,
654 * after the relevant parent SPI controller (bus_num) is defined. We keep
655 * this table of devices forever, so that reloading a controller driver will
656 * not make Linux forget about these hard-wired devices.
657 *
658 * Other code can also call this, e.g. a particular add-on board might provide
659 * SPI devices through its expansion connector, so code initializing that board
660 * would naturally declare its SPI devices.
661 *
662 * The board info passed can safely be __initdata ... but be careful of
663 * any embedded pointers (platform_data, etc), they're copied as-is.
664 *
665 * Return: zero on success, else a negative error code.
666 */
667int spi_register_board_info(struct spi_board_info const *info, unsigned n)
668{
669 struct boardinfo *bi;
670 int i;
671
672 if (!n)
673 return -EINVAL;
674
675 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
676 if (!bi)
677 return -ENOMEM;
678
679 for (i = 0; i < n; i++, bi++, info++) {
680 struct spi_master *master;
681
682 memcpy(&bi->board_info, info, sizeof(*info));
683 mutex_lock(&board_lock);
684 list_add_tail(&bi->list, &board_list);
685 list_for_each_entry(master, &spi_master_list, list)
686 spi_match_master_to_boardinfo(master, &bi->board_info);
687 mutex_unlock(&board_lock);
688 }
689
690 return 0;
691}
692
693/*-------------------------------------------------------------------------*/
694
695static void spi_set_cs(struct spi_device *spi, bool enable)
696{
697 if (spi->mode & SPI_CS_HIGH)
698 enable = !enable;
699
700 if (gpio_is_valid(spi->cs_gpio)) {
701 gpio_set_value(spi->cs_gpio, !enable);
702 /* Some SPI masters need both GPIO CS & slave_select */
703 if ((spi->master->flags & SPI_MASTER_GPIO_SS) &&
704 spi->master->set_cs)
705 spi->master->set_cs(spi, !enable);
706 } else if (spi->master->set_cs) {
707 spi->master->set_cs(spi, !enable);
708 }
709}
710
711#ifdef CONFIG_HAS_DMA
712static int spi_map_buf(struct spi_master *master, struct device *dev,
713 struct sg_table *sgt, void *buf, size_t len,
714 enum dma_data_direction dir)
715{
716 const bool vmalloced_buf = is_vmalloc_addr(buf);
717 unsigned int max_seg_size = dma_get_max_seg_size(dev);
718#ifdef CONFIG_HIGHMEM
719 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
720 (unsigned long)buf < (PKMAP_BASE +
721 (LAST_PKMAP * PAGE_SIZE)));
722#else
723 const bool kmap_buf = false;
724#endif
725 int desc_len;
726 int sgs;
727 struct page *vm_page;
728 struct scatterlist *sg;
729 void *sg_buf;
730 size_t min;
731 int i, ret;
732
733 if (vmalloced_buf || kmap_buf) {
734 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
735 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
736 } else if (virt_addr_valid(buf)) {
737 desc_len = min_t(int, max_seg_size, master->max_dma_len);
738 sgs = DIV_ROUND_UP(len, desc_len);
739 } else {
740 return -EINVAL;
741 }
742
743 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
744 if (ret != 0)
745 return ret;
746
747 sg = &sgt->sgl[0];
748 for (i = 0; i < sgs; i++) {
749
750 if (vmalloced_buf || kmap_buf) {
751 min = min_t(size_t,
752 len, desc_len - offset_in_page(buf));
753 if (vmalloced_buf)
754 vm_page = vmalloc_to_page(buf);
755 else
756 vm_page = kmap_to_page(buf);
757 if (!vm_page) {
758 sg_free_table(sgt);
759 return -ENOMEM;
760 }
761 sg_set_page(sg, vm_page,
762 min, offset_in_page(buf));
763 } else {
764 min = min_t(size_t, len, desc_len);
765 sg_buf = buf;
766 sg_set_buf(sg, sg_buf, min);
767 }
768
769 buf += min;
770 len -= min;
771 sg = sg_next(sg);
772 }
773
774 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
775 if (!ret)
776 ret = -ENOMEM;
777 if (ret < 0) {
778 sg_free_table(sgt);
779 return ret;
780 }
781
782 sgt->nents = ret;
783
784 return 0;
785}
786
787static void spi_unmap_buf(struct spi_master *master, struct device *dev,
788 struct sg_table *sgt, enum dma_data_direction dir)
789{
790 if (sgt->orig_nents) {
791 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
792 sg_free_table(sgt);
793 }
794}
795
796static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
797{
798 struct device *tx_dev, *rx_dev;
799 struct spi_transfer *xfer;
800 int ret;
801
802 if (!master->can_dma)
803 return 0;
804
805 if (master->dma_tx)
806 tx_dev = master->dma_tx->device->dev;
807 else
808 tx_dev = &master->dev;
809
810 if (master->dma_rx)
811 rx_dev = master->dma_rx->device->dev;
812 else
813 rx_dev = &master->dev;
814
815 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
816 if (!master->can_dma(master, msg->spi, xfer))
817 continue;
818
819 if (xfer->tx_buf != NULL) {
820 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
821 (void *)xfer->tx_buf, xfer->len,
822 DMA_TO_DEVICE);
823 if (ret != 0)
824 return ret;
825 }
826
827 if (xfer->rx_buf != NULL) {
828 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
829 xfer->rx_buf, xfer->len,
830 DMA_FROM_DEVICE);
831 if (ret != 0) {
832 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
833 DMA_TO_DEVICE);
834 return ret;
835 }
836 }
837 }
838
839 master->cur_msg_mapped = true;
840
841 return 0;
842}
843
844static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
845{
846 struct spi_transfer *xfer;
847 struct device *tx_dev, *rx_dev;
848
849 if (!master->cur_msg_mapped || !master->can_dma)
850 return 0;
851
852 if (master->dma_tx)
853 tx_dev = master->dma_tx->device->dev;
854 else
855 tx_dev = &master->dev;
856
857 if (master->dma_rx)
858 rx_dev = master->dma_rx->device->dev;
859 else
860 rx_dev = &master->dev;
861
862 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
863 if (!master->can_dma(master, msg->spi, xfer))
864 continue;
865
866 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
867 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
868 }
869
870 return 0;
871}
872#else /* !CONFIG_HAS_DMA */
873static inline int spi_map_buf(struct spi_master *master,
874 struct device *dev, struct sg_table *sgt,
875 void *buf, size_t len,
876 enum dma_data_direction dir)
877{
878 return -EINVAL;
879}
880
881static inline void spi_unmap_buf(struct spi_master *master,
882 struct device *dev, struct sg_table *sgt,
883 enum dma_data_direction dir)
884{
885}
886
887static inline int __spi_map_msg(struct spi_master *master,
888 struct spi_message *msg)
889{
890 return 0;
891}
892
893static inline int __spi_unmap_msg(struct spi_master *master,
894 struct spi_message *msg)
895{
896 return 0;
897}
898#endif /* !CONFIG_HAS_DMA */
899
900static inline int spi_unmap_msg(struct spi_master *master,
901 struct spi_message *msg)
902{
903 struct spi_transfer *xfer;
904
905 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
906 /*
907 * Restore the original value of tx_buf or rx_buf if they are
908 * NULL.
909 */
910 if (xfer->tx_buf == master->dummy_tx)
911 xfer->tx_buf = NULL;
912 if (xfer->rx_buf == master->dummy_rx)
913 xfer->rx_buf = NULL;
914 }
915
916 return __spi_unmap_msg(master, msg);
917}
918
919static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
920{
921 struct spi_transfer *xfer;
922 void *tmp;
923 unsigned int max_tx, max_rx;
924
925 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
926 max_tx = 0;
927 max_rx = 0;
928
929 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
930 if ((master->flags & SPI_MASTER_MUST_TX) &&
931 !xfer->tx_buf)
932 max_tx = max(xfer->len, max_tx);
933 if ((master->flags & SPI_MASTER_MUST_RX) &&
934 !xfer->rx_buf)
935 max_rx = max(xfer->len, max_rx);
936 }
937
938 if (max_tx) {
939 tmp = krealloc(master->dummy_tx, max_tx,
940 GFP_KERNEL | GFP_DMA);
941 if (!tmp)
942 return -ENOMEM;
943 master->dummy_tx = tmp;
944 memset(tmp, 0, max_tx);
945 }
946
947 if (max_rx) {
948 tmp = krealloc(master->dummy_rx, max_rx,
949 GFP_KERNEL | GFP_DMA);
950 if (!tmp)
951 return -ENOMEM;
952 master->dummy_rx = tmp;
953 }
954
955 if (max_tx || max_rx) {
956 list_for_each_entry(xfer, &msg->transfers,
957 transfer_list) {
958 if (!xfer->tx_buf)
959 xfer->tx_buf = master->dummy_tx;
960 if (!xfer->rx_buf)
961 xfer->rx_buf = master->dummy_rx;
962 }
963 }
964 }
965
966 return __spi_map_msg(master, msg);
967}
968
969/*
970 * spi_transfer_one_message - Default implementation of transfer_one_message()
971 *
972 * This is a standard implementation of transfer_one_message() for
973 * drivers which implement a transfer_one() operation. It provides
974 * standard handling of delays and chip select management.
975 */
976static int spi_transfer_one_message(struct spi_master *master,
977 struct spi_message *msg)
978{
979 struct spi_transfer *xfer;
980 bool keep_cs = false;
981 int ret = 0;
982 unsigned long long ms = 1;
983 struct spi_statistics *statm = &master->statistics;
984 struct spi_statistics *stats = &msg->spi->statistics;
985
986 spi_set_cs(msg->spi, true);
987
988 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
989 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
990
991 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
992 trace_spi_transfer_start(msg, xfer);
993
994 spi_statistics_add_transfer_stats(statm, xfer, master);
995 spi_statistics_add_transfer_stats(stats, xfer, master);
996
997 if (xfer->tx_buf || xfer->rx_buf) {
998 reinit_completion(&master->xfer_completion);
999
1000 ret = master->transfer_one(master, msg->spi, xfer);
1001 if (ret < 0) {
1002 SPI_STATISTICS_INCREMENT_FIELD(statm,
1003 errors);
1004 SPI_STATISTICS_INCREMENT_FIELD(stats,
1005 errors);
1006 dev_err(&msg->spi->dev,
1007 "SPI transfer failed: %d\n", ret);
1008 goto out;
1009 }
1010
1011 if (ret > 0) {
1012 ret = 0;
1013 ms = 8LL * 1000LL * xfer->len;
1014 do_div(ms, xfer->speed_hz);
1015 ms += ms + 100; /* some tolerance */
1016
1017 if (ms > UINT_MAX)
1018 ms = UINT_MAX;
1019
1020 ms = wait_for_completion_timeout(&master->xfer_completion,
1021 msecs_to_jiffies(ms));
1022 }
1023
1024 if (ms == 0) {
1025 SPI_STATISTICS_INCREMENT_FIELD(statm,
1026 timedout);
1027 SPI_STATISTICS_INCREMENT_FIELD(stats,
1028 timedout);
1029 dev_err(&msg->spi->dev,
1030 "SPI transfer timed out\n");
1031 msg->status = -ETIMEDOUT;
1032 }
1033 } else {
1034 if (xfer->len)
1035 dev_err(&msg->spi->dev,
1036 "Bufferless transfer has length %u\n",
1037 xfer->len);
1038 }
1039
1040 trace_spi_transfer_stop(msg, xfer);
1041
1042 if (msg->status != -EINPROGRESS)
1043 goto out;
1044
1045 if (xfer->delay_usecs) {
1046 u16 us = xfer->delay_usecs;
1047
1048 if (us <= 10)
1049 udelay(us);
1050 else
1051 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1052 }
1053
1054 if (xfer->cs_change) {
1055 if (list_is_last(&xfer->transfer_list,
1056 &msg->transfers)) {
1057 keep_cs = true;
1058 } else {
1059 spi_set_cs(msg->spi, false);
1060 udelay(10);
1061 spi_set_cs(msg->spi, true);
1062 }
1063 }
1064
1065 msg->actual_length += xfer->len;
1066 }
1067
1068out:
1069 if (ret != 0 || !keep_cs)
1070 spi_set_cs(msg->spi, false);
1071
1072 if (msg->status == -EINPROGRESS)
1073 msg->status = ret;
1074
1075 if (msg->status && master->handle_err)
1076 master->handle_err(master, msg);
1077
1078 spi_res_release(master, msg);
1079
1080 spi_finalize_current_message(master);
1081
1082 return ret;
1083}
1084
1085/**
1086 * spi_finalize_current_transfer - report completion of a transfer
1087 * @master: the master reporting completion
1088 *
1089 * Called by SPI drivers using the core transfer_one_message()
1090 * implementation to notify it that the current interrupt driven
1091 * transfer has finished and the next one may be scheduled.
1092 */
1093void spi_finalize_current_transfer(struct spi_master *master)
1094{
1095 complete(&master->xfer_completion);
1096}
1097EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1098
1099/**
1100 * __spi_pump_messages - function which processes spi message queue
1101 * @master: master to process queue for
1102 * @in_kthread: true if we are in the context of the message pump thread
1103 *
1104 * This function checks if there is any spi message in the queue that
1105 * needs processing and if so call out to the driver to initialize hardware
1106 * and transfer each message.
1107 *
1108 * Note that it is called both from the kthread itself and also from
1109 * inside spi_sync(); the queue extraction handling at the top of the
1110 * function should deal with this safely.
1111 */
1112static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
1113{
1114 unsigned long flags;
1115 bool was_busy = false;
1116 int ret;
1117
1118 /* Lock queue */
1119 spin_lock_irqsave(&master->queue_lock, flags);
1120
1121 /* Make sure we are not already running a message */
1122 if (master->cur_msg) {
1123 spin_unlock_irqrestore(&master->queue_lock, flags);
1124 return;
1125 }
1126
1127 /* If another context is idling the device then defer */
1128 if (master->idling) {
1129 kthread_queue_work(&master->kworker, &master->pump_messages);
1130 spin_unlock_irqrestore(&master->queue_lock, flags);
1131 return;
1132 }
1133
1134 /* Check if the queue is idle */
1135 if (list_empty(&master->queue) || !master->running) {
1136 if (!master->busy) {
1137 spin_unlock_irqrestore(&master->queue_lock, flags);
1138 return;
1139 }
1140
1141 /* Only do teardown in the thread */
1142 if (!in_kthread) {
1143 kthread_queue_work(&master->kworker,
1144 &master->pump_messages);
1145 spin_unlock_irqrestore(&master->queue_lock, flags);
1146 return;
1147 }
1148
1149 master->busy = false;
1150 master->idling = true;
1151 spin_unlock_irqrestore(&master->queue_lock, flags);
1152
1153 kfree(master->dummy_rx);
1154 master->dummy_rx = NULL;
1155 kfree(master->dummy_tx);
1156 master->dummy_tx = NULL;
1157 if (master->unprepare_transfer_hardware &&
1158 master->unprepare_transfer_hardware(master))
1159 dev_err(&master->dev,
1160 "failed to unprepare transfer hardware\n");
1161 if (master->auto_runtime_pm) {
1162 pm_runtime_mark_last_busy(master->dev.parent);
1163 pm_runtime_put_autosuspend(master->dev.parent);
1164 }
1165 trace_spi_master_idle(master);
1166
1167 spin_lock_irqsave(&master->queue_lock, flags);
1168 master->idling = false;
1169 spin_unlock_irqrestore(&master->queue_lock, flags);
1170 return;
1171 }
1172
1173 /* Extract head of queue */
1174 master->cur_msg =
1175 list_first_entry(&master->queue, struct spi_message, queue);
1176
1177 list_del_init(&master->cur_msg->queue);
1178 if (master->busy)
1179 was_busy = true;
1180 else
1181 master->busy = true;
1182 spin_unlock_irqrestore(&master->queue_lock, flags);
1183
1184 mutex_lock(&master->io_mutex);
1185
1186 if (!was_busy && master->auto_runtime_pm) {
1187 ret = pm_runtime_get_sync(master->dev.parent);
1188 if (ret < 0) {
1189 dev_err(&master->dev, "Failed to power device: %d\n",
1190 ret);
1191 mutex_unlock(&master->io_mutex);
1192 return;
1193 }
1194 }
1195
1196 if (!was_busy)
1197 trace_spi_master_busy(master);
1198
1199 if (!was_busy && master->prepare_transfer_hardware) {
1200 ret = master->prepare_transfer_hardware(master);
1201 if (ret) {
1202 dev_err(&master->dev,
1203 "failed to prepare transfer hardware\n");
1204
1205 if (master->auto_runtime_pm)
1206 pm_runtime_put(master->dev.parent);
1207 mutex_unlock(&master->io_mutex);
1208 return;
1209 }
1210 }
1211
1212 trace_spi_message_start(master->cur_msg);
1213
1214 if (master->prepare_message) {
1215 ret = master->prepare_message(master, master->cur_msg);
1216 if (ret) {
1217 dev_err(&master->dev,
1218 "failed to prepare message: %d\n", ret);
1219 master->cur_msg->status = ret;
1220 spi_finalize_current_message(master);
1221 goto out;
1222 }
1223 master->cur_msg_prepared = true;
1224 }
1225
1226 ret = spi_map_msg(master, master->cur_msg);
1227 if (ret) {
1228 master->cur_msg->status = ret;
1229 spi_finalize_current_message(master);
1230 goto out;
1231 }
1232
1233 ret = master->transfer_one_message(master, master->cur_msg);
1234 if (ret) {
1235 dev_err(&master->dev,
1236 "failed to transfer one message from queue\n");
1237 goto out;
1238 }
1239
1240out:
1241 mutex_unlock(&master->io_mutex);
1242
1243 /* Prod the scheduler in case transfer_one() was busy waiting */
1244 if (!ret)
1245 cond_resched();
1246}
1247
1248/**
1249 * spi_pump_messages - kthread work function which processes spi message queue
1250 * @work: pointer to kthread work struct contained in the master struct
1251 */
1252static void spi_pump_messages(struct kthread_work *work)
1253{
1254 struct spi_master *master =
1255 container_of(work, struct spi_master, pump_messages);
1256
1257 __spi_pump_messages(master, true);
1258}
1259
1260static int spi_init_queue(struct spi_master *master)
1261{
1262 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1263
1264 master->running = false;
1265 master->busy = false;
1266
1267 kthread_init_worker(&master->kworker);
1268 master->kworker_task = kthread_run(kthread_worker_fn,
1269 &master->kworker, "%s",
1270 dev_name(&master->dev));
1271 if (IS_ERR(master->kworker_task)) {
1272 dev_err(&master->dev, "failed to create message pump task\n");
1273 return PTR_ERR(master->kworker_task);
1274 }
1275 kthread_init_work(&master->pump_messages, spi_pump_messages);
1276
1277 /*
1278 * Master config will indicate if this controller should run the
1279 * message pump with high (realtime) priority to reduce the transfer
1280 * latency on the bus by minimising the delay between a transfer
1281 * request and the scheduling of the message pump thread. Without this
1282 * setting the message pump thread will remain at default priority.
1283 */
1284 if (master->rt) {
1285 dev_info(&master->dev,
1286 "will run message pump with realtime priority\n");
1287 sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
1288 }
1289
1290 return 0;
1291}
1292
1293/**
1294 * spi_get_next_queued_message() - called by driver to check for queued
1295 * messages
1296 * @master: the master to check for queued messages
1297 *
1298 * If there are more messages in the queue, the next message is returned from
1299 * this call.
1300 *
1301 * Return: the next message in the queue, else NULL if the queue is empty.
1302 */
1303struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1304{
1305 struct spi_message *next;
1306 unsigned long flags;
1307
1308 /* get a pointer to the next message, if any */
1309 spin_lock_irqsave(&master->queue_lock, flags);
1310 next = list_first_entry_or_null(&master->queue, struct spi_message,
1311 queue);
1312 spin_unlock_irqrestore(&master->queue_lock, flags);
1313
1314 return next;
1315}
1316EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1317
1318/**
1319 * spi_finalize_current_message() - the current message is complete
1320 * @master: the master to return the message to
1321 *
1322 * Called by the driver to notify the core that the message in the front of the
1323 * queue is complete and can be removed from the queue.
1324 */
1325void spi_finalize_current_message(struct spi_master *master)
1326{
1327 struct spi_message *mesg;
1328 unsigned long flags;
1329 int ret;
1330
1331 spin_lock_irqsave(&master->queue_lock, flags);
1332 mesg = master->cur_msg;
1333 spin_unlock_irqrestore(&master->queue_lock, flags);
1334
1335 spi_unmap_msg(master, mesg);
1336
1337 if (master->cur_msg_prepared && master->unprepare_message) {
1338 ret = master->unprepare_message(master, mesg);
1339 if (ret) {
1340 dev_err(&master->dev,
1341 "failed to unprepare message: %d\n", ret);
1342 }
1343 }
1344
1345 spin_lock_irqsave(&master->queue_lock, flags);
1346 master->cur_msg = NULL;
1347 master->cur_msg_prepared = false;
1348 kthread_queue_work(&master->kworker, &master->pump_messages);
1349 spin_unlock_irqrestore(&master->queue_lock, flags);
1350
1351 trace_spi_message_done(mesg);
1352
1353 mesg->state = NULL;
1354 if (mesg->complete)
1355 mesg->complete(mesg->context);
1356}
1357EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1358
1359static int spi_start_queue(struct spi_master *master)
1360{
1361 unsigned long flags;
1362
1363 spin_lock_irqsave(&master->queue_lock, flags);
1364
1365 if (master->running || master->busy) {
1366 spin_unlock_irqrestore(&master->queue_lock, flags);
1367 return -EBUSY;
1368 }
1369
1370 master->running = true;
1371 master->cur_msg = NULL;
1372 spin_unlock_irqrestore(&master->queue_lock, flags);
1373
1374 kthread_queue_work(&master->kworker, &master->pump_messages);
1375
1376 return 0;
1377}
1378
1379static int spi_stop_queue(struct spi_master *master)
1380{
1381 unsigned long flags;
1382 unsigned limit = 500;
1383 int ret = 0;
1384
1385 spin_lock_irqsave(&master->queue_lock, flags);
1386
1387 /*
1388 * This is a bit lame, but is optimized for the common execution path.
1389 * A wait_queue on the master->busy could be used, but then the common
1390 * execution path (pump_messages) would be required to call wake_up or
1391 * friends on every SPI message. Do this instead.
1392 */
1393 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1394 spin_unlock_irqrestore(&master->queue_lock, flags);
1395 usleep_range(10000, 11000);
1396 spin_lock_irqsave(&master->queue_lock, flags);
1397 }
1398
1399 if (!list_empty(&master->queue) || master->busy)
1400 ret = -EBUSY;
1401 else
1402 master->running = false;
1403
1404 spin_unlock_irqrestore(&master->queue_lock, flags);
1405
1406 if (ret) {
1407 dev_warn(&master->dev,
1408 "could not stop message queue\n");
1409 return ret;
1410 }
1411 return ret;
1412}
1413
1414static int spi_destroy_queue(struct spi_master *master)
1415{
1416 int ret;
1417
1418 ret = spi_stop_queue(master);
1419
1420 /*
1421 * kthread_flush_worker will block until all work is done.
1422 * If the reason that stop_queue timed out is that the work will never
1423 * finish, then it does no good to call flush/stop thread, so
1424 * return anyway.
1425 */
1426 if (ret) {
1427 dev_err(&master->dev, "problem destroying queue\n");
1428 return ret;
1429 }
1430
1431 kthread_flush_worker(&master->kworker);
1432 kthread_stop(master->kworker_task);
1433
1434 return 0;
1435}
1436
1437static int __spi_queued_transfer(struct spi_device *spi,
1438 struct spi_message *msg,
1439 bool need_pump)
1440{
1441 struct spi_master *master = spi->master;
1442 unsigned long flags;
1443
1444 spin_lock_irqsave(&master->queue_lock, flags);
1445
1446 if (!master->running) {
1447 spin_unlock_irqrestore(&master->queue_lock, flags);
1448 return -ESHUTDOWN;
1449 }
1450 msg->actual_length = 0;
1451 msg->status = -EINPROGRESS;
1452
1453 list_add_tail(&msg->queue, &master->queue);
1454 if (!master->busy && need_pump)
1455 kthread_queue_work(&master->kworker, &master->pump_messages);
1456
1457 spin_unlock_irqrestore(&master->queue_lock, flags);
1458 return 0;
1459}
1460
1461/**
1462 * spi_queued_transfer - transfer function for queued transfers
1463 * @spi: spi device which is requesting transfer
1464 * @msg: spi message which is to handled is queued to driver queue
1465 *
1466 * Return: zero on success, else a negative error code.
1467 */
1468static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1469{
1470 return __spi_queued_transfer(spi, msg, true);
1471}
1472
1473static int spi_master_initialize_queue(struct spi_master *master)
1474{
1475 int ret;
1476
1477 master->transfer = spi_queued_transfer;
1478 if (!master->transfer_one_message)
1479 master->transfer_one_message = spi_transfer_one_message;
1480
1481 /* Initialize and start queue */
1482 ret = spi_init_queue(master);
1483 if (ret) {
1484 dev_err(&master->dev, "problem initializing queue\n");
1485 goto err_init_queue;
1486 }
1487 master->queued = true;
1488 ret = spi_start_queue(master);
1489 if (ret) {
1490 dev_err(&master->dev, "problem starting queue\n");
1491 goto err_start_queue;
1492 }
1493
1494 return 0;
1495
1496err_start_queue:
1497 spi_destroy_queue(master);
1498err_init_queue:
1499 return ret;
1500}
1501
1502/*-------------------------------------------------------------------------*/
1503
1504#if defined(CONFIG_OF)
1505static struct spi_device *
1506of_register_spi_device(struct spi_master *master, struct device_node *nc)
1507{
1508 struct spi_device *spi;
1509 int rc;
1510 u32 value;
1511
1512 /* Alloc an spi_device */
1513 spi = spi_alloc_device(master);
1514 if (!spi) {
1515 dev_err(&master->dev, "spi_device alloc error for %s\n",
1516 nc->full_name);
1517 rc = -ENOMEM;
1518 goto err_out;
1519 }
1520
1521 /* Select device driver */
1522 rc = of_modalias_node(nc, spi->modalias,
1523 sizeof(spi->modalias));
1524 if (rc < 0) {
1525 dev_err(&master->dev, "cannot find modalias for %s\n",
1526 nc->full_name);
1527 goto err_out;
1528 }
1529
1530 /* Device address */
1531 rc = of_property_read_u32(nc, "reg", &value);
1532 if (rc) {
1533 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1534 nc->full_name, rc);
1535 goto err_out;
1536 }
1537 spi->chip_select = value;
1538
1539 /* Mode (clock phase/polarity/etc.) */
1540 if (of_find_property(nc, "spi-cpha", NULL))
1541 spi->mode |= SPI_CPHA;
1542 if (of_find_property(nc, "spi-cpol", NULL))
1543 spi->mode |= SPI_CPOL;
1544 if (of_find_property(nc, "spi-cs-high", NULL))
1545 spi->mode |= SPI_CS_HIGH;
1546 if (of_find_property(nc, "spi-3wire", NULL))
1547 spi->mode |= SPI_3WIRE;
1548 if (of_find_property(nc, "spi-lsb-first", NULL))
1549 spi->mode |= SPI_LSB_FIRST;
1550
1551 /* Device DUAL/QUAD mode */
1552 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1553 switch (value) {
1554 case 1:
1555 break;
1556 case 2:
1557 spi->mode |= SPI_TX_DUAL;
1558 break;
1559 case 4:
1560 spi->mode |= SPI_TX_QUAD;
1561 break;
1562 default:
1563 dev_warn(&master->dev,
1564 "spi-tx-bus-width %d not supported\n",
1565 value);
1566 break;
1567 }
1568 }
1569
1570 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1571 switch (value) {
1572 case 1:
1573 break;
1574 case 2:
1575 spi->mode |= SPI_RX_DUAL;
1576 break;
1577 case 4:
1578 spi->mode |= SPI_RX_QUAD;
1579 break;
1580 default:
1581 dev_warn(&master->dev,
1582 "spi-rx-bus-width %d not supported\n",
1583 value);
1584 break;
1585 }
1586 }
1587
1588 /* Device speed */
1589 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1590 if (rc) {
1591 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1592 nc->full_name, rc);
1593 goto err_out;
1594 }
1595 spi->max_speed_hz = value;
1596
1597 /* Store a pointer to the node in the device structure */
1598 of_node_get(nc);
1599 spi->dev.of_node = nc;
1600
1601 /* Register the new device */
1602 rc = spi_add_device(spi);
1603 if (rc) {
1604 dev_err(&master->dev, "spi_device register error %s\n",
1605 nc->full_name);
1606 goto err_out;
1607 }
1608
1609 return spi;
1610
1611err_out:
1612 spi_dev_put(spi);
1613 return ERR_PTR(rc);
1614}
1615
1616/**
1617 * of_register_spi_devices() - Register child devices onto the SPI bus
1618 * @master: Pointer to spi_master device
1619 *
1620 * Registers an spi_device for each child node of master node which has a 'reg'
1621 * property.
1622 */
1623static void of_register_spi_devices(struct spi_master *master)
1624{
1625 struct spi_device *spi;
1626 struct device_node *nc;
1627
1628 if (!master->dev.of_node)
1629 return;
1630
1631 for_each_available_child_of_node(master->dev.of_node, nc) {
1632 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1633 continue;
1634 spi = of_register_spi_device(master, nc);
1635 if (IS_ERR(spi)) {
1636 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
1637 nc->full_name);
1638 of_node_clear_flag(nc, OF_POPULATED);
1639 }
1640 }
1641}
1642#else
1643static void of_register_spi_devices(struct spi_master *master) { }
1644#endif
1645
1646#ifdef CONFIG_ACPI
1647static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1648{
1649 struct spi_device *spi = data;
1650 struct spi_master *master = spi->master;
1651
1652 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1653 struct acpi_resource_spi_serialbus *sb;
1654
1655 sb = &ares->data.spi_serial_bus;
1656 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1657 /*
1658 * ACPI DeviceSelection numbering is handled by the
1659 * host controller driver in Windows and can vary
1660 * from driver to driver. In Linux we always expect
1661 * 0 .. max - 1 so we need to ask the driver to
1662 * translate between the two schemes.
1663 */
1664 if (master->fw_translate_cs) {
1665 int cs = master->fw_translate_cs(master,
1666 sb->device_selection);
1667 if (cs < 0)
1668 return cs;
1669 spi->chip_select = cs;
1670 } else {
1671 spi->chip_select = sb->device_selection;
1672 }
1673
1674 spi->max_speed_hz = sb->connection_speed;
1675
1676 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1677 spi->mode |= SPI_CPHA;
1678 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1679 spi->mode |= SPI_CPOL;
1680 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1681 spi->mode |= SPI_CS_HIGH;
1682 }
1683 } else if (spi->irq < 0) {
1684 struct resource r;
1685
1686 if (acpi_dev_resource_interrupt(ares, 0, &r))
1687 spi->irq = r.start;
1688 }
1689
1690 /* Always tell the ACPI core to skip this resource */
1691 return 1;
1692}
1693
1694static acpi_status acpi_register_spi_device(struct spi_master *master,
1695 struct acpi_device *adev)
1696{
1697 struct list_head resource_list;
1698 struct spi_device *spi;
1699 int ret;
1700
1701 if (acpi_bus_get_status(adev) || !adev->status.present ||
1702 acpi_device_enumerated(adev))
1703 return AE_OK;
1704
1705 spi = spi_alloc_device(master);
1706 if (!spi) {
1707 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1708 dev_name(&adev->dev));
1709 return AE_NO_MEMORY;
1710 }
1711
1712 ACPI_COMPANION_SET(&spi->dev, adev);
1713 spi->irq = -1;
1714
1715 INIT_LIST_HEAD(&resource_list);
1716 ret = acpi_dev_get_resources(adev, &resource_list,
1717 acpi_spi_add_resource, spi);
1718 acpi_dev_free_resource_list(&resource_list);
1719
1720 if (ret < 0 || !spi->max_speed_hz) {
1721 spi_dev_put(spi);
1722 return AE_OK;
1723 }
1724
1725 if (spi->irq < 0)
1726 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1727
1728 acpi_device_set_enumerated(adev);
1729
1730 adev->power.flags.ignore_parent = true;
1731 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
1732 if (spi_add_device(spi)) {
1733 adev->power.flags.ignore_parent = false;
1734 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1735 dev_name(&adev->dev));
1736 spi_dev_put(spi);
1737 }
1738
1739 return AE_OK;
1740}
1741
1742static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1743 void *data, void **return_value)
1744{
1745 struct spi_master *master = data;
1746 struct acpi_device *adev;
1747
1748 if (acpi_bus_get_device(handle, &adev))
1749 return AE_OK;
1750
1751 return acpi_register_spi_device(master, adev);
1752}
1753
1754static void acpi_register_spi_devices(struct spi_master *master)
1755{
1756 acpi_status status;
1757 acpi_handle handle;
1758
1759 handle = ACPI_HANDLE(master->dev.parent);
1760 if (!handle)
1761 return;
1762
1763 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1764 acpi_spi_add_device, NULL,
1765 master, NULL);
1766 if (ACPI_FAILURE(status))
1767 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1768}
1769#else
1770static inline void acpi_register_spi_devices(struct spi_master *master) {}
1771#endif /* CONFIG_ACPI */
1772
1773static void spi_master_release(struct device *dev)
1774{
1775 struct spi_master *master;
1776
1777 master = container_of(dev, struct spi_master, dev);
1778 kfree(master);
1779}
1780
1781static struct class spi_master_class = {
1782 .name = "spi_master",
1783 .owner = THIS_MODULE,
1784 .dev_release = spi_master_release,
1785 .dev_groups = spi_master_groups,
1786};
1787
1788
1789/**
1790 * spi_alloc_master - allocate SPI master controller
1791 * @dev: the controller, possibly using the platform_bus
1792 * @size: how much zeroed driver-private data to allocate; the pointer to this
1793 * memory is in the driver_data field of the returned device,
1794 * accessible with spi_master_get_devdata().
1795 * Context: can sleep
1796 *
1797 * This call is used only by SPI master controller drivers, which are the
1798 * only ones directly touching chip registers. It's how they allocate
1799 * an spi_master structure, prior to calling spi_register_master().
1800 *
1801 * This must be called from context that can sleep.
1802 *
1803 * The caller is responsible for assigning the bus number and initializing
1804 * the master's methods before calling spi_register_master(); and (after errors
1805 * adding the device) calling spi_master_put() to prevent a memory leak.
1806 *
1807 * Return: the SPI master structure on success, else NULL.
1808 */
1809struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
1810{
1811 struct spi_master *master;
1812
1813 if (!dev)
1814 return NULL;
1815
1816 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
1817 if (!master)
1818 return NULL;
1819
1820 device_initialize(&master->dev);
1821 master->bus_num = -1;
1822 master->num_chipselect = 1;
1823 master->dev.class = &spi_master_class;
1824 master->dev.parent = dev;
1825 pm_suspend_ignore_children(&master->dev, true);
1826 spi_master_set_devdata(master, &master[1]);
1827
1828 return master;
1829}
1830EXPORT_SYMBOL_GPL(spi_alloc_master);
1831
1832#ifdef CONFIG_OF
1833static int of_spi_register_master(struct spi_master *master)
1834{
1835 int nb, i, *cs;
1836 struct device_node *np = master->dev.of_node;
1837
1838 if (!np)
1839 return 0;
1840
1841 nb = of_gpio_named_count(np, "cs-gpios");
1842 master->num_chipselect = max_t(int, nb, master->num_chipselect);
1843
1844 /* Return error only for an incorrectly formed cs-gpios property */
1845 if (nb == 0 || nb == -ENOENT)
1846 return 0;
1847 else if (nb < 0)
1848 return nb;
1849
1850 cs = devm_kzalloc(&master->dev,
1851 sizeof(int) * master->num_chipselect,
1852 GFP_KERNEL);
1853 master->cs_gpios = cs;
1854
1855 if (!master->cs_gpios)
1856 return -ENOMEM;
1857
1858 for (i = 0; i < master->num_chipselect; i++)
1859 cs[i] = -ENOENT;
1860
1861 for (i = 0; i < nb; i++)
1862 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1863
1864 return 0;
1865}
1866#else
1867static int of_spi_register_master(struct spi_master *master)
1868{
1869 return 0;
1870}
1871#endif
1872
1873/**
1874 * spi_register_master - register SPI master controller
1875 * @master: initialized master, originally from spi_alloc_master()
1876 * Context: can sleep
1877 *
1878 * SPI master controllers connect to their drivers using some non-SPI bus,
1879 * such as the platform bus. The final stage of probe() in that code
1880 * includes calling spi_register_master() to hook up to this SPI bus glue.
1881 *
1882 * SPI controllers use board specific (often SOC specific) bus numbers,
1883 * and board-specific addressing for SPI devices combines those numbers
1884 * with chip select numbers. Since SPI does not directly support dynamic
1885 * device identification, boards need configuration tables telling which
1886 * chip is at which address.
1887 *
1888 * This must be called from context that can sleep. It returns zero on
1889 * success, else a negative error code (dropping the master's refcount).
1890 * After a successful return, the caller is responsible for calling
1891 * spi_unregister_master().
1892 *
1893 * Return: zero on success, else a negative error code.
1894 */
1895int spi_register_master(struct spi_master *master)
1896{
1897 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
1898 struct device *dev = master->dev.parent;
1899 struct boardinfo *bi;
1900 int status = -ENODEV;
1901 int dynamic = 0;
1902
1903 if (!dev)
1904 return -ENODEV;
1905
1906 status = of_spi_register_master(master);
1907 if (status)
1908 return status;
1909
1910 /* even if it's just one always-selected device, there must
1911 * be at least one chipselect
1912 */
1913 if (master->num_chipselect == 0)
1914 return -EINVAL;
1915
1916 if ((master->bus_num < 0) && master->dev.of_node)
1917 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1918
1919 /* convention: dynamically assigned bus IDs count down from the max */
1920 if (master->bus_num < 0) {
1921 /* FIXME switch to an IDR based scheme, something like
1922 * I2C now uses, so we can't run out of "dynamic" IDs
1923 */
1924 master->bus_num = atomic_dec_return(&dyn_bus_id);
1925 dynamic = 1;
1926 }
1927
1928 INIT_LIST_HEAD(&master->queue);
1929 spin_lock_init(&master->queue_lock);
1930 spin_lock_init(&master->bus_lock_spinlock);
1931 mutex_init(&master->bus_lock_mutex);
1932 mutex_init(&master->io_mutex);
1933 master->bus_lock_flag = 0;
1934 init_completion(&master->xfer_completion);
1935 if (!master->max_dma_len)
1936 master->max_dma_len = INT_MAX;
1937
1938 /* register the device, then userspace will see it.
1939 * registration fails if the bus ID is in use.
1940 */
1941 dev_set_name(&master->dev, "spi%u", master->bus_num);
1942 status = device_add(&master->dev);
1943 if (status < 0)
1944 goto done;
1945 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
1946 dynamic ? " (dynamic)" : "");
1947
1948 /* If we're using a queued driver, start the queue */
1949 if (master->transfer)
1950 dev_info(dev, "master is unqueued, this is deprecated\n");
1951 else {
1952 status = spi_master_initialize_queue(master);
1953 if (status) {
1954 device_del(&master->dev);
1955 goto done;
1956 }
1957 }
1958 /* add statistics */
1959 spin_lock_init(&master->statistics.lock);
1960
1961 mutex_lock(&board_lock);
1962 list_add_tail(&master->list, &spi_master_list);
1963 list_for_each_entry(bi, &board_list, list)
1964 spi_match_master_to_boardinfo(master, &bi->board_info);
1965 mutex_unlock(&board_lock);
1966
1967 /* Register devices from the device tree and ACPI */
1968 of_register_spi_devices(master);
1969 acpi_register_spi_devices(master);
1970done:
1971 return status;
1972}
1973EXPORT_SYMBOL_GPL(spi_register_master);
1974
1975static void devm_spi_unregister(struct device *dev, void *res)
1976{
1977 spi_unregister_master(*(struct spi_master **)res);
1978}
1979
1980/**
1981 * dev_spi_register_master - register managed SPI master controller
1982 * @dev: device managing SPI master
1983 * @master: initialized master, originally from spi_alloc_master()
1984 * Context: can sleep
1985 *
1986 * Register a SPI device as with spi_register_master() which will
1987 * automatically be unregister
1988 *
1989 * Return: zero on success, else a negative error code.
1990 */
1991int devm_spi_register_master(struct device *dev, struct spi_master *master)
1992{
1993 struct spi_master **ptr;
1994 int ret;
1995
1996 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1997 if (!ptr)
1998 return -ENOMEM;
1999
2000 ret = spi_register_master(master);
2001 if (!ret) {
2002 *ptr = master;
2003 devres_add(dev, ptr);
2004 } else {
2005 devres_free(ptr);
2006 }
2007
2008 return ret;
2009}
2010EXPORT_SYMBOL_GPL(devm_spi_register_master);
2011
2012static int __unregister(struct device *dev, void *null)
2013{
2014 spi_unregister_device(to_spi_device(dev));
2015 return 0;
2016}
2017
2018/**
2019 * spi_unregister_master - unregister SPI master controller
2020 * @master: the master being unregistered
2021 * Context: can sleep
2022 *
2023 * This call is used only by SPI master controller drivers, which are the
2024 * only ones directly touching chip registers.
2025 *
2026 * This must be called from context that can sleep.
2027 */
2028void spi_unregister_master(struct spi_master *master)
2029{
2030 int dummy;
2031
2032 if (master->queued) {
2033 if (spi_destroy_queue(master))
2034 dev_err(&master->dev, "queue remove failed\n");
2035 }
2036
2037 mutex_lock(&board_lock);
2038 list_del(&master->list);
2039 mutex_unlock(&board_lock);
2040
2041 dummy = device_for_each_child(&master->dev, NULL, __unregister);
2042 device_unregister(&master->dev);
2043}
2044EXPORT_SYMBOL_GPL(spi_unregister_master);
2045
2046int spi_master_suspend(struct spi_master *master)
2047{
2048 int ret;
2049
2050 /* Basically no-ops for non-queued masters */
2051 if (!master->queued)
2052 return 0;
2053
2054 ret = spi_stop_queue(master);
2055 if (ret)
2056 dev_err(&master->dev, "queue stop failed\n");
2057
2058 return ret;
2059}
2060EXPORT_SYMBOL_GPL(spi_master_suspend);
2061
2062int spi_master_resume(struct spi_master *master)
2063{
2064 int ret;
2065
2066 if (!master->queued)
2067 return 0;
2068
2069 ret = spi_start_queue(master);
2070 if (ret)
2071 dev_err(&master->dev, "queue restart failed\n");
2072
2073 return ret;
2074}
2075EXPORT_SYMBOL_GPL(spi_master_resume);
2076
2077static int __spi_master_match(struct device *dev, const void *data)
2078{
2079 struct spi_master *m;
2080 const u16 *bus_num = data;
2081
2082 m = container_of(dev, struct spi_master, dev);
2083 return m->bus_num == *bus_num;
2084}
2085
2086/**
2087 * spi_busnum_to_master - look up master associated with bus_num
2088 * @bus_num: the master's bus number
2089 * Context: can sleep
2090 *
2091 * This call may be used with devices that are registered after
2092 * arch init time. It returns a refcounted pointer to the relevant
2093 * spi_master (which the caller must release), or NULL if there is
2094 * no such master registered.
2095 *
2096 * Return: the SPI master structure on success, else NULL.
2097 */
2098struct spi_master *spi_busnum_to_master(u16 bus_num)
2099{
2100 struct device *dev;
2101 struct spi_master *master = NULL;
2102
2103 dev = class_find_device(&spi_master_class, NULL, &bus_num,
2104 __spi_master_match);
2105 if (dev)
2106 master = container_of(dev, struct spi_master, dev);
2107 /* reference got in class_find_device */
2108 return master;
2109}
2110EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2111
2112/*-------------------------------------------------------------------------*/
2113
2114/* Core methods for SPI resource management */
2115
2116/**
2117 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2118 * during the processing of a spi_message while using
2119 * spi_transfer_one
2120 * @spi: the spi device for which we allocate memory
2121 * @release: the release code to execute for this resource
2122 * @size: size to alloc and return
2123 * @gfp: GFP allocation flags
2124 *
2125 * Return: the pointer to the allocated data
2126 *
2127 * This may get enhanced in the future to allocate from a memory pool
2128 * of the @spi_device or @spi_master to avoid repeated allocations.
2129 */
2130void *spi_res_alloc(struct spi_device *spi,
2131 spi_res_release_t release,
2132 size_t size, gfp_t gfp)
2133{
2134 struct spi_res *sres;
2135
2136 sres = kzalloc(sizeof(*sres) + size, gfp);
2137 if (!sres)
2138 return NULL;
2139
2140 INIT_LIST_HEAD(&sres->entry);
2141 sres->release = release;
2142
2143 return sres->data;
2144}
2145EXPORT_SYMBOL_GPL(spi_res_alloc);
2146
2147/**
2148 * spi_res_free - free an spi resource
2149 * @res: pointer to the custom data of a resource
2150 *
2151 */
2152void spi_res_free(void *res)
2153{
2154 struct spi_res *sres = container_of(res, struct spi_res, data);
2155
2156 if (!res)
2157 return;
2158
2159 WARN_ON(!list_empty(&sres->entry));
2160 kfree(sres);
2161}
2162EXPORT_SYMBOL_GPL(spi_res_free);
2163
2164/**
2165 * spi_res_add - add a spi_res to the spi_message
2166 * @message: the spi message
2167 * @res: the spi_resource
2168 */
2169void spi_res_add(struct spi_message *message, void *res)
2170{
2171 struct spi_res *sres = container_of(res, struct spi_res, data);
2172
2173 WARN_ON(!list_empty(&sres->entry));
2174 list_add_tail(&sres->entry, &message->resources);
2175}
2176EXPORT_SYMBOL_GPL(spi_res_add);
2177
2178/**
2179 * spi_res_release - release all spi resources for this message
2180 * @master: the @spi_master
2181 * @message: the @spi_message
2182 */
2183void spi_res_release(struct spi_master *master,
2184 struct spi_message *message)
2185{
2186 struct spi_res *res;
2187
2188 while (!list_empty(&message->resources)) {
2189 res = list_last_entry(&message->resources,
2190 struct spi_res, entry);
2191
2192 if (res->release)
2193 res->release(master, message, res->data);
2194
2195 list_del(&res->entry);
2196
2197 kfree(res);
2198 }
2199}
2200EXPORT_SYMBOL_GPL(spi_res_release);
2201
2202/*-------------------------------------------------------------------------*/
2203
2204/* Core methods for spi_message alterations */
2205
2206static void __spi_replace_transfers_release(struct spi_master *master,
2207 struct spi_message *msg,
2208 void *res)
2209{
2210 struct spi_replaced_transfers *rxfer = res;
2211 size_t i;
2212
2213 /* call extra callback if requested */
2214 if (rxfer->release)
2215 rxfer->release(master, msg, res);
2216
2217 /* insert replaced transfers back into the message */
2218 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2219
2220 /* remove the formerly inserted entries */
2221 for (i = 0; i < rxfer->inserted; i++)
2222 list_del(&rxfer->inserted_transfers[i].transfer_list);
2223}
2224
2225/**
2226 * spi_replace_transfers - replace transfers with several transfers
2227 * and register change with spi_message.resources
2228 * @msg: the spi_message we work upon
2229 * @xfer_first: the first spi_transfer we want to replace
2230 * @remove: number of transfers to remove
2231 * @insert: the number of transfers we want to insert instead
2232 * @release: extra release code necessary in some circumstances
2233 * @extradatasize: extra data to allocate (with alignment guarantees
2234 * of struct @spi_transfer)
2235 * @gfp: gfp flags
2236 *
2237 * Returns: pointer to @spi_replaced_transfers,
2238 * PTR_ERR(...) in case of errors.
2239 */
2240struct spi_replaced_transfers *spi_replace_transfers(
2241 struct spi_message *msg,
2242 struct spi_transfer *xfer_first,
2243 size_t remove,
2244 size_t insert,
2245 spi_replaced_release_t release,
2246 size_t extradatasize,
2247 gfp_t gfp)
2248{
2249 struct spi_replaced_transfers *rxfer;
2250 struct spi_transfer *xfer;
2251 size_t i;
2252
2253 /* allocate the structure using spi_res */
2254 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2255 insert * sizeof(struct spi_transfer)
2256 + sizeof(struct spi_replaced_transfers)
2257 + extradatasize,
2258 gfp);
2259 if (!rxfer)
2260 return ERR_PTR(-ENOMEM);
2261
2262 /* the release code to invoke before running the generic release */
2263 rxfer->release = release;
2264
2265 /* assign extradata */
2266 if (extradatasize)
2267 rxfer->extradata =
2268 &rxfer->inserted_transfers[insert];
2269
2270 /* init the replaced_transfers list */
2271 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2272
2273 /* assign the list_entry after which we should reinsert
2274 * the @replaced_transfers - it may be spi_message.messages!
2275 */
2276 rxfer->replaced_after = xfer_first->transfer_list.prev;
2277
2278 /* remove the requested number of transfers */
2279 for (i = 0; i < remove; i++) {
2280 /* if the entry after replaced_after it is msg->transfers
2281 * then we have been requested to remove more transfers
2282 * than are in the list
2283 */
2284 if (rxfer->replaced_after->next == &msg->transfers) {
2285 dev_err(&msg->spi->dev,
2286 "requested to remove more spi_transfers than are available\n");
2287 /* insert replaced transfers back into the message */
2288 list_splice(&rxfer->replaced_transfers,
2289 rxfer->replaced_after);
2290
2291 /* free the spi_replace_transfer structure */
2292 spi_res_free(rxfer);
2293
2294 /* and return with an error */
2295 return ERR_PTR(-EINVAL);
2296 }
2297
2298 /* remove the entry after replaced_after from list of
2299 * transfers and add it to list of replaced_transfers
2300 */
2301 list_move_tail(rxfer->replaced_after->next,
2302 &rxfer->replaced_transfers);
2303 }
2304
2305 /* create copy of the given xfer with identical settings
2306 * based on the first transfer to get removed
2307 */
2308 for (i = 0; i < insert; i++) {
2309 /* we need to run in reverse order */
2310 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2311
2312 /* copy all spi_transfer data */
2313 memcpy(xfer, xfer_first, sizeof(*xfer));
2314
2315 /* add to list */
2316 list_add(&xfer->transfer_list, rxfer->replaced_after);
2317
2318 /* clear cs_change and delay_usecs for all but the last */
2319 if (i) {
2320 xfer->cs_change = false;
2321 xfer->delay_usecs = 0;
2322 }
2323 }
2324
2325 /* set up inserted */
2326 rxfer->inserted = insert;
2327
2328 /* and register it with spi_res/spi_message */
2329 spi_res_add(msg, rxfer);
2330
2331 return rxfer;
2332}
2333EXPORT_SYMBOL_GPL(spi_replace_transfers);
2334
2335static int __spi_split_transfer_maxsize(struct spi_master *master,
2336 struct spi_message *msg,
2337 struct spi_transfer **xferp,
2338 size_t maxsize,
2339 gfp_t gfp)
2340{
2341 struct spi_transfer *xfer = *xferp, *xfers;
2342 struct spi_replaced_transfers *srt;
2343 size_t offset;
2344 size_t count, i;
2345
2346 /* warn once about this fact that we are splitting a transfer */
2347 dev_warn_once(&msg->spi->dev,
2348 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
2349 xfer->len, maxsize);
2350
2351 /* calculate how many we have to replace */
2352 count = DIV_ROUND_UP(xfer->len, maxsize);
2353
2354 /* create replacement */
2355 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
2356 if (IS_ERR(srt))
2357 return PTR_ERR(srt);
2358 xfers = srt->inserted_transfers;
2359
2360 /* now handle each of those newly inserted spi_transfers
2361 * note that the replacements spi_transfers all are preset
2362 * to the same values as *xferp, so tx_buf, rx_buf and len
2363 * are all identical (as well as most others)
2364 * so we just have to fix up len and the pointers.
2365 *
2366 * this also includes support for the depreciated
2367 * spi_message.is_dma_mapped interface
2368 */
2369
2370 /* the first transfer just needs the length modified, so we
2371 * run it outside the loop
2372 */
2373 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
2374
2375 /* all the others need rx_buf/tx_buf also set */
2376 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2377 /* update rx_buf, tx_buf and dma */
2378 if (xfers[i].rx_buf)
2379 xfers[i].rx_buf += offset;
2380 if (xfers[i].rx_dma)
2381 xfers[i].rx_dma += offset;
2382 if (xfers[i].tx_buf)
2383 xfers[i].tx_buf += offset;
2384 if (xfers[i].tx_dma)
2385 xfers[i].tx_dma += offset;
2386
2387 /* update length */
2388 xfers[i].len = min(maxsize, xfers[i].len - offset);
2389 }
2390
2391 /* we set up xferp to the last entry we have inserted,
2392 * so that we skip those already split transfers
2393 */
2394 *xferp = &xfers[count - 1];
2395
2396 /* increment statistics counters */
2397 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2398 transfers_split_maxsize);
2399 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2400 transfers_split_maxsize);
2401
2402 return 0;
2403}
2404
2405/**
2406 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2407 * when an individual transfer exceeds a
2408 * certain size
2409 * @master: the @spi_master for this transfer
2410 * @msg: the @spi_message to transform
2411 * @maxsize: the maximum when to apply this
2412 * @gfp: GFP allocation flags
2413 *
2414 * Return: status of transformation
2415 */
2416int spi_split_transfers_maxsize(struct spi_master *master,
2417 struct spi_message *msg,
2418 size_t maxsize,
2419 gfp_t gfp)
2420{
2421 struct spi_transfer *xfer;
2422 int ret;
2423
2424 /* iterate over the transfer_list,
2425 * but note that xfer is advanced to the last transfer inserted
2426 * to avoid checking sizes again unnecessarily (also xfer does
2427 * potentiall belong to a different list by the time the
2428 * replacement has happened
2429 */
2430 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2431 if (xfer->len > maxsize) {
2432 ret = __spi_split_transfer_maxsize(
2433 master, msg, &xfer, maxsize, gfp);
2434 if (ret)
2435 return ret;
2436 }
2437 }
2438
2439 return 0;
2440}
2441EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2442
2443/*-------------------------------------------------------------------------*/
2444
2445/* Core methods for SPI master protocol drivers. Some of the
2446 * other core methods are currently defined as inline functions.
2447 */
2448
2449static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2450{
2451 if (master->bits_per_word_mask) {
2452 /* Only 32 bits fit in the mask */
2453 if (bits_per_word > 32)
2454 return -EINVAL;
2455 if (!(master->bits_per_word_mask &
2456 SPI_BPW_MASK(bits_per_word)))
2457 return -EINVAL;
2458 }
2459
2460 return 0;
2461}
2462
2463/**
2464 * spi_setup - setup SPI mode and clock rate
2465 * @spi: the device whose settings are being modified
2466 * Context: can sleep, and no requests are queued to the device
2467 *
2468 * SPI protocol drivers may need to update the transfer mode if the
2469 * device doesn't work with its default. They may likewise need
2470 * to update clock rates or word sizes from initial values. This function
2471 * changes those settings, and must be called from a context that can sleep.
2472 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2473 * effect the next time the device is selected and data is transferred to
2474 * or from it. When this function returns, the spi device is deselected.
2475 *
2476 * Note that this call will fail if the protocol driver specifies an option
2477 * that the underlying controller or its driver does not support. For
2478 * example, not all hardware supports wire transfers using nine bit words,
2479 * LSB-first wire encoding, or active-high chipselects.
2480 *
2481 * Return: zero on success, else a negative error code.
2482 */
2483int spi_setup(struct spi_device *spi)
2484{
2485 unsigned bad_bits, ugly_bits;
2486 int status;
2487
2488 /* check mode to prevent that DUAL and QUAD set at the same time
2489 */
2490 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2491 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2492 dev_err(&spi->dev,
2493 "setup: can not select dual and quad at the same time\n");
2494 return -EINVAL;
2495 }
2496 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2497 */
2498 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2499 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2500 return -EINVAL;
2501 /* help drivers fail *cleanly* when they need options
2502 * that aren't supported with their current master
2503 */
2504 bad_bits = spi->mode & ~spi->master->mode_bits;
2505 ugly_bits = bad_bits &
2506 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2507 if (ugly_bits) {
2508 dev_warn(&spi->dev,
2509 "setup: ignoring unsupported mode bits %x\n",
2510 ugly_bits);
2511 spi->mode &= ~ugly_bits;
2512 bad_bits &= ~ugly_bits;
2513 }
2514 if (bad_bits) {
2515 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
2516 bad_bits);
2517 return -EINVAL;
2518 }
2519
2520 if (!spi->bits_per_word)
2521 spi->bits_per_word = 8;
2522
2523 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2524 if (status)
2525 return status;
2526
2527 if (!spi->max_speed_hz)
2528 spi->max_speed_hz = spi->master->max_speed_hz;
2529
2530 if (spi->master->setup)
2531 status = spi->master->setup(spi);
2532
2533 spi_set_cs(spi, false);
2534
2535 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
2536 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2537 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2538 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2539 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2540 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2541 spi->bits_per_word, spi->max_speed_hz,
2542 status);
2543
2544 return status;
2545}
2546EXPORT_SYMBOL_GPL(spi_setup);
2547
2548static int __spi_validate(struct spi_device *spi, struct spi_message *message)
2549{
2550 struct spi_master *master = spi->master;
2551 struct spi_transfer *xfer;
2552 int w_size;
2553
2554 if (list_empty(&message->transfers))
2555 return -EINVAL;
2556
2557 /* Half-duplex links include original MicroWire, and ones with
2558 * only one data pin like SPI_3WIRE (switches direction) or where
2559 * either MOSI or MISO is missing. They can also be caused by
2560 * software limitations.
2561 */
2562 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2563 || (spi->mode & SPI_3WIRE)) {
2564 unsigned flags = master->flags;
2565
2566 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2567 if (xfer->rx_buf && xfer->tx_buf)
2568 return -EINVAL;
2569 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2570 return -EINVAL;
2571 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2572 return -EINVAL;
2573 }
2574 }
2575
2576 /**
2577 * Set transfer bits_per_word and max speed as spi device default if
2578 * it is not set for this transfer.
2579 * Set transfer tx_nbits and rx_nbits as single transfer default
2580 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
2581 */
2582 message->frame_length = 0;
2583 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2584 message->frame_length += xfer->len;
2585 if (!xfer->bits_per_word)
2586 xfer->bits_per_word = spi->bits_per_word;
2587
2588 if (!xfer->speed_hz)
2589 xfer->speed_hz = spi->max_speed_hz;
2590 if (!xfer->speed_hz)
2591 xfer->speed_hz = master->max_speed_hz;
2592
2593 if (master->max_speed_hz &&
2594 xfer->speed_hz > master->max_speed_hz)
2595 xfer->speed_hz = master->max_speed_hz;
2596
2597 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2598 return -EINVAL;
2599
2600 /*
2601 * SPI transfer length should be multiple of SPI word size
2602 * where SPI word size should be power-of-two multiple
2603 */
2604 if (xfer->bits_per_word <= 8)
2605 w_size = 1;
2606 else if (xfer->bits_per_word <= 16)
2607 w_size = 2;
2608 else
2609 w_size = 4;
2610
2611 /* No partial transfers accepted */
2612 if (xfer->len % w_size)
2613 return -EINVAL;
2614
2615 if (xfer->speed_hz && master->min_speed_hz &&
2616 xfer->speed_hz < master->min_speed_hz)
2617 return -EINVAL;
2618
2619 if (xfer->tx_buf && !xfer->tx_nbits)
2620 xfer->tx_nbits = SPI_NBITS_SINGLE;
2621 if (xfer->rx_buf && !xfer->rx_nbits)
2622 xfer->rx_nbits = SPI_NBITS_SINGLE;
2623 /* check transfer tx/rx_nbits:
2624 * 1. check the value matches one of single, dual and quad
2625 * 2. check tx/rx_nbits match the mode in spi_device
2626 */
2627 if (xfer->tx_buf) {
2628 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2629 xfer->tx_nbits != SPI_NBITS_DUAL &&
2630 xfer->tx_nbits != SPI_NBITS_QUAD)
2631 return -EINVAL;
2632 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2633 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2634 return -EINVAL;
2635 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2636 !(spi->mode & SPI_TX_QUAD))
2637 return -EINVAL;
2638 }
2639 /* check transfer rx_nbits */
2640 if (xfer->rx_buf) {
2641 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2642 xfer->rx_nbits != SPI_NBITS_DUAL &&
2643 xfer->rx_nbits != SPI_NBITS_QUAD)
2644 return -EINVAL;
2645 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2646 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2647 return -EINVAL;
2648 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2649 !(spi->mode & SPI_RX_QUAD))
2650 return -EINVAL;
2651 }
2652 }
2653
2654 message->status = -EINPROGRESS;
2655
2656 return 0;
2657}
2658
2659static int __spi_async(struct spi_device *spi, struct spi_message *message)
2660{
2661 struct spi_master *master = spi->master;
2662
2663 message->spi = spi;
2664
2665 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2666 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2667
2668 trace_spi_message_submit(message);
2669
2670 return master->transfer(spi, message);
2671}
2672
2673/**
2674 * spi_async - asynchronous SPI transfer
2675 * @spi: device with which data will be exchanged
2676 * @message: describes the data transfers, including completion callback
2677 * Context: any (irqs may be blocked, etc)
2678 *
2679 * This call may be used in_irq and other contexts which can't sleep,
2680 * as well as from task contexts which can sleep.
2681 *
2682 * The completion callback is invoked in a context which can't sleep.
2683 * Before that invocation, the value of message->status is undefined.
2684 * When the callback is issued, message->status holds either zero (to
2685 * indicate complete success) or a negative error code. After that
2686 * callback returns, the driver which issued the transfer request may
2687 * deallocate the associated memory; it's no longer in use by any SPI
2688 * core or controller driver code.
2689 *
2690 * Note that although all messages to a spi_device are handled in
2691 * FIFO order, messages may go to different devices in other orders.
2692 * Some device might be higher priority, or have various "hard" access
2693 * time requirements, for example.
2694 *
2695 * On detection of any fault during the transfer, processing of
2696 * the entire message is aborted, and the device is deselected.
2697 * Until returning from the associated message completion callback,
2698 * no other spi_message queued to that device will be processed.
2699 * (This rule applies equally to all the synchronous transfer calls,
2700 * which are wrappers around this core asynchronous primitive.)
2701 *
2702 * Return: zero on success, else a negative error code.
2703 */
2704int spi_async(struct spi_device *spi, struct spi_message *message)
2705{
2706 struct spi_master *master = spi->master;
2707 int ret;
2708 unsigned long flags;
2709
2710 ret = __spi_validate(spi, message);
2711 if (ret != 0)
2712 return ret;
2713
2714 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2715
2716 if (master->bus_lock_flag)
2717 ret = -EBUSY;
2718 else
2719 ret = __spi_async(spi, message);
2720
2721 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2722
2723 return ret;
2724}
2725EXPORT_SYMBOL_GPL(spi_async);
2726
2727/**
2728 * spi_async_locked - version of spi_async with exclusive bus usage
2729 * @spi: device with which data will be exchanged
2730 * @message: describes the data transfers, including completion callback
2731 * Context: any (irqs may be blocked, etc)
2732 *
2733 * This call may be used in_irq and other contexts which can't sleep,
2734 * as well as from task contexts which can sleep.
2735 *
2736 * The completion callback is invoked in a context which can't sleep.
2737 * Before that invocation, the value of message->status is undefined.
2738 * When the callback is issued, message->status holds either zero (to
2739 * indicate complete success) or a negative error code. After that
2740 * callback returns, the driver which issued the transfer request may
2741 * deallocate the associated memory; it's no longer in use by any SPI
2742 * core or controller driver code.
2743 *
2744 * Note that although all messages to a spi_device are handled in
2745 * FIFO order, messages may go to different devices in other orders.
2746 * Some device might be higher priority, or have various "hard" access
2747 * time requirements, for example.
2748 *
2749 * On detection of any fault during the transfer, processing of
2750 * the entire message is aborted, and the device is deselected.
2751 * Until returning from the associated message completion callback,
2752 * no other spi_message queued to that device will be processed.
2753 * (This rule applies equally to all the synchronous transfer calls,
2754 * which are wrappers around this core asynchronous primitive.)
2755 *
2756 * Return: zero on success, else a negative error code.
2757 */
2758int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2759{
2760 struct spi_master *master = spi->master;
2761 int ret;
2762 unsigned long flags;
2763
2764 ret = __spi_validate(spi, message);
2765 if (ret != 0)
2766 return ret;
2767
2768 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2769
2770 ret = __spi_async(spi, message);
2771
2772 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2773
2774 return ret;
2775
2776}
2777EXPORT_SYMBOL_GPL(spi_async_locked);
2778
2779
2780int spi_flash_read(struct spi_device *spi,
2781 struct spi_flash_read_message *msg)
2782
2783{
2784 struct spi_master *master = spi->master;
2785 struct device *rx_dev = NULL;
2786 int ret;
2787
2788 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2789 msg->addr_nbits == SPI_NBITS_DUAL) &&
2790 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2791 return -EINVAL;
2792 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2793 msg->addr_nbits == SPI_NBITS_QUAD) &&
2794 !(spi->mode & SPI_TX_QUAD))
2795 return -EINVAL;
2796 if (msg->data_nbits == SPI_NBITS_DUAL &&
2797 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2798 return -EINVAL;
2799 if (msg->data_nbits == SPI_NBITS_QUAD &&
2800 !(spi->mode & SPI_RX_QUAD))
2801 return -EINVAL;
2802
2803 if (master->auto_runtime_pm) {
2804 ret = pm_runtime_get_sync(master->dev.parent);
2805 if (ret < 0) {
2806 dev_err(&master->dev, "Failed to power device: %d\n",
2807 ret);
2808 return ret;
2809 }
2810 }
2811
2812 mutex_lock(&master->bus_lock_mutex);
2813 mutex_lock(&master->io_mutex);
2814 if (master->dma_rx) {
2815 rx_dev = master->dma_rx->device->dev;
2816 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2817 msg->buf, msg->len,
2818 DMA_FROM_DEVICE);
2819 if (!ret)
2820 msg->cur_msg_mapped = true;
2821 }
2822 ret = master->spi_flash_read(spi, msg);
2823 if (msg->cur_msg_mapped)
2824 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2825 DMA_FROM_DEVICE);
2826 mutex_unlock(&master->io_mutex);
2827 mutex_unlock(&master->bus_lock_mutex);
2828
2829 if (master->auto_runtime_pm)
2830 pm_runtime_put(master->dev.parent);
2831
2832 return ret;
2833}
2834EXPORT_SYMBOL_GPL(spi_flash_read);
2835
2836/*-------------------------------------------------------------------------*/
2837
2838/* Utility methods for SPI master protocol drivers, layered on
2839 * top of the core. Some other utility methods are defined as
2840 * inline functions.
2841 */
2842
2843static void spi_complete(void *arg)
2844{
2845 complete(arg);
2846}
2847
2848static int __spi_sync(struct spi_device *spi, struct spi_message *message)
2849{
2850 DECLARE_COMPLETION_ONSTACK(done);
2851 int status;
2852 struct spi_master *master = spi->master;
2853 unsigned long flags;
2854
2855 status = __spi_validate(spi, message);
2856 if (status != 0)
2857 return status;
2858
2859 message->complete = spi_complete;
2860 message->context = &done;
2861 message->spi = spi;
2862
2863 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2864 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2865
2866 /* If we're not using the legacy transfer method then we will
2867 * try to transfer in the calling context so special case.
2868 * This code would be less tricky if we could remove the
2869 * support for driver implemented message queues.
2870 */
2871 if (master->transfer == spi_queued_transfer) {
2872 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2873
2874 trace_spi_message_submit(message);
2875
2876 status = __spi_queued_transfer(spi, message, false);
2877
2878 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2879 } else {
2880 status = spi_async_locked(spi, message);
2881 }
2882
2883 if (status == 0) {
2884 /* Push out the messages in the calling context if we
2885 * can.
2886 */
2887 if (master->transfer == spi_queued_transfer) {
2888 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2889 spi_sync_immediate);
2890 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2891 spi_sync_immediate);
2892 __spi_pump_messages(master, false);
2893 }
2894
2895 wait_for_completion(&done);
2896 status = message->status;
2897 }
2898 message->context = NULL;
2899 return status;
2900}
2901
2902/**
2903 * spi_sync - blocking/synchronous SPI data transfers
2904 * @spi: device with which data will be exchanged
2905 * @message: describes the data transfers
2906 * Context: can sleep
2907 *
2908 * This call may only be used from a context that may sleep. The sleep
2909 * is non-interruptible, and has no timeout. Low-overhead controller
2910 * drivers may DMA directly into and out of the message buffers.
2911 *
2912 * Note that the SPI device's chip select is active during the message,
2913 * and then is normally disabled between messages. Drivers for some
2914 * frequently-used devices may want to minimize costs of selecting a chip,
2915 * by leaving it selected in anticipation that the next message will go
2916 * to the same chip. (That may increase power usage.)
2917 *
2918 * Also, the caller is guaranteeing that the memory associated with the
2919 * message will not be freed before this call returns.
2920 *
2921 * Return: zero on success, else a negative error code.
2922 */
2923int spi_sync(struct spi_device *spi, struct spi_message *message)
2924{
2925 int ret;
2926
2927 mutex_lock(&spi->master->bus_lock_mutex);
2928 ret = __spi_sync(spi, message);
2929 mutex_unlock(&spi->master->bus_lock_mutex);
2930
2931 return ret;
2932}
2933EXPORT_SYMBOL_GPL(spi_sync);
2934
2935/**
2936 * spi_sync_locked - version of spi_sync with exclusive bus usage
2937 * @spi: device with which data will be exchanged
2938 * @message: describes the data transfers
2939 * Context: can sleep
2940 *
2941 * This call may only be used from a context that may sleep. The sleep
2942 * is non-interruptible, and has no timeout. Low-overhead controller
2943 * drivers may DMA directly into and out of the message buffers.
2944 *
2945 * This call should be used by drivers that require exclusive access to the
2946 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
2947 * be released by a spi_bus_unlock call when the exclusive access is over.
2948 *
2949 * Return: zero on success, else a negative error code.
2950 */
2951int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2952{
2953 return __spi_sync(spi, message);
2954}
2955EXPORT_SYMBOL_GPL(spi_sync_locked);
2956
2957/**
2958 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2959 * @master: SPI bus master that should be locked for exclusive bus access
2960 * Context: can sleep
2961 *
2962 * This call may only be used from a context that may sleep. The sleep
2963 * is non-interruptible, and has no timeout.
2964 *
2965 * This call should be used by drivers that require exclusive access to the
2966 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2967 * exclusive access is over. Data transfer must be done by spi_sync_locked
2968 * and spi_async_locked calls when the SPI bus lock is held.
2969 *
2970 * Return: always zero.
2971 */
2972int spi_bus_lock(struct spi_master *master)
2973{
2974 unsigned long flags;
2975
2976 mutex_lock(&master->bus_lock_mutex);
2977
2978 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2979 master->bus_lock_flag = 1;
2980 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2981
2982 /* mutex remains locked until spi_bus_unlock is called */
2983
2984 return 0;
2985}
2986EXPORT_SYMBOL_GPL(spi_bus_lock);
2987
2988/**
2989 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2990 * @master: SPI bus master that was locked for exclusive bus access
2991 * Context: can sleep
2992 *
2993 * This call may only be used from a context that may sleep. The sleep
2994 * is non-interruptible, and has no timeout.
2995 *
2996 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2997 * call.
2998 *
2999 * Return: always zero.
3000 */
3001int spi_bus_unlock(struct spi_master *master)
3002{
3003 master->bus_lock_flag = 0;
3004
3005 mutex_unlock(&master->bus_lock_mutex);
3006
3007 return 0;
3008}
3009EXPORT_SYMBOL_GPL(spi_bus_unlock);
3010
3011/* portable code must never pass more than 32 bytes */
3012#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
3013
3014static u8 *buf;
3015
3016/**
3017 * spi_write_then_read - SPI synchronous write followed by read
3018 * @spi: device with which data will be exchanged
3019 * @txbuf: data to be written (need not be dma-safe)
3020 * @n_tx: size of txbuf, in bytes
3021 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3022 * @n_rx: size of rxbuf, in bytes
3023 * Context: can sleep
3024 *
3025 * This performs a half duplex MicroWire style transaction with the
3026 * device, sending txbuf and then reading rxbuf. The return value
3027 * is zero for success, else a negative errno status code.
3028 * This call may only be used from a context that may sleep.
3029 *
3030 * Parameters to this routine are always copied using a small buffer;
3031 * portable code should never use this for more than 32 bytes.
3032 * Performance-sensitive or bulk transfer code should instead use
3033 * spi_{async,sync}() calls with dma-safe buffers.
3034 *
3035 * Return: zero on success, else a negative error code.
3036 */
3037int spi_write_then_read(struct spi_device *spi,
3038 const void *txbuf, unsigned n_tx,
3039 void *rxbuf, unsigned n_rx)
3040{
3041 static DEFINE_MUTEX(lock);
3042
3043 int status;
3044 struct spi_message message;
3045 struct spi_transfer x[2];
3046 u8 *local_buf;
3047
3048 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3049 * copying here, (as a pure convenience thing), but we can
3050 * keep heap costs out of the hot path unless someone else is
3051 * using the pre-allocated buffer or the transfer is too large.
3052 */
3053 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
3054 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3055 GFP_KERNEL | GFP_DMA);
3056 if (!local_buf)
3057 return -ENOMEM;
3058 } else {
3059 local_buf = buf;
3060 }
3061
3062 spi_message_init(&message);
3063 memset(x, 0, sizeof(x));
3064 if (n_tx) {
3065 x[0].len = n_tx;
3066 spi_message_add_tail(&x[0], &message);
3067 }
3068 if (n_rx) {
3069 x[1].len = n_rx;
3070 spi_message_add_tail(&x[1], &message);
3071 }
3072
3073 memcpy(local_buf, txbuf, n_tx);
3074 x[0].tx_buf = local_buf;
3075 x[1].rx_buf = local_buf + n_tx;
3076
3077 /* do the i/o */
3078 status = spi_sync(spi, &message);
3079 if (status == 0)
3080 memcpy(rxbuf, x[1].rx_buf, n_rx);
3081
3082 if (x[0].tx_buf == buf)
3083 mutex_unlock(&lock);
3084 else
3085 kfree(local_buf);
3086
3087 return status;
3088}
3089EXPORT_SYMBOL_GPL(spi_write_then_read);
3090
3091/*-------------------------------------------------------------------------*/
3092
3093#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3094static int __spi_of_device_match(struct device *dev, void *data)
3095{
3096 return dev->of_node == data;
3097}
3098
3099/* must call put_device() when done with returned spi_device device */
3100static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3101{
3102 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3103 __spi_of_device_match);
3104 return dev ? to_spi_device(dev) : NULL;
3105}
3106
3107static int __spi_of_master_match(struct device *dev, const void *data)
3108{
3109 return dev->of_node == data;
3110}
3111
3112/* the spi masters are not using spi_bus, so we find it with another way */
3113static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3114{
3115 struct device *dev;
3116
3117 dev = class_find_device(&spi_master_class, NULL, node,
3118 __spi_of_master_match);
3119 if (!dev)
3120 return NULL;
3121
3122 /* reference got in class_find_device */
3123 return container_of(dev, struct spi_master, dev);
3124}
3125
3126static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3127 void *arg)
3128{
3129 struct of_reconfig_data *rd = arg;
3130 struct spi_master *master;
3131 struct spi_device *spi;
3132
3133 switch (of_reconfig_get_state_change(action, arg)) {
3134 case OF_RECONFIG_CHANGE_ADD:
3135 master = of_find_spi_master_by_node(rd->dn->parent);
3136 if (master == NULL)
3137 return NOTIFY_OK; /* not for us */
3138
3139 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3140 put_device(&master->dev);
3141 return NOTIFY_OK;
3142 }
3143
3144 spi = of_register_spi_device(master, rd->dn);
3145 put_device(&master->dev);
3146
3147 if (IS_ERR(spi)) {
3148 pr_err("%s: failed to create for '%s'\n",
3149 __func__, rd->dn->full_name);
3150 of_node_clear_flag(rd->dn, OF_POPULATED);
3151 return notifier_from_errno(PTR_ERR(spi));
3152 }
3153 break;
3154
3155 case OF_RECONFIG_CHANGE_REMOVE:
3156 /* already depopulated? */
3157 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3158 return NOTIFY_OK;
3159
3160 /* find our device by node */
3161 spi = of_find_spi_device_by_node(rd->dn);
3162 if (spi == NULL)
3163 return NOTIFY_OK; /* no? not meant for us */
3164
3165 /* unregister takes one ref away */
3166 spi_unregister_device(spi);
3167
3168 /* and put the reference of the find */
3169 put_device(&spi->dev);
3170 break;
3171 }
3172
3173 return NOTIFY_OK;
3174}
3175
3176static struct notifier_block spi_of_notifier = {
3177 .notifier_call = of_spi_notify,
3178};
3179#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3180extern struct notifier_block spi_of_notifier;
3181#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3182
3183#if IS_ENABLED(CONFIG_ACPI)
3184static int spi_acpi_master_match(struct device *dev, const void *data)
3185{
3186 return ACPI_COMPANION(dev->parent) == data;
3187}
3188
3189static int spi_acpi_device_match(struct device *dev, void *data)
3190{
3191 return ACPI_COMPANION(dev) == data;
3192}
3193
3194static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3195{
3196 struct device *dev;
3197
3198 dev = class_find_device(&spi_master_class, NULL, adev,
3199 spi_acpi_master_match);
3200 if (!dev)
3201 return NULL;
3202
3203 return container_of(dev, struct spi_master, dev);
3204}
3205
3206static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3207{
3208 struct device *dev;
3209
3210 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3211
3212 return dev ? to_spi_device(dev) : NULL;
3213}
3214
3215static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3216 void *arg)
3217{
3218 struct acpi_device *adev = arg;
3219 struct spi_master *master;
3220 struct spi_device *spi;
3221
3222 switch (value) {
3223 case ACPI_RECONFIG_DEVICE_ADD:
3224 master = acpi_spi_find_master_by_adev(adev->parent);
3225 if (!master)
3226 break;
3227
3228 acpi_register_spi_device(master, adev);
3229 put_device(&master->dev);
3230 break;
3231 case ACPI_RECONFIG_DEVICE_REMOVE:
3232 if (!acpi_device_enumerated(adev))
3233 break;
3234
3235 spi = acpi_spi_find_device_by_adev(adev);
3236 if (!spi)
3237 break;
3238
3239 spi_unregister_device(spi);
3240 put_device(&spi->dev);
3241 break;
3242 }
3243
3244 return NOTIFY_OK;
3245}
3246
3247static struct notifier_block spi_acpi_notifier = {
3248 .notifier_call = acpi_spi_notify,
3249};
3250#else
3251extern struct notifier_block spi_acpi_notifier;
3252#endif
3253
3254static int __init spi_init(void)
3255{
3256 int status;
3257
3258 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
3259 if (!buf) {
3260 status = -ENOMEM;
3261 goto err0;
3262 }
3263
3264 status = bus_register(&spi_bus_type);
3265 if (status < 0)
3266 goto err1;
3267
3268 status = class_register(&spi_master_class);
3269 if (status < 0)
3270 goto err2;
3271
3272 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
3273 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3274 if (IS_ENABLED(CONFIG_ACPI))
3275 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
3276
3277 return 0;
3278
3279err2:
3280 bus_unregister(&spi_bus_type);
3281err1:
3282 kfree(buf);
3283 buf = NULL;
3284err0:
3285 return status;
3286}
3287
3288/* board_info is normally registered in arch_initcall(),
3289 * but even essential drivers wait till later
3290 *
3291 * REVISIT only boardinfo really needs static linking. the rest (device and
3292 * driver registration) _could_ be dynamically linked (modular) ... costs
3293 * include needing to have boardinfo data structures be much more public.
3294 */
3295postcore_initcall(spi_init);
3296