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net: phy: fix potential race in the phylib state machine
[linux-2.6-block.git] / drivers / spi / spi.c
CommitLineData
b445bfcb 1// SPDX-License-Identifier: GPL-2.0-or-later
787f4889
MB		 2// SPI init/core code
3//
4// Copyright (C) 2005 David Brownell
5// Copyright (C) 2008 Secret Lab Technologies Ltd.
8ae12a0d 6
8ae12a0d
DB		 7#include <linux/kernel.h>
8#include <linux/device.h>
9#include <linux/init.h>
10#include <linux/cache.h>
99adef31
MB		 11#include <linux/dma-mapping.h>
12#include <linux/dmaengine.h>
94040828 13#include <linux/mutex.h>
2b7a32f7 14#include <linux/of_device.h>
d57a4282 15#include <linux/of_irq.h>
86be408b 16#include <linux/clk/clk-conf.h>
5a0e3ad6 17#include <linux/slab.h>
e0626e38 18#include <linux/mod_devicetable.h>
8ae12a0d 19#include <linux/spi/spi.h>
b5932f5c 20#include <linux/spi/spi-mem.h>
74317984 21#include <linux/of_gpio.h>
3ae22e8c 22#include <linux/pm_runtime.h>
f48c767c 23#include <linux/pm_domain.h>
826cf175 24#include <linux/property.h>
025ed130 25#include <linux/export.h>
8bd75c77 26#include <linux/sched/rt.h>
ae7e81c0 27#include <uapi/linux/sched/types.h>
ffbbdd21
LW		 28#include <linux/delay.h>
29#include <linux/kthread.h>
64bee4d2
MW		 30#include <linux/ioport.h>
31#include <linux/acpi.h>
b1b8153c 32#include <linux/highmem.h>
9b61e302 33#include <linux/idr.h>
8a2e487e 34#include <linux/platform_data/x86/apple.h>
8ae12a0d 35
56ec1978
MB		 36#define CREATE_TRACE_POINTS
37#include <trace/events/spi.h>
9b61e302 38
46336966
BB		 39#include "internals.h"
40
9b61e302 41static DEFINE_IDR(spi_master_idr);
56ec1978 42
8ae12a0d
DB		 43static void spidev_release(struct device *dev)
44{
0ffa0285 45 struct spi_device *spi = to_spi_device(dev);
8ae12a0d 46
8caab75f
GU		 47 /* spi controllers may cleanup for released devices */
48 if (spi->controller->cleanup)
49 spi->controller->cleanup(spi);
8ae12a0d 50
8caab75f 51 spi_controller_put(spi->controller);
5039563e 52 kfree(spi->driver_override);
07a389fe 53 kfree(spi);
8ae12a0d
DB		 54}
55
56static ssize_t
57modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58{
59 const struct spi_device *spi = to_spi_device(dev);
8c4ff6d0
ZR		 60 int len;
61
62 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
63 if (len != -ENODEV)
64 return len;
8ae12a0d 65
d8e328b3 66 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
8ae12a0d 67}
aa7da564 68static DEVICE_ATTR_RO(modalias);
8ae12a0d 69
5039563e
TP		 70static ssize_t driver_override_store(struct device *dev,
71 struct device_attribute *a,
72 const char *buf, size_t count)
73{
74 struct spi_device *spi = to_spi_device(dev);
75 const char *end = memchr(buf, '\n', count);
76 const size_t len = end ? end - buf : count;
77 const char *driver_override, *old;
78
79 /* We need to keep extra room for a newline when displaying value */
80 if (len >= (PAGE_SIZE - 1))
81 return -EINVAL;
82
83 driver_override = kstrndup(buf, len, GFP_KERNEL);
84 if (!driver_override)
85 return -ENOMEM;
86
87 device_lock(dev);
88 old = spi->driver_override;
89 if (len) {
90 spi->driver_override = driver_override;
91 } else {
92 /* Emptry string, disable driver override */
93 spi->driver_override = NULL;
94 kfree(driver_override);
95 }
96 device_unlock(dev);
97 kfree(old);
98
99 return count;
100}
101
102static ssize_t driver_override_show(struct device *dev,
103 struct device_attribute *a, char *buf)
104{
105 const struct spi_device *spi = to_spi_device(dev);
106 ssize_t len;
107
108 device_lock(dev);
109 len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
110 device_unlock(dev);
111 return len;
112}
113static DEVICE_ATTR_RW(driver_override);
114
eca2ebc7 115#define SPI_STATISTICS_ATTRS(field, file) \
8caab75f
GU		 116static ssize_t spi_controller_##field##_show(struct device *dev, \
117 struct device_attribute *attr, \
118 char *buf) \
eca2ebc7 119{ \
8caab75f
GU		 120 struct spi_controller *ctlr = container_of(dev, \
121 struct spi_controller, dev); \
122 return spi_statistics_##field##_show(&ctlr->statistics, buf); \
eca2ebc7 123} \
8caab75f 124static struct device_attribute dev_attr_spi_controller_##field = { \
ad25c92e 125 .attr = { .name = file, .mode = 0444 }, \
8caab75f 126 .show = spi_controller_##field##_show, \
eca2ebc7
MS		 127}; \
128static ssize_t spi_device_##field##_show(struct device *dev, \
129 struct device_attribute *attr, \
130 char *buf) \
131{ \
d1eba93b 132 struct spi_device *spi = to_spi_device(dev); \
eca2ebc7
MS		 133 return spi_statistics_##field##_show(&spi->statistics, buf); \
134} \
135static struct device_attribute dev_attr_spi_device_##field = { \
ad25c92e 136 .attr = { .name = file, .mode = 0444 }, \
eca2ebc7
MS		 137 .show = spi_device_##field##_show, \
138}
139
140#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
141static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
142 char *buf) \
143{ \
144 unsigned long flags; \
145 ssize_t len; \
146 spin_lock_irqsave(&stat->lock, flags); \
147 len = sprintf(buf, format_string, stat->field); \
148 spin_unlock_irqrestore(&stat->lock, flags); \
149 return len; \
150} \
151SPI_STATISTICS_ATTRS(name, file)
152
153#define SPI_STATISTICS_SHOW(field, format_string) \
154 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
155 field, format_string)
156
157SPI_STATISTICS_SHOW(messages, "%lu");
158SPI_STATISTICS_SHOW(transfers, "%lu");
159SPI_STATISTICS_SHOW(errors, "%lu");
160SPI_STATISTICS_SHOW(timedout, "%lu");
161
162SPI_STATISTICS_SHOW(spi_sync, "%lu");
163SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
164SPI_STATISTICS_SHOW(spi_async, "%lu");
165
166SPI_STATISTICS_SHOW(bytes, "%llu");
167SPI_STATISTICS_SHOW(bytes_rx, "%llu");
168SPI_STATISTICS_SHOW(bytes_tx, "%llu");
169
6b7bc061
MS		 170#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
171 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
172 "transfer_bytes_histo_" number, \
173 transfer_bytes_histo[index], "%lu")
174SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
175SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
176SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
177SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
178SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
179SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
180SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
181SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
182SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
183SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
184SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
185SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
186SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
187SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
188SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
189SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
190SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
191
d9f12122
MS		 192SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
193
aa7da564
GKH		 194static struct attribute *spi_dev_attrs[] = {
195 &dev_attr_modalias.attr,
5039563e 196 &dev_attr_driver_override.attr,
aa7da564 197 NULL,
8ae12a0d 198};
eca2ebc7
MS		 199
200static const struct attribute_group spi_dev_group = {
201 .attrs = spi_dev_attrs,
202};
203
204static struct attribute *spi_device_statistics_attrs[] = {
205 &dev_attr_spi_device_messages.attr,
206 &dev_attr_spi_device_transfers.attr,
207 &dev_attr_spi_device_errors.attr,
208 &dev_attr_spi_device_timedout.attr,
209 &dev_attr_spi_device_spi_sync.attr,
210 &dev_attr_spi_device_spi_sync_immediate.attr,
211 &dev_attr_spi_device_spi_async.attr,
212 &dev_attr_spi_device_bytes.attr,
213 &dev_attr_spi_device_bytes_rx.attr,
214 &dev_attr_spi_device_bytes_tx.attr,
6b7bc061
MS		 215 &dev_attr_spi_device_transfer_bytes_histo0.attr,
216 &dev_attr_spi_device_transfer_bytes_histo1.attr,
217 &dev_attr_spi_device_transfer_bytes_histo2.attr,
218 &dev_attr_spi_device_transfer_bytes_histo3.attr,
219 &dev_attr_spi_device_transfer_bytes_histo4.attr,
220 &dev_attr_spi_device_transfer_bytes_histo5.attr,
221 &dev_attr_spi_device_transfer_bytes_histo6.attr,
222 &dev_attr_spi_device_transfer_bytes_histo7.attr,
223 &dev_attr_spi_device_transfer_bytes_histo8.attr,
224 &dev_attr_spi_device_transfer_bytes_histo9.attr,
225 &dev_attr_spi_device_transfer_bytes_histo10.attr,
226 &dev_attr_spi_device_transfer_bytes_histo11.attr,
227 &dev_attr_spi_device_transfer_bytes_histo12.attr,
228 &dev_attr_spi_device_transfer_bytes_histo13.attr,
229 &dev_attr_spi_device_transfer_bytes_histo14.attr,
230 &dev_attr_spi_device_transfer_bytes_histo15.attr,
231 &dev_attr_spi_device_transfer_bytes_histo16.attr,
d9f12122 232 &dev_attr_spi_device_transfers_split_maxsize.attr,
eca2ebc7
MS		 233 NULL,
234};
235
236static const struct attribute_group spi_device_statistics_group = {
237 .name = "statistics",
238 .attrs = spi_device_statistics_attrs,
239};
240
241static const struct attribute_group *spi_dev_groups[] = {
242 &spi_dev_group,
243 &spi_device_statistics_group,
244 NULL,
245};
246
8caab75f
GU		 247static struct attribute *spi_controller_statistics_attrs[] = {
248 &dev_attr_spi_controller_messages.attr,
249 &dev_attr_spi_controller_transfers.attr,
250 &dev_attr_spi_controller_errors.attr,
251 &dev_attr_spi_controller_timedout.attr,
252 &dev_attr_spi_controller_spi_sync.attr,
253 &dev_attr_spi_controller_spi_sync_immediate.attr,
254 &dev_attr_spi_controller_spi_async.attr,
255 &dev_attr_spi_controller_bytes.attr,
256 &dev_attr_spi_controller_bytes_rx.attr,
257 &dev_attr_spi_controller_bytes_tx.attr,
258 &dev_attr_spi_controller_transfer_bytes_histo0.attr,
259 &dev_attr_spi_controller_transfer_bytes_histo1.attr,
260 &dev_attr_spi_controller_transfer_bytes_histo2.attr,
261 &dev_attr_spi_controller_transfer_bytes_histo3.attr,
262 &dev_attr_spi_controller_transfer_bytes_histo4.attr,
263 &dev_attr_spi_controller_transfer_bytes_histo5.attr,
264 &dev_attr_spi_controller_transfer_bytes_histo6.attr,
265 &dev_attr_spi_controller_transfer_bytes_histo7.attr,
266 &dev_attr_spi_controller_transfer_bytes_histo8.attr,
267 &dev_attr_spi_controller_transfer_bytes_histo9.attr,
268 &dev_attr_spi_controller_transfer_bytes_histo10.attr,
269 &dev_attr_spi_controller_transfer_bytes_histo11.attr,
270 &dev_attr_spi_controller_transfer_bytes_histo12.attr,
271 &dev_attr_spi_controller_transfer_bytes_histo13.attr,
272 &dev_attr_spi_controller_transfer_bytes_histo14.attr,
273 &dev_attr_spi_controller_transfer_bytes_histo15.attr,
274 &dev_attr_spi_controller_transfer_bytes_histo16.attr,
275 &dev_attr_spi_controller_transfers_split_maxsize.attr,
eca2ebc7
MS		 276 NULL,
277};
278
8caab75f 279static const struct attribute_group spi_controller_statistics_group = {
eca2ebc7 280 .name = "statistics",
8caab75f 281 .attrs = spi_controller_statistics_attrs,
eca2ebc7
MS		 282};
283
284static const struct attribute_group *spi_master_groups[] = {
8caab75f 285 &spi_controller_statistics_group,
eca2ebc7
MS		 286 NULL,
287};
288
289void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
290 struct spi_transfer *xfer,
8caab75f 291 struct spi_controller *ctlr)
eca2ebc7
MS		 292{
293 unsigned long flags;
6b7bc061
MS		 294 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
295
296 if (l2len < 0)
297 l2len = 0;
eca2ebc7
MS		 298
299 spin_lock_irqsave(&stats->lock, flags);
300
301 stats->transfers++;
6b7bc061 302 stats->transfer_bytes_histo[l2len]++;
eca2ebc7
MS		 303
304 stats->bytes += xfer->len;
305 if ((xfer->tx_buf) &&
8caab75f 306 (xfer->tx_buf != ctlr->dummy_tx))
eca2ebc7
MS		 307 stats->bytes_tx += xfer->len;
308 if ((xfer->rx_buf) &&
8caab75f 309 (xfer->rx_buf != ctlr->dummy_rx))
eca2ebc7
MS		 310 stats->bytes_rx += xfer->len;
311
312 spin_unlock_irqrestore(&stats->lock, flags);
313}
314EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
8ae12a0d
DB		 315
316/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
317 * and the sysfs version makes coldplug work too.
318 */
319
75368bf6
AV		 320static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
321 const struct spi_device *sdev)
322{
323 while (id->name[0]) {
324 if (!strcmp(sdev->modalias, id->name))
325 return id;
326 id++;
327 }
328 return NULL;
329}
330
331const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
332{
333 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
334
335 return spi_match_id(sdrv->id_table, sdev);
336}
337EXPORT_SYMBOL_GPL(spi_get_device_id);
338
8ae12a0d
DB		 339static int spi_match_device(struct device *dev, struct device_driver *drv)
340{
341 const struct spi_device *spi = to_spi_device(dev);
75368bf6
AV		 342 const struct spi_driver *sdrv = to_spi_driver(drv);
343
5039563e
TP		 344 /* Check override first, and if set, only use the named driver */
345 if (spi->driver_override)
346 return strcmp(spi->driver_override, drv->name) == 0;
347
2b7a32f7
SA		 348 /* Attempt an OF style match */
349 if (of_driver_match_device(dev, drv))
350 return 1;
351
64bee4d2
MW		 352 /* Then try ACPI */
353 if (acpi_driver_match_device(dev, drv))
354 return 1;
355
75368bf6
AV		 356 if (sdrv->id_table)
357 return !!spi_match_id(sdrv->id_table, spi);
8ae12a0d 358
35f74fca 359 return strcmp(spi->modalias, drv->name) == 0;
8ae12a0d
DB		 360}
361
7eff2e7a 362static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
8ae12a0d
DB		 363{
364 const struct spi_device *spi = to_spi_device(dev);
8c4ff6d0
ZR		 365 int rc;
366
367 rc = acpi_device_uevent_modalias(dev, env);
368 if (rc != -ENODEV)
369 return rc;
8ae12a0d 370
2856670f 371 return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
8ae12a0d
DB		 372}
373
8ae12a0d
DB		 374struct bus_type spi_bus_type = {
375 .name = "spi",
aa7da564 376 .dev_groups = spi_dev_groups,
8ae12a0d
DB		 377 .match = spi_match_device,
378 .uevent = spi_uevent,
8ae12a0d
DB		 379};
380EXPORT_SYMBOL_GPL(spi_bus_type);
381
b885244e
DB		 382
383static int spi_drv_probe(struct device *dev)
384{
385 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
44af7927 386 struct spi_device *spi = to_spi_device(dev);
33cf00e5
MW		 387 int ret;
388
86be408b
SN		 389 ret = of_clk_set_defaults(dev->of_node, false);
390 if (ret)
391 return ret;
392
44af7927
JH		 393 if (dev->of_node) {
394 spi->irq = of_irq_get(dev->of_node, 0);
395 if (spi->irq == -EPROBE_DEFER)
396 return -EPROBE_DEFER;
397 if (spi->irq < 0)
398 spi->irq = 0;
399 }
400
676e7c25 401 ret = dev_pm_domain_attach(dev, true);
71f277a7
UH		 402 if (ret)
403 return ret;
404
405 ret = sdrv->probe(spi);
406 if (ret)
407 dev_pm_domain_detach(dev, true);
b885244e 408
33cf00e5 409 return ret;
b885244e
DB		 410}
411
412static int spi_drv_remove(struct device *dev)
413{
414 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
33cf00e5
MW		 415 int ret;
416
aec35f4e 417 ret = sdrv->remove(to_spi_device(dev));
676e7c25 418 dev_pm_domain_detach(dev, true);
b885244e 419
33cf00e5 420 return ret;
b885244e
DB		 421}
422
423static void spi_drv_shutdown(struct device *dev)
424{
425 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
426
427 sdrv->shutdown(to_spi_device(dev));
428}
429
33e34dc6 430/**
ca5d2485 431 * __spi_register_driver - register a SPI driver
88c9321d 432 * @owner: owner module of the driver to register
33e34dc6
DB		 433 * @sdrv: the driver to register
434 * Context: can sleep
97d56dc6
JMC		 435 *
436 * Return: zero on success, else a negative error code.
33e34dc6 437 */
ca5d2485 438int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
b885244e 439{
ca5d2485 440 sdrv->driver.owner = owner;
b885244e
DB		 441 sdrv->driver.bus = &spi_bus_type;
442 if (sdrv->probe)
443 sdrv->driver.probe = spi_drv_probe;
444 if (sdrv->remove)
445 sdrv->driver.remove = spi_drv_remove;
446 if (sdrv->shutdown)
447 sdrv->driver.shutdown = spi_drv_shutdown;
448 return driver_register(&sdrv->driver);
449}
ca5d2485 450EXPORT_SYMBOL_GPL(__spi_register_driver);
b885244e 451
8ae12a0d
DB		 452/*-------------------------------------------------------------------------*/
453
454/* SPI devices should normally not be created by SPI device drivers; that
8caab75f 455 * would make them board-specific. Similarly with SPI controller drivers.
8ae12a0d
DB		 456 * Device registration normally goes into like arch/.../mach.../board-YYY.c
457 * with other readonly (flashable) information about mainboard devices.
458 */
459
460struct boardinfo {
461 struct list_head list;
2b9603a0 462 struct spi_board_info board_info;
8ae12a0d
DB		 463};
464
465static LIST_HEAD(board_list);
8caab75f 466static LIST_HEAD(spi_controller_list);
2b9603a0
FT		 467
468/*
469 * Used to protect add/del opertion for board_info list and
8caab75f 470 * spi_controller list, and their matching process
9a9a047a 471 * also used to protect object of type struct idr
2b9603a0 472 */
94040828 473static DEFINE_MUTEX(board_lock);
8ae12a0d 474
dc87c98e
GL		 475/**
476 * spi_alloc_device - Allocate a new SPI device
8caab75f 477 * @ctlr: Controller to which device is connected
dc87c98e
GL		 478 * Context: can sleep
479 *
480 * Allows a driver to allocate and initialize a spi_device without
481 * registering it immediately. This allows a driver to directly
482 * fill the spi_device with device parameters before calling
483 * spi_add_device() on it.
484 *
485 * Caller is responsible to call spi_add_device() on the returned
8caab75f 486 * spi_device structure to add it to the SPI controller. If the caller
dc87c98e
GL		 487 * needs to discard the spi_device without adding it, then it should
488 * call spi_dev_put() on it.
489 *
97d56dc6 490 * Return: a pointer to the new device, or NULL.
dc87c98e 491 */
8caab75f 492struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
dc87c98e
GL		 493{
494 struct spi_device *spi;
dc87c98e 495
8caab75f 496 if (!spi_controller_get(ctlr))
dc87c98e
GL		 497 return NULL;
498
5fe5f05e 499 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
dc87c98e 500 if (!spi) {
8caab75f 501 spi_controller_put(ctlr);
dc87c98e
GL		 502 return NULL;
503 }
504
8caab75f
GU		 505 spi->master = spi->controller = ctlr;
506 spi->dev.parent = &ctlr->dev;
dc87c98e
GL		 507 spi->dev.bus = &spi_bus_type;
508 spi->dev.release = spidev_release;
446411e1 509 spi->cs_gpio = -ENOENT;
eca2ebc7
MS		 510
511 spin_lock_init(&spi->statistics.lock);
512
dc87c98e
GL		 513 device_initialize(&spi->dev);
514 return spi;
515}
516EXPORT_SYMBOL_GPL(spi_alloc_device);
517
e13ac47b
JN		 518static void spi_dev_set_name(struct spi_device *spi)
519{
520 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
521
522 if (adev) {
523 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
524 return;
525 }
526
8caab75f 527 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
e13ac47b
JN		 528 spi->chip_select);
529}
530
b6fb8d3a
MW		 531static int spi_dev_check(struct device *dev, void *data)
532{
533 struct spi_device *spi = to_spi_device(dev);
534 struct spi_device *new_spi = data;
535
8caab75f 536 if (spi->controller == new_spi->controller &&
b6fb8d3a
MW		 537 spi->chip_select == new_spi->chip_select)
538 return -EBUSY;
539 return 0;
540}
541
dc87c98e
GL		 542/**
543 * spi_add_device - Add spi_device allocated with spi_alloc_device
544 * @spi: spi_device to register
545 *
546 * Companion function to spi_alloc_device. Devices allocated with
547 * spi_alloc_device can be added onto the spi bus with this function.
548 *
97d56dc6 549 * Return: 0 on success; negative errno on failure
dc87c98e
GL		 550 */
551int spi_add_device(struct spi_device *spi)
552{
e48880e0 553 static DEFINE_MUTEX(spi_add_lock);
8caab75f
GU		 554 struct spi_controller *ctlr = spi->controller;
555 struct device *dev = ctlr->dev.parent;
dc87c98e
GL		 556 int status;
557
558 /* Chipselects are numbered 0..max; validate. */
8caab75f
GU		 559 if (spi->chip_select >= ctlr->num_chipselect) {
560 dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
561 ctlr->num_chipselect);
dc87c98e
GL		 562 return -EINVAL;
563 }
564
565 /* Set the bus ID string */
e13ac47b 566 spi_dev_set_name(spi);
e48880e0
DB		 567
568 /* We need to make sure there's no other device with this
569 * chipselect **BEFORE** we call setup(), else we'll trash
570 * its configuration. Lock against concurrent add() calls.
571 */
572 mutex_lock(&spi_add_lock);
573
b6fb8d3a
MW		 574 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
575 if (status) {
e48880e0
DB		 576 dev_err(dev, "chipselect %d already in use\n",
577 spi->chip_select);
e48880e0
DB		 578 goto done;
579 }
580
8caab75f
GU		 581 if (ctlr->cs_gpios)
582 spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
74317984 583
e48880e0
DB		 584 /* Drivers may modify this initial i/o setup, but will
585 * normally rely on the device being setup. Devices
586 * using SPI_CS_HIGH can't coexist well otherwise...
587 */
7d077197 588 status = spi_setup(spi);
dc87c98e 589 if (status < 0) {
eb288a1f
LW		 590 dev_err(dev, "can't setup %s, status %d\n",
591 dev_name(&spi->dev), status);
e48880e0 592 goto done;
dc87c98e
GL		 593 }
594
e48880e0 595 /* Device may be bound to an active driver when this returns */
dc87c98e 596 status = device_add(&spi->dev);
e48880e0 597 if (status < 0)
eb288a1f
LW		 598 dev_err(dev, "can't add %s, status %d\n",
599 dev_name(&spi->dev), status);
e48880e0 600 else
35f74fca 601 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
dc87c98e 602
e48880e0
DB		 603done:
604 mutex_unlock(&spi_add_lock);
605 return status;
dc87c98e
GL		 606}
607EXPORT_SYMBOL_GPL(spi_add_device);
8ae12a0d 608
33e34dc6
DB		 609/**
610 * spi_new_device - instantiate one new SPI device
8caab75f 611 * @ctlr: Controller to which device is connected
33e34dc6
DB		 612 * @chip: Describes the SPI device
613 * Context: can sleep
614 *
615 * On typical mainboards, this is purely internal; and it's not needed
8ae12a0d
DB		 616 * after board init creates the hard-wired devices. Some development
617 * platforms may not be able to use spi_register_board_info though, and
618 * this is exported so that for example a USB or parport based adapter
619 * driver could add devices (which it would learn about out-of-band).
082c8cb4 620 *
97d56dc6 621 * Return: the new device, or NULL.
8ae12a0d 622 */
8caab75f 623struct spi_device *spi_new_device(struct spi_controller *ctlr,
e9d5a461 624 struct spi_board_info *chip)
8ae12a0d
DB		 625{
626 struct spi_device *proxy;
8ae12a0d
DB		 627 int status;
628
082c8cb4
DB		 629 /* NOTE: caller did any chip->bus_num checks necessary.
630 *
631 * Also, unless we change the return value convention to use
632 * error-or-pointer (not NULL-or-pointer), troubleshootability
633 * suggests syslogged diagnostics are best here (ugh).
634 */
635
8caab75f 636 proxy = spi_alloc_device(ctlr);
dc87c98e 637 if (!proxy)
8ae12a0d
DB		 638 return NULL;
639
102eb975
GL		 640 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
641
8ae12a0d
DB		 642 proxy->chip_select = chip->chip_select;
643 proxy->max_speed_hz = chip->max_speed_hz;
980a01c9 644 proxy->mode = chip->mode;
8ae12a0d 645 proxy->irq = chip->irq;
102eb975 646 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
8ae12a0d
DB		 647 proxy->dev.platform_data = (void *) chip->platform_data;
648 proxy->controller_data = chip->controller_data;
649 proxy->controller_state = NULL;
8ae12a0d 650
826cf175
DT		 651 if (chip->properties) {
652 status = device_add_properties(&proxy->dev, chip->properties);
653 if (status) {
8caab75f 654 dev_err(&ctlr->dev,
826cf175
DT		 655 "failed to add properties to '%s': %d\n",
656 chip->modalias, status);
657 goto err_dev_put;
658 }
8ae12a0d
DB		 659 }
660
826cf175
DT		 661 status = spi_add_device(proxy);
662 if (status < 0)
663 goto err_remove_props;
664
8ae12a0d 665 return proxy;
826cf175
DT		 666
667err_remove_props:
668 if (chip->properties)
669 device_remove_properties(&proxy->dev);
670err_dev_put:
671 spi_dev_put(proxy);
672 return NULL;
8ae12a0d
DB		 673}
674EXPORT_SYMBOL_GPL(spi_new_device);
675
3b1884c2
GU		 676/**
677 * spi_unregister_device - unregister a single SPI device
678 * @spi: spi_device to unregister
679 *
680 * Start making the passed SPI device vanish. Normally this would be handled
8caab75f 681 * by spi_unregister_controller().
3b1884c2
GU		 682 */
683void spi_unregister_device(struct spi_device *spi)
684{
bd6c1644
GU		 685 if (!spi)
686 return;
687
8324147f 688 if (spi->dev.of_node) {
bd6c1644 689 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
8324147f
JH		 690 of_node_put(spi->dev.of_node);
691 }
7f24467f
OP		 692 if (ACPI_COMPANION(&spi->dev))
693 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
bd6c1644 694 device_unregister(&spi->dev);
3b1884c2
GU		 695}
696EXPORT_SYMBOL_GPL(spi_unregister_device);
697
8caab75f
GU		 698static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
699 struct spi_board_info *bi)
2b9603a0
FT		 700{
701 struct spi_device *dev;
702
8caab75f 703 if (ctlr->bus_num != bi->bus_num)
2b9603a0
FT		 704 return;
705
8caab75f 706 dev = spi_new_device(ctlr, bi);
2b9603a0 707 if (!dev)
8caab75f 708 dev_err(ctlr->dev.parent, "can't create new device for %s\n",
2b9603a0
FT		 709 bi->modalias);
710}
711
33e34dc6
DB		 712/**
713 * spi_register_board_info - register SPI devices for a given board
714 * @info: array of chip descriptors
715 * @n: how many descriptors are provided
716 * Context: can sleep
717 *
8ae12a0d
DB		 718 * Board-specific early init code calls this (probably during arch_initcall)
719 * with segments of the SPI device table. Any device nodes are created later,
720 * after the relevant parent SPI controller (bus_num) is defined. We keep
721 * this table of devices forever, so that reloading a controller driver will
722 * not make Linux forget about these hard-wired devices.
723 *
724 * Other code can also call this, e.g. a particular add-on board might provide
725 * SPI devices through its expansion connector, so code initializing that board
726 * would naturally declare its SPI devices.
727 *
728 * The board info passed can safely be __initdata ... but be careful of
729 * any embedded pointers (platform_data, etc), they're copied as-is.
826cf175 730 * Device properties are deep-copied though.
97d56dc6
JMC		 731 *
732 * Return: zero on success, else a negative error code.
8ae12a0d 733 */
fd4a319b 734int spi_register_board_info(struct spi_board_info const *info, unsigned n)
8ae12a0d 735{
2b9603a0
FT		 736 struct boardinfo *bi;
737 int i;
8ae12a0d 738
c7908a37 739 if (!n)
f974cf57 740 return 0;
c7908a37 741
f9bdb7fd 742 bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
8ae12a0d
DB		 743 if (!bi)
744 return -ENOMEM;
8ae12a0d 745
2b9603a0 746 for (i = 0; i < n; i++, bi++, info++) {
8caab75f 747 struct spi_controller *ctlr;
8ae12a0d 748
2b9603a0 749 memcpy(&bi->board_info, info, sizeof(*info));
826cf175
DT		 750 if (info->properties) {
751 bi->board_info.properties =
752 property_entries_dup(info->properties);
753 if (IS_ERR(bi->board_info.properties))
754 return PTR_ERR(bi->board_info.properties);
755 }
756
2b9603a0
FT		 757 mutex_lock(&board_lock);
758 list_add_tail(&bi->list, &board_list);
8caab75f
GU		 759 list_for_each_entry(ctlr, &spi_controller_list, list)
760 spi_match_controller_to_boardinfo(ctlr,
761 &bi->board_info);
2b9603a0 762 mutex_unlock(&board_lock);
8ae12a0d 763 }
2b9603a0
FT		 764
765 return 0;
8ae12a0d
DB		 766}
767
768/*-------------------------------------------------------------------------*/
769
b158935f
MB		 770static void spi_set_cs(struct spi_device *spi, bool enable)
771{
772 if (spi->mode & SPI_CS_HIGH)
773 enable = !enable;
774
8eee6b9d 775 if (gpio_is_valid(spi->cs_gpio)) {
25972d0c
PE		 776 /* Honour the SPI_NO_CS flag */
777 if (!(spi->mode & SPI_NO_CS))
778 gpio_set_value(spi->cs_gpio, !enable);
8eee6b9d 779 /* Some SPI masters need both GPIO CS & slave_select */
8caab75f
GU		 780 if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
781 spi->controller->set_cs)
782 spi->controller->set_cs(spi, !enable);
783 } else if (spi->controller->set_cs) {
784 spi->controller->set_cs(spi, !enable);
8eee6b9d 785 }
b158935f
MB		 786}
787
2de440f5 788#ifdef CONFIG_HAS_DMA
46336966
BB		 789int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
790 struct sg_table *sgt, void *buf, size_t len,
791 enum dma_data_direction dir)
6ad45a27
MB		 792{
793 const bool vmalloced_buf = is_vmalloc_addr(buf);
df88e91b 794 unsigned int max_seg_size = dma_get_max_seg_size(dev);
b1b8153c
V		 795#ifdef CONFIG_HIGHMEM
796 const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
797 (unsigned long)buf < (PKMAP_BASE +
798 (LAST_PKMAP * PAGE_SIZE)));
799#else
800 const bool kmap_buf = false;
801#endif
65598c13
AG		 802 int desc_len;
803 int sgs;
6ad45a27 804 struct page *vm_page;
8dd4a016 805 struct scatterlist *sg;
6ad45a27
MB		 806 void *sg_buf;
807 size_t min;
808 int i, ret;
809
b1b8153c 810 if (vmalloced_buf || kmap_buf) {
df88e91b 811 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
65598c13 812 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
0569a88f 813 } else if (virt_addr_valid(buf)) {
8caab75f 814 desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
65598c13 815 sgs = DIV_ROUND_UP(len, desc_len);
0569a88f
V		 816 } else {
817 return -EINVAL;
65598c13
AG		 818 }
819
6ad45a27
MB		 820 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
821 if (ret != 0)
822 return ret;
823
8dd4a016 824 sg = &sgt->sgl[0];
6ad45a27 825 for (i = 0; i < sgs; i++) {
6ad45a27 826
b1b8153c 827 if (vmalloced_buf || kmap_buf) {
ce99319a
MC		 828 /*
829 * Next scatterlist entry size is the minimum between
830 * the desc_len and the remaining buffer length that
831 * fits in a page.
832 */
833 min = min_t(size_t, desc_len,
834 min_t(size_t, len,
835 PAGE_SIZE - offset_in_page(buf)));
b1b8153c
V		 836 if (vmalloced_buf)
837 vm_page = vmalloc_to_page(buf);
838 else
839 vm_page = kmap_to_page(buf);
6ad45a27
MB		 840 if (!vm_page) {
841 sg_free_table(sgt);
842 return -ENOMEM;
843 }
8dd4a016 844 sg_set_page(sg, vm_page,
c1aefbdd 845 min, offset_in_page(buf));
6ad45a27 846 } else {
65598c13 847 min = min_t(size_t, len, desc_len);
6ad45a27 848 sg_buf = buf;
8dd4a016 849 sg_set_buf(sg, sg_buf, min);
6ad45a27
MB		 850 }
851
6ad45a27
MB		 852 buf += min;
853 len -= min;
8dd4a016 854 sg = sg_next(sg);
6ad45a27
MB		 855 }
856
857 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
89e4b66a
GU		 858 if (!ret)
859 ret = -ENOMEM;
6ad45a27
MB		 860 if (ret < 0) {
861 sg_free_table(sgt);
862 return ret;
863 }
864
865 sgt->nents = ret;
866
867 return 0;
868}
869
46336966
BB		 870void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
871 struct sg_table *sgt, enum dma_data_direction dir)
6ad45a27
MB		 872{
873 if (sgt->orig_nents) {
874 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
875 sg_free_table(sgt);
876 }
877}
878
8caab75f 879static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
99adef31 880{
99adef31
MB		 881 struct device *tx_dev, *rx_dev;
882 struct spi_transfer *xfer;
6ad45a27 883 int ret;
3a2eba9b 884
8caab75f 885 if (!ctlr->can_dma)
99adef31
MB		 886 return 0;
887
8caab75f
GU		 888 if (ctlr->dma_tx)
889 tx_dev = ctlr->dma_tx->device->dev;
c37f45b5 890 else
8caab75f 891 tx_dev = ctlr->dev.parent;
c37f45b5 892
8caab75f
GU		 893 if (ctlr->dma_rx)
894 rx_dev = ctlr->dma_rx->device->dev;
c37f45b5 895 else
8caab75f 896 rx_dev = ctlr->dev.parent;
99adef31
MB		 897
898 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
8caab75f 899 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
99adef31
MB		 900 continue;
901
902 if (xfer->tx_buf != NULL) {
8caab75f 903 ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
6ad45a27
MB		 904 (void *)xfer->tx_buf, xfer->len,
905 DMA_TO_DEVICE);
906 if (ret != 0)
907 return ret;
99adef31
MB		 908 }
909
910 if (xfer->rx_buf != NULL) {
8caab75f 911 ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
6ad45a27
MB		 912 xfer->rx_buf, xfer->len,
913 DMA_FROM_DEVICE);
914 if (ret != 0) {
8caab75f 915 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
6ad45a27
MB		 916 DMA_TO_DEVICE);
917 return ret;
99adef31
MB		 918 }
919 }
920 }
921
8caab75f 922 ctlr->cur_msg_mapped = true;
99adef31
MB		 923
924 return 0;
925}
926
8caab75f 927static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
99adef31
MB		 928{
929 struct spi_transfer *xfer;
930 struct device *tx_dev, *rx_dev;
931
8caab75f 932 if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
99adef31
MB		 933 return 0;
934
8caab75f
GU		 935 if (ctlr->dma_tx)
936 tx_dev = ctlr->dma_tx->device->dev;
c37f45b5 937 else
8caab75f 938 tx_dev = ctlr->dev.parent;
c37f45b5 939
8caab75f
GU		 940 if (ctlr->dma_rx)
941 rx_dev = ctlr->dma_rx->device->dev;
c37f45b5 942 else
8caab75f 943 rx_dev = ctlr->dev.parent;
99adef31
MB		 944
945 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
8caab75f 946 if (!ctlr->can_dma(ctlr, msg->spi, xfer))
99adef31
MB		 947 continue;
948
8caab75f
GU		 949 spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
950 spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
99adef31
MB		 951 }
952
953 return 0;
954}
2de440f5 955#else /* !CONFIG_HAS_DMA */
8caab75f 956static inline int __spi_map_msg(struct spi_controller *ctlr,
2de440f5
GU		 957 struct spi_message *msg)
958{
959 return 0;
960}
961
8caab75f 962static inline int __spi_unmap_msg(struct spi_controller *ctlr,
4b786458 963 struct spi_message *msg)
2de440f5
GU		 964{
965 return 0;
966}
967#endif /* !CONFIG_HAS_DMA */
968
8caab75f 969static inline int spi_unmap_msg(struct spi_controller *ctlr,
4b786458
MS		 970 struct spi_message *msg)
971{
972 struct spi_transfer *xfer;
973
974 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
975 /*
976 * Restore the original value of tx_buf or rx_buf if they are
977 * NULL.
978 */
8caab75f 979 if (xfer->tx_buf == ctlr->dummy_tx)
4b786458 980 xfer->tx_buf = NULL;
8caab75f 981 if (xfer->rx_buf == ctlr->dummy_rx)
4b786458
MS		 982 xfer->rx_buf = NULL;
983 }
984
8caab75f 985 return __spi_unmap_msg(ctlr, msg);
4b786458
MS		 986}
987
8caab75f 988static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
2de440f5
GU		 989{
990 struct spi_transfer *xfer;
991 void *tmp;
992 unsigned int max_tx, max_rx;
993
8caab75f 994 if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
2de440f5
GU		 995 max_tx = 0;
996 max_rx = 0;
997
998 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
8caab75f 999 if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
2de440f5
GU		 1000 !xfer->tx_buf)
1001 max_tx = max(xfer->len, max_tx);
8caab75f 1002 if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
2de440f5
GU		 1003 !xfer->rx_buf)
1004 max_rx = max(xfer->len, max_rx);
1005 }
1006
1007 if (max_tx) {
8caab75f 1008 tmp = krealloc(ctlr->dummy_tx, max_tx,
2de440f5
GU		 1009 GFP_KERNEL | GFP_DMA);
1010 if (!tmp)
1011 return -ENOMEM;
8caab75f 1012 ctlr->dummy_tx = tmp;
2de440f5
GU		 1013 memset(tmp, 0, max_tx);
1014 }
1015
1016 if (max_rx) {
8caab75f 1017 tmp = krealloc(ctlr->dummy_rx, max_rx,
2de440f5
GU		 1018 GFP_KERNEL | GFP_DMA);
1019 if (!tmp)
1020 return -ENOMEM;
8caab75f 1021 ctlr->dummy_rx = tmp;
2de440f5
GU		 1022 }
1023
1024 if (max_tx || max_rx) {
1025 list_for_each_entry(xfer, &msg->transfers,
1026 transfer_list) {
1027 if (!xfer->tx_buf)
8caab75f 1028 xfer->tx_buf = ctlr->dummy_tx;
2de440f5 1029 if (!xfer->rx_buf)
8caab75f 1030 xfer->rx_buf = ctlr->dummy_rx;
2de440f5
GU		 1031 }
1032 }
1033 }
1034
8caab75f 1035 return __spi_map_msg(ctlr, msg);
2de440f5 1036}
99adef31 1037
810923f3
LR		 1038static int spi_transfer_wait(struct spi_controller *ctlr,
1039 struct spi_message *msg,
1040 struct spi_transfer *xfer)
1041{
1042 struct spi_statistics *statm = &ctlr->statistics;
1043 struct spi_statistics *stats = &msg->spi->statistics;
1044 unsigned long long ms = 1;
1045
1046 if (spi_controller_is_slave(ctlr)) {
1047 if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
1048 dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
1049 return -EINTR;
1050 }
1051 } else {
1052 ms = 8LL * 1000LL * xfer->len;
1053 do_div(ms, xfer->speed_hz);
1054 ms += ms + 200; /* some tolerance */
1055
1056 if (ms > UINT_MAX)
1057 ms = UINT_MAX;
1058
1059 ms = wait_for_completion_timeout(&ctlr->xfer_completion,
1060 msecs_to_jiffies(ms));
1061
1062 if (ms == 0) {
1063 SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
1064 SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
1065 dev_err(&msg->spi->dev,
1066 "SPI transfer timed out\n");
1067 return -ETIMEDOUT;
1068 }
1069 }
1070
1071 return 0;
1072}
1073
b158935f
MB		 1074/*
1075 * spi_transfer_one_message - Default implementation of transfer_one_message()
1076 *
1077 * This is a standard implementation of transfer_one_message() for
8ba811a7 1078 * drivers which implement a transfer_one() operation. It provides
b158935f
MB		 1079 * standard handling of delays and chip select management.
1080 */
8caab75f 1081static int spi_transfer_one_message(struct spi_controller *ctlr,
b158935f
MB		 1082 struct spi_message *msg)
1083{
1084 struct spi_transfer *xfer;
b158935f
MB		 1085 bool keep_cs = false;
1086 int ret = 0;
8caab75f 1087 struct spi_statistics *statm = &ctlr->statistics;
eca2ebc7 1088 struct spi_statistics *stats = &msg->spi->statistics;
b158935f
MB		 1089
1090 spi_set_cs(msg->spi, true);
1091
eca2ebc7
MS		 1092 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
1093 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
1094
b158935f
MB		 1095 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1096 trace_spi_transfer_start(msg, xfer);
1097
8caab75f
GU		 1098 spi_statistics_add_transfer_stats(statm, xfer, ctlr);
1099 spi_statistics_add_transfer_stats(stats, xfer, ctlr);
eca2ebc7 1100
38ec10f6 1101 if (xfer->tx_buf || xfer->rx_buf) {
8caab75f 1102 reinit_completion(&ctlr->xfer_completion);
b158935f 1103
8caab75f 1104 ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
38ec10f6 1105 if (ret < 0) {
eca2ebc7
MS		 1106 SPI_STATISTICS_INCREMENT_FIELD(statm,
1107 errors);
1108 SPI_STATISTICS_INCREMENT_FIELD(stats,
1109 errors);
38ec10f6
MB		 1110 dev_err(&msg->spi->dev,
1111 "SPI transfer failed: %d\n", ret);
1112 goto out;
1113 }
b158935f 1114
d57e7960
MB		 1115 if (ret > 0) {
1116 ret = spi_transfer_wait(ctlr, msg, xfer);
1117 if (ret < 0)
1118 msg->status = ret;
1119 }
38ec10f6
MB		 1120 } else {
1121 if (xfer->len)
1122 dev_err(&msg->spi->dev,
1123 "Bufferless transfer has length %u\n",
1124 xfer->len);
13a42798 1125 }
b158935f
MB		 1126
1127 trace_spi_transfer_stop(msg, xfer);
1128
1129 if (msg->status != -EINPROGRESS)
1130 goto out;
1131
8244bd3a
DK		 1132 if (xfer->delay_usecs) {
1133 u16 us = xfer->delay_usecs;
1134
1135 if (us <= 10)
1136 udelay(us);
1137 else
1138 usleep_range(us, us + DIV_ROUND_UP(us, 10));
1139 }
b158935f
MB		 1140
1141 if (xfer->cs_change) {
1142 if (list_is_last(&xfer->transfer_list,
1143 &msg->transfers)) {
1144 keep_cs = true;
1145 } else {
0b73aa63
MB		 1146 spi_set_cs(msg->spi, false);
1147 udelay(10);
1148 spi_set_cs(msg->spi, true);
b158935f
MB		 1149 }
1150 }
1151
1152 msg->actual_length += xfer->len;
1153 }
1154
1155out:
1156 if (ret != 0 || !keep_cs)
1157 spi_set_cs(msg->spi, false);
1158
1159 if (msg->status == -EINPROGRESS)
1160 msg->status = ret;
1161
8caab75f
GU		 1162 if (msg->status && ctlr->handle_err)
1163 ctlr->handle_err(ctlr, msg);
b716c4ff 1164
8caab75f 1165 spi_res_release(ctlr, msg);
d780c371 1166
8caab75f 1167 spi_finalize_current_message(ctlr);
b158935f
MB		 1168
1169 return ret;
1170}
1171
1172/**
1173 * spi_finalize_current_transfer - report completion of a transfer
8caab75f 1174 * @ctlr: the controller reporting completion
b158935f
MB		 1175 *
1176 * Called by SPI drivers using the core transfer_one_message()
1177 * implementation to notify it that the current interrupt driven
9e8f4882 1178 * transfer has finished and the next one may be scheduled.
b158935f 1179 */
8caab75f 1180void spi_finalize_current_transfer(struct spi_controller *ctlr)
b158935f 1181{
8caab75f 1182 complete(&ctlr->xfer_completion);
b158935f
MB		 1183}
1184EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1185
ffbbdd21 1186/**
fc9e0f71 1187 * __spi_pump_messages - function which processes spi message queue
8caab75f 1188 * @ctlr: controller to process queue for
fc9e0f71 1189 * @in_kthread: true if we are in the context of the message pump thread
ffbbdd21
LW		 1190 *
1191 * This function checks if there is any spi message in the queue that
1192 * needs processing and if so call out to the driver to initialize hardware
1193 * and transfer each message.
1194 *
0461a414
MB		 1195 * Note that it is called both from the kthread itself and also from
1196 * inside spi_sync(); the queue extraction handling at the top of the
1197 * function should deal with this safely.
ffbbdd21 1198 */
8caab75f 1199static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
ffbbdd21 1200{
ffbbdd21
LW		 1201 unsigned long flags;
1202 bool was_busy = false;
1203 int ret;
1204
983aee5d 1205 /* Lock queue */
8caab75f 1206 spin_lock_irqsave(&ctlr->queue_lock, flags);
983aee5d
MB		 1207
1208 /* Make sure we are not already running a message */
8caab75f
GU		 1209 if (ctlr->cur_msg) {
1210 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
983aee5d
MB		 1211 return;
1212 }
1213
0461a414 1214 /* If another context is idling the device then defer */
8caab75f
GU		 1215 if (ctlr->idling) {
1216 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1217 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
0461a414
MB		 1218 return;
1219 }
1220
983aee5d 1221 /* Check if the queue is idle */
8caab75f
GU		 1222 if (list_empty(&ctlr->queue) || !ctlr->running) {
1223 if (!ctlr->busy) {
1224 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
b0b36b86 1225 return;
ffbbdd21 1226 }
fc9e0f71
MB		 1227
1228 /* Only do teardown in the thread */
1229 if (!in_kthread) {
8caab75f
GU		 1230 kthread_queue_work(&ctlr->kworker,
1231 &ctlr->pump_messages);
1232 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
fc9e0f71
MB		 1233 return;
1234 }
1235
8caab75f
GU		 1236 ctlr->busy = false;
1237 ctlr->idling = true;
1238 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
1239
1240 kfree(ctlr->dummy_rx);
1241 ctlr->dummy_rx = NULL;
1242 kfree(ctlr->dummy_tx);
1243 ctlr->dummy_tx = NULL;
1244 if (ctlr->unprepare_transfer_hardware &&
1245 ctlr->unprepare_transfer_hardware(ctlr))
1246 dev_err(&ctlr->dev,
b0b36b86 1247 "failed to unprepare transfer hardware\n");
8caab75f
GU		 1248 if (ctlr->auto_runtime_pm) {
1249 pm_runtime_mark_last_busy(ctlr->dev.parent);
1250 pm_runtime_put_autosuspend(ctlr->dev.parent);
49834de2 1251 }
8caab75f 1252 trace_spi_controller_idle(ctlr);
ffbbdd21 1253
8caab75f
GU		 1254 spin_lock_irqsave(&ctlr->queue_lock, flags);
1255 ctlr->idling = false;
1256 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1257 return;
1258 }
ffbbdd21 1259
ffbbdd21 1260 /* Extract head of queue */
8caab75f
GU		 1261 ctlr->cur_msg =
1262 list_first_entry(&ctlr->queue, struct spi_message, queue);
ffbbdd21 1263
8caab75f
GU		 1264 list_del_init(&ctlr->cur_msg->queue);
1265 if (ctlr->busy)
ffbbdd21
LW		 1266 was_busy = true;
1267 else
8caab75f
GU		 1268 ctlr->busy = true;
1269 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21 1270
8caab75f 1271 mutex_lock(&ctlr->io_mutex);
ef4d96ec 1272
8caab75f
GU		 1273 if (!was_busy && ctlr->auto_runtime_pm) {
1274 ret = pm_runtime_get_sync(ctlr->dev.parent);
49834de2 1275 if (ret < 0) {
7e48e23a 1276 pm_runtime_put_noidle(ctlr->dev.parent);
8caab75f 1277 dev_err(&ctlr->dev, "Failed to power device: %d\n",
49834de2 1278 ret);
8caab75f 1279 mutex_unlock(&ctlr->io_mutex);
49834de2
MB		 1280 return;
1281 }
1282 }
1283
56ec1978 1284 if (!was_busy)
8caab75f 1285 trace_spi_controller_busy(ctlr);
56ec1978 1286
8caab75f
GU		 1287 if (!was_busy && ctlr->prepare_transfer_hardware) {
1288 ret = ctlr->prepare_transfer_hardware(ctlr);
ffbbdd21 1289 if (ret) {
8caab75f 1290 dev_err(&ctlr->dev,
ffbbdd21 1291 "failed to prepare transfer hardware\n");
49834de2 1292
8caab75f
GU		 1293 if (ctlr->auto_runtime_pm)
1294 pm_runtime_put(ctlr->dev.parent);
1295 mutex_unlock(&ctlr->io_mutex);
ffbbdd21
LW		 1296 return;
1297 }
1298 }
1299
8caab75f 1300 trace_spi_message_start(ctlr->cur_msg);
56ec1978 1301
8caab75f
GU		 1302 if (ctlr->prepare_message) {
1303 ret = ctlr->prepare_message(ctlr, ctlr->cur_msg);
2841a5fc 1304 if (ret) {
8caab75f
GU		 1305 dev_err(&ctlr->dev, "failed to prepare message: %d\n",
1306 ret);
1307 ctlr->cur_msg->status = ret;
1308 spi_finalize_current_message(ctlr);
49023d2e 1309 goto out;
2841a5fc 1310 }
8caab75f 1311 ctlr->cur_msg_prepared = true;
2841a5fc
MB		 1312 }
1313
8caab75f 1314 ret = spi_map_msg(ctlr, ctlr->cur_msg);
99adef31 1315 if (ret) {
8caab75f
GU		 1316 ctlr->cur_msg->status = ret;
1317 spi_finalize_current_message(ctlr);
49023d2e 1318 goto out;
99adef31
MB		 1319 }
1320
8caab75f 1321 ret = ctlr->transfer_one_message(ctlr, ctlr->cur_msg);
ffbbdd21 1322 if (ret) {
8caab75f 1323 dev_err(&ctlr->dev,
1f802f82 1324 "failed to transfer one message from queue\n");
49023d2e 1325 goto out;
ffbbdd21 1326 }
49023d2e
JH		 1327
1328out:
8caab75f 1329 mutex_unlock(&ctlr->io_mutex);
62826970
MB		 1330
1331 /* Prod the scheduler in case transfer_one() was busy waiting */
49023d2e
JH		 1332 if (!ret)
1333 cond_resched();
ffbbdd21
LW		 1334}
1335
fc9e0f71
MB		 1336/**
1337 * spi_pump_messages - kthread work function which processes spi message queue
8caab75f 1338 * @work: pointer to kthread work struct contained in the controller struct
fc9e0f71
MB		 1339 */
1340static void spi_pump_messages(struct kthread_work *work)
1341{
8caab75f
GU		 1342 struct spi_controller *ctlr =
1343 container_of(work, struct spi_controller, pump_messages);
fc9e0f71 1344
8caab75f 1345 __spi_pump_messages(ctlr, true);
fc9e0f71
MB		 1346}
1347
8caab75f 1348static int spi_init_queue(struct spi_controller *ctlr)
ffbbdd21
LW		 1349{
1350 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1351
8caab75f
GU		 1352 ctlr->running = false;
1353 ctlr->busy = false;
ffbbdd21 1354
8caab75f
GU		 1355 kthread_init_worker(&ctlr->kworker);
1356 ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
1357 "%s", dev_name(&ctlr->dev));
1358 if (IS_ERR(ctlr->kworker_task)) {
1359 dev_err(&ctlr->dev, "failed to create message pump task\n");
1360 return PTR_ERR(ctlr->kworker_task);
ffbbdd21 1361 }
8caab75f 1362 kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
ffbbdd21
LW		 1363
1364 /*
8caab75f 1365 * Controller config will indicate if this controller should run the
ffbbdd21
LW		 1366 * message pump with high (realtime) priority to reduce the transfer
1367 * latency on the bus by minimising the delay between a transfer
1368 * request and the scheduling of the message pump thread. Without this
1369 * setting the message pump thread will remain at default priority.
1370 */
8caab75f
GU		 1371 if (ctlr->rt) {
1372 dev_info(&ctlr->dev,
ffbbdd21 1373 "will run message pump with realtime priority\n");
8caab75f 1374 sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, &param);
ffbbdd21
LW		 1375 }
1376
1377 return 0;
1378}
1379
1380/**
1381 * spi_get_next_queued_message() - called by driver to check for queued
1382 * messages
8caab75f 1383 * @ctlr: the controller to check for queued messages
ffbbdd21
LW		 1384 *
1385 * If there are more messages in the queue, the next message is returned from
1386 * this call.
97d56dc6
JMC		 1387 *
1388 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21 1389 */
8caab75f 1390struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
ffbbdd21
LW		 1391{
1392 struct spi_message *next;
1393 unsigned long flags;
1394
1395 /* get a pointer to the next message, if any */
8caab75f
GU		 1396 spin_lock_irqsave(&ctlr->queue_lock, flags);
1397 next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
1cfd97f9 1398 queue);
8caab75f 1399 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1400
1401 return next;
1402}
1403EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1404
1405/**
1406 * spi_finalize_current_message() - the current message is complete
8caab75f 1407 * @ctlr: the controller to return the message to
ffbbdd21
LW		 1408 *
1409 * Called by the driver to notify the core that the message in the front of the
1410 * queue is complete and can be removed from the queue.
1411 */
8caab75f 1412void spi_finalize_current_message(struct spi_controller *ctlr)
ffbbdd21
LW		 1413{
1414 struct spi_message *mesg;
1415 unsigned long flags;
2841a5fc 1416 int ret;
ffbbdd21 1417
8caab75f
GU		 1418 spin_lock_irqsave(&ctlr->queue_lock, flags);
1419 mesg = ctlr->cur_msg;
1420 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21 1421
8caab75f 1422 spi_unmap_msg(ctlr, mesg);
99adef31 1423
8caab75f
GU		 1424 if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
1425 ret = ctlr->unprepare_message(ctlr, mesg);
2841a5fc 1426 if (ret) {
8caab75f
GU		 1427 dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
1428 ret);
2841a5fc
MB		 1429 }
1430 }
391949b6 1431
8caab75f
GU		 1432 spin_lock_irqsave(&ctlr->queue_lock, flags);
1433 ctlr->cur_msg = NULL;
1434 ctlr->cur_msg_prepared = false;
1435 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
1436 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
8e76ef88
MS		 1437
1438 trace_spi_message_done(mesg);
2841a5fc 1439
ffbbdd21
LW		 1440 mesg->state = NULL;
1441 if (mesg->complete)
1442 mesg->complete(mesg->context);
1443}
1444EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1445
8caab75f 1446static int spi_start_queue(struct spi_controller *ctlr)
ffbbdd21
LW		 1447{
1448 unsigned long flags;
1449
8caab75f 1450 spin_lock_irqsave(&ctlr->queue_lock, flags);
ffbbdd21 1451
8caab75f
GU		 1452 if (ctlr->running || ctlr->busy) {
1453 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1454 return -EBUSY;
1455 }
1456
8caab75f
GU		 1457 ctlr->running = true;
1458 ctlr->cur_msg = NULL;
1459 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21 1460
8caab75f 1461 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
ffbbdd21
LW		 1462
1463 return 0;
1464}
1465
8caab75f 1466static int spi_stop_queue(struct spi_controller *ctlr)
ffbbdd21
LW		 1467{
1468 unsigned long flags;
1469 unsigned limit = 500;
1470 int ret = 0;
1471
8caab75f 1472 spin_lock_irqsave(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1473
1474 /*
1475 * This is a bit lame, but is optimized for the common execution path.
8caab75f 1476 * A wait_queue on the ctlr->busy could be used, but then the common
ffbbdd21
LW		 1477 * execution path (pump_messages) would be required to call wake_up or
1478 * friends on every SPI message. Do this instead.
1479 */
8caab75f
GU		 1480 while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
1481 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
f97b26b0 1482 usleep_range(10000, 11000);
8caab75f 1483 spin_lock_irqsave(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1484 }
1485
8caab75f 1486 if (!list_empty(&ctlr->queue) || ctlr->busy)
ffbbdd21
LW		 1487 ret = -EBUSY;
1488 else
8caab75f 1489 ctlr->running = false;
ffbbdd21 1490
8caab75f 1491 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1492
1493 if (ret) {
8caab75f 1494 dev_warn(&ctlr->dev, "could not stop message queue\n");
ffbbdd21
LW		 1495 return ret;
1496 }
1497 return ret;
1498}
1499
8caab75f 1500static int spi_destroy_queue(struct spi_controller *ctlr)
ffbbdd21
LW		 1501{
1502 int ret;
1503
8caab75f 1504 ret = spi_stop_queue(ctlr);
ffbbdd21
LW		 1505
1506 /*
3989144f 1507 * kthread_flush_worker will block until all work is done.
ffbbdd21
LW		 1508 * If the reason that stop_queue timed out is that the work will never
1509 * finish, then it does no good to call flush/stop thread, so
1510 * return anyway.
1511 */
1512 if (ret) {
8caab75f 1513 dev_err(&ctlr->dev, "problem destroying queue\n");
ffbbdd21
LW		 1514 return ret;
1515 }
1516
8caab75f
GU		 1517 kthread_flush_worker(&ctlr->kworker);
1518 kthread_stop(ctlr->kworker_task);
ffbbdd21
LW		 1519
1520 return 0;
1521}
1522
0461a414
MB		 1523static int __spi_queued_transfer(struct spi_device *spi,
1524 struct spi_message *msg,
1525 bool need_pump)
ffbbdd21 1526{
8caab75f 1527 struct spi_controller *ctlr = spi->controller;
ffbbdd21
LW		 1528 unsigned long flags;
1529
8caab75f 1530 spin_lock_irqsave(&ctlr->queue_lock, flags);
ffbbdd21 1531
8caab75f
GU		 1532 if (!ctlr->running) {
1533 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1534 return -ESHUTDOWN;
1535 }
1536 msg->actual_length = 0;
1537 msg->status = -EINPROGRESS;
1538
8caab75f
GU		 1539 list_add_tail(&msg->queue, &ctlr->queue);
1540 if (!ctlr->busy && need_pump)
1541 kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
ffbbdd21 1542
8caab75f 1543 spin_unlock_irqrestore(&ctlr->queue_lock, flags);
ffbbdd21
LW		 1544 return 0;
1545}
1546
0461a414
MB		 1547/**
1548 * spi_queued_transfer - transfer function for queued transfers
1549 * @spi: spi device which is requesting transfer
1550 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1551 *
1552 * Return: zero on success, else a negative error code.
0461a414
MB		 1553 */
1554static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1555{
1556 return __spi_queued_transfer(spi, msg, true);
1557}
1558
8caab75f 1559static int spi_controller_initialize_queue(struct spi_controller *ctlr)
ffbbdd21
LW		 1560{
1561 int ret;
1562
8caab75f
GU		 1563 ctlr->transfer = spi_queued_transfer;
1564 if (!ctlr->transfer_one_message)
1565 ctlr->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1566
1567 /* Initialize and start queue */
8caab75f 1568 ret = spi_init_queue(ctlr);
ffbbdd21 1569 if (ret) {
8caab75f 1570 dev_err(&ctlr->dev, "problem initializing queue\n");
ffbbdd21
LW		 1571 goto err_init_queue;
1572 }
8caab75f
GU		 1573 ctlr->queued = true;
1574 ret = spi_start_queue(ctlr);
ffbbdd21 1575 if (ret) {
8caab75f 1576 dev_err(&ctlr->dev, "problem starting queue\n");
ffbbdd21
LW		 1577 goto err_start_queue;
1578 }
1579
1580 return 0;
1581
1582err_start_queue:
8caab75f 1583 spi_destroy_queue(ctlr);
c3676d5c 1584err_init_queue:
ffbbdd21
LW		 1585 return ret;
1586}
1587
988f259b
BB		 1588/**
1589 * spi_flush_queue - Send all pending messages in the queue from the callers'
1590 * context
1591 * @ctlr: controller to process queue for
1592 *
1593 * This should be used when one wants to ensure all pending messages have been
1594 * sent before doing something. Is used by the spi-mem code to make sure SPI
1595 * memory operations do not preempt regular SPI transfers that have been queued
1596 * before the spi-mem operation.
1597 */
1598void spi_flush_queue(struct spi_controller *ctlr)
1599{
1600 if (ctlr->transfer == spi_queued_transfer)
1601 __spi_pump_messages(ctlr, false);
1602}
1603
ffbbdd21
LW		 1604/*-------------------------------------------------------------------------*/
1605
7cb94361 1606#if defined(CONFIG_OF)
8caab75f 1607static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
c2e51ac3 1608 struct device_node *nc)
aff5e3f8 1609{
aff5e3f8 1610 u32 value;
c2e51ac3 1611 int rc;
aff5e3f8 1612
aff5e3f8 1613 /* Mode (clock phase/polarity/etc.) */
e0bcb680 1614 if (of_property_read_bool(nc, "spi-cpha"))
aff5e3f8 1615 spi->mode |= SPI_CPHA;
e0bcb680 1616 if (of_property_read_bool(nc, "spi-cpol"))
aff5e3f8 1617 spi->mode |= SPI_CPOL;
e0bcb680 1618 if (of_property_read_bool(nc, "spi-cs-high"))
aff5e3f8 1619 spi->mode |= SPI_CS_HIGH;
e0bcb680 1620 if (of_property_read_bool(nc, "spi-3wire"))
aff5e3f8 1621 spi->mode |= SPI_3WIRE;
e0bcb680 1622 if (of_property_read_bool(nc, "spi-lsb-first"))
aff5e3f8
PA		 1623 spi->mode |= SPI_LSB_FIRST;
1624
1625 /* Device DUAL/QUAD mode */
1626 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1627 switch (value) {
1628 case 1:
1629 break;
1630 case 2:
1631 spi->mode |= SPI_TX_DUAL;
1632 break;
1633 case 4:
1634 spi->mode |= SPI_TX_QUAD;
1635 break;
6b03061f
YNG		 1636 case 8:
1637 spi->mode |= SPI_TX_OCTAL;
1638 break;
aff5e3f8 1639 default:
8caab75f 1640 dev_warn(&ctlr->dev,
aff5e3f8
PA		 1641 "spi-tx-bus-width %d not supported\n",
1642 value);
1643 break;
1644 }
1645 }
1646
1647 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1648 switch (value) {
1649 case 1:
1650 break;
1651 case 2:
1652 spi->mode |= SPI_RX_DUAL;
1653 break;
1654 case 4:
1655 spi->mode |= SPI_RX_QUAD;
1656 break;
6b03061f
YNG		 1657 case 8:
1658 spi->mode |= SPI_RX_OCTAL;
1659 break;
aff5e3f8 1660 default:
8caab75f 1661 dev_warn(&ctlr->dev,
aff5e3f8
PA		 1662 "spi-rx-bus-width %d not supported\n",
1663 value);
1664 break;
1665 }
1666 }
1667
8caab75f 1668 if (spi_controller_is_slave(ctlr)) {
194276b0 1669 if (!of_node_name_eq(nc, "slave")) {
25c56c88
RH		 1670 dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
1671 nc);
6c364062
GU		 1672 return -EINVAL;
1673 }
1674 return 0;
1675 }
1676
1677 /* Device address */
1678 rc = of_property_read_u32(nc, "reg", &value);
1679 if (rc) {
25c56c88
RH		 1680 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
1681 nc, rc);
6c364062
GU		 1682 return rc;
1683 }
1684 spi->chip_select = value;
1685
aff5e3f8
PA		 1686 /* Device speed */
1687 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1688 if (rc) {
8caab75f 1689 dev_err(&ctlr->dev,
25c56c88 1690 "%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
c2e51ac3 1691 return rc;
aff5e3f8
PA		 1692 }
1693 spi->max_speed_hz = value;
1694
c2e51ac3
GU		 1695 return 0;
1696}
1697
1698static struct spi_device *
8caab75f 1699of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
c2e51ac3
GU		 1700{
1701 struct spi_device *spi;
1702 int rc;
1703
1704 /* Alloc an spi_device */
8caab75f 1705 spi = spi_alloc_device(ctlr);
c2e51ac3 1706 if (!spi) {
25c56c88 1707 dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
c2e51ac3
GU		 1708 rc = -ENOMEM;
1709 goto err_out;
1710 }
1711
1712 /* Select device driver */
1713 rc = of_modalias_node(nc, spi->modalias,
1714 sizeof(spi->modalias));
1715 if (rc < 0) {
25c56c88 1716 dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
c2e51ac3
GU		 1717 goto err_out;
1718 }
1719
8caab75f 1720 rc = of_spi_parse_dt(ctlr, spi, nc);
c2e51ac3
GU		 1721 if (rc)
1722 goto err_out;
1723
aff5e3f8
PA		 1724 /* Store a pointer to the node in the device structure */
1725 of_node_get(nc);
1726 spi->dev.of_node = nc;
1727
1728 /* Register the new device */
aff5e3f8
PA		 1729 rc = spi_add_device(spi);
1730 if (rc) {
25c56c88 1731 dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
8324147f 1732 goto err_of_node_put;
aff5e3f8
PA		 1733 }
1734
1735 return spi;
1736
8324147f
JH		 1737err_of_node_put:
1738 of_node_put(nc);
aff5e3f8
PA		 1739err_out:
1740 spi_dev_put(spi);
1741 return ERR_PTR(rc);
1742}
1743
d57a4282
GL		 1744/**
1745 * of_register_spi_devices() - Register child devices onto the SPI bus
8caab75f 1746 * @ctlr: Pointer to spi_controller device
d57a4282 1747 *
6c364062
GU		 1748 * Registers an spi_device for each child node of controller node which
1749 * represents a valid SPI slave.
d57a4282 1750 */
8caab75f 1751static void of_register_spi_devices(struct spi_controller *ctlr)
d57a4282
GL		 1752{
1753 struct spi_device *spi;
1754 struct device_node *nc;
d57a4282 1755
8caab75f 1756 if (!ctlr->dev.of_node)
d57a4282
GL		 1757 return;
1758
8caab75f 1759 for_each_available_child_of_node(ctlr->dev.of_node, nc) {
bd6c1644
GU		 1760 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1761 continue;
8caab75f 1762 spi = of_register_spi_device(ctlr, nc);
e0af98a7 1763 if (IS_ERR(spi)) {
8caab75f 1764 dev_warn(&ctlr->dev,
25c56c88 1765 "Failed to create SPI device for %pOF\n", nc);
e0af98a7
RR		 1766 of_node_clear_flag(nc, OF_POPULATED);
1767 }
d57a4282
GL		 1768 }
1769}
1770#else
8caab75f 1771static void of_register_spi_devices(struct spi_controller *ctlr) { }
d57a4282
GL		 1772#endif
1773
64bee4d2 1774#ifdef CONFIG_ACPI
8a2e487e
LW		 1775static void acpi_spi_parse_apple_properties(struct spi_device *spi)
1776{
1777 struct acpi_device *dev = ACPI_COMPANION(&spi->dev);
1778 const union acpi_object *obj;
1779
1780 if (!x86_apple_machine)
1781 return;
1782
1783 if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
1784 && obj->buffer.length >= 4)
1785 spi->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
1786
1787 if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
1788 && obj->buffer.length == 8)
1789 spi->bits_per_word = *(u64 *)obj->buffer.pointer;
1790
1791 if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
1792 && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
1793 spi->mode |= SPI_LSB_FIRST;
1794
1795 if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
1796 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1797 spi->mode |= SPI_CPOL;
1798
1799 if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
1800 && obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
1801 spi->mode |= SPI_CPHA;
1802}
1803
64bee4d2
MW		 1804static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1805{
1806 struct spi_device *spi = data;
8caab75f 1807 struct spi_controller *ctlr = spi->controller;
64bee4d2
MW		 1808
1809 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1810 struct acpi_resource_spi_serialbus *sb;
1811
1812 sb = &ares->data.spi_serial_bus;
1813 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
a0a90718
MW		 1814 /*
1815 * ACPI DeviceSelection numbering is handled by the
1816 * host controller driver in Windows and can vary
1817 * from driver to driver. In Linux we always expect
1818 * 0 .. max - 1 so we need to ask the driver to
1819 * translate between the two schemes.
1820 */
8caab75f
GU		 1821 if (ctlr->fw_translate_cs) {
1822 int cs = ctlr->fw_translate_cs(ctlr,
a0a90718
MW		 1823 sb->device_selection);
1824 if (cs < 0)
1825 return cs;
1826 spi->chip_select = cs;
1827 } else {
1828 spi->chip_select = sb->device_selection;
1829 }
1830
64bee4d2
MW		 1831 spi->max_speed_hz = sb->connection_speed;
1832
1833 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1834 spi->mode |= SPI_CPHA;
1835 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1836 spi->mode |= SPI_CPOL;
1837 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1838 spi->mode |= SPI_CS_HIGH;
1839 }
1840 } else if (spi->irq < 0) {
1841 struct resource r;
1842
1843 if (acpi_dev_resource_interrupt(ares, 0, &r))
1844 spi->irq = r.start;
1845 }
1846
1847 /* Always tell the ACPI core to skip this resource */
1848 return 1;
1849}
1850
8caab75f 1851static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
7f24467f 1852 struct acpi_device *adev)
64bee4d2 1853{
64bee4d2 1854 struct list_head resource_list;
64bee4d2
MW		 1855 struct spi_device *spi;
1856 int ret;
1857
7f24467f
OP		 1858 if (acpi_bus_get_status(adev) || !adev->status.present ||
1859 acpi_device_enumerated(adev))
64bee4d2
MW		 1860 return AE_OK;
1861
8caab75f 1862 spi = spi_alloc_device(ctlr);
64bee4d2 1863 if (!spi) {
8caab75f 1864 dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
64bee4d2
MW		 1865 dev_name(&adev->dev));
1866 return AE_NO_MEMORY;
1867 }
1868
7b199811 1869 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1870 spi->irq = -1;
1871
1872 INIT_LIST_HEAD(&resource_list);
1873 ret = acpi_dev_get_resources(adev, &resource_list,
1874 acpi_spi_add_resource, spi);
1875 acpi_dev_free_resource_list(&resource_list);
1876
8a2e487e
LW		 1877 acpi_spi_parse_apple_properties(spi);
1878
64bee4d2
MW		 1879 if (ret < 0 || !spi->max_speed_hz) {
1880 spi_dev_put(spi);
1881 return AE_OK;
1882 }
1883
0c6543f6
DD		 1884 acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
1885 sizeof(spi->modalias));
1886
33ada67d
CR		 1887 if (spi->irq < 0)
1888 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1889
7f24467f
OP		 1890 acpi_device_set_enumerated(adev);
1891
33cf00e5 1892 adev->power.flags.ignore_parent = true;
64bee4d2 1893 if (spi_add_device(spi)) {
33cf00e5 1894 adev->power.flags.ignore_parent = false;
8caab75f 1895 dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
64bee4d2
MW		 1896 dev_name(&adev->dev));
1897 spi_dev_put(spi);
1898 }
1899
1900 return AE_OK;
1901}
1902
7f24467f
OP		 1903static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1904 void *data, void **return_value)
1905{
8caab75f 1906 struct spi_controller *ctlr = data;
7f24467f
OP		 1907 struct acpi_device *adev;
1908
1909 if (acpi_bus_get_device(handle, &adev))
1910 return AE_OK;
1911
8caab75f 1912 return acpi_register_spi_device(ctlr, adev);
7f24467f
OP		 1913}
1914
8caab75f 1915static void acpi_register_spi_devices(struct spi_controller *ctlr)
64bee4d2
MW		 1916{
1917 acpi_status status;
1918 acpi_handle handle;
1919
8caab75f 1920 handle = ACPI_HANDLE(ctlr->dev.parent);
64bee4d2
MW		 1921 if (!handle)
1922 return;
1923
1924 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
8caab75f 1925 acpi_spi_add_device, NULL, ctlr, NULL);
64bee4d2 1926 if (ACPI_FAILURE(status))
8caab75f 1927 dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
64bee4d2
MW		 1928}
1929#else
8caab75f 1930static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
64bee4d2
MW		 1931#endif /* CONFIG_ACPI */
1932
8caab75f 1933static void spi_controller_release(struct device *dev)
8ae12a0d 1934{
8caab75f 1935 struct spi_controller *ctlr;
8ae12a0d 1936
8caab75f
GU		 1937 ctlr = container_of(dev, struct spi_controller, dev);
1938 kfree(ctlr);
8ae12a0d
DB		 1939}
1940
1941static struct class spi_master_class = {
1942 .name = "spi_master",
1943 .owner = THIS_MODULE,
8caab75f 1944 .dev_release = spi_controller_release,
eca2ebc7 1945 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1946};
1947
6c364062
GU		 1948#ifdef CONFIG_SPI_SLAVE
1949/**
1950 * spi_slave_abort - abort the ongoing transfer request on an SPI slave
1951 * controller
1952 * @spi: device used for the current transfer
1953 */
1954int spi_slave_abort(struct spi_device *spi)
1955{
8caab75f 1956 struct spi_controller *ctlr = spi->controller;
6c364062 1957
8caab75f
GU		 1958 if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
1959 return ctlr->slave_abort(ctlr);
6c364062
GU		 1960
1961 return -ENOTSUPP;
1962}
1963EXPORT_SYMBOL_GPL(spi_slave_abort);
1964
1965static int match_true(struct device *dev, void *data)
1966{
1967 return 1;
1968}
1969
1970static ssize_t spi_slave_show(struct device *dev,
1971 struct device_attribute *attr, char *buf)
1972{
8caab75f
GU		 1973 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1974 dev);
6c364062
GU		 1975 struct device *child;
1976
1977 child = device_find_child(&ctlr->dev, NULL, match_true);
1978 return sprintf(buf, "%s\n",
1979 child ? to_spi_device(child)->modalias : NULL);
1980}
1981
1982static ssize_t spi_slave_store(struct device *dev,
1983 struct device_attribute *attr, const char *buf,
1984 size_t count)
1985{
8caab75f
GU		 1986 struct spi_controller *ctlr = container_of(dev, struct spi_controller,
1987 dev);
6c364062
GU		 1988 struct spi_device *spi;
1989 struct device *child;
1990 char name[32];
1991 int rc;
1992
1993 rc = sscanf(buf, "%31s", name);
1994 if (rc != 1 || !name[0])
1995 return -EINVAL;
1996
1997 child = device_find_child(&ctlr->dev, NULL, match_true);
1998 if (child) {
1999 /* Remove registered slave */
2000 device_unregister(child);
2001 put_device(child);
2002 }
2003
2004 if (strcmp(name, "(null)")) {
2005 /* Register new slave */
2006 spi = spi_alloc_device(ctlr);
2007 if (!spi)
2008 return -ENOMEM;
2009
2010 strlcpy(spi->modalias, name, sizeof(spi->modalias));
2011
2012 rc = spi_add_device(spi);
2013 if (rc) {
2014 spi_dev_put(spi);
2015 return rc;
2016 }
2017 }
2018
2019 return count;
2020}
2021
2022static DEVICE_ATTR(slave, 0644, spi_slave_show, spi_slave_store);
2023
2024static struct attribute *spi_slave_attrs[] = {
2025 &dev_attr_slave.attr,
2026 NULL,
2027};
2028
2029static const struct attribute_group spi_slave_group = {
2030 .attrs = spi_slave_attrs,
2031};
2032
2033static const struct attribute_group *spi_slave_groups[] = {
8caab75f 2034 &spi_controller_statistics_group,
6c364062
GU		 2035 &spi_slave_group,
2036 NULL,
2037};
2038
2039static struct class spi_slave_class = {
2040 .name = "spi_slave",
2041 .owner = THIS_MODULE,
8caab75f 2042 .dev_release = spi_controller_release,
6c364062
GU		 2043 .dev_groups = spi_slave_groups,
2044};
2045#else
2046extern struct class spi_slave_class; /* dummy */
2047#endif
8ae12a0d
DB		 2048
2049/**
6c364062 2050 * __spi_alloc_controller - allocate an SPI master or slave controller
8ae12a0d 2051 * @dev: the controller, possibly using the platform_bus
33e34dc6 2052 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 2053 * memory is in the driver_data field of the returned device,
8caab75f 2054 * accessible with spi_controller_get_devdata().
6c364062
GU		 2055 * @slave: flag indicating whether to allocate an SPI master (false) or SPI
2056 * slave (true) controller
33e34dc6 2057 * Context: can sleep
8ae12a0d 2058 *
6c364062 2059 * This call is used only by SPI controller drivers, which are the
8ae12a0d 2060 * only ones directly touching chip registers. It's how they allocate
8caab75f 2061 * an spi_controller structure, prior to calling spi_register_controller().
8ae12a0d 2062 *
97d56dc6 2063 * This must be called from context that can sleep.
8ae12a0d 2064 *
6c364062 2065 * The caller is responsible for assigning the bus number and initializing the
8caab75f
GU		 2066 * controller's methods before calling spi_register_controller(); and (after
2067 * errors adding the device) calling spi_controller_put() to prevent a memory
2068 * leak.
97d56dc6 2069 *
6c364062 2070 * Return: the SPI controller structure on success, else NULL.
8ae12a0d 2071 */
8caab75f
GU		 2072struct spi_controller *__spi_alloc_controller(struct device *dev,
2073 unsigned int size, bool slave)
8ae12a0d 2074{
8caab75f 2075 struct spi_controller *ctlr;
8ae12a0d 2076
0c868461
DB		 2077 if (!dev)
2078 return NULL;
2079
8caab75f
GU		 2080 ctlr = kzalloc(size + sizeof(*ctlr), GFP_KERNEL);
2081 if (!ctlr)
8ae12a0d
DB		 2082 return NULL;
2083
8caab75f
GU		 2084 device_initialize(&ctlr->dev);
2085 ctlr->bus_num = -1;
2086 ctlr->num_chipselect = 1;
2087 ctlr->slave = slave;
6c364062 2088 if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
8caab75f 2089 ctlr->dev.class = &spi_slave_class;
6c364062 2090 else
8caab75f
GU		 2091 ctlr->dev.class = &spi_master_class;
2092 ctlr->dev.parent = dev;
2093 pm_suspend_ignore_children(&ctlr->dev, true);
2094 spi_controller_set_devdata(ctlr, &ctlr[1]);
8ae12a0d 2095
8caab75f 2096 return ctlr;
8ae12a0d 2097}
6c364062 2098EXPORT_SYMBOL_GPL(__spi_alloc_controller);
8ae12a0d 2099
74317984 2100#ifdef CONFIG_OF
8caab75f 2101static int of_spi_register_master(struct spi_controller *ctlr)
74317984 2102{
e80beb27 2103 int nb, i, *cs;
8caab75f 2104 struct device_node *np = ctlr->dev.of_node;
74317984
JCPV		 2105
2106 if (!np)
2107 return 0;
2108
2109 nb = of_gpio_named_count(np, "cs-gpios");
8caab75f 2110 ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
74317984 2111
8ec5d84e
AL		 2112 /* Return error only for an incorrectly formed cs-gpios property */
2113 if (nb == 0 || nb == -ENOENT)
74317984 2114 return 0;
8ec5d84e
AL		 2115 else if (nb < 0)
2116 return nb;
74317984 2117
a86854d0 2118 cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
74317984 2119 GFP_KERNEL);
8caab75f 2120 ctlr->cs_gpios = cs;
74317984 2121
8caab75f 2122 if (!ctlr->cs_gpios)
74317984
JCPV		 2123 return -ENOMEM;
2124
8caab75f 2125 for (i = 0; i < ctlr->num_chipselect; i++)
446411e1 2126 cs[i] = -ENOENT;
74317984
JCPV		 2127
2128 for (i = 0; i < nb; i++)
2129 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
2130
2131 return 0;
2132}
2133#else
8caab75f 2134static int of_spi_register_master(struct spi_controller *ctlr)
74317984
JCPV		 2135{
2136 return 0;
2137}
2138#endif
2139
bdf3a3b5
BB		 2140static int spi_controller_check_ops(struct spi_controller *ctlr)
2141{
2142 /*
b5932f5c
BB		 2143 * The controller may implement only the high-level SPI-memory like
2144 * operations if it does not support regular SPI transfers, and this is
2145 * valid use case.
2146 * If ->mem_ops is NULL, we request that at least one of the
2147 * ->transfer_xxx() method be implemented.
bdf3a3b5 2148 */
b5932f5c
BB		 2149 if (ctlr->mem_ops) {
2150 if (!ctlr->mem_ops->exec_op)
2151 return -EINVAL;
2152 } else if (!ctlr->transfer && !ctlr->transfer_one &&
2153 !ctlr->transfer_one_message) {
bdf3a3b5 2154 return -EINVAL;
b5932f5c 2155 }
bdf3a3b5
BB		 2156
2157 return 0;
2158}
2159
8ae12a0d 2160/**
8caab75f
GU		 2161 * spi_register_controller - register SPI master or slave controller
2162 * @ctlr: initialized master, originally from spi_alloc_master() or
2163 * spi_alloc_slave()
33e34dc6 2164 * Context: can sleep
8ae12a0d 2165 *
8caab75f 2166 * SPI controllers connect to their drivers using some non-SPI bus,
8ae12a0d 2167 * such as the platform bus. The final stage of probe() in that code
8caab75f 2168 * includes calling spi_register_controller() to hook up to this SPI bus glue.
8ae12a0d
DB		 2169 *
2170 * SPI controllers use board specific (often SOC specific) bus numbers,
2171 * and board-specific addressing for SPI devices combines those numbers
2172 * with chip select numbers. Since SPI does not directly support dynamic
2173 * device identification, boards need configuration tables telling which
2174 * chip is at which address.
2175 *
2176 * This must be called from context that can sleep. It returns zero on
8caab75f 2177 * success, else a negative error code (dropping the controller's refcount).
0c868461 2178 * After a successful return, the caller is responsible for calling
8caab75f 2179 * spi_unregister_controller().
97d56dc6
JMC		 2180 *
2181 * Return: zero on success, else a negative error code.
8ae12a0d 2182 */
8caab75f 2183int spi_register_controller(struct spi_controller *ctlr)
8ae12a0d 2184{
8caab75f 2185 struct device *dev = ctlr->dev.parent;
2b9603a0 2186 struct boardinfo *bi;
8ae12a0d 2187 int status = -ENODEV;
42bdd706 2188 int id, first_dynamic;
8ae12a0d 2189
0c868461
DB		 2190 if (!dev)
2191 return -ENODEV;
2192
bdf3a3b5
BB		 2193 /*
2194 * Make sure all necessary hooks are implemented before registering
2195 * the SPI controller.
2196 */
2197 status = spi_controller_check_ops(ctlr);
2198 if (status)
2199 return status;
2200
8caab75f
GU		 2201 if (!spi_controller_is_slave(ctlr)) {
2202 status = of_spi_register_master(ctlr);
6c364062
GU		 2203 if (status)
2204 return status;
2205 }
74317984 2206
082c8cb4
DB		 2207 /* even if it's just one always-selected device, there must
2208 * be at least one chipselect
2209 */
8caab75f 2210 if (ctlr->num_chipselect == 0)
082c8cb4 2211 return -EINVAL;
04b2d03a
GU		 2212 if (ctlr->bus_num >= 0) {
2213 /* devices with a fixed bus num must check-in with the num */
2214 mutex_lock(&board_lock);
2215 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2216 ctlr->bus_num + 1, GFP_KERNEL);
2217 mutex_unlock(&board_lock);
2218 if (WARN(id < 0, "couldn't get idr"))
2219 return id == -ENOSPC ? -EBUSY : id;
2220 ctlr->bus_num = id;
2221 } else if (ctlr->dev.of_node) {
2222 /* allocate dynamic bus number using Linux idr */
9b61e302
SM		 2223 id = of_alias_get_id(ctlr->dev.of_node, "spi");
2224 if (id >= 0) {
2225 ctlr->bus_num = id;
2226 mutex_lock(&board_lock);
2227 id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
2228 ctlr->bus_num + 1, GFP_KERNEL);
2229 mutex_unlock(&board_lock);
2230 if (WARN(id < 0, "couldn't get idr"))
2231 return id == -ENOSPC ? -EBUSY : id;
2232 }
2233 }
8caab75f 2234 if (ctlr->bus_num < 0) {
42bdd706
LS		 2235 first_dynamic = of_alias_get_highest_id("spi");
2236 if (first_dynamic < 0)
2237 first_dynamic = 0;
2238 else
2239 first_dynamic++;
2240
9a9a047a 2241 mutex_lock(&board_lock);
42bdd706
LS		 2242 id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
2243 0, GFP_KERNEL);
9a9a047a
SM		 2244 mutex_unlock(&board_lock);
2245 if (WARN(id < 0, "couldn't get idr"))
2246 return id;
2247 ctlr->bus_num = id;
8ae12a0d 2248 }
8caab75f
GU		 2249 INIT_LIST_HEAD(&ctlr->queue);
2250 spin_lock_init(&ctlr->queue_lock);
2251 spin_lock_init(&ctlr->bus_lock_spinlock);
2252 mutex_init(&ctlr->bus_lock_mutex);
2253 mutex_init(&ctlr->io_mutex);
2254 ctlr->bus_lock_flag = 0;
2255 init_completion(&ctlr->xfer_completion);
2256 if (!ctlr->max_dma_len)
2257 ctlr->max_dma_len = INT_MAX;
cf32b71e 2258
8ae12a0d
DB		 2259 /* register the device, then userspace will see it.
2260 * registration fails if the bus ID is in use.
2261 */
8caab75f
GU		 2262 dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
2263 status = device_add(&ctlr->dev);
9b61e302
SM		 2264 if (status < 0) {
2265 /* free bus id */
2266 mutex_lock(&board_lock);
2267 idr_remove(&spi_master_idr, ctlr->bus_num);
2268 mutex_unlock(&board_lock);
8ae12a0d 2269 goto done;
9b61e302
SM		 2270 }
2271 dev_dbg(dev, "registered %s %s\n",
8caab75f 2272 spi_controller_is_slave(ctlr) ? "slave" : "master",
9b61e302 2273 dev_name(&ctlr->dev));
8ae12a0d 2274
b5932f5c
BB		 2275 /*
2276 * If we're using a queued driver, start the queue. Note that we don't
2277 * need the queueing logic if the driver is only supporting high-level
2278 * memory operations.
2279 */
2280 if (ctlr->transfer) {
8caab75f 2281 dev_info(dev, "controller is unqueued, this is deprecated\n");
b5932f5c 2282 } else if (ctlr->transfer_one || ctlr->transfer_one_message) {
8caab75f 2283 status = spi_controller_initialize_queue(ctlr);
ffbbdd21 2284 if (status) {
8caab75f 2285 device_del(&ctlr->dev);
9b61e302
SM		 2286 /* free bus id */
2287 mutex_lock(&board_lock);
2288 idr_remove(&spi_master_idr, ctlr->bus_num);
2289 mutex_unlock(&board_lock);
ffbbdd21
LW		 2290 goto done;
2291 }
2292 }
eca2ebc7 2293 /* add statistics */
8caab75f 2294 spin_lock_init(&ctlr->statistics.lock);
ffbbdd21 2295
2b9603a0 2296 mutex_lock(&board_lock);
8caab75f 2297 list_add_tail(&ctlr->list, &spi_controller_list);
2b9603a0 2298 list_for_each_entry(bi, &board_list, list)
8caab75f 2299 spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
2b9603a0
FT		 2300 mutex_unlock(&board_lock);
2301
64bee4d2 2302 /* Register devices from the device tree and ACPI */
8caab75f
GU		 2303 of_register_spi_devices(ctlr);
2304 acpi_register_spi_devices(ctlr);
8ae12a0d
DB		 2305done:
2306 return status;
2307}
8caab75f 2308EXPORT_SYMBOL_GPL(spi_register_controller);
8ae12a0d 2309
666d5b4c
MB		 2310static void devm_spi_unregister(struct device *dev, void *res)
2311{
8caab75f 2312 spi_unregister_controller(*(struct spi_controller **)res);
666d5b4c
MB		 2313}
2314
2315/**
8caab75f
GU		 2316 * devm_spi_register_controller - register managed SPI master or slave
2317 * controller
2318 * @dev: device managing SPI controller
2319 * @ctlr: initialized controller, originally from spi_alloc_master() or
2320 * spi_alloc_slave()
666d5b4c
MB		 2321 * Context: can sleep
2322 *
8caab75f 2323 * Register a SPI device as with spi_register_controller() which will
68b892f1 2324 * automatically be unregistered and freed.
97d56dc6
JMC		 2325 *
2326 * Return: zero on success, else a negative error code.
666d5b4c 2327 */
8caab75f
GU		 2328int devm_spi_register_controller(struct device *dev,
2329 struct spi_controller *ctlr)
666d5b4c 2330{
8caab75f 2331 struct spi_controller **ptr;
666d5b4c
MB		 2332 int ret;
2333
2334 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
2335 if (!ptr)
2336 return -ENOMEM;
2337
8caab75f 2338 ret = spi_register_controller(ctlr);
4b92894e 2339 if (!ret) {
8caab75f 2340 *ptr = ctlr;
666d5b4c
MB		 2341 devres_add(dev, ptr);
2342 } else {
2343 devres_free(ptr);
2344 }
2345
2346 return ret;
2347}
8caab75f 2348EXPORT_SYMBOL_GPL(devm_spi_register_controller);
666d5b4c 2349
34860089 2350static int __unregister(struct device *dev, void *null)
8ae12a0d 2351{
34860089 2352 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 2353 return 0;
2354}
2355
2356/**
8caab75f
GU		 2357 * spi_unregister_controller - unregister SPI master or slave controller
2358 * @ctlr: the controller being unregistered
33e34dc6 2359 * Context: can sleep
8ae12a0d 2360 *
8caab75f 2361 * This call is used only by SPI controller drivers, which are the
8ae12a0d
DB		 2362 * only ones directly touching chip registers.
2363 *
2364 * This must be called from context that can sleep.
68b892f1
JH		 2365 *
2366 * Note that this function also drops a reference to the controller.
8ae12a0d 2367 */
8caab75f 2368void spi_unregister_controller(struct spi_controller *ctlr)
8ae12a0d 2369{
9b61e302 2370 struct spi_controller *found;
67f7b278 2371 int id = ctlr->bus_num;
89fc9a1a
JG		 2372 int dummy;
2373
9b61e302
SM		 2374 /* First make sure that this controller was ever added */
2375 mutex_lock(&board_lock);
67f7b278 2376 found = idr_find(&spi_master_idr, id);
9b61e302 2377 mutex_unlock(&board_lock);
8caab75f
GU		 2378 if (ctlr->queued) {
2379 if (spi_destroy_queue(ctlr))
2380 dev_err(&ctlr->dev, "queue remove failed\n");
ffbbdd21 2381 }
2b9603a0 2382 mutex_lock(&board_lock);
8caab75f 2383 list_del(&ctlr->list);
2b9603a0
FT		 2384 mutex_unlock(&board_lock);
2385
8caab75f
GU		 2386 dummy = device_for_each_child(&ctlr->dev, NULL, __unregister);
2387 device_unregister(&ctlr->dev);
9b61e302
SM		 2388 /* free bus id */
2389 mutex_lock(&board_lock);
613bd1ea
JN		 2390 if (found == ctlr)
2391 idr_remove(&spi_master_idr, id);
9b61e302 2392 mutex_unlock(&board_lock);
8ae12a0d 2393}
8caab75f 2394EXPORT_SYMBOL_GPL(spi_unregister_controller);
8ae12a0d 2395
8caab75f 2396int spi_controller_suspend(struct spi_controller *ctlr)
ffbbdd21
LW		 2397{
2398 int ret;
2399
8caab75f
GU		 2400 /* Basically no-ops for non-queued controllers */
2401 if (!ctlr->queued)
ffbbdd21
LW		 2402 return 0;
2403
8caab75f 2404 ret = spi_stop_queue(ctlr);
ffbbdd21 2405 if (ret)
8caab75f 2406 dev_err(&ctlr->dev, "queue stop failed\n");
ffbbdd21
LW		 2407
2408 return ret;
2409}
8caab75f 2410EXPORT_SYMBOL_GPL(spi_controller_suspend);
ffbbdd21 2411
8caab75f 2412int spi_controller_resume(struct spi_controller *ctlr)
ffbbdd21
LW		 2413{
2414 int ret;
2415
8caab75f 2416 if (!ctlr->queued)
ffbbdd21
LW		 2417 return 0;
2418
8caab75f 2419 ret = spi_start_queue(ctlr);
ffbbdd21 2420 if (ret)
8caab75f 2421 dev_err(&ctlr->dev, "queue restart failed\n");
ffbbdd21
LW		 2422
2423 return ret;
2424}
8caab75f 2425EXPORT_SYMBOL_GPL(spi_controller_resume);
ffbbdd21 2426
8caab75f 2427static int __spi_controller_match(struct device *dev, const void *data)
5ed2c832 2428{
8caab75f 2429 struct spi_controller *ctlr;
9f3b795a 2430 const u16 *bus_num = data;
5ed2c832 2431
8caab75f
GU		 2432 ctlr = container_of(dev, struct spi_controller, dev);
2433 return ctlr->bus_num == *bus_num;
5ed2c832
DY		 2434}
2435
8ae12a0d
DB		 2436/**
2437 * spi_busnum_to_master - look up master associated with bus_num
2438 * @bus_num: the master's bus number
33e34dc6 2439 * Context: can sleep
8ae12a0d
DB		 2440 *
2441 * This call may be used with devices that are registered after
2442 * arch init time. It returns a refcounted pointer to the relevant
8caab75f 2443 * spi_controller (which the caller must release), or NULL if there is
8ae12a0d 2444 * no such master registered.
97d56dc6
JMC		 2445 *
2446 * Return: the SPI master structure on success, else NULL.
8ae12a0d 2447 */
8caab75f 2448struct spi_controller *spi_busnum_to_master(u16 bus_num)
8ae12a0d 2449{
49dce689 2450 struct device *dev;
8caab75f 2451 struct spi_controller *ctlr = NULL;
5ed2c832 2452
695794ae 2453 dev = class_find_device(&spi_master_class, NULL, &bus_num,
8caab75f 2454 __spi_controller_match);
5ed2c832 2455 if (dev)
8caab75f 2456 ctlr = container_of(dev, struct spi_controller, dev);
5ed2c832 2457 /* reference got in class_find_device */
8caab75f 2458 return ctlr;
8ae12a0d
DB		 2459}
2460EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2461
d780c371
MS		 2462/*-------------------------------------------------------------------------*/
2463
2464/* Core methods for SPI resource management */
2465
2466/**
2467 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2468 * during the processing of a spi_message while using
2469 * spi_transfer_one
2470 * @spi: the spi device for which we allocate memory
2471 * @release: the release code to execute for this resource
2472 * @size: size to alloc and return
2473 * @gfp: GFP allocation flags
2474 *
2475 * Return: the pointer to the allocated data
2476 *
2477 * This may get enhanced in the future to allocate from a memory pool
8caab75f 2478 * of the @spi_device or @spi_controller to avoid repeated allocations.
d780c371
MS		 2479 */
2480void *spi_res_alloc(struct spi_device *spi,
2481 spi_res_release_t release,
2482 size_t size, gfp_t gfp)
2483{
2484 struct spi_res *sres;
2485
2486 sres = kzalloc(sizeof(*sres) + size, gfp);
2487 if (!sres)
2488 return NULL;
2489
2490 INIT_LIST_HEAD(&sres->entry);
2491 sres->release = release;
2492
2493 return sres->data;
2494}
2495EXPORT_SYMBOL_GPL(spi_res_alloc);
2496
2497/**
2498 * spi_res_free - free an spi resource
2499 * @res: pointer to the custom data of a resource
2500 *
2501 */
2502void spi_res_free(void *res)
2503{
2504 struct spi_res *sres = container_of(res, struct spi_res, data);
2505
2506 if (!res)
2507 return;
2508
2509 WARN_ON(!list_empty(&sres->entry));
2510 kfree(sres);
2511}
2512EXPORT_SYMBOL_GPL(spi_res_free);
2513
2514/**
2515 * spi_res_add - add a spi_res to the spi_message
2516 * @message: the spi message
2517 * @res: the spi_resource
2518 */
2519void spi_res_add(struct spi_message *message, void *res)
2520{
2521 struct spi_res *sres = container_of(res, struct spi_res, data);
2522
2523 WARN_ON(!list_empty(&sres->entry));
2524 list_add_tail(&sres->entry, &message->resources);
2525}
2526EXPORT_SYMBOL_GPL(spi_res_add);
2527
2528/**
2529 * spi_res_release - release all spi resources for this message
8caab75f 2530 * @ctlr: the @spi_controller
d780c371
MS		 2531 * @message: the @spi_message
2532 */
8caab75f 2533void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
d780c371
MS		 2534{
2535 struct spi_res *res;
2536
2537 while (!list_empty(&message->resources)) {
2538 res = list_last_entry(&message->resources,
2539 struct spi_res, entry);
2540
2541 if (res->release)
8caab75f 2542 res->release(ctlr, message, res->data);
d780c371
MS		 2543
2544 list_del(&res->entry);
2545
2546 kfree(res);
2547 }
2548}
2549EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2550
2551/*-------------------------------------------------------------------------*/
2552
523baf5a
MS		 2553/* Core methods for spi_message alterations */
2554
8caab75f 2555static void __spi_replace_transfers_release(struct spi_controller *ctlr,
523baf5a
MS		 2556 struct spi_message *msg,
2557 void *res)
2558{
2559 struct spi_replaced_transfers *rxfer = res;
2560 size_t i;
2561
2562 /* call extra callback if requested */
2563 if (rxfer->release)
8caab75f 2564 rxfer->release(ctlr, msg, res);
523baf5a
MS		 2565
2566 /* insert replaced transfers back into the message */
2567 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2568
2569 /* remove the formerly inserted entries */
2570 for (i = 0; i < rxfer->inserted; i++)
2571 list_del(&rxfer->inserted_transfers[i].transfer_list);
2572}
2573
2574/**
2575 * spi_replace_transfers - replace transfers with several transfers
2576 * and register change with spi_message.resources
2577 * @msg: the spi_message we work upon
2578 * @xfer_first: the first spi_transfer we want to replace
2579 * @remove: number of transfers to remove
2580 * @insert: the number of transfers we want to insert instead
2581 * @release: extra release code necessary in some circumstances
2582 * @extradatasize: extra data to allocate (with alignment guarantees
2583 * of struct @spi_transfer)
05885397 2584 * @gfp: gfp flags
523baf5a
MS		 2585 *
2586 * Returns: pointer to @spi_replaced_transfers,
2587 * PTR_ERR(...) in case of errors.
2588 */
2589struct spi_replaced_transfers *spi_replace_transfers(
2590 struct spi_message *msg,
2591 struct spi_transfer *xfer_first,
2592 size_t remove,
2593 size_t insert,
2594 spi_replaced_release_t release,
2595 size_t extradatasize,
2596 gfp_t gfp)
2597{
2598 struct spi_replaced_transfers *rxfer;
2599 struct spi_transfer *xfer;
2600 size_t i;
2601
2602 /* allocate the structure using spi_res */
2603 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2604 insert * sizeof(struct spi_transfer)
2605 + sizeof(struct spi_replaced_transfers)
2606 + extradatasize,
2607 gfp);
2608 if (!rxfer)
2609 return ERR_PTR(-ENOMEM);
2610
2611 /* the release code to invoke before running the generic release */
2612 rxfer->release = release;
2613
2614 /* assign extradata */
2615 if (extradatasize)
2616 rxfer->extradata =
2617 &rxfer->inserted_transfers[insert];
2618
2619 /* init the replaced_transfers list */
2620 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2621
2622 /* assign the list_entry after which we should reinsert
2623 * the @replaced_transfers - it may be spi_message.messages!
2624 */
2625 rxfer->replaced_after = xfer_first->transfer_list.prev;
2626
2627 /* remove the requested number of transfers */
2628 for (i = 0; i < remove; i++) {
2629 /* if the entry after replaced_after it is msg->transfers
2630 * then we have been requested to remove more transfers
2631 * than are in the list
2632 */
2633 if (rxfer->replaced_after->next == &msg->transfers) {
2634 dev_err(&msg->spi->dev,
2635 "requested to remove more spi_transfers than are available\n");
2636 /* insert replaced transfers back into the message */
2637 list_splice(&rxfer->replaced_transfers,
2638 rxfer->replaced_after);
2639
2640 /* free the spi_replace_transfer structure */
2641 spi_res_free(rxfer);
2642
2643 /* and return with an error */
2644 return ERR_PTR(-EINVAL);
2645 }
2646
2647 /* remove the entry after replaced_after from list of
2648 * transfers and add it to list of replaced_transfers
2649 */
2650 list_move_tail(rxfer->replaced_after->next,
2651 &rxfer->replaced_transfers);
2652 }
2653
2654 /* create copy of the given xfer with identical settings
2655 * based on the first transfer to get removed
2656 */
2657 for (i = 0; i < insert; i++) {
2658 /* we need to run in reverse order */
2659 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2660
2661 /* copy all spi_transfer data */
2662 memcpy(xfer, xfer_first, sizeof(*xfer));
2663
2664 /* add to list */
2665 list_add(&xfer->transfer_list, rxfer->replaced_after);
2666
2667 /* clear cs_change and delay_usecs for all but the last */
2668 if (i) {
2669 xfer->cs_change = false;
2670 xfer->delay_usecs = 0;
2671 }
2672 }
2673
2674 /* set up inserted */
2675 rxfer->inserted = insert;
2676
2677 /* and register it with spi_res/spi_message */
2678 spi_res_add(msg, rxfer);
2679
2680 return rxfer;
2681}
2682EXPORT_SYMBOL_GPL(spi_replace_transfers);
2683
8caab75f 2684static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
08933418
FE		 2685 struct spi_message *msg,
2686 struct spi_transfer **xferp,
2687 size_t maxsize,
2688 gfp_t gfp)
d9f12122
MS		 2689{
2690 struct spi_transfer *xfer = *xferp, *xfers;
2691 struct spi_replaced_transfers *srt;
2692 size_t offset;
2693 size_t count, i;
2694
2695 /* warn once about this fact that we are splitting a transfer */
2696 dev_warn_once(&msg->spi->dev,
7d62f51e 2697 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
d9f12122
MS		 2698 xfer->len, maxsize);
2699
2700 /* calculate how many we have to replace */
2701 count = DIV_ROUND_UP(xfer->len, maxsize);
2702
2703 /* create replacement */
2704 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2705 if (IS_ERR(srt))
2706 return PTR_ERR(srt);
d9f12122
MS		 2707 xfers = srt->inserted_transfers;
2708
2709 /* now handle each of those newly inserted spi_transfers
2710 * note that the replacements spi_transfers all are preset
2711 * to the same values as *xferp, so tx_buf, rx_buf and len
2712 * are all identical (as well as most others)
2713 * so we just have to fix up len and the pointers.
2714 *
2715 * this also includes support for the depreciated
2716 * spi_message.is_dma_mapped interface
2717 */
2718
2719 /* the first transfer just needs the length modified, so we
2720 * run it outside the loop
2721 */
c8dab77a 2722 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
d9f12122
MS		 2723
2724 /* all the others need rx_buf/tx_buf also set */
2725 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2726 /* update rx_buf, tx_buf and dma */
2727 if (xfers[i].rx_buf)
2728 xfers[i].rx_buf += offset;
2729 if (xfers[i].rx_dma)
2730 xfers[i].rx_dma += offset;
2731 if (xfers[i].tx_buf)
2732 xfers[i].tx_buf += offset;
2733 if (xfers[i].tx_dma)
2734 xfers[i].tx_dma += offset;
2735
2736 /* update length */
2737 xfers[i].len = min(maxsize, xfers[i].len - offset);
2738 }
2739
2740 /* we set up xferp to the last entry we have inserted,
2741 * so that we skip those already split transfers
2742 */
2743 *xferp = &xfers[count - 1];
2744
2745 /* increment statistics counters */
8caab75f 2746 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
d9f12122
MS		 2747 transfers_split_maxsize);
2748 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2749 transfers_split_maxsize);
2750
2751 return 0;
2752}
2753
2754/**
2755 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2756 * when an individual transfer exceeds a
2757 * certain size
8caab75f 2758 * @ctlr: the @spi_controller for this transfer
3700ce95
MI		 2759 * @msg: the @spi_message to transform
2760 * @maxsize: the maximum when to apply this
10f11a22 2761 * @gfp: GFP allocation flags
d9f12122
MS		 2762 *
2763 * Return: status of transformation
2764 */
8caab75f 2765int spi_split_transfers_maxsize(struct spi_controller *ctlr,
d9f12122
MS		 2766 struct spi_message *msg,
2767 size_t maxsize,
2768 gfp_t gfp)
2769{
2770 struct spi_transfer *xfer;
2771 int ret;
2772
2773 /* iterate over the transfer_list,
2774 * but note that xfer is advanced to the last transfer inserted
2775 * to avoid checking sizes again unnecessarily (also xfer does
2776 * potentiall belong to a different list by the time the
2777 * replacement has happened
2778 */
2779 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2780 if (xfer->len > maxsize) {
8caab75f
GU		 2781 ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
2782 maxsize, gfp);
d9f12122
MS		 2783 if (ret)
2784 return ret;
2785 }
2786 }
2787
2788 return 0;
2789}
2790EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
8ae12a0d
DB		 2791
2792/*-------------------------------------------------------------------------*/
2793
8caab75f 2794/* Core methods for SPI controller protocol drivers. Some of the
7d077197
DB		 2795 * other core methods are currently defined as inline functions.
2796 */
2797
8caab75f
GU		 2798static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
2799 u8 bits_per_word)
63ab645f 2800{
8caab75f 2801 if (ctlr->bits_per_word_mask) {
63ab645f
SB		 2802 /* Only 32 bits fit in the mask */
2803 if (bits_per_word > 32)
2804 return -EINVAL;
8caab75f 2805 if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
63ab645f
SB		 2806 return -EINVAL;
2807 }
2808
2809 return 0;
2810}
2811
7d077197
DB		 2812/**
2813 * spi_setup - setup SPI mode and clock rate
2814 * @spi: the device whose settings are being modified
2815 * Context: can sleep, and no requests are queued to the device
2816 *
2817 * SPI protocol drivers may need to update the transfer mode if the
2818 * device doesn't work with its default. They may likewise need
2819 * to update clock rates or word sizes from initial values. This function
2820 * changes those settings, and must be called from a context that can sleep.
2821 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2822 * effect the next time the device is selected and data is transferred to
2823 * or from it. When this function returns, the spi device is deselected.
2824 *
2825 * Note that this call will fail if the protocol driver specifies an option
2826 * that the underlying controller or its driver does not support. For
2827 * example, not all hardware supports wire transfers using nine bit words,
2828 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2829 *
2830 * Return: zero on success, else a negative error code.
7d077197
DB		 2831 */
2832int spi_setup(struct spi_device *spi)
2833{
83596fbe 2834 unsigned bad_bits, ugly_bits;
5ab8d262 2835 int status;
7d077197 2836
f477b7fb 2837 /* check mode to prevent that DUAL and QUAD set at the same time
2838 */
2839 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2840 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2841 dev_err(&spi->dev,
2842 "setup: can not select dual and quad at the same time\n");
2843 return -EINVAL;
2844 }
2845 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2846 */
2847 if ((spi->mode & SPI_3WIRE) && (spi->mode &
6b03061f
YNG		 2848 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
2849 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
f477b7fb 2850 return -EINVAL;
e7db06b5 2851 /* help drivers fail *cleanly* when they need options
8caab75f 2852 * that aren't supported with their current controller
cbaa62e0
DL		 2853 * SPI_CS_WORD has a fallback software implementation,
2854 * so it is ignored here.
e7db06b5 2855 */
cbaa62e0 2856 bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
83596fbe 2857 ugly_bits = bad_bits &
6b03061f
YNG		 2858 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
2859 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
83596fbe
GU		 2860 if (ugly_bits) {
2861 dev_warn(&spi->dev,
2862 "setup: ignoring unsupported mode bits %x\n",
2863 ugly_bits);
2864 spi->mode &= ~ugly_bits;
2865 bad_bits &= ~ugly_bits;
2866 }
e7db06b5 2867 if (bad_bits) {
eb288a1f 2868 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2869 bad_bits);
2870 return -EINVAL;
2871 }
2872
7d077197
DB		 2873 if (!spi->bits_per_word)
2874 spi->bits_per_word = 8;
2875
8caab75f
GU		 2876 status = __spi_validate_bits_per_word(spi->controller,
2877 spi->bits_per_word);
5ab8d262
AS		 2878 if (status)
2879 return status;
63ab645f 2880
052eb2d4 2881 if (!spi->max_speed_hz)
8caab75f 2882 spi->max_speed_hz = spi->controller->max_speed_hz;
052eb2d4 2883
8caab75f
GU		 2884 if (spi->controller->setup)
2885 status = spi->controller->setup(spi);
7d077197 2886
abeedb01
FCJ		 2887 spi_set_cs(spi, false);
2888
5fe5f05e 2889 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2890 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2891 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2892 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2893 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2894 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2895 spi->bits_per_word, spi->max_speed_hz,
2896 status);
2897
2898 return status;
2899}
2900EXPORT_SYMBOL_GPL(spi_setup);
2901
90808738 2902static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e 2903{
8caab75f 2904 struct spi_controller *ctlr = spi->controller;
e6811d1d 2905 struct spi_transfer *xfer;
6ea31293 2906 int w_size;
cf32b71e 2907
24a0013a
MB		 2908 if (list_empty(&message->transfers))
2909 return -EINVAL;
24a0013a 2910
cbaa62e0 2911 /* If an SPI controller does not support toggling the CS line on each
71388b21
DL		 2912 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
2913 * for the CS line, we can emulate the CS-per-word hardware function by
cbaa62e0
DL		 2914 * splitting transfers into one-word transfers and ensuring that
2915 * cs_change is set for each transfer.
2916 */
71388b21
DL		 2917 if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
2918 gpio_is_valid(spi->cs_gpio))) {
cbaa62e0
DL		 2919 size_t maxsize;
2920 int ret;
2921
2922 maxsize = (spi->bits_per_word + 7) / 8;
2923
2924 /* spi_split_transfers_maxsize() requires message->spi */
2925 message->spi = spi;
2926
2927 ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
2928 GFP_KERNEL);
2929 if (ret)
2930 return ret;
2931
2932 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2933 /* don't change cs_change on the last entry in the list */
2934 if (list_is_last(&xfer->transfer_list, &message->transfers))
2935 break;
2936 xfer->cs_change = 1;
2937 }
2938 }
2939
cf32b71e
ES		 2940 /* Half-duplex links include original MicroWire, and ones with
2941 * only one data pin like SPI_3WIRE (switches direction) or where
2942 * either MOSI or MISO is missing. They can also be caused by
2943 * software limitations.
2944 */
8caab75f
GU		 2945 if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
2946 (spi->mode & SPI_3WIRE)) {
2947 unsigned flags = ctlr->flags;
cf32b71e
ES		 2948
2949 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2950 if (xfer->rx_buf && xfer->tx_buf)
2951 return -EINVAL;
8caab75f 2952 if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
cf32b71e 2953 return -EINVAL;
8caab75f 2954 if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
cf32b71e
ES		 2955 return -EINVAL;
2956 }
2957 }
2958
e6811d1d 2959 /**
059b8ffe
LD		 2960 * Set transfer bits_per_word and max speed as spi device default if
2961 * it is not set for this transfer.
f477b7fb 2962 * Set transfer tx_nbits and rx_nbits as single transfer default
2963 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2964 */
77e80588 2965 message->frame_length = 0;
e6811d1d 2966 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2967 message->frame_length += xfer->len;
e6811d1d
LD		 2968 if (!xfer->bits_per_word)
2969 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2970
2971 if (!xfer->speed_hz)
059b8ffe 2972 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3 2973 if (!xfer->speed_hz)
8caab75f 2974 xfer->speed_hz = ctlr->max_speed_hz;
a6f87fad 2975
8caab75f
GU		 2976 if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
2977 xfer->speed_hz = ctlr->max_speed_hz;
56ede94a 2978
8caab75f 2979 if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
63ab645f 2980 return -EINVAL;
a2fd4f9f 2981
4d94bd21
II		 2982 /*
2983 * SPI transfer length should be multiple of SPI word size
2984 * where SPI word size should be power-of-two multiple
2985 */
2986 if (xfer->bits_per_word <= 8)
2987 w_size = 1;
2988 else if (xfer->bits_per_word <= 16)
2989 w_size = 2;
2990 else
2991 w_size = 4;
2992
4d94bd21 2993 /* No partial transfers accepted */
6ea31293 2994 if (xfer->len % w_size)
4d94bd21
II		 2995 return -EINVAL;
2996
8caab75f
GU		 2997 if (xfer->speed_hz && ctlr->min_speed_hz &&
2998 xfer->speed_hz < ctlr->min_speed_hz)
a2fd4f9f 2999 return -EINVAL;
f477b7fb 3000
3001 if (xfer->tx_buf && !xfer->tx_nbits)
3002 xfer->tx_nbits = SPI_NBITS_SINGLE;
3003 if (xfer->rx_buf && !xfer->rx_nbits)
3004 xfer->rx_nbits = SPI_NBITS_SINGLE;
3005 /* check transfer tx/rx_nbits:
1afd9989
GU		 3006 * 1. check the value matches one of single, dual and quad
3007 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 3008 */
db90a441
SP		 3009 if (xfer->tx_buf) {
3010 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
3011 xfer->tx_nbits != SPI_NBITS_DUAL &&
3012 xfer->tx_nbits != SPI_NBITS_QUAD)
3013 return -EINVAL;
3014 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
3015 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
3016 return -EINVAL;
3017 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
3018 !(spi->mode & SPI_TX_QUAD))
3019 return -EINVAL;
db90a441 3020 }
f477b7fb 3021 /* check transfer rx_nbits */
db90a441
SP		 3022 if (xfer->rx_buf) {
3023 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
3024 xfer->rx_nbits != SPI_NBITS_DUAL &&
3025 xfer->rx_nbits != SPI_NBITS_QUAD)
3026 return -EINVAL;
3027 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
3028 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
3029 return -EINVAL;
3030 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
3031 !(spi->mode & SPI_RX_QUAD))
3032 return -EINVAL;
db90a441 3033 }
e6811d1d
LD		 3034 }
3035
cf32b71e 3036 message->status = -EINPROGRESS;
90808738
MB		 3037
3038 return 0;
3039}
3040
3041static int __spi_async(struct spi_device *spi, struct spi_message *message)
3042{
8caab75f 3043 struct spi_controller *ctlr = spi->controller;
90808738 3044
b5932f5c
BB		 3045 /*
3046 * Some controllers do not support doing regular SPI transfers. Return
3047 * ENOTSUPP when this is the case.
3048 */
3049 if (!ctlr->transfer)
3050 return -ENOTSUPP;
3051
90808738
MB		 3052 message->spi = spi;
3053
8caab75f 3054 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
eca2ebc7
MS		 3055 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
3056
90808738
MB		 3057 trace_spi_message_submit(message);
3058
8caab75f 3059 return ctlr->transfer(spi, message);
cf32b71e
ES		 3060}
3061
568d0697
DB		 3062/**
3063 * spi_async - asynchronous SPI transfer
3064 * @spi: device with which data will be exchanged
3065 * @message: describes the data transfers, including completion callback
3066 * Context: any (irqs may be blocked, etc)
3067 *
3068 * This call may be used in_irq and other contexts which can't sleep,
3069 * as well as from task contexts which can sleep.
3070 *
3071 * The completion callback is invoked in a context which can't sleep.
3072 * Before that invocation, the value of message->status is undefined.
3073 * When the callback is issued, message->status holds either zero (to
3074 * indicate complete success) or a negative error code. After that
3075 * callback returns, the driver which issued the transfer request may
3076 * deallocate the associated memory; it's no longer in use by any SPI
3077 * core or controller driver code.
3078 *
3079 * Note that although all messages to a spi_device are handled in
3080 * FIFO order, messages may go to different devices in other orders.
3081 * Some device might be higher priority, or have various "hard" access
3082 * time requirements, for example.
3083 *
3084 * On detection of any fault during the transfer, processing of
3085 * the entire message is aborted, and the device is deselected.
3086 * Until returning from the associated message completion callback,
3087 * no other spi_message queued to that device will be processed.
3088 * (This rule applies equally to all the synchronous transfer calls,
3089 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 3090 *
3091 * Return: zero on success, else a negative error code.
568d0697
DB		 3092 */
3093int spi_async(struct spi_device *spi, struct spi_message *message)
3094{
8caab75f 3095 struct spi_controller *ctlr = spi->controller;
cf32b71e
ES		 3096 int ret;
3097 unsigned long flags;
568d0697 3098
90808738
MB		 3099 ret = __spi_validate(spi, message);
3100 if (ret != 0)
3101 return ret;
3102
8caab75f 3103 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
568d0697 3104
8caab75f 3105 if (ctlr->bus_lock_flag)
cf32b71e
ES		 3106 ret = -EBUSY;
3107 else
3108 ret = __spi_async(spi, message);
568d0697 3109
8caab75f 3110 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
cf32b71e
ES		 3111
3112 return ret;
568d0697
DB		 3113}
3114EXPORT_SYMBOL_GPL(spi_async);
3115
cf32b71e
ES		 3116/**
3117 * spi_async_locked - version of spi_async with exclusive bus usage
3118 * @spi: device with which data will be exchanged
3119 * @message: describes the data transfers, including completion callback
3120 * Context: any (irqs may be blocked, etc)
3121 *
3122 * This call may be used in_irq and other contexts which can't sleep,
3123 * as well as from task contexts which can sleep.
3124 *
3125 * The completion callback is invoked in a context which can't sleep.
3126 * Before that invocation, the value of message->status is undefined.
3127 * When the callback is issued, message->status holds either zero (to
3128 * indicate complete success) or a negative error code. After that
3129 * callback returns, the driver which issued the transfer request may
3130 * deallocate the associated memory; it's no longer in use by any SPI
3131 * core or controller driver code.
3132 *
3133 * Note that although all messages to a spi_device are handled in
3134 * FIFO order, messages may go to different devices in other orders.
3135 * Some device might be higher priority, or have various "hard" access
3136 * time requirements, for example.
3137 *
3138 * On detection of any fault during the transfer, processing of
3139 * the entire message is aborted, and the device is deselected.
3140 * Until returning from the associated message completion callback,
3141 * no other spi_message queued to that device will be processed.
3142 * (This rule applies equally to all the synchronous transfer calls,
3143 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 3144 *
3145 * Return: zero on success, else a negative error code.
cf32b71e
ES		 3146 */
3147int spi_async_locked(struct spi_device *spi, struct spi_message *message)
3148{
8caab75f 3149 struct spi_controller *ctlr = spi->controller;
cf32b71e
ES		 3150 int ret;
3151 unsigned long flags;
3152
90808738
MB		 3153 ret = __spi_validate(spi, message);
3154 if (ret != 0)
3155 return ret;
3156
8caab75f 3157 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
cf32b71e
ES		 3158
3159 ret = __spi_async(spi, message);
3160
8caab75f 3161 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
cf32b71e
ES		 3162
3163 return ret;
3164
3165}
3166EXPORT_SYMBOL_GPL(spi_async_locked);
3167
7d077197
DB		 3168/*-------------------------------------------------------------------------*/
3169
8caab75f 3170/* Utility methods for SPI protocol drivers, layered on
7d077197
DB		 3171 * top of the core. Some other utility methods are defined as
3172 * inline functions.
3173 */
3174
5d870c8e
AM		 3175static void spi_complete(void *arg)
3176{
3177 complete(arg);
3178}
3179
ef4d96ec 3180static int __spi_sync(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 3181{
3182 DECLARE_COMPLETION_ONSTACK(done);
3183 int status;
8caab75f 3184 struct spi_controller *ctlr = spi->controller;
0461a414
MB		 3185 unsigned long flags;
3186
3187 status = __spi_validate(spi, message);
3188 if (status != 0)
3189 return status;
cf32b71e
ES		 3190
3191 message->complete = spi_complete;
3192 message->context = &done;
0461a414 3193 message->spi = spi;
cf32b71e 3194
8caab75f 3195 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
eca2ebc7
MS		 3196 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
3197
0461a414
MB		 3198 /* If we're not using the legacy transfer method then we will
3199 * try to transfer in the calling context so special case.
3200 * This code would be less tricky if we could remove the
3201 * support for driver implemented message queues.
3202 */
8caab75f
GU		 3203 if (ctlr->transfer == spi_queued_transfer) {
3204 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
0461a414
MB		 3205
3206 trace_spi_message_submit(message);
3207
3208 status = __spi_queued_transfer(spi, message, false);
3209
8caab75f 3210 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
0461a414
MB		 3211 } else {
3212 status = spi_async_locked(spi, message);
3213 }
cf32b71e 3214
cf32b71e 3215 if (status == 0) {
0461a414
MB		 3216 /* Push out the messages in the calling context if we
3217 * can.
3218 */
8caab75f
GU		 3219 if (ctlr->transfer == spi_queued_transfer) {
3220 SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
eca2ebc7
MS		 3221 spi_sync_immediate);
3222 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
3223 spi_sync_immediate);
8caab75f 3224 __spi_pump_messages(ctlr, false);
eca2ebc7 3225 }
0461a414 3226
cf32b71e
ES		 3227 wait_for_completion(&done);
3228 status = message->status;
3229 }
3230 message->context = NULL;
3231 return status;
3232}
3233
8ae12a0d
DB		 3234/**
3235 * spi_sync - blocking/synchronous SPI data transfers
3236 * @spi: device with which data will be exchanged
3237 * @message: describes the data transfers
33e34dc6 3238 * Context: can sleep
8ae12a0d
DB		 3239 *
3240 * This call may only be used from a context that may sleep. The sleep
3241 * is non-interruptible, and has no timeout. Low-overhead controller
3242 * drivers may DMA directly into and out of the message buffers.
3243 *
3244 * Note that the SPI device's chip select is active during the message,
3245 * and then is normally disabled between messages. Drivers for some
3246 * frequently-used devices may want to minimize costs of selecting a chip,
3247 * by leaving it selected in anticipation that the next message will go
3248 * to the same chip. (That may increase power usage.)
3249 *
0c868461
DB		 3250 * Also, the caller is guaranteeing that the memory associated with the
3251 * message will not be freed before this call returns.
3252 *
97d56dc6 3253 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 3254 */
3255int spi_sync(struct spi_device *spi, struct spi_message *message)
3256{
ef4d96ec
MB		 3257 int ret;
3258
8caab75f 3259 mutex_lock(&spi->controller->bus_lock_mutex);
ef4d96ec 3260 ret = __spi_sync(spi, message);
8caab75f 3261 mutex_unlock(&spi->controller->bus_lock_mutex);
ef4d96ec
MB		 3262
3263 return ret;
8ae12a0d
DB		 3264}
3265EXPORT_SYMBOL_GPL(spi_sync);
3266
cf32b71e
ES		 3267/**
3268 * spi_sync_locked - version of spi_sync with exclusive bus usage
3269 * @spi: device with which data will be exchanged
3270 * @message: describes the data transfers
3271 * Context: can sleep
3272 *
3273 * This call may only be used from a context that may sleep. The sleep
3274 * is non-interruptible, and has no timeout. Low-overhead controller
3275 * drivers may DMA directly into and out of the message buffers.
3276 *
3277 * This call should be used by drivers that require exclusive access to the
25985edc 3278 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 3279 * be released by a spi_bus_unlock call when the exclusive access is over.
3280 *
97d56dc6 3281 * Return: zero on success, else a negative error code.
cf32b71e
ES		 3282 */
3283int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
3284{
ef4d96ec 3285 return __spi_sync(spi, message);
cf32b71e
ES		 3286}
3287EXPORT_SYMBOL_GPL(spi_sync_locked);
3288
3289/**
3290 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
8caab75f 3291 * @ctlr: SPI bus master that should be locked for exclusive bus access
cf32b71e
ES		 3292 * Context: can sleep
3293 *
3294 * This call may only be used from a context that may sleep. The sleep
3295 * is non-interruptible, and has no timeout.
3296 *
3297 * This call should be used by drivers that require exclusive access to the
3298 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
3299 * exclusive access is over. Data transfer must be done by spi_sync_locked
3300 * and spi_async_locked calls when the SPI bus lock is held.
3301 *
97d56dc6 3302 * Return: always zero.
cf32b71e 3303 */
8caab75f 3304int spi_bus_lock(struct spi_controller *ctlr)
cf32b71e
ES		 3305{
3306 unsigned long flags;
3307
8caab75f 3308 mutex_lock(&ctlr->bus_lock_mutex);
cf32b71e 3309
8caab75f
GU		 3310 spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
3311 ctlr->bus_lock_flag = 1;
3312 spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
cf32b71e
ES		 3313
3314 /* mutex remains locked until spi_bus_unlock is called */
3315
3316 return 0;
3317}
3318EXPORT_SYMBOL_GPL(spi_bus_lock);
3319
3320/**
3321 * spi_bus_unlock - release the lock for exclusive SPI bus usage
8caab75f 3322 * @ctlr: SPI bus master that was locked for exclusive bus access
cf32b71e
ES		 3323 * Context: can sleep
3324 *
3325 * This call may only be used from a context that may sleep. The sleep
3326 * is non-interruptible, and has no timeout.
3327 *
3328 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
3329 * call.
3330 *
97d56dc6 3331 * Return: always zero.
cf32b71e 3332 */
8caab75f 3333int spi_bus_unlock(struct spi_controller *ctlr)
cf32b71e 3334{
8caab75f 3335 ctlr->bus_lock_flag = 0;
cf32b71e 3336
8caab75f 3337 mutex_unlock(&ctlr->bus_lock_mutex);
cf32b71e
ES		 3338
3339 return 0;
3340}
3341EXPORT_SYMBOL_GPL(spi_bus_unlock);
3342
a9948b61 3343/* portable code must never pass more than 32 bytes */
5fe5f05e 3344#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 3345
3346static u8 *buf;
3347
3348/**
3349 * spi_write_then_read - SPI synchronous write followed by read
3350 * @spi: device with which data will be exchanged
3351 * @txbuf: data to be written (need not be dma-safe)
3352 * @n_tx: size of txbuf, in bytes
27570497
JP		 3353 * @rxbuf: buffer into which data will be read (need not be dma-safe)
3354 * @n_rx: size of rxbuf, in bytes
33e34dc6 3355 * Context: can sleep
8ae12a0d
DB		 3356 *
3357 * This performs a half duplex MicroWire style transaction with the
3358 * device, sending txbuf and then reading rxbuf. The return value
3359 * is zero for success, else a negative errno status code.
b885244e 3360 * This call may only be used from a context that may sleep.
8ae12a0d 3361 *
0c868461 3362 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 3363 * portable code should never use this for more than 32 bytes.
3364 * Performance-sensitive or bulk transfer code should instead use
0c868461 3365 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 3366 *
3367 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 3368 */
3369int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 3370 const void *txbuf, unsigned n_tx,
3371 void *rxbuf, unsigned n_rx)
8ae12a0d 3372{
068f4070 3373 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 3374
3375 int status;
3376 struct spi_message message;
bdff549e 3377 struct spi_transfer x[2];
8ae12a0d
DB		 3378 u8 *local_buf;
3379
b3a223ee
MB		 3380 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3381 * copying here, (as a pure convenience thing), but we can
3382 * keep heap costs out of the hot path unless someone else is
3383 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 3384 */
b3a223ee 3385 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 3386 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3387 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 3388 if (!local_buf)
3389 return -ENOMEM;
3390 } else {
3391 local_buf = buf;
3392 }
8ae12a0d 3393
8275c642 3394 spi_message_init(&message);
5fe5f05e 3395 memset(x, 0, sizeof(x));
bdff549e
DB		 3396 if (n_tx) {
3397 x[0].len = n_tx;
3398 spi_message_add_tail(&x[0], &message);
3399 }
3400 if (n_rx) {
3401 x[1].len = n_rx;
3402 spi_message_add_tail(&x[1], &message);
3403 }
8275c642 3404
8ae12a0d 3405 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 3406 x[0].tx_buf = local_buf;
3407 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 3408
3409 /* do the i/o */
8ae12a0d 3410 status = spi_sync(spi, &message);
9b938b74 3411 if (status == 0)
bdff549e 3412 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 3413
bdff549e 3414 if (x[0].tx_buf == buf)
068f4070 3415 mutex_unlock(&lock);
8ae12a0d
DB		 3416 else
3417 kfree(local_buf);
3418
3419 return status;
3420}
3421EXPORT_SYMBOL_GPL(spi_write_then_read);
3422
3423/*-------------------------------------------------------------------------*/
3424
5f143af7 3425#if IS_ENABLED(CONFIG_OF)
ce79d54a
PA		 3426static int __spi_of_device_match(struct device *dev, void *data)
3427{
3428 return dev->of_node == data;
3429}
3430
3431/* must call put_device() when done with returned spi_device device */
5f143af7 3432struct spi_device *of_find_spi_device_by_node(struct device_node *node)
ce79d54a
PA		 3433{
3434 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3435 __spi_of_device_match);
3436 return dev ? to_spi_device(dev) : NULL;
3437}
5f143af7
MF		 3438EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
3439#endif /* IS_ENABLED(CONFIG_OF) */
ce79d54a 3440
5f143af7 3441#if IS_ENABLED(CONFIG_OF_DYNAMIC)
8caab75f 3442static int __spi_of_controller_match(struct device *dev, const void *data)
ce79d54a
PA		 3443{
3444 return dev->of_node == data;
3445}
3446
8caab75f
GU		 3447/* the spi controllers are not using spi_bus, so we find it with another way */
3448static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
ce79d54a
PA		 3449{
3450 struct device *dev;
3451
3452 dev = class_find_device(&spi_master_class, NULL, node,
8caab75f 3453 __spi_of_controller_match);
6c364062
GU		 3454 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3455 dev = class_find_device(&spi_slave_class, NULL, node,
8caab75f 3456 __spi_of_controller_match);
ce79d54a
PA		 3457 if (!dev)
3458 return NULL;
3459
3460 /* reference got in class_find_device */
8caab75f 3461 return container_of(dev, struct spi_controller, dev);
ce79d54a
PA		 3462}
3463
3464static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3465 void *arg)
3466{
3467 struct of_reconfig_data *rd = arg;
8caab75f 3468 struct spi_controller *ctlr;
ce79d54a
PA		 3469 struct spi_device *spi;
3470
3471 switch (of_reconfig_get_state_change(action, arg)) {
3472 case OF_RECONFIG_CHANGE_ADD:
8caab75f
GU		 3473 ctlr = of_find_spi_controller_by_node(rd->dn->parent);
3474 if (ctlr == NULL)
ce79d54a
PA		 3475 return NOTIFY_OK; /* not for us */
3476
bd6c1644 3477 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
8caab75f 3478 put_device(&ctlr->dev);
bd6c1644
GU		 3479 return NOTIFY_OK;
3480 }
3481
8caab75f
GU		 3482 spi = of_register_spi_device(ctlr, rd->dn);
3483 put_device(&ctlr->dev);
ce79d54a
PA		 3484
3485 if (IS_ERR(spi)) {
25c56c88
RH		 3486 pr_err("%s: failed to create for '%pOF'\n",
3487 __func__, rd->dn);
e0af98a7 3488 of_node_clear_flag(rd->dn, OF_POPULATED);
ce79d54a
PA		 3489 return notifier_from_errno(PTR_ERR(spi));
3490 }
3491 break;
3492
3493 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3494 /* already depopulated? */
3495 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3496 return NOTIFY_OK;
3497
ce79d54a
PA		 3498 /* find our device by node */
3499 spi = of_find_spi_device_by_node(rd->dn);
3500 if (spi == NULL)
3501 return NOTIFY_OK; /* no? not meant for us */
3502
3503 /* unregister takes one ref away */
3504 spi_unregister_device(spi);
3505
3506 /* and put the reference of the find */
3507 put_device(&spi->dev);
3508 break;
3509 }
3510
3511 return NOTIFY_OK;
3512}
3513
3514static struct notifier_block spi_of_notifier = {
3515 .notifier_call = of_spi_notify,
3516};
3517#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3518extern struct notifier_block spi_of_notifier;
3519#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3520
7f24467f 3521#if IS_ENABLED(CONFIG_ACPI)
8caab75f 3522static int spi_acpi_controller_match(struct device *dev, const void *data)
7f24467f
OP		 3523{
3524 return ACPI_COMPANION(dev->parent) == data;
3525}
3526
3527static int spi_acpi_device_match(struct device *dev, void *data)
3528{
3529 return ACPI_COMPANION(dev) == data;
3530}
3531
8caab75f 3532static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
7f24467f
OP		 3533{
3534 struct device *dev;
3535
3536 dev = class_find_device(&spi_master_class, NULL, adev,
8caab75f 3537 spi_acpi_controller_match);
6c364062
GU		 3538 if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
3539 dev = class_find_device(&spi_slave_class, NULL, adev,
8caab75f 3540 spi_acpi_controller_match);
7f24467f
OP		 3541 if (!dev)
3542 return NULL;
3543
8caab75f 3544 return container_of(dev, struct spi_controller, dev);
7f24467f
OP		 3545}
3546
3547static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3548{
3549 struct device *dev;
3550
3551 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3552
3553 return dev ? to_spi_device(dev) : NULL;
3554}
3555
3556static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3557 void *arg)
3558{
3559 struct acpi_device *adev = arg;
8caab75f 3560 struct spi_controller *ctlr;
7f24467f
OP		 3561 struct spi_device *spi;
3562
3563 switch (value) {
3564 case ACPI_RECONFIG_DEVICE_ADD:
8caab75f
GU		 3565 ctlr = acpi_spi_find_controller_by_adev(adev->parent);
3566 if (!ctlr)
7f24467f
OP		 3567 break;
3568
8caab75f
GU		 3569 acpi_register_spi_device(ctlr, adev);
3570 put_device(&ctlr->dev);
7f24467f
OP		 3571 break;
3572 case ACPI_RECONFIG_DEVICE_REMOVE:
3573 if (!acpi_device_enumerated(adev))
3574 break;
3575
3576 spi = acpi_spi_find_device_by_adev(adev);
3577 if (!spi)
3578 break;
3579
3580 spi_unregister_device(spi);
3581 put_device(&spi->dev);
3582 break;
3583 }
3584
3585 return NOTIFY_OK;
3586}
3587
3588static struct notifier_block spi_acpi_notifier = {
3589 .notifier_call = acpi_spi_notify,
3590};
3591#else
3592extern struct notifier_block spi_acpi_notifier;
3593#endif
3594
8ae12a0d
DB		 3595static int __init spi_init(void)
3596{
b885244e
DB		 3597 int status;
3598
e94b1766 3599 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3600 if (!buf) {
3601 status = -ENOMEM;
3602 goto err0;
3603 }
3604
3605 status = bus_register(&spi_bus_type);
3606 if (status < 0)
3607 goto err1;
8ae12a0d 3608
b885244e
DB		 3609 status = class_register(&spi_master_class);
3610 if (status < 0)
3611 goto err2;
ce79d54a 3612
6c364062
GU		 3613 if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
3614 status = class_register(&spi_slave_class);
3615 if (status < 0)
3616 goto err3;
3617 }
3618
5267720e 3619 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a 3620 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
7f24467f
OP		 3621 if (IS_ENABLED(CONFIG_ACPI))
3622 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
ce79d54a 3623
8ae12a0d 3624 return 0;
b885244e 3625
6c364062
GU		 3626err3:
3627 class_unregister(&spi_master_class);
b885244e
DB		 3628err2:
3629 bus_unregister(&spi_bus_type);
3630err1:
3631 kfree(buf);
3632 buf = NULL;
3633err0:
3634 return status;
8ae12a0d 3635}
b885244e 3636
8ae12a0d
DB		 3637/* board_info is normally registered in arch_initcall(),
3638 * but even essential drivers wait till later
b885244e
DB		 3639 *
3640 * REVISIT only boardinfo really needs static linking. the rest (device and
3641 * driver registration) _could_ be dynamically linked (modular) ... costs
3642 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3643 */
673c0c00 3644postcore_initcall(spi_init);
8ae12a0d 3645
Linux 6.x block layer and io_uring tree(s)