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ACPI / property: Allow holes in reference properties
[linux-2.6-block.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;
682a71b2 963 unsigned 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;
994 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
995 ms += ms + 100; /* some tolerance */
16a0ce4e 996
38ec10f6
MB		 997 ms = wait_for_completion_timeout(&master->xfer_completion,
998 msecs_to_jiffies(ms));
999 }
16a0ce4e 1000
38ec10f6 1001 if (ms == 0) {
eca2ebc7
MS		 1002 SPI_STATISTICS_INCREMENT_FIELD(statm,
1003 timedout);
1004 SPI_STATISTICS_INCREMENT_FIELD(stats,
1005 timedout);
38ec10f6
MB		 1006 dev_err(&msg->spi->dev,
1007 "SPI transfer timed out\n");
1008 msg->status = -ETIMEDOUT;
1009 }
1010 } else {
1011 if (xfer->len)
1012 dev_err(&msg->spi->dev,
1013 "Bufferless transfer has length %u\n",
1014 xfer->len);
13a42798 1015 }
b158935f
MB		 1016
1017 trace_spi_transfer_stop(msg, xfer);
1018
1019 if (msg->status != -EINPROGRESS)
1020 goto out;
1021
1022 if (xfer->delay_usecs)
1023 udelay(xfer->delay_usecs);
1024
1025 if (xfer->cs_change) {
1026 if (list_is_last(&xfer->transfer_list,
1027 &msg->transfers)) {
1028 keep_cs = true;
1029 } else {
0b73aa63
MB		 1030 spi_set_cs(msg->spi, false);
1031 udelay(10);
1032 spi_set_cs(msg->spi, true);
b158935f
MB		 1033 }
1034 }
1035
1036 msg->actual_length += xfer->len;
1037 }
1038
1039out:
1040 if (ret != 0 || !keep_cs)
1041 spi_set_cs(msg->spi, false);
1042
1043 if (msg->status == -EINPROGRESS)
1044 msg->status = ret;
1045
ff61eb42 1046 if (msg->status && master->handle_err)
b716c4ff
AS		 1047 master->handle_err(master, msg);
1048
d780c371
MS		 1049 spi_res_release(master, msg);
1050
b158935f
MB		 1051 spi_finalize_current_message(master);
1052
1053 return ret;
1054}
1055
1056/**
1057 * spi_finalize_current_transfer - report completion of a transfer
2c675689 1058 * @master: the master reporting completion
b158935f
MB		 1059 *
1060 * Called by SPI drivers using the core transfer_one_message()
1061 * implementation to notify it that the current interrupt driven
9e8f4882 1062 * transfer has finished and the next one may be scheduled.
b158935f
MB		 1063 */
1064void spi_finalize_current_transfer(struct spi_master *master)
1065{
1066 complete(&master->xfer_completion);
1067}
1068EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1069
ffbbdd21 1070/**
fc9e0f71
MB		 1071 * __spi_pump_messages - function which processes spi message queue
1072 * @master: master to process queue for
1073 * @in_kthread: true if we are in the context of the message pump thread
ffbbdd21
LW		 1074 *
1075 * This function checks if there is any spi message in the queue that
1076 * needs processing and if so call out to the driver to initialize hardware
1077 * and transfer each message.
1078 *
0461a414
MB		 1079 * Note that it is called both from the kthread itself and also from
1080 * inside spi_sync(); the queue extraction handling at the top of the
1081 * function should deal with this safely.
ffbbdd21 1082 */
ef4d96ec 1083static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
ffbbdd21 1084{
ffbbdd21
LW		 1085 unsigned long flags;
1086 bool was_busy = false;
1087 int ret;
1088
983aee5d 1089 /* Lock queue */
ffbbdd21 1090 spin_lock_irqsave(&master->queue_lock, flags);
983aee5d
MB		 1091
1092 /* Make sure we are not already running a message */
1093 if (master->cur_msg) {
1094 spin_unlock_irqrestore(&master->queue_lock, flags);
1095 return;
1096 }
1097
0461a414
MB		 1098 /* If another context is idling the device then defer */
1099 if (master->idling) {
1100 queue_kthread_work(&master->kworker, &master->pump_messages);
1101 spin_unlock_irqrestore(&master->queue_lock, flags);
1102 return;
1103 }
1104
983aee5d 1105 /* Check if the queue is idle */
ffbbdd21 1106 if (list_empty(&master->queue) || !master->running) {
b0b36b86
BF		 1107 if (!master->busy) {
1108 spin_unlock_irqrestore(&master->queue_lock, flags);
1109 return;
ffbbdd21 1110 }
fc9e0f71
MB		 1111
1112 /* Only do teardown in the thread */
1113 if (!in_kthread) {
1114 queue_kthread_work(&master->kworker,
1115 &master->pump_messages);
1116 spin_unlock_irqrestore(&master->queue_lock, flags);
1117 return;
1118 }
1119
ffbbdd21 1120 master->busy = false;
0461a414 1121 master->idling = true;
ffbbdd21 1122 spin_unlock_irqrestore(&master->queue_lock, flags);
0461a414 1123
3a2eba9b
MB		 1124 kfree(master->dummy_rx);
1125 master->dummy_rx = NULL;
1126 kfree(master->dummy_tx);
1127 master->dummy_tx = NULL;
b0b36b86
BF		 1128 if (master->unprepare_transfer_hardware &&
1129 master->unprepare_transfer_hardware(master))
1130 dev_err(&master->dev,
1131 "failed to unprepare transfer hardware\n");
49834de2
MB		 1132 if (master->auto_runtime_pm) {
1133 pm_runtime_mark_last_busy(master->dev.parent);
1134 pm_runtime_put_autosuspend(master->dev.parent);
1135 }
56ec1978 1136 trace_spi_master_idle(master);
ffbbdd21 1137
0461a414
MB		 1138 spin_lock_irqsave(&master->queue_lock, flags);
1139 master->idling = false;
ffbbdd21
LW		 1140 spin_unlock_irqrestore(&master->queue_lock, flags);
1141 return;
1142 }
ffbbdd21 1143
ffbbdd21
LW		 1144 /* Extract head of queue */
1145 master->cur_msg =
a89e2d27 1146 list_first_entry(&master->queue, struct spi_message, queue);
ffbbdd21
LW		 1147
1148 list_del_init(&master->cur_msg->queue);
1149 if (master->busy)
1150 was_busy = true;
1151 else
1152 master->busy = true;
1153 spin_unlock_irqrestore(&master->queue_lock, flags);
1154
ef4d96ec
MB		 1155 mutex_lock(&master->io_mutex);
1156
49834de2
MB		 1157 if (!was_busy && master->auto_runtime_pm) {
1158 ret = pm_runtime_get_sync(master->dev.parent);
1159 if (ret < 0) {
1160 dev_err(&master->dev, "Failed to power device: %d\n",
1161 ret);
1162 return;
1163 }
1164 }
1165
56ec1978
MB		 1166 if (!was_busy)
1167 trace_spi_master_busy(master);
1168
7dfd2bd7 1169 if (!was_busy && master->prepare_transfer_hardware) {
ffbbdd21
LW		 1170 ret = master->prepare_transfer_hardware(master);
1171 if (ret) {
1172 dev_err(&master->dev,
1173 "failed to prepare transfer hardware\n");
49834de2
MB		 1174
1175 if (master->auto_runtime_pm)
1176 pm_runtime_put(master->dev.parent);
ffbbdd21
LW		 1177 return;
1178 }
1179 }
1180
56ec1978
MB		 1181 trace_spi_message_start(master->cur_msg);
1182
2841a5fc
MB		 1183 if (master->prepare_message) {
1184 ret = master->prepare_message(master, master->cur_msg);
1185 if (ret) {
1186 dev_err(&master->dev,
1187 "failed to prepare message: %d\n", ret);
1188 master->cur_msg->status = ret;
1189 spi_finalize_current_message(master);
49023d2e 1190 goto out;
2841a5fc
MB		 1191 }
1192 master->cur_msg_prepared = true;
1193 }
1194
99adef31
MB		 1195 ret = spi_map_msg(master, master->cur_msg);
1196 if (ret) {
1197 master->cur_msg->status = ret;
1198 spi_finalize_current_message(master);
49023d2e 1199 goto out;
99adef31
MB		 1200 }
1201
ffbbdd21
LW		 1202 ret = master->transfer_one_message(master, master->cur_msg);
1203 if (ret) {
1204 dev_err(&master->dev,
1f802f82 1205 "failed to transfer one message from queue\n");
49023d2e 1206 goto out;
ffbbdd21 1207 }
49023d2e
JH		 1208
1209out:
ef4d96ec 1210 mutex_unlock(&master->io_mutex);
62826970
MB		 1211
1212 /* Prod the scheduler in case transfer_one() was busy waiting */
49023d2e
JH		 1213 if (!ret)
1214 cond_resched();
ffbbdd21
LW		 1215}
1216
fc9e0f71
MB		 1217/**
1218 * spi_pump_messages - kthread work function which processes spi message queue
1219 * @work: pointer to kthread work struct contained in the master struct
1220 */
1221static void spi_pump_messages(struct kthread_work *work)
1222{
1223 struct spi_master *master =
1224 container_of(work, struct spi_master, pump_messages);
1225
ef4d96ec 1226 __spi_pump_messages(master, true);
fc9e0f71
MB		 1227}
1228
ffbbdd21
LW		 1229static int spi_init_queue(struct spi_master *master)
1230{
1231 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1232
ffbbdd21
LW		 1233 master->running = false;
1234 master->busy = false;
1235
1236 init_kthread_worker(&master->kworker);
1237 master->kworker_task = kthread_run(kthread_worker_fn,
f170168b 1238 &master->kworker, "%s",
ffbbdd21
LW		 1239 dev_name(&master->dev));
1240 if (IS_ERR(master->kworker_task)) {
1241 dev_err(&master->dev, "failed to create message pump task\n");
98a8f5a0 1242 return PTR_ERR(master->kworker_task);
ffbbdd21
LW		 1243 }
1244 init_kthread_work(&master->pump_messages, spi_pump_messages);
1245
1246 /*
1247 * Master config will indicate if this controller should run the
1248 * message pump with high (realtime) priority to reduce the transfer
1249 * latency on the bus by minimising the delay between a transfer
1250 * request and the scheduling of the message pump thread. Without this
1251 * setting the message pump thread will remain at default priority.
1252 */
1253 if (master->rt) {
1254 dev_info(&master->dev,
1255 "will run message pump with realtime priority\n");
1256 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1257 }
1258
1259 return 0;
1260}
1261
1262/**
1263 * spi_get_next_queued_message() - called by driver to check for queued
1264 * messages
1265 * @master: the master to check for queued messages
1266 *
1267 * If there are more messages in the queue, the next message is returned from
1268 * this call.
97d56dc6
JMC		 1269 *
1270 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21
LW		 1271 */
1272struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1273{
1274 struct spi_message *next;
1275 unsigned long flags;
1276
1277 /* get a pointer to the next message, if any */
1278 spin_lock_irqsave(&master->queue_lock, flags);
1cfd97f9
AL		 1279 next = list_first_entry_or_null(&master->queue, struct spi_message,
1280 queue);
ffbbdd21
LW		 1281 spin_unlock_irqrestore(&master->queue_lock, flags);
1282
1283 return next;
1284}
1285EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1286
1287/**
1288 * spi_finalize_current_message() - the current message is complete
1289 * @master: the master to return the message to
1290 *
1291 * Called by the driver to notify the core that the message in the front of the
1292 * queue is complete and can be removed from the queue.
1293 */
1294void spi_finalize_current_message(struct spi_master *master)
1295{
1296 struct spi_message *mesg;
1297 unsigned long flags;
2841a5fc 1298 int ret;
ffbbdd21
LW		 1299
1300 spin_lock_irqsave(&master->queue_lock, flags);
1301 mesg = master->cur_msg;
ffbbdd21
LW		 1302 spin_unlock_irqrestore(&master->queue_lock, flags);
1303
99adef31
MB		 1304 spi_unmap_msg(master, mesg);
1305
2841a5fc
MB		 1306 if (master->cur_msg_prepared && master->unprepare_message) {
1307 ret = master->unprepare_message(master, mesg);
1308 if (ret) {
1309 dev_err(&master->dev,
1310 "failed to unprepare message: %d\n", ret);
1311 }
1312 }
391949b6 1313
8e76ef88
MS		 1314 spin_lock_irqsave(&master->queue_lock, flags);
1315 master->cur_msg = NULL;
2841a5fc 1316 master->cur_msg_prepared = false;
8e76ef88
MS		 1317 queue_kthread_work(&master->kworker, &master->pump_messages);
1318 spin_unlock_irqrestore(&master->queue_lock, flags);
1319
1320 trace_spi_message_done(mesg);
2841a5fc 1321
ffbbdd21
LW		 1322 mesg->state = NULL;
1323 if (mesg->complete)
1324 mesg->complete(mesg->context);
1325}
1326EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1327
1328static int spi_start_queue(struct spi_master *master)
1329{
1330 unsigned long flags;
1331
1332 spin_lock_irqsave(&master->queue_lock, flags);
1333
1334 if (master->running || master->busy) {
1335 spin_unlock_irqrestore(&master->queue_lock, flags);
1336 return -EBUSY;
1337 }
1338
1339 master->running = true;
1340 master->cur_msg = NULL;
1341 spin_unlock_irqrestore(&master->queue_lock, flags);
1342
1343 queue_kthread_work(&master->kworker, &master->pump_messages);
1344
1345 return 0;
1346}
1347
1348static int spi_stop_queue(struct spi_master *master)
1349{
1350 unsigned long flags;
1351 unsigned limit = 500;
1352 int ret = 0;
1353
1354 spin_lock_irqsave(&master->queue_lock, flags);
1355
1356 /*
1357 * This is a bit lame, but is optimized for the common execution path.
1358 * A wait_queue on the master->busy could be used, but then the common
1359 * execution path (pump_messages) would be required to call wake_up or
1360 * friends on every SPI message. Do this instead.
1361 */
1362 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1363 spin_unlock_irqrestore(&master->queue_lock, flags);
f97b26b0 1364 usleep_range(10000, 11000);
ffbbdd21
LW		 1365 spin_lock_irqsave(&master->queue_lock, flags);
1366 }
1367
1368 if (!list_empty(&master->queue) || master->busy)
1369 ret = -EBUSY;
1370 else
1371 master->running = false;
1372
1373 spin_unlock_irqrestore(&master->queue_lock, flags);
1374
1375 if (ret) {
1376 dev_warn(&master->dev,
1377 "could not stop message queue\n");
1378 return ret;
1379 }
1380 return ret;
1381}
1382
1383static int spi_destroy_queue(struct spi_master *master)
1384{
1385 int ret;
1386
1387 ret = spi_stop_queue(master);
1388
1389 /*
1390 * flush_kthread_worker will block until all work is done.
1391 * If the reason that stop_queue timed out is that the work will never
1392 * finish, then it does no good to call flush/stop thread, so
1393 * return anyway.
1394 */
1395 if (ret) {
1396 dev_err(&master->dev, "problem destroying queue\n");
1397 return ret;
1398 }
1399
1400 flush_kthread_worker(&master->kworker);
1401 kthread_stop(master->kworker_task);
1402
1403 return 0;
1404}
1405
0461a414
MB		 1406static int __spi_queued_transfer(struct spi_device *spi,
1407 struct spi_message *msg,
1408 bool need_pump)
ffbbdd21
LW		 1409{
1410 struct spi_master *master = spi->master;
1411 unsigned long flags;
1412
1413 spin_lock_irqsave(&master->queue_lock, flags);
1414
1415 if (!master->running) {
1416 spin_unlock_irqrestore(&master->queue_lock, flags);
1417 return -ESHUTDOWN;
1418 }
1419 msg->actual_length = 0;
1420 msg->status = -EINPROGRESS;
1421
1422 list_add_tail(&msg->queue, &master->queue);
0461a414 1423 if (!master->busy && need_pump)
ffbbdd21
LW		 1424 queue_kthread_work(&master->kworker, &master->pump_messages);
1425
1426 spin_unlock_irqrestore(&master->queue_lock, flags);
1427 return 0;
1428}
1429
0461a414
MB		 1430/**
1431 * spi_queued_transfer - transfer function for queued transfers
1432 * @spi: spi device which is requesting transfer
1433 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1434 *
1435 * Return: zero on success, else a negative error code.
0461a414
MB		 1436 */
1437static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1438{
1439 return __spi_queued_transfer(spi, msg, true);
1440}
1441
ffbbdd21
LW		 1442static int spi_master_initialize_queue(struct spi_master *master)
1443{
1444 int ret;
1445
ffbbdd21 1446 master->transfer = spi_queued_transfer;
b158935f
MB		 1447 if (!master->transfer_one_message)
1448 master->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1449
1450 /* Initialize and start queue */
1451 ret = spi_init_queue(master);
1452 if (ret) {
1453 dev_err(&master->dev, "problem initializing queue\n");
1454 goto err_init_queue;
1455 }
c3676d5c 1456 master->queued = true;
ffbbdd21
LW		 1457 ret = spi_start_queue(master);
1458 if (ret) {
1459 dev_err(&master->dev, "problem starting queue\n");
1460 goto err_start_queue;
1461 }
1462
1463 return 0;
1464
1465err_start_queue:
ffbbdd21 1466 spi_destroy_queue(master);
c3676d5c 1467err_init_queue:
ffbbdd21
LW		 1468 return ret;
1469}
1470
1471/*-------------------------------------------------------------------------*/
1472
7cb94361 1473#if defined(CONFIG_OF)
aff5e3f8
PA		 1474static struct spi_device *
1475of_register_spi_device(struct spi_master *master, struct device_node *nc)
1476{
1477 struct spi_device *spi;
1478 int rc;
1479 u32 value;
1480
1481 /* Alloc an spi_device */
1482 spi = spi_alloc_device(master);
1483 if (!spi) {
1484 dev_err(&master->dev, "spi_device alloc error for %s\n",
1485 nc->full_name);
1486 rc = -ENOMEM;
1487 goto err_out;
1488 }
1489
1490 /* Select device driver */
1491 rc = of_modalias_node(nc, spi->modalias,
1492 sizeof(spi->modalias));
1493 if (rc < 0) {
1494 dev_err(&master->dev, "cannot find modalias for %s\n",
1495 nc->full_name);
1496 goto err_out;
1497 }
1498
1499 /* Device address */
1500 rc = of_property_read_u32(nc, "reg", &value);
1501 if (rc) {
1502 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1503 nc->full_name, rc);
1504 goto err_out;
1505 }
1506 spi->chip_select = value;
1507
1508 /* Mode (clock phase/polarity/etc.) */
1509 if (of_find_property(nc, "spi-cpha", NULL))
1510 spi->mode |= SPI_CPHA;
1511 if (of_find_property(nc, "spi-cpol", NULL))
1512 spi->mode |= SPI_CPOL;
1513 if (of_find_property(nc, "spi-cs-high", NULL))
1514 spi->mode |= SPI_CS_HIGH;
1515 if (of_find_property(nc, "spi-3wire", NULL))
1516 spi->mode |= SPI_3WIRE;
1517 if (of_find_property(nc, "spi-lsb-first", NULL))
1518 spi->mode |= SPI_LSB_FIRST;
1519
1520 /* Device DUAL/QUAD mode */
1521 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1522 switch (value) {
1523 case 1:
1524 break;
1525 case 2:
1526 spi->mode |= SPI_TX_DUAL;
1527 break;
1528 case 4:
1529 spi->mode |= SPI_TX_QUAD;
1530 break;
1531 default:
1532 dev_warn(&master->dev,
1533 "spi-tx-bus-width %d not supported\n",
1534 value);
1535 break;
1536 }
1537 }
1538
1539 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1540 switch (value) {
1541 case 1:
1542 break;
1543 case 2:
1544 spi->mode |= SPI_RX_DUAL;
1545 break;
1546 case 4:
1547 spi->mode |= SPI_RX_QUAD;
1548 break;
1549 default:
1550 dev_warn(&master->dev,
1551 "spi-rx-bus-width %d not supported\n",
1552 value);
1553 break;
1554 }
1555 }
1556
1557 /* Device speed */
1558 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1559 if (rc) {
1560 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1561 nc->full_name, rc);
1562 goto err_out;
1563 }
1564 spi->max_speed_hz = value;
1565
aff5e3f8
PA		 1566 /* Store a pointer to the node in the device structure */
1567 of_node_get(nc);
1568 spi->dev.of_node = nc;
1569
1570 /* Register the new device */
aff5e3f8
PA		 1571 rc = spi_add_device(spi);
1572 if (rc) {
1573 dev_err(&master->dev, "spi_device register error %s\n",
1574 nc->full_name);
1575 goto err_out;
1576 }
1577
1578 return spi;
1579
1580err_out:
1581 spi_dev_put(spi);
1582 return ERR_PTR(rc);
1583}
1584
d57a4282
GL		 1585/**
1586 * of_register_spi_devices() - Register child devices onto the SPI bus
1587 * @master: Pointer to spi_master device
1588 *
1589 * Registers an spi_device for each child node of master node which has a 'reg'
1590 * property.
1591 */
1592static void of_register_spi_devices(struct spi_master *master)
1593{
1594 struct spi_device *spi;
1595 struct device_node *nc;
d57a4282
GL		 1596
1597 if (!master->dev.of_node)
1598 return;
1599
f3b6159e 1600 for_each_available_child_of_node(master->dev.of_node, nc) {
bd6c1644
GU		 1601 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1602 continue;
aff5e3f8
PA		 1603 spi = of_register_spi_device(master, nc);
1604 if (IS_ERR(spi))
1605 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
d57a4282 1606 nc->full_name);
d57a4282
GL		 1607 }
1608}
1609#else
1610static void of_register_spi_devices(struct spi_master *master) { }
1611#endif
1612
64bee4d2
MW		 1613#ifdef CONFIG_ACPI
1614static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1615{
1616 struct spi_device *spi = data;
a0a90718 1617 struct spi_master *master = spi->master;
64bee4d2
MW		 1618
1619 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1620 struct acpi_resource_spi_serialbus *sb;
1621
1622 sb = &ares->data.spi_serial_bus;
1623 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
a0a90718
MW		 1624 /*
1625 * ACPI DeviceSelection numbering is handled by the
1626 * host controller driver in Windows and can vary
1627 * from driver to driver. In Linux we always expect
1628 * 0 .. max - 1 so we need to ask the driver to
1629 * translate between the two schemes.
1630 */
1631 if (master->fw_translate_cs) {
1632 int cs = master->fw_translate_cs(master,
1633 sb->device_selection);
1634 if (cs < 0)
1635 return cs;
1636 spi->chip_select = cs;
1637 } else {
1638 spi->chip_select = sb->device_selection;
1639 }
1640
64bee4d2
MW		 1641 spi->max_speed_hz = sb->connection_speed;
1642
1643 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1644 spi->mode |= SPI_CPHA;
1645 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1646 spi->mode |= SPI_CPOL;
1647 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1648 spi->mode |= SPI_CS_HIGH;
1649 }
1650 } else if (spi->irq < 0) {
1651 struct resource r;
1652
1653 if (acpi_dev_resource_interrupt(ares, 0, &r))
1654 spi->irq = r.start;
1655 }
1656
1657 /* Always tell the ACPI core to skip this resource */
1658 return 1;
1659}
1660
7f24467f
OP		 1661static acpi_status acpi_register_spi_device(struct spi_master *master,
1662 struct acpi_device *adev)
64bee4d2 1663{
64bee4d2 1664 struct list_head resource_list;
64bee4d2
MW		 1665 struct spi_device *spi;
1666 int ret;
1667
7f24467f
OP		 1668 if (acpi_bus_get_status(adev) || !adev->status.present ||
1669 acpi_device_enumerated(adev))
64bee4d2
MW		 1670 return AE_OK;
1671
1672 spi = spi_alloc_device(master);
1673 if (!spi) {
1674 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1675 dev_name(&adev->dev));
1676 return AE_NO_MEMORY;
1677 }
1678
7b199811 1679 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1680 spi->irq = -1;
1681
1682 INIT_LIST_HEAD(&resource_list);
1683 ret = acpi_dev_get_resources(adev, &resource_list,
1684 acpi_spi_add_resource, spi);
1685 acpi_dev_free_resource_list(&resource_list);
1686
1687 if (ret < 0 || !spi->max_speed_hz) {
1688 spi_dev_put(spi);
1689 return AE_OK;
1690 }
1691
33ada67d
CR		 1692 if (spi->irq < 0)
1693 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1694
7f24467f
OP		 1695 acpi_device_set_enumerated(adev);
1696
33cf00e5 1697 adev->power.flags.ignore_parent = true;
cf9eb39c 1698 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
64bee4d2 1699 if (spi_add_device(spi)) {
33cf00e5 1700 adev->power.flags.ignore_parent = false;
64bee4d2
MW		 1701 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1702 dev_name(&adev->dev));
1703 spi_dev_put(spi);
1704 }
1705
1706 return AE_OK;
1707}
1708
7f24467f
OP		 1709static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1710 void *data, void **return_value)
1711{
1712 struct spi_master *master = data;
1713 struct acpi_device *adev;
1714
1715 if (acpi_bus_get_device(handle, &adev))
1716 return AE_OK;
1717
1718 return acpi_register_spi_device(master, adev);
1719}
1720
64bee4d2
MW		 1721static void acpi_register_spi_devices(struct spi_master *master)
1722{
1723 acpi_status status;
1724 acpi_handle handle;
1725
29896178 1726 handle = ACPI_HANDLE(master->dev.parent);
64bee4d2
MW		 1727 if (!handle)
1728 return;
1729
1730 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1731 acpi_spi_add_device, NULL,
1732 master, NULL);
1733 if (ACPI_FAILURE(status))
1734 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1735}
1736#else
1737static inline void acpi_register_spi_devices(struct spi_master *master) {}
1738#endif /* CONFIG_ACPI */
1739
49dce689 1740static void spi_master_release(struct device *dev)
8ae12a0d
DB		 1741{
1742 struct spi_master *master;
1743
49dce689 1744 master = container_of(dev, struct spi_master, dev);
8ae12a0d
DB		 1745 kfree(master);
1746}
1747
1748static struct class spi_master_class = {
1749 .name = "spi_master",
1750 .owner = THIS_MODULE,
49dce689 1751 .dev_release = spi_master_release,
eca2ebc7 1752 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1753};
1754
1755
1756/**
1757 * spi_alloc_master - allocate SPI master controller
1758 * @dev: the controller, possibly using the platform_bus
33e34dc6 1759 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 1760 * memory is in the driver_data field of the returned device,
0c868461 1761 * accessible with spi_master_get_devdata().
33e34dc6 1762 * Context: can sleep
8ae12a0d
DB		 1763 *
1764 * This call is used only by SPI master controller drivers, which are the
1765 * only ones directly touching chip registers. It's how they allocate
ba1a0513 1766 * an spi_master structure, prior to calling spi_register_master().
8ae12a0d 1767 *
97d56dc6 1768 * This must be called from context that can sleep.
8ae12a0d
DB		 1769 *
1770 * The caller is responsible for assigning the bus number and initializing
ba1a0513 1771 * the master's methods before calling spi_register_master(); and (after errors
a394d635 1772 * adding the device) calling spi_master_put() to prevent a memory leak.
97d56dc6
JMC		 1773 *
1774 * Return: the SPI master structure on success, else NULL.
8ae12a0d 1775 */
e9d5a461 1776struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
8ae12a0d
DB		 1777{
1778 struct spi_master *master;
1779
0c868461
DB		 1780 if (!dev)
1781 return NULL;
1782
5fe5f05e 1783 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
8ae12a0d
DB		 1784 if (!master)
1785 return NULL;
1786
49dce689 1787 device_initialize(&master->dev);
1e8a52e1
GL		 1788 master->bus_num = -1;
1789 master->num_chipselect = 1;
49dce689 1790 master->dev.class = &spi_master_class;
157f38f9 1791 master->dev.parent = dev;
d7e2ee25 1792 pm_suspend_ignore_children(&master->dev, true);
0c868461 1793 spi_master_set_devdata(master, &master[1]);
8ae12a0d
DB		 1794
1795 return master;
1796}
1797EXPORT_SYMBOL_GPL(spi_alloc_master);
1798
74317984
JCPV		 1799#ifdef CONFIG_OF
1800static int of_spi_register_master(struct spi_master *master)
1801{
e80beb27 1802 int nb, i, *cs;
74317984
JCPV		 1803 struct device_node *np = master->dev.of_node;
1804
1805 if (!np)
1806 return 0;
1807
1808 nb = of_gpio_named_count(np, "cs-gpios");
5fe5f05e 1809 master->num_chipselect = max_t(int, nb, master->num_chipselect);
74317984 1810
8ec5d84e
AL		 1811 /* Return error only for an incorrectly formed cs-gpios property */
1812 if (nb == 0 || nb == -ENOENT)
74317984 1813 return 0;
8ec5d84e
AL		 1814 else if (nb < 0)
1815 return nb;
74317984
JCPV		 1816
1817 cs = devm_kzalloc(&master->dev,
1818 sizeof(int) * master->num_chipselect,
1819 GFP_KERNEL);
1820 master->cs_gpios = cs;
1821
1822 if (!master->cs_gpios)
1823 return -ENOMEM;
1824
0da83bb1 1825 for (i = 0; i < master->num_chipselect; i++)
446411e1 1826 cs[i] = -ENOENT;
74317984
JCPV		 1827
1828 for (i = 0; i < nb; i++)
1829 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1830
1831 return 0;
1832}
1833#else
1834static int of_spi_register_master(struct spi_master *master)
1835{
1836 return 0;
1837}
1838#endif
1839
8ae12a0d
DB		 1840/**
1841 * spi_register_master - register SPI master controller
1842 * @master: initialized master, originally from spi_alloc_master()
33e34dc6 1843 * Context: can sleep
8ae12a0d
DB		 1844 *
1845 * SPI master controllers connect to their drivers using some non-SPI bus,
1846 * such as the platform bus. The final stage of probe() in that code
1847 * includes calling spi_register_master() to hook up to this SPI bus glue.
1848 *
1849 * SPI controllers use board specific (often SOC specific) bus numbers,
1850 * and board-specific addressing for SPI devices combines those numbers
1851 * with chip select numbers. Since SPI does not directly support dynamic
1852 * device identification, boards need configuration tables telling which
1853 * chip is at which address.
1854 *
1855 * This must be called from context that can sleep. It returns zero on
1856 * success, else a negative error code (dropping the master's refcount).
0c868461
DB		 1857 * After a successful return, the caller is responsible for calling
1858 * spi_unregister_master().
97d56dc6
JMC		 1859 *
1860 * Return: zero on success, else a negative error code.
8ae12a0d 1861 */
e9d5a461 1862int spi_register_master(struct spi_master *master)
8ae12a0d 1863{
e44a45ae 1864 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
49dce689 1865 struct device *dev = master->dev.parent;
2b9603a0 1866 struct boardinfo *bi;
8ae12a0d
DB		 1867 int status = -ENODEV;
1868 int dynamic = 0;
1869
0c868461
DB		 1870 if (!dev)
1871 return -ENODEV;
1872
74317984
JCPV		 1873 status = of_spi_register_master(master);
1874 if (status)
1875 return status;
1876
082c8cb4
DB		 1877 /* even if it's just one always-selected device, there must
1878 * be at least one chipselect
1879 */
1880 if (master->num_chipselect == 0)
1881 return -EINVAL;
1882
bb29785e
GL		 1883 if ((master->bus_num < 0) && master->dev.of_node)
1884 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1885
8ae12a0d 1886 /* convention: dynamically assigned bus IDs count down from the max */
a020ed75 1887 if (master->bus_num < 0) {
082c8cb4
DB		 1888 /* FIXME switch to an IDR based scheme, something like
1889 * I2C now uses, so we can't run out of "dynamic" IDs
1890 */
8ae12a0d 1891 master->bus_num = atomic_dec_return(&dyn_bus_id);
b885244e 1892 dynamic = 1;
8ae12a0d
DB		 1893 }
1894
5424d43e
MB		 1895 INIT_LIST_HEAD(&master->queue);
1896 spin_lock_init(&master->queue_lock);
cf32b71e
ES		 1897 spin_lock_init(&master->bus_lock_spinlock);
1898 mutex_init(&master->bus_lock_mutex);
ef4d96ec 1899 mutex_init(&master->io_mutex);
cf32b71e 1900 master->bus_lock_flag = 0;
b158935f 1901 init_completion(&master->xfer_completion);
6ad45a27
MB		 1902 if (!master->max_dma_len)
1903 master->max_dma_len = INT_MAX;
cf32b71e 1904
8ae12a0d
DB		 1905 /* register the device, then userspace will see it.
1906 * registration fails if the bus ID is in use.
1907 */
35f74fca 1908 dev_set_name(&master->dev, "spi%u", master->bus_num);
49dce689 1909 status = device_add(&master->dev);
b885244e 1910 if (status < 0)
8ae12a0d 1911 goto done;
35f74fca 1912 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
8ae12a0d
DB		 1913 dynamic ? " (dynamic)" : "");
1914
ffbbdd21
LW		 1915 /* If we're using a queued driver, start the queue */
1916 if (master->transfer)
1917 dev_info(dev, "master is unqueued, this is deprecated\n");
1918 else {
1919 status = spi_master_initialize_queue(master);
1920 if (status) {
e93b0724 1921 device_del(&master->dev);
ffbbdd21
LW		 1922 goto done;
1923 }
1924 }
eca2ebc7
MS		 1925 /* add statistics */
1926 spin_lock_init(&master->statistics.lock);
ffbbdd21 1927
2b9603a0
FT		 1928 mutex_lock(&board_lock);
1929 list_add_tail(&master->list, &spi_master_list);
1930 list_for_each_entry(bi, &board_list, list)
1931 spi_match_master_to_boardinfo(master, &bi->board_info);
1932 mutex_unlock(&board_lock);
1933
64bee4d2 1934 /* Register devices from the device tree and ACPI */
12b15e83 1935 of_register_spi_devices(master);
64bee4d2 1936 acpi_register_spi_devices(master);
8ae12a0d
DB		 1937done:
1938 return status;
1939}
1940EXPORT_SYMBOL_GPL(spi_register_master);
1941
666d5b4c
MB		 1942static void devm_spi_unregister(struct device *dev, void *res)
1943{
1944 spi_unregister_master(*(struct spi_master **)res);
1945}
1946
1947/**
1948 * dev_spi_register_master - register managed SPI master controller
1949 * @dev: device managing SPI master
1950 * @master: initialized master, originally from spi_alloc_master()
1951 * Context: can sleep
1952 *
1953 * Register a SPI device as with spi_register_master() which will
1954 * automatically be unregister
97d56dc6
JMC		 1955 *
1956 * Return: zero on success, else a negative error code.
666d5b4c
MB		 1957 */
1958int devm_spi_register_master(struct device *dev, struct spi_master *master)
1959{
1960 struct spi_master **ptr;
1961 int ret;
1962
1963 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1964 if (!ptr)
1965 return -ENOMEM;
1966
1967 ret = spi_register_master(master);
4b92894e 1968 if (!ret) {
666d5b4c
MB		 1969 *ptr = master;
1970 devres_add(dev, ptr);
1971 } else {
1972 devres_free(ptr);
1973 }
1974
1975 return ret;
1976}
1977EXPORT_SYMBOL_GPL(devm_spi_register_master);
1978
34860089 1979static int __unregister(struct device *dev, void *null)
8ae12a0d 1980{
34860089 1981 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 1982 return 0;
1983}
1984
1985/**
1986 * spi_unregister_master - unregister SPI master controller
1987 * @master: the master being unregistered
33e34dc6 1988 * Context: can sleep
8ae12a0d
DB		 1989 *
1990 * This call is used only by SPI master controller drivers, which are the
1991 * only ones directly touching chip registers.
1992 *
1993 * This must be called from context that can sleep.
1994 */
1995void spi_unregister_master(struct spi_master *master)
1996{
89fc9a1a
JG		 1997 int dummy;
1998
ffbbdd21
LW		 1999 if (master->queued) {
2000 if (spi_destroy_queue(master))
2001 dev_err(&master->dev, "queue remove failed\n");
2002 }
2003
2b9603a0
FT		 2004 mutex_lock(&board_lock);
2005 list_del(&master->list);
2006 mutex_unlock(&board_lock);
2007
97dbf37d 2008 dummy = device_for_each_child(&master->dev, NULL, __unregister);
49dce689 2009 device_unregister(&master->dev);
8ae12a0d
DB		 2010}
2011EXPORT_SYMBOL_GPL(spi_unregister_master);
2012
ffbbdd21
LW		 2013int spi_master_suspend(struct spi_master *master)
2014{
2015 int ret;
2016
2017 /* Basically no-ops for non-queued masters */
2018 if (!master->queued)
2019 return 0;
2020
2021 ret = spi_stop_queue(master);
2022 if (ret)
2023 dev_err(&master->dev, "queue stop failed\n");
2024
2025 return ret;
2026}
2027EXPORT_SYMBOL_GPL(spi_master_suspend);
2028
2029int spi_master_resume(struct spi_master *master)
2030{
2031 int ret;
2032
2033 if (!master->queued)
2034 return 0;
2035
2036 ret = spi_start_queue(master);
2037 if (ret)
2038 dev_err(&master->dev, "queue restart failed\n");
2039
2040 return ret;
2041}
2042EXPORT_SYMBOL_GPL(spi_master_resume);
2043
9f3b795a 2044static int __spi_master_match(struct device *dev, const void *data)
5ed2c832
DY		 2045{
2046 struct spi_master *m;
9f3b795a 2047 const u16 *bus_num = data;
5ed2c832
DY		 2048
2049 m = container_of(dev, struct spi_master, dev);
2050 return m->bus_num == *bus_num;
2051}
2052
8ae12a0d
DB		 2053/**
2054 * spi_busnum_to_master - look up master associated with bus_num
2055 * @bus_num: the master's bus number
33e34dc6 2056 * Context: can sleep
8ae12a0d
DB		 2057 *
2058 * This call may be used with devices that are registered after
2059 * arch init time. It returns a refcounted pointer to the relevant
2060 * spi_master (which the caller must release), or NULL if there is
2061 * no such master registered.
97d56dc6
JMC		 2062 *
2063 * Return: the SPI master structure on success, else NULL.
8ae12a0d
DB		 2064 */
2065struct spi_master *spi_busnum_to_master(u16 bus_num)
2066{
49dce689 2067 struct device *dev;
1e9a51dc 2068 struct spi_master *master = NULL;
5ed2c832 2069
695794ae 2070 dev = class_find_device(&spi_master_class, NULL, &bus_num,
5ed2c832
DY		 2071 __spi_master_match);
2072 if (dev)
2073 master = container_of(dev, struct spi_master, dev);
2074 /* reference got in class_find_device */
1e9a51dc 2075 return master;
8ae12a0d
DB		 2076}
2077EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2078
d780c371
MS		 2079/*-------------------------------------------------------------------------*/
2080
2081/* Core methods for SPI resource management */
2082
2083/**
2084 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2085 * during the processing of a spi_message while using
2086 * spi_transfer_one
2087 * @spi: the spi device for which we allocate memory
2088 * @release: the release code to execute for this resource
2089 * @size: size to alloc and return
2090 * @gfp: GFP allocation flags
2091 *
2092 * Return: the pointer to the allocated data
2093 *
2094 * This may get enhanced in the future to allocate from a memory pool
2095 * of the @spi_device or @spi_master to avoid repeated allocations.
2096 */
2097void *spi_res_alloc(struct spi_device *spi,
2098 spi_res_release_t release,
2099 size_t size, gfp_t gfp)
2100{
2101 struct spi_res *sres;
2102
2103 sres = kzalloc(sizeof(*sres) + size, gfp);
2104 if (!sres)
2105 return NULL;
2106
2107 INIT_LIST_HEAD(&sres->entry);
2108 sres->release = release;
2109
2110 return sres->data;
2111}
2112EXPORT_SYMBOL_GPL(spi_res_alloc);
2113
2114/**
2115 * spi_res_free - free an spi resource
2116 * @res: pointer to the custom data of a resource
2117 *
2118 */
2119void spi_res_free(void *res)
2120{
2121 struct spi_res *sres = container_of(res, struct spi_res, data);
2122
2123 if (!res)
2124 return;
2125
2126 WARN_ON(!list_empty(&sres->entry));
2127 kfree(sres);
2128}
2129EXPORT_SYMBOL_GPL(spi_res_free);
2130
2131/**
2132 * spi_res_add - add a spi_res to the spi_message
2133 * @message: the spi message
2134 * @res: the spi_resource
2135 */
2136void spi_res_add(struct spi_message *message, void *res)
2137{
2138 struct spi_res *sres = container_of(res, struct spi_res, data);
2139
2140 WARN_ON(!list_empty(&sres->entry));
2141 list_add_tail(&sres->entry, &message->resources);
2142}
2143EXPORT_SYMBOL_GPL(spi_res_add);
2144
2145/**
2146 * spi_res_release - release all spi resources for this message
2147 * @master: the @spi_master
2148 * @message: the @spi_message
2149 */
2150void spi_res_release(struct spi_master *master,
2151 struct spi_message *message)
2152{
2153 struct spi_res *res;
2154
2155 while (!list_empty(&message->resources)) {
2156 res = list_last_entry(&message->resources,
2157 struct spi_res, entry);
2158
2159 if (res->release)
2160 res->release(master, message, res->data);
2161
2162 list_del(&res->entry);
2163
2164 kfree(res);
2165 }
2166}
2167EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2168
2169/*-------------------------------------------------------------------------*/
2170
523baf5a
MS		 2171/* Core methods for spi_message alterations */
2172
2173static void __spi_replace_transfers_release(struct spi_master *master,
2174 struct spi_message *msg,
2175 void *res)
2176{
2177 struct spi_replaced_transfers *rxfer = res;
2178 size_t i;
2179
2180 /* call extra callback if requested */
2181 if (rxfer->release)
2182 rxfer->release(master, msg, res);
2183
2184 /* insert replaced transfers back into the message */
2185 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2186
2187 /* remove the formerly inserted entries */
2188 for (i = 0; i < rxfer->inserted; i++)
2189 list_del(&rxfer->inserted_transfers[i].transfer_list);
2190}
2191
2192/**
2193 * spi_replace_transfers - replace transfers with several transfers
2194 * and register change with spi_message.resources
2195 * @msg: the spi_message we work upon
2196 * @xfer_first: the first spi_transfer we want to replace
2197 * @remove: number of transfers to remove
2198 * @insert: the number of transfers we want to insert instead
2199 * @release: extra release code necessary in some circumstances
2200 * @extradatasize: extra data to allocate (with alignment guarantees
2201 * of struct @spi_transfer)
05885397 2202 * @gfp: gfp flags
523baf5a
MS		 2203 *
2204 * Returns: pointer to @spi_replaced_transfers,
2205 * PTR_ERR(...) in case of errors.
2206 */
2207struct spi_replaced_transfers *spi_replace_transfers(
2208 struct spi_message *msg,
2209 struct spi_transfer *xfer_first,
2210 size_t remove,
2211 size_t insert,
2212 spi_replaced_release_t release,
2213 size_t extradatasize,
2214 gfp_t gfp)
2215{
2216 struct spi_replaced_transfers *rxfer;
2217 struct spi_transfer *xfer;
2218 size_t i;
2219
2220 /* allocate the structure using spi_res */
2221 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2222 insert * sizeof(struct spi_transfer)
2223 + sizeof(struct spi_replaced_transfers)
2224 + extradatasize,
2225 gfp);
2226 if (!rxfer)
2227 return ERR_PTR(-ENOMEM);
2228
2229 /* the release code to invoke before running the generic release */
2230 rxfer->release = release;
2231
2232 /* assign extradata */
2233 if (extradatasize)
2234 rxfer->extradata =
2235 &rxfer->inserted_transfers[insert];
2236
2237 /* init the replaced_transfers list */
2238 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2239
2240 /* assign the list_entry after which we should reinsert
2241 * the @replaced_transfers - it may be spi_message.messages!
2242 */
2243 rxfer->replaced_after = xfer_first->transfer_list.prev;
2244
2245 /* remove the requested number of transfers */
2246 for (i = 0; i < remove; i++) {
2247 /* if the entry after replaced_after it is msg->transfers
2248 * then we have been requested to remove more transfers
2249 * than are in the list
2250 */
2251 if (rxfer->replaced_after->next == &msg->transfers) {
2252 dev_err(&msg->spi->dev,
2253 "requested to remove more spi_transfers than are available\n");
2254 /* insert replaced transfers back into the message */
2255 list_splice(&rxfer->replaced_transfers,
2256 rxfer->replaced_after);
2257
2258 /* free the spi_replace_transfer structure */
2259 spi_res_free(rxfer);
2260
2261 /* and return with an error */
2262 return ERR_PTR(-EINVAL);
2263 }
2264
2265 /* remove the entry after replaced_after from list of
2266 * transfers and add it to list of replaced_transfers
2267 */
2268 list_move_tail(rxfer->replaced_after->next,
2269 &rxfer->replaced_transfers);
2270 }
2271
2272 /* create copy of the given xfer with identical settings
2273 * based on the first transfer to get removed
2274 */
2275 for (i = 0; i < insert; i++) {
2276 /* we need to run in reverse order */
2277 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2278
2279 /* copy all spi_transfer data */
2280 memcpy(xfer, xfer_first, sizeof(*xfer));
2281
2282 /* add to list */
2283 list_add(&xfer->transfer_list, rxfer->replaced_after);
2284
2285 /* clear cs_change and delay_usecs for all but the last */
2286 if (i) {
2287 xfer->cs_change = false;
2288 xfer->delay_usecs = 0;
2289 }
2290 }
2291
2292 /* set up inserted */
2293 rxfer->inserted = insert;
2294
2295 /* and register it with spi_res/spi_message */
2296 spi_res_add(msg, rxfer);
2297
2298 return rxfer;
2299}
2300EXPORT_SYMBOL_GPL(spi_replace_transfers);
2301
08933418
FE		 2302static int __spi_split_transfer_maxsize(struct spi_master *master,
2303 struct spi_message *msg,
2304 struct spi_transfer **xferp,
2305 size_t maxsize,
2306 gfp_t gfp)
d9f12122
MS		 2307{
2308 struct spi_transfer *xfer = *xferp, *xfers;
2309 struct spi_replaced_transfers *srt;
2310 size_t offset;
2311 size_t count, i;
2312
2313 /* warn once about this fact that we are splitting a transfer */
2314 dev_warn_once(&msg->spi->dev,
7d62f51e 2315 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
d9f12122
MS		 2316 xfer->len, maxsize);
2317
2318 /* calculate how many we have to replace */
2319 count = DIV_ROUND_UP(xfer->len, maxsize);
2320
2321 /* create replacement */
2322 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2323 if (IS_ERR(srt))
2324 return PTR_ERR(srt);
d9f12122
MS		 2325 xfers = srt->inserted_transfers;
2326
2327 /* now handle each of those newly inserted spi_transfers
2328 * note that the replacements spi_transfers all are preset
2329 * to the same values as *xferp, so tx_buf, rx_buf and len
2330 * are all identical (as well as most others)
2331 * so we just have to fix up len and the pointers.
2332 *
2333 * this also includes support for the depreciated
2334 * spi_message.is_dma_mapped interface
2335 */
2336
2337 /* the first transfer just needs the length modified, so we
2338 * run it outside the loop
2339 */
c8dab77a 2340 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
d9f12122
MS		 2341
2342 /* all the others need rx_buf/tx_buf also set */
2343 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2344 /* update rx_buf, tx_buf and dma */
2345 if (xfers[i].rx_buf)
2346 xfers[i].rx_buf += offset;
2347 if (xfers[i].rx_dma)
2348 xfers[i].rx_dma += offset;
2349 if (xfers[i].tx_buf)
2350 xfers[i].tx_buf += offset;
2351 if (xfers[i].tx_dma)
2352 xfers[i].tx_dma += offset;
2353
2354 /* update length */
2355 xfers[i].len = min(maxsize, xfers[i].len - offset);
2356 }
2357
2358 /* we set up xferp to the last entry we have inserted,
2359 * so that we skip those already split transfers
2360 */
2361 *xferp = &xfers[count - 1];
2362
2363 /* increment statistics counters */
2364 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2365 transfers_split_maxsize);
2366 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2367 transfers_split_maxsize);
2368
2369 return 0;
2370}
2371
2372/**
2373 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2374 * when an individual transfer exceeds a
2375 * certain size
2376 * @master: the @spi_master for this transfer
3700ce95
MI		 2377 * @msg: the @spi_message to transform
2378 * @maxsize: the maximum when to apply this
10f11a22 2379 * @gfp: GFP allocation flags
d9f12122
MS		 2380 *
2381 * Return: status of transformation
2382 */
2383int spi_split_transfers_maxsize(struct spi_master *master,
2384 struct spi_message *msg,
2385 size_t maxsize,
2386 gfp_t gfp)
2387{
2388 struct spi_transfer *xfer;
2389 int ret;
2390
2391 /* iterate over the transfer_list,
2392 * but note that xfer is advanced to the last transfer inserted
2393 * to avoid checking sizes again unnecessarily (also xfer does
2394 * potentiall belong to a different list by the time the
2395 * replacement has happened
2396 */
2397 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2398 if (xfer->len > maxsize) {
2399 ret = __spi_split_transfer_maxsize(
2400 master, msg, &xfer, maxsize, gfp);
2401 if (ret)
2402 return ret;
2403 }
2404 }
2405
2406 return 0;
2407}
2408EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
8ae12a0d
DB		 2409
2410/*-------------------------------------------------------------------------*/
2411
7d077197
DB		 2412/* Core methods for SPI master protocol drivers. Some of the
2413 * other core methods are currently defined as inline functions.
2414 */
2415
63ab645f
SB		 2416static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2417{
2418 if (master->bits_per_word_mask) {
2419 /* Only 32 bits fit in the mask */
2420 if (bits_per_word > 32)
2421 return -EINVAL;
2422 if (!(master->bits_per_word_mask &
2423 SPI_BPW_MASK(bits_per_word)))
2424 return -EINVAL;
2425 }
2426
2427 return 0;
2428}
2429
7d077197
DB		 2430/**
2431 * spi_setup - setup SPI mode and clock rate
2432 * @spi: the device whose settings are being modified
2433 * Context: can sleep, and no requests are queued to the device
2434 *
2435 * SPI protocol drivers may need to update the transfer mode if the
2436 * device doesn't work with its default. They may likewise need
2437 * to update clock rates or word sizes from initial values. This function
2438 * changes those settings, and must be called from a context that can sleep.
2439 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2440 * effect the next time the device is selected and data is transferred to
2441 * or from it. When this function returns, the spi device is deselected.
2442 *
2443 * Note that this call will fail if the protocol driver specifies an option
2444 * that the underlying controller or its driver does not support. For
2445 * example, not all hardware supports wire transfers using nine bit words,
2446 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2447 *
2448 * Return: zero on success, else a negative error code.
7d077197
DB		 2449 */
2450int spi_setup(struct spi_device *spi)
2451{
83596fbe 2452 unsigned bad_bits, ugly_bits;
5ab8d262 2453 int status;
7d077197 2454
f477b7fb 2455 /* check mode to prevent that DUAL and QUAD set at the same time
2456 */
2457 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2458 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2459 dev_err(&spi->dev,
2460 "setup: can not select dual and quad at the same time\n");
2461 return -EINVAL;
2462 }
2463 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2464 */
2465 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2466 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2467 return -EINVAL;
e7db06b5
DB		 2468 /* help drivers fail *cleanly* when they need options
2469 * that aren't supported with their current master
2470 */
2471 bad_bits = spi->mode & ~spi->master->mode_bits;
83596fbe
GU		 2472 ugly_bits = bad_bits &
2473 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2474 if (ugly_bits) {
2475 dev_warn(&spi->dev,
2476 "setup: ignoring unsupported mode bits %x\n",
2477 ugly_bits);
2478 spi->mode &= ~ugly_bits;
2479 bad_bits &= ~ugly_bits;
2480 }
e7db06b5 2481 if (bad_bits) {
eb288a1f 2482 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2483 bad_bits);
2484 return -EINVAL;
2485 }
2486
7d077197
DB		 2487 if (!spi->bits_per_word)
2488 spi->bits_per_word = 8;
2489
5ab8d262
AS		 2490 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2491 if (status)
2492 return status;
63ab645f 2493
052eb2d4
AL		 2494 if (!spi->max_speed_hz)
2495 spi->max_speed_hz = spi->master->max_speed_hz;
2496
caae070c
LD		 2497 if (spi->master->setup)
2498 status = spi->master->setup(spi);
7d077197 2499
abeedb01
FCJ		 2500 spi_set_cs(spi, false);
2501
5fe5f05e 2502 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2503 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2504 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2505 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2506 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2507 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2508 spi->bits_per_word, spi->max_speed_hz,
2509 status);
2510
2511 return status;
2512}
2513EXPORT_SYMBOL_GPL(spi_setup);
2514
90808738 2515static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2516{
2517 struct spi_master *master = spi->master;
e6811d1d 2518 struct spi_transfer *xfer;
6ea31293 2519 int w_size;
cf32b71e 2520
24a0013a
MB		 2521 if (list_empty(&message->transfers))
2522 return -EINVAL;
24a0013a 2523
cf32b71e
ES		 2524 /* Half-duplex links include original MicroWire, and ones with
2525 * only one data pin like SPI_3WIRE (switches direction) or where
2526 * either MOSI or MISO is missing. They can also be caused by
2527 * software limitations.
2528 */
2529 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2530 || (spi->mode & SPI_3WIRE)) {
cf32b71e
ES		 2531 unsigned flags = master->flags;
2532
2533 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2534 if (xfer->rx_buf && xfer->tx_buf)
2535 return -EINVAL;
2536 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2537 return -EINVAL;
2538 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2539 return -EINVAL;
2540 }
2541 }
2542
e6811d1d 2543 /**
059b8ffe
LD		 2544 * Set transfer bits_per_word and max speed as spi device default if
2545 * it is not set for this transfer.
f477b7fb 2546 * Set transfer tx_nbits and rx_nbits as single transfer default
2547 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2548 */
77e80588 2549 message->frame_length = 0;
e6811d1d 2550 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2551 message->frame_length += xfer->len;
e6811d1d
LD		 2552 if (!xfer->bits_per_word)
2553 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2554
2555 if (!xfer->speed_hz)
059b8ffe 2556 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3
MB		 2557 if (!xfer->speed_hz)
2558 xfer->speed_hz = master->max_speed_hz;
a6f87fad
AL		 2559
2560 if (master->max_speed_hz &&
2561 xfer->speed_hz > master->max_speed_hz)
2562 xfer->speed_hz = master->max_speed_hz;
56ede94a 2563
63ab645f
SB		 2564 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2565 return -EINVAL;
a2fd4f9f 2566
4d94bd21
II		 2567 /*
2568 * SPI transfer length should be multiple of SPI word size
2569 * where SPI word size should be power-of-two multiple
2570 */
2571 if (xfer->bits_per_word <= 8)
2572 w_size = 1;
2573 else if (xfer->bits_per_word <= 16)
2574 w_size = 2;
2575 else
2576 w_size = 4;
2577
4d94bd21 2578 /* No partial transfers accepted */
6ea31293 2579 if (xfer->len % w_size)
4d94bd21
II		 2580 return -EINVAL;
2581
a2fd4f9f
MB		 2582 if (xfer->speed_hz && master->min_speed_hz &&
2583 xfer->speed_hz < master->min_speed_hz)
2584 return -EINVAL;
f477b7fb 2585
2586 if (xfer->tx_buf && !xfer->tx_nbits)
2587 xfer->tx_nbits = SPI_NBITS_SINGLE;
2588 if (xfer->rx_buf && !xfer->rx_nbits)
2589 xfer->rx_nbits = SPI_NBITS_SINGLE;
2590 /* check transfer tx/rx_nbits:
1afd9989
GU		 2591 * 1. check the value matches one of single, dual and quad
2592 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 2593 */
db90a441
SP		 2594 if (xfer->tx_buf) {
2595 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2596 xfer->tx_nbits != SPI_NBITS_DUAL &&
2597 xfer->tx_nbits != SPI_NBITS_QUAD)
2598 return -EINVAL;
2599 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2600 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2601 return -EINVAL;
2602 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2603 !(spi->mode & SPI_TX_QUAD))
2604 return -EINVAL;
db90a441 2605 }
f477b7fb 2606 /* check transfer rx_nbits */
db90a441
SP		 2607 if (xfer->rx_buf) {
2608 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2609 xfer->rx_nbits != SPI_NBITS_DUAL &&
2610 xfer->rx_nbits != SPI_NBITS_QUAD)
2611 return -EINVAL;
2612 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2613 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2614 return -EINVAL;
2615 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2616 !(spi->mode & SPI_RX_QUAD))
2617 return -EINVAL;
db90a441 2618 }
e6811d1d
LD		 2619 }
2620
cf32b71e 2621 message->status = -EINPROGRESS;
90808738
MB		 2622
2623 return 0;
2624}
2625
2626static int __spi_async(struct spi_device *spi, struct spi_message *message)
2627{
2628 struct spi_master *master = spi->master;
2629
2630 message->spi = spi;
2631
eca2ebc7
MS		 2632 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2633 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2634
90808738
MB		 2635 trace_spi_message_submit(message);
2636
cf32b71e
ES		 2637 return master->transfer(spi, message);
2638}
2639
568d0697
DB		 2640/**
2641 * spi_async - asynchronous SPI transfer
2642 * @spi: device with which data will be exchanged
2643 * @message: describes the data transfers, including completion callback
2644 * Context: any (irqs may be blocked, etc)
2645 *
2646 * This call may be used in_irq and other contexts which can't sleep,
2647 * as well as from task contexts which can sleep.
2648 *
2649 * The completion callback is invoked in a context which can't sleep.
2650 * Before that invocation, the value of message->status is undefined.
2651 * When the callback is issued, message->status holds either zero (to
2652 * indicate complete success) or a negative error code. After that
2653 * callback returns, the driver which issued the transfer request may
2654 * deallocate the associated memory; it's no longer in use by any SPI
2655 * core or controller driver code.
2656 *
2657 * Note that although all messages to a spi_device are handled in
2658 * FIFO order, messages may go to different devices in other orders.
2659 * Some device might be higher priority, or have various "hard" access
2660 * time requirements, for example.
2661 *
2662 * On detection of any fault during the transfer, processing of
2663 * the entire message is aborted, and the device is deselected.
2664 * Until returning from the associated message completion callback,
2665 * no other spi_message queued to that device will be processed.
2666 * (This rule applies equally to all the synchronous transfer calls,
2667 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2668 *
2669 * Return: zero on success, else a negative error code.
568d0697
DB		 2670 */
2671int spi_async(struct spi_device *spi, struct spi_message *message)
2672{
2673 struct spi_master *master = spi->master;
cf32b71e
ES		 2674 int ret;
2675 unsigned long flags;
568d0697 2676
90808738
MB		 2677 ret = __spi_validate(spi, message);
2678 if (ret != 0)
2679 return ret;
2680
cf32b71e 2681 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
568d0697 2682
cf32b71e
ES		 2683 if (master->bus_lock_flag)
2684 ret = -EBUSY;
2685 else
2686 ret = __spi_async(spi, message);
568d0697 2687
cf32b71e
ES		 2688 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2689
2690 return ret;
568d0697
DB		 2691}
2692EXPORT_SYMBOL_GPL(spi_async);
2693
cf32b71e
ES		 2694/**
2695 * spi_async_locked - version of spi_async with exclusive bus usage
2696 * @spi: device with which data will be exchanged
2697 * @message: describes the data transfers, including completion callback
2698 * Context: any (irqs may be blocked, etc)
2699 *
2700 * This call may be used in_irq and other contexts which can't sleep,
2701 * as well as from task contexts which can sleep.
2702 *
2703 * The completion callback is invoked in a context which can't sleep.
2704 * Before that invocation, the value of message->status is undefined.
2705 * When the callback is issued, message->status holds either zero (to
2706 * indicate complete success) or a negative error code. After that
2707 * callback returns, the driver which issued the transfer request may
2708 * deallocate the associated memory; it's no longer in use by any SPI
2709 * core or controller driver code.
2710 *
2711 * Note that although all messages to a spi_device are handled in
2712 * FIFO order, messages may go to different devices in other orders.
2713 * Some device might be higher priority, or have various "hard" access
2714 * time requirements, for example.
2715 *
2716 * On detection of any fault during the transfer, processing of
2717 * the entire message is aborted, and the device is deselected.
2718 * Until returning from the associated message completion callback,
2719 * no other spi_message queued to that device will be processed.
2720 * (This rule applies equally to all the synchronous transfer calls,
2721 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2722 *
2723 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2724 */
2725int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2726{
2727 struct spi_master *master = spi->master;
2728 int ret;
2729 unsigned long flags;
2730
90808738
MB		 2731 ret = __spi_validate(spi, message);
2732 if (ret != 0)
2733 return ret;
2734
cf32b71e
ES		 2735 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2736
2737 ret = __spi_async(spi, message);
2738
2739 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2740
2741 return ret;
2742
2743}
2744EXPORT_SYMBOL_GPL(spi_async_locked);
2745
7d077197 2746
556351f1
V		 2747int spi_flash_read(struct spi_device *spi,
2748 struct spi_flash_read_message *msg)
2749
2750{
2751 struct spi_master *master = spi->master;
f4502dd1 2752 struct device *rx_dev = NULL;
556351f1
V		 2753 int ret;
2754
2755 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2756 msg->addr_nbits == SPI_NBITS_DUAL) &&
2757 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2758 return -EINVAL;
2759 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2760 msg->addr_nbits == SPI_NBITS_QUAD) &&
2761 !(spi->mode & SPI_TX_QUAD))
2762 return -EINVAL;
2763 if (msg->data_nbits == SPI_NBITS_DUAL &&
2764 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2765 return -EINVAL;
2766 if (msg->data_nbits == SPI_NBITS_QUAD &&
2767 !(spi->mode & SPI_RX_QUAD))
2768 return -EINVAL;
2769
2770 if (master->auto_runtime_pm) {
2771 ret = pm_runtime_get_sync(master->dev.parent);
2772 if (ret < 0) {
2773 dev_err(&master->dev, "Failed to power device: %d\n",
2774 ret);
2775 return ret;
2776 }
2777 }
f4502dd1 2778
556351f1 2779 mutex_lock(&master->bus_lock_mutex);
ef4d96ec 2780 mutex_lock(&master->io_mutex);
f4502dd1
V		 2781 if (master->dma_rx) {
2782 rx_dev = master->dma_rx->device->dev;
2783 ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
2784 msg->buf, msg->len,
2785 DMA_FROM_DEVICE);
2786 if (!ret)
2787 msg->cur_msg_mapped = true;
2788 }
556351f1 2789 ret = master->spi_flash_read(spi, msg);
f4502dd1
V		 2790 if (msg->cur_msg_mapped)
2791 spi_unmap_buf(master, rx_dev, &msg->rx_sg,
2792 DMA_FROM_DEVICE);
ef4d96ec 2793 mutex_unlock(&master->io_mutex);
556351f1 2794 mutex_unlock(&master->bus_lock_mutex);
f4502dd1 2795
556351f1
V		 2796 if (master->auto_runtime_pm)
2797 pm_runtime_put(master->dev.parent);
2798
2799 return ret;
2800}
2801EXPORT_SYMBOL_GPL(spi_flash_read);
2802
7d077197
DB		 2803/*-------------------------------------------------------------------------*/
2804
2805/* Utility methods for SPI master protocol drivers, layered on
2806 * top of the core. Some other utility methods are defined as
2807 * inline functions.
2808 */
2809
5d870c8e
AM		 2810static void spi_complete(void *arg)
2811{
2812 complete(arg);
2813}
2814
ef4d96ec 2815static int __spi_sync(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2816{
2817 DECLARE_COMPLETION_ONSTACK(done);
2818 int status;
2819 struct spi_master *master = spi->master;
0461a414
MB		 2820 unsigned long flags;
2821
2822 status = __spi_validate(spi, message);
2823 if (status != 0)
2824 return status;
cf32b71e
ES		 2825
2826 message->complete = spi_complete;
2827 message->context = &done;
0461a414 2828 message->spi = spi;
cf32b71e 2829
eca2ebc7
MS		 2830 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2831 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2832
0461a414
MB		 2833 /* If we're not using the legacy transfer method then we will
2834 * try to transfer in the calling context so special case.
2835 * This code would be less tricky if we could remove the
2836 * support for driver implemented message queues.
2837 */
2838 if (master->transfer == spi_queued_transfer) {
2839 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2840
2841 trace_spi_message_submit(message);
2842
2843 status = __spi_queued_transfer(spi, message, false);
2844
2845 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2846 } else {
2847 status = spi_async_locked(spi, message);
2848 }
cf32b71e 2849
cf32b71e 2850 if (status == 0) {
0461a414
MB		 2851 /* Push out the messages in the calling context if we
2852 * can.
2853 */
eca2ebc7
MS		 2854 if (master->transfer == spi_queued_transfer) {
2855 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2856 spi_sync_immediate);
2857 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2858 spi_sync_immediate);
ef4d96ec 2859 __spi_pump_messages(master, false);
eca2ebc7 2860 }
0461a414 2861
cf32b71e
ES		 2862 wait_for_completion(&done);
2863 status = message->status;
2864 }
2865 message->context = NULL;
2866 return status;
2867}
2868
8ae12a0d
DB		 2869/**
2870 * spi_sync - blocking/synchronous SPI data transfers
2871 * @spi: device with which data will be exchanged
2872 * @message: describes the data transfers
33e34dc6 2873 * Context: can sleep
8ae12a0d
DB		 2874 *
2875 * This call may only be used from a context that may sleep. The sleep
2876 * is non-interruptible, and has no timeout. Low-overhead controller
2877 * drivers may DMA directly into and out of the message buffers.
2878 *
2879 * Note that the SPI device's chip select is active during the message,
2880 * and then is normally disabled between messages. Drivers for some
2881 * frequently-used devices may want to minimize costs of selecting a chip,
2882 * by leaving it selected in anticipation that the next message will go
2883 * to the same chip. (That may increase power usage.)
2884 *
0c868461
DB		 2885 * Also, the caller is guaranteeing that the memory associated with the
2886 * message will not be freed before this call returns.
2887 *
97d56dc6 2888 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2889 */
2890int spi_sync(struct spi_device *spi, struct spi_message *message)
2891{
ef4d96ec
MB		 2892 int ret;
2893
2894 mutex_lock(&spi->master->bus_lock_mutex);
2895 ret = __spi_sync(spi, message);
2896 mutex_unlock(&spi->master->bus_lock_mutex);
2897
2898 return ret;
8ae12a0d
DB		 2899}
2900EXPORT_SYMBOL_GPL(spi_sync);
2901
cf32b71e
ES		 2902/**
2903 * spi_sync_locked - version of spi_sync with exclusive bus usage
2904 * @spi: device with which data will be exchanged
2905 * @message: describes the data transfers
2906 * Context: can sleep
2907 *
2908 * This call may only be used from a context that may sleep. The sleep
2909 * is non-interruptible, and has no timeout. Low-overhead controller
2910 * drivers may DMA directly into and out of the message buffers.
2911 *
2912 * This call should be used by drivers that require exclusive access to the
25985edc 2913 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 2914 * be released by a spi_bus_unlock call when the exclusive access is over.
2915 *
97d56dc6 2916 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2917 */
2918int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2919{
ef4d96ec 2920 return __spi_sync(spi, message);
cf32b71e
ES		 2921}
2922EXPORT_SYMBOL_GPL(spi_sync_locked);
2923
2924/**
2925 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2926 * @master: SPI bus master that should be locked for exclusive bus access
2927 * Context: can sleep
2928 *
2929 * This call may only be used from a context that may sleep. The sleep
2930 * is non-interruptible, and has no timeout.
2931 *
2932 * This call should be used by drivers that require exclusive access to the
2933 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2934 * exclusive access is over. Data transfer must be done by spi_sync_locked
2935 * and spi_async_locked calls when the SPI bus lock is held.
2936 *
97d56dc6 2937 * Return: always zero.
cf32b71e
ES		 2938 */
2939int spi_bus_lock(struct spi_master *master)
2940{
2941 unsigned long flags;
2942
2943 mutex_lock(&master->bus_lock_mutex);
2944
2945 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2946 master->bus_lock_flag = 1;
2947 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2948
2949 /* mutex remains locked until spi_bus_unlock is called */
2950
2951 return 0;
2952}
2953EXPORT_SYMBOL_GPL(spi_bus_lock);
2954
2955/**
2956 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2957 * @master: SPI bus master that was locked for exclusive bus access
2958 * Context: can sleep
2959 *
2960 * This call may only be used from a context that may sleep. The sleep
2961 * is non-interruptible, and has no timeout.
2962 *
2963 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2964 * call.
2965 *
97d56dc6 2966 * Return: always zero.
cf32b71e
ES		 2967 */
2968int spi_bus_unlock(struct spi_master *master)
2969{
2970 master->bus_lock_flag = 0;
2971
2972 mutex_unlock(&master->bus_lock_mutex);
2973
2974 return 0;
2975}
2976EXPORT_SYMBOL_GPL(spi_bus_unlock);
2977
a9948b61 2978/* portable code must never pass more than 32 bytes */
5fe5f05e 2979#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 2980
2981static u8 *buf;
2982
2983/**
2984 * spi_write_then_read - SPI synchronous write followed by read
2985 * @spi: device with which data will be exchanged
2986 * @txbuf: data to be written (need not be dma-safe)
2987 * @n_tx: size of txbuf, in bytes
27570497
JP		 2988 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2989 * @n_rx: size of rxbuf, in bytes
33e34dc6 2990 * Context: can sleep
8ae12a0d
DB		 2991 *
2992 * This performs a half duplex MicroWire style transaction with the
2993 * device, sending txbuf and then reading rxbuf. The return value
2994 * is zero for success, else a negative errno status code.
b885244e 2995 * This call may only be used from a context that may sleep.
8ae12a0d 2996 *
0c868461 2997 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 2998 * portable code should never use this for more than 32 bytes.
2999 * Performance-sensitive or bulk transfer code should instead use
0c868461 3000 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 3001 *
3002 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 3003 */
3004int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 3005 const void *txbuf, unsigned n_tx,
3006 void *rxbuf, unsigned n_rx)
8ae12a0d 3007{
068f4070 3008 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 3009
3010 int status;
3011 struct spi_message message;
bdff549e 3012 struct spi_transfer x[2];
8ae12a0d
DB		 3013 u8 *local_buf;
3014
b3a223ee
MB		 3015 /* Use preallocated DMA-safe buffer if we can. We can't avoid
3016 * copying here, (as a pure convenience thing), but we can
3017 * keep heap costs out of the hot path unless someone else is
3018 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 3019 */
b3a223ee 3020 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 3021 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
3022 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 3023 if (!local_buf)
3024 return -ENOMEM;
3025 } else {
3026 local_buf = buf;
3027 }
8ae12a0d 3028
8275c642 3029 spi_message_init(&message);
5fe5f05e 3030 memset(x, 0, sizeof(x));
bdff549e
DB		 3031 if (n_tx) {
3032 x[0].len = n_tx;
3033 spi_message_add_tail(&x[0], &message);
3034 }
3035 if (n_rx) {
3036 x[1].len = n_rx;
3037 spi_message_add_tail(&x[1], &message);
3038 }
8275c642 3039
8ae12a0d 3040 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 3041 x[0].tx_buf = local_buf;
3042 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 3043
3044 /* do the i/o */
8ae12a0d 3045 status = spi_sync(spi, &message);
9b938b74 3046 if (status == 0)
bdff549e 3047 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 3048
bdff549e 3049 if (x[0].tx_buf == buf)
068f4070 3050 mutex_unlock(&lock);
8ae12a0d
DB		 3051 else
3052 kfree(local_buf);
3053
3054 return status;
3055}
3056EXPORT_SYMBOL_GPL(spi_write_then_read);
3057
3058/*-------------------------------------------------------------------------*/
3059
ce79d54a
PA		 3060#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3061static int __spi_of_device_match(struct device *dev, void *data)
3062{
3063 return dev->of_node == data;
3064}
3065
3066/* must call put_device() when done with returned spi_device device */
3067static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3068{
3069 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3070 __spi_of_device_match);
3071 return dev ? to_spi_device(dev) : NULL;
3072}
3073
3074static int __spi_of_master_match(struct device *dev, const void *data)
3075{
3076 return dev->of_node == data;
3077}
3078
3079/* the spi masters are not using spi_bus, so we find it with another way */
3080static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3081{
3082 struct device *dev;
3083
3084 dev = class_find_device(&spi_master_class, NULL, node,
3085 __spi_of_master_match);
3086 if (!dev)
3087 return NULL;
3088
3089 /* reference got in class_find_device */
3090 return container_of(dev, struct spi_master, dev);
3091}
3092
3093static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3094 void *arg)
3095{
3096 struct of_reconfig_data *rd = arg;
3097 struct spi_master *master;
3098 struct spi_device *spi;
3099
3100 switch (of_reconfig_get_state_change(action, arg)) {
3101 case OF_RECONFIG_CHANGE_ADD:
3102 master = of_find_spi_master_by_node(rd->dn->parent);
3103 if (master == NULL)
3104 return NOTIFY_OK; /* not for us */
3105
bd6c1644
GU		 3106 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3107 put_device(&master->dev);
3108 return NOTIFY_OK;
3109 }
3110
ce79d54a
PA		 3111 spi = of_register_spi_device(master, rd->dn);
3112 put_device(&master->dev);
3113
3114 if (IS_ERR(spi)) {
3115 pr_err("%s: failed to create for '%s'\n",
3116 __func__, rd->dn->full_name);
3117 return notifier_from_errno(PTR_ERR(spi));
3118 }
3119 break;
3120
3121 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3122 /* already depopulated? */
3123 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3124 return NOTIFY_OK;
3125
ce79d54a
PA		 3126 /* find our device by node */
3127 spi = of_find_spi_device_by_node(rd->dn);
3128 if (spi == NULL)
3129 return NOTIFY_OK; /* no? not meant for us */
3130
3131 /* unregister takes one ref away */
3132 spi_unregister_device(spi);
3133
3134 /* and put the reference of the find */
3135 put_device(&spi->dev);
3136 break;
3137 }
3138
3139 return NOTIFY_OK;
3140}
3141
3142static struct notifier_block spi_of_notifier = {
3143 .notifier_call = of_spi_notify,
3144};
3145#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3146extern struct notifier_block spi_of_notifier;
3147#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3148
7f24467f
OP		 3149#if IS_ENABLED(CONFIG_ACPI)
3150static int spi_acpi_master_match(struct device *dev, const void *data)
3151{
3152 return ACPI_COMPANION(dev->parent) == data;
3153}
3154
3155static int spi_acpi_device_match(struct device *dev, void *data)
3156{
3157 return ACPI_COMPANION(dev) == data;
3158}
3159
3160static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev)
3161{
3162 struct device *dev;
3163
3164 dev = class_find_device(&spi_master_class, NULL, adev,
3165 spi_acpi_master_match);
3166 if (!dev)
3167 return NULL;
3168
3169 return container_of(dev, struct spi_master, dev);
3170}
3171
3172static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
3173{
3174 struct device *dev;
3175
3176 dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
3177
3178 return dev ? to_spi_device(dev) : NULL;
3179}
3180
3181static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
3182 void *arg)
3183{
3184 struct acpi_device *adev = arg;
3185 struct spi_master *master;
3186 struct spi_device *spi;
3187
3188 switch (value) {
3189 case ACPI_RECONFIG_DEVICE_ADD:
3190 master = acpi_spi_find_master_by_adev(adev->parent);
3191 if (!master)
3192 break;
3193
3194 acpi_register_spi_device(master, adev);
3195 put_device(&master->dev);
3196 break;
3197 case ACPI_RECONFIG_DEVICE_REMOVE:
3198 if (!acpi_device_enumerated(adev))
3199 break;
3200
3201 spi = acpi_spi_find_device_by_adev(adev);
3202 if (!spi)
3203 break;
3204
3205 spi_unregister_device(spi);
3206 put_device(&spi->dev);
3207 break;
3208 }
3209
3210 return NOTIFY_OK;
3211}
3212
3213static struct notifier_block spi_acpi_notifier = {
3214 .notifier_call = acpi_spi_notify,
3215};
3216#else
3217extern struct notifier_block spi_acpi_notifier;
3218#endif
3219
8ae12a0d
DB		 3220static int __init spi_init(void)
3221{
b885244e
DB		 3222 int status;
3223
e94b1766 3224 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3225 if (!buf) {
3226 status = -ENOMEM;
3227 goto err0;
3228 }
3229
3230 status = bus_register(&spi_bus_type);
3231 if (status < 0)
3232 goto err1;
8ae12a0d 3233
b885244e
DB		 3234 status = class_register(&spi_master_class);
3235 if (status < 0)
3236 goto err2;
ce79d54a 3237
5267720e 3238 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a 3239 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
7f24467f
OP		 3240 if (IS_ENABLED(CONFIG_ACPI))
3241 WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
ce79d54a 3242
8ae12a0d 3243 return 0;
b885244e
DB		 3244
3245err2:
3246 bus_unregister(&spi_bus_type);
3247err1:
3248 kfree(buf);
3249 buf = NULL;
3250err0:
3251 return status;
8ae12a0d 3252}
b885244e 3253
8ae12a0d
DB		 3254/* board_info is normally registered in arch_initcall(),
3255 * but even essential drivers wait till later
b885244e
DB		 3256 *
3257 * REVISIT only boardinfo really needs static linking. the rest (device and
3258 * driver registration) _could_ be dynamically linked (modular) ... costs
3259 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3260 */
673c0c00 3261postcore_initcall(spi_init);
8ae12a0d 3262
Linux 6.x block layer and io_uring tree(s)