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spi: Prevent unexpected SPI time out due to arithmetic overflow
[deliverable/linux.git] / drivers / spi / spi.c
CommitLineData
8ae12a0d 1/*
ca632f55 2 * SPI init/core code
8ae12a0d
DB		 3 *
4 * Copyright (C) 2005 David Brownell
d57a4282 5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
8ae12a0d
DB		 6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
8ae12a0d
DB		 16 */
17
8ae12a0d
DB		 18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/cache.h>
99adef31
MB		 22#include <linux/dma-mapping.h>
23#include <linux/dmaengine.h>
94040828 24#include <linux/mutex.h>
2b7a32f7 25#include <linux/of_device.h>
d57a4282 26#include <linux/of_irq.h>
86be408b 27#include <linux/clk/clk-conf.h>
5a0e3ad6 28#include <linux/slab.h>
e0626e38 29#include <linux/mod_devicetable.h>
8ae12a0d 30#include <linux/spi/spi.h>
74317984 31#include <linux/of_gpio.h>
3ae22e8c 32#include <linux/pm_runtime.h>
f48c767c 33#include <linux/pm_domain.h>
025ed130 34#include <linux/export.h>
8bd75c77 35#include <linux/sched/rt.h>
ffbbdd21
LW		 36#include <linux/delay.h>
37#include <linux/kthread.h>
64bee4d2
MW		 38#include <linux/ioport.h>
39#include <linux/acpi.h>
8ae12a0d 40
56ec1978
MB		 41#define CREATE_TRACE_POINTS
42#include <trace/events/spi.h>
43
8ae12a0d
DB		 44static void spidev_release(struct device *dev)
45{
0ffa0285 46 struct spi_device *spi = to_spi_device(dev);
8ae12a0d
DB		 47
48 /* spi masters may cleanup for released devices */
49 if (spi->master->cleanup)
50 spi->master->cleanup(spi);
51
0c868461 52 spi_master_put(spi->master);
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
eca2ebc7
MS		 70#define SPI_STATISTICS_ATTRS(field, file) \
71static ssize_t spi_master_##field##_show(struct device *dev, \
72 struct device_attribute *attr, \
73 char *buf) \
74{ \
75 struct spi_master *master = container_of(dev, \
76 struct spi_master, dev); \
77 return spi_statistics_##field##_show(&master->statistics, buf); \
78} \
79static struct device_attribute dev_attr_spi_master_##field = { \
80 .attr = { .name = file, .mode = S_IRUGO }, \
81 .show = spi_master_##field##_show, \
82}; \
83static ssize_t spi_device_##field##_show(struct device *dev, \
84 struct device_attribute *attr, \
85 char *buf) \
86{ \
d1eba93b 87 struct spi_device *spi = to_spi_device(dev); \
eca2ebc7
MS		 88 return spi_statistics_##field##_show(&spi->statistics, buf); \
89} \
90static struct device_attribute dev_attr_spi_device_##field = { \
91 .attr = { .name = file, .mode = S_IRUGO }, \
92 .show = spi_device_##field##_show, \
93}
94
95#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
96static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
97 char *buf) \
98{ \
99 unsigned long flags; \
100 ssize_t len; \
101 spin_lock_irqsave(&stat->lock, flags); \
102 len = sprintf(buf, format_string, stat->field); \
103 spin_unlock_irqrestore(&stat->lock, flags); \
104 return len; \
105} \
106SPI_STATISTICS_ATTRS(name, file)
107
108#define SPI_STATISTICS_SHOW(field, format_string) \
109 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
110 field, format_string)
111
112SPI_STATISTICS_SHOW(messages, "%lu");
113SPI_STATISTICS_SHOW(transfers, "%lu");
114SPI_STATISTICS_SHOW(errors, "%lu");
115SPI_STATISTICS_SHOW(timedout, "%lu");
116
117SPI_STATISTICS_SHOW(spi_sync, "%lu");
118SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
119SPI_STATISTICS_SHOW(spi_async, "%lu");
120
121SPI_STATISTICS_SHOW(bytes, "%llu");
122SPI_STATISTICS_SHOW(bytes_rx, "%llu");
123SPI_STATISTICS_SHOW(bytes_tx, "%llu");
124
6b7bc061
MS		 125#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
126 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
127 "transfer_bytes_histo_" number, \
128 transfer_bytes_histo[index], "%lu")
129SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
146
d9f12122
MS		 147SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
148
aa7da564
GKH		 149static struct attribute *spi_dev_attrs[] = {
150 &dev_attr_modalias.attr,
151 NULL,
8ae12a0d 152};
eca2ebc7
MS		 153
154static const struct attribute_group spi_dev_group = {
155 .attrs = spi_dev_attrs,
156};
157
158static struct attribute *spi_device_statistics_attrs[] = {
159 &dev_attr_spi_device_messages.attr,
160 &dev_attr_spi_device_transfers.attr,
161 &dev_attr_spi_device_errors.attr,
162 &dev_attr_spi_device_timedout.attr,
163 &dev_attr_spi_device_spi_sync.attr,
164 &dev_attr_spi_device_spi_sync_immediate.attr,
165 &dev_attr_spi_device_spi_async.attr,
166 &dev_attr_spi_device_bytes.attr,
167 &dev_attr_spi_device_bytes_rx.attr,
168 &dev_attr_spi_device_bytes_tx.attr,
6b7bc061
MS		 169 &dev_attr_spi_device_transfer_bytes_histo0.attr,
170 &dev_attr_spi_device_transfer_bytes_histo1.attr,
171 &dev_attr_spi_device_transfer_bytes_histo2.attr,
172 &dev_attr_spi_device_transfer_bytes_histo3.attr,
173 &dev_attr_spi_device_transfer_bytes_histo4.attr,
174 &dev_attr_spi_device_transfer_bytes_histo5.attr,
175 &dev_attr_spi_device_transfer_bytes_histo6.attr,
176 &dev_attr_spi_device_transfer_bytes_histo7.attr,
177 &dev_attr_spi_device_transfer_bytes_histo8.attr,
178 &dev_attr_spi_device_transfer_bytes_histo9.attr,
179 &dev_attr_spi_device_transfer_bytes_histo10.attr,
180 &dev_attr_spi_device_transfer_bytes_histo11.attr,
181 &dev_attr_spi_device_transfer_bytes_histo12.attr,
182 &dev_attr_spi_device_transfer_bytes_histo13.attr,
183 &dev_attr_spi_device_transfer_bytes_histo14.attr,
184 &dev_attr_spi_device_transfer_bytes_histo15.attr,
185 &dev_attr_spi_device_transfer_bytes_histo16.attr,
d9f12122 186 &dev_attr_spi_device_transfers_split_maxsize.attr,
eca2ebc7
MS		 187 NULL,
188};
189
190static const struct attribute_group spi_device_statistics_group = {
191 .name = "statistics",
192 .attrs = spi_device_statistics_attrs,
193};
194
195static const struct attribute_group *spi_dev_groups[] = {
196 &spi_dev_group,
197 &spi_device_statistics_group,
198 NULL,
199};
200
201static struct attribute *spi_master_statistics_attrs[] = {
202 &dev_attr_spi_master_messages.attr,
203 &dev_attr_spi_master_transfers.attr,
204 &dev_attr_spi_master_errors.attr,
205 &dev_attr_spi_master_timedout.attr,
206 &dev_attr_spi_master_spi_sync.attr,
207 &dev_attr_spi_master_spi_sync_immediate.attr,
208 &dev_attr_spi_master_spi_async.attr,
209 &dev_attr_spi_master_bytes.attr,
210 &dev_attr_spi_master_bytes_rx.attr,
211 &dev_attr_spi_master_bytes_tx.attr,
6b7bc061
MS		 212 &dev_attr_spi_master_transfer_bytes_histo0.attr,
213 &dev_attr_spi_master_transfer_bytes_histo1.attr,
214 &dev_attr_spi_master_transfer_bytes_histo2.attr,
215 &dev_attr_spi_master_transfer_bytes_histo3.attr,
216 &dev_attr_spi_master_transfer_bytes_histo4.attr,
217 &dev_attr_spi_master_transfer_bytes_histo5.attr,
218 &dev_attr_spi_master_transfer_bytes_histo6.attr,
219 &dev_attr_spi_master_transfer_bytes_histo7.attr,
220 &dev_attr_spi_master_transfer_bytes_histo8.attr,
221 &dev_attr_spi_master_transfer_bytes_histo9.attr,
222 &dev_attr_spi_master_transfer_bytes_histo10.attr,
223 &dev_attr_spi_master_transfer_bytes_histo11.attr,
224 &dev_attr_spi_master_transfer_bytes_histo12.attr,
225 &dev_attr_spi_master_transfer_bytes_histo13.attr,
226 &dev_attr_spi_master_transfer_bytes_histo14.attr,
227 &dev_attr_spi_master_transfer_bytes_histo15.attr,
228 &dev_attr_spi_master_transfer_bytes_histo16.attr,
d9f12122 229 &dev_attr_spi_master_transfers_split_maxsize.attr,
eca2ebc7
MS		 230 NULL,
231};
232
233static const struct attribute_group spi_master_statistics_group = {
234 .name = "statistics",
235 .attrs = spi_master_statistics_attrs,
236};
237
238static const struct attribute_group *spi_master_groups[] = {
239 &spi_master_statistics_group,
240 NULL,
241};
242
243void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
244 struct spi_transfer *xfer,
245 struct spi_master *master)
246{
247 unsigned long flags;
6b7bc061
MS		 248 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
249
250 if (l2len < 0)
251 l2len = 0;
eca2ebc7
MS		 252
253 spin_lock_irqsave(&stats->lock, flags);
254
255 stats->transfers++;
6b7bc061 256 stats->transfer_bytes_histo[l2len]++;
eca2ebc7
MS		 257
258 stats->bytes += xfer->len;
259 if ((xfer->tx_buf) &&
260 (xfer->tx_buf != master->dummy_tx))
261 stats->bytes_tx += xfer->len;
262 if ((xfer->rx_buf) &&
263 (xfer->rx_buf != master->dummy_rx))
264 stats->bytes_rx += xfer->len;
265
266 spin_unlock_irqrestore(&stats->lock, flags);
267}
268EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
8ae12a0d
DB		 269
270/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
272 */
273
75368bf6
AV		 274static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
275 const struct spi_device *sdev)
276{
277 while (id->name[0]) {
278 if (!strcmp(sdev->modalias, id->name))
279 return id;
280 id++;
281 }
282 return NULL;
283}
284
285const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
286{
287 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
288
289 return spi_match_id(sdrv->id_table, sdev);
290}
291EXPORT_SYMBOL_GPL(spi_get_device_id);
292
8ae12a0d
DB		 293static int spi_match_device(struct device *dev, struct device_driver *drv)
294{
295 const struct spi_device *spi = to_spi_device(dev);
75368bf6
AV		 296 const struct spi_driver *sdrv = to_spi_driver(drv);
297
2b7a32f7
SA		 298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev, drv))
300 return 1;
301
64bee4d2
MW		 302 /* Then try ACPI */
303 if (acpi_driver_match_device(dev, drv))
304 return 1;
305
75368bf6
AV		 306 if (sdrv->id_table)
307 return !!spi_match_id(sdrv->id_table, spi);
8ae12a0d 308
35f74fca 309 return strcmp(spi->modalias, drv->name) == 0;
8ae12a0d
DB		 310}
311
7eff2e7a 312static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
8ae12a0d
DB		 313{
314 const struct spi_device *spi = to_spi_device(dev);
8c4ff6d0
ZR		 315 int rc;
316
317 rc = acpi_device_uevent_modalias(dev, env);
318 if (rc != -ENODEV)
319 return rc;
8ae12a0d 320
e0626e38 321 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
8ae12a0d
DB		 322 return 0;
323}
324
8ae12a0d
DB		 325struct bus_type spi_bus_type = {
326 .name = "spi",
aa7da564 327 .dev_groups = spi_dev_groups,
8ae12a0d
DB		 328 .match = spi_match_device,
329 .uevent = spi_uevent,
8ae12a0d
DB		 330};
331EXPORT_SYMBOL_GPL(spi_bus_type);
332
b885244e
DB		 333
334static int spi_drv_probe(struct device *dev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
44af7927 337 struct spi_device *spi = to_spi_device(dev);
33cf00e5
MW		 338 int ret;
339
86be408b
SN		 340 ret = of_clk_set_defaults(dev->of_node, false);
341 if (ret)
342 return ret;
343
44af7927
JH		 344 if (dev->of_node) {
345 spi->irq = of_irq_get(dev->of_node, 0);
346 if (spi->irq == -EPROBE_DEFER)
347 return -EPROBE_DEFER;
348 if (spi->irq < 0)
349 spi->irq = 0;
350 }
351
676e7c25
UH		 352 ret = dev_pm_domain_attach(dev, true);
353 if (ret != -EPROBE_DEFER) {
44af7927 354 ret = sdrv->probe(spi);
676e7c25
UH		 355 if (ret)
356 dev_pm_domain_detach(dev, true);
357 }
b885244e 358
33cf00e5 359 return ret;
b885244e
DB		 360}
361
362static int spi_drv_remove(struct device *dev)
363{
364 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
33cf00e5
MW		 365 int ret;
366
aec35f4e 367 ret = sdrv->remove(to_spi_device(dev));
676e7c25 368 dev_pm_domain_detach(dev, true);
b885244e 369
33cf00e5 370 return ret;
b885244e
DB		 371}
372
373static void spi_drv_shutdown(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376
377 sdrv->shutdown(to_spi_device(dev));
378}
379
33e34dc6 380/**
ca5d2485 381 * __spi_register_driver - register a SPI driver
88c9321d 382 * @owner: owner module of the driver to register
33e34dc6
DB		 383 * @sdrv: the driver to register
384 * Context: can sleep
97d56dc6
JMC		 385 *
386 * Return: zero on success, else a negative error code.
33e34dc6 387 */
ca5d2485 388int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
b885244e 389{
ca5d2485 390 sdrv->driver.owner = owner;
b885244e
DB		 391 sdrv->driver.bus = &spi_bus_type;
392 if (sdrv->probe)
393 sdrv->driver.probe = spi_drv_probe;
394 if (sdrv->remove)
395 sdrv->driver.remove = spi_drv_remove;
396 if (sdrv->shutdown)
397 sdrv->driver.shutdown = spi_drv_shutdown;
398 return driver_register(&sdrv->driver);
399}
ca5d2485 400EXPORT_SYMBOL_GPL(__spi_register_driver);
b885244e 401
8ae12a0d
DB		 402/*-------------------------------------------------------------------------*/
403
404/* SPI devices should normally not be created by SPI device drivers; that
405 * would make them board-specific. Similarly with SPI master drivers.
406 * Device registration normally goes into like arch/.../mach.../board-YYY.c
407 * with other readonly (flashable) information about mainboard devices.
408 */
409
410struct boardinfo {
411 struct list_head list;
2b9603a0 412 struct spi_board_info board_info;
8ae12a0d
DB		 413};
414
415static LIST_HEAD(board_list);
2b9603a0
FT		 416static LIST_HEAD(spi_master_list);
417
418/*
419 * Used to protect add/del opertion for board_info list and
420 * spi_master list, and their matching process
421 */
94040828 422static DEFINE_MUTEX(board_lock);
8ae12a0d 423
dc87c98e
GL		 424/**
425 * spi_alloc_device - Allocate a new SPI device
426 * @master: Controller to which device is connected
427 * Context: can sleep
428 *
429 * Allows a driver to allocate and initialize a spi_device without
430 * registering it immediately. This allows a driver to directly
431 * fill the spi_device with device parameters before calling
432 * spi_add_device() on it.
433 *
434 * Caller is responsible to call spi_add_device() on the returned
435 * spi_device structure to add it to the SPI master. If the caller
436 * needs to discard the spi_device without adding it, then it should
437 * call spi_dev_put() on it.
438 *
97d56dc6 439 * Return: a pointer to the new device, or NULL.
dc87c98e
GL		 440 */
441struct spi_device *spi_alloc_device(struct spi_master *master)
442{
443 struct spi_device *spi;
dc87c98e
GL		 444
445 if (!spi_master_get(master))
446 return NULL;
447
5fe5f05e 448 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
dc87c98e 449 if (!spi) {
dc87c98e
GL		 450 spi_master_put(master);
451 return NULL;
452 }
453
454 spi->master = master;
178db7d3 455 spi->dev.parent = &master->dev;
dc87c98e
GL		 456 spi->dev.bus = &spi_bus_type;
457 spi->dev.release = spidev_release;
446411e1 458 spi->cs_gpio = -ENOENT;
eca2ebc7
MS		 459
460 spin_lock_init(&spi->statistics.lock);
461
dc87c98e
GL		 462 device_initialize(&spi->dev);
463 return spi;
464}
465EXPORT_SYMBOL_GPL(spi_alloc_device);
466
e13ac47b
JN		 467static void spi_dev_set_name(struct spi_device *spi)
468{
469 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
470
471 if (adev) {
472 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
473 return;
474 }
475
476 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
477 spi->chip_select);
478}
479
b6fb8d3a
MW		 480static int spi_dev_check(struct device *dev, void *data)
481{
482 struct spi_device *spi = to_spi_device(dev);
483 struct spi_device *new_spi = data;
484
485 if (spi->master == new_spi->master &&
486 spi->chip_select == new_spi->chip_select)
487 return -EBUSY;
488 return 0;
489}
490
dc87c98e
GL		 491/**
492 * spi_add_device - Add spi_device allocated with spi_alloc_device
493 * @spi: spi_device to register
494 *
495 * Companion function to spi_alloc_device. Devices allocated with
496 * spi_alloc_device can be added onto the spi bus with this function.
497 *
97d56dc6 498 * Return: 0 on success; negative errno on failure
dc87c98e
GL		 499 */
500int spi_add_device(struct spi_device *spi)
501{
e48880e0 502 static DEFINE_MUTEX(spi_add_lock);
74317984
JCPV		 503 struct spi_master *master = spi->master;
504 struct device *dev = master->dev.parent;
dc87c98e
GL		 505 int status;
506
507 /* Chipselects are numbered 0..max; validate. */
74317984 508 if (spi->chip_select >= master->num_chipselect) {
dc87c98e
GL		 509 dev_err(dev, "cs%d >= max %d\n",
510 spi->chip_select,
74317984 511 master->num_chipselect);
dc87c98e
GL		 512 return -EINVAL;
513 }
514
515 /* Set the bus ID string */
e13ac47b 516 spi_dev_set_name(spi);
e48880e0
DB		 517
518 /* We need to make sure there's no other device with this
519 * chipselect **BEFORE** we call setup(), else we'll trash
520 * its configuration. Lock against concurrent add() calls.
521 */
522 mutex_lock(&spi_add_lock);
523
b6fb8d3a
MW		 524 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
525 if (status) {
e48880e0
DB		 526 dev_err(dev, "chipselect %d already in use\n",
527 spi->chip_select);
e48880e0
DB		 528 goto done;
529 }
530
74317984
JCPV		 531 if (master->cs_gpios)
532 spi->cs_gpio = master->cs_gpios[spi->chip_select];
533
e48880e0
DB		 534 /* Drivers may modify this initial i/o setup, but will
535 * normally rely on the device being setup. Devices
536 * using SPI_CS_HIGH can't coexist well otherwise...
537 */
7d077197 538 status = spi_setup(spi);
dc87c98e 539 if (status < 0) {
eb288a1f
LW		 540 dev_err(dev, "can't setup %s, status %d\n",
541 dev_name(&spi->dev), status);
e48880e0 542 goto done;
dc87c98e
GL		 543 }
544
e48880e0 545 /* Device may be bound to an active driver when this returns */
dc87c98e 546 status = device_add(&spi->dev);
e48880e0 547 if (status < 0)
eb288a1f
LW		 548 dev_err(dev, "can't add %s, status %d\n",
549 dev_name(&spi->dev), status);
e48880e0 550 else
35f74fca 551 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
dc87c98e 552
e48880e0
DB		 553done:
554 mutex_unlock(&spi_add_lock);
555 return status;
dc87c98e
GL		 556}
557EXPORT_SYMBOL_GPL(spi_add_device);
8ae12a0d 558
33e34dc6
DB		 559/**
560 * spi_new_device - instantiate one new SPI device
561 * @master: Controller to which device is connected
562 * @chip: Describes the SPI device
563 * Context: can sleep
564 *
565 * On typical mainboards, this is purely internal; and it's not needed
8ae12a0d
DB		 566 * after board init creates the hard-wired devices. Some development
567 * platforms may not be able to use spi_register_board_info though, and
568 * this is exported so that for example a USB or parport based adapter
569 * driver could add devices (which it would learn about out-of-band).
082c8cb4 570 *
97d56dc6 571 * Return: the new device, or NULL.
8ae12a0d 572 */
e9d5a461
AB		 573struct spi_device *spi_new_device(struct spi_master *master,
574 struct spi_board_info *chip)
8ae12a0d
DB		 575{
576 struct spi_device *proxy;
8ae12a0d
DB		 577 int status;
578
082c8cb4
DB		 579 /* NOTE: caller did any chip->bus_num checks necessary.
580 *
581 * Also, unless we change the return value convention to use
582 * error-or-pointer (not NULL-or-pointer), troubleshootability
583 * suggests syslogged diagnostics are best here (ugh).
584 */
585
dc87c98e
GL		 586 proxy = spi_alloc_device(master);
587 if (!proxy)
8ae12a0d
DB		 588 return NULL;
589
102eb975
GL		 590 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
591
8ae12a0d
DB		 592 proxy->chip_select = chip->chip_select;
593 proxy->max_speed_hz = chip->max_speed_hz;
980a01c9 594 proxy->mode = chip->mode;
8ae12a0d 595 proxy->irq = chip->irq;
102eb975 596 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
8ae12a0d
DB		 597 proxy->dev.platform_data = (void *) chip->platform_data;
598 proxy->controller_data = chip->controller_data;
599 proxy->controller_state = NULL;
8ae12a0d 600
dc87c98e 601 status = spi_add_device(proxy);
8ae12a0d 602 if (status < 0) {
dc87c98e
GL		 603 spi_dev_put(proxy);
604 return NULL;
8ae12a0d
DB		 605 }
606
8ae12a0d
DB		 607 return proxy;
608}
609EXPORT_SYMBOL_GPL(spi_new_device);
610
3b1884c2
GU		 611/**
612 * spi_unregister_device - unregister a single SPI device
613 * @spi: spi_device to unregister
614 *
615 * Start making the passed SPI device vanish. Normally this would be handled
616 * by spi_unregister_master().
617 */
618void spi_unregister_device(struct spi_device *spi)
619{
bd6c1644
GU		 620 if (!spi)
621 return;
622
623 if (spi->dev.of_node)
624 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
7f24467f
OP		 625 if (ACPI_COMPANION(&spi->dev))
626 acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
bd6c1644 627 device_unregister(&spi->dev);
3b1884c2
GU		 628}
629EXPORT_SYMBOL_GPL(spi_unregister_device);
630
2b9603a0
FT		 631static void spi_match_master_to_boardinfo(struct spi_master *master,
632 struct spi_board_info *bi)
633{
634 struct spi_device *dev;
635
636 if (master->bus_num != bi->bus_num)
637 return;
638
639 dev = spi_new_device(master, bi);
640 if (!dev)
641 dev_err(master->dev.parent, "can't create new device for %s\n",
642 bi->modalias);
643}
644
33e34dc6
DB		 645/**
646 * spi_register_board_info - register SPI devices for a given board
647 * @info: array of chip descriptors
648 * @n: how many descriptors are provided
649 * Context: can sleep
650 *
8ae12a0d
DB		 651 * Board-specific early init code calls this (probably during arch_initcall)
652 * with segments of the SPI device table. Any device nodes are created later,
653 * after the relevant parent SPI controller (bus_num) is defined. We keep
654 * this table of devices forever, so that reloading a controller driver will
655 * not make Linux forget about these hard-wired devices.
656 *
657 * Other code can also call this, e.g. a particular add-on board might provide
658 * SPI devices through its expansion connector, so code initializing that board
659 * would naturally declare its SPI devices.
660 *
661 * The board info passed can safely be __initdata ... but be careful of
662 * any embedded pointers (platform_data, etc), they're copied as-is.
97d56dc6
JMC		 663 *
664 * Return: zero on success, else a negative error code.
8ae12a0d 665 */
fd4a319b 666int spi_register_board_info(struct spi_board_info const *info, unsigned n)
8ae12a0d 667{
2b9603a0
FT		 668 struct boardinfo *bi;
669 int i;
8ae12a0d 670
c7908a37
XL		 671 if (!n)
672 return -EINVAL;
673
2b9603a0 674 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
8ae12a0d
DB		 675 if (!bi)
676 return -ENOMEM;
8ae12a0d 677
2b9603a0
FT		 678 for (i = 0; i < n; i++, bi++, info++) {
679 struct spi_master *master;
8ae12a0d 680
2b9603a0
FT		 681 memcpy(&bi->board_info, info, sizeof(*info));
682 mutex_lock(&board_lock);
683 list_add_tail(&bi->list, &board_list);
684 list_for_each_entry(master, &spi_master_list, list)
685 spi_match_master_to_boardinfo(master, &bi->board_info);
686 mutex_unlock(&board_lock);
8ae12a0d 687 }
2b9603a0
FT		 688
689 return 0;
8ae12a0d
DB		 690}
691
692/*-------------------------------------------------------------------------*/
693
b158935f
MB		 694static void spi_set_cs(struct spi_device *spi, bool enable)
695{
696 if (spi->mode & SPI_CS_HIGH)
697 enable = !enable;
698
243f07be 699 if (gpio_is_valid(spi->cs_gpio))
b158935f
MB		 700 gpio_set_value(spi->cs_gpio, !enable);
701 else if (spi->master->set_cs)
702 spi->master->set_cs(spi, !enable);
703}
704
2de440f5 705#ifdef CONFIG_HAS_DMA
6ad45a27
MB		 706static int spi_map_buf(struct spi_master *master, struct device *dev,
707 struct sg_table *sgt, void *buf, size_t len,
708 enum dma_data_direction dir)
709{
710 const bool vmalloced_buf = is_vmalloc_addr(buf);
df88e91b 711 unsigned int max_seg_size = dma_get_max_seg_size(dev);
65598c13
AG		 712 int desc_len;
713 int sgs;
6ad45a27
MB		 714 struct page *vm_page;
715 void *sg_buf;
716 size_t min;
717 int i, ret;
718
65598c13 719 if (vmalloced_buf) {
df88e91b 720 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
65598c13 721 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
0569a88f 722 } else if (virt_addr_valid(buf)) {
df88e91b 723 desc_len = min_t(int, max_seg_size, master->max_dma_len);
65598c13 724 sgs = DIV_ROUND_UP(len, desc_len);
0569a88f
V		 725 } else {
726 return -EINVAL;
65598c13
AG		 727 }
728
6ad45a27
MB		 729 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
730 if (ret != 0)
731 return ret;
732
733 for (i = 0; i < sgs; i++) {
6ad45a27
MB		 734
735 if (vmalloced_buf) {
65598c13
AG		 736 min = min_t(size_t,
737 len, desc_len - offset_in_page(buf));
6ad45a27
MB		 738 vm_page = vmalloc_to_page(buf);
739 if (!vm_page) {
740 sg_free_table(sgt);
741 return -ENOMEM;
742 }
c1aefbdd
CK		 743 sg_set_page(&sgt->sgl[i], vm_page,
744 min, offset_in_page(buf));
6ad45a27 745 } else {
65598c13 746 min = min_t(size_t, len, desc_len);
6ad45a27 747 sg_buf = buf;
c1aefbdd 748 sg_set_buf(&sgt->sgl[i], sg_buf, min);
6ad45a27
MB		 749 }
750
6ad45a27
MB		 751 buf += min;
752 len -= min;
753 }
754
755 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
89e4b66a
GU		 756 if (!ret)
757 ret = -ENOMEM;
6ad45a27
MB		 758 if (ret < 0) {
759 sg_free_table(sgt);
760 return ret;
761 }
762
763 sgt->nents = ret;
764
765 return 0;
766}
767
768static void spi_unmap_buf(struct spi_master *master, struct device *dev,
769 struct sg_table *sgt, enum dma_data_direction dir)
770{
771 if (sgt->orig_nents) {
772 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
773 sg_free_table(sgt);
774 }
775}
776
2de440f5 777static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
99adef31 778{
99adef31
MB		 779 struct device *tx_dev, *rx_dev;
780 struct spi_transfer *xfer;
6ad45a27 781 int ret;
3a2eba9b 782
6ad45a27 783 if (!master->can_dma)
99adef31
MB		 784 return 0;
785
c37f45b5
LL		 786 if (master->dma_tx)
787 tx_dev = master->dma_tx->device->dev;
788 else
789 tx_dev = &master->dev;
790
791 if (master->dma_rx)
792 rx_dev = master->dma_rx->device->dev;
793 else
794 rx_dev = &master->dev;
99adef31
MB		 795
796 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
797 if (!master->can_dma(master, msg->spi, xfer))
798 continue;
799
800 if (xfer->tx_buf != NULL) {
6ad45a27
MB		 801 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
802 (void *)xfer->tx_buf, xfer->len,
803 DMA_TO_DEVICE);
804 if (ret != 0)
805 return ret;
99adef31
MB		 806 }
807
808 if (xfer->rx_buf != NULL) {
6ad45a27
MB		 809 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
810 xfer->rx_buf, xfer->len,
811 DMA_FROM_DEVICE);
812 if (ret != 0) {
813 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
814 DMA_TO_DEVICE);
815 return ret;
99adef31
MB		 816 }
817 }
818 }
819
820 master->cur_msg_mapped = true;
821
822 return 0;
823}
824
4b786458 825static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
99adef31
MB		 826{
827 struct spi_transfer *xfer;
828 struct device *tx_dev, *rx_dev;
829
6ad45a27 830 if (!master->cur_msg_mapped || !master->can_dma)
99adef31
MB		 831 return 0;
832
c37f45b5
LL		 833 if (master->dma_tx)
834 tx_dev = master->dma_tx->device->dev;
835 else
836 tx_dev = &master->dev;
837
838 if (master->dma_rx)
839 rx_dev = master->dma_rx->device->dev;
840 else
841 rx_dev = &master->dev;
99adef31
MB		 842
843 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
844 if (!master->can_dma(master, msg->spi, xfer))
845 continue;
846
6ad45a27
MB		 847 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
848 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
99adef31
MB		 849 }
850
851 return 0;
852}
2de440f5 853#else /* !CONFIG_HAS_DMA */
f4502dd1
V		 854static inline int spi_map_buf(struct spi_master *master,
855 struct device *dev, struct sg_table *sgt,
856 void *buf, size_t len,
857 enum dma_data_direction dir)
858{
859 return -EINVAL;
860}
861
862static inline void spi_unmap_buf(struct spi_master *master,
863 struct device *dev, struct sg_table *sgt,
864 enum dma_data_direction dir)
865{
866}
867
2de440f5
GU		 868static inline int __spi_map_msg(struct spi_master *master,
869 struct spi_message *msg)
870{
871 return 0;
872}
873
4b786458
MS		 874static inline int __spi_unmap_msg(struct spi_master *master,
875 struct spi_message *msg)
2de440f5
GU		 876{
877 return 0;
878}
879#endif /* !CONFIG_HAS_DMA */
880
4b786458
MS		 881static inline int spi_unmap_msg(struct spi_master *master,
882 struct spi_message *msg)
883{
884 struct spi_transfer *xfer;
885
886 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
887 /*
888 * Restore the original value of tx_buf or rx_buf if they are
889 * NULL.
890 */
891 if (xfer->tx_buf == master->dummy_tx)
892 xfer->tx_buf = NULL;
893 if (xfer->rx_buf == master->dummy_rx)
894 xfer->rx_buf = NULL;
895 }
896
897 return __spi_unmap_msg(master, msg);
898}
899
2de440f5
GU		 900static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
901{
902 struct spi_transfer *xfer;
903 void *tmp;
904 unsigned int max_tx, max_rx;
905
906 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
907 max_tx = 0;
908 max_rx = 0;
909
910 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
911 if ((master->flags & SPI_MASTER_MUST_TX) &&
912 !xfer->tx_buf)
913 max_tx = max(xfer->len, max_tx);
914 if ((master->flags & SPI_MASTER_MUST_RX) &&
915 !xfer->rx_buf)
916 max_rx = max(xfer->len, max_rx);
917 }
918
919 if (max_tx) {
920 tmp = krealloc(master->dummy_tx, max_tx,
921 GFP_KERNEL | GFP_DMA);
922 if (!tmp)
923 return -ENOMEM;
924 master->dummy_tx = tmp;
925 memset(tmp, 0, max_tx);
926 }
927
928 if (max_rx) {
929 tmp = krealloc(master->dummy_rx, max_rx,
930 GFP_KERNEL | GFP_DMA);
931 if (!tmp)
932 return -ENOMEM;
933 master->dummy_rx = tmp;
934 }
935
936 if (max_tx || max_rx) {
937 list_for_each_entry(xfer, &msg->transfers,
938 transfer_list) {
939 if (!xfer->tx_buf)
940 xfer->tx_buf = master->dummy_tx;
941 if (!xfer->rx_buf)
942 xfer->rx_buf = master->dummy_rx;
943 }
944 }
945 }
946
947 return __spi_map_msg(master, msg);
948}
99adef31 949
b158935f
MB		 950/*
951 * spi_transfer_one_message - Default implementation of transfer_one_message()
952 *
953 * This is a standard implementation of transfer_one_message() for
8ba811a7 954 * drivers which implement a transfer_one() operation. It provides
b158935f
MB		 955 * standard handling of delays and chip select management.
956 */
957static int spi_transfer_one_message(struct spi_master *master,
958 struct spi_message *msg)
959{
960 struct spi_transfer *xfer;
b158935f
MB		 961 bool keep_cs = false;
962 int ret = 0;
d0716dde 963 unsigned long long ms = 1;
eca2ebc7
MS		 964 struct spi_statistics *statm = &master->statistics;
965 struct spi_statistics *stats = &msg->spi->statistics;
b158935f
MB		 966
967 spi_set_cs(msg->spi, true);
968
eca2ebc7
MS		 969 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
970 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
971
b158935f
MB		 972 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
973 trace_spi_transfer_start(msg, xfer);
974
eca2ebc7
MS		 975 spi_statistics_add_transfer_stats(statm, xfer, master);
976 spi_statistics_add_transfer_stats(stats, xfer, master);
977
38ec10f6
MB		 978 if (xfer->tx_buf || xfer->rx_buf) {
979 reinit_completion(&master->xfer_completion);
b158935f 980
38ec10f6
MB		 981 ret = master->transfer_one(master, msg->spi, xfer);
982 if (ret < 0) {
eca2ebc7
MS		 983 SPI_STATISTICS_INCREMENT_FIELD(statm,
984 errors);
985 SPI_STATISTICS_INCREMENT_FIELD(stats,
986 errors);
38ec10f6
MB		 987 dev_err(&msg->spi->dev,
988 "SPI transfer failed: %d\n", ret);
989 goto out;
990 }
b158935f 991
38ec10f6
MB		 992 if (ret > 0) {
993 ret = 0;
d0716dde
SW		 994 ms = 8LL * 1000LL * xfer->len;
995 do_div(ms, xfer->speed_hz);
38ec10f6 996 ms += ms + 100; /* some tolerance */
16a0ce4e 997
d0716dde
SW		 998 if (ms > UINT_MAX)
999 ms = UINT_MAX;
1000
38ec10f6
MB		 1001 ms = wait_for_completion_timeout(&master->xfer_completion,
1002 msecs_to_jiffies(ms));
1003 }
16a0ce4e 1004
38ec10f6 1005 if (ms == 0) {
eca2ebc7
MS		 1006 SPI_STATISTICS_INCREMENT_FIELD(statm,
1007 timedout);
1008 SPI_STATISTICS_INCREMENT_FIELD(stats,
1009 timedout);
38ec10f6
MB		 1010 dev_err(&msg->spi->dev,
1011 "SPI transfer timed out\n");
1012 msg->status = -ETIMEDOUT;
1013 }
1014 } else {
1015 if (xfer->len)
1016 dev_err(&msg->spi->dev,
1017 "Bufferless transfer has length %u\n",
1018 xfer->len);
13a42798 1019 }
b158935f
MB		 1020
1021 trace_spi_transfer_stop(msg, xfer);
1022
1023 if (msg->status != -EINPROGRESS)
1024 goto out;
1025
1026 if (xfer->delay_usecs)
1027 udelay(xfer->delay_usecs);
1028
1029 if (xfer->cs_change) {
1030 if (list_is_last(&xfer->transfer_list,
1031 &msg->transfers)) {
1032 keep_cs = true;
1033 } else {
0b73aa63
MB		 1034 spi_set_cs(msg->spi, false);
1035 udelay(10);
1036 spi_set_cs(msg->spi, true);
b158935f
MB		 1037 }
1038 }
1039
1040 msg->actual_length += xfer->len;
1041 }
1042
1043out:
1044 if (ret != 0 || !keep_cs)
1045 spi_set_cs(msg->spi, false);
1046
1047 if (msg->status == -EINPROGRESS)
1048 msg->status = ret;
1049
ff61eb42 1050 if (msg->status && master->handle_err)
b716c4ff
AS		 1051 master->handle_err(master, msg);
1052
d780c371
MS		 1053 spi_res_release(master, msg);
1054
b158935f
MB		 1055 spi_finalize_current_message(master);
1056
1057 return ret;
1058}
1059
1060/**
1061 * spi_finalize_current_transfer - report completion of a transfer
2c675689 1062 * @master: the master reporting completion
b158935f
MB		 1063 *
1064 * Called by SPI drivers using the core transfer_one_message()
1065 * implementation to notify it that the current interrupt driven
9e8f4882 1066 * transfer has finished and the next one may be scheduled.
b158935f
MB		 1067 */
1068void spi_finalize_current_transfer(struct spi_master *master)
1069{
1070 complete(&master->xfer_completion);
1071}
1072EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1073
ffbbdd21 1074/**
fc9e0f71
MB		 1075 * __spi_pump_messages - function which processes spi message queue
1076 * @master: master to process queue for
1077 * @in_kthread: true if we are in the context of the message pump thread
ffbbdd21
LW		 1078 *
1079 * This function checks if there is any spi message in the queue that
1080 * needs processing and if so call out to the driver to initialize hardware
1081 * and transfer each message.
1082 *
0461a414
MB		 1083 * Note that it is called both from the kthread itself and also from
1084 * inside spi_sync(); the queue extraction handling at the top of the
1085 * function should deal with this safely.
ffbbdd21 1086 */
ef4d96ec 1087static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
ffbbdd21 1088{
ffbbdd21
LW		 1089 unsigned long flags;
1090 bool was_busy = false;
1091 int ret;
1092
983aee5d 1093 /* Lock queue */
ffbbdd21 1094 spin_lock_irqsave(&master->queue_lock, flags);
983aee5d
MB		 1095
1096 /* Make sure we are not already running a message */
1097 if (master->cur_msg) {
1098 spin_unlock_irqrestore(&master->queue_lock, flags);
1099 return;
1100 }
1101
0461a414
MB		 1102 /* If another context is idling the device then defer */
1103 if (master->idling) {
1104 queue_kthread_work(&master->kworker, &master->pump_messages);
1105 spin_unlock_irqrestore(&master->queue_lock, flags);
1106 return;
1107 }
1108
983aee5d 1109 /* Check if the queue is idle */
ffbbdd21 1110 if (list_empty(&master->queue) || !master->running) {
b0b36b86
BF		 1111 if (!master->busy) {
1112 spin_unlock_irqrestore(&master->queue_lock, flags);
1113 return;
ffbbdd21 1114 }
fc9e0f71
MB		 1115
1116 /* Only do teardown in the thread */
1117 if (!in_kthread) {
1118 queue_kthread_work(&master->kworker,
1119 &master->pump_messages);
1120 spin_unlock_irqrestore(&master->queue_lock, flags);
1121 return;
1122 }
1123
ffbbdd21 1124 master->busy = false;
0461a414 1125 master->idling = true;
ffbbdd21 1126 spin_unlock_irqrestore(&master->queue_lock, flags);
0461a414 1127
3a2eba9b
MB		 1128 kfree(master->dummy_rx);
1129 master->dummy_rx = NULL;
1130 kfree(master->dummy_tx);
1131 master->dummy_tx = NULL;
b0b36b86
BF		 1132 if (master->unprepare_transfer_hardware &&
1133 master->unprepare_transfer_hardware(master))
1134 dev_err(&master->dev,
1135 "failed to unprepare transfer hardware\n");
49834de2
MB		 1136 if (master->auto_runtime_pm) {
1137 pm_runtime_mark_last_busy(master->dev.parent);
1138 pm_runtime_put_autosuspend(master->dev.parent);
1139 }
56ec1978 1140 trace_spi_master_idle(master);
ffbbdd21 1141
0461a414
MB		 1142 spin_lock_irqsave(&master->queue_lock, flags);
1143 master->idling = false;
ffbbdd21
LW		 1144 spin_unlock_irqrestore(&master->queue_lock, flags);
1145 return;
1146 }
ffbbdd21 1147
ffbbdd21
LW		 1148 /* Extract head of queue */
1149 master->cur_msg =
a89e2d27 1150 list_first_entry(&master->queue, struct spi_message, queue);
ffbbdd21
LW		 1151
1152 list_del_init(&master->cur_msg->queue);
1153 if (master->busy)
1154 was_busy = true;
1155 else
1156 master->busy = true;
1157 spin_unlock_irqrestore(&master->queue_lock, flags);
1158
ef4d96ec
MB		 1159 mutex_lock(&master->io_mutex);
1160
49834de2
MB		 1161 if (!was_busy && master->auto_runtime_pm) {
1162 ret = pm_runtime_get_sync(master->dev.parent);
1163 if (ret < 0) {
1164 dev_err(&master->dev, "Failed to power device: %d\n",
1165 ret);
1166 return;
1167 }
1168 }
1169
56ec1978
MB		 1170 if (!was_busy)
1171 trace_spi_master_busy(master);
1172
7dfd2bd7 1173 if (!was_busy && master->prepare_transfer_hardware) {
ffbbdd21
LW		 1174 ret = master->prepare_transfer_hardware(master);
1175 if (ret) {
1176 dev_err(&master->dev,
1177 "failed to prepare transfer hardware\n");
49834de2
MB		 1178
1179 if (master->auto_runtime_pm)
1180 pm_runtime_put(master->dev.parent);
ffbbdd21
LW		 1181 return;
1182 }
1183 }
1184
56ec1978
MB		 1185 trace_spi_message_start(master->cur_msg);
1186
2841a5fc
MB		 1187 if (master->prepare_message) {
1188 ret = master->prepare_message(master, master->cur_msg);
1189 if (ret) {
1190 dev_err(&master->dev,
1191 "failed to prepare message: %d\n", ret);
1192 master->cur_msg->status = ret;
1193 spi_finalize_current_message(master);
49023d2e 1194 goto out;
2841a5fc
MB		 1195 }
1196 master->cur_msg_prepared = true;
1197 }
1198
99adef31
MB		 1199 ret = spi_map_msg(master, master->cur_msg);
1200 if (ret) {
1201 master->cur_msg->status = ret;
1202 spi_finalize_current_message(master);
49023d2e 1203 goto out;
99adef31
MB		 1204 }
1205
ffbbdd21
LW		 1206 ret = master->transfer_one_message(master, master->cur_msg);
1207 if (ret) {
1208 dev_err(&master->dev,
1f802f82 1209 "failed to transfer one message from queue\n");
49023d2e 1210 goto out;
ffbbdd21 1211 }
49023d2e
JH		 1212
1213out:
ef4d96ec 1214 mutex_unlock(&master->io_mutex);
62826970
MB		 1215
1216 /* Prod the scheduler in case transfer_one() was busy waiting */
49023d2e
JH		 1217 if (!ret)
1218 cond_resched();
ffbbdd21
LW		 1219}
1220
fc9e0f71
MB		 1221/**
1222 * spi_pump_messages - kthread work function which processes spi message queue
1223 * @work: pointer to kthread work struct contained in the master struct
1224 */
1225static void spi_pump_messages(struct kthread_work *work)
1226{
1227 struct spi_master *master =
1228 container_of(work, struct spi_master, pump_messages);
1229
ef4d96ec 1230 __spi_pump_messages(master, true);
fc9e0f71
MB		 1231}
1232
ffbbdd21
LW		 1233static int spi_init_queue(struct spi_master *master)
1234{
1235 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1236
ffbbdd21
LW		 1237 master->running = false;
1238 master->busy = false;
1239
1240 init_kthread_worker(&master->kworker);
1241 master->kworker_task = kthread_run(kthread_worker_fn,
f170168b 1242 &master->kworker, "%s",
ffbbdd21
LW		 1243 dev_name(&master->dev));
1244 if (IS_ERR(master->kworker_task)) {
1245 dev_err(&master->dev, "failed to create message pump task\n");
98a8f5a0 1246 return PTR_ERR(master->kworker_task);
ffbbdd21
LW		 1247 }
1248 init_kthread_work(&master->pump_messages, spi_pump_messages);
1249
1250 /*
1251 * Master config will indicate if this controller should run the
1252 * message pump with high (realtime) priority to reduce the transfer
1253 * latency on the bus by minimising the delay between a transfer
1254 * request and the scheduling of the message pump thread. Without this
1255 * setting the message pump thread will remain at default priority.
1256 */
1257 if (master->rt) {
1258 dev_info(&master->dev,
1259 "will run message pump with realtime priority\n");
1260 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1261 }
1262
1263 return 0;
1264}
1265
1266/**
1267 * spi_get_next_queued_message() - called by driver to check for queued
1268 * messages
1269 * @master: the master to check for queued messages
1270 *
1271 * If there are more messages in the queue, the next message is returned from
1272 * this call.
97d56dc6
JMC		 1273 *
1274 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21
LW		 1275 */
1276struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1277{
1278 struct spi_message *next;
1279 unsigned long flags;
1280
1281 /* get a pointer to the next message, if any */
1282 spin_lock_irqsave(&master->queue_lock, flags);
1cfd97f9
AL		 1283 next = list_first_entry_or_null(&master->queue, struct spi_message,
1284 queue);
ffbbdd21
LW		 1285 spin_unlock_irqrestore(&master->queue_lock, flags);
1286
1287 return next;
1288}
1289EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1290
1291/**
1292 * spi_finalize_current_message() - the current message is complete
1293 * @master: the master to return the message to
1294 *
1295 * Called by the driver to notify the core that the message in the front of the
1296 * queue is complete and can be removed from the queue.
1297 */
1298void spi_finalize_current_message(struct spi_master *master)
1299{
1300 struct spi_message *mesg;
1301 unsigned long flags;
2841a5fc 1302 int ret;
ffbbdd21
LW		 1303
1304 spin_lock_irqsave(&master->queue_lock, flags);
1305 mesg = master->cur_msg;
ffbbdd21
LW		 1306 spin_unlock_irqrestore(&master->queue_lock, flags);
1307
99adef31
MB		 1308 spi_unmap_msg(master, mesg);
1309
2841a5fc
MB		 1310 if (master->cur_msg_prepared && master->unprepare_message) {
1311 ret = master->unprepare_message(master, mesg);
1312 if (ret) {
1313 dev_err(&master->dev,
1314 "failed to unprepare message: %d\n", ret);
1315 }
1316 }
391949b6 1317
8e76ef88
MS		 1318 spin_lock_irqsave(&master->queue_lock, flags);
1319 master->cur_msg = NULL;
2841a5fc 1320 master->cur_msg_prepared = false;
8e76ef88
MS		 1321 queue_kthread_work(&master->kworker, &master->pump_messages);
1322 spin_unlock_irqrestore(&master->queue_lock, flags);
1323
1324 trace_spi_message_done(mesg);
2841a5fc 1325
ffbbdd21
LW		 1326 mesg->state = NULL;
1327 if (mesg->complete)
1328 mesg->complete(mesg->context);
1329}
1330EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1331
1332static int spi_start_queue(struct spi_master *master)
1333{
1334 unsigned long flags;
1335
1336 spin_lock_irqsave(&master->queue_lock, flags);
1337
1338 if (master->running || master->busy) {
1339 spin_unlock_irqrestore(&master->queue_lock, flags);
1340 return -EBUSY;
1341 }
1342
1343 master->running = true;
1344 master->cur_msg = NULL;
1345 spin_unlock_irqrestore(&master->queue_lock, flags);
1346
1347 queue_kthread_work(&master->kworker, &master->pump_messages);
1348
1349 return 0;
1350}
1351
1352static int spi_stop_queue(struct spi_master *master)
1353{
1354 unsigned long flags;
1355 unsigned limit = 500;
1356 int ret = 0;
1357
1358 spin_lock_irqsave(&master->queue_lock, flags);
1359
1360 /*
1361 * This is a bit lame, but is optimized for the common execution path.
1362 * A wait_queue on the master->busy could be used, but then the common
1363 * execution path (pump_messages) would be required to call wake_up or
1364 * friends on every SPI message. Do this instead.
1365 */
1366 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1367 spin_unlock_irqrestore(&master->queue_lock, flags);
f97b26b0 1368 usleep_range(10000, 11000);
ffbbdd21
LW		 1369 spin_lock_irqsave(&master->queue_lock, flags);
1370 }
1371
1372 if (!list_empty(&master->queue) || master->busy)
1373 ret = -EBUSY;
1374 else
1375 master->running = false;
1376
1377 spin_unlock_irqrestore(&master->queue_lock, flags);
1378
1379 if (ret) {
1380 dev_warn(&master->dev,
1381 "could not stop message queue\n");
1382 return ret;
1383 }
1384 return ret;
1385}
1386
1387static int spi_destroy_queue(struct spi_master *master)
1388{
1389 int ret;
1390
1391 ret = spi_stop_queue(master);
1392
1393 /*
1394 * flush_kthread_worker will block until all work is done.
1395 * If the reason that stop_queue timed out is that the work will never
1396 * finish, then it does no good to call flush/stop thread, so
1397 * return anyway.
1398 */
1399 if (ret) {
1400 dev_err(&master->dev, "problem destroying queue\n");
1401 return ret;
1402 }
1403
1404 flush_kthread_worker(&master->kworker);
1405 kthread_stop(master->kworker_task);
1406
1407 return 0;
1408}
1409
0461a414
MB		 1410static int __spi_queued_transfer(struct spi_device *spi,
1411 struct spi_message *msg,
1412 bool need_pump)
ffbbdd21
LW		 1413{
1414 struct spi_master *master = spi->master;
1415 unsigned long flags;
1416
1417 spin_lock_irqsave(&master->queue_lock, flags);
1418
1419 if (!master->running) {
1420 spin_unlock_irqrestore(&master->queue_lock, flags);
1421 return -ESHUTDOWN;
1422 }
1423 msg->actual_length = 0;
1424 msg->status = -EINPROGRESS;
1425
1426 list_add_tail(&msg->queue, &master->queue);
0461a414 1427 if (!master->busy && need_pump)
ffbbdd21
LW		 1428 queue_kthread_work(&master->kworker, &master->pump_messages);
1429
1430 spin_unlock_irqrestore(&master->queue_lock, flags);
1431 return 0;
1432}
1433
0461a414
MB		 1434/**
1435 * spi_queued_transfer - transfer function for queued transfers
1436 * @spi: spi device which is requesting transfer
1437 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1438 *
1439 * Return: zero on success, else a negative error code.
0461a414
MB		 1440 */
1441static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1442{
1443 return __spi_queued_transfer(spi, msg, true);
1444}
1445
ffbbdd21
LW		 1446static int spi_master_initialize_queue(struct spi_master *master)
1447{
1448 int ret;
1449
ffbbdd21 1450 master->transfer = spi_queued_transfer;
b158935f
MB		 1451 if (!master->transfer_one_message)
1452 master->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1453
1454 /* Initialize and start queue */
1455 ret = spi_init_queue(master);
1456 if (ret) {
1457 dev_err(&master->dev, "problem initializing queue\n");
1458 goto err_init_queue;
1459 }
c3676d5c 1460 master->queued = true;
ffbbdd21
LW		 1461 ret = spi_start_queue(master);
1462 if (ret) {
1463 dev_err(&master->dev, "problem starting queue\n");
1464 goto err_start_queue;
1465 }
1466
1467 return 0;
1468
1469err_start_queue:
ffbbdd21 1470 spi_destroy_queue(master);
c3676d5c 1471err_init_queue:
ffbbdd21
LW		 1472 return ret;
1473}
1474
1475/*-------------------------------------------------------------------------*/
1476
7cb94361 1477#if defined(CONFIG_OF)
aff5e3f8
PA		 1478static struct spi_device *
1479of_register_spi_device(struct spi_master *master, struct device_node *nc)
1480{
1481 struct spi_device *spi;
1482 int rc;
1483 u32 value;
1484
1485 /* Alloc an spi_device */
1486 spi = spi_alloc_device(master);
1487 if (!spi) {
1488 dev_err(&master->dev, "spi_device alloc error for %s\n",
1489 nc->full_name);
1490 rc = -ENOMEM;
1491 goto err_out;
1492 }
1493
1494 /* Select device driver */
1495 rc = of_modalias_node(nc, spi->modalias,
1496 sizeof(spi->modalias));
1497 if (rc < 0) {
1498 dev_err(&master->dev, "cannot find modalias for %s\n",
1499 nc->full_name);
1500 goto err_out;
1501 }
1502
1503 /* Device address */
1504 rc = of_property_read_u32(nc, "reg", &value);
1505 if (rc) {
1506 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1507 nc->full_name, rc);
1508 goto err_out;
1509 }
1510 spi->chip_select = value;
1511
1512 /* Mode (clock phase/polarity/etc.) */
1513 if (of_find_property(nc, "spi-cpha", NULL))
1514 spi->mode |= SPI_CPHA;
1515 if (of_find_property(nc, "spi-cpol", NULL))
1516 spi->mode |= SPI_CPOL;
1517 if (of_find_property(nc, "spi-cs-high", NULL))
1518 spi->mode |= SPI_CS_HIGH;
1519 if (of_find_property(nc, "spi-3wire", NULL))
1520 spi->mode |= SPI_3WIRE;
1521 if (of_find_property(nc, "spi-lsb-first", NULL))
1522 spi->mode |= SPI_LSB_FIRST;
1523
1524 /* Device DUAL/QUAD mode */
1525 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1526 switch (value) {
1527 case 1:
1528 break;
1529 case 2:
1530 spi->mode |= SPI_TX_DUAL;
1531 break;
1532 case 4:
1533 spi->mode |= SPI_TX_QUAD;
1534 break;
1535 default:
1536 dev_warn(&master->dev,
1537 "spi-tx-bus-width %d not supported\n",
1538 value);
1539 break;
1540 }
1541 }
1542
1543 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1544 switch (value) {
1545 case 1:
1546 break;
1547 case 2:
1548 spi->mode |= SPI_RX_DUAL;
1549 break;
1550 case 4:
1551 spi->mode |= SPI_RX_QUAD;
1552 break;
1553 default:
1554 dev_warn(&master->dev,
1555 "spi-rx-bus-width %d not supported\n",
1556 value);
1557 break;
1558 }
1559 }
1560
1561 /* Device speed */
1562 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1563 if (rc) {
1564 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1565 nc->full_name, rc);
1566 goto err_out;
1567 }
1568 spi->max_speed_hz = value;
1569
aff5e3f8
PA		 1570 /* Store a pointer to the node in the device structure */
1571 of_node_get(nc);
1572 spi->dev.of_node = nc;
1573
1574 /* Register the new device */
aff5e3f8
PA		 1575 rc = spi_add_device(spi);
1576 if (rc) {
1577 dev_err(&master->dev, "spi_device register error %s\n",
1578 nc->full_name);
1579 goto err_out;
1580 }
1581
1582 return spi;
1583
1584err_out:
1585 spi_dev_put(spi);
1586 return ERR_PTR(rc);
1587}
1588
d57a4282
GL		 1589/**
1590 * of_register_spi_devices() - Register child devices onto the SPI bus
1591 * @master: Pointer to spi_master device
1592 *
1593 * Registers an spi_device for each child node of master node which has a 'reg'
1594 * property.
1595 */
1596static void of_register_spi_devices(struct spi_master *master)
1597{
1598 struct spi_device *spi;
1599 struct device_node *nc;
d57a4282
GL		 1600
1601 if (!master->dev.of_node)
1602 return;
1603
f3b6159e 1604 for_each_available_child_of_node(master->dev.of_node, nc) {
bd6c1644
GU		 1605 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1606 continue;
aff5e3f8
PA		 1607 spi = of_register_spi_device(master, nc);
1608 if (IS_ERR(spi))
1609 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
d57a4282 1610 nc->full_name);
d57a4282
GL		 1611 }
1612}
1613#else
1614static void of_register_spi_devices(struct spi_master *master) { }
1615#endif
1616
64bee4d2
MW		 1617#ifdef CONFIG_ACPI
1618static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1619{
1620 struct spi_device *spi = data;
a0a90718 1621 struct spi_master *master = spi->master;
64bee4d2
MW		 1622
1623 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1624 struct acpi_resource_spi_serialbus *sb;
1625
1626 sb = &ares->data.spi_serial_bus;
1627 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
a0a90718
MW		 1628 /*
1629 * ACPI DeviceSelection numbering is handled by the
1630 * host controller driver in Windows and can vary
1631 * from driver to driver. In Linux we always expect
1632 * 0 .. max - 1 so we need to ask the driver to
1633 * translate between the two schemes.
1634 */
1635 if (master->fw_translate_cs) {
1636 int cs = master->fw_translate_cs(master,
1637 sb->device_selection);
1638 if (cs < 0)
1639 return cs;
1640 spi->chip_select = cs;
1641 } else {
1642 spi->chip_select = sb->device_selection;
1643 }
1644
64bee4d2
MW		 1645 spi->max_speed_hz = sb->connection_speed;
1646
1647 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1648 spi->mode |= SPI_CPHA;
1649 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1650 spi->mode |= SPI_CPOL;
1651 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1652 spi->mode |= SPI_CS_HIGH;
1653 }
1654 } else if (spi->irq < 0) {
1655 struct resource r;
1656
1657 if (acpi_dev_resource_interrupt(ares, 0, &r))
1658 spi->irq = r.start;
1659 }
1660
1661 /* Always tell the ACPI core to skip this resource */
1662 return 1;
1663}
1664
7f24467f
OP		 1665static acpi_status acpi_register_spi_device(struct spi_master *master,
1666 struct acpi_device *adev)
64bee4d2 1667{
64bee4d2 1668 struct list_head resource_list;
64bee4d2
MW		 1669 struct spi_device *spi;
1670 int ret;
1671
7f24467f
OP		 1672 if (acpi_bus_get_status(adev) || !adev->status.present ||
1673 acpi_device_enumerated(adev))
64bee4d2
MW		 1674 return AE_OK;
1675
1676 spi = spi_alloc_device(master);
1677 if (!spi) {
1678 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1679 dev_name(&adev->dev));
1680 return AE_NO_MEMORY;
1681 }
1682
7b199811 1683 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1684 spi->irq = -1;
1685
1686 INIT_LIST_HEAD(&resource_list);
1687 ret = acpi_dev_get_resources(adev, &resource_list,
1688 acpi_spi_add_resource, spi);
1689 acpi_dev_free_resource_list(&resource_list);
1690
1691 if (ret < 0 || !spi->max_speed_hz) {
1692 spi_dev_put(spi);
1693 return AE_OK;
1694 }
1695
33ada67d
CR		 1696 if (spi->irq < 0)
1697 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1698
7f24467f
OP		 1699 acpi_device_set_enumerated(adev);
1700
33cf00e5 1701 adev->power.flags.ignore_parent = true;
cf9eb39c 1702 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
64bee4d2 1703 if (spi_add_device(spi)) {
33cf00e5 1704 adev->power.flags.ignore_parent = false;
64bee4d2
MW		 1705 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1706 dev_name(&adev->dev));
1707 spi_dev_put(spi);
1708 }
1709
1710 return AE_OK;
1711}
1712
7f24467f
OP		 1713static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1714 void *data, void **return_value)
1715{
1716 struct spi_master *master = data;
1717 struct acpi_device *adev;
1718
1719 if (acpi_bus_get_device(handle, &adev))
1720 return AE_OK;
1721
1722 return acpi_register_spi_device(master, adev);
1723}
1724
64bee4d2
MW		 1725static void acpi_register_spi_devices(struct spi_master *master)
1726{
1727 acpi_status status;
1728 acpi_handle handle;
1729
29896178 1730 handle = ACPI_HANDLE(master->dev.parent);
64bee4d2
MW		 1731 if (!handle)
1732 return;
1733
1734 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1735 acpi_spi_add_device, NULL,
1736 master, NULL);
1737 if (ACPI_FAILURE(status))
1738 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1739}
1740#else
1741static inline void acpi_register_spi_devices(struct spi_master *master) {}
1742#endif /* CONFIG_ACPI */
1743
49dce689 1744static void spi_master_release(struct device *dev)
8ae12a0d
DB		 1745{
1746 struct spi_master *master;
1747
49dce689 1748 master = container_of(dev, struct spi_master, dev);
8ae12a0d
DB		 1749 kfree(master);
1750}
1751
1752static struct class spi_master_class = {
1753 .name = "spi_master",
1754 .owner = THIS_MODULE,
49dce689 1755 .dev_release = spi_master_release,
eca2ebc7 1756 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1757};
1758
1759
1760/**
1761 * spi_alloc_master - allocate SPI master controller
1762 * @dev: the controller, possibly using the platform_bus
33e34dc6 1763 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 1764 * memory is in the driver_data field of the returned device,
0c868461 1765 * accessible with spi_master_get_devdata().
33e34dc6 1766 * Context: can sleep
8ae12a0d
DB		 1767 *
1768 * This call is used only by SPI master controller drivers, which are the
1769 * only ones directly touching chip registers. It's how they allocate
ba1a0513 1770 * an spi_master structure, prior to calling spi_register_master().
8ae12a0d 1771 *
97d56dc6 1772 * This must be called from context that can sleep.
8ae12a0d
DB		 1773 *
1774 * The caller is responsible for assigning the bus number and initializing
ba1a0513 1775 * the master's methods before calling spi_register_master(); and (after errors
a394d635 1776 * adding the device) calling spi_master_put() to prevent a memory leak.
97d56dc6
JMC		 1777 *
1778 * Return: the SPI master structure on success, else NULL.
8ae12a0d 1779 */
e9d5a461 1780struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
8ae12a0d
DB		 1781{
1782 struct spi_master *master;
1783
0c868461
DB		 1784 if (!dev)
1785 return NULL;
1786
5fe5f05e 1787 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
8ae12a0d
DB		 1788 if (!master)
1789 return NULL;
1790
49dce689 1791 device_initialize(&master->dev);
1e8a52e1
GL		 1792 master->bus_num = -1;
1793 master->num_chipselect = 1;
49dce689 1794 master->dev.class = &spi_master_class;
157f38f9 1795 master->dev.parent = dev;
d7e2ee25 1796 pm_suspend_ignore_children(&master->dev, true);
0c868461 1797 spi_master_set_devdata(master, &master[1]);
8ae12a0d
DB		 1798
1799 return master;
1800}
1801EXPORT_SYMBOL_GPL(spi_alloc_master);
1802
74317984
JCPV		 1803#ifdef CONFIG_OF
1804static int of_spi_register_master(struct spi_master *master)
1805{
e80beb27 1806 int nb, i, *cs;
74317984
JCPV		 1807 struct device_node *np = master->dev.of_node;
1808
1809 if (!np)
1810 return 0;
1811
1812 nb = of_gpio_named_count(np, "cs-gpios");
5fe5f05e 1813 master->num_chipselect = max_t(int, nb, master->num_chipselect);
74317984 1814
8ec5d84e
AL		 1815 /* Return error only for an incorrectly formed cs-gpios property */
1816 if (nb == 0 || nb == -ENOENT)
74317984 1817 return 0;
8ec5d84e
AL		 1818 else if (nb < 0)
1819 return nb;
74317984
JCPV		 1820
1821 cs = devm_kzalloc(&master->dev,
1822 sizeof(int) * master->num_chipselect,
1823 GFP_KERNEL);
1824 master->cs_gpios = cs;
1825
1826 if (!master->cs_gpios)
1827 return -ENOMEM;
1828
0da83bb1 1829 for (i = 0; i < master->num_chipselect; i++)
446411e1 1830 cs[i] = -ENOENT;
74317984
JCPV		 1831
1832 for (i = 0; i < nb; i++)
1833 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1834
1835 return 0;
1836}
1837#else
1838static int of_spi_register_master(struct spi_master *master)
1839{
1840 return 0;
1841}
1842#endif
1843
8ae12a0d
DB		 1844/**
1845 * spi_register_master - register SPI master controller
1846 * @master: initialized master, originally from spi_alloc_master()
33e34dc6 1847 * Context: can sleep
8ae12a0d
DB		 1848 *
1849 * SPI master controllers connect to their drivers using some non-SPI bus,
1850 * such as the platform bus. The final stage of probe() in that code
1851 * includes calling spi_register_master() to hook up to this SPI bus glue.
1852 *
1853 * SPI controllers use board specific (often SOC specific) bus numbers,
1854 * and board-specific addressing for SPI devices combines those numbers
1855 * with chip select numbers. Since SPI does not directly support dynamic
1856 * device identification, boards need configuration tables telling which
1857 * chip is at which address.
1858 *
1859 * This must be called from context that can sleep. It returns zero on
1860 * success, else a negative error code (dropping the master's refcount).
0c868461
DB		 1861 * After a successful return, the caller is responsible for calling
1862 * spi_unregister_master().
97d56dc6
JMC		 1863 *
1864 * Return: zero on success, else a negative error code.
8ae12a0d 1865 */
e9d5a461 1866int spi_register_master(struct spi_master *master)
8ae12a0d 1867{
e44a45ae 1868 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
49dce689 1869 struct device *dev = master->dev.parent;
2b9603a0 1870 struct boardinfo *bi;
8ae12a0d
DB		 1871 int status = -ENODEV;
1872 int dynamic = 0;
1873
0c868461
DB		 1874 if (!dev)
1875 return -ENODEV;
1876
74317984
JCPV		 1877 status = of_spi_register_master(master);
1878 if (status)
1879 return status;
1880
082c8cb4
DB		 1881 /* even if it's just one always-selected device, there must
1882 * be at least one chipselect
1883 */
1884 if (master->num_chipselect == 0)
1885 return -EINVAL;
1886
bb29785e
GL		 1887 if ((master->bus_num < 0) && master->dev.of_node)
1888 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1889
8ae12a0d 1890 /* convention: dynamically assigned bus IDs count down from the max */
a020ed75 1891 if (master->bus_num < 0) {
082c8cb4
DB		 1892 /* FIXME switch to an IDR based scheme, something like
1893 * I2C now uses, so we can't run out of "dynamic" IDs
1894 */
8ae12a0d 1895 master->bus_num = atomic_dec_return(&dyn_bus_id);
b885244e 1896 dynamic = 1;
8ae12a0d
DB		 1897 }
1898
5424d43e
MB		 1899 INIT_LIST_HEAD(&master->queue);
1900 spin_lock_init(&master->queue_lock);
cf32b71e
ES		 1901 spin_lock_init(&master->bus_lock_spinlock);
1902 mutex_init(&master->bus_lock_mutex);
ef4d96ec 1903 mutex_init(&master->io_mutex);
cf32b71e 1904 master->bus_lock_flag = 0;
b158935f 1905 init_completion(&master->xfer_completion);
6ad45a27
MB		 1906 if (!master->max_dma_len)
1907 master->max_dma_len = INT_MAX;
cf32b71e 1908
8ae12a0d
DB		 1909 /* register the device, then userspace will see it.
1910 * registration fails if the bus ID is in use.
1911 */
35f74fca 1912 dev_set_name(&master->dev, "spi%u", master->bus_num);
49dce689 1913 status = device_add(&master->dev);
b885244e 1914 if (status < 0)
8ae12a0d 1915 goto done;
35f74fca 1916 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
8ae12a0d
DB		 1917 dynamic ? " (dynamic)" : "");
1918
ffbbdd21
LW		 1919 /* If we're using a queued driver, start the queue */
1920 if (master->transfer)
1921 dev_info(dev, "master is unqueued, this is deprecated\n");
1922 else {
1923 status = spi_master_initialize_queue(master);
1924 if (status) {
e93b0724 1925 device_del(&master->dev);
ffbbdd21
LW		 1926 goto done;
1927 }
1928 }
eca2ebc7
MS		 1929 /* add statistics */
1930 spin_lock_init(&master->statistics.lock);
ffbbdd21 1931
2b9603a0
FT		 1932 mutex_lock(&board_lock);
1933 list_add_tail(&master->list, &spi_master_list);
1934 list_for_each_entry(bi, &board_list, list)
1935 spi_match_master_to_boardinfo(master, &bi->board_info);
1936 mutex_unlock(&board_lock);
1937
64bee4d2 1938 /* Register devices from the device tree and ACPI */
12b15e83 1939 of_register_spi_devices(master);
64bee4d2 1940 acpi_register_spi_devices(master);
8ae12a0d
DB		 1941done:
1942 return status;
1943}
1944EXPORT_SYMBOL_GPL(spi_register_master);
1945
666d5b4c
MB		 1946static void devm_spi_unregister(struct device *dev, void *res)
1947{
1948 spi_unregister_master(*(struct spi_master **)res);
1949}
1950
1951/**
1952 * dev_spi_register_master - register managed SPI master controller
1953 * @dev: device managing SPI master
1954 * @master: initialized master, originally from spi_alloc_master()
1955 * Context: can sleep
1956 *
1957 * Register a SPI device as with spi_register_master() which will
1958 * automatically be unregister
97d56dc6
JMC		 1959 *
1960 * Return: zero on success, else a negative error code.
666d5b4c
MB		 1961 */
1962int devm_spi_register_master(struct device *dev, struct spi_master *master)
1963{
1964 struct spi_master **ptr;
1965 int ret;
1966
1967 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1968 if (!ptr)
1969 return -ENOMEM;
1970
1971 ret = spi_register_master(master);
4b92894e 1972 if (!ret) {
666d5b4c
MB		 1973 *ptr = master;
1974 devres_add(dev, ptr);
1975 } else {
1976 devres_free(ptr);
1977 }
1978
1979 return ret;
1980}
1981EXPORT_SYMBOL_GPL(devm_spi_register_master);
1982
34860089 1983static int __unregister(struct device *dev, void *null)
8ae12a0d 1984{
34860089 1985 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 1986 return 0;
1987}
1988
1989/**
1990 * spi_unregister_master - unregister SPI master controller
1991 * @master: the master being unregistered
33e34dc6 1992 * Context: can sleep
8ae12a0d
DB		 1993 *
1994 * This call is used only by SPI master controller drivers, which are the
1995 * only ones directly touching chip registers.
1996 *
1997 * This must be called from context that can sleep.
1998 */
1999void spi_unregister_master(struct spi_master *master)
2000{
89fc9a1a
JG		 2001 int dummy;
2002
ffbbdd21
LW		 2003 if (master->queued) {
2004 if (spi_destroy_queue(master))
2005 dev_err(&master->dev, "queue remove failed\n");
2006 }
2007
2b9603a0
FT		 2008 mutex_lock(&board_lock);
2009 list_del(&master->list);
2010 mutex_unlock(&board_lock);
2011
97dbf37d 2012 dummy = device_for_each_child(&master->dev, NULL, __unregister);
49dce689 2013 device_unregister(&master->dev);
8ae12a0d
DB		 2014}
2015EXPORT_SYMBOL_GPL(spi_unregister_master);
2016
ffbbdd21
LW		 2017int spi_master_suspend(struct spi_master *master)
2018{
2019 int ret;
2020
2021 /* Basically no-ops for non-queued masters */
2022 if (!master->queued)
2023 return 0;
2024
2025 ret = spi_stop_queue(master);
2026 if (ret)
2027 dev_err(&master->dev, "queue stop failed\n");
2028
2029 return ret;
2030}
2031EXPORT_SYMBOL_GPL(spi_master_suspend);
2032
2033int spi_master_resume(struct spi_master *master)
2034{
2035 int ret;
2036
2037 if (!master->queued)
2038 return 0;
2039
2040 ret = spi_start_queue(master);
2041 if (ret)
2042 dev_err(&master->dev, "queue restart failed\n");
2043
2044 return ret;
2045}
2046EXPORT_SYMBOL_GPL(spi_master_resume);
2047
9f3b795a 2048static int __spi_master_match(struct device *dev, const void *data)
5ed2c832
DY		 2049{
2050 struct spi_master *m;
9f3b795a 2051 const u16 *bus_num = data;
5ed2c832
DY		 2052
2053 m = container_of(dev, struct spi_master, dev);
2054 return m->bus_num == *bus_num;
2055}
2056
8ae12a0d
DB		 2057/**
2058 * spi_busnum_to_master - look up master associated with bus_num
2059 * @bus_num: the master's bus number
33e34dc6 2060 * Context: can sleep
8ae12a0d
DB		 2061 *
2062 * This call may be used with devices that are registered after
2063 * arch init time. It returns a refcounted pointer to the relevant
2064 * spi_master (which the caller must release), or NULL if there is
2065 * no such master registered.
97d56dc6
JMC		 2066 *
2067 * Return: the SPI master structure on success, else NULL.
8ae12a0d
DB		 2068 */
2069struct spi_master *spi_busnum_to_master(u16 bus_num)
2070{
49dce689 2071 struct device *dev;
1e9a51dc 2072 struct spi_master *master = NULL;
5ed2c832 2073
695794ae 2074 dev = class_find_device(&spi_master_class, NULL, &bus_num,
5ed2c832
DY		 2075 __spi_master_match);
2076 if (dev)
2077 master = container_of(dev, struct spi_master, dev);
2078 /* reference got in class_find_device */
1e9a51dc 2079 return master;
8ae12a0d
DB		 2080}
2081EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2082
d780c371
MS		 2083/*-------------------------------------------------------------------------*/
2084
2085/* Core methods for SPI resource management */
2086
2087/**
2088 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2089 * during the processing of a spi_message while using
2090 * spi_transfer_one
2091 * @spi: the spi device for which we allocate memory
2092 * @release: the release code to execute for this resource
2093 * @size: size to alloc and return
2094 * @gfp: GFP allocation flags
2095 *
2096 * Return: the pointer to the allocated data
2097 *
2098 * This may get enhanced in the future to allocate from a memory pool
2099 * of the @spi_device or @spi_master to avoid repeated allocations.
2100 */
2101void *spi_res_alloc(struct spi_device *spi,
2102 spi_res_release_t release,
2103 size_t size, gfp_t gfp)
2104{
2105 struct spi_res *sres;
2106
2107 sres = kzalloc(sizeof(*sres) + size, gfp);
2108 if (!sres)
2109 return NULL;
2110
2111 INIT_LIST_HEAD(&sres->entry);
2112 sres->release = release;
2113
2114 return sres->data;
2115}
2116EXPORT_SYMBOL_GPL(spi_res_alloc);
2117
2118/**
2119 * spi_res_free - free an spi resource
2120 * @res: pointer to the custom data of a resource
2121 *
2122 */
2123void spi_res_free(void *res)
2124{
2125 struct spi_res *sres = container_of(res, struct spi_res, data);
2126
2127 if (!res)
2128 return;
2129
2130 WARN_ON(!list_empty(&sres->entry));
2131 kfree(sres);
2132}
2133EXPORT_SYMBOL_GPL(spi_res_free);
2134
2135/**
2136 * spi_res_add - add a spi_res to the spi_message
2137 * @message: the spi message
2138 * @res: the spi_resource
2139 */
2140void spi_res_add(struct spi_message *message, void *res)
2141{
2142 struct spi_res *sres = container_of(res, struct spi_res, data);
2143
2144 WARN_ON(!list_empty(&sres->entry));
2145 list_add_tail(&sres->entry, &message->resources);
2146}
2147EXPORT_SYMBOL_GPL(spi_res_add);
2148
2149/**
2150 * spi_res_release - release all spi resources for this message
2151 * @master: the @spi_master
2152 * @message: the @spi_message
2153 */
2154void spi_res_release(struct spi_master *master,
2155 struct spi_message *message)
2156{
2157 struct spi_res *res;
2158
2159 while (!list_empty(&message->resources)) {
2160 res = list_last_entry(&message->resources,
2161 struct spi_res, entry);
2162
2163 if (res->release)
2164 res->release(master, message, res->data);
2165
2166 list_del(&res->entry);
2167
2168 kfree(res);
2169 }
2170}
2171EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2172
2173/*-------------------------------------------------------------------------*/
2174
523baf5a
MS		 2175/* Core methods for spi_message alterations */
2176
2177static void __spi_replace_transfers_release(struct spi_master *master,
2178 struct spi_message *msg,
2179 void *res)
2180{
2181 struct spi_replaced_transfers *rxfer = res;
2182 size_t i;
2183
2184 /* call extra callback if requested */
2185 if (rxfer->release)
2186 rxfer->release(master, msg, res);
2187
2188 /* insert replaced transfers back into the message */
2189 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2190
2191 /* remove the formerly inserted entries */
2192 for (i = 0; i < rxfer->inserted; i++)
2193 list_del(&rxfer->inserted_transfers[i].transfer_list);
2194}
2195
2196/**
2197 * spi_replace_transfers - replace transfers with several transfers
2198 * and register change with spi_message.resources
2199 * @msg: the spi_message we work upon
2200 * @xfer_first: the first spi_transfer we want to replace
2201 * @remove: number of transfers to remove
2202 * @insert: the number of transfers we want to insert instead
2203 * @release: extra release code necessary in some circumstances
2204 * @extradatasize: extra data to allocate (with alignment guarantees
2205 * of struct @spi_transfer)
05885397 2206 * @gfp: gfp flags
523baf5a
MS		 2207 *
2208 * Returns: pointer to @spi_replaced_transfers,
2209 * PTR_ERR(...) in case of errors.
2210 */
2211struct spi_replaced_transfers *spi_replace_transfers(
2212 struct spi_message *msg,
2213 struct spi_transfer *xfer_first,
2214 size_t remove,
2215 size_t insert,
2216 spi_replaced_release_t release,
2217 size_t extradatasize,
2218 gfp_t gfp)
2219{
2220 struct spi_replaced_transfers *rxfer;
2221 struct spi_transfer *xfer;
2222 size_t i;
2223
2224 /* allocate the structure using spi_res */
2225 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2226 insert * sizeof(struct spi_transfer)
2227 + sizeof(struct spi_replaced_transfers)
2228 + extradatasize,
2229 gfp);
2230 if (!rxfer)
2231 return ERR_PTR(-ENOMEM);
2232
2233 /* the release code to invoke before running the generic release */
2234 rxfer->release = release;
2235
2236 /* assign extradata */
2237 if (extradatasize)
2238 rxfer->extradata =
2239 &rxfer->inserted_transfers[insert];
2240
2241 /* init the replaced_transfers list */
2242 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2243
2244 /* assign the list_entry after which we should reinsert
2245 * the @replaced_transfers - it may be spi_message.messages!
2246 */
2247 rxfer->replaced_after = xfer_first->transfer_list.prev;
2248
2249 /* remove the requested number of transfers */
2250 for (i = 0; i < remove; i++) {
2251 /* if the entry after replaced_after it is msg->transfers
2252 * then we have been requested to remove more transfers
2253 * than are in the list
2254 */
2255 if (rxfer->replaced_after->next == &msg->transfers) {
2256 dev_err(&msg->spi->dev,
2257 "requested to remove more spi_transfers than are available\n");
2258 /* insert replaced transfers back into the message */
2259 list_splice(&rxfer->replaced_transfers,
2260 rxfer->replaced_after);
2261
2262 /* free the spi_replace_transfer structure */
2263 spi_res_free(rxfer);
2264
2265 /* and return with an error */
2266 return ERR_PTR(-EINVAL);
2267 }
2268
2269 /* remove the entry after replaced_after from list of
2270 * transfers and add it to list of replaced_transfers
2271 */
2272 list_move_tail(rxfer->replaced_after->next,
2273 &rxfer->replaced_transfers);
2274 }
2275
2276 /* create copy of the given xfer with identical settings
2277 * based on the first transfer to get removed
2278 */
2279 for (i = 0; i < insert; i++) {
2280 /* we need to run in reverse order */
2281 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2282
2283 /* copy all spi_transfer data */
2284 memcpy(xfer, xfer_first, sizeof(*xfer));
2285
2286 /* add to list */
2287 list_add(&xfer->transfer_list, rxfer->replaced_after);
2288
2289 /* clear cs_change and delay_usecs for all but the last */
2290 if (i) {
2291 xfer->cs_change = false;
2292 xfer->delay_usecs = 0;
2293 }
2294 }
2295
2296 /* set up inserted */
2297 rxfer->inserted = insert;
2298
2299 /* and register it with spi_res/spi_message */
2300 spi_res_add(msg, rxfer);
2301
2302 return rxfer;
2303}
2304EXPORT_SYMBOL_GPL(spi_replace_transfers);
2305
08933418
FE		 2306static int __spi_split_transfer_maxsize(struct spi_master *master,
2307 struct spi_message *msg,
2308 struct spi_transfer **xferp,
2309 size_t maxsize,
2310 gfp_t gfp)
d9f12122
MS		 2311{
2312 struct spi_transfer *xfer = *xferp, *xfers;
2313 struct spi_replaced_transfers *srt;
2314 size_t offset;
2315 size_t count, i;
2316
2317 /* warn once about this fact that we are splitting a transfer */
2318 dev_warn_once(&msg->spi->dev,
7d62f51e 2319 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
d9f12122
MS		 2320 xfer->len, maxsize);
2321
2322 /* calculate how many we have to replace */
2323 count = DIV_ROUND_UP(xfer->len, maxsize);
2324
2325 /* create replacement */
2326 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2327 if (IS_ERR(srt))
2328 return PTR_ERR(srt);
d9f12122
MS		 2329 xfers = srt->inserted_transfers;
2330
2331 /* now handle each of those newly inserted spi_transfers
2332 * note that the replacements spi_transfers all are preset
2333 * to the same values as *xferp, so tx_buf, rx_buf and len
2334 * are all identical (as well as most others)
2335 * so we just have to fix up len and the pointers.
2336 *
2337 * this also includes support for the depreciated
2338 * spi_message.is_dma_mapped interface
2339 */
2340
2341 /* the first transfer just needs the length modified, so we
2342 * run it outside the loop
2343 */
c8dab77a 2344 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
d9f12122
MS		 2345
2346 /* all the others need rx_buf/tx_buf also set */
2347 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2348 /* update rx_buf, tx_buf and dma */
2349 if (xfers[i].rx_buf)
2350 xfers[i].rx_buf += offset;
2351 if (xfers[i].rx_dma)
2352 xfers[i].rx_dma += offset;
2353 if (xfers[i].tx_buf)
2354 xfers[i].tx_buf += offset;
2355 if (xfers[i].tx_dma)
2356 xfers[i].tx_dma += offset;
2357
2358 /* update length */
2359 xfers[i].len = min(maxsize, xfers[i].len - offset);
2360 }
2361
2362 /* we set up xferp to the last entry we have inserted,
2363 * so that we skip those already split transfers
2364 */
2365 *xferp = &xfers[count - 1];
2366
2367 /* increment statistics counters */
2368 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2369 transfers_split_maxsize);
2370 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2371 transfers_split_maxsize);
2372
2373 return 0;
2374}
2375
2376/**
2377 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2378 * when an individual transfer exceeds a
2379 * certain size
2380 * @master: the @spi_master for this transfer
3700ce95
MI		 2381 * @msg: the @spi_message to transform
2382 * @maxsize: the maximum when to apply this
10f11a22 2383 * @gfp: GFP allocation flags
d9f12122
MS		 2384 *
2385 * Return: status of transformation
2386 */
2387int spi_split_transfers_maxsize(struct spi_master *master,
2388 struct spi_message *msg,
2389 size_t maxsize,
2390 gfp_t gfp)
2391{
2392 struct spi_transfer *xfer;
2393 int ret;
2394
2395 /* iterate over the transfer_list,
2396 * but note that xfer is advanced to the last transfer inserted
2397 * to avoid checking sizes again unnecessarily (also xfer does
2398 * potentiall belong to a different list by the time the
2399 * replacement has happened
2400 */
2401 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2402 if (xfer->len > maxsize) {
2403 ret = __spi_split_transfer_maxsize(
2404 master, msg, &xfer, maxsize, gfp);
2405 if (ret)
2406 return ret;
2407 }
2408 }
2409
2410 return 0;
2411}
2412EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
8ae12a0d
DB		 2413
2414/*-------------------------------------------------------------------------*/
2415
7d077197
DB		 2416/* Core methods for SPI master protocol drivers. Some of the
2417 * other core methods are currently defined as inline functions.
2418 */
2419
63ab645f
SB		 2420static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2421{
2422 if (master->bits_per_word_mask) {
2423 /* Only 32 bits fit in the mask */
2424 if (bits_per_word > 32)
2425 return -EINVAL;
2426 if (!(master->bits_per_word_mask &
2427 SPI_BPW_MASK(bits_per_word)))
2428 return -EINVAL;
2429 }
2430
2431 return 0;
2432}
2433
7d077197
DB		 2434/**
2435 * spi_setup - setup SPI mode and clock rate
2436 * @spi: the device whose settings are being modified
2437 * Context: can sleep, and no requests are queued to the device
2438 *
2439 * SPI protocol drivers may need to update the transfer mode if the
2440 * device doesn't work with its default. They may likewise need
2441 * to update clock rates or word sizes from initial values. This function
2442 * changes those settings, and must be called from a context that can sleep.
2443 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2444 * effect the next time the device is selected and data is transferred to
2445 * or from it. When this function returns, the spi device is deselected.
2446 *
2447 * Note that this call will fail if the protocol driver specifies an option
2448 * that the underlying controller or its driver does not support. For
2449 * example, not all hardware supports wire transfers using nine bit words,
2450 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2451 *
2452 * Return: zero on success, else a negative error code.
7d077197
DB		 2453 */
2454int spi_setup(struct spi_device *spi)
2455{
83596fbe 2456 unsigned bad_bits, ugly_bits;
5ab8d262 2457 int status;
7d077197 2458
f477b7fb 2459 /* check mode to prevent that DUAL and QUAD set at the same time
2460 */
2461 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2462 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2463 dev_err(&spi->dev,
2464 "setup: can not select dual and quad at the same time\n");
2465 return -EINVAL;
2466 }
2467 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2468 */
2469 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2470 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2471 return -EINVAL;
e7db06b5
DB		 2472 /* help drivers fail *cleanly* when they need options
2473 * that aren't supported with their current master
2474 */
2475 bad_bits = spi->mode & ~spi->master->mode_bits;
83596fbe
GU		 2476 ugly_bits = bad_bits &
2477 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2478 if (ugly_bits) {
2479 dev_warn(&spi->dev,
2480 "setup: ignoring unsupported mode bits %x\n",
2481 ugly_bits);
2482 spi->mode &= ~ugly_bits;
2483 bad_bits &= ~ugly_bits;
2484 }
e7db06b5 2485 if (bad_bits) {
eb288a1f 2486 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2487 bad_bits);
2488 return -EINVAL;
2489 }
2490
7d077197
DB		 2491 if (!spi->bits_per_word)
2492 spi->bits_per_word = 8;
2493
5ab8d262
AS		 2494 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2495 if (status)
2496 return status;
63ab645f 2497
052eb2d4
AL		 2498 if (!spi->max_speed_hz)
2499 spi->max_speed_hz = spi->master->max_speed_hz;
2500
caae070c
LD		 2501 if (spi->master->setup)
2502 status = spi->master->setup(spi);
7d077197 2503
abeedb01
FCJ		 2504 spi_set_cs(spi, false);
2505
5fe5f05e 2506 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2507 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2508 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2509 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2510 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2511 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2512 spi->bits_per_word, spi->max_speed_hz,
2513 status);
2514
2515 return status;
2516}
2517EXPORT_SYMBOL_GPL(spi_setup);
2518
90808738 2519static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2520{
2521 struct spi_master *master = spi->master;
e6811d1d 2522 struct spi_transfer *xfer;
6ea31293 2523 int w_size;
cf32b71e 2524
24a0013a
MB		 2525 if (list_empty(&message->transfers))
2526 return -EINVAL;
24a0013a 2527
cf32b71e
ES		 2528 /* Half-duplex links include original MicroWire, and ones with
2529 * only one data pin like SPI_3WIRE (switches direction) or where
2530 * either MOSI or MISO is missing. They can also be caused by
2531 * software limitations.
2532 */
2533 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2534 || (spi->mode & SPI_3WIRE)) {
cf32b71e
ES		 2535 unsigned flags = master->flags;
2536
2537 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2538 if (xfer->rx_buf && xfer->tx_buf)
2539 return -EINVAL;
2540 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2541 return -EINVAL;
2542 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2543 return -EINVAL;
2544 }
2545 }
2546
e6811d1d 2547 /**
059b8ffe
LD		 2548 * Set transfer bits_per_word and max speed as spi device default if
2549 * it is not set for this transfer.
f477b7fb 2550 * Set transfer tx_nbits and rx_nbits as single transfer default
2551 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2552 */
77e80588 2553 message->frame_length = 0;
e6811d1d 2554 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2555 message->frame_length += xfer->len;
e6811d1d
LD		 2556 if (!xfer->bits_per_word)
2557 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2558
2559 if (!xfer->speed_hz)
059b8ffe 2560 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3
MB		 2561 if (!xfer->speed_hz)
2562 xfer->speed_hz = master->max_speed_hz;
a6f87fad
AL		 2563
2564 if (master->max_speed_hz &&
2565 xfer->speed_hz > master->max_speed_hz)
2566 xfer->speed_hz = master->max_speed_hz;
56ede94a 2567
63ab645f
SB		 2568 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2569 return -EINVAL;
a2fd4f9f 2570
4d94bd21
II		 2571 /*
2572 * SPI transfer length should be multiple of SPI word size
2573 * where SPI word size should be power-of-two multiple
2574 */
2575 if (xfer->bits_per_word <= 8)
2576 w_size = 1;
2577 else if (xfer->bits_per_word <= 16)
2578 w_size = 2;
2579 else
2580 w_size = 4;
2581
4d94bd21 2582 /* No partial transfers accepted */
6ea31293 2583 if (xfer->len % w_size)
4d94bd21
II		 2584 return -EINVAL;
2585
a2fd4f9f
MB		 2586 if (xfer->speed_hz && master->min_speed_hz &&
2587 xfer->speed_hz < master->min_speed_hz)
2588 return -EINVAL;
f477b7fb 2589
2590 if (xfer->tx_buf && !xfer->tx_nbits)
2591 xfer->tx_nbits = SPI_NBITS_SINGLE;
2592 if (xfer->rx_buf && !xfer->rx_nbits)
2593 xfer->rx_nbits = SPI_NBITS_SINGLE;
2594 /* check transfer tx/rx_nbits:
1afd9989
GU		 2595 * 1. check the value matches one of single, dual and quad
2596 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 2597 */
db90a441
SP		 2598 if (xfer->tx_buf) {
2599 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2600 xfer->tx_nbits != SPI_NBITS_DUAL &&
2601 xfer->tx_nbits != SPI_NBITS_QUAD)
2602 return -EINVAL;
2603 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2604 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2605 return -EINVAL;
2606 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2607 !(spi->mode & SPI_TX_QUAD))
2608 return -EINVAL;
db90a441 2609 }
f477b7fb 2610 /* check transfer rx_nbits */
db90a441
SP		 2611 if (xfer->rx_buf) {
2612 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2613 xfer->rx_nbits != SPI_NBITS_DUAL &&
2614 xfer->rx_nbits != SPI_NBITS_QUAD)
2615 return -EINVAL;
2616 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2617 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2618 return -EINVAL;
2619 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2620 !(spi->mode & SPI_RX_QUAD))
2621 return -EINVAL;
db90a441 2622 }
e6811d1d
LD		 2623 }
2624
cf32b71e 2625 message->status = -EINPROGRESS;
90808738
MB		 2626
2627 return 0;
2628}
2629
2630static int __spi_async(struct spi_device *spi, struct spi_message *message)
2631{
2632 struct spi_master *master = spi->master;
2633
2634 message->spi = spi;
2635
eca2ebc7
MS		 2636 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2637 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2638
90808738
MB		 2639 trace_spi_message_submit(message);
2640
cf32b71e
ES		 2641 return master->transfer(spi, message);
2642}
2643
568d0697
DB		 2644/**
2645 * spi_async - asynchronous SPI transfer
2646 * @spi: device with which data will be exchanged
2647 * @message: describes the data transfers, including completion callback
2648 * Context: any (irqs may be blocked, etc)
2649 *
2650 * This call may be used in_irq and other contexts which can't sleep,
2651 * as well as from task contexts which can sleep.
2652 *
2653 * The completion callback is invoked in a context which can't sleep.
2654 * Before that invocation, the value of message->status is undefined.
2655 * When the callback is issued, message->status holds either zero (to
2656 * indicate complete success) or a negative error code. After that
2657 * callback returns, the driver which issued the transfer request may
2658 * deallocate the associated memory; it's no longer in use by any SPI
2659 * core or controller driver code.
2660 *
2661 * Note that although all messages to a spi_device are handled in
2662 * FIFO order, messages may go to different devices in other orders.
2663 * Some device might be higher priority, or have various "hard" access
2664 * time requirements, for example.
2665 *
2666 * On detection of any fault during the transfer, processing of
2667 * the entire message is aborted, and the device is deselected.
2668 * Until returning from the associated message completion callback,
2669 * no other spi_message queued to that device will be processed.
2670 * (This rule applies equally to all the synchronous transfer calls,
2671 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2672 *
2673 * Return: zero on success, else a negative error code.
568d0697
DB		 2674 */
2675int spi_async(struct spi_device *spi, struct spi_message *message)
2676{
2677 struct spi_master *master = spi->master;
cf32b71e
ES		 2678 int ret;
2679 unsigned long flags;
568d0697 2680
90808738
MB		 2681 ret = __spi_validate(spi, message);
2682 if (ret != 0)
2683 return ret;
2684
cf32b71e 2685 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
568d0697 2686
cf32b71e
ES		 2687 if (master->bus_lock_flag)
2688 ret = -EBUSY;
2689 else
2690 ret = __spi_async(spi, message);
568d0697 2691
cf32b71e
ES		 2692 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2693
2694 return ret;
568d0697
DB		 2695}
2696EXPORT_SYMBOL_GPL(spi_async);
2697
cf32b71e
ES		 2698/**
2699 * spi_async_locked - version of spi_async with exclusive bus usage
2700 * @spi: device with which data will be exchanged
2701 * @message: describes the data transfers, including completion callback
2702 * Context: any (irqs may be blocked, etc)
2703 *
2704 * This call may be used in_irq and other contexts which can't sleep,
2705 * as well as from task contexts which can sleep.
2706 *
2707 * The completion callback is invoked in a context which can't sleep.
2708 * Before that invocation, the value of message->status is undefined.
2709 * When the callback is issued, message->status holds either zero (to
2710 * indicate complete success) or a negative error code. After that
2711 * callback returns, the driver which issued the transfer request may
2712 * deallocate the associated memory; it's no longer in use by any SPI
2713 * core or controller driver code.
2714 *
2715 * Note that although all messages to a spi_device are handled in
2716 * FIFO order, messages may go to different devices in other orders.
2717 * Some device might be higher priority, or have various "hard" access
2718 * time requirements, for example.
2719 *
2720 * On detection of any fault during the transfer, processing of
2721 * the entire message is aborted, and the device is deselected.
2722 * Until returning from the associated message completion callback,
2723 * no other spi_message queued to that device will be processed.
2724 * (This rule applies equally to all the synchronous transfer calls,
2725 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2726 *
2727 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2728 */
2729int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2730{
2731 struct spi_master *master = spi->master;
2732 int ret;
2733 unsigned long flags;
2734
90808738
MB		 2735 ret = __spi_validate(spi, message);
2736 if (ret != 0)
2737 return ret;
2738
cf32b71e
ES		 2739 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2740
2741 ret = __spi_async(spi, message);
2742
2743 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2744
2745 return ret;
2746
2747}
2748EXPORT_SYMBOL_GPL(spi_async_locked);
2749
7d077197 2750
556351f1
V		 2751int spi_flash_read(struct spi_device *spi,
2752 struct spi_flash_read_message *msg)
2753
2754{
2755 struct spi_master *master = spi->master;
f4502dd1 2756 struct device *rx_dev = NULL;
556351f1
V		 2757 int ret;
2758
2759 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2760 msg->addr_nbits == SPI_NBITS_DUAL) &&
2761 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2762 return -EINVAL;
2763 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2764 msg->addr_nbits == SPI_NBITS_QUAD) &&
2765 !(spi->mode & SPI_TX_QUAD))
2766 return -EINVAL;
2767 if (msg->data_nbits == SPI_NBITS_DUAL &&
2768 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2769 return -EINVAL;
2770 if (msg->data_nbits == SPI_NBITS_QUAD &&
2771 !(spi->mode & SPI_RX_QUAD))
2772 return -EINVAL;
2773
2774 if (master->auto_runtime_pm) {
2775 ret = pm_runtime_get_sync(master->dev.parent);
2776 if (ret < 0) {
2777 dev_err(&master->dev, "Failed to power device: %d\n",
2778 ret);
2779 return ret;
2780 }
2781 }
f4502dd1 2782
556351f1 2783 mutex_lock(&master->bus_lock_mutex);
ef4d96ec 2784 mutex_lock(&master->io_mutex);
f4502dd1
V		 2785 if (master->dma_rx) {
2786 rx_dev = master->dma_rx->device->dev;
2787 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2788 msg->buf, msg->len,
2789 DMA_FROM_DEVICE);
2790 if (!ret)
2791 msg->cur_msg_mapped = true;
2792 }
556351f1 2793 ret = master->spi_flash_read(spi, msg);
f4502dd1
V		 2794 if (msg->cur_msg_mapped)
2795 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2796 DMA_FROM_DEVICE);
ef4d96ec 2797 mutex_unlock(&master->io_mutex);
556351f1 2798 mutex_unlock(&master->bus_lock_mutex);
f4502dd1 2799
556351f1
V		 2800 if (master->auto_runtime_pm)
2801 pm_runtime_put(master->dev.parent);
2802
2803 return ret;
2804}
2805EXPORT_SYMBOL_GPL(spi_flash_read);
2806
7d077197
DB		 2807/*-------------------------------------------------------------------------*/
2808
2809/* Utility methods for SPI master protocol drivers, layered on
2810 * top of the core. Some other utility methods are defined as
2811 * inline functions.
2812 */
2813
5d870c8e
AM		 2814static void spi_complete(void *arg)
2815{
2816 complete(arg);
2817}
2818
ef4d96ec 2819static int __spi_sync(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2820{
2821 DECLARE_COMPLETION_ONSTACK(done);
2822 int status;
2823 struct spi_master *master = spi->master;
0461a414
MB		 2824 unsigned long flags;
2825
2826 status = __spi_validate(spi, message);
2827 if (status != 0)
2828 return status;
cf32b71e
ES		 2829
2830 message->complete = spi_complete;
2831 message->context = &done;
0461a414 2832 message->spi = spi;
cf32b71e 2833
eca2ebc7
MS		 2834 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2835 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2836
0461a414
MB		 2837 /* If we're not using the legacy transfer method then we will
2838 * try to transfer in the calling context so special case.
2839 * This code would be less tricky if we could remove the
2840 * support for driver implemented message queues.
2841 */
2842 if (master->transfer == spi_queued_transfer) {
2843 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2844
2845 trace_spi_message_submit(message);
2846
2847 status = __spi_queued_transfer(spi, message, false);
2848
2849 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2850 } else {
2851 status = spi_async_locked(spi, message);
2852 }
cf32b71e 2853
cf32b71e 2854 if (status == 0) {
0461a414
MB		 2855 /* Push out the messages in the calling context if we
2856 * can.
2857 */
eca2ebc7
MS		 2858 if (master->transfer == spi_queued_transfer) {
2859 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2860 spi_sync_immediate);
2861 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2862 spi_sync_immediate);
ef4d96ec 2863 __spi_pump_messages(master, false);
eca2ebc7 2864 }
0461a414 2865
cf32b71e
ES		 2866 wait_for_completion(&done);
2867 status = message->status;
2868 }
2869 message->context = NULL;
2870 return status;
2871}
2872
8ae12a0d
DB		 2873/**
2874 * spi_sync - blocking/synchronous SPI data transfers
2875 * @spi: device with which data will be exchanged
2876 * @message: describes the data transfers
33e34dc6 2877 * Context: can sleep
8ae12a0d
DB		 2878 *
2879 * This call may only be used from a context that may sleep. The sleep
2880 * is non-interruptible, and has no timeout. Low-overhead controller
2881 * drivers may DMA directly into and out of the message buffers.
2882 *
2883 * Note that the SPI device's chip select is active during the message,
2884 * and then is normally disabled between messages. Drivers for some
2885 * frequently-used devices may want to minimize costs of selecting a chip,
2886 * by leaving it selected in anticipation that the next message will go
2887 * to the same chip. (That may increase power usage.)
2888 *
0c868461
DB		 2889 * Also, the caller is guaranteeing that the memory associated with the
2890 * message will not be freed before this call returns.
2891 *
97d56dc6 2892 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2893 */
2894int spi_sync(struct spi_device *spi, struct spi_message *message)
2895{
ef4d96ec
MB		 2896 int ret;
2897
2898 mutex_lock(&spi->master->bus_lock_mutex);
2899 ret = __spi_sync(spi, message);
2900 mutex_unlock(&spi->master->bus_lock_mutex);
2901
2902 return ret;
8ae12a0d
DB		 2903}
2904EXPORT_SYMBOL_GPL(spi_sync);
2905
cf32b71e
ES		 2906/**
2907 * spi_sync_locked - version of spi_sync with exclusive bus usage
2908 * @spi: device with which data will be exchanged
2909 * @message: describes the data transfers
2910 * Context: can sleep
2911 *
2912 * This call may only be used from a context that may sleep. The sleep
2913 * is non-interruptible, and has no timeout. Low-overhead controller
2914 * drivers may DMA directly into and out of the message buffers.
2915 *
2916 * This call should be used by drivers that require exclusive access to the
25985edc 2917 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 2918 * be released by a spi_bus_unlock call when the exclusive access is over.
2919 *
97d56dc6 2920 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2921 */
2922int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2923{
ef4d96ec 2924 return __spi_sync(spi, message);
cf32b71e
ES		 2925}
2926EXPORT_SYMBOL_GPL(spi_sync_locked);
2927
2928/**
2929 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2930 * @master: SPI bus master that should be locked for exclusive bus access
2931 * Context: can sleep
2932 *
2933 * This call may only be used from a context that may sleep. The sleep
2934 * is non-interruptible, and has no timeout.
2935 *
2936 * This call should be used by drivers that require exclusive access to the
2937 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2938 * exclusive access is over. Data transfer must be done by spi_sync_locked
2939 * and spi_async_locked calls when the SPI bus lock is held.
2940 *
97d56dc6 2941 * Return: always zero.
cf32b71e
ES		 2942 */
2943int spi_bus_lock(struct spi_master *master)
2944{
2945 unsigned long flags;
2946
2947 mutex_lock(&master->bus_lock_mutex);
2948
2949 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2950 master->bus_lock_flag = 1;
2951 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2952
2953 /* mutex remains locked until spi_bus_unlock is called */
2954
2955 return 0;
2956}
2957EXPORT_SYMBOL_GPL(spi_bus_lock);
2958
2959/**
2960 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2961 * @master: SPI bus master that was locked for exclusive bus access
2962 * Context: can sleep
2963 *
2964 * This call may only be used from a context that may sleep. The sleep
2965 * is non-interruptible, and has no timeout.
2966 *
2967 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2968 * call.
2969 *
97d56dc6 2970 * Return: always zero.
cf32b71e
ES		 2971 */
2972int spi_bus_unlock(struct spi_master *master)
2973{
2974 master->bus_lock_flag = 0;
2975
2976 mutex_unlock(&master->bus_lock_mutex);
2977
2978 return 0;
2979}
2980EXPORT_SYMBOL_GPL(spi_bus_unlock);
2981
a9948b61 2982/* portable code must never pass more than 32 bytes */
5fe5f05e 2983#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 2984
2985static u8 *buf;
2986
2987/**
2988 * spi_write_then_read - SPI synchronous write followed by read
2989 * @spi: device with which data will be exchanged
2990 * @txbuf: data to be written (need not be dma-safe)
2991 * @n_tx: size of txbuf, in bytes
27570497
JP		 2992 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2993 * @n_rx: size of rxbuf, in bytes
33e34dc6 2994 * Context: can sleep
8ae12a0d
DB		 2995 *
2996 * This performs a half duplex MicroWire style transaction with the
2997 * device, sending txbuf and then reading rxbuf. The return value
2998 * is zero for success, else a negative errno status code.
b885244e 2999 * This call may only be used from a context that may sleep.
8ae12a0d 3000 *
0c868461 3001 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 3002 * portable code should never use this for more than 32 bytes.
3003 * Performance-sensitive or bulk transfer code should instead use
0c868461 3004 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 3005 *
3006 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 3007 */
3008int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 3009 const void *txbuf, unsigned n_tx,
3010 void *rxbuf, unsigned n_rx)
8ae12a0d 3011{
068f4070 3012 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 3013
3014 int status;
3015 struct spi_message message;
bdff549e 3016 struct spi_transfer x[2];
8ae12a0d
DB		 3017 u8 *local_buf;
3018
b3a223ee
MB		 3019 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3020 * copying here, (as a pure convenience thing), but we can
3021 * keep heap costs out of the hot path unless someone else is
3022 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 3023 */
b3a223ee 3024 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 3025 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3026 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 3027 if (!local_buf)
3028 return -ENOMEM;
3029 } else {
3030 local_buf = buf;
3031 }
8ae12a0d 3032
8275c642 3033 spi_message_init(&message);
5fe5f05e 3034 memset(x, 0, sizeof(x));
bdff549e
DB		 3035 if (n_tx) {
3036 x[0].len = n_tx;
3037 spi_message_add_tail(&x[0], &message);
3038 }
3039 if (n_rx) {
3040 x[1].len = n_rx;
3041 spi_message_add_tail(&x[1], &message);
3042 }
8275c642 3043
8ae12a0d 3044 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 3045 x[0].tx_buf = local_buf;
3046 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 3047
3048 /* do the i/o */
8ae12a0d 3049 status = spi_sync(spi, &message);
9b938b74 3050 if (status == 0)
bdff549e 3051 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 3052
bdff549e 3053 if (x[0].tx_buf == buf)
068f4070 3054 mutex_unlock(&lock);
8ae12a0d
DB		 3055 else
3056 kfree(local_buf);
3057
3058 return status;
3059}
3060EXPORT_SYMBOL_GPL(spi_write_then_read);
3061
3062/*-------------------------------------------------------------------------*/
3063
ce79d54a
PA		 3064#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3065static int __spi_of_device_match(struct device *dev, void *data)
3066{
3067 return dev->of_node == data;
3068}
3069
3070/* must call put_device() when done with returned spi_device device */
3071static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3072{
3073 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3074 __spi_of_device_match);
3075 return dev ? to_spi_device(dev) : NULL;
3076}
3077
3078static int __spi_of_master_match(struct device *dev, const void *data)
3079{
3080 return dev->of_node == data;
3081}
3082
3083/* the spi masters are not using spi_bus, so we find it with another way */
3084static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3085{
3086 struct device *dev;
3087
3088 dev = class_find_device(&spi_master_class, NULL, node,
3089 __spi_of_master_match);
3090 if (!dev)
3091 return NULL;
3092
3093 /* reference got in class_find_device */
3094 return container_of(dev, struct spi_master, dev);
3095}
3096
3097static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3098 void *arg)
3099{
3100 struct of_reconfig_data *rd = arg;
3101 struct spi_master *master;
3102 struct spi_device *spi;
3103
3104 switch (of_reconfig_get_state_change(action, arg)) {
3105 case OF_RECONFIG_CHANGE_ADD:
3106 master = of_find_spi_master_by_node(rd->dn->parent);
3107 if (master == NULL)
3108 return NOTIFY_OK; /* not for us */
3109
bd6c1644
GU		 3110 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3111 put_device(&master->dev);
3112 return NOTIFY_OK;
3113 }
3114
ce79d54a
PA		 3115 spi = of_register_spi_device(master, rd->dn);
3116 put_device(&master->dev);
3117
3118 if (IS_ERR(spi)) {
3119 pr_err("%s: failed to create for '%s'\n",
3120 __func__, rd->dn->full_name);
3121 return notifier_from_errno(PTR_ERR(spi));
3122 }
3123 break;
3124
3125 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3126 /* already depopulated? */
3127 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3128 return NOTIFY_OK;
3129
ce79d54a
PA		 3130 /* find our device by node */
3131 spi = of_find_spi_device_by_node(rd->dn);
3132 if (spi == NULL)
3133 return NOTIFY_OK; /* no? not meant for us */
3134
3135 /* unregister takes one ref away */
3136 spi_unregister_device(spi);
3137
3138 /* and put the reference of the find */
3139 put_device(&spi->dev);
3140 break;
3141 }
3142
3143 return NOTIFY_OK;
3144}
3145
3146static struct notifier_block spi_of_notifier = {
3147 .notifier_call = of_spi_notify,
3148};
3149#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3150extern struct notifier_block spi_of_notifier;
3151#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3152
7f24467f
OP		 3153#if IS_ENABLED(CONFIG_ACPI)
3154static int spi_acpi_master_match(struct device *dev, const void *data)
3155{
3156 return ACPI_COMPANION(dev->parent) == data;
3157}
3158
3159static int spi_acpi_device_match(struct device *dev, void *data)
3160{
3161 return ACPI_COMPANION(dev) == data;
3162}
3163
3164static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3165{
3166 struct device *dev;
3167
3168 dev = class_find_device(&spi_master_class, NULL, adev,
3169 spi_acpi_master_match);
3170 if (!dev)
3171 return NULL;
3172
3173 return container_of(dev, struct spi_master, dev);
3174}
3175
3176static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3177{
3178 struct device *dev;
3179
3180 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3181
3182 return dev ? to_spi_device(dev) : NULL;
3183}
3184
3185static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3186 void *arg)
3187{
3188 struct acpi_device *adev = arg;
3189 struct spi_master *master;
3190 struct spi_device *spi;
3191
3192 switch (value) {
3193 case ACPI_RECONFIG_DEVICE_ADD:
3194 master = acpi_spi_find_master_by_adev(adev->parent);
3195 if (!master)
3196 break;
3197
3198 acpi_register_spi_device(master, adev);
3199 put_device(&master->dev);
3200 break;
3201 case ACPI_RECONFIG_DEVICE_REMOVE:
3202 if (!acpi_device_enumerated(adev))
3203 break;
3204
3205 spi = acpi_spi_find_device_by_adev(adev);
3206 if (!spi)
3207 break;
3208
3209 spi_unregister_device(spi);
3210 put_device(&spi->dev);
3211 break;
3212 }
3213
3214 return NOTIFY_OK;
3215}
3216
3217static struct notifier_block spi_acpi_notifier = {
3218 .notifier_call = acpi_spi_notify,
3219};
3220#else
3221extern struct notifier_block spi_acpi_notifier;
3222#endif
3223
8ae12a0d
DB		 3224static int __init spi_init(void)
3225{
b885244e
DB		 3226 int status;
3227
e94b1766 3228 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3229 if (!buf) {
3230 status = -ENOMEM;
3231 goto err0;
3232 }
3233
3234 status = bus_register(&spi_bus_type);
3235 if (status < 0)
3236 goto err1;
8ae12a0d 3237
b885244e
DB		 3238 status = class_register(&spi_master_class);
3239 if (status < 0)
3240 goto err2;
ce79d54a 3241
5267720e 3242 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a 3243 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
7f24467f
OP		 3244 if (IS_ENABLED(CONFIG_ACPI))
3245 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
ce79d54a 3246
8ae12a0d 3247 return 0;
b885244e
DB		 3248
3249err2:
3250 bus_unregister(&spi_bus_type);
3251err1:
3252 kfree(buf);
3253 buf = NULL;
3254err0:
3255 return status;
8ae12a0d 3256}
b885244e 3257
8ae12a0d
DB		 3258/* board_info is normally registered in arch_initcall(),
3259 * but even essential drivers wait till later
b885244e
DB		 3260 *
3261 * REVISIT only boardinfo really needs static linking. the rest (device and
3262 * driver registration) _could_ be dynamically linked (modular) ... costs
3263 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3264 */
673c0c00 3265postcore_initcall(spi_init);
8ae12a0d 3266
Linux kernel - Deliverables
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