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Merge remote-tracking branch 'lightnvm/for-next'
[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);
764f2166 1166 mutex_unlock(&master->io_mutex);
49834de2
MB		 1167 return;
1168 }
1169 }
1170
56ec1978
MB		 1171 if (!was_busy)
1172 trace_spi_master_busy(master);
1173
7dfd2bd7 1174 if (!was_busy && master->prepare_transfer_hardware) {
ffbbdd21
LW		 1175 ret = master->prepare_transfer_hardware(master);
1176 if (ret) {
1177 dev_err(&master->dev,
1178 "failed to prepare transfer hardware\n");
49834de2
MB		 1179
1180 if (master->auto_runtime_pm)
1181 pm_runtime_put(master->dev.parent);
764f2166 1182 mutex_unlock(&master->io_mutex);
ffbbdd21
LW		 1183 return;
1184 }
1185 }
1186
56ec1978
MB		 1187 trace_spi_message_start(master->cur_msg);
1188
2841a5fc
MB		 1189 if (master->prepare_message) {
1190 ret = master->prepare_message(master, master->cur_msg);
1191 if (ret) {
1192 dev_err(&master->dev,
1193 "failed to prepare message: %d\n", ret);
1194 master->cur_msg->status = ret;
1195 spi_finalize_current_message(master);
49023d2e 1196 goto out;
2841a5fc
MB		 1197 }
1198 master->cur_msg_prepared = true;
1199 }
1200
99adef31
MB		 1201 ret = spi_map_msg(master, master->cur_msg);
1202 if (ret) {
1203 master->cur_msg->status = ret;
1204 spi_finalize_current_message(master);
49023d2e 1205 goto out;
99adef31
MB		 1206 }
1207
ffbbdd21
LW		 1208 ret = master->transfer_one_message(master, master->cur_msg);
1209 if (ret) {
1210 dev_err(&master->dev,
1f802f82 1211 "failed to transfer one message from queue\n");
49023d2e 1212 goto out;
ffbbdd21 1213 }
49023d2e
JH		 1214
1215out:
ef4d96ec 1216 mutex_unlock(&master->io_mutex);
62826970
MB		 1217
1218 /* Prod the scheduler in case transfer_one() was busy waiting */
49023d2e
JH		 1219 if (!ret)
1220 cond_resched();
ffbbdd21
LW		 1221}
1222
fc9e0f71
MB		 1223/**
1224 * spi_pump_messages - kthread work function which processes spi message queue
1225 * @work: pointer to kthread work struct contained in the master struct
1226 */
1227static void spi_pump_messages(struct kthread_work *work)
1228{
1229 struct spi_master *master =
1230 container_of(work, struct spi_master, pump_messages);
1231
ef4d96ec 1232 __spi_pump_messages(master, true);
fc9e0f71
MB		 1233}
1234
ffbbdd21
LW		 1235static int spi_init_queue(struct spi_master *master)
1236{
1237 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1238
ffbbdd21
LW		 1239 master->running = false;
1240 master->busy = false;
1241
1242 init_kthread_worker(&master->kworker);
1243 master->kworker_task = kthread_run(kthread_worker_fn,
f170168b 1244 &master->kworker, "%s",
ffbbdd21
LW		 1245 dev_name(&master->dev));
1246 if (IS_ERR(master->kworker_task)) {
1247 dev_err(&master->dev, "failed to create message pump task\n");
98a8f5a0 1248 return PTR_ERR(master->kworker_task);
ffbbdd21
LW		 1249 }
1250 init_kthread_work(&master->pump_messages, spi_pump_messages);
1251
1252 /*
1253 * Master config will indicate if this controller should run the
1254 * message pump with high (realtime) priority to reduce the transfer
1255 * latency on the bus by minimising the delay between a transfer
1256 * request and the scheduling of the message pump thread. Without this
1257 * setting the message pump thread will remain at default priority.
1258 */
1259 if (master->rt) {
1260 dev_info(&master->dev,
1261 "will run message pump with realtime priority\n");
1262 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1263 }
1264
1265 return 0;
1266}
1267
1268/**
1269 * spi_get_next_queued_message() - called by driver to check for queued
1270 * messages
1271 * @master: the master to check for queued messages
1272 *
1273 * If there are more messages in the queue, the next message is returned from
1274 * this call.
97d56dc6
JMC		 1275 *
1276 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21
LW		 1277 */
1278struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1279{
1280 struct spi_message *next;
1281 unsigned long flags;
1282
1283 /* get a pointer to the next message, if any */
1284 spin_lock_irqsave(&master->queue_lock, flags);
1cfd97f9
AL		 1285 next = list_first_entry_or_null(&master->queue, struct spi_message,
1286 queue);
ffbbdd21
LW		 1287 spin_unlock_irqrestore(&master->queue_lock, flags);
1288
1289 return next;
1290}
1291EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1292
1293/**
1294 * spi_finalize_current_message() - the current message is complete
1295 * @master: the master to return the message to
1296 *
1297 * Called by the driver to notify the core that the message in the front of the
1298 * queue is complete and can be removed from the queue.
1299 */
1300void spi_finalize_current_message(struct spi_master *master)
1301{
1302 struct spi_message *mesg;
1303 unsigned long flags;
2841a5fc 1304 int ret;
ffbbdd21
LW		 1305
1306 spin_lock_irqsave(&master->queue_lock, flags);
1307 mesg = master->cur_msg;
ffbbdd21
LW		 1308 spin_unlock_irqrestore(&master->queue_lock, flags);
1309
99adef31
MB		 1310 spi_unmap_msg(master, mesg);
1311
2841a5fc
MB		 1312 if (master->cur_msg_prepared && master->unprepare_message) {
1313 ret = master->unprepare_message(master, mesg);
1314 if (ret) {
1315 dev_err(&master->dev,
1316 "failed to unprepare message: %d\n", ret);
1317 }
1318 }
391949b6 1319
8e76ef88
MS		 1320 spin_lock_irqsave(&master->queue_lock, flags);
1321 master->cur_msg = NULL;
2841a5fc 1322 master->cur_msg_prepared = false;
8e76ef88
MS		 1323 queue_kthread_work(&master->kworker, &master->pump_messages);
1324 spin_unlock_irqrestore(&master->queue_lock, flags);
1325
1326 trace_spi_message_done(mesg);
2841a5fc 1327
ffbbdd21
LW		 1328 mesg->state = NULL;
1329 if (mesg->complete)
1330 mesg->complete(mesg->context);
1331}
1332EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1333
1334static int spi_start_queue(struct spi_master *master)
1335{
1336 unsigned long flags;
1337
1338 spin_lock_irqsave(&master->queue_lock, flags);
1339
1340 if (master->running || master->busy) {
1341 spin_unlock_irqrestore(&master->queue_lock, flags);
1342 return -EBUSY;
1343 }
1344
1345 master->running = true;
1346 master->cur_msg = NULL;
1347 spin_unlock_irqrestore(&master->queue_lock, flags);
1348
1349 queue_kthread_work(&master->kworker, &master->pump_messages);
1350
1351 return 0;
1352}
1353
1354static int spi_stop_queue(struct spi_master *master)
1355{
1356 unsigned long flags;
1357 unsigned limit = 500;
1358 int ret = 0;
1359
1360 spin_lock_irqsave(&master->queue_lock, flags);
1361
1362 /*
1363 * This is a bit lame, but is optimized for the common execution path.
1364 * A wait_queue on the master->busy could be used, but then the common
1365 * execution path (pump_messages) would be required to call wake_up or
1366 * friends on every SPI message. Do this instead.
1367 */
1368 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1369 spin_unlock_irqrestore(&master->queue_lock, flags);
f97b26b0 1370 usleep_range(10000, 11000);
ffbbdd21
LW		 1371 spin_lock_irqsave(&master->queue_lock, flags);
1372 }
1373
1374 if (!list_empty(&master->queue) || master->busy)
1375 ret = -EBUSY;
1376 else
1377 master->running = false;
1378
1379 spin_unlock_irqrestore(&master->queue_lock, flags);
1380
1381 if (ret) {
1382 dev_warn(&master->dev,
1383 "could not stop message queue\n");
1384 return ret;
1385 }
1386 return ret;
1387}
1388
1389static int spi_destroy_queue(struct spi_master *master)
1390{
1391 int ret;
1392
1393 ret = spi_stop_queue(master);
1394
1395 /*
1396 * flush_kthread_worker will block until all work is done.
1397 * If the reason that stop_queue timed out is that the work will never
1398 * finish, then it does no good to call flush/stop thread, so
1399 * return anyway.
1400 */
1401 if (ret) {
1402 dev_err(&master->dev, "problem destroying queue\n");
1403 return ret;
1404 }
1405
1406 flush_kthread_worker(&master->kworker);
1407 kthread_stop(master->kworker_task);
1408
1409 return 0;
1410}
1411
0461a414
MB		 1412static int __spi_queued_transfer(struct spi_device *spi,
1413 struct spi_message *msg,
1414 bool need_pump)
ffbbdd21
LW		 1415{
1416 struct spi_master *master = spi->master;
1417 unsigned long flags;
1418
1419 spin_lock_irqsave(&master->queue_lock, flags);
1420
1421 if (!master->running) {
1422 spin_unlock_irqrestore(&master->queue_lock, flags);
1423 return -ESHUTDOWN;
1424 }
1425 msg->actual_length = 0;
1426 msg->status = -EINPROGRESS;
1427
1428 list_add_tail(&msg->queue, &master->queue);
0461a414 1429 if (!master->busy && need_pump)
ffbbdd21
LW		 1430 queue_kthread_work(&master->kworker, &master->pump_messages);
1431
1432 spin_unlock_irqrestore(&master->queue_lock, flags);
1433 return 0;
1434}
1435
0461a414
MB		 1436/**
1437 * spi_queued_transfer - transfer function for queued transfers
1438 * @spi: spi device which is requesting transfer
1439 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1440 *
1441 * Return: zero on success, else a negative error code.
0461a414
MB		 1442 */
1443static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1444{
1445 return __spi_queued_transfer(spi, msg, true);
1446}
1447
ffbbdd21
LW		 1448static int spi_master_initialize_queue(struct spi_master *master)
1449{
1450 int ret;
1451
ffbbdd21 1452 master->transfer = spi_queued_transfer;
b158935f
MB		 1453 if (!master->transfer_one_message)
1454 master->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1455
1456 /* Initialize and start queue */
1457 ret = spi_init_queue(master);
1458 if (ret) {
1459 dev_err(&master->dev, "problem initializing queue\n");
1460 goto err_init_queue;
1461 }
c3676d5c 1462 master->queued = true;
ffbbdd21
LW		 1463 ret = spi_start_queue(master);
1464 if (ret) {
1465 dev_err(&master->dev, "problem starting queue\n");
1466 goto err_start_queue;
1467 }
1468
1469 return 0;
1470
1471err_start_queue:
ffbbdd21 1472 spi_destroy_queue(master);
c3676d5c 1473err_init_queue:
ffbbdd21
LW		 1474 return ret;
1475}
1476
1477/*-------------------------------------------------------------------------*/
1478
7cb94361 1479#if defined(CONFIG_OF)
aff5e3f8
PA		 1480static struct spi_device *
1481of_register_spi_device(struct spi_master *master, struct device_node *nc)
1482{
1483 struct spi_device *spi;
1484 int rc;
1485 u32 value;
1486
1487 /* Alloc an spi_device */
1488 spi = spi_alloc_device(master);
1489 if (!spi) {
1490 dev_err(&master->dev, "spi_device alloc error for %s\n",
1491 nc->full_name);
1492 rc = -ENOMEM;
1493 goto err_out;
1494 }
1495
1496 /* Select device driver */
1497 rc = of_modalias_node(nc, spi->modalias,
1498 sizeof(spi->modalias));
1499 if (rc < 0) {
1500 dev_err(&master->dev, "cannot find modalias for %s\n",
1501 nc->full_name);
1502 goto err_out;
1503 }
1504
1505 /* Device address */
1506 rc = of_property_read_u32(nc, "reg", &value);
1507 if (rc) {
1508 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1509 nc->full_name, rc);
1510 goto err_out;
1511 }
1512 spi->chip_select = value;
1513
1514 /* Mode (clock phase/polarity/etc.) */
1515 if (of_find_property(nc, "spi-cpha", NULL))
1516 spi->mode |= SPI_CPHA;
1517 if (of_find_property(nc, "spi-cpol", NULL))
1518 spi->mode |= SPI_CPOL;
1519 if (of_find_property(nc, "spi-cs-high", NULL))
1520 spi->mode |= SPI_CS_HIGH;
1521 if (of_find_property(nc, "spi-3wire", NULL))
1522 spi->mode |= SPI_3WIRE;
1523 if (of_find_property(nc, "spi-lsb-first", NULL))
1524 spi->mode |= SPI_LSB_FIRST;
1525
1526 /* Device DUAL/QUAD mode */
1527 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1528 switch (value) {
1529 case 1:
1530 break;
1531 case 2:
1532 spi->mode |= SPI_TX_DUAL;
1533 break;
1534 case 4:
1535 spi->mode |= SPI_TX_QUAD;
1536 break;
1537 default:
1538 dev_warn(&master->dev,
1539 "spi-tx-bus-width %d not supported\n",
1540 value);
1541 break;
1542 }
1543 }
1544
1545 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1546 switch (value) {
1547 case 1:
1548 break;
1549 case 2:
1550 spi->mode |= SPI_RX_DUAL;
1551 break;
1552 case 4:
1553 spi->mode |= SPI_RX_QUAD;
1554 break;
1555 default:
1556 dev_warn(&master->dev,
1557 "spi-rx-bus-width %d not supported\n",
1558 value);
1559 break;
1560 }
1561 }
1562
1563 /* Device speed */
1564 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1565 if (rc) {
1566 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1567 nc->full_name, rc);
1568 goto err_out;
1569 }
1570 spi->max_speed_hz = value;
1571
aff5e3f8
PA		 1572 /* Store a pointer to the node in the device structure */
1573 of_node_get(nc);
1574 spi->dev.of_node = nc;
1575
1576 /* Register the new device */
aff5e3f8
PA		 1577 rc = spi_add_device(spi);
1578 if (rc) {
1579 dev_err(&master->dev, "spi_device register error %s\n",
1580 nc->full_name);
1581 goto err_out;
1582 }
1583
1584 return spi;
1585
1586err_out:
1587 spi_dev_put(spi);
1588 return ERR_PTR(rc);
1589}
1590
d57a4282
GL		 1591/**
1592 * of_register_spi_devices() - Register child devices onto the SPI bus
1593 * @master: Pointer to spi_master device
1594 *
1595 * Registers an spi_device for each child node of master node which has a 'reg'
1596 * property.
1597 */
1598static void of_register_spi_devices(struct spi_master *master)
1599{
1600 struct spi_device *spi;
1601 struct device_node *nc;
d57a4282
GL		 1602
1603 if (!master->dev.of_node)
1604 return;
1605
f3b6159e 1606 for_each_available_child_of_node(master->dev.of_node, nc) {
bd6c1644
GU		 1607 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1608 continue;
aff5e3f8
PA		 1609 spi = of_register_spi_device(master, nc);
1610 if (IS_ERR(spi))
1611 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
d57a4282 1612 nc->full_name);
d57a4282
GL		 1613 }
1614}
1615#else
1616static void of_register_spi_devices(struct spi_master *master) { }
1617#endif
1618
64bee4d2
MW		 1619#ifdef CONFIG_ACPI
1620static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1621{
1622 struct spi_device *spi = data;
a0a90718 1623 struct spi_master *master = spi->master;
64bee4d2
MW		 1624
1625 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1626 struct acpi_resource_spi_serialbus *sb;
1627
1628 sb = &ares->data.spi_serial_bus;
1629 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
a0a90718
MW		 1630 /*
1631 * ACPI DeviceSelection numbering is handled by the
1632 * host controller driver in Windows and can vary
1633 * from driver to driver. In Linux we always expect
1634 * 0 .. max - 1 so we need to ask the driver to
1635 * translate between the two schemes.
1636 */
1637 if (master->fw_translate_cs) {
1638 int cs = master->fw_translate_cs(master,
1639 sb->device_selection);
1640 if (cs < 0)
1641 return cs;
1642 spi->chip_select = cs;
1643 } else {
1644 spi->chip_select = sb->device_selection;
1645 }
1646
64bee4d2
MW		 1647 spi->max_speed_hz = sb->connection_speed;
1648
1649 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1650 spi->mode |= SPI_CPHA;
1651 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1652 spi->mode |= SPI_CPOL;
1653 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1654 spi->mode |= SPI_CS_HIGH;
1655 }
1656 } else if (spi->irq < 0) {
1657 struct resource r;
1658
1659 if (acpi_dev_resource_interrupt(ares, 0, &r))
1660 spi->irq = r.start;
1661 }
1662
1663 /* Always tell the ACPI core to skip this resource */
1664 return 1;
1665}
1666
7f24467f
OP		 1667static acpi_status acpi_register_spi_device(struct spi_master *master,
1668 struct acpi_device *adev)
64bee4d2 1669{
64bee4d2 1670 struct list_head resource_list;
64bee4d2
MW		 1671 struct spi_device *spi;
1672 int ret;
1673
7f24467f
OP		 1674 if (acpi_bus_get_status(adev) || !adev->status.present ||
1675 acpi_device_enumerated(adev))
64bee4d2
MW		 1676 return AE_OK;
1677
1678 spi = spi_alloc_device(master);
1679 if (!spi) {
1680 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1681 dev_name(&adev->dev));
1682 return AE_NO_MEMORY;
1683 }
1684
7b199811 1685 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1686 spi->irq = -1;
1687
1688 INIT_LIST_HEAD(&resource_list);
1689 ret = acpi_dev_get_resources(adev, &resource_list,
1690 acpi_spi_add_resource, spi);
1691 acpi_dev_free_resource_list(&resource_list);
1692
1693 if (ret < 0 || !spi->max_speed_hz) {
1694 spi_dev_put(spi);
1695 return AE_OK;
1696 }
1697
33ada67d
CR		 1698 if (spi->irq < 0)
1699 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1700
7f24467f
OP		 1701 acpi_device_set_enumerated(adev);
1702
33cf00e5 1703 adev->power.flags.ignore_parent = true;
cf9eb39c 1704 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
64bee4d2 1705 if (spi_add_device(spi)) {
33cf00e5 1706 adev->power.flags.ignore_parent = false;
64bee4d2
MW		 1707 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1708 dev_name(&adev->dev));
1709 spi_dev_put(spi);
1710 }
1711
1712 return AE_OK;
1713}
1714
7f24467f
OP		 1715static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1716 void *data, void **return_value)
1717{
1718 struct spi_master *master = data;
1719 struct acpi_device *adev;
1720
1721 if (acpi_bus_get_device(handle, &adev))
1722 return AE_OK;
1723
1724 return acpi_register_spi_device(master, adev);
1725}
1726
64bee4d2
MW		 1727static void acpi_register_spi_devices(struct spi_master *master)
1728{
1729 acpi_status status;
1730 acpi_handle handle;
1731
29896178 1732 handle = ACPI_HANDLE(master->dev.parent);
64bee4d2
MW		 1733 if (!handle)
1734 return;
1735
1736 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1737 acpi_spi_add_device, NULL,
1738 master, NULL);
1739 if (ACPI_FAILURE(status))
1740 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1741}
1742#else
1743static inline void acpi_register_spi_devices(struct spi_master *master) {}
1744#endif /* CONFIG_ACPI */
1745
49dce689 1746static void spi_master_release(struct device *dev)
8ae12a0d
DB		 1747{
1748 struct spi_master *master;
1749
49dce689 1750 master = container_of(dev, struct spi_master, dev);
8ae12a0d
DB		 1751 kfree(master);
1752}
1753
1754static struct class spi_master_class = {
1755 .name = "spi_master",
1756 .owner = THIS_MODULE,
49dce689 1757 .dev_release = spi_master_release,
eca2ebc7 1758 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1759};
1760
1761
1762/**
1763 * spi_alloc_master - allocate SPI master controller
1764 * @dev: the controller, possibly using the platform_bus
33e34dc6 1765 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 1766 * memory is in the driver_data field of the returned device,
0c868461 1767 * accessible with spi_master_get_devdata().
33e34dc6 1768 * Context: can sleep
8ae12a0d
DB		 1769 *
1770 * This call is used only by SPI master controller drivers, which are the
1771 * only ones directly touching chip registers. It's how they allocate
ba1a0513 1772 * an spi_master structure, prior to calling spi_register_master().
8ae12a0d 1773 *
97d56dc6 1774 * This must be called from context that can sleep.
8ae12a0d
DB		 1775 *
1776 * The caller is responsible for assigning the bus number and initializing
ba1a0513 1777 * the master's methods before calling spi_register_master(); and (after errors
a394d635 1778 * adding the device) calling spi_master_put() to prevent a memory leak.
97d56dc6
JMC		 1779 *
1780 * Return: the SPI master structure on success, else NULL.
8ae12a0d 1781 */
e9d5a461 1782struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
8ae12a0d
DB		 1783{
1784 struct spi_master *master;
1785
0c868461
DB		 1786 if (!dev)
1787 return NULL;
1788
5fe5f05e 1789 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
8ae12a0d
DB		 1790 if (!master)
1791 return NULL;
1792
49dce689 1793 device_initialize(&master->dev);
1e8a52e1
GL		 1794 master->bus_num = -1;
1795 master->num_chipselect = 1;
49dce689 1796 master->dev.class = &spi_master_class;
157f38f9 1797 master->dev.parent = dev;
d7e2ee25 1798 pm_suspend_ignore_children(&master->dev, true);
0c868461 1799 spi_master_set_devdata(master, &master[1]);
8ae12a0d
DB		 1800
1801 return master;
1802}
1803EXPORT_SYMBOL_GPL(spi_alloc_master);
1804
74317984
JCPV		 1805#ifdef CONFIG_OF
1806static int of_spi_register_master(struct spi_master *master)
1807{
e80beb27 1808 int nb, i, *cs;
74317984
JCPV		 1809 struct device_node *np = master->dev.of_node;
1810
1811 if (!np)
1812 return 0;
1813
1814 nb = of_gpio_named_count(np, "cs-gpios");
5fe5f05e 1815 master->num_chipselect = max_t(int, nb, master->num_chipselect);
74317984 1816
8ec5d84e
AL		 1817 /* Return error only for an incorrectly formed cs-gpios property */
1818 if (nb == 0 || nb == -ENOENT)
74317984 1819 return 0;
8ec5d84e
AL		 1820 else if (nb < 0)
1821 return nb;
74317984
JCPV		 1822
1823 cs = devm_kzalloc(&master->dev,
1824 sizeof(int) * master->num_chipselect,
1825 GFP_KERNEL);
1826 master->cs_gpios = cs;
1827
1828 if (!master->cs_gpios)
1829 return -ENOMEM;
1830
0da83bb1 1831 for (i = 0; i < master->num_chipselect; i++)
446411e1 1832 cs[i] = -ENOENT;
74317984
JCPV		 1833
1834 for (i = 0; i < nb; i++)
1835 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1836
1837 return 0;
1838}
1839#else
1840static int of_spi_register_master(struct spi_master *master)
1841{
1842 return 0;
1843}
1844#endif
1845
8ae12a0d
DB		 1846/**
1847 * spi_register_master - register SPI master controller
1848 * @master: initialized master, originally from spi_alloc_master()
33e34dc6 1849 * Context: can sleep
8ae12a0d
DB		 1850 *
1851 * SPI master controllers connect to their drivers using some non-SPI bus,
1852 * such as the platform bus. The final stage of probe() in that code
1853 * includes calling spi_register_master() to hook up to this SPI bus glue.
1854 *
1855 * SPI controllers use board specific (often SOC specific) bus numbers,
1856 * and board-specific addressing for SPI devices combines those numbers
1857 * with chip select numbers. Since SPI does not directly support dynamic
1858 * device identification, boards need configuration tables telling which
1859 * chip is at which address.
1860 *
1861 * This must be called from context that can sleep. It returns zero on
1862 * success, else a negative error code (dropping the master's refcount).
0c868461
DB		 1863 * After a successful return, the caller is responsible for calling
1864 * spi_unregister_master().
97d56dc6
JMC		 1865 *
1866 * Return: zero on success, else a negative error code.
8ae12a0d 1867 */
e9d5a461 1868int spi_register_master(struct spi_master *master)
8ae12a0d 1869{
e44a45ae 1870 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
49dce689 1871 struct device *dev = master->dev.parent;
2b9603a0 1872 struct boardinfo *bi;
8ae12a0d
DB		 1873 int status = -ENODEV;
1874 int dynamic = 0;
1875
0c868461
DB		 1876 if (!dev)
1877 return -ENODEV;
1878
74317984
JCPV		 1879 status = of_spi_register_master(master);
1880 if (status)
1881 return status;
1882
082c8cb4
DB		 1883 /* even if it's just one always-selected device, there must
1884 * be at least one chipselect
1885 */
1886 if (master->num_chipselect == 0)
1887 return -EINVAL;
1888
bb29785e
GL		 1889 if ((master->bus_num < 0) && master->dev.of_node)
1890 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1891
8ae12a0d 1892 /* convention: dynamically assigned bus IDs count down from the max */
a020ed75 1893 if (master->bus_num < 0) {
082c8cb4
DB		 1894 /* FIXME switch to an IDR based scheme, something like
1895 * I2C now uses, so we can't run out of "dynamic" IDs
1896 */
8ae12a0d 1897 master->bus_num = atomic_dec_return(&dyn_bus_id);
b885244e 1898 dynamic = 1;
8ae12a0d
DB		 1899 }
1900
5424d43e
MB		 1901 INIT_LIST_HEAD(&master->queue);
1902 spin_lock_init(&master->queue_lock);
cf32b71e
ES		 1903 spin_lock_init(&master->bus_lock_spinlock);
1904 mutex_init(&master->bus_lock_mutex);
ef4d96ec 1905 mutex_init(&master->io_mutex);
cf32b71e 1906 master->bus_lock_flag = 0;
b158935f 1907 init_completion(&master->xfer_completion);
6ad45a27
MB		 1908 if (!master->max_dma_len)
1909 master->max_dma_len = INT_MAX;
cf32b71e 1910
8ae12a0d
DB		 1911 /* register the device, then userspace will see it.
1912 * registration fails if the bus ID is in use.
1913 */
35f74fca 1914 dev_set_name(&master->dev, "spi%u", master->bus_num);
49dce689 1915 status = device_add(&master->dev);
b885244e 1916 if (status < 0)
8ae12a0d 1917 goto done;
35f74fca 1918 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
8ae12a0d
DB		 1919 dynamic ? " (dynamic)" : "");
1920
ffbbdd21
LW		 1921 /* If we're using a queued driver, start the queue */
1922 if (master->transfer)
1923 dev_info(dev, "master is unqueued, this is deprecated\n");
1924 else {
1925 status = spi_master_initialize_queue(master);
1926 if (status) {
e93b0724 1927 device_del(&master->dev);
ffbbdd21
LW		 1928 goto done;
1929 }
1930 }
eca2ebc7
MS		 1931 /* add statistics */
1932 spin_lock_init(&master->statistics.lock);
ffbbdd21 1933
2b9603a0
FT		 1934 mutex_lock(&board_lock);
1935 list_add_tail(&master->list, &spi_master_list);
1936 list_for_each_entry(bi, &board_list, list)
1937 spi_match_master_to_boardinfo(master, &bi->board_info);
1938 mutex_unlock(&board_lock);
1939
64bee4d2 1940 /* Register devices from the device tree and ACPI */
12b15e83 1941 of_register_spi_devices(master);
64bee4d2 1942 acpi_register_spi_devices(master);
8ae12a0d
DB		 1943done:
1944 return status;
1945}
1946EXPORT_SYMBOL_GPL(spi_register_master);
1947
666d5b4c
MB		 1948static void devm_spi_unregister(struct device *dev, void *res)
1949{
1950 spi_unregister_master(*(struct spi_master **)res);
1951}
1952
1953/**
1954 * dev_spi_register_master - register managed SPI master controller
1955 * @dev: device managing SPI master
1956 * @master: initialized master, originally from spi_alloc_master()
1957 * Context: can sleep
1958 *
1959 * Register a SPI device as with spi_register_master() which will
1960 * automatically be unregister
97d56dc6
JMC		 1961 *
1962 * Return: zero on success, else a negative error code.
666d5b4c
MB		 1963 */
1964int devm_spi_register_master(struct device *dev, struct spi_master *master)
1965{
1966 struct spi_master **ptr;
1967 int ret;
1968
1969 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1970 if (!ptr)
1971 return -ENOMEM;
1972
1973 ret = spi_register_master(master);
4b92894e 1974 if (!ret) {
666d5b4c
MB		 1975 *ptr = master;
1976 devres_add(dev, ptr);
1977 } else {
1978 devres_free(ptr);
1979 }
1980
1981 return ret;
1982}
1983EXPORT_SYMBOL_GPL(devm_spi_register_master);
1984
34860089 1985static int __unregister(struct device *dev, void *null)
8ae12a0d 1986{
34860089 1987 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 1988 return 0;
1989}
1990
1991/**
1992 * spi_unregister_master - unregister SPI master controller
1993 * @master: the master being unregistered
33e34dc6 1994 * Context: can sleep
8ae12a0d
DB		 1995 *
1996 * This call is used only by SPI master controller drivers, which are the
1997 * only ones directly touching chip registers.
1998 *
1999 * This must be called from context that can sleep.
2000 */
2001void spi_unregister_master(struct spi_master *master)
2002{
89fc9a1a
JG		 2003 int dummy;
2004
ffbbdd21
LW		 2005 if (master->queued) {
2006 if (spi_destroy_queue(master))
2007 dev_err(&master->dev, "queue remove failed\n");
2008 }
2009
2b9603a0
FT		 2010 mutex_lock(&board_lock);
2011 list_del(&master->list);
2012 mutex_unlock(&board_lock);
2013
97dbf37d 2014 dummy = device_for_each_child(&master->dev, NULL, __unregister);
49dce689 2015 device_unregister(&master->dev);
8ae12a0d
DB		 2016}
2017EXPORT_SYMBOL_GPL(spi_unregister_master);
2018
ffbbdd21
LW		 2019int spi_master_suspend(struct spi_master *master)
2020{
2021 int ret;
2022
2023 /* Basically no-ops for non-queued masters */
2024 if (!master->queued)
2025 return 0;
2026
2027 ret = spi_stop_queue(master);
2028 if (ret)
2029 dev_err(&master->dev, "queue stop failed\n");
2030
2031 return ret;
2032}
2033EXPORT_SYMBOL_GPL(spi_master_suspend);
2034
2035int spi_master_resume(struct spi_master *master)
2036{
2037 int ret;
2038
2039 if (!master->queued)
2040 return 0;
2041
2042 ret = spi_start_queue(master);
2043 if (ret)
2044 dev_err(&master->dev, "queue restart failed\n");
2045
2046 return ret;
2047}
2048EXPORT_SYMBOL_GPL(spi_master_resume);
2049
9f3b795a 2050static int __spi_master_match(struct device *dev, const void *data)
5ed2c832
DY		 2051{
2052 struct spi_master *m;
9f3b795a 2053 const u16 *bus_num = data;
5ed2c832
DY		 2054
2055 m = container_of(dev, struct spi_master, dev);
2056 return m->bus_num == *bus_num;
2057}
2058
8ae12a0d
DB		 2059/**
2060 * spi_busnum_to_master - look up master associated with bus_num
2061 * @bus_num: the master's bus number
33e34dc6 2062 * Context: can sleep
8ae12a0d
DB		 2063 *
2064 * This call may be used with devices that are registered after
2065 * arch init time. It returns a refcounted pointer to the relevant
2066 * spi_master (which the caller must release), or NULL if there is
2067 * no such master registered.
97d56dc6
JMC		 2068 *
2069 * Return: the SPI master structure on success, else NULL.
8ae12a0d
DB		 2070 */
2071struct spi_master *spi_busnum_to_master(u16 bus_num)
2072{
49dce689 2073 struct device *dev;
1e9a51dc 2074 struct spi_master *master = NULL;
5ed2c832 2075
695794ae 2076 dev = class_find_device(&spi_master_class, NULL, &bus_num,
5ed2c832
DY		 2077 __spi_master_match);
2078 if (dev)
2079 master = container_of(dev, struct spi_master, dev);
2080 /* reference got in class_find_device */
1e9a51dc 2081 return master;
8ae12a0d
DB		 2082}
2083EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2084
d780c371
MS		 2085/*-------------------------------------------------------------------------*/
2086
2087/* Core methods for SPI resource management */
2088
2089/**
2090 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2091 * during the processing of a spi_message while using
2092 * spi_transfer_one
2093 * @spi: the spi device for which we allocate memory
2094 * @release: the release code to execute for this resource
2095 * @size: size to alloc and return
2096 * @gfp: GFP allocation flags
2097 *
2098 * Return: the pointer to the allocated data
2099 *
2100 * This may get enhanced in the future to allocate from a memory pool
2101 * of the @spi_device or @spi_master to avoid repeated allocations.
2102 */
2103void *spi_res_alloc(struct spi_device *spi,
2104 spi_res_release_t release,
2105 size_t size, gfp_t gfp)
2106{
2107 struct spi_res *sres;
2108
2109 sres = kzalloc(sizeof(*sres) + size, gfp);
2110 if (!sres)
2111 return NULL;
2112
2113 INIT_LIST_HEAD(&sres->entry);
2114 sres->release = release;
2115
2116 return sres->data;
2117}
2118EXPORT_SYMBOL_GPL(spi_res_alloc);
2119
2120/**
2121 * spi_res_free - free an spi resource
2122 * @res: pointer to the custom data of a resource
2123 *
2124 */
2125void spi_res_free(void *res)
2126{
2127 struct spi_res *sres = container_of(res, struct spi_res, data);
2128
2129 if (!res)
2130 return;
2131
2132 WARN_ON(!list_empty(&sres->entry));
2133 kfree(sres);
2134}
2135EXPORT_SYMBOL_GPL(spi_res_free);
2136
2137/**
2138 * spi_res_add - add a spi_res to the spi_message
2139 * @message: the spi message
2140 * @res: the spi_resource
2141 */
2142void spi_res_add(struct spi_message *message, void *res)
2143{
2144 struct spi_res *sres = container_of(res, struct spi_res, data);
2145
2146 WARN_ON(!list_empty(&sres->entry));
2147 list_add_tail(&sres->entry, &message->resources);
2148}
2149EXPORT_SYMBOL_GPL(spi_res_add);
2150
2151/**
2152 * spi_res_release - release all spi resources for this message
2153 * @master: the @spi_master
2154 * @message: the @spi_message
2155 */
2156void spi_res_release(struct spi_master *master,
2157 struct spi_message *message)
2158{
2159 struct spi_res *res;
2160
2161 while (!list_empty(&message->resources)) {
2162 res = list_last_entry(&message->resources,
2163 struct spi_res, entry);
2164
2165 if (res->release)
2166 res->release(master, message, res->data);
2167
2168 list_del(&res->entry);
2169
2170 kfree(res);
2171 }
2172}
2173EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2174
2175/*-------------------------------------------------------------------------*/
2176
523baf5a
MS		 2177/* Core methods for spi_message alterations */
2178
2179static void __spi_replace_transfers_release(struct spi_master *master,
2180 struct spi_message *msg,
2181 void *res)
2182{
2183 struct spi_replaced_transfers *rxfer = res;
2184 size_t i;
2185
2186 /* call extra callback if requested */
2187 if (rxfer->release)
2188 rxfer->release(master, msg, res);
2189
2190 /* insert replaced transfers back into the message */
2191 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2192
2193 /* remove the formerly inserted entries */
2194 for (i = 0; i < rxfer->inserted; i++)
2195 list_del(&rxfer->inserted_transfers[i].transfer_list);
2196}
2197
2198/**
2199 * spi_replace_transfers - replace transfers with several transfers
2200 * and register change with spi_message.resources
2201 * @msg: the spi_message we work upon
2202 * @xfer_first: the first spi_transfer we want to replace
2203 * @remove: number of transfers to remove
2204 * @insert: the number of transfers we want to insert instead
2205 * @release: extra release code necessary in some circumstances
2206 * @extradatasize: extra data to allocate (with alignment guarantees
2207 * of struct @spi_transfer)
05885397 2208 * @gfp: gfp flags
523baf5a
MS		 2209 *
2210 * Returns: pointer to @spi_replaced_transfers,
2211 * PTR_ERR(...) in case of errors.
2212 */
2213struct spi_replaced_transfers *spi_replace_transfers(
2214 struct spi_message *msg,
2215 struct spi_transfer *xfer_first,
2216 size_t remove,
2217 size_t insert,
2218 spi_replaced_release_t release,
2219 size_t extradatasize,
2220 gfp_t gfp)
2221{
2222 struct spi_replaced_transfers *rxfer;
2223 struct spi_transfer *xfer;
2224 size_t i;
2225
2226 /* allocate the structure using spi_res */
2227 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2228 insert * sizeof(struct spi_transfer)
2229 + sizeof(struct spi_replaced_transfers)
2230 + extradatasize,
2231 gfp);
2232 if (!rxfer)
2233 return ERR_PTR(-ENOMEM);
2234
2235 /* the release code to invoke before running the generic release */
2236 rxfer->release = release;
2237
2238 /* assign extradata */
2239 if (extradatasize)
2240 rxfer->extradata =
2241 &rxfer->inserted_transfers[insert];
2242
2243 /* init the replaced_transfers list */
2244 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2245
2246 /* assign the list_entry after which we should reinsert
2247 * the @replaced_transfers - it may be spi_message.messages!
2248 */
2249 rxfer->replaced_after = xfer_first->transfer_list.prev;
2250
2251 /* remove the requested number of transfers */
2252 for (i = 0; i < remove; i++) {
2253 /* if the entry after replaced_after it is msg->transfers
2254 * then we have been requested to remove more transfers
2255 * than are in the list
2256 */
2257 if (rxfer->replaced_after->next == &msg->transfers) {
2258 dev_err(&msg->spi->dev,
2259 "requested to remove more spi_transfers than are available\n");
2260 /* insert replaced transfers back into the message */
2261 list_splice(&rxfer->replaced_transfers,
2262 rxfer->replaced_after);
2263
2264 /* free the spi_replace_transfer structure */
2265 spi_res_free(rxfer);
2266
2267 /* and return with an error */
2268 return ERR_PTR(-EINVAL);
2269 }
2270
2271 /* remove the entry after replaced_after from list of
2272 * transfers and add it to list of replaced_transfers
2273 */
2274 list_move_tail(rxfer->replaced_after->next,
2275 &rxfer->replaced_transfers);
2276 }
2277
2278 /* create copy of the given xfer with identical settings
2279 * based on the first transfer to get removed
2280 */
2281 for (i = 0; i < insert; i++) {
2282 /* we need to run in reverse order */
2283 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2284
2285 /* copy all spi_transfer data */
2286 memcpy(xfer, xfer_first, sizeof(*xfer));
2287
2288 /* add to list */
2289 list_add(&xfer->transfer_list, rxfer->replaced_after);
2290
2291 /* clear cs_change and delay_usecs for all but the last */
2292 if (i) {
2293 xfer->cs_change = false;
2294 xfer->delay_usecs = 0;
2295 }
2296 }
2297
2298 /* set up inserted */
2299 rxfer->inserted = insert;
2300
2301 /* and register it with spi_res/spi_message */
2302 spi_res_add(msg, rxfer);
2303
2304 return rxfer;
2305}
2306EXPORT_SYMBOL_GPL(spi_replace_transfers);
2307
08933418
FE		 2308static int __spi_split_transfer_maxsize(struct spi_master *master,
2309 struct spi_message *msg,
2310 struct spi_transfer **xferp,
2311 size_t maxsize,
2312 gfp_t gfp)
d9f12122
MS		 2313{
2314 struct spi_transfer *xfer = *xferp, *xfers;
2315 struct spi_replaced_transfers *srt;
2316 size_t offset;
2317 size_t count, i;
2318
2319 /* warn once about this fact that we are splitting a transfer */
2320 dev_warn_once(&msg->spi->dev,
7d62f51e 2321 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
d9f12122
MS		 2322 xfer->len, maxsize);
2323
2324 /* calculate how many we have to replace */
2325 count = DIV_ROUND_UP(xfer->len, maxsize);
2326
2327 /* create replacement */
2328 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2329 if (IS_ERR(srt))
2330 return PTR_ERR(srt);
d9f12122
MS		 2331 xfers = srt->inserted_transfers;
2332
2333 /* now handle each of those newly inserted spi_transfers
2334 * note that the replacements spi_transfers all are preset
2335 * to the same values as *xferp, so tx_buf, rx_buf and len
2336 * are all identical (as well as most others)
2337 * so we just have to fix up len and the pointers.
2338 *
2339 * this also includes support for the depreciated
2340 * spi_message.is_dma_mapped interface
2341 */
2342
2343 /* the first transfer just needs the length modified, so we
2344 * run it outside the loop
2345 */
c8dab77a 2346 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
d9f12122
MS		 2347
2348 /* all the others need rx_buf/tx_buf also set */
2349 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2350 /* update rx_buf, tx_buf and dma */
2351 if (xfers[i].rx_buf)
2352 xfers[i].rx_buf += offset;
2353 if (xfers[i].rx_dma)
2354 xfers[i].rx_dma += offset;
2355 if (xfers[i].tx_buf)
2356 xfers[i].tx_buf += offset;
2357 if (xfers[i].tx_dma)
2358 xfers[i].tx_dma += offset;
2359
2360 /* update length */
2361 xfers[i].len = min(maxsize, xfers[i].len - offset);
2362 }
2363
2364 /* we set up xferp to the last entry we have inserted,
2365 * so that we skip those already split transfers
2366 */
2367 *xferp = &xfers[count - 1];
2368
2369 /* increment statistics counters */
2370 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2371 transfers_split_maxsize);
2372 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2373 transfers_split_maxsize);
2374
2375 return 0;
2376}
2377
2378/**
2379 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2380 * when an individual transfer exceeds a
2381 * certain size
2382 * @master: the @spi_master for this transfer
3700ce95
MI		 2383 * @msg: the @spi_message to transform
2384 * @maxsize: the maximum when to apply this
10f11a22 2385 * @gfp: GFP allocation flags
d9f12122
MS		 2386 *
2387 * Return: status of transformation
2388 */
2389int spi_split_transfers_maxsize(struct spi_master *master,
2390 struct spi_message *msg,
2391 size_t maxsize,
2392 gfp_t gfp)
2393{
2394 struct spi_transfer *xfer;
2395 int ret;
2396
2397 /* iterate over the transfer_list,
2398 * but note that xfer is advanced to the last transfer inserted
2399 * to avoid checking sizes again unnecessarily (also xfer does
2400 * potentiall belong to a different list by the time the
2401 * replacement has happened
2402 */
2403 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2404 if (xfer->len > maxsize) {
2405 ret = __spi_split_transfer_maxsize(
2406 master, msg, &xfer, maxsize, gfp);
2407 if (ret)
2408 return ret;
2409 }
2410 }
2411
2412 return 0;
2413}
2414EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
8ae12a0d
DB		 2415
2416/*-------------------------------------------------------------------------*/
2417
7d077197
DB		 2418/* Core methods for SPI master protocol drivers. Some of the
2419 * other core methods are currently defined as inline functions.
2420 */
2421
63ab645f
SB		 2422static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2423{
2424 if (master->bits_per_word_mask) {
2425 /* Only 32 bits fit in the mask */
2426 if (bits_per_word > 32)
2427 return -EINVAL;
2428 if (!(master->bits_per_word_mask &
2429 SPI_BPW_MASK(bits_per_word)))
2430 return -EINVAL;
2431 }
2432
2433 return 0;
2434}
2435
7d077197
DB		 2436/**
2437 * spi_setup - setup SPI mode and clock rate
2438 * @spi: the device whose settings are being modified
2439 * Context: can sleep, and no requests are queued to the device
2440 *
2441 * SPI protocol drivers may need to update the transfer mode if the
2442 * device doesn't work with its default. They may likewise need
2443 * to update clock rates or word sizes from initial values. This function
2444 * changes those settings, and must be called from a context that can sleep.
2445 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2446 * effect the next time the device is selected and data is transferred to
2447 * or from it. When this function returns, the spi device is deselected.
2448 *
2449 * Note that this call will fail if the protocol driver specifies an option
2450 * that the underlying controller or its driver does not support. For
2451 * example, not all hardware supports wire transfers using nine bit words,
2452 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2453 *
2454 * Return: zero on success, else a negative error code.
7d077197
DB		 2455 */
2456int spi_setup(struct spi_device *spi)
2457{
83596fbe 2458 unsigned bad_bits, ugly_bits;
5ab8d262 2459 int status;
7d077197 2460
f477b7fb 2461 /* check mode to prevent that DUAL and QUAD set at the same time
2462 */
2463 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2464 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2465 dev_err(&spi->dev,
2466 "setup: can not select dual and quad at the same time\n");
2467 return -EINVAL;
2468 }
2469 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2470 */
2471 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2472 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2473 return -EINVAL;
e7db06b5
DB		 2474 /* help drivers fail *cleanly* when they need options
2475 * that aren't supported with their current master
2476 */
2477 bad_bits = spi->mode & ~spi->master->mode_bits;
83596fbe
GU		 2478 ugly_bits = bad_bits &
2479 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2480 if (ugly_bits) {
2481 dev_warn(&spi->dev,
2482 "setup: ignoring unsupported mode bits %x\n",
2483 ugly_bits);
2484 spi->mode &= ~ugly_bits;
2485 bad_bits &= ~ugly_bits;
2486 }
e7db06b5 2487 if (bad_bits) {
eb288a1f 2488 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2489 bad_bits);
2490 return -EINVAL;
2491 }
2492
7d077197
DB		 2493 if (!spi->bits_per_word)
2494 spi->bits_per_word = 8;
2495
5ab8d262
AS		 2496 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2497 if (status)
2498 return status;
63ab645f 2499
052eb2d4
AL		 2500 if (!spi->max_speed_hz)
2501 spi->max_speed_hz = spi->master->max_speed_hz;
2502
caae070c
LD		 2503 if (spi->master->setup)
2504 status = spi->master->setup(spi);
7d077197 2505
abeedb01
FCJ		 2506 spi_set_cs(spi, false);
2507
5fe5f05e 2508 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2509 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2510 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2511 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2512 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2513 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2514 spi->bits_per_word, spi->max_speed_hz,
2515 status);
2516
2517 return status;
2518}
2519EXPORT_SYMBOL_GPL(spi_setup);
2520
90808738 2521static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2522{
2523 struct spi_master *master = spi->master;
e6811d1d 2524 struct spi_transfer *xfer;
6ea31293 2525 int w_size;
cf32b71e 2526
24a0013a
MB		 2527 if (list_empty(&message->transfers))
2528 return -EINVAL;
24a0013a 2529
cf32b71e
ES		 2530 /* Half-duplex links include original MicroWire, and ones with
2531 * only one data pin like SPI_3WIRE (switches direction) or where
2532 * either MOSI or MISO is missing. They can also be caused by
2533 * software limitations.
2534 */
2535 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2536 || (spi->mode & SPI_3WIRE)) {
cf32b71e
ES		 2537 unsigned flags = master->flags;
2538
2539 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2540 if (xfer->rx_buf && xfer->tx_buf)
2541 return -EINVAL;
2542 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2543 return -EINVAL;
2544 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2545 return -EINVAL;
2546 }
2547 }
2548
e6811d1d 2549 /**
059b8ffe
LD		 2550 * Set transfer bits_per_word and max speed as spi device default if
2551 * it is not set for this transfer.
f477b7fb 2552 * Set transfer tx_nbits and rx_nbits as single transfer default
2553 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2554 */
77e80588 2555 message->frame_length = 0;
e6811d1d 2556 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2557 message->frame_length += xfer->len;
e6811d1d
LD		 2558 if (!xfer->bits_per_word)
2559 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2560
2561 if (!xfer->speed_hz)
059b8ffe 2562 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3
MB		 2563 if (!xfer->speed_hz)
2564 xfer->speed_hz = master->max_speed_hz;
a6f87fad
AL		 2565
2566 if (master->max_speed_hz &&
2567 xfer->speed_hz > master->max_speed_hz)
2568 xfer->speed_hz = master->max_speed_hz;
56ede94a 2569
63ab645f
SB		 2570 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2571 return -EINVAL;
a2fd4f9f 2572
4d94bd21
II		 2573 /*
2574 * SPI transfer length should be multiple of SPI word size
2575 * where SPI word size should be power-of-two multiple
2576 */
2577 if (xfer->bits_per_word <= 8)
2578 w_size = 1;
2579 else if (xfer->bits_per_word <= 16)
2580 w_size = 2;
2581 else
2582 w_size = 4;
2583
4d94bd21 2584 /* No partial transfers accepted */
6ea31293 2585 if (xfer->len % w_size)
4d94bd21
II		 2586 return -EINVAL;
2587
a2fd4f9f
MB		 2588 if (xfer->speed_hz && master->min_speed_hz &&
2589 xfer->speed_hz < master->min_speed_hz)
2590 return -EINVAL;
f477b7fb 2591
2592 if (xfer->tx_buf && !xfer->tx_nbits)
2593 xfer->tx_nbits = SPI_NBITS_SINGLE;
2594 if (xfer->rx_buf && !xfer->rx_nbits)
2595 xfer->rx_nbits = SPI_NBITS_SINGLE;
2596 /* check transfer tx/rx_nbits:
1afd9989
GU		 2597 * 1. check the value matches one of single, dual and quad
2598 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 2599 */
db90a441
SP		 2600 if (xfer->tx_buf) {
2601 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2602 xfer->tx_nbits != SPI_NBITS_DUAL &&
2603 xfer->tx_nbits != SPI_NBITS_QUAD)
2604 return -EINVAL;
2605 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2606 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2607 return -EINVAL;
2608 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2609 !(spi->mode & SPI_TX_QUAD))
2610 return -EINVAL;
db90a441 2611 }
f477b7fb 2612 /* check transfer rx_nbits */
db90a441
SP		 2613 if (xfer->rx_buf) {
2614 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2615 xfer->rx_nbits != SPI_NBITS_DUAL &&
2616 xfer->rx_nbits != SPI_NBITS_QUAD)
2617 return -EINVAL;
2618 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2619 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2620 return -EINVAL;
2621 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2622 !(spi->mode & SPI_RX_QUAD))
2623 return -EINVAL;
db90a441 2624 }
e6811d1d
LD		 2625 }
2626
cf32b71e 2627 message->status = -EINPROGRESS;
90808738
MB		 2628
2629 return 0;
2630}
2631
2632static int __spi_async(struct spi_device *spi, struct spi_message *message)
2633{
2634 struct spi_master *master = spi->master;
2635
2636 message->spi = spi;
2637
eca2ebc7
MS		 2638 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2639 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2640
90808738
MB		 2641 trace_spi_message_submit(message);
2642
cf32b71e
ES		 2643 return master->transfer(spi, message);
2644}
2645
568d0697
DB		 2646/**
2647 * spi_async - asynchronous SPI transfer
2648 * @spi: device with which data will be exchanged
2649 * @message: describes the data transfers, including completion callback
2650 * Context: any (irqs may be blocked, etc)
2651 *
2652 * This call may be used in_irq and other contexts which can't sleep,
2653 * as well as from task contexts which can sleep.
2654 *
2655 * The completion callback is invoked in a context which can't sleep.
2656 * Before that invocation, the value of message->status is undefined.
2657 * When the callback is issued, message->status holds either zero (to
2658 * indicate complete success) or a negative error code. After that
2659 * callback returns, the driver which issued the transfer request may
2660 * deallocate the associated memory; it's no longer in use by any SPI
2661 * core or controller driver code.
2662 *
2663 * Note that although all messages to a spi_device are handled in
2664 * FIFO order, messages may go to different devices in other orders.
2665 * Some device might be higher priority, or have various "hard" access
2666 * time requirements, for example.
2667 *
2668 * On detection of any fault during the transfer, processing of
2669 * the entire message is aborted, and the device is deselected.
2670 * Until returning from the associated message completion callback,
2671 * no other spi_message queued to that device will be processed.
2672 * (This rule applies equally to all the synchronous transfer calls,
2673 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2674 *
2675 * Return: zero on success, else a negative error code.
568d0697
DB		 2676 */
2677int spi_async(struct spi_device *spi, struct spi_message *message)
2678{
2679 struct spi_master *master = spi->master;
cf32b71e
ES		 2680 int ret;
2681 unsigned long flags;
568d0697 2682
90808738
MB		 2683 ret = __spi_validate(spi, message);
2684 if (ret != 0)
2685 return ret;
2686
cf32b71e 2687 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
568d0697 2688
cf32b71e
ES		 2689 if (master->bus_lock_flag)
2690 ret = -EBUSY;
2691 else
2692 ret = __spi_async(spi, message);
568d0697 2693
cf32b71e
ES		 2694 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2695
2696 return ret;
568d0697
DB		 2697}
2698EXPORT_SYMBOL_GPL(spi_async);
2699
cf32b71e
ES		 2700/**
2701 * spi_async_locked - version of spi_async with exclusive bus usage
2702 * @spi: device with which data will be exchanged
2703 * @message: describes the data transfers, including completion callback
2704 * Context: any (irqs may be blocked, etc)
2705 *
2706 * This call may be used in_irq and other contexts which can't sleep,
2707 * as well as from task contexts which can sleep.
2708 *
2709 * The completion callback is invoked in a context which can't sleep.
2710 * Before that invocation, the value of message->status is undefined.
2711 * When the callback is issued, message->status holds either zero (to
2712 * indicate complete success) or a negative error code. After that
2713 * callback returns, the driver which issued the transfer request may
2714 * deallocate the associated memory; it's no longer in use by any SPI
2715 * core or controller driver code.
2716 *
2717 * Note that although all messages to a spi_device are handled in
2718 * FIFO order, messages may go to different devices in other orders.
2719 * Some device might be higher priority, or have various "hard" access
2720 * time requirements, for example.
2721 *
2722 * On detection of any fault during the transfer, processing of
2723 * the entire message is aborted, and the device is deselected.
2724 * Until returning from the associated message completion callback,
2725 * no other spi_message queued to that device will be processed.
2726 * (This rule applies equally to all the synchronous transfer calls,
2727 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2728 *
2729 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2730 */
2731int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2732{
2733 struct spi_master *master = spi->master;
2734 int ret;
2735 unsigned long flags;
2736
90808738
MB		 2737 ret = __spi_validate(spi, message);
2738 if (ret != 0)
2739 return ret;
2740
cf32b71e
ES		 2741 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2742
2743 ret = __spi_async(spi, message);
2744
2745 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2746
2747 return ret;
2748
2749}
2750EXPORT_SYMBOL_GPL(spi_async_locked);
2751
7d077197 2752
556351f1
V		 2753int spi_flash_read(struct spi_device *spi,
2754 struct spi_flash_read_message *msg)
2755
2756{
2757 struct spi_master *master = spi->master;
f4502dd1 2758 struct device *rx_dev = NULL;
556351f1
V		 2759 int ret;
2760
2761 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2762 msg->addr_nbits == SPI_NBITS_DUAL) &&
2763 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2764 return -EINVAL;
2765 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2766 msg->addr_nbits == SPI_NBITS_QUAD) &&
2767 !(spi->mode & SPI_TX_QUAD))
2768 return -EINVAL;
2769 if (msg->data_nbits == SPI_NBITS_DUAL &&
2770 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2771 return -EINVAL;
2772 if (msg->data_nbits == SPI_NBITS_QUAD &&
2773 !(spi->mode & SPI_RX_QUAD))
2774 return -EINVAL;
2775
2776 if (master->auto_runtime_pm) {
2777 ret = pm_runtime_get_sync(master->dev.parent);
2778 if (ret < 0) {
2779 dev_err(&master->dev, "Failed to power device: %d\n",
2780 ret);
2781 return ret;
2782 }
2783 }
f4502dd1 2784
556351f1 2785 mutex_lock(&master->bus_lock_mutex);
ef4d96ec 2786 mutex_lock(&master->io_mutex);
f4502dd1
V		 2787 if (master->dma_rx) {
2788 rx_dev = master->dma_rx->device->dev;
2789 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2790 msg->buf, msg->len,
2791 DMA_FROM_DEVICE);
2792 if (!ret)
2793 msg->cur_msg_mapped = true;
2794 }
556351f1 2795 ret = master->spi_flash_read(spi, msg);
f4502dd1
V		 2796 if (msg->cur_msg_mapped)
2797 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2798 DMA_FROM_DEVICE);
ef4d96ec 2799 mutex_unlock(&master->io_mutex);
556351f1 2800 mutex_unlock(&master->bus_lock_mutex);
f4502dd1 2801
556351f1
V		 2802 if (master->auto_runtime_pm)
2803 pm_runtime_put(master->dev.parent);
2804
2805 return ret;
2806}
2807EXPORT_SYMBOL_GPL(spi_flash_read);
2808
7d077197
DB		 2809/*-------------------------------------------------------------------------*/
2810
2811/* Utility methods for SPI master protocol drivers, layered on
2812 * top of the core. Some other utility methods are defined as
2813 * inline functions.
2814 */
2815
5d870c8e
AM		 2816static void spi_complete(void *arg)
2817{
2818 complete(arg);
2819}
2820
ef4d96ec 2821static int __spi_sync(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2822{
2823 DECLARE_COMPLETION_ONSTACK(done);
2824 int status;
2825 struct spi_master *master = spi->master;
0461a414
MB		 2826 unsigned long flags;
2827
2828 status = __spi_validate(spi, message);
2829 if (status != 0)
2830 return status;
cf32b71e
ES		 2831
2832 message->complete = spi_complete;
2833 message->context = &done;
0461a414 2834 message->spi = spi;
cf32b71e 2835
eca2ebc7
MS		 2836 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2837 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2838
0461a414
MB		 2839 /* If we're not using the legacy transfer method then we will
2840 * try to transfer in the calling context so special case.
2841 * This code would be less tricky if we could remove the
2842 * support for driver implemented message queues.
2843 */
2844 if (master->transfer == spi_queued_transfer) {
2845 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2846
2847 trace_spi_message_submit(message);
2848
2849 status = __spi_queued_transfer(spi, message, false);
2850
2851 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2852 } else {
2853 status = spi_async_locked(spi, message);
2854 }
cf32b71e 2855
cf32b71e 2856 if (status == 0) {
0461a414
MB		 2857 /* Push out the messages in the calling context if we
2858 * can.
2859 */
eca2ebc7
MS		 2860 if (master->transfer == spi_queued_transfer) {
2861 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2862 spi_sync_immediate);
2863 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2864 spi_sync_immediate);
ef4d96ec 2865 __spi_pump_messages(master, false);
eca2ebc7 2866 }
0461a414 2867
cf32b71e
ES		 2868 wait_for_completion(&done);
2869 status = message->status;
2870 }
2871 message->context = NULL;
2872 return status;
2873}
2874
8ae12a0d
DB		 2875/**
2876 * spi_sync - blocking/synchronous SPI data transfers
2877 * @spi: device with which data will be exchanged
2878 * @message: describes the data transfers
33e34dc6 2879 * Context: can sleep
8ae12a0d
DB		 2880 *
2881 * This call may only be used from a context that may sleep. The sleep
2882 * is non-interruptible, and has no timeout. Low-overhead controller
2883 * drivers may DMA directly into and out of the message buffers.
2884 *
2885 * Note that the SPI device's chip select is active during the message,
2886 * and then is normally disabled between messages. Drivers for some
2887 * frequently-used devices may want to minimize costs of selecting a chip,
2888 * by leaving it selected in anticipation that the next message will go
2889 * to the same chip. (That may increase power usage.)
2890 *
0c868461
DB		 2891 * Also, the caller is guaranteeing that the memory associated with the
2892 * message will not be freed before this call returns.
2893 *
97d56dc6 2894 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2895 */
2896int spi_sync(struct spi_device *spi, struct spi_message *message)
2897{
ef4d96ec
MB		 2898 int ret;
2899
2900 mutex_lock(&spi->master->bus_lock_mutex);
2901 ret = __spi_sync(spi, message);
2902 mutex_unlock(&spi->master->bus_lock_mutex);
2903
2904 return ret;
8ae12a0d
DB		 2905}
2906EXPORT_SYMBOL_GPL(spi_sync);
2907
cf32b71e
ES		 2908/**
2909 * spi_sync_locked - version of spi_sync with exclusive bus usage
2910 * @spi: device with which data will be exchanged
2911 * @message: describes the data transfers
2912 * Context: can sleep
2913 *
2914 * This call may only be used from a context that may sleep. The sleep
2915 * is non-interruptible, and has no timeout. Low-overhead controller
2916 * drivers may DMA directly into and out of the message buffers.
2917 *
2918 * This call should be used by drivers that require exclusive access to the
25985edc 2919 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 2920 * be released by a spi_bus_unlock call when the exclusive access is over.
2921 *
97d56dc6 2922 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2923 */
2924int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2925{
ef4d96ec 2926 return __spi_sync(spi, message);
cf32b71e
ES		 2927}
2928EXPORT_SYMBOL_GPL(spi_sync_locked);
2929
2930/**
2931 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2932 * @master: SPI bus master that should be locked for exclusive bus access
2933 * Context: can sleep
2934 *
2935 * This call may only be used from a context that may sleep. The sleep
2936 * is non-interruptible, and has no timeout.
2937 *
2938 * This call should be used by drivers that require exclusive access to the
2939 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2940 * exclusive access is over. Data transfer must be done by spi_sync_locked
2941 * and spi_async_locked calls when the SPI bus lock is held.
2942 *
97d56dc6 2943 * Return: always zero.
cf32b71e
ES		 2944 */
2945int spi_bus_lock(struct spi_master *master)
2946{
2947 unsigned long flags;
2948
2949 mutex_lock(&master->bus_lock_mutex);
2950
2951 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2952 master->bus_lock_flag = 1;
2953 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2954
2955 /* mutex remains locked until spi_bus_unlock is called */
2956
2957 return 0;
2958}
2959EXPORT_SYMBOL_GPL(spi_bus_lock);
2960
2961/**
2962 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2963 * @master: SPI bus master that was locked for exclusive bus access
2964 * Context: can sleep
2965 *
2966 * This call may only be used from a context that may sleep. The sleep
2967 * is non-interruptible, and has no timeout.
2968 *
2969 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2970 * call.
2971 *
97d56dc6 2972 * Return: always zero.
cf32b71e
ES		 2973 */
2974int spi_bus_unlock(struct spi_master *master)
2975{
2976 master->bus_lock_flag = 0;
2977
2978 mutex_unlock(&master->bus_lock_mutex);
2979
2980 return 0;
2981}
2982EXPORT_SYMBOL_GPL(spi_bus_unlock);
2983
a9948b61 2984/* portable code must never pass more than 32 bytes */
5fe5f05e 2985#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 2986
2987static u8 *buf;
2988
2989/**
2990 * spi_write_then_read - SPI synchronous write followed by read
2991 * @spi: device with which data will be exchanged
2992 * @txbuf: data to be written (need not be dma-safe)
2993 * @n_tx: size of txbuf, in bytes
27570497
JP		 2994 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2995 * @n_rx: size of rxbuf, in bytes
33e34dc6 2996 * Context: can sleep
8ae12a0d
DB		 2997 *
2998 * This performs a half duplex MicroWire style transaction with the
2999 * device, sending txbuf and then reading rxbuf. The return value
3000 * is zero for success, else a negative errno status code.
b885244e 3001 * This call may only be used from a context that may sleep.
8ae12a0d 3002 *
0c868461 3003 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 3004 * portable code should never use this for more than 32 bytes.
3005 * Performance-sensitive or bulk transfer code should instead use
0c868461 3006 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 3007 *
3008 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 3009 */
3010int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 3011 const void *txbuf, unsigned n_tx,
3012 void *rxbuf, unsigned n_rx)
8ae12a0d 3013{
068f4070 3014 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 3015
3016 int status;
3017 struct spi_message message;
bdff549e 3018 struct spi_transfer x[2];
8ae12a0d
DB		 3019 u8 *local_buf;
3020
b3a223ee
MB		 3021 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3022 * copying here, (as a pure convenience thing), but we can
3023 * keep heap costs out of the hot path unless someone else is
3024 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 3025 */
b3a223ee 3026 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 3027 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3028 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 3029 if (!local_buf)
3030 return -ENOMEM;
3031 } else {
3032 local_buf = buf;
3033 }
8ae12a0d 3034
8275c642 3035 spi_message_init(&message);
5fe5f05e 3036 memset(x, 0, sizeof(x));
bdff549e
DB		 3037 if (n_tx) {
3038 x[0].len = n_tx;
3039 spi_message_add_tail(&x[0], &message);
3040 }
3041 if (n_rx) {
3042 x[1].len = n_rx;
3043 spi_message_add_tail(&x[1], &message);
3044 }
8275c642 3045
8ae12a0d 3046 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 3047 x[0].tx_buf = local_buf;
3048 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 3049
3050 /* do the i/o */
8ae12a0d 3051 status = spi_sync(spi, &message);
9b938b74 3052 if (status == 0)
bdff549e 3053 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 3054
bdff549e 3055 if (x[0].tx_buf == buf)
068f4070 3056 mutex_unlock(&lock);
8ae12a0d
DB		 3057 else
3058 kfree(local_buf);
3059
3060 return status;
3061}
3062EXPORT_SYMBOL_GPL(spi_write_then_read);
3063
3064/*-------------------------------------------------------------------------*/
3065
ce79d54a
PA		 3066#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3067static int __spi_of_device_match(struct device *dev, void *data)
3068{
3069 return dev->of_node == data;
3070}
3071
3072/* must call put_device() when done with returned spi_device device */
3073static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3074{
3075 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3076 __spi_of_device_match);
3077 return dev ? to_spi_device(dev) : NULL;
3078}
3079
3080static int __spi_of_master_match(struct device *dev, const void *data)
3081{
3082 return dev->of_node == data;
3083}
3084
3085/* the spi masters are not using spi_bus, so we find it with another way */
3086static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3087{
3088 struct device *dev;
3089
3090 dev = class_find_device(&spi_master_class, NULL, node,
3091 __spi_of_master_match);
3092 if (!dev)
3093 return NULL;
3094
3095 /* reference got in class_find_device */
3096 return container_of(dev, struct spi_master, dev);
3097}
3098
3099static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3100 void *arg)
3101{
3102 struct of_reconfig_data *rd = arg;
3103 struct spi_master *master;
3104 struct spi_device *spi;
3105
3106 switch (of_reconfig_get_state_change(action, arg)) {
3107 case OF_RECONFIG_CHANGE_ADD:
3108 master = of_find_spi_master_by_node(rd->dn->parent);
3109 if (master == NULL)
3110 return NOTIFY_OK; /* not for us */
3111
bd6c1644
GU		 3112 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3113 put_device(&master->dev);
3114 return NOTIFY_OK;
3115 }
3116
ce79d54a
PA		 3117 spi = of_register_spi_device(master, rd->dn);
3118 put_device(&master->dev);
3119
3120 if (IS_ERR(spi)) {
3121 pr_err("%s: failed to create for '%s'\n",
3122 __func__, rd->dn->full_name);
3123 return notifier_from_errno(PTR_ERR(spi));
3124 }
3125 break;
3126
3127 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3128 /* already depopulated? */
3129 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3130 return NOTIFY_OK;
3131
ce79d54a
PA		 3132 /* find our device by node */
3133 spi = of_find_spi_device_by_node(rd->dn);
3134 if (spi == NULL)
3135 return NOTIFY_OK; /* no? not meant for us */
3136
3137 /* unregister takes one ref away */
3138 spi_unregister_device(spi);
3139
3140 /* and put the reference of the find */
3141 put_device(&spi->dev);
3142 break;
3143 }
3144
3145 return NOTIFY_OK;
3146}
3147
3148static struct notifier_block spi_of_notifier = {
3149 .notifier_call = of_spi_notify,
3150};
3151#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3152extern struct notifier_block spi_of_notifier;
3153#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3154
7f24467f
OP		 3155#if IS_ENABLED(CONFIG_ACPI)
3156static int spi_acpi_master_match(struct device *dev, const void *data)
3157{
3158 return ACPI_COMPANION(dev->parent) == data;
3159}
3160
3161static int spi_acpi_device_match(struct device *dev, void *data)
3162{
3163 return ACPI_COMPANION(dev) == data;
3164}
3165
3166static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3167{
3168 struct device *dev;
3169
3170 dev = class_find_device(&spi_master_class, NULL, adev,
3171 spi_acpi_master_match);
3172 if (!dev)
3173 return NULL;
3174
3175 return container_of(dev, struct spi_master, dev);
3176}
3177
3178static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3179{
3180 struct device *dev;
3181
3182 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3183
3184 return dev ? to_spi_device(dev) : NULL;
3185}
3186
3187static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3188 void *arg)
3189{
3190 struct acpi_device *adev = arg;
3191 struct spi_master *master;
3192 struct spi_device *spi;
3193
3194 switch (value) {
3195 case ACPI_RECONFIG_DEVICE_ADD:
3196 master = acpi_spi_find_master_by_adev(adev->parent);
3197 if (!master)
3198 break;
3199
3200 acpi_register_spi_device(master, adev);
3201 put_device(&master->dev);
3202 break;
3203 case ACPI_RECONFIG_DEVICE_REMOVE:
3204 if (!acpi_device_enumerated(adev))
3205 break;
3206
3207 spi = acpi_spi_find_device_by_adev(adev);
3208 if (!spi)
3209 break;
3210
3211 spi_unregister_device(spi);
3212 put_device(&spi->dev);
3213 break;
3214 }
3215
3216 return NOTIFY_OK;
3217}
3218
3219static struct notifier_block spi_acpi_notifier = {
3220 .notifier_call = acpi_spi_notify,
3221};
3222#else
3223extern struct notifier_block spi_acpi_notifier;
3224#endif
3225
8ae12a0d
DB		 3226static int __init spi_init(void)
3227{
b885244e
DB		 3228 int status;
3229
e94b1766 3230 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3231 if (!buf) {
3232 status = -ENOMEM;
3233 goto err0;
3234 }
3235
3236 status = bus_register(&spi_bus_type);
3237 if (status < 0)
3238 goto err1;
8ae12a0d 3239
b885244e
DB		 3240 status = class_register(&spi_master_class);
3241 if (status < 0)
3242 goto err2;
ce79d54a 3243
5267720e 3244 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a 3245 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
7f24467f
OP		 3246 if (IS_ENABLED(CONFIG_ACPI))
3247 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
ce79d54a 3248
8ae12a0d 3249 return 0;
b885244e
DB		 3250
3251err2:
3252 bus_unregister(&spi_bus_type);
3253err1:
3254 kfree(buf);
3255 buf = NULL;
3256err0:
3257 return status;
8ae12a0d 3258}
b885244e 3259
8ae12a0d
DB		 3260/* board_info is normally registered in arch_initcall(),
3261 * but even essential drivers wait till later
b885244e
DB		 3262 *
3263 * REVISIT only boardinfo really needs static linking. the rest (device and
3264 * driver registration) _could_ be dynamically linked (modular) ... costs
3265 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3266 */
673c0c00 3267postcore_initcall(spi_init);
8ae12a0d 3268
Linux kernel - Deliverables
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