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spi: core: Staticize __spi_split_transfer_maxsize()
[mirror_ubuntu-focal-kernel.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);
625 device_unregister(&spi->dev);
3b1884c2
GU		 626}
627EXPORT_SYMBOL_GPL(spi_unregister_device);
628
2b9603a0
FT		 629static void spi_match_master_to_boardinfo(struct spi_master *master,
630 struct spi_board_info *bi)
631{
632 struct spi_device *dev;
633
634 if (master->bus_num != bi->bus_num)
635 return;
636
637 dev = spi_new_device(master, bi);
638 if (!dev)
639 dev_err(master->dev.parent, "can't create new device for %s\n",
640 bi->modalias);
641}
642
33e34dc6
DB		 643/**
644 * spi_register_board_info - register SPI devices for a given board
645 * @info: array of chip descriptors
646 * @n: how many descriptors are provided
647 * Context: can sleep
648 *
8ae12a0d
DB		 649 * Board-specific early init code calls this (probably during arch_initcall)
650 * with segments of the SPI device table. Any device nodes are created later,
651 * after the relevant parent SPI controller (bus_num) is defined. We keep
652 * this table of devices forever, so that reloading a controller driver will
653 * not make Linux forget about these hard-wired devices.
654 *
655 * Other code can also call this, e.g. a particular add-on board might provide
656 * SPI devices through its expansion connector, so code initializing that board
657 * would naturally declare its SPI devices.
658 *
659 * The board info passed can safely be __initdata ... but be careful of
660 * any embedded pointers (platform_data, etc), they're copied as-is.
97d56dc6
JMC		 661 *
662 * Return: zero on success, else a negative error code.
8ae12a0d 663 */
fd4a319b 664int spi_register_board_info(struct spi_board_info const *info, unsigned n)
8ae12a0d 665{
2b9603a0
FT		 666 struct boardinfo *bi;
667 int i;
8ae12a0d 668
c7908a37
XL		 669 if (!n)
670 return -EINVAL;
671
2b9603a0 672 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
8ae12a0d
DB		 673 if (!bi)
674 return -ENOMEM;
8ae12a0d 675
2b9603a0
FT		 676 for (i = 0; i < n; i++, bi++, info++) {
677 struct spi_master *master;
8ae12a0d 678
2b9603a0
FT		 679 memcpy(&bi->board_info, info, sizeof(*info));
680 mutex_lock(&board_lock);
681 list_add_tail(&bi->list, &board_list);
682 list_for_each_entry(master, &spi_master_list, list)
683 spi_match_master_to_boardinfo(master, &bi->board_info);
684 mutex_unlock(&board_lock);
8ae12a0d 685 }
2b9603a0
FT		 686
687 return 0;
8ae12a0d
DB		 688}
689
690/*-------------------------------------------------------------------------*/
691
b158935f
MB		 692static void spi_set_cs(struct spi_device *spi, bool enable)
693{
694 if (spi->mode & SPI_CS_HIGH)
695 enable = !enable;
696
243f07be 697 if (gpio_is_valid(spi->cs_gpio))
b158935f
MB		 698 gpio_set_value(spi->cs_gpio, !enable);
699 else if (spi->master->set_cs)
700 spi->master->set_cs(spi, !enable);
701}
702
2de440f5 703#ifdef CONFIG_HAS_DMA
6ad45a27
MB		 704static int spi_map_buf(struct spi_master *master, struct device *dev,
705 struct sg_table *sgt, void *buf, size_t len,
706 enum dma_data_direction dir)
707{
708 const bool vmalloced_buf = is_vmalloc_addr(buf);
65598c13
AG		 709 int desc_len;
710 int sgs;
6ad45a27
MB		 711 struct page *vm_page;
712 void *sg_buf;
713 size_t min;
714 int i, ret;
715
65598c13
AG		 716 if (vmalloced_buf) {
717 desc_len = PAGE_SIZE;
718 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
719 } else {
720 desc_len = master->max_dma_len;
721 sgs = DIV_ROUND_UP(len, desc_len);
722 }
723
6ad45a27
MB		 724 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
725 if (ret != 0)
726 return ret;
727
728 for (i = 0; i < sgs; i++) {
6ad45a27
MB		 729
730 if (vmalloced_buf) {
65598c13
AG		 731 min = min_t(size_t,
732 len, desc_len - offset_in_page(buf));
6ad45a27
MB		 733 vm_page = vmalloc_to_page(buf);
734 if (!vm_page) {
735 sg_free_table(sgt);
736 return -ENOMEM;
737 }
c1aefbdd
CK		 738 sg_set_page(&sgt->sgl[i], vm_page,
739 min, offset_in_page(buf));
6ad45a27 740 } else {
65598c13 741 min = min_t(size_t, len, desc_len);
6ad45a27 742 sg_buf = buf;
c1aefbdd 743 sg_set_buf(&sgt->sgl[i], sg_buf, min);
6ad45a27
MB		 744 }
745
6ad45a27
MB		 746
747 buf += min;
748 len -= min;
749 }
750
751 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
89e4b66a
GU		 752 if (!ret)
753 ret = -ENOMEM;
6ad45a27
MB		 754 if (ret < 0) {
755 sg_free_table(sgt);
756 return ret;
757 }
758
759 sgt->nents = ret;
760
761 return 0;
762}
763
764static void spi_unmap_buf(struct spi_master *master, struct device *dev,
765 struct sg_table *sgt, enum dma_data_direction dir)
766{
767 if (sgt->orig_nents) {
768 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
769 sg_free_table(sgt);
770 }
771}
772
2de440f5 773static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
99adef31 774{
99adef31
MB		 775 struct device *tx_dev, *rx_dev;
776 struct spi_transfer *xfer;
6ad45a27 777 int ret;
3a2eba9b 778
6ad45a27 779 if (!master->can_dma)
99adef31
MB		 780 return 0;
781
c37f45b5
LL		 782 if (master->dma_tx)
783 tx_dev = master->dma_tx->device->dev;
784 else
785 tx_dev = &master->dev;
786
787 if (master->dma_rx)
788 rx_dev = master->dma_rx->device->dev;
789 else
790 rx_dev = &master->dev;
99adef31
MB		 791
792 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
793 if (!master->can_dma(master, msg->spi, xfer))
794 continue;
795
796 if (xfer->tx_buf != NULL) {
6ad45a27
MB		 797 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
798 (void *)xfer->tx_buf, xfer->len,
799 DMA_TO_DEVICE);
800 if (ret != 0)
801 return ret;
99adef31
MB		 802 }
803
804 if (xfer->rx_buf != NULL) {
6ad45a27
MB		 805 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
806 xfer->rx_buf, xfer->len,
807 DMA_FROM_DEVICE);
808 if (ret != 0) {
809 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
810 DMA_TO_DEVICE);
811 return ret;
99adef31
MB		 812 }
813 }
814 }
815
816 master->cur_msg_mapped = true;
817
818 return 0;
819}
820
4b786458 821static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
99adef31
MB		 822{
823 struct spi_transfer *xfer;
824 struct device *tx_dev, *rx_dev;
825
6ad45a27 826 if (!master->cur_msg_mapped || !master->can_dma)
99adef31
MB		 827 return 0;
828
c37f45b5
LL		 829 if (master->dma_tx)
830 tx_dev = master->dma_tx->device->dev;
831 else
832 tx_dev = &master->dev;
833
834 if (master->dma_rx)
835 rx_dev = master->dma_rx->device->dev;
836 else
837 rx_dev = &master->dev;
99adef31
MB		 838
839 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
840 if (!master->can_dma(master, msg->spi, xfer))
841 continue;
842
6ad45a27
MB		 843 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
844 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
99adef31
MB		 845 }
846
847 return 0;
848}
2de440f5
GU		 849#else /* !CONFIG_HAS_DMA */
850static inline int __spi_map_msg(struct spi_master *master,
851 struct spi_message *msg)
852{
853 return 0;
854}
855
4b786458
MS		 856static inline int __spi_unmap_msg(struct spi_master *master,
857 struct spi_message *msg)
2de440f5
GU		 858{
859 return 0;
860}
861#endif /* !CONFIG_HAS_DMA */
862
4b786458
MS		 863static inline int spi_unmap_msg(struct spi_master *master,
864 struct spi_message *msg)
865{
866 struct spi_transfer *xfer;
867
868 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
869 /*
870 * Restore the original value of tx_buf or rx_buf if they are
871 * NULL.
872 */
873 if (xfer->tx_buf == master->dummy_tx)
874 xfer->tx_buf = NULL;
875 if (xfer->rx_buf == master->dummy_rx)
876 xfer->rx_buf = NULL;
877 }
878
879 return __spi_unmap_msg(master, msg);
880}
881
2de440f5
GU		 882static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
883{
884 struct spi_transfer *xfer;
885 void *tmp;
886 unsigned int max_tx, max_rx;
887
888 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
889 max_tx = 0;
890 max_rx = 0;
891
892 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
893 if ((master->flags & SPI_MASTER_MUST_TX) &&
894 !xfer->tx_buf)
895 max_tx = max(xfer->len, max_tx);
896 if ((master->flags & SPI_MASTER_MUST_RX) &&
897 !xfer->rx_buf)
898 max_rx = max(xfer->len, max_rx);
899 }
900
901 if (max_tx) {
902 tmp = krealloc(master->dummy_tx, max_tx,
903 GFP_KERNEL | GFP_DMA);
904 if (!tmp)
905 return -ENOMEM;
906 master->dummy_tx = tmp;
907 memset(tmp, 0, max_tx);
908 }
909
910 if (max_rx) {
911 tmp = krealloc(master->dummy_rx, max_rx,
912 GFP_KERNEL | GFP_DMA);
913 if (!tmp)
914 return -ENOMEM;
915 master->dummy_rx = tmp;
916 }
917
918 if (max_tx || max_rx) {
919 list_for_each_entry(xfer, &msg->transfers,
920 transfer_list) {
921 if (!xfer->tx_buf)
922 xfer->tx_buf = master->dummy_tx;
923 if (!xfer->rx_buf)
924 xfer->rx_buf = master->dummy_rx;
925 }
926 }
927 }
928
929 return __spi_map_msg(master, msg);
930}
99adef31 931
b158935f
MB		 932/*
933 * spi_transfer_one_message - Default implementation of transfer_one_message()
934 *
935 * This is a standard implementation of transfer_one_message() for
936 * drivers which impelment a transfer_one() operation. It provides
937 * standard handling of delays and chip select management.
938 */
939static int spi_transfer_one_message(struct spi_master *master,
940 struct spi_message *msg)
941{
942 struct spi_transfer *xfer;
b158935f
MB		 943 bool keep_cs = false;
944 int ret = 0;
682a71b2 945 unsigned long ms = 1;
eca2ebc7
MS		 946 struct spi_statistics *statm = &master->statistics;
947 struct spi_statistics *stats = &msg->spi->statistics;
b158935f
MB		 948
949 spi_set_cs(msg->spi, true);
950
eca2ebc7
MS		 951 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
952 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
953
b158935f
MB		 954 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
955 trace_spi_transfer_start(msg, xfer);
956
eca2ebc7
MS		 957 spi_statistics_add_transfer_stats(statm, xfer, master);
958 spi_statistics_add_transfer_stats(stats, xfer, master);
959
38ec10f6
MB		 960 if (xfer->tx_buf || xfer->rx_buf) {
961 reinit_completion(&master->xfer_completion);
b158935f 962
38ec10f6
MB		 963 ret = master->transfer_one(master, msg->spi, xfer);
964 if (ret < 0) {
eca2ebc7
MS		 965 SPI_STATISTICS_INCREMENT_FIELD(statm,
966 errors);
967 SPI_STATISTICS_INCREMENT_FIELD(stats,
968 errors);
38ec10f6
MB		 969 dev_err(&msg->spi->dev,
970 "SPI transfer failed: %d\n", ret);
971 goto out;
972 }
b158935f 973
38ec10f6
MB		 974 if (ret > 0) {
975 ret = 0;
976 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
977 ms += ms + 100; /* some tolerance */
16a0ce4e 978
38ec10f6
MB		 979 ms = wait_for_completion_timeout(&master->xfer_completion,
980 msecs_to_jiffies(ms));
981 }
16a0ce4e 982
38ec10f6 983 if (ms == 0) {
eca2ebc7
MS		 984 SPI_STATISTICS_INCREMENT_FIELD(statm,
985 timedout);
986 SPI_STATISTICS_INCREMENT_FIELD(stats,
987 timedout);
38ec10f6
MB		 988 dev_err(&msg->spi->dev,
989 "SPI transfer timed out\n");
990 msg->status = -ETIMEDOUT;
991 }
992 } else {
993 if (xfer->len)
994 dev_err(&msg->spi->dev,
995 "Bufferless transfer has length %u\n",
996 xfer->len);
13a42798 997 }
b158935f
MB		 998
999 trace_spi_transfer_stop(msg, xfer);
1000
1001 if (msg->status != -EINPROGRESS)
1002 goto out;
1003
1004 if (xfer->delay_usecs)
1005 udelay(xfer->delay_usecs);
1006
1007 if (xfer->cs_change) {
1008 if (list_is_last(&xfer->transfer_list,
1009 &msg->transfers)) {
1010 keep_cs = true;
1011 } else {
0b73aa63
MB		 1012 spi_set_cs(msg->spi, false);
1013 udelay(10);
1014 spi_set_cs(msg->spi, true);
b158935f
MB		 1015 }
1016 }
1017
1018 msg->actual_length += xfer->len;
1019 }
1020
1021out:
1022 if (ret != 0 || !keep_cs)
1023 spi_set_cs(msg->spi, false);
1024
1025 if (msg->status == -EINPROGRESS)
1026 msg->status = ret;
1027
ff61eb42 1028 if (msg->status && master->handle_err)
b716c4ff
AS		 1029 master->handle_err(master, msg);
1030
d780c371
MS		 1031 spi_res_release(master, msg);
1032
b158935f
MB		 1033 spi_finalize_current_message(master);
1034
1035 return ret;
1036}
1037
1038/**
1039 * spi_finalize_current_transfer - report completion of a transfer
2c675689 1040 * @master: the master reporting completion
b158935f
MB		 1041 *
1042 * Called by SPI drivers using the core transfer_one_message()
1043 * implementation to notify it that the current interrupt driven
9e8f4882 1044 * transfer has finished and the next one may be scheduled.
b158935f
MB		 1045 */
1046void spi_finalize_current_transfer(struct spi_master *master)
1047{
1048 complete(&master->xfer_completion);
1049}
1050EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1051
ffbbdd21 1052/**
fc9e0f71
MB		 1053 * __spi_pump_messages - function which processes spi message queue
1054 * @master: master to process queue for
1055 * @in_kthread: true if we are in the context of the message pump thread
ffbbdd21
LW		 1056 *
1057 * This function checks if there is any spi message in the queue that
1058 * needs processing and if so call out to the driver to initialize hardware
1059 * and transfer each message.
1060 *
0461a414
MB		 1061 * Note that it is called both from the kthread itself and also from
1062 * inside spi_sync(); the queue extraction handling at the top of the
1063 * function should deal with this safely.
ffbbdd21 1064 */
fc9e0f71 1065static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
ffbbdd21 1066{
ffbbdd21
LW		 1067 unsigned long flags;
1068 bool was_busy = false;
1069 int ret;
1070
983aee5d 1071 /* Lock queue */
ffbbdd21 1072 spin_lock_irqsave(&master->queue_lock, flags);
983aee5d
MB		 1073
1074 /* Make sure we are not already running a message */
1075 if (master->cur_msg) {
1076 spin_unlock_irqrestore(&master->queue_lock, flags);
1077 return;
1078 }
1079
0461a414
MB		 1080 /* If another context is idling the device then defer */
1081 if (master->idling) {
1082 queue_kthread_work(&master->kworker, &master->pump_messages);
1083 spin_unlock_irqrestore(&master->queue_lock, flags);
1084 return;
1085 }
1086
983aee5d 1087 /* Check if the queue is idle */
ffbbdd21 1088 if (list_empty(&master->queue) || !master->running) {
b0b36b86
BF		 1089 if (!master->busy) {
1090 spin_unlock_irqrestore(&master->queue_lock, flags);
1091 return;
ffbbdd21 1092 }
fc9e0f71
MB		 1093
1094 /* Only do teardown in the thread */
1095 if (!in_kthread) {
1096 queue_kthread_work(&master->kworker,
1097 &master->pump_messages);
1098 spin_unlock_irqrestore(&master->queue_lock, flags);
1099 return;
1100 }
1101
ffbbdd21 1102 master->busy = false;
0461a414 1103 master->idling = true;
ffbbdd21 1104 spin_unlock_irqrestore(&master->queue_lock, flags);
0461a414 1105
3a2eba9b
MB		 1106 kfree(master->dummy_rx);
1107 master->dummy_rx = NULL;
1108 kfree(master->dummy_tx);
1109 master->dummy_tx = NULL;
b0b36b86
BF		 1110 if (master->unprepare_transfer_hardware &&
1111 master->unprepare_transfer_hardware(master))
1112 dev_err(&master->dev,
1113 "failed to unprepare transfer hardware\n");
49834de2
MB		 1114 if (master->auto_runtime_pm) {
1115 pm_runtime_mark_last_busy(master->dev.parent);
1116 pm_runtime_put_autosuspend(master->dev.parent);
1117 }
56ec1978 1118 trace_spi_master_idle(master);
ffbbdd21 1119
0461a414
MB		 1120 spin_lock_irqsave(&master->queue_lock, flags);
1121 master->idling = false;
ffbbdd21
LW		 1122 spin_unlock_irqrestore(&master->queue_lock, flags);
1123 return;
1124 }
ffbbdd21 1125
ffbbdd21
LW		 1126 /* Extract head of queue */
1127 master->cur_msg =
a89e2d27 1128 list_first_entry(&master->queue, struct spi_message, queue);
ffbbdd21
LW		 1129
1130 list_del_init(&master->cur_msg->queue);
1131 if (master->busy)
1132 was_busy = true;
1133 else
1134 master->busy = true;
1135 spin_unlock_irqrestore(&master->queue_lock, flags);
1136
49834de2
MB		 1137 if (!was_busy && master->auto_runtime_pm) {
1138 ret = pm_runtime_get_sync(master->dev.parent);
1139 if (ret < 0) {
1140 dev_err(&master->dev, "Failed to power device: %d\n",
1141 ret);
1142 return;
1143 }
1144 }
1145
56ec1978
MB		 1146 if (!was_busy)
1147 trace_spi_master_busy(master);
1148
7dfd2bd7 1149 if (!was_busy && master->prepare_transfer_hardware) {
ffbbdd21
LW		 1150 ret = master->prepare_transfer_hardware(master);
1151 if (ret) {
1152 dev_err(&master->dev,
1153 "failed to prepare transfer hardware\n");
49834de2
MB		 1154
1155 if (master->auto_runtime_pm)
1156 pm_runtime_put(master->dev.parent);
ffbbdd21
LW		 1157 return;
1158 }
1159 }
1160
56ec1978
MB		 1161 trace_spi_message_start(master->cur_msg);
1162
2841a5fc
MB		 1163 if (master->prepare_message) {
1164 ret = master->prepare_message(master, master->cur_msg);
1165 if (ret) {
1166 dev_err(&master->dev,
1167 "failed to prepare message: %d\n", ret);
1168 master->cur_msg->status = ret;
1169 spi_finalize_current_message(master);
1170 return;
1171 }
1172 master->cur_msg_prepared = true;
1173 }
1174
99adef31
MB		 1175 ret = spi_map_msg(master, master->cur_msg);
1176 if (ret) {
1177 master->cur_msg->status = ret;
1178 spi_finalize_current_message(master);
1179 return;
1180 }
1181
ffbbdd21
LW		 1182 ret = master->transfer_one_message(master, master->cur_msg);
1183 if (ret) {
1184 dev_err(&master->dev,
1f802f82 1185 "failed to transfer one message from queue\n");
ffbbdd21
LW		 1186 return;
1187 }
1188}
1189
fc9e0f71
MB		 1190/**
1191 * spi_pump_messages - kthread work function which processes spi message queue
1192 * @work: pointer to kthread work struct contained in the master struct
1193 */
1194static void spi_pump_messages(struct kthread_work *work)
1195{
1196 struct spi_master *master =
1197 container_of(work, struct spi_master, pump_messages);
1198
1199 __spi_pump_messages(master, true);
1200}
1201
ffbbdd21
LW		 1202static int spi_init_queue(struct spi_master *master)
1203{
1204 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1205
ffbbdd21
LW		 1206 master->running = false;
1207 master->busy = false;
1208
1209 init_kthread_worker(&master->kworker);
1210 master->kworker_task = kthread_run(kthread_worker_fn,
f170168b 1211 &master->kworker, "%s",
ffbbdd21
LW		 1212 dev_name(&master->dev));
1213 if (IS_ERR(master->kworker_task)) {
1214 dev_err(&master->dev, "failed to create message pump task\n");
98a8f5a0 1215 return PTR_ERR(master->kworker_task);
ffbbdd21
LW		 1216 }
1217 init_kthread_work(&master->pump_messages, spi_pump_messages);
1218
1219 /*
1220 * Master config will indicate if this controller should run the
1221 * message pump with high (realtime) priority to reduce the transfer
1222 * latency on the bus by minimising the delay between a transfer
1223 * request and the scheduling of the message pump thread. Without this
1224 * setting the message pump thread will remain at default priority.
1225 */
1226 if (master->rt) {
1227 dev_info(&master->dev,
1228 "will run message pump with realtime priority\n");
1229 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1230 }
1231
1232 return 0;
1233}
1234
1235/**
1236 * spi_get_next_queued_message() - called by driver to check for queued
1237 * messages
1238 * @master: the master to check for queued messages
1239 *
1240 * If there are more messages in the queue, the next message is returned from
1241 * this call.
97d56dc6
JMC		 1242 *
1243 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21
LW		 1244 */
1245struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1246{
1247 struct spi_message *next;
1248 unsigned long flags;
1249
1250 /* get a pointer to the next message, if any */
1251 spin_lock_irqsave(&master->queue_lock, flags);
1cfd97f9
AL		 1252 next = list_first_entry_or_null(&master->queue, struct spi_message,
1253 queue);
ffbbdd21
LW		 1254 spin_unlock_irqrestore(&master->queue_lock, flags);
1255
1256 return next;
1257}
1258EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1259
1260/**
1261 * spi_finalize_current_message() - the current message is complete
1262 * @master: the master to return the message to
1263 *
1264 * Called by the driver to notify the core that the message in the front of the
1265 * queue is complete and can be removed from the queue.
1266 */
1267void spi_finalize_current_message(struct spi_master *master)
1268{
1269 struct spi_message *mesg;
1270 unsigned long flags;
2841a5fc 1271 int ret;
ffbbdd21
LW		 1272
1273 spin_lock_irqsave(&master->queue_lock, flags);
1274 mesg = master->cur_msg;
ffbbdd21
LW		 1275 spin_unlock_irqrestore(&master->queue_lock, flags);
1276
99adef31
MB		 1277 spi_unmap_msg(master, mesg);
1278
2841a5fc
MB		 1279 if (master->cur_msg_prepared && master->unprepare_message) {
1280 ret = master->unprepare_message(master, mesg);
1281 if (ret) {
1282 dev_err(&master->dev,
1283 "failed to unprepare message: %d\n", ret);
1284 }
1285 }
391949b6 1286
8e76ef88
MS		 1287 spin_lock_irqsave(&master->queue_lock, flags);
1288 master->cur_msg = NULL;
2841a5fc 1289 master->cur_msg_prepared = false;
8e76ef88
MS		 1290 queue_kthread_work(&master->kworker, &master->pump_messages);
1291 spin_unlock_irqrestore(&master->queue_lock, flags);
1292
1293 trace_spi_message_done(mesg);
2841a5fc 1294
ffbbdd21
LW		 1295 mesg->state = NULL;
1296 if (mesg->complete)
1297 mesg->complete(mesg->context);
1298}
1299EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1300
1301static int spi_start_queue(struct spi_master *master)
1302{
1303 unsigned long flags;
1304
1305 spin_lock_irqsave(&master->queue_lock, flags);
1306
1307 if (master->running || master->busy) {
1308 spin_unlock_irqrestore(&master->queue_lock, flags);
1309 return -EBUSY;
1310 }
1311
1312 master->running = true;
1313 master->cur_msg = NULL;
1314 spin_unlock_irqrestore(&master->queue_lock, flags);
1315
1316 queue_kthread_work(&master->kworker, &master->pump_messages);
1317
1318 return 0;
1319}
1320
1321static int spi_stop_queue(struct spi_master *master)
1322{
1323 unsigned long flags;
1324 unsigned limit = 500;
1325 int ret = 0;
1326
1327 spin_lock_irqsave(&master->queue_lock, flags);
1328
1329 /*
1330 * This is a bit lame, but is optimized for the common execution path.
1331 * A wait_queue on the master->busy could be used, but then the common
1332 * execution path (pump_messages) would be required to call wake_up or
1333 * friends on every SPI message. Do this instead.
1334 */
1335 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1336 spin_unlock_irqrestore(&master->queue_lock, flags);
f97b26b0 1337 usleep_range(10000, 11000);
ffbbdd21
LW		 1338 spin_lock_irqsave(&master->queue_lock, flags);
1339 }
1340
1341 if (!list_empty(&master->queue) || master->busy)
1342 ret = -EBUSY;
1343 else
1344 master->running = false;
1345
1346 spin_unlock_irqrestore(&master->queue_lock, flags);
1347
1348 if (ret) {
1349 dev_warn(&master->dev,
1350 "could not stop message queue\n");
1351 return ret;
1352 }
1353 return ret;
1354}
1355
1356static int spi_destroy_queue(struct spi_master *master)
1357{
1358 int ret;
1359
1360 ret = spi_stop_queue(master);
1361
1362 /*
1363 * flush_kthread_worker will block until all work is done.
1364 * If the reason that stop_queue timed out is that the work will never
1365 * finish, then it does no good to call flush/stop thread, so
1366 * return anyway.
1367 */
1368 if (ret) {
1369 dev_err(&master->dev, "problem destroying queue\n");
1370 return ret;
1371 }
1372
1373 flush_kthread_worker(&master->kworker);
1374 kthread_stop(master->kworker_task);
1375
1376 return 0;
1377}
1378
0461a414
MB		 1379static int __spi_queued_transfer(struct spi_device *spi,
1380 struct spi_message *msg,
1381 bool need_pump)
ffbbdd21
LW		 1382{
1383 struct spi_master *master = spi->master;
1384 unsigned long flags;
1385
1386 spin_lock_irqsave(&master->queue_lock, flags);
1387
1388 if (!master->running) {
1389 spin_unlock_irqrestore(&master->queue_lock, flags);
1390 return -ESHUTDOWN;
1391 }
1392 msg->actual_length = 0;
1393 msg->status = -EINPROGRESS;
1394
1395 list_add_tail(&msg->queue, &master->queue);
0461a414 1396 if (!master->busy && need_pump)
ffbbdd21
LW		 1397 queue_kthread_work(&master->kworker, &master->pump_messages);
1398
1399 spin_unlock_irqrestore(&master->queue_lock, flags);
1400 return 0;
1401}
1402
0461a414
MB		 1403/**
1404 * spi_queued_transfer - transfer function for queued transfers
1405 * @spi: spi device which is requesting transfer
1406 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1407 *
1408 * Return: zero on success, else a negative error code.
0461a414
MB		 1409 */
1410static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1411{
1412 return __spi_queued_transfer(spi, msg, true);
1413}
1414
ffbbdd21
LW		 1415static int spi_master_initialize_queue(struct spi_master *master)
1416{
1417 int ret;
1418
ffbbdd21 1419 master->transfer = spi_queued_transfer;
b158935f
MB		 1420 if (!master->transfer_one_message)
1421 master->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1422
1423 /* Initialize and start queue */
1424 ret = spi_init_queue(master);
1425 if (ret) {
1426 dev_err(&master->dev, "problem initializing queue\n");
1427 goto err_init_queue;
1428 }
c3676d5c 1429 master->queued = true;
ffbbdd21
LW		 1430 ret = spi_start_queue(master);
1431 if (ret) {
1432 dev_err(&master->dev, "problem starting queue\n");
1433 goto err_start_queue;
1434 }
1435
1436 return 0;
1437
1438err_start_queue:
ffbbdd21 1439 spi_destroy_queue(master);
c3676d5c 1440err_init_queue:
ffbbdd21
LW		 1441 return ret;
1442}
1443
1444/*-------------------------------------------------------------------------*/
1445
7cb94361 1446#if defined(CONFIG_OF)
aff5e3f8
PA		 1447static struct spi_device *
1448of_register_spi_device(struct spi_master *master, struct device_node *nc)
1449{
1450 struct spi_device *spi;
1451 int rc;
1452 u32 value;
1453
1454 /* Alloc an spi_device */
1455 spi = spi_alloc_device(master);
1456 if (!spi) {
1457 dev_err(&master->dev, "spi_device alloc error for %s\n",
1458 nc->full_name);
1459 rc = -ENOMEM;
1460 goto err_out;
1461 }
1462
1463 /* Select device driver */
1464 rc = of_modalias_node(nc, spi->modalias,
1465 sizeof(spi->modalias));
1466 if (rc < 0) {
1467 dev_err(&master->dev, "cannot find modalias for %s\n",
1468 nc->full_name);
1469 goto err_out;
1470 }
1471
1472 /* Device address */
1473 rc = of_property_read_u32(nc, "reg", &value);
1474 if (rc) {
1475 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1476 nc->full_name, rc);
1477 goto err_out;
1478 }
1479 spi->chip_select = value;
1480
1481 /* Mode (clock phase/polarity/etc.) */
1482 if (of_find_property(nc, "spi-cpha", NULL))
1483 spi->mode |= SPI_CPHA;
1484 if (of_find_property(nc, "spi-cpol", NULL))
1485 spi->mode |= SPI_CPOL;
1486 if (of_find_property(nc, "spi-cs-high", NULL))
1487 spi->mode |= SPI_CS_HIGH;
1488 if (of_find_property(nc, "spi-3wire", NULL))
1489 spi->mode |= SPI_3WIRE;
1490 if (of_find_property(nc, "spi-lsb-first", NULL))
1491 spi->mode |= SPI_LSB_FIRST;
1492
1493 /* Device DUAL/QUAD mode */
1494 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1495 switch (value) {
1496 case 1:
1497 break;
1498 case 2:
1499 spi->mode |= SPI_TX_DUAL;
1500 break;
1501 case 4:
1502 spi->mode |= SPI_TX_QUAD;
1503 break;
1504 default:
1505 dev_warn(&master->dev,
1506 "spi-tx-bus-width %d not supported\n",
1507 value);
1508 break;
1509 }
1510 }
1511
1512 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1513 switch (value) {
1514 case 1:
1515 break;
1516 case 2:
1517 spi->mode |= SPI_RX_DUAL;
1518 break;
1519 case 4:
1520 spi->mode |= SPI_RX_QUAD;
1521 break;
1522 default:
1523 dev_warn(&master->dev,
1524 "spi-rx-bus-width %d not supported\n",
1525 value);
1526 break;
1527 }
1528 }
1529
1530 /* Device speed */
1531 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1532 if (rc) {
1533 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1534 nc->full_name, rc);
1535 goto err_out;
1536 }
1537 spi->max_speed_hz = value;
1538
aff5e3f8
PA		 1539 /* Store a pointer to the node in the device structure */
1540 of_node_get(nc);
1541 spi->dev.of_node = nc;
1542
1543 /* Register the new device */
aff5e3f8
PA		 1544 rc = spi_add_device(spi);
1545 if (rc) {
1546 dev_err(&master->dev, "spi_device register error %s\n",
1547 nc->full_name);
1548 goto err_out;
1549 }
1550
1551 return spi;
1552
1553err_out:
1554 spi_dev_put(spi);
1555 return ERR_PTR(rc);
1556}
1557
d57a4282
GL		 1558/**
1559 * of_register_spi_devices() - Register child devices onto the SPI bus
1560 * @master: Pointer to spi_master device
1561 *
1562 * Registers an spi_device for each child node of master node which has a 'reg'
1563 * property.
1564 */
1565static void of_register_spi_devices(struct spi_master *master)
1566{
1567 struct spi_device *spi;
1568 struct device_node *nc;
d57a4282
GL		 1569
1570 if (!master->dev.of_node)
1571 return;
1572
f3b6159e 1573 for_each_available_child_of_node(master->dev.of_node, nc) {
bd6c1644
GU		 1574 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1575 continue;
aff5e3f8
PA		 1576 spi = of_register_spi_device(master, nc);
1577 if (IS_ERR(spi))
1578 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
d57a4282 1579 nc->full_name);
d57a4282
GL		 1580 }
1581}
1582#else
1583static void of_register_spi_devices(struct spi_master *master) { }
1584#endif
1585
64bee4d2
MW		 1586#ifdef CONFIG_ACPI
1587static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1588{
1589 struct spi_device *spi = data;
1590
1591 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1592 struct acpi_resource_spi_serialbus *sb;
1593
1594 sb = &ares->data.spi_serial_bus;
1595 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1596 spi->chip_select = sb->device_selection;
1597 spi->max_speed_hz = sb->connection_speed;
1598
1599 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1600 spi->mode |= SPI_CPHA;
1601 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1602 spi->mode |= SPI_CPOL;
1603 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1604 spi->mode |= SPI_CS_HIGH;
1605 }
1606 } else if (spi->irq < 0) {
1607 struct resource r;
1608
1609 if (acpi_dev_resource_interrupt(ares, 0, &r))
1610 spi->irq = r.start;
1611 }
1612
1613 /* Always tell the ACPI core to skip this resource */
1614 return 1;
1615}
1616
1617static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1618 void *data, void **return_value)
1619{
1620 struct spi_master *master = data;
1621 struct list_head resource_list;
1622 struct acpi_device *adev;
1623 struct spi_device *spi;
1624 int ret;
1625
1626 if (acpi_bus_get_device(handle, &adev))
1627 return AE_OK;
1628 if (acpi_bus_get_status(adev) || !adev->status.present)
1629 return AE_OK;
1630
1631 spi = spi_alloc_device(master);
1632 if (!spi) {
1633 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1634 dev_name(&adev->dev));
1635 return AE_NO_MEMORY;
1636 }
1637
7b199811 1638 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1639 spi->irq = -1;
1640
1641 INIT_LIST_HEAD(&resource_list);
1642 ret = acpi_dev_get_resources(adev, &resource_list,
1643 acpi_spi_add_resource, spi);
1644 acpi_dev_free_resource_list(&resource_list);
1645
1646 if (ret < 0 || !spi->max_speed_hz) {
1647 spi_dev_put(spi);
1648 return AE_OK;
1649 }
1650
33ada67d
CR		 1651 if (spi->irq < 0)
1652 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1653
33cf00e5 1654 adev->power.flags.ignore_parent = true;
cf9eb39c 1655 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
64bee4d2 1656 if (spi_add_device(spi)) {
33cf00e5 1657 adev->power.flags.ignore_parent = false;
64bee4d2
MW		 1658 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1659 dev_name(&adev->dev));
1660 spi_dev_put(spi);
1661 }
1662
1663 return AE_OK;
1664}
1665
1666static void acpi_register_spi_devices(struct spi_master *master)
1667{
1668 acpi_status status;
1669 acpi_handle handle;
1670
29896178 1671 handle = ACPI_HANDLE(master->dev.parent);
64bee4d2
MW		 1672 if (!handle)
1673 return;
1674
1675 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1676 acpi_spi_add_device, NULL,
1677 master, NULL);
1678 if (ACPI_FAILURE(status))
1679 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1680}
1681#else
1682static inline void acpi_register_spi_devices(struct spi_master *master) {}
1683#endif /* CONFIG_ACPI */
1684
49dce689 1685static void spi_master_release(struct device *dev)
8ae12a0d
DB		 1686{
1687 struct spi_master *master;
1688
49dce689 1689 master = container_of(dev, struct spi_master, dev);
8ae12a0d
DB		 1690 kfree(master);
1691}
1692
1693static struct class spi_master_class = {
1694 .name = "spi_master",
1695 .owner = THIS_MODULE,
49dce689 1696 .dev_release = spi_master_release,
eca2ebc7 1697 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1698};
1699
1700
1701/**
1702 * spi_alloc_master - allocate SPI master controller
1703 * @dev: the controller, possibly using the platform_bus
33e34dc6 1704 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 1705 * memory is in the driver_data field of the returned device,
0c868461 1706 * accessible with spi_master_get_devdata().
33e34dc6 1707 * Context: can sleep
8ae12a0d
DB		 1708 *
1709 * This call is used only by SPI master controller drivers, which are the
1710 * only ones directly touching chip registers. It's how they allocate
ba1a0513 1711 * an spi_master structure, prior to calling spi_register_master().
8ae12a0d 1712 *
97d56dc6 1713 * This must be called from context that can sleep.
8ae12a0d
DB		 1714 *
1715 * The caller is responsible for assigning the bus number and initializing
ba1a0513 1716 * the master's methods before calling spi_register_master(); and (after errors
a394d635 1717 * adding the device) calling spi_master_put() to prevent a memory leak.
97d56dc6
JMC		 1718 *
1719 * Return: the SPI master structure on success, else NULL.
8ae12a0d 1720 */
e9d5a461 1721struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
8ae12a0d
DB		 1722{
1723 struct spi_master *master;
1724
0c868461
DB		 1725 if (!dev)
1726 return NULL;
1727
5fe5f05e 1728 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
8ae12a0d
DB		 1729 if (!master)
1730 return NULL;
1731
49dce689 1732 device_initialize(&master->dev);
1e8a52e1
GL		 1733 master->bus_num = -1;
1734 master->num_chipselect = 1;
49dce689 1735 master->dev.class = &spi_master_class;
157f38f9 1736 master->dev.parent = dev;
0c868461 1737 spi_master_set_devdata(master, &master[1]);
8ae12a0d
DB		 1738
1739 return master;
1740}
1741EXPORT_SYMBOL_GPL(spi_alloc_master);
1742
74317984
JCPV		 1743#ifdef CONFIG_OF
1744static int of_spi_register_master(struct spi_master *master)
1745{
e80beb27 1746 int nb, i, *cs;
74317984
JCPV		 1747 struct device_node *np = master->dev.of_node;
1748
1749 if (!np)
1750 return 0;
1751
1752 nb = of_gpio_named_count(np, "cs-gpios");
5fe5f05e 1753 master->num_chipselect = max_t(int, nb, master->num_chipselect);
74317984 1754
8ec5d84e
AL		 1755 /* Return error only for an incorrectly formed cs-gpios property */
1756 if (nb == 0 || nb == -ENOENT)
74317984 1757 return 0;
8ec5d84e
AL		 1758 else if (nb < 0)
1759 return nb;
74317984
JCPV		 1760
1761 cs = devm_kzalloc(&master->dev,
1762 sizeof(int) * master->num_chipselect,
1763 GFP_KERNEL);
1764 master->cs_gpios = cs;
1765
1766 if (!master->cs_gpios)
1767 return -ENOMEM;
1768
0da83bb1 1769 for (i = 0; i < master->num_chipselect; i++)
446411e1 1770 cs[i] = -ENOENT;
74317984
JCPV		 1771
1772 for (i = 0; i < nb; i++)
1773 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1774
1775 return 0;
1776}
1777#else
1778static int of_spi_register_master(struct spi_master *master)
1779{
1780 return 0;
1781}
1782#endif
1783
8ae12a0d
DB		 1784/**
1785 * spi_register_master - register SPI master controller
1786 * @master: initialized master, originally from spi_alloc_master()
33e34dc6 1787 * Context: can sleep
8ae12a0d
DB		 1788 *
1789 * SPI master controllers connect to their drivers using some non-SPI bus,
1790 * such as the platform bus. The final stage of probe() in that code
1791 * includes calling spi_register_master() to hook up to this SPI bus glue.
1792 *
1793 * SPI controllers use board specific (often SOC specific) bus numbers,
1794 * and board-specific addressing for SPI devices combines those numbers
1795 * with chip select numbers. Since SPI does not directly support dynamic
1796 * device identification, boards need configuration tables telling which
1797 * chip is at which address.
1798 *
1799 * This must be called from context that can sleep. It returns zero on
1800 * success, else a negative error code (dropping the master's refcount).
0c868461
DB		 1801 * After a successful return, the caller is responsible for calling
1802 * spi_unregister_master().
97d56dc6
JMC		 1803 *
1804 * Return: zero on success, else a negative error code.
8ae12a0d 1805 */
e9d5a461 1806int spi_register_master(struct spi_master *master)
8ae12a0d 1807{
e44a45ae 1808 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
49dce689 1809 struct device *dev = master->dev.parent;
2b9603a0 1810 struct boardinfo *bi;
8ae12a0d
DB		 1811 int status = -ENODEV;
1812 int dynamic = 0;
1813
0c868461
DB		 1814 if (!dev)
1815 return -ENODEV;
1816
74317984
JCPV		 1817 status = of_spi_register_master(master);
1818 if (status)
1819 return status;
1820
082c8cb4
DB		 1821 /* even if it's just one always-selected device, there must
1822 * be at least one chipselect
1823 */
1824 if (master->num_chipselect == 0)
1825 return -EINVAL;
1826
bb29785e
GL		 1827 if ((master->bus_num < 0) && master->dev.of_node)
1828 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1829
8ae12a0d 1830 /* convention: dynamically assigned bus IDs count down from the max */
a020ed75 1831 if (master->bus_num < 0) {
082c8cb4
DB		 1832 /* FIXME switch to an IDR based scheme, something like
1833 * I2C now uses, so we can't run out of "dynamic" IDs
1834 */
8ae12a0d 1835 master->bus_num = atomic_dec_return(&dyn_bus_id);
b885244e 1836 dynamic = 1;
8ae12a0d
DB		 1837 }
1838
5424d43e
MB		 1839 INIT_LIST_HEAD(&master->queue);
1840 spin_lock_init(&master->queue_lock);
cf32b71e
ES		 1841 spin_lock_init(&master->bus_lock_spinlock);
1842 mutex_init(&master->bus_lock_mutex);
1843 master->bus_lock_flag = 0;
b158935f 1844 init_completion(&master->xfer_completion);
6ad45a27
MB		 1845 if (!master->max_dma_len)
1846 master->max_dma_len = INT_MAX;
cf32b71e 1847
8ae12a0d
DB		 1848 /* register the device, then userspace will see it.
1849 * registration fails if the bus ID is in use.
1850 */
35f74fca 1851 dev_set_name(&master->dev, "spi%u", master->bus_num);
49dce689 1852 status = device_add(&master->dev);
b885244e 1853 if (status < 0)
8ae12a0d 1854 goto done;
35f74fca 1855 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
8ae12a0d
DB		 1856 dynamic ? " (dynamic)" : "");
1857
ffbbdd21
LW		 1858 /* If we're using a queued driver, start the queue */
1859 if (master->transfer)
1860 dev_info(dev, "master is unqueued, this is deprecated\n");
1861 else {
1862 status = spi_master_initialize_queue(master);
1863 if (status) {
e93b0724 1864 device_del(&master->dev);
ffbbdd21
LW		 1865 goto done;
1866 }
1867 }
eca2ebc7
MS		 1868 /* add statistics */
1869 spin_lock_init(&master->statistics.lock);
ffbbdd21 1870
2b9603a0
FT		 1871 mutex_lock(&board_lock);
1872 list_add_tail(&master->list, &spi_master_list);
1873 list_for_each_entry(bi, &board_list, list)
1874 spi_match_master_to_boardinfo(master, &bi->board_info);
1875 mutex_unlock(&board_lock);
1876
64bee4d2 1877 /* Register devices from the device tree and ACPI */
12b15e83 1878 of_register_spi_devices(master);
64bee4d2 1879 acpi_register_spi_devices(master);
8ae12a0d
DB		 1880done:
1881 return status;
1882}
1883EXPORT_SYMBOL_GPL(spi_register_master);
1884
666d5b4c
MB		 1885static void devm_spi_unregister(struct device *dev, void *res)
1886{
1887 spi_unregister_master(*(struct spi_master **)res);
1888}
1889
1890/**
1891 * dev_spi_register_master - register managed SPI master controller
1892 * @dev: device managing SPI master
1893 * @master: initialized master, originally from spi_alloc_master()
1894 * Context: can sleep
1895 *
1896 * Register a SPI device as with spi_register_master() which will
1897 * automatically be unregister
97d56dc6
JMC		 1898 *
1899 * Return: zero on success, else a negative error code.
666d5b4c
MB		 1900 */
1901int devm_spi_register_master(struct device *dev, struct spi_master *master)
1902{
1903 struct spi_master **ptr;
1904 int ret;
1905
1906 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1907 if (!ptr)
1908 return -ENOMEM;
1909
1910 ret = spi_register_master(master);
4b92894e 1911 if (!ret) {
666d5b4c
MB		 1912 *ptr = master;
1913 devres_add(dev, ptr);
1914 } else {
1915 devres_free(ptr);
1916 }
1917
1918 return ret;
1919}
1920EXPORT_SYMBOL_GPL(devm_spi_register_master);
1921
34860089 1922static int __unregister(struct device *dev, void *null)
8ae12a0d 1923{
34860089 1924 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 1925 return 0;
1926}
1927
1928/**
1929 * spi_unregister_master - unregister SPI master controller
1930 * @master: the master being unregistered
33e34dc6 1931 * Context: can sleep
8ae12a0d
DB		 1932 *
1933 * This call is used only by SPI master controller drivers, which are the
1934 * only ones directly touching chip registers.
1935 *
1936 * This must be called from context that can sleep.
1937 */
1938void spi_unregister_master(struct spi_master *master)
1939{
89fc9a1a
JG		 1940 int dummy;
1941
ffbbdd21
LW		 1942 if (master->queued) {
1943 if (spi_destroy_queue(master))
1944 dev_err(&master->dev, "queue remove failed\n");
1945 }
1946
2b9603a0
FT		 1947 mutex_lock(&board_lock);
1948 list_del(&master->list);
1949 mutex_unlock(&board_lock);
1950
97dbf37d 1951 dummy = device_for_each_child(&master->dev, NULL, __unregister);
49dce689 1952 device_unregister(&master->dev);
8ae12a0d
DB		 1953}
1954EXPORT_SYMBOL_GPL(spi_unregister_master);
1955
ffbbdd21
LW		 1956int spi_master_suspend(struct spi_master *master)
1957{
1958 int ret;
1959
1960 /* Basically no-ops for non-queued masters */
1961 if (!master->queued)
1962 return 0;
1963
1964 ret = spi_stop_queue(master);
1965 if (ret)
1966 dev_err(&master->dev, "queue stop failed\n");
1967
1968 return ret;
1969}
1970EXPORT_SYMBOL_GPL(spi_master_suspend);
1971
1972int spi_master_resume(struct spi_master *master)
1973{
1974 int ret;
1975
1976 if (!master->queued)
1977 return 0;
1978
1979 ret = spi_start_queue(master);
1980 if (ret)
1981 dev_err(&master->dev, "queue restart failed\n");
1982
1983 return ret;
1984}
1985EXPORT_SYMBOL_GPL(spi_master_resume);
1986
9f3b795a 1987static int __spi_master_match(struct device *dev, const void *data)
5ed2c832
DY		 1988{
1989 struct spi_master *m;
9f3b795a 1990 const u16 *bus_num = data;
5ed2c832
DY		 1991
1992 m = container_of(dev, struct spi_master, dev);
1993 return m->bus_num == *bus_num;
1994}
1995
8ae12a0d
DB		 1996/**
1997 * spi_busnum_to_master - look up master associated with bus_num
1998 * @bus_num: the master's bus number
33e34dc6 1999 * Context: can sleep
8ae12a0d
DB		 2000 *
2001 * This call may be used with devices that are registered after
2002 * arch init time. It returns a refcounted pointer to the relevant
2003 * spi_master (which the caller must release), or NULL if there is
2004 * no such master registered.
97d56dc6
JMC		 2005 *
2006 * Return: the SPI master structure on success, else NULL.
8ae12a0d
DB		 2007 */
2008struct spi_master *spi_busnum_to_master(u16 bus_num)
2009{
49dce689 2010 struct device *dev;
1e9a51dc 2011 struct spi_master *master = NULL;
5ed2c832 2012
695794ae 2013 dev = class_find_device(&spi_master_class, NULL, &bus_num,
5ed2c832
DY		 2014 __spi_master_match);
2015 if (dev)
2016 master = container_of(dev, struct spi_master, dev);
2017 /* reference got in class_find_device */
1e9a51dc 2018 return master;
8ae12a0d
DB		 2019}
2020EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2021
d780c371
MS		 2022/*-------------------------------------------------------------------------*/
2023
2024/* Core methods for SPI resource management */
2025
2026/**
2027 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2028 * during the processing of a spi_message while using
2029 * spi_transfer_one
2030 * @spi: the spi device for which we allocate memory
2031 * @release: the release code to execute for this resource
2032 * @size: size to alloc and return
2033 * @gfp: GFP allocation flags
2034 *
2035 * Return: the pointer to the allocated data
2036 *
2037 * This may get enhanced in the future to allocate from a memory pool
2038 * of the @spi_device or @spi_master to avoid repeated allocations.
2039 */
2040void *spi_res_alloc(struct spi_device *spi,
2041 spi_res_release_t release,
2042 size_t size, gfp_t gfp)
2043{
2044 struct spi_res *sres;
2045
2046 sres = kzalloc(sizeof(*sres) + size, gfp);
2047 if (!sres)
2048 return NULL;
2049
2050 INIT_LIST_HEAD(&sres->entry);
2051 sres->release = release;
2052
2053 return sres->data;
2054}
2055EXPORT_SYMBOL_GPL(spi_res_alloc);
2056
2057/**
2058 * spi_res_free - free an spi resource
2059 * @res: pointer to the custom data of a resource
2060 *
2061 */
2062void spi_res_free(void *res)
2063{
2064 struct spi_res *sres = container_of(res, struct spi_res, data);
2065
2066 if (!res)
2067 return;
2068
2069 WARN_ON(!list_empty(&sres->entry));
2070 kfree(sres);
2071}
2072EXPORT_SYMBOL_GPL(spi_res_free);
2073
2074/**
2075 * spi_res_add - add a spi_res to the spi_message
2076 * @message: the spi message
2077 * @res: the spi_resource
2078 */
2079void spi_res_add(struct spi_message *message, void *res)
2080{
2081 struct spi_res *sres = container_of(res, struct spi_res, data);
2082
2083 WARN_ON(!list_empty(&sres->entry));
2084 list_add_tail(&sres->entry, &message->resources);
2085}
2086EXPORT_SYMBOL_GPL(spi_res_add);
2087
2088/**
2089 * spi_res_release - release all spi resources for this message
2090 * @master: the @spi_master
2091 * @message: the @spi_message
2092 */
2093void spi_res_release(struct spi_master *master,
2094 struct spi_message *message)
2095{
2096 struct spi_res *res;
2097
2098 while (!list_empty(&message->resources)) {
2099 res = list_last_entry(&message->resources,
2100 struct spi_res, entry);
2101
2102 if (res->release)
2103 res->release(master, message, res->data);
2104
2105 list_del(&res->entry);
2106
2107 kfree(res);
2108 }
2109}
2110EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2111
2112/*-------------------------------------------------------------------------*/
2113
523baf5a
MS		 2114/* Core methods for spi_message alterations */
2115
2116static void __spi_replace_transfers_release(struct spi_master *master,
2117 struct spi_message *msg,
2118 void *res)
2119{
2120 struct spi_replaced_transfers *rxfer = res;
2121 size_t i;
2122
2123 /* call extra callback if requested */
2124 if (rxfer->release)
2125 rxfer->release(master, msg, res);
2126
2127 /* insert replaced transfers back into the message */
2128 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2129
2130 /* remove the formerly inserted entries */
2131 for (i = 0; i < rxfer->inserted; i++)
2132 list_del(&rxfer->inserted_transfers[i].transfer_list);
2133}
2134
2135/**
2136 * spi_replace_transfers - replace transfers with several transfers
2137 * and register change with spi_message.resources
2138 * @msg: the spi_message we work upon
2139 * @xfer_first: the first spi_transfer we want to replace
2140 * @remove: number of transfers to remove
2141 * @insert: the number of transfers we want to insert instead
2142 * @release: extra release code necessary in some circumstances
2143 * @extradatasize: extra data to allocate (with alignment guarantees
2144 * of struct @spi_transfer)
2145 *
2146 * Returns: pointer to @spi_replaced_transfers,
2147 * PTR_ERR(...) in case of errors.
2148 */
2149struct spi_replaced_transfers *spi_replace_transfers(
2150 struct spi_message *msg,
2151 struct spi_transfer *xfer_first,
2152 size_t remove,
2153 size_t insert,
2154 spi_replaced_release_t release,
2155 size_t extradatasize,
2156 gfp_t gfp)
2157{
2158 struct spi_replaced_transfers *rxfer;
2159 struct spi_transfer *xfer;
2160 size_t i;
2161
2162 /* allocate the structure using spi_res */
2163 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2164 insert * sizeof(struct spi_transfer)
2165 + sizeof(struct spi_replaced_transfers)
2166 + extradatasize,
2167 gfp);
2168 if (!rxfer)
2169 return ERR_PTR(-ENOMEM);
2170
2171 /* the release code to invoke before running the generic release */
2172 rxfer->release = release;
2173
2174 /* assign extradata */
2175 if (extradatasize)
2176 rxfer->extradata =
2177 &rxfer->inserted_transfers[insert];
2178
2179 /* init the replaced_transfers list */
2180 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2181
2182 /* assign the list_entry after which we should reinsert
2183 * the @replaced_transfers - it may be spi_message.messages!
2184 */
2185 rxfer->replaced_after = xfer_first->transfer_list.prev;
2186
2187 /* remove the requested number of transfers */
2188 for (i = 0; i < remove; i++) {
2189 /* if the entry after replaced_after it is msg->transfers
2190 * then we have been requested to remove more transfers
2191 * than are in the list
2192 */
2193 if (rxfer->replaced_after->next == &msg->transfers) {
2194 dev_err(&msg->spi->dev,
2195 "requested to remove more spi_transfers than are available\n");
2196 /* insert replaced transfers back into the message */
2197 list_splice(&rxfer->replaced_transfers,
2198 rxfer->replaced_after);
2199
2200 /* free the spi_replace_transfer structure */
2201 spi_res_free(rxfer);
2202
2203 /* and return with an error */
2204 return ERR_PTR(-EINVAL);
2205 }
2206
2207 /* remove the entry after replaced_after from list of
2208 * transfers and add it to list of replaced_transfers
2209 */
2210 list_move_tail(rxfer->replaced_after->next,
2211 &rxfer->replaced_transfers);
2212 }
2213
2214 /* create copy of the given xfer with identical settings
2215 * based on the first transfer to get removed
2216 */
2217 for (i = 0; i < insert; i++) {
2218 /* we need to run in reverse order */
2219 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2220
2221 /* copy all spi_transfer data */
2222 memcpy(xfer, xfer_first, sizeof(*xfer));
2223
2224 /* add to list */
2225 list_add(&xfer->transfer_list, rxfer->replaced_after);
2226
2227 /* clear cs_change and delay_usecs for all but the last */
2228 if (i) {
2229 xfer->cs_change = false;
2230 xfer->delay_usecs = 0;
2231 }
2232 }
2233
2234 /* set up inserted */
2235 rxfer->inserted = insert;
2236
2237 /* and register it with spi_res/spi_message */
2238 spi_res_add(msg, rxfer);
2239
2240 return rxfer;
2241}
2242EXPORT_SYMBOL_GPL(spi_replace_transfers);
2243
08933418
FE		 2244static int __spi_split_transfer_maxsize(struct spi_master *master,
2245 struct spi_message *msg,
2246 struct spi_transfer **xferp,
2247 size_t maxsize,
2248 gfp_t gfp)
d9f12122
MS		 2249{
2250 struct spi_transfer *xfer = *xferp, *xfers;
2251 struct spi_replaced_transfers *srt;
2252 size_t offset;
2253 size_t count, i;
2254
2255 /* warn once about this fact that we are splitting a transfer */
2256 dev_warn_once(&msg->spi->dev,
2257 "spi_transfer of length %i exceed max length of %i - needed to split transfers\n",
2258 xfer->len, maxsize);
2259
2260 /* calculate how many we have to replace */
2261 count = DIV_ROUND_UP(xfer->len, maxsize);
2262
2263 /* create replacement */
2264 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2265 if (IS_ERR(srt))
2266 return PTR_ERR(srt);
d9f12122
MS		 2267 xfers = srt->inserted_transfers;
2268
2269 /* now handle each of those newly inserted spi_transfers
2270 * note that the replacements spi_transfers all are preset
2271 * to the same values as *xferp, so tx_buf, rx_buf and len
2272 * are all identical (as well as most others)
2273 * so we just have to fix up len and the pointers.
2274 *
2275 * this also includes support for the depreciated
2276 * spi_message.is_dma_mapped interface
2277 */
2278
2279 /* the first transfer just needs the length modified, so we
2280 * run it outside the loop
2281 */
2282 xfers[0].len = min(maxsize, xfer[0].len);
2283
2284 /* all the others need rx_buf/tx_buf also set */
2285 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2286 /* update rx_buf, tx_buf and dma */
2287 if (xfers[i].rx_buf)
2288 xfers[i].rx_buf += offset;
2289 if (xfers[i].rx_dma)
2290 xfers[i].rx_dma += offset;
2291 if (xfers[i].tx_buf)
2292 xfers[i].tx_buf += offset;
2293 if (xfers[i].tx_dma)
2294 xfers[i].tx_dma += offset;
2295
2296 /* update length */
2297 xfers[i].len = min(maxsize, xfers[i].len - offset);
2298 }
2299
2300 /* we set up xferp to the last entry we have inserted,
2301 * so that we skip those already split transfers
2302 */
2303 *xferp = &xfers[count - 1];
2304
2305 /* increment statistics counters */
2306 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2307 transfers_split_maxsize);
2308 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2309 transfers_split_maxsize);
2310
2311 return 0;
2312}
2313
2314/**
2315 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2316 * when an individual transfer exceeds a
2317 * certain size
2318 * @master: the @spi_master for this transfer
2319 * @message: the @spi_message to transform
2320 * @max_size: the maximum when to apply this
2321 *
2322 * Return: status of transformation
2323 */
2324int spi_split_transfers_maxsize(struct spi_master *master,
2325 struct spi_message *msg,
2326 size_t maxsize,
2327 gfp_t gfp)
2328{
2329 struct spi_transfer *xfer;
2330 int ret;
2331
2332 /* iterate over the transfer_list,
2333 * but note that xfer is advanced to the last transfer inserted
2334 * to avoid checking sizes again unnecessarily (also xfer does
2335 * potentiall belong to a different list by the time the
2336 * replacement has happened
2337 */
2338 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2339 if (xfer->len > maxsize) {
2340 ret = __spi_split_transfer_maxsize(
2341 master, msg, &xfer, maxsize, gfp);
2342 if (ret)
2343 return ret;
2344 }
2345 }
2346
2347 return 0;
2348}
2349EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
2350
523baf5a
MS		 2351/*-------------------------------------------------------------------------*/
2352
7d077197
DB		 2353/* Core methods for SPI master protocol drivers. Some of the
2354 * other core methods are currently defined as inline functions.
2355 */
2356
63ab645f
SB		 2357static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2358{
2359 if (master->bits_per_word_mask) {
2360 /* Only 32 bits fit in the mask */
2361 if (bits_per_word > 32)
2362 return -EINVAL;
2363 if (!(master->bits_per_word_mask &
2364 SPI_BPW_MASK(bits_per_word)))
2365 return -EINVAL;
2366 }
2367
2368 return 0;
2369}
2370
7d077197
DB		 2371/**
2372 * spi_setup - setup SPI mode and clock rate
2373 * @spi: the device whose settings are being modified
2374 * Context: can sleep, and no requests are queued to the device
2375 *
2376 * SPI protocol drivers may need to update the transfer mode if the
2377 * device doesn't work with its default. They may likewise need
2378 * to update clock rates or word sizes from initial values. This function
2379 * changes those settings, and must be called from a context that can sleep.
2380 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2381 * effect the next time the device is selected and data is transferred to
2382 * or from it. When this function returns, the spi device is deselected.
2383 *
2384 * Note that this call will fail if the protocol driver specifies an option
2385 * that the underlying controller or its driver does not support. For
2386 * example, not all hardware supports wire transfers using nine bit words,
2387 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2388 *
2389 * Return: zero on success, else a negative error code.
7d077197
DB		 2390 */
2391int spi_setup(struct spi_device *spi)
2392{
83596fbe 2393 unsigned bad_bits, ugly_bits;
5ab8d262 2394 int status;
7d077197 2395
f477b7fb 2396 /* check mode to prevent that DUAL and QUAD set at the same time
2397 */
2398 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2399 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2400 dev_err(&spi->dev,
2401 "setup: can not select dual and quad at the same time\n");
2402 return -EINVAL;
2403 }
2404 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2405 */
2406 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2407 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2408 return -EINVAL;
e7db06b5
DB		 2409 /* help drivers fail *cleanly* when they need options
2410 * that aren't supported with their current master
2411 */
2412 bad_bits = spi->mode & ~spi->master->mode_bits;
83596fbe
GU		 2413 ugly_bits = bad_bits &
2414 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2415 if (ugly_bits) {
2416 dev_warn(&spi->dev,
2417 "setup: ignoring unsupported mode bits %x\n",
2418 ugly_bits);
2419 spi->mode &= ~ugly_bits;
2420 bad_bits &= ~ugly_bits;
2421 }
e7db06b5 2422 if (bad_bits) {
eb288a1f 2423 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2424 bad_bits);
2425 return -EINVAL;
2426 }
2427
7d077197
DB		 2428 if (!spi->bits_per_word)
2429 spi->bits_per_word = 8;
2430
5ab8d262
AS		 2431 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2432 if (status)
2433 return status;
63ab645f 2434
052eb2d4
AL		 2435 if (!spi->max_speed_hz)
2436 spi->max_speed_hz = spi->master->max_speed_hz;
2437
caae070c
LD		 2438 if (spi->master->setup)
2439 status = spi->master->setup(spi);
7d077197 2440
abeedb01
FCJ		 2441 spi_set_cs(spi, false);
2442
5fe5f05e 2443 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2444 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2445 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2446 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2447 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2448 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2449 spi->bits_per_word, spi->max_speed_hz,
2450 status);
2451
2452 return status;
2453}
2454EXPORT_SYMBOL_GPL(spi_setup);
2455
90808738 2456static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2457{
2458 struct spi_master *master = spi->master;
e6811d1d 2459 struct spi_transfer *xfer;
6ea31293 2460 int w_size;
cf32b71e 2461
24a0013a
MB		 2462 if (list_empty(&message->transfers))
2463 return -EINVAL;
24a0013a 2464
cf32b71e
ES		 2465 /* Half-duplex links include original MicroWire, and ones with
2466 * only one data pin like SPI_3WIRE (switches direction) or where
2467 * either MOSI or MISO is missing. They can also be caused by
2468 * software limitations.
2469 */
2470 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2471 || (spi->mode & SPI_3WIRE)) {
cf32b71e
ES		 2472 unsigned flags = master->flags;
2473
2474 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2475 if (xfer->rx_buf && xfer->tx_buf)
2476 return -EINVAL;
2477 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2478 return -EINVAL;
2479 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2480 return -EINVAL;
2481 }
2482 }
2483
e6811d1d 2484 /**
059b8ffe
LD		 2485 * Set transfer bits_per_word and max speed as spi device default if
2486 * it is not set for this transfer.
f477b7fb 2487 * Set transfer tx_nbits and rx_nbits as single transfer default
2488 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2489 */
77e80588 2490 message->frame_length = 0;
e6811d1d 2491 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2492 message->frame_length += xfer->len;
e6811d1d
LD		 2493 if (!xfer->bits_per_word)
2494 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2495
2496 if (!xfer->speed_hz)
059b8ffe 2497 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3
MB		 2498 if (!xfer->speed_hz)
2499 xfer->speed_hz = master->max_speed_hz;
a6f87fad
AL		 2500
2501 if (master->max_speed_hz &&
2502 xfer->speed_hz > master->max_speed_hz)
2503 xfer->speed_hz = master->max_speed_hz;
56ede94a 2504
63ab645f
SB		 2505 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2506 return -EINVAL;
a2fd4f9f 2507
4d94bd21
II		 2508 /*
2509 * SPI transfer length should be multiple of SPI word size
2510 * where SPI word size should be power-of-two multiple
2511 */
2512 if (xfer->bits_per_word <= 8)
2513 w_size = 1;
2514 else if (xfer->bits_per_word <= 16)
2515 w_size = 2;
2516 else
2517 w_size = 4;
2518
4d94bd21 2519 /* No partial transfers accepted */
6ea31293 2520 if (xfer->len % w_size)
4d94bd21
II		 2521 return -EINVAL;
2522
a2fd4f9f
MB		 2523 if (xfer->speed_hz && master->min_speed_hz &&
2524 xfer->speed_hz < master->min_speed_hz)
2525 return -EINVAL;
f477b7fb 2526
2527 if (xfer->tx_buf && !xfer->tx_nbits)
2528 xfer->tx_nbits = SPI_NBITS_SINGLE;
2529 if (xfer->rx_buf && !xfer->rx_nbits)
2530 xfer->rx_nbits = SPI_NBITS_SINGLE;
2531 /* check transfer tx/rx_nbits:
1afd9989
GU		 2532 * 1. check the value matches one of single, dual and quad
2533 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 2534 */
db90a441
SP		 2535 if (xfer->tx_buf) {
2536 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2537 xfer->tx_nbits != SPI_NBITS_DUAL &&
2538 xfer->tx_nbits != SPI_NBITS_QUAD)
2539 return -EINVAL;
2540 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2541 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2542 return -EINVAL;
2543 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2544 !(spi->mode & SPI_TX_QUAD))
2545 return -EINVAL;
db90a441 2546 }
f477b7fb 2547 /* check transfer rx_nbits */
db90a441
SP		 2548 if (xfer->rx_buf) {
2549 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2550 xfer->rx_nbits != SPI_NBITS_DUAL &&
2551 xfer->rx_nbits != SPI_NBITS_QUAD)
2552 return -EINVAL;
2553 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2554 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2555 return -EINVAL;
2556 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2557 !(spi->mode & SPI_RX_QUAD))
2558 return -EINVAL;
db90a441 2559 }
e6811d1d
LD		 2560 }
2561
cf32b71e 2562 message->status = -EINPROGRESS;
90808738
MB		 2563
2564 return 0;
2565}
2566
2567static int __spi_async(struct spi_device *spi, struct spi_message *message)
2568{
2569 struct spi_master *master = spi->master;
2570
2571 message->spi = spi;
2572
eca2ebc7
MS		 2573 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2574 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2575
90808738
MB		 2576 trace_spi_message_submit(message);
2577
cf32b71e
ES		 2578 return master->transfer(spi, message);
2579}
2580
568d0697
DB		 2581/**
2582 * spi_async - asynchronous SPI transfer
2583 * @spi: device with which data will be exchanged
2584 * @message: describes the data transfers, including completion callback
2585 * Context: any (irqs may be blocked, etc)
2586 *
2587 * This call may be used in_irq and other contexts which can't sleep,
2588 * as well as from task contexts which can sleep.
2589 *
2590 * The completion callback is invoked in a context which can't sleep.
2591 * Before that invocation, the value of message->status is undefined.
2592 * When the callback is issued, message->status holds either zero (to
2593 * indicate complete success) or a negative error code. After that
2594 * callback returns, the driver which issued the transfer request may
2595 * deallocate the associated memory; it's no longer in use by any SPI
2596 * core or controller driver code.
2597 *
2598 * Note that although all messages to a spi_device are handled in
2599 * FIFO order, messages may go to different devices in other orders.
2600 * Some device might be higher priority, or have various "hard" access
2601 * time requirements, for example.
2602 *
2603 * On detection of any fault during the transfer, processing of
2604 * the entire message is aborted, and the device is deselected.
2605 * Until returning from the associated message completion callback,
2606 * no other spi_message queued to that device will be processed.
2607 * (This rule applies equally to all the synchronous transfer calls,
2608 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2609 *
2610 * Return: zero on success, else a negative error code.
568d0697
DB		 2611 */
2612int spi_async(struct spi_device *spi, struct spi_message *message)
2613{
2614 struct spi_master *master = spi->master;
cf32b71e
ES		 2615 int ret;
2616 unsigned long flags;
568d0697 2617
90808738
MB		 2618 ret = __spi_validate(spi, message);
2619 if (ret != 0)
2620 return ret;
2621
cf32b71e 2622 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
568d0697 2623
cf32b71e
ES		 2624 if (master->bus_lock_flag)
2625 ret = -EBUSY;
2626 else
2627 ret = __spi_async(spi, message);
568d0697 2628
cf32b71e
ES		 2629 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2630
2631 return ret;
568d0697
DB		 2632}
2633EXPORT_SYMBOL_GPL(spi_async);
2634
cf32b71e
ES		 2635/**
2636 * spi_async_locked - version of spi_async with exclusive bus usage
2637 * @spi: device with which data will be exchanged
2638 * @message: describes the data transfers, including completion callback
2639 * Context: any (irqs may be blocked, etc)
2640 *
2641 * This call may be used in_irq and other contexts which can't sleep,
2642 * as well as from task contexts which can sleep.
2643 *
2644 * The completion callback is invoked in a context which can't sleep.
2645 * Before that invocation, the value of message->status is undefined.
2646 * When the callback is issued, message->status holds either zero (to
2647 * indicate complete success) or a negative error code. After that
2648 * callback returns, the driver which issued the transfer request may
2649 * deallocate the associated memory; it's no longer in use by any SPI
2650 * core or controller driver code.
2651 *
2652 * Note that although all messages to a spi_device are handled in
2653 * FIFO order, messages may go to different devices in other orders.
2654 * Some device might be higher priority, or have various "hard" access
2655 * time requirements, for example.
2656 *
2657 * On detection of any fault during the transfer, processing of
2658 * the entire message is aborted, and the device is deselected.
2659 * Until returning from the associated message completion callback,
2660 * no other spi_message queued to that device will be processed.
2661 * (This rule applies equally to all the synchronous transfer calls,
2662 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2663 *
2664 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2665 */
2666int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2667{
2668 struct spi_master *master = spi->master;
2669 int ret;
2670 unsigned long flags;
2671
90808738
MB		 2672 ret = __spi_validate(spi, message);
2673 if (ret != 0)
2674 return ret;
2675
cf32b71e
ES		 2676 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2677
2678 ret = __spi_async(spi, message);
2679
2680 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2681
2682 return ret;
2683
2684}
2685EXPORT_SYMBOL_GPL(spi_async_locked);
2686
7d077197
DB		 2687
2688/*-------------------------------------------------------------------------*/
2689
2690/* Utility methods for SPI master protocol drivers, layered on
2691 * top of the core. Some other utility methods are defined as
2692 * inline functions.
2693 */
2694
5d870c8e
AM		 2695static void spi_complete(void *arg)
2696{
2697 complete(arg);
2698}
2699
cf32b71e
ES		 2700static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2701 int bus_locked)
2702{
2703 DECLARE_COMPLETION_ONSTACK(done);
2704 int status;
2705 struct spi_master *master = spi->master;
0461a414
MB		 2706 unsigned long flags;
2707
2708 status = __spi_validate(spi, message);
2709 if (status != 0)
2710 return status;
cf32b71e
ES		 2711
2712 message->complete = spi_complete;
2713 message->context = &done;
0461a414 2714 message->spi = spi;
cf32b71e 2715
eca2ebc7
MS		 2716 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2717 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2718
cf32b71e
ES		 2719 if (!bus_locked)
2720 mutex_lock(&master->bus_lock_mutex);
2721
0461a414
MB		 2722 /* If we're not using the legacy transfer method then we will
2723 * try to transfer in the calling context so special case.
2724 * This code would be less tricky if we could remove the
2725 * support for driver implemented message queues.
2726 */
2727 if (master->transfer == spi_queued_transfer) {
2728 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2729
2730 trace_spi_message_submit(message);
2731
2732 status = __spi_queued_transfer(spi, message, false);
2733
2734 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2735 } else {
2736 status = spi_async_locked(spi, message);
2737 }
cf32b71e
ES		 2738
2739 if (!bus_locked)
2740 mutex_unlock(&master->bus_lock_mutex);
2741
2742 if (status == 0) {
0461a414
MB		 2743 /* Push out the messages in the calling context if we
2744 * can.
2745 */
eca2ebc7
MS		 2746 if (master->transfer == spi_queued_transfer) {
2747 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2748 spi_sync_immediate);
2749 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2750 spi_sync_immediate);
fc9e0f71 2751 __spi_pump_messages(master, false);
eca2ebc7 2752 }
0461a414 2753
cf32b71e
ES		 2754 wait_for_completion(&done);
2755 status = message->status;
2756 }
2757 message->context = NULL;
2758 return status;
2759}
2760
8ae12a0d
DB		 2761/**
2762 * spi_sync - blocking/synchronous SPI data transfers
2763 * @spi: device with which data will be exchanged
2764 * @message: describes the data transfers
33e34dc6 2765 * Context: can sleep
8ae12a0d
DB		 2766 *
2767 * This call may only be used from a context that may sleep. The sleep
2768 * is non-interruptible, and has no timeout. Low-overhead controller
2769 * drivers may DMA directly into and out of the message buffers.
2770 *
2771 * Note that the SPI device's chip select is active during the message,
2772 * and then is normally disabled between messages. Drivers for some
2773 * frequently-used devices may want to minimize costs of selecting a chip,
2774 * by leaving it selected in anticipation that the next message will go
2775 * to the same chip. (That may increase power usage.)
2776 *
0c868461
DB		 2777 * Also, the caller is guaranteeing that the memory associated with the
2778 * message will not be freed before this call returns.
2779 *
97d56dc6 2780 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2781 */
2782int spi_sync(struct spi_device *spi, struct spi_message *message)
2783{
cf32b71e 2784 return __spi_sync(spi, message, 0);
8ae12a0d
DB		 2785}
2786EXPORT_SYMBOL_GPL(spi_sync);
2787
cf32b71e
ES		 2788/**
2789 * spi_sync_locked - version of spi_sync with exclusive bus usage
2790 * @spi: device with which data will be exchanged
2791 * @message: describes the data transfers
2792 * Context: can sleep
2793 *
2794 * This call may only be used from a context that may sleep. The sleep
2795 * is non-interruptible, and has no timeout. Low-overhead controller
2796 * drivers may DMA directly into and out of the message buffers.
2797 *
2798 * This call should be used by drivers that require exclusive access to the
25985edc 2799 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 2800 * be released by a spi_bus_unlock call when the exclusive access is over.
2801 *
97d56dc6 2802 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2803 */
2804int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2805{
2806 return __spi_sync(spi, message, 1);
2807}
2808EXPORT_SYMBOL_GPL(spi_sync_locked);
2809
2810/**
2811 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2812 * @master: SPI bus master that should be locked for exclusive bus access
2813 * Context: can sleep
2814 *
2815 * This call may only be used from a context that may sleep. The sleep
2816 * is non-interruptible, and has no timeout.
2817 *
2818 * This call should be used by drivers that require exclusive access to the
2819 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2820 * exclusive access is over. Data transfer must be done by spi_sync_locked
2821 * and spi_async_locked calls when the SPI bus lock is held.
2822 *
97d56dc6 2823 * Return: always zero.
cf32b71e
ES		 2824 */
2825int spi_bus_lock(struct spi_master *master)
2826{
2827 unsigned long flags;
2828
2829 mutex_lock(&master->bus_lock_mutex);
2830
2831 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2832 master->bus_lock_flag = 1;
2833 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2834
2835 /* mutex remains locked until spi_bus_unlock is called */
2836
2837 return 0;
2838}
2839EXPORT_SYMBOL_GPL(spi_bus_lock);
2840
2841/**
2842 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2843 * @master: SPI bus master that was locked for exclusive bus access
2844 * Context: can sleep
2845 *
2846 * This call may only be used from a context that may sleep. The sleep
2847 * is non-interruptible, and has no timeout.
2848 *
2849 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2850 * call.
2851 *
97d56dc6 2852 * Return: always zero.
cf32b71e
ES		 2853 */
2854int spi_bus_unlock(struct spi_master *master)
2855{
2856 master->bus_lock_flag = 0;
2857
2858 mutex_unlock(&master->bus_lock_mutex);
2859
2860 return 0;
2861}
2862EXPORT_SYMBOL_GPL(spi_bus_unlock);
2863
a9948b61 2864/* portable code must never pass more than 32 bytes */
5fe5f05e 2865#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 2866
2867static u8 *buf;
2868
2869/**
2870 * spi_write_then_read - SPI synchronous write followed by read
2871 * @spi: device with which data will be exchanged
2872 * @txbuf: data to be written (need not be dma-safe)
2873 * @n_tx: size of txbuf, in bytes
27570497
JP		 2874 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2875 * @n_rx: size of rxbuf, in bytes
33e34dc6 2876 * Context: can sleep
8ae12a0d
DB		 2877 *
2878 * This performs a half duplex MicroWire style transaction with the
2879 * device, sending txbuf and then reading rxbuf. The return value
2880 * is zero for success, else a negative errno status code.
b885244e 2881 * This call may only be used from a context that may sleep.
8ae12a0d 2882 *
0c868461 2883 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 2884 * portable code should never use this for more than 32 bytes.
2885 * Performance-sensitive or bulk transfer code should instead use
0c868461 2886 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 2887 *
2888 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2889 */
2890int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 2891 const void *txbuf, unsigned n_tx,
2892 void *rxbuf, unsigned n_rx)
8ae12a0d 2893{
068f4070 2894 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 2895
2896 int status;
2897 struct spi_message message;
bdff549e 2898 struct spi_transfer x[2];
8ae12a0d
DB		 2899 u8 *local_buf;
2900
b3a223ee
MB		 2901 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2902 * copying here, (as a pure convenience thing), but we can
2903 * keep heap costs out of the hot path unless someone else is
2904 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 2905 */
b3a223ee 2906 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 2907 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2908 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 2909 if (!local_buf)
2910 return -ENOMEM;
2911 } else {
2912 local_buf = buf;
2913 }
8ae12a0d 2914
8275c642 2915 spi_message_init(&message);
5fe5f05e 2916 memset(x, 0, sizeof(x));
bdff549e
DB		 2917 if (n_tx) {
2918 x[0].len = n_tx;
2919 spi_message_add_tail(&x[0], &message);
2920 }
2921 if (n_rx) {
2922 x[1].len = n_rx;
2923 spi_message_add_tail(&x[1], &message);
2924 }
8275c642 2925
8ae12a0d 2926 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 2927 x[0].tx_buf = local_buf;
2928 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 2929
2930 /* do the i/o */
8ae12a0d 2931 status = spi_sync(spi, &message);
9b938b74 2932 if (status == 0)
bdff549e 2933 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 2934
bdff549e 2935 if (x[0].tx_buf == buf)
068f4070 2936 mutex_unlock(&lock);
8ae12a0d
DB		 2937 else
2938 kfree(local_buf);
2939
2940 return status;
2941}
2942EXPORT_SYMBOL_GPL(spi_write_then_read);
2943
2944/*-------------------------------------------------------------------------*/
2945
ce79d54a
PA		 2946#if IS_ENABLED(CONFIG_OF_DYNAMIC)
2947static int __spi_of_device_match(struct device *dev, void *data)
2948{
2949 return dev->of_node == data;
2950}
2951
2952/* must call put_device() when done with returned spi_device device */
2953static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
2954{
2955 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
2956 __spi_of_device_match);
2957 return dev ? to_spi_device(dev) : NULL;
2958}
2959
2960static int __spi_of_master_match(struct device *dev, const void *data)
2961{
2962 return dev->of_node == data;
2963}
2964
2965/* the spi masters are not using spi_bus, so we find it with another way */
2966static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
2967{
2968 struct device *dev;
2969
2970 dev = class_find_device(&spi_master_class, NULL, node,
2971 __spi_of_master_match);
2972 if (!dev)
2973 return NULL;
2974
2975 /* reference got in class_find_device */
2976 return container_of(dev, struct spi_master, dev);
2977}
2978
2979static int of_spi_notify(struct notifier_block *nb, unsigned long action,
2980 void *arg)
2981{
2982 struct of_reconfig_data *rd = arg;
2983 struct spi_master *master;
2984 struct spi_device *spi;
2985
2986 switch (of_reconfig_get_state_change(action, arg)) {
2987 case OF_RECONFIG_CHANGE_ADD:
2988 master = of_find_spi_master_by_node(rd->dn->parent);
2989 if (master == NULL)
2990 return NOTIFY_OK; /* not for us */
2991
bd6c1644
GU		 2992 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
2993 put_device(&master->dev);
2994 return NOTIFY_OK;
2995 }
2996
ce79d54a
PA		 2997 spi = of_register_spi_device(master, rd->dn);
2998 put_device(&master->dev);
2999
3000 if (IS_ERR(spi)) {
3001 pr_err("%s: failed to create for '%s'\n",
3002 __func__, rd->dn->full_name);
3003 return notifier_from_errno(PTR_ERR(spi));
3004 }
3005 break;
3006
3007 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3008 /* already depopulated? */
3009 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3010 return NOTIFY_OK;
3011
ce79d54a
PA		 3012 /* find our device by node */
3013 spi = of_find_spi_device_by_node(rd->dn);
3014 if (spi == NULL)
3015 return NOTIFY_OK; /* no? not meant for us */
3016
3017 /* unregister takes one ref away */
3018 spi_unregister_device(spi);
3019
3020 /* and put the reference of the find */
3021 put_device(&spi->dev);
3022 break;
3023 }
3024
3025 return NOTIFY_OK;
3026}
3027
3028static struct notifier_block spi_of_notifier = {
3029 .notifier_call = of_spi_notify,
3030};
3031#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3032extern struct notifier_block spi_of_notifier;
3033#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3034
8ae12a0d
DB		 3035static int __init spi_init(void)
3036{
b885244e
DB		 3037 int status;
3038
e94b1766 3039 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3040 if (!buf) {
3041 status = -ENOMEM;
3042 goto err0;
3043 }
3044
3045 status = bus_register(&spi_bus_type);
3046 if (status < 0)
3047 goto err1;
8ae12a0d 3048
b885244e
DB		 3049 status = class_register(&spi_master_class);
3050 if (status < 0)
3051 goto err2;
ce79d54a 3052
5267720e 3053 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a
PA		 3054 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3055
8ae12a0d 3056 return 0;
b885244e
DB		 3057
3058err2:
3059 bus_unregister(&spi_bus_type);
3060err1:
3061 kfree(buf);
3062 buf = NULL;
3063err0:
3064 return status;
8ae12a0d 3065}
b885244e 3066
8ae12a0d
DB		 3067/* board_info is normally registered in arch_initcall(),
3068 * but even essential drivers wait till later
b885244e
DB		 3069 *
3070 * REVISIT only boardinfo really needs static linking. the rest (device and
3071 * driver registration) _could_ be dynamically linked (modular) ... costs
3072 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3073 */
673c0c00 3074postcore_initcall(spi_init);
8ae12a0d 3075
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