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Merge branch 'acpica'
[linux-2.6-block.git] / drivers / spi / spi.c
CommitLineData
8ae12a0d 1/*
ca632f55 2 * SPI init/core code
8ae12a0d
DB		 3 *
4 * Copyright (C) 2005 David Brownell
d57a4282 5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
8ae12a0d
DB		 6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
8ae12a0d
DB		 16 */
17
8ae12a0d
DB		 18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/cache.h>
99adef31
MB		 22#include <linux/dma-mapping.h>
23#include <linux/dmaengine.h>
94040828 24#include <linux/mutex.h>
2b7a32f7 25#include <linux/of_device.h>
d57a4282 26#include <linux/of_irq.h>
86be408b 27#include <linux/clk/clk-conf.h>
5a0e3ad6 28#include <linux/slab.h>
e0626e38 29#include <linux/mod_devicetable.h>
8ae12a0d 30#include <linux/spi/spi.h>
74317984 31#include <linux/of_gpio.h>
3ae22e8c 32#include <linux/pm_runtime.h>
f48c767c 33#include <linux/pm_domain.h>
025ed130 34#include <linux/export.h>
8bd75c77 35#include <linux/sched/rt.h>
ffbbdd21
LW		 36#include <linux/delay.h>
37#include <linux/kthread.h>
64bee4d2
MW		 38#include <linux/ioport.h>
39#include <linux/acpi.h>
8ae12a0d 40
56ec1978
MB		 41#define CREATE_TRACE_POINTS
42#include <trace/events/spi.h>
43
8ae12a0d
DB		 44static void spidev_release(struct device *dev)
45{
0ffa0285 46 struct spi_device *spi = to_spi_device(dev);
8ae12a0d
DB		 47
48 /* spi masters may cleanup for released devices */
49 if (spi->master->cleanup)
50 spi->master->cleanup(spi);
51
0c868461 52 spi_master_put(spi->master);
07a389fe 53 kfree(spi);
8ae12a0d
DB		 54}
55
56static ssize_t
57modalias_show(struct device *dev, struct device_attribute *a, char *buf)
58{
59 const struct spi_device *spi = to_spi_device(dev);
8c4ff6d0
ZR		 60 int len;
61
62 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
63 if (len != -ENODEV)
64 return len;
8ae12a0d 65
d8e328b3 66 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
8ae12a0d 67}
aa7da564 68static DEVICE_ATTR_RO(modalias);
8ae12a0d 69
eca2ebc7
MS		 70#define SPI_STATISTICS_ATTRS(field, file) \
71static ssize_t spi_master_##field##_show(struct device *dev, \
72 struct device_attribute *attr, \
73 char *buf) \
74{ \
75 struct spi_master *master = container_of(dev, \
76 struct spi_master, dev); \
77 return spi_statistics_##field##_show(&master->statistics, buf); \
78} \
79static struct device_attribute dev_attr_spi_master_##field = { \
80 .attr = { .name = file, .mode = S_IRUGO }, \
81 .show = spi_master_##field##_show, \
82}; \
83static ssize_t spi_device_##field##_show(struct device *dev, \
84 struct device_attribute *attr, \
85 char *buf) \
86{ \
d1eba93b 87 struct spi_device *spi = to_spi_device(dev); \
eca2ebc7
MS		 88 return spi_statistics_##field##_show(&spi->statistics, buf); \
89} \
90static struct device_attribute dev_attr_spi_device_##field = { \
91 .attr = { .name = file, .mode = S_IRUGO }, \
92 .show = spi_device_##field##_show, \
93}
94
95#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
96static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
97 char *buf) \
98{ \
99 unsigned long flags; \
100 ssize_t len; \
101 spin_lock_irqsave(&stat->lock, flags); \
102 len = sprintf(buf, format_string, stat->field); \
103 spin_unlock_irqrestore(&stat->lock, flags); \
104 return len; \
105} \
106SPI_STATISTICS_ATTRS(name, file)
107
108#define SPI_STATISTICS_SHOW(field, format_string) \
109 SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
110 field, format_string)
111
112SPI_STATISTICS_SHOW(messages, "%lu");
113SPI_STATISTICS_SHOW(transfers, "%lu");
114SPI_STATISTICS_SHOW(errors, "%lu");
115SPI_STATISTICS_SHOW(timedout, "%lu");
116
117SPI_STATISTICS_SHOW(spi_sync, "%lu");
118SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
119SPI_STATISTICS_SHOW(spi_async, "%lu");
120
121SPI_STATISTICS_SHOW(bytes, "%llu");
122SPI_STATISTICS_SHOW(bytes_rx, "%llu");
123SPI_STATISTICS_SHOW(bytes_tx, "%llu");
124
6b7bc061
MS		 125#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
126 SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
127 "transfer_bytes_histo_" number, \
128 transfer_bytes_histo[index], "%lu")
129SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
130SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
131SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
132SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
133SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
134SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
135SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
136SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
137SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
138SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
139SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
140SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
141SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
142SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
143SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
144SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
145SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
146
d9f12122
MS		 147SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
148
aa7da564
GKH		 149static struct attribute *spi_dev_attrs[] = {
150 &dev_attr_modalias.attr,
151 NULL,
8ae12a0d 152};
eca2ebc7
MS		 153
154static const struct attribute_group spi_dev_group = {
155 .attrs = spi_dev_attrs,
156};
157
158static struct attribute *spi_device_statistics_attrs[] = {
159 &dev_attr_spi_device_messages.attr,
160 &dev_attr_spi_device_transfers.attr,
161 &dev_attr_spi_device_errors.attr,
162 &dev_attr_spi_device_timedout.attr,
163 &dev_attr_spi_device_spi_sync.attr,
164 &dev_attr_spi_device_spi_sync_immediate.attr,
165 &dev_attr_spi_device_spi_async.attr,
166 &dev_attr_spi_device_bytes.attr,
167 &dev_attr_spi_device_bytes_rx.attr,
168 &dev_attr_spi_device_bytes_tx.attr,
6b7bc061
MS		 169 &dev_attr_spi_device_transfer_bytes_histo0.attr,
170 &dev_attr_spi_device_transfer_bytes_histo1.attr,
171 &dev_attr_spi_device_transfer_bytes_histo2.attr,
172 &dev_attr_spi_device_transfer_bytes_histo3.attr,
173 &dev_attr_spi_device_transfer_bytes_histo4.attr,
174 &dev_attr_spi_device_transfer_bytes_histo5.attr,
175 &dev_attr_spi_device_transfer_bytes_histo6.attr,
176 &dev_attr_spi_device_transfer_bytes_histo7.attr,
177 &dev_attr_spi_device_transfer_bytes_histo8.attr,
178 &dev_attr_spi_device_transfer_bytes_histo9.attr,
179 &dev_attr_spi_device_transfer_bytes_histo10.attr,
180 &dev_attr_spi_device_transfer_bytes_histo11.attr,
181 &dev_attr_spi_device_transfer_bytes_histo12.attr,
182 &dev_attr_spi_device_transfer_bytes_histo13.attr,
183 &dev_attr_spi_device_transfer_bytes_histo14.attr,
184 &dev_attr_spi_device_transfer_bytes_histo15.attr,
185 &dev_attr_spi_device_transfer_bytes_histo16.attr,
d9f12122 186 &dev_attr_spi_device_transfers_split_maxsize.attr,
eca2ebc7
MS		 187 NULL,
188};
189
190static const struct attribute_group spi_device_statistics_group = {
191 .name = "statistics",
192 .attrs = spi_device_statistics_attrs,
193};
194
195static const struct attribute_group *spi_dev_groups[] = {
196 &spi_dev_group,
197 &spi_device_statistics_group,
198 NULL,
199};
200
201static struct attribute *spi_master_statistics_attrs[] = {
202 &dev_attr_spi_master_messages.attr,
203 &dev_attr_spi_master_transfers.attr,
204 &dev_attr_spi_master_errors.attr,
205 &dev_attr_spi_master_timedout.attr,
206 &dev_attr_spi_master_spi_sync.attr,
207 &dev_attr_spi_master_spi_sync_immediate.attr,
208 &dev_attr_spi_master_spi_async.attr,
209 &dev_attr_spi_master_bytes.attr,
210 &dev_attr_spi_master_bytes_rx.attr,
211 &dev_attr_spi_master_bytes_tx.attr,
6b7bc061
MS		 212 &dev_attr_spi_master_transfer_bytes_histo0.attr,
213 &dev_attr_spi_master_transfer_bytes_histo1.attr,
214 &dev_attr_spi_master_transfer_bytes_histo2.attr,
215 &dev_attr_spi_master_transfer_bytes_histo3.attr,
216 &dev_attr_spi_master_transfer_bytes_histo4.attr,
217 &dev_attr_spi_master_transfer_bytes_histo5.attr,
218 &dev_attr_spi_master_transfer_bytes_histo6.attr,
219 &dev_attr_spi_master_transfer_bytes_histo7.attr,
220 &dev_attr_spi_master_transfer_bytes_histo8.attr,
221 &dev_attr_spi_master_transfer_bytes_histo9.attr,
222 &dev_attr_spi_master_transfer_bytes_histo10.attr,
223 &dev_attr_spi_master_transfer_bytes_histo11.attr,
224 &dev_attr_spi_master_transfer_bytes_histo12.attr,
225 &dev_attr_spi_master_transfer_bytes_histo13.attr,
226 &dev_attr_spi_master_transfer_bytes_histo14.attr,
227 &dev_attr_spi_master_transfer_bytes_histo15.attr,
228 &dev_attr_spi_master_transfer_bytes_histo16.attr,
d9f12122 229 &dev_attr_spi_master_transfers_split_maxsize.attr,
eca2ebc7
MS		 230 NULL,
231};
232
233static const struct attribute_group spi_master_statistics_group = {
234 .name = "statistics",
235 .attrs = spi_master_statistics_attrs,
236};
237
238static const struct attribute_group *spi_master_groups[] = {
239 &spi_master_statistics_group,
240 NULL,
241};
242
243void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
244 struct spi_transfer *xfer,
245 struct spi_master *master)
246{
247 unsigned long flags;
6b7bc061
MS		 248 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
249
250 if (l2len < 0)
251 l2len = 0;
eca2ebc7
MS		 252
253 spin_lock_irqsave(&stats->lock, flags);
254
255 stats->transfers++;
6b7bc061 256 stats->transfer_bytes_histo[l2len]++;
eca2ebc7
MS		 257
258 stats->bytes += xfer->len;
259 if ((xfer->tx_buf) &&
260 (xfer->tx_buf != master->dummy_tx))
261 stats->bytes_tx += xfer->len;
262 if ((xfer->rx_buf) &&
263 (xfer->rx_buf != master->dummy_rx))
264 stats->bytes_rx += xfer->len;
265
266 spin_unlock_irqrestore(&stats->lock, flags);
267}
268EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
8ae12a0d
DB		 269
270/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
272 */
273
75368bf6
AV		 274static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
275 const struct spi_device *sdev)
276{
277 while (id->name[0]) {
278 if (!strcmp(sdev->modalias, id->name))
279 return id;
280 id++;
281 }
282 return NULL;
283}
284
285const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
286{
287 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
288
289 return spi_match_id(sdrv->id_table, sdev);
290}
291EXPORT_SYMBOL_GPL(spi_get_device_id);
292
8ae12a0d
DB		 293static int spi_match_device(struct device *dev, struct device_driver *drv)
294{
295 const struct spi_device *spi = to_spi_device(dev);
75368bf6
AV		 296 const struct spi_driver *sdrv = to_spi_driver(drv);
297
2b7a32f7
SA		 298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev, drv))
300 return 1;
301
64bee4d2
MW		 302 /* Then try ACPI */
303 if (acpi_driver_match_device(dev, drv))
304 return 1;
305
75368bf6
AV		 306 if (sdrv->id_table)
307 return !!spi_match_id(sdrv->id_table, spi);
8ae12a0d 308
35f74fca 309 return strcmp(spi->modalias, drv->name) == 0;
8ae12a0d
DB		 310}
311
7eff2e7a 312static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
8ae12a0d
DB		 313{
314 const struct spi_device *spi = to_spi_device(dev);
8c4ff6d0
ZR		 315 int rc;
316
317 rc = acpi_device_uevent_modalias(dev, env);
318 if (rc != -ENODEV)
319 return rc;
8ae12a0d 320
e0626e38 321 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
8ae12a0d
DB		 322 return 0;
323}
324
8ae12a0d
DB		 325struct bus_type spi_bus_type = {
326 .name = "spi",
aa7da564 327 .dev_groups = spi_dev_groups,
8ae12a0d
DB		 328 .match = spi_match_device,
329 .uevent = spi_uevent,
8ae12a0d
DB		 330};
331EXPORT_SYMBOL_GPL(spi_bus_type);
332
b885244e
DB		 333
334static int spi_drv_probe(struct device *dev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
44af7927 337 struct spi_device *spi = to_spi_device(dev);
33cf00e5
MW		 338 int ret;
339
86be408b
SN		 340 ret = of_clk_set_defaults(dev->of_node, false);
341 if (ret)
342 return ret;
343
44af7927
JH		 344 if (dev->of_node) {
345 spi->irq = of_irq_get(dev->of_node, 0);
346 if (spi->irq == -EPROBE_DEFER)
347 return -EPROBE_DEFER;
348 if (spi->irq < 0)
349 spi->irq = 0;
350 }
351
676e7c25
UH		 352 ret = dev_pm_domain_attach(dev, true);
353 if (ret != -EPROBE_DEFER) {
44af7927 354 ret = sdrv->probe(spi);
676e7c25
UH		 355 if (ret)
356 dev_pm_domain_detach(dev, true);
357 }
b885244e 358
33cf00e5 359 return ret;
b885244e
DB		 360}
361
362static int spi_drv_remove(struct device *dev)
363{
364 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
33cf00e5
MW		 365 int ret;
366
aec35f4e 367 ret = sdrv->remove(to_spi_device(dev));
676e7c25 368 dev_pm_domain_detach(dev, true);
b885244e 369
33cf00e5 370 return ret;
b885244e
DB		 371}
372
373static void spi_drv_shutdown(struct device *dev)
374{
375 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
376
377 sdrv->shutdown(to_spi_device(dev));
378}
379
33e34dc6 380/**
ca5d2485 381 * __spi_register_driver - register a SPI driver
88c9321d 382 * @owner: owner module of the driver to register
33e34dc6
DB		 383 * @sdrv: the driver to register
384 * Context: can sleep
97d56dc6
JMC		 385 *
386 * Return: zero on success, else a negative error code.
33e34dc6 387 */
ca5d2485 388int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
b885244e 389{
ca5d2485 390 sdrv->driver.owner = owner;
b885244e
DB		 391 sdrv->driver.bus = &spi_bus_type;
392 if (sdrv->probe)
393 sdrv->driver.probe = spi_drv_probe;
394 if (sdrv->remove)
395 sdrv->driver.remove = spi_drv_remove;
396 if (sdrv->shutdown)
397 sdrv->driver.shutdown = spi_drv_shutdown;
398 return driver_register(&sdrv->driver);
399}
ca5d2485 400EXPORT_SYMBOL_GPL(__spi_register_driver);
b885244e 401
8ae12a0d
DB		 402/*-------------------------------------------------------------------------*/
403
404/* SPI devices should normally not be created by SPI device drivers; that
405 * would make them board-specific. Similarly with SPI master drivers.
406 * Device registration normally goes into like arch/.../mach.../board-YYY.c
407 * with other readonly (flashable) information about mainboard devices.
408 */
409
410struct boardinfo {
411 struct list_head list;
2b9603a0 412 struct spi_board_info board_info;
8ae12a0d
DB		 413};
414
415static LIST_HEAD(board_list);
2b9603a0
FT		 416static LIST_HEAD(spi_master_list);
417
418/*
419 * Used to protect add/del opertion for board_info list and
420 * spi_master list, and their matching process
421 */
94040828 422static DEFINE_MUTEX(board_lock);
8ae12a0d 423
dc87c98e
GL		 424/**
425 * spi_alloc_device - Allocate a new SPI device
426 * @master: Controller to which device is connected
427 * Context: can sleep
428 *
429 * Allows a driver to allocate and initialize a spi_device without
430 * registering it immediately. This allows a driver to directly
431 * fill the spi_device with device parameters before calling
432 * spi_add_device() on it.
433 *
434 * Caller is responsible to call spi_add_device() on the returned
435 * spi_device structure to add it to the SPI master. If the caller
436 * needs to discard the spi_device without adding it, then it should
437 * call spi_dev_put() on it.
438 *
97d56dc6 439 * Return: a pointer to the new device, or NULL.
dc87c98e
GL		 440 */
441struct spi_device *spi_alloc_device(struct spi_master *master)
442{
443 struct spi_device *spi;
dc87c98e
GL		 444
445 if (!spi_master_get(master))
446 return NULL;
447
5fe5f05e 448 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
dc87c98e 449 if (!spi) {
dc87c98e
GL		 450 spi_master_put(master);
451 return NULL;
452 }
453
454 spi->master = master;
178db7d3 455 spi->dev.parent = &master->dev;
dc87c98e
GL		 456 spi->dev.bus = &spi_bus_type;
457 spi->dev.release = spidev_release;
446411e1 458 spi->cs_gpio = -ENOENT;
eca2ebc7
MS		 459
460 spin_lock_init(&spi->statistics.lock);
461
dc87c98e
GL		 462 device_initialize(&spi->dev);
463 return spi;
464}
465EXPORT_SYMBOL_GPL(spi_alloc_device);
466
e13ac47b
JN		 467static void spi_dev_set_name(struct spi_device *spi)
468{
469 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
470
471 if (adev) {
472 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
473 return;
474 }
475
476 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
477 spi->chip_select);
478}
479
b6fb8d3a
MW		 480static int spi_dev_check(struct device *dev, void *data)
481{
482 struct spi_device *spi = to_spi_device(dev);
483 struct spi_device *new_spi = data;
484
485 if (spi->master == new_spi->master &&
486 spi->chip_select == new_spi->chip_select)
487 return -EBUSY;
488 return 0;
489}
490
dc87c98e
GL		 491/**
492 * spi_add_device - Add spi_device allocated with spi_alloc_device
493 * @spi: spi_device to register
494 *
495 * Companion function to spi_alloc_device. Devices allocated with
496 * spi_alloc_device can be added onto the spi bus with this function.
497 *
97d56dc6 498 * Return: 0 on success; negative errno on failure
dc87c98e
GL		 499 */
500int spi_add_device(struct spi_device *spi)
501{
e48880e0 502 static DEFINE_MUTEX(spi_add_lock);
74317984
JCPV		 503 struct spi_master *master = spi->master;
504 struct device *dev = master->dev.parent;
dc87c98e
GL		 505 int status;
506
507 /* Chipselects are numbered 0..max; validate. */
74317984 508 if (spi->chip_select >= master->num_chipselect) {
dc87c98e
GL		 509 dev_err(dev, "cs%d >= max %d\n",
510 spi->chip_select,
74317984 511 master->num_chipselect);
dc87c98e
GL		 512 return -EINVAL;
513 }
514
515 /* Set the bus ID string */
e13ac47b 516 spi_dev_set_name(spi);
e48880e0
DB		 517
518 /* We need to make sure there's no other device with this
519 * chipselect **BEFORE** we call setup(), else we'll trash
520 * its configuration. Lock against concurrent add() calls.
521 */
522 mutex_lock(&spi_add_lock);
523
b6fb8d3a
MW		 524 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
525 if (status) {
e48880e0
DB		 526 dev_err(dev, "chipselect %d already in use\n",
527 spi->chip_select);
e48880e0
DB		 528 goto done;
529 }
530
74317984
JCPV		 531 if (master->cs_gpios)
532 spi->cs_gpio = master->cs_gpios[spi->chip_select];
533
e48880e0
DB		 534 /* Drivers may modify this initial i/o setup, but will
535 * normally rely on the device being setup. Devices
536 * using SPI_CS_HIGH can't coexist well otherwise...
537 */
7d077197 538 status = spi_setup(spi);
dc87c98e 539 if (status < 0) {
eb288a1f
LW		 540 dev_err(dev, "can't setup %s, status %d\n",
541 dev_name(&spi->dev), status);
e48880e0 542 goto done;
dc87c98e
GL		 543 }
544
e48880e0 545 /* Device may be bound to an active driver when this returns */
dc87c98e 546 status = device_add(&spi->dev);
e48880e0 547 if (status < 0)
eb288a1f
LW		 548 dev_err(dev, "can't add %s, status %d\n",
549 dev_name(&spi->dev), status);
e48880e0 550 else
35f74fca 551 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
dc87c98e 552
e48880e0
DB		 553done:
554 mutex_unlock(&spi_add_lock);
555 return status;
dc87c98e
GL		 556}
557EXPORT_SYMBOL_GPL(spi_add_device);
8ae12a0d 558
33e34dc6
DB		 559/**
560 * spi_new_device - instantiate one new SPI device
561 * @master: Controller to which device is connected
562 * @chip: Describes the SPI device
563 * Context: can sleep
564 *
565 * On typical mainboards, this is purely internal; and it's not needed
8ae12a0d
DB		 566 * after board init creates the hard-wired devices. Some development
567 * platforms may not be able to use spi_register_board_info though, and
568 * this is exported so that for example a USB or parport based adapter
569 * driver could add devices (which it would learn about out-of-band).
082c8cb4 570 *
97d56dc6 571 * Return: the new device, or NULL.
8ae12a0d 572 */
e9d5a461
AB		 573struct spi_device *spi_new_device(struct spi_master *master,
574 struct spi_board_info *chip)
8ae12a0d
DB		 575{
576 struct spi_device *proxy;
8ae12a0d
DB		 577 int status;
578
082c8cb4
DB		 579 /* NOTE: caller did any chip->bus_num checks necessary.
580 *
581 * Also, unless we change the return value convention to use
582 * error-or-pointer (not NULL-or-pointer), troubleshootability
583 * suggests syslogged diagnostics are best here (ugh).
584 */
585
dc87c98e
GL		 586 proxy = spi_alloc_device(master);
587 if (!proxy)
8ae12a0d
DB		 588 return NULL;
589
102eb975
GL		 590 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
591
8ae12a0d
DB		 592 proxy->chip_select = chip->chip_select;
593 proxy->max_speed_hz = chip->max_speed_hz;
980a01c9 594 proxy->mode = chip->mode;
8ae12a0d 595 proxy->irq = chip->irq;
102eb975 596 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
8ae12a0d
DB		 597 proxy->dev.platform_data = (void *) chip->platform_data;
598 proxy->controller_data = chip->controller_data;
599 proxy->controller_state = NULL;
8ae12a0d 600
dc87c98e 601 status = spi_add_device(proxy);
8ae12a0d 602 if (status < 0) {
dc87c98e
GL		 603 spi_dev_put(proxy);
604 return NULL;
8ae12a0d
DB		 605 }
606
8ae12a0d
DB		 607 return proxy;
608}
609EXPORT_SYMBOL_GPL(spi_new_device);
610
3b1884c2
GU		 611/**
612 * spi_unregister_device - unregister a single SPI device
613 * @spi: spi_device to unregister
614 *
615 * Start making the passed SPI device vanish. Normally this would be handled
616 * by spi_unregister_master().
617 */
618void spi_unregister_device(struct spi_device *spi)
619{
bd6c1644
GU		 620 if (!spi)
621 return;
622
623 if (spi->dev.of_node)
624 of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
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);
df88e91b 709 unsigned int max_seg_size = dma_get_max_seg_size(dev);
65598c13
AG		 710 int desc_len;
711 int sgs;
6ad45a27
MB		 712 struct page *vm_page;
713 void *sg_buf;
714 size_t min;
715 int i, ret;
716
65598c13 717 if (vmalloced_buf) {
df88e91b 718 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
65598c13
AG		 719 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
720 } else {
df88e91b 721 desc_len = min_t(int, max_seg_size, master->max_dma_len);
65598c13
AG		 722 sgs = DIV_ROUND_UP(len, desc_len);
723 }
724
6ad45a27
MB		 725 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
726 if (ret != 0)
727 return ret;
728
729 for (i = 0; i < sgs; i++) {
6ad45a27
MB		 730
731 if (vmalloced_buf) {
65598c13
AG		 732 min = min_t(size_t,
733 len, desc_len - offset_in_page(buf));
6ad45a27
MB		 734 vm_page = vmalloc_to_page(buf);
735 if (!vm_page) {
736 sg_free_table(sgt);
737 return -ENOMEM;
738 }
c1aefbdd
CK		 739 sg_set_page(&sgt->sgl[i], vm_page,
740 min, offset_in_page(buf));
6ad45a27 741 } else {
65598c13 742 min = min_t(size_t, len, desc_len);
6ad45a27 743 sg_buf = buf;
c1aefbdd 744 sg_set_buf(&sgt->sgl[i], sg_buf, min);
6ad45a27
MB		 745 }
746
6ad45a27
MB		 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
49023d2e 1056 * @bus_locked: true if the bus mutex is held when calling this function
ffbbdd21
LW		 1057 *
1058 * This function checks if there is any spi message in the queue that
1059 * needs processing and if so call out to the driver to initialize hardware
1060 * and transfer each message.
1061 *
0461a414
MB		 1062 * Note that it is called both from the kthread itself and also from
1063 * inside spi_sync(); the queue extraction handling at the top of the
1064 * function should deal with this safely.
ffbbdd21 1065 */
49023d2e
JH		 1066static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
1067 bool bus_locked)
ffbbdd21 1068{
ffbbdd21
LW		 1069 unsigned long flags;
1070 bool was_busy = false;
1071 int ret;
1072
983aee5d 1073 /* Lock queue */
ffbbdd21 1074 spin_lock_irqsave(&master->queue_lock, flags);
983aee5d
MB		 1075
1076 /* Make sure we are not already running a message */
1077 if (master->cur_msg) {
1078 spin_unlock_irqrestore(&master->queue_lock, flags);
1079 return;
1080 }
1081
0461a414
MB		 1082 /* If another context is idling the device then defer */
1083 if (master->idling) {
1084 queue_kthread_work(&master->kworker, &master->pump_messages);
1085 spin_unlock_irqrestore(&master->queue_lock, flags);
1086 return;
1087 }
1088
983aee5d 1089 /* Check if the queue is idle */
ffbbdd21 1090 if (list_empty(&master->queue) || !master->running) {
b0b36b86
BF		 1091 if (!master->busy) {
1092 spin_unlock_irqrestore(&master->queue_lock, flags);
1093 return;
ffbbdd21 1094 }
fc9e0f71
MB		 1095
1096 /* Only do teardown in the thread */
1097 if (!in_kthread) {
1098 queue_kthread_work(&master->kworker,
1099 &master->pump_messages);
1100 spin_unlock_irqrestore(&master->queue_lock, flags);
1101 return;
1102 }
1103
ffbbdd21 1104 master->busy = false;
0461a414 1105 master->idling = true;
ffbbdd21 1106 spin_unlock_irqrestore(&master->queue_lock, flags);
0461a414 1107
3a2eba9b
MB		 1108 kfree(master->dummy_rx);
1109 master->dummy_rx = NULL;
1110 kfree(master->dummy_tx);
1111 master->dummy_tx = NULL;
b0b36b86
BF		 1112 if (master->unprepare_transfer_hardware &&
1113 master->unprepare_transfer_hardware(master))
1114 dev_err(&master->dev,
1115 "failed to unprepare transfer hardware\n");
49834de2
MB		 1116 if (master->auto_runtime_pm) {
1117 pm_runtime_mark_last_busy(master->dev.parent);
1118 pm_runtime_put_autosuspend(master->dev.parent);
1119 }
56ec1978 1120 trace_spi_master_idle(master);
ffbbdd21 1121
0461a414
MB		 1122 spin_lock_irqsave(&master->queue_lock, flags);
1123 master->idling = false;
ffbbdd21
LW		 1124 spin_unlock_irqrestore(&master->queue_lock, flags);
1125 return;
1126 }
ffbbdd21 1127
ffbbdd21
LW		 1128 /* Extract head of queue */
1129 master->cur_msg =
a89e2d27 1130 list_first_entry(&master->queue, struct spi_message, queue);
ffbbdd21
LW		 1131
1132 list_del_init(&master->cur_msg->queue);
1133 if (master->busy)
1134 was_busy = true;
1135 else
1136 master->busy = true;
1137 spin_unlock_irqrestore(&master->queue_lock, flags);
1138
49834de2
MB		 1139 if (!was_busy && master->auto_runtime_pm) {
1140 ret = pm_runtime_get_sync(master->dev.parent);
1141 if (ret < 0) {
1142 dev_err(&master->dev, "Failed to power device: %d\n",
1143 ret);
1144 return;
1145 }
1146 }
1147
56ec1978
MB		 1148 if (!was_busy)
1149 trace_spi_master_busy(master);
1150
7dfd2bd7 1151 if (!was_busy && master->prepare_transfer_hardware) {
ffbbdd21
LW		 1152 ret = master->prepare_transfer_hardware(master);
1153 if (ret) {
1154 dev_err(&master->dev,
1155 "failed to prepare transfer hardware\n");
49834de2
MB		 1156
1157 if (master->auto_runtime_pm)
1158 pm_runtime_put(master->dev.parent);
ffbbdd21
LW		 1159 return;
1160 }
1161 }
1162
49023d2e
JH		 1163 if (!bus_locked)
1164 mutex_lock(&master->bus_lock_mutex);
1165
56ec1978
MB		 1166 trace_spi_message_start(master->cur_msg);
1167
2841a5fc
MB		 1168 if (master->prepare_message) {
1169 ret = master->prepare_message(master, master->cur_msg);
1170 if (ret) {
1171 dev_err(&master->dev,
1172 "failed to prepare message: %d\n", ret);
1173 master->cur_msg->status = ret;
1174 spi_finalize_current_message(master);
49023d2e 1175 goto out;
2841a5fc
MB		 1176 }
1177 master->cur_msg_prepared = true;
1178 }
1179
99adef31
MB		 1180 ret = spi_map_msg(master, master->cur_msg);
1181 if (ret) {
1182 master->cur_msg->status = ret;
1183 spi_finalize_current_message(master);
49023d2e 1184 goto out;
99adef31
MB		 1185 }
1186
ffbbdd21
LW		 1187 ret = master->transfer_one_message(master, master->cur_msg);
1188 if (ret) {
1189 dev_err(&master->dev,
1f802f82 1190 "failed to transfer one message from queue\n");
49023d2e 1191 goto out;
ffbbdd21 1192 }
49023d2e
JH		 1193
1194out:
1195 if (!bus_locked)
1196 mutex_unlock(&master->bus_lock_mutex);
62826970
MB		 1197
1198 /* Prod the scheduler in case transfer_one() was busy waiting */
49023d2e
JH		 1199 if (!ret)
1200 cond_resched();
ffbbdd21
LW		 1201}
1202
fc9e0f71
MB		 1203/**
1204 * spi_pump_messages - kthread work function which processes spi message queue
1205 * @work: pointer to kthread work struct contained in the master struct
1206 */
1207static void spi_pump_messages(struct kthread_work *work)
1208{
1209 struct spi_master *master =
1210 container_of(work, struct spi_master, pump_messages);
1211
24c8cd1b 1212 __spi_pump_messages(master, true, master->bus_lock_flag);
fc9e0f71
MB		 1213}
1214
ffbbdd21
LW		 1215static int spi_init_queue(struct spi_master *master)
1216{
1217 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1218
ffbbdd21
LW		 1219 master->running = false;
1220 master->busy = false;
1221
1222 init_kthread_worker(&master->kworker);
1223 master->kworker_task = kthread_run(kthread_worker_fn,
f170168b 1224 &master->kworker, "%s",
ffbbdd21
LW		 1225 dev_name(&master->dev));
1226 if (IS_ERR(master->kworker_task)) {
1227 dev_err(&master->dev, "failed to create message pump task\n");
98a8f5a0 1228 return PTR_ERR(master->kworker_task);
ffbbdd21
LW		 1229 }
1230 init_kthread_work(&master->pump_messages, spi_pump_messages);
1231
1232 /*
1233 * Master config will indicate if this controller should run the
1234 * message pump with high (realtime) priority to reduce the transfer
1235 * latency on the bus by minimising the delay between a transfer
1236 * request and the scheduling of the message pump thread. Without this
1237 * setting the message pump thread will remain at default priority.
1238 */
1239 if (master->rt) {
1240 dev_info(&master->dev,
1241 "will run message pump with realtime priority\n");
1242 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1243 }
1244
1245 return 0;
1246}
1247
1248/**
1249 * spi_get_next_queued_message() - called by driver to check for queued
1250 * messages
1251 * @master: the master to check for queued messages
1252 *
1253 * If there are more messages in the queue, the next message is returned from
1254 * this call.
97d56dc6
JMC		 1255 *
1256 * Return: the next message in the queue, else NULL if the queue is empty.
ffbbdd21
LW		 1257 */
1258struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1259{
1260 struct spi_message *next;
1261 unsigned long flags;
1262
1263 /* get a pointer to the next message, if any */
1264 spin_lock_irqsave(&master->queue_lock, flags);
1cfd97f9
AL		 1265 next = list_first_entry_or_null(&master->queue, struct spi_message,
1266 queue);
ffbbdd21
LW		 1267 spin_unlock_irqrestore(&master->queue_lock, flags);
1268
1269 return next;
1270}
1271EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1272
1273/**
1274 * spi_finalize_current_message() - the current message is complete
1275 * @master: the master to return the message to
1276 *
1277 * Called by the driver to notify the core that the message in the front of the
1278 * queue is complete and can be removed from the queue.
1279 */
1280void spi_finalize_current_message(struct spi_master *master)
1281{
1282 struct spi_message *mesg;
1283 unsigned long flags;
2841a5fc 1284 int ret;
ffbbdd21
LW		 1285
1286 spin_lock_irqsave(&master->queue_lock, flags);
1287 mesg = master->cur_msg;
ffbbdd21
LW		 1288 spin_unlock_irqrestore(&master->queue_lock, flags);
1289
99adef31
MB		 1290 spi_unmap_msg(master, mesg);
1291
2841a5fc
MB		 1292 if (master->cur_msg_prepared && master->unprepare_message) {
1293 ret = master->unprepare_message(master, mesg);
1294 if (ret) {
1295 dev_err(&master->dev,
1296 "failed to unprepare message: %d\n", ret);
1297 }
1298 }
391949b6 1299
8e76ef88
MS		 1300 spin_lock_irqsave(&master->queue_lock, flags);
1301 master->cur_msg = NULL;
2841a5fc 1302 master->cur_msg_prepared = false;
8e76ef88
MS		 1303 queue_kthread_work(&master->kworker, &master->pump_messages);
1304 spin_unlock_irqrestore(&master->queue_lock, flags);
1305
1306 trace_spi_message_done(mesg);
2841a5fc 1307
ffbbdd21
LW		 1308 mesg->state = NULL;
1309 if (mesg->complete)
1310 mesg->complete(mesg->context);
1311}
1312EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1313
1314static int spi_start_queue(struct spi_master *master)
1315{
1316 unsigned long flags;
1317
1318 spin_lock_irqsave(&master->queue_lock, flags);
1319
1320 if (master->running || master->busy) {
1321 spin_unlock_irqrestore(&master->queue_lock, flags);
1322 return -EBUSY;
1323 }
1324
1325 master->running = true;
1326 master->cur_msg = NULL;
1327 spin_unlock_irqrestore(&master->queue_lock, flags);
1328
1329 queue_kthread_work(&master->kworker, &master->pump_messages);
1330
1331 return 0;
1332}
1333
1334static int spi_stop_queue(struct spi_master *master)
1335{
1336 unsigned long flags;
1337 unsigned limit = 500;
1338 int ret = 0;
1339
1340 spin_lock_irqsave(&master->queue_lock, flags);
1341
1342 /*
1343 * This is a bit lame, but is optimized for the common execution path.
1344 * A wait_queue on the master->busy could be used, but then the common
1345 * execution path (pump_messages) would be required to call wake_up or
1346 * friends on every SPI message. Do this instead.
1347 */
1348 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1349 spin_unlock_irqrestore(&master->queue_lock, flags);
f97b26b0 1350 usleep_range(10000, 11000);
ffbbdd21
LW		 1351 spin_lock_irqsave(&master->queue_lock, flags);
1352 }
1353
1354 if (!list_empty(&master->queue) || master->busy)
1355 ret = -EBUSY;
1356 else
1357 master->running = false;
1358
1359 spin_unlock_irqrestore(&master->queue_lock, flags);
1360
1361 if (ret) {
1362 dev_warn(&master->dev,
1363 "could not stop message queue\n");
1364 return ret;
1365 }
1366 return ret;
1367}
1368
1369static int spi_destroy_queue(struct spi_master *master)
1370{
1371 int ret;
1372
1373 ret = spi_stop_queue(master);
1374
1375 /*
1376 * flush_kthread_worker will block until all work is done.
1377 * If the reason that stop_queue timed out is that the work will never
1378 * finish, then it does no good to call flush/stop thread, so
1379 * return anyway.
1380 */
1381 if (ret) {
1382 dev_err(&master->dev, "problem destroying queue\n");
1383 return ret;
1384 }
1385
1386 flush_kthread_worker(&master->kworker);
1387 kthread_stop(master->kworker_task);
1388
1389 return 0;
1390}
1391
0461a414
MB		 1392static int __spi_queued_transfer(struct spi_device *spi,
1393 struct spi_message *msg,
1394 bool need_pump)
ffbbdd21
LW		 1395{
1396 struct spi_master *master = spi->master;
1397 unsigned long flags;
1398
1399 spin_lock_irqsave(&master->queue_lock, flags);
1400
1401 if (!master->running) {
1402 spin_unlock_irqrestore(&master->queue_lock, flags);
1403 return -ESHUTDOWN;
1404 }
1405 msg->actual_length = 0;
1406 msg->status = -EINPROGRESS;
1407
1408 list_add_tail(&msg->queue, &master->queue);
0461a414 1409 if (!master->busy && need_pump)
ffbbdd21
LW		 1410 queue_kthread_work(&master->kworker, &master->pump_messages);
1411
1412 spin_unlock_irqrestore(&master->queue_lock, flags);
1413 return 0;
1414}
1415
0461a414
MB		 1416/**
1417 * spi_queued_transfer - transfer function for queued transfers
1418 * @spi: spi device which is requesting transfer
1419 * @msg: spi message which is to handled is queued to driver queue
97d56dc6
JMC		 1420 *
1421 * Return: zero on success, else a negative error code.
0461a414
MB		 1422 */
1423static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1424{
1425 return __spi_queued_transfer(spi, msg, true);
1426}
1427
ffbbdd21
LW		 1428static int spi_master_initialize_queue(struct spi_master *master)
1429{
1430 int ret;
1431
ffbbdd21 1432 master->transfer = spi_queued_transfer;
b158935f
MB		 1433 if (!master->transfer_one_message)
1434 master->transfer_one_message = spi_transfer_one_message;
ffbbdd21
LW		 1435
1436 /* Initialize and start queue */
1437 ret = spi_init_queue(master);
1438 if (ret) {
1439 dev_err(&master->dev, "problem initializing queue\n");
1440 goto err_init_queue;
1441 }
c3676d5c 1442 master->queued = true;
ffbbdd21
LW		 1443 ret = spi_start_queue(master);
1444 if (ret) {
1445 dev_err(&master->dev, "problem starting queue\n");
1446 goto err_start_queue;
1447 }
1448
1449 return 0;
1450
1451err_start_queue:
ffbbdd21 1452 spi_destroy_queue(master);
c3676d5c 1453err_init_queue:
ffbbdd21
LW		 1454 return ret;
1455}
1456
1457/*-------------------------------------------------------------------------*/
1458
7cb94361 1459#if defined(CONFIG_OF)
aff5e3f8
PA		 1460static struct spi_device *
1461of_register_spi_device(struct spi_master *master, struct device_node *nc)
1462{
1463 struct spi_device *spi;
1464 int rc;
1465 u32 value;
1466
1467 /* Alloc an spi_device */
1468 spi = spi_alloc_device(master);
1469 if (!spi) {
1470 dev_err(&master->dev, "spi_device alloc error for %s\n",
1471 nc->full_name);
1472 rc = -ENOMEM;
1473 goto err_out;
1474 }
1475
1476 /* Select device driver */
1477 rc = of_modalias_node(nc, spi->modalias,
1478 sizeof(spi->modalias));
1479 if (rc < 0) {
1480 dev_err(&master->dev, "cannot find modalias for %s\n",
1481 nc->full_name);
1482 goto err_out;
1483 }
1484
1485 /* Device address */
1486 rc = of_property_read_u32(nc, "reg", &value);
1487 if (rc) {
1488 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1489 nc->full_name, rc);
1490 goto err_out;
1491 }
1492 spi->chip_select = value;
1493
1494 /* Mode (clock phase/polarity/etc.) */
1495 if (of_find_property(nc, "spi-cpha", NULL))
1496 spi->mode |= SPI_CPHA;
1497 if (of_find_property(nc, "spi-cpol", NULL))
1498 spi->mode |= SPI_CPOL;
1499 if (of_find_property(nc, "spi-cs-high", NULL))
1500 spi->mode |= SPI_CS_HIGH;
1501 if (of_find_property(nc, "spi-3wire", NULL))
1502 spi->mode |= SPI_3WIRE;
1503 if (of_find_property(nc, "spi-lsb-first", NULL))
1504 spi->mode |= SPI_LSB_FIRST;
1505
1506 /* Device DUAL/QUAD mode */
1507 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1508 switch (value) {
1509 case 1:
1510 break;
1511 case 2:
1512 spi->mode |= SPI_TX_DUAL;
1513 break;
1514 case 4:
1515 spi->mode |= SPI_TX_QUAD;
1516 break;
1517 default:
1518 dev_warn(&master->dev,
1519 "spi-tx-bus-width %d not supported\n",
1520 value);
1521 break;
1522 }
1523 }
1524
1525 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1526 switch (value) {
1527 case 1:
1528 break;
1529 case 2:
1530 spi->mode |= SPI_RX_DUAL;
1531 break;
1532 case 4:
1533 spi->mode |= SPI_RX_QUAD;
1534 break;
1535 default:
1536 dev_warn(&master->dev,
1537 "spi-rx-bus-width %d not supported\n",
1538 value);
1539 break;
1540 }
1541 }
1542
1543 /* Device speed */
1544 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1545 if (rc) {
1546 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1547 nc->full_name, rc);
1548 goto err_out;
1549 }
1550 spi->max_speed_hz = value;
1551
aff5e3f8
PA		 1552 /* Store a pointer to the node in the device structure */
1553 of_node_get(nc);
1554 spi->dev.of_node = nc;
1555
1556 /* Register the new device */
aff5e3f8
PA		 1557 rc = spi_add_device(spi);
1558 if (rc) {
1559 dev_err(&master->dev, "spi_device register error %s\n",
1560 nc->full_name);
1561 goto err_out;
1562 }
1563
1564 return spi;
1565
1566err_out:
1567 spi_dev_put(spi);
1568 return ERR_PTR(rc);
1569}
1570
d57a4282
GL		 1571/**
1572 * of_register_spi_devices() - Register child devices onto the SPI bus
1573 * @master: Pointer to spi_master device
1574 *
1575 * Registers an spi_device for each child node of master node which has a 'reg'
1576 * property.
1577 */
1578static void of_register_spi_devices(struct spi_master *master)
1579{
1580 struct spi_device *spi;
1581 struct device_node *nc;
d57a4282
GL		 1582
1583 if (!master->dev.of_node)
1584 return;
1585
f3b6159e 1586 for_each_available_child_of_node(master->dev.of_node, nc) {
bd6c1644
GU		 1587 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1588 continue;
aff5e3f8
PA		 1589 spi = of_register_spi_device(master, nc);
1590 if (IS_ERR(spi))
1591 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
d57a4282 1592 nc->full_name);
d57a4282
GL		 1593 }
1594}
1595#else
1596static void of_register_spi_devices(struct spi_master *master) { }
1597#endif
1598
64bee4d2
MW		 1599#ifdef CONFIG_ACPI
1600static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1601{
1602 struct spi_device *spi = data;
a0a90718 1603 struct spi_master *master = spi->master;
64bee4d2
MW		 1604
1605 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1606 struct acpi_resource_spi_serialbus *sb;
1607
1608 sb = &ares->data.spi_serial_bus;
1609 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
a0a90718
MW		 1610 /*
1611 * ACPI DeviceSelection numbering is handled by the
1612 * host controller driver in Windows and can vary
1613 * from driver to driver. In Linux we always expect
1614 * 0 .. max - 1 so we need to ask the driver to
1615 * translate between the two schemes.
1616 */
1617 if (master->fw_translate_cs) {
1618 int cs = master->fw_translate_cs(master,
1619 sb->device_selection);
1620 if (cs < 0)
1621 return cs;
1622 spi->chip_select = cs;
1623 } else {
1624 spi->chip_select = sb->device_selection;
1625 }
1626
64bee4d2
MW		 1627 spi->max_speed_hz = sb->connection_speed;
1628
1629 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1630 spi->mode |= SPI_CPHA;
1631 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1632 spi->mode |= SPI_CPOL;
1633 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1634 spi->mode |= SPI_CS_HIGH;
1635 }
1636 } else if (spi->irq < 0) {
1637 struct resource r;
1638
1639 if (acpi_dev_resource_interrupt(ares, 0, &r))
1640 spi->irq = r.start;
1641 }
1642
1643 /* Always tell the ACPI core to skip this resource */
1644 return 1;
1645}
1646
1647static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1648 void *data, void **return_value)
1649{
1650 struct spi_master *master = data;
1651 struct list_head resource_list;
1652 struct acpi_device *adev;
1653 struct spi_device *spi;
1654 int ret;
1655
1656 if (acpi_bus_get_device(handle, &adev))
1657 return AE_OK;
1658 if (acpi_bus_get_status(adev) || !adev->status.present)
1659 return AE_OK;
1660
1661 spi = spi_alloc_device(master);
1662 if (!spi) {
1663 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1664 dev_name(&adev->dev));
1665 return AE_NO_MEMORY;
1666 }
1667
7b199811 1668 ACPI_COMPANION_SET(&spi->dev, adev);
64bee4d2
MW		 1669 spi->irq = -1;
1670
1671 INIT_LIST_HEAD(&resource_list);
1672 ret = acpi_dev_get_resources(adev, &resource_list,
1673 acpi_spi_add_resource, spi);
1674 acpi_dev_free_resource_list(&resource_list);
1675
1676 if (ret < 0 || !spi->max_speed_hz) {
1677 spi_dev_put(spi);
1678 return AE_OK;
1679 }
1680
33ada67d
CR		 1681 if (spi->irq < 0)
1682 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1683
33cf00e5 1684 adev->power.flags.ignore_parent = true;
cf9eb39c 1685 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
64bee4d2 1686 if (spi_add_device(spi)) {
33cf00e5 1687 adev->power.flags.ignore_parent = false;
64bee4d2
MW		 1688 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1689 dev_name(&adev->dev));
1690 spi_dev_put(spi);
1691 }
1692
1693 return AE_OK;
1694}
1695
1696static void acpi_register_spi_devices(struct spi_master *master)
1697{
1698 acpi_status status;
1699 acpi_handle handle;
1700
29896178 1701 handle = ACPI_HANDLE(master->dev.parent);
64bee4d2
MW		 1702 if (!handle)
1703 return;
1704
1705 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1706 acpi_spi_add_device, NULL,
1707 master, NULL);
1708 if (ACPI_FAILURE(status))
1709 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1710}
1711#else
1712static inline void acpi_register_spi_devices(struct spi_master *master) {}
1713#endif /* CONFIG_ACPI */
1714
49dce689 1715static void spi_master_release(struct device *dev)
8ae12a0d
DB		 1716{
1717 struct spi_master *master;
1718
49dce689 1719 master = container_of(dev, struct spi_master, dev);
8ae12a0d
DB		 1720 kfree(master);
1721}
1722
1723static struct class spi_master_class = {
1724 .name = "spi_master",
1725 .owner = THIS_MODULE,
49dce689 1726 .dev_release = spi_master_release,
eca2ebc7 1727 .dev_groups = spi_master_groups,
8ae12a0d
DB		 1728};
1729
1730
1731/**
1732 * spi_alloc_master - allocate SPI master controller
1733 * @dev: the controller, possibly using the platform_bus
33e34dc6 1734 * @size: how much zeroed driver-private data to allocate; the pointer to this
49dce689 1735 * memory is in the driver_data field of the returned device,
0c868461 1736 * accessible with spi_master_get_devdata().
33e34dc6 1737 * Context: can sleep
8ae12a0d
DB		 1738 *
1739 * This call is used only by SPI master controller drivers, which are the
1740 * only ones directly touching chip registers. It's how they allocate
ba1a0513 1741 * an spi_master structure, prior to calling spi_register_master().
8ae12a0d 1742 *
97d56dc6 1743 * This must be called from context that can sleep.
8ae12a0d
DB		 1744 *
1745 * The caller is responsible for assigning the bus number and initializing
ba1a0513 1746 * the master's methods before calling spi_register_master(); and (after errors
a394d635 1747 * adding the device) calling spi_master_put() to prevent a memory leak.
97d56dc6
JMC		 1748 *
1749 * Return: the SPI master structure on success, else NULL.
8ae12a0d 1750 */
e9d5a461 1751struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
8ae12a0d
DB		 1752{
1753 struct spi_master *master;
1754
0c868461
DB		 1755 if (!dev)
1756 return NULL;
1757
5fe5f05e 1758 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
8ae12a0d
DB		 1759 if (!master)
1760 return NULL;
1761
49dce689 1762 device_initialize(&master->dev);
1e8a52e1
GL		 1763 master->bus_num = -1;
1764 master->num_chipselect = 1;
49dce689 1765 master->dev.class = &spi_master_class;
157f38f9 1766 master->dev.parent = dev;
0c868461 1767 spi_master_set_devdata(master, &master[1]);
8ae12a0d
DB		 1768
1769 return master;
1770}
1771EXPORT_SYMBOL_GPL(spi_alloc_master);
1772
74317984
JCPV		 1773#ifdef CONFIG_OF
1774static int of_spi_register_master(struct spi_master *master)
1775{
e80beb27 1776 int nb, i, *cs;
74317984
JCPV		 1777 struct device_node *np = master->dev.of_node;
1778
1779 if (!np)
1780 return 0;
1781
1782 nb = of_gpio_named_count(np, "cs-gpios");
5fe5f05e 1783 master->num_chipselect = max_t(int, nb, master->num_chipselect);
74317984 1784
8ec5d84e
AL		 1785 /* Return error only for an incorrectly formed cs-gpios property */
1786 if (nb == 0 || nb == -ENOENT)
74317984 1787 return 0;
8ec5d84e
AL		 1788 else if (nb < 0)
1789 return nb;
74317984
JCPV		 1790
1791 cs = devm_kzalloc(&master->dev,
1792 sizeof(int) * master->num_chipselect,
1793 GFP_KERNEL);
1794 master->cs_gpios = cs;
1795
1796 if (!master->cs_gpios)
1797 return -ENOMEM;
1798
0da83bb1 1799 for (i = 0; i < master->num_chipselect; i++)
446411e1 1800 cs[i] = -ENOENT;
74317984
JCPV		 1801
1802 for (i = 0; i < nb; i++)
1803 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1804
1805 return 0;
1806}
1807#else
1808static int of_spi_register_master(struct spi_master *master)
1809{
1810 return 0;
1811}
1812#endif
1813
8ae12a0d
DB		 1814/**
1815 * spi_register_master - register SPI master controller
1816 * @master: initialized master, originally from spi_alloc_master()
33e34dc6 1817 * Context: can sleep
8ae12a0d
DB		 1818 *
1819 * SPI master controllers connect to their drivers using some non-SPI bus,
1820 * such as the platform bus. The final stage of probe() in that code
1821 * includes calling spi_register_master() to hook up to this SPI bus glue.
1822 *
1823 * SPI controllers use board specific (often SOC specific) bus numbers,
1824 * and board-specific addressing for SPI devices combines those numbers
1825 * with chip select numbers. Since SPI does not directly support dynamic
1826 * device identification, boards need configuration tables telling which
1827 * chip is at which address.
1828 *
1829 * This must be called from context that can sleep. It returns zero on
1830 * success, else a negative error code (dropping the master's refcount).
0c868461
DB		 1831 * After a successful return, the caller is responsible for calling
1832 * spi_unregister_master().
97d56dc6
JMC		 1833 *
1834 * Return: zero on success, else a negative error code.
8ae12a0d 1835 */
e9d5a461 1836int spi_register_master(struct spi_master *master)
8ae12a0d 1837{
e44a45ae 1838 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
49dce689 1839 struct device *dev = master->dev.parent;
2b9603a0 1840 struct boardinfo *bi;
8ae12a0d
DB		 1841 int status = -ENODEV;
1842 int dynamic = 0;
1843
0c868461
DB		 1844 if (!dev)
1845 return -ENODEV;
1846
74317984
JCPV		 1847 status = of_spi_register_master(master);
1848 if (status)
1849 return status;
1850
082c8cb4
DB		 1851 /* even if it's just one always-selected device, there must
1852 * be at least one chipselect
1853 */
1854 if (master->num_chipselect == 0)
1855 return -EINVAL;
1856
bb29785e
GL		 1857 if ((master->bus_num < 0) && master->dev.of_node)
1858 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1859
8ae12a0d 1860 /* convention: dynamically assigned bus IDs count down from the max */
a020ed75 1861 if (master->bus_num < 0) {
082c8cb4
DB		 1862 /* FIXME switch to an IDR based scheme, something like
1863 * I2C now uses, so we can't run out of "dynamic" IDs
1864 */
8ae12a0d 1865 master->bus_num = atomic_dec_return(&dyn_bus_id);
b885244e 1866 dynamic = 1;
8ae12a0d
DB		 1867 }
1868
5424d43e
MB		 1869 INIT_LIST_HEAD(&master->queue);
1870 spin_lock_init(&master->queue_lock);
cf32b71e
ES		 1871 spin_lock_init(&master->bus_lock_spinlock);
1872 mutex_init(&master->bus_lock_mutex);
1873 master->bus_lock_flag = 0;
b158935f 1874 init_completion(&master->xfer_completion);
6ad45a27
MB		 1875 if (!master->max_dma_len)
1876 master->max_dma_len = INT_MAX;
cf32b71e 1877
8ae12a0d
DB		 1878 /* register the device, then userspace will see it.
1879 * registration fails if the bus ID is in use.
1880 */
35f74fca 1881 dev_set_name(&master->dev, "spi%u", master->bus_num);
49dce689 1882 status = device_add(&master->dev);
b885244e 1883 if (status < 0)
8ae12a0d 1884 goto done;
35f74fca 1885 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
8ae12a0d
DB		 1886 dynamic ? " (dynamic)" : "");
1887
ffbbdd21
LW		 1888 /* If we're using a queued driver, start the queue */
1889 if (master->transfer)
1890 dev_info(dev, "master is unqueued, this is deprecated\n");
1891 else {
1892 status = spi_master_initialize_queue(master);
1893 if (status) {
e93b0724 1894 device_del(&master->dev);
ffbbdd21
LW		 1895 goto done;
1896 }
1897 }
eca2ebc7
MS		 1898 /* add statistics */
1899 spin_lock_init(&master->statistics.lock);
ffbbdd21 1900
2b9603a0
FT		 1901 mutex_lock(&board_lock);
1902 list_add_tail(&master->list, &spi_master_list);
1903 list_for_each_entry(bi, &board_list, list)
1904 spi_match_master_to_boardinfo(master, &bi->board_info);
1905 mutex_unlock(&board_lock);
1906
64bee4d2 1907 /* Register devices from the device tree and ACPI */
12b15e83 1908 of_register_spi_devices(master);
64bee4d2 1909 acpi_register_spi_devices(master);
8ae12a0d
DB		 1910done:
1911 return status;
1912}
1913EXPORT_SYMBOL_GPL(spi_register_master);
1914
666d5b4c
MB		 1915static void devm_spi_unregister(struct device *dev, void *res)
1916{
1917 spi_unregister_master(*(struct spi_master **)res);
1918}
1919
1920/**
1921 * dev_spi_register_master - register managed SPI master controller
1922 * @dev: device managing SPI master
1923 * @master: initialized master, originally from spi_alloc_master()
1924 * Context: can sleep
1925 *
1926 * Register a SPI device as with spi_register_master() which will
1927 * automatically be unregister
97d56dc6
JMC		 1928 *
1929 * Return: zero on success, else a negative error code.
666d5b4c
MB		 1930 */
1931int devm_spi_register_master(struct device *dev, struct spi_master *master)
1932{
1933 struct spi_master **ptr;
1934 int ret;
1935
1936 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1937 if (!ptr)
1938 return -ENOMEM;
1939
1940 ret = spi_register_master(master);
4b92894e 1941 if (!ret) {
666d5b4c
MB		 1942 *ptr = master;
1943 devres_add(dev, ptr);
1944 } else {
1945 devres_free(ptr);
1946 }
1947
1948 return ret;
1949}
1950EXPORT_SYMBOL_GPL(devm_spi_register_master);
1951
34860089 1952static int __unregister(struct device *dev, void *null)
8ae12a0d 1953{
34860089 1954 spi_unregister_device(to_spi_device(dev));
8ae12a0d
DB		 1955 return 0;
1956}
1957
1958/**
1959 * spi_unregister_master - unregister SPI master controller
1960 * @master: the master being unregistered
33e34dc6 1961 * Context: can sleep
8ae12a0d
DB		 1962 *
1963 * This call is used only by SPI master controller drivers, which are the
1964 * only ones directly touching chip registers.
1965 *
1966 * This must be called from context that can sleep.
1967 */
1968void spi_unregister_master(struct spi_master *master)
1969{
89fc9a1a
JG		 1970 int dummy;
1971
ffbbdd21
LW		 1972 if (master->queued) {
1973 if (spi_destroy_queue(master))
1974 dev_err(&master->dev, "queue remove failed\n");
1975 }
1976
2b9603a0
FT		 1977 mutex_lock(&board_lock);
1978 list_del(&master->list);
1979 mutex_unlock(&board_lock);
1980
97dbf37d 1981 dummy = device_for_each_child(&master->dev, NULL, __unregister);
49dce689 1982 device_unregister(&master->dev);
8ae12a0d
DB		 1983}
1984EXPORT_SYMBOL_GPL(spi_unregister_master);
1985
ffbbdd21
LW		 1986int spi_master_suspend(struct spi_master *master)
1987{
1988 int ret;
1989
1990 /* Basically no-ops for non-queued masters */
1991 if (!master->queued)
1992 return 0;
1993
1994 ret = spi_stop_queue(master);
1995 if (ret)
1996 dev_err(&master->dev, "queue stop failed\n");
1997
1998 return ret;
1999}
2000EXPORT_SYMBOL_GPL(spi_master_suspend);
2001
2002int spi_master_resume(struct spi_master *master)
2003{
2004 int ret;
2005
2006 if (!master->queued)
2007 return 0;
2008
2009 ret = spi_start_queue(master);
2010 if (ret)
2011 dev_err(&master->dev, "queue restart failed\n");
2012
2013 return ret;
2014}
2015EXPORT_SYMBOL_GPL(spi_master_resume);
2016
9f3b795a 2017static int __spi_master_match(struct device *dev, const void *data)
5ed2c832
DY		 2018{
2019 struct spi_master *m;
9f3b795a 2020 const u16 *bus_num = data;
5ed2c832
DY		 2021
2022 m = container_of(dev, struct spi_master, dev);
2023 return m->bus_num == *bus_num;
2024}
2025
8ae12a0d
DB		 2026/**
2027 * spi_busnum_to_master - look up master associated with bus_num
2028 * @bus_num: the master's bus number
33e34dc6 2029 * Context: can sleep
8ae12a0d
DB		 2030 *
2031 * This call may be used with devices that are registered after
2032 * arch init time. It returns a refcounted pointer to the relevant
2033 * spi_master (which the caller must release), or NULL if there is
2034 * no such master registered.
97d56dc6
JMC		 2035 *
2036 * Return: the SPI master structure on success, else NULL.
8ae12a0d
DB		 2037 */
2038struct spi_master *spi_busnum_to_master(u16 bus_num)
2039{
49dce689 2040 struct device *dev;
1e9a51dc 2041 struct spi_master *master = NULL;
5ed2c832 2042
695794ae 2043 dev = class_find_device(&spi_master_class, NULL, &bus_num,
5ed2c832
DY		 2044 __spi_master_match);
2045 if (dev)
2046 master = container_of(dev, struct spi_master, dev);
2047 /* reference got in class_find_device */
1e9a51dc 2048 return master;
8ae12a0d
DB		 2049}
2050EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2051
d780c371
MS		 2052/*-------------------------------------------------------------------------*/
2053
2054/* Core methods for SPI resource management */
2055
2056/**
2057 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2058 * during the processing of a spi_message while using
2059 * spi_transfer_one
2060 * @spi: the spi device for which we allocate memory
2061 * @release: the release code to execute for this resource
2062 * @size: size to alloc and return
2063 * @gfp: GFP allocation flags
2064 *
2065 * Return: the pointer to the allocated data
2066 *
2067 * This may get enhanced in the future to allocate from a memory pool
2068 * of the @spi_device or @spi_master to avoid repeated allocations.
2069 */
2070void *spi_res_alloc(struct spi_device *spi,
2071 spi_res_release_t release,
2072 size_t size, gfp_t gfp)
2073{
2074 struct spi_res *sres;
2075
2076 sres = kzalloc(sizeof(*sres) + size, gfp);
2077 if (!sres)
2078 return NULL;
2079
2080 INIT_LIST_HEAD(&sres->entry);
2081 sres->release = release;
2082
2083 return sres->data;
2084}
2085EXPORT_SYMBOL_GPL(spi_res_alloc);
2086
2087/**
2088 * spi_res_free - free an spi resource
2089 * @res: pointer to the custom data of a resource
2090 *
2091 */
2092void spi_res_free(void *res)
2093{
2094 struct spi_res *sres = container_of(res, struct spi_res, data);
2095
2096 if (!res)
2097 return;
2098
2099 WARN_ON(!list_empty(&sres->entry));
2100 kfree(sres);
2101}
2102EXPORT_SYMBOL_GPL(spi_res_free);
2103
2104/**
2105 * spi_res_add - add a spi_res to the spi_message
2106 * @message: the spi message
2107 * @res: the spi_resource
2108 */
2109void spi_res_add(struct spi_message *message, void *res)
2110{
2111 struct spi_res *sres = container_of(res, struct spi_res, data);
2112
2113 WARN_ON(!list_empty(&sres->entry));
2114 list_add_tail(&sres->entry, &message->resources);
2115}
2116EXPORT_SYMBOL_GPL(spi_res_add);
2117
2118/**
2119 * spi_res_release - release all spi resources for this message
2120 * @master: the @spi_master
2121 * @message: the @spi_message
2122 */
2123void spi_res_release(struct spi_master *master,
2124 struct spi_message *message)
2125{
2126 struct spi_res *res;
2127
2128 while (!list_empty(&message->resources)) {
2129 res = list_last_entry(&message->resources,
2130 struct spi_res, entry);
2131
2132 if (res->release)
2133 res->release(master, message, res->data);
2134
2135 list_del(&res->entry);
2136
2137 kfree(res);
2138 }
2139}
2140EXPORT_SYMBOL_GPL(spi_res_release);
8ae12a0d
DB		 2141
2142/*-------------------------------------------------------------------------*/
2143
523baf5a
MS		 2144/* Core methods for spi_message alterations */
2145
2146static void __spi_replace_transfers_release(struct spi_master *master,
2147 struct spi_message *msg,
2148 void *res)
2149{
2150 struct spi_replaced_transfers *rxfer = res;
2151 size_t i;
2152
2153 /* call extra callback if requested */
2154 if (rxfer->release)
2155 rxfer->release(master, msg, res);
2156
2157 /* insert replaced transfers back into the message */
2158 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2159
2160 /* remove the formerly inserted entries */
2161 for (i = 0; i < rxfer->inserted; i++)
2162 list_del(&rxfer->inserted_transfers[i].transfer_list);
2163}
2164
2165/**
2166 * spi_replace_transfers - replace transfers with several transfers
2167 * and register change with spi_message.resources
2168 * @msg: the spi_message we work upon
2169 * @xfer_first: the first spi_transfer we want to replace
2170 * @remove: number of transfers to remove
2171 * @insert: the number of transfers we want to insert instead
2172 * @release: extra release code necessary in some circumstances
2173 * @extradatasize: extra data to allocate (with alignment guarantees
2174 * of struct @spi_transfer)
05885397 2175 * @gfp: gfp flags
523baf5a
MS		 2176 *
2177 * Returns: pointer to @spi_replaced_transfers,
2178 * PTR_ERR(...) in case of errors.
2179 */
2180struct spi_replaced_transfers *spi_replace_transfers(
2181 struct spi_message *msg,
2182 struct spi_transfer *xfer_first,
2183 size_t remove,
2184 size_t insert,
2185 spi_replaced_release_t release,
2186 size_t extradatasize,
2187 gfp_t gfp)
2188{
2189 struct spi_replaced_transfers *rxfer;
2190 struct spi_transfer *xfer;
2191 size_t i;
2192
2193 /* allocate the structure using spi_res */
2194 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2195 insert * sizeof(struct spi_transfer)
2196 + sizeof(struct spi_replaced_transfers)
2197 + extradatasize,
2198 gfp);
2199 if (!rxfer)
2200 return ERR_PTR(-ENOMEM);
2201
2202 /* the release code to invoke before running the generic release */
2203 rxfer->release = release;
2204
2205 /* assign extradata */
2206 if (extradatasize)
2207 rxfer->extradata =
2208 &rxfer->inserted_transfers[insert];
2209
2210 /* init the replaced_transfers list */
2211 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2212
2213 /* assign the list_entry after which we should reinsert
2214 * the @replaced_transfers - it may be spi_message.messages!
2215 */
2216 rxfer->replaced_after = xfer_first->transfer_list.prev;
2217
2218 /* remove the requested number of transfers */
2219 for (i = 0; i < remove; i++) {
2220 /* if the entry after replaced_after it is msg->transfers
2221 * then we have been requested to remove more transfers
2222 * than are in the list
2223 */
2224 if (rxfer->replaced_after->next == &msg->transfers) {
2225 dev_err(&msg->spi->dev,
2226 "requested to remove more spi_transfers than are available\n");
2227 /* insert replaced transfers back into the message */
2228 list_splice(&rxfer->replaced_transfers,
2229 rxfer->replaced_after);
2230
2231 /* free the spi_replace_transfer structure */
2232 spi_res_free(rxfer);
2233
2234 /* and return with an error */
2235 return ERR_PTR(-EINVAL);
2236 }
2237
2238 /* remove the entry after replaced_after from list of
2239 * transfers and add it to list of replaced_transfers
2240 */
2241 list_move_tail(rxfer->replaced_after->next,
2242 &rxfer->replaced_transfers);
2243 }
2244
2245 /* create copy of the given xfer with identical settings
2246 * based on the first transfer to get removed
2247 */
2248 for (i = 0; i < insert; i++) {
2249 /* we need to run in reverse order */
2250 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2251
2252 /* copy all spi_transfer data */
2253 memcpy(xfer, xfer_first, sizeof(*xfer));
2254
2255 /* add to list */
2256 list_add(&xfer->transfer_list, rxfer->replaced_after);
2257
2258 /* clear cs_change and delay_usecs for all but the last */
2259 if (i) {
2260 xfer->cs_change = false;
2261 xfer->delay_usecs = 0;
2262 }
2263 }
2264
2265 /* set up inserted */
2266 rxfer->inserted = insert;
2267
2268 /* and register it with spi_res/spi_message */
2269 spi_res_add(msg, rxfer);
2270
2271 return rxfer;
2272}
2273EXPORT_SYMBOL_GPL(spi_replace_transfers);
2274
08933418
FE		 2275static int __spi_split_transfer_maxsize(struct spi_master *master,
2276 struct spi_message *msg,
2277 struct spi_transfer **xferp,
2278 size_t maxsize,
2279 gfp_t gfp)
d9f12122
MS		 2280{
2281 struct spi_transfer *xfer = *xferp, *xfers;
2282 struct spi_replaced_transfers *srt;
2283 size_t offset;
2284 size_t count, i;
2285
2286 /* warn once about this fact that we are splitting a transfer */
2287 dev_warn_once(&msg->spi->dev,
7d62f51e 2288 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
d9f12122
MS		 2289 xfer->len, maxsize);
2290
2291 /* calculate how many we have to replace */
2292 count = DIV_ROUND_UP(xfer->len, maxsize);
2293
2294 /* create replacement */
2295 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
657d32ef
DC		 2296 if (IS_ERR(srt))
2297 return PTR_ERR(srt);
d9f12122
MS		 2298 xfers = srt->inserted_transfers;
2299
2300 /* now handle each of those newly inserted spi_transfers
2301 * note that the replacements spi_transfers all are preset
2302 * to the same values as *xferp, so tx_buf, rx_buf and len
2303 * are all identical (as well as most others)
2304 * so we just have to fix up len and the pointers.
2305 *
2306 * this also includes support for the depreciated
2307 * spi_message.is_dma_mapped interface
2308 */
2309
2310 /* the first transfer just needs the length modified, so we
2311 * run it outside the loop
2312 */
c8dab77a 2313 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
d9f12122
MS		 2314
2315 /* all the others need rx_buf/tx_buf also set */
2316 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2317 /* update rx_buf, tx_buf and dma */
2318 if (xfers[i].rx_buf)
2319 xfers[i].rx_buf += offset;
2320 if (xfers[i].rx_dma)
2321 xfers[i].rx_dma += offset;
2322 if (xfers[i].tx_buf)
2323 xfers[i].tx_buf += offset;
2324 if (xfers[i].tx_dma)
2325 xfers[i].tx_dma += offset;
2326
2327 /* update length */
2328 xfers[i].len = min(maxsize, xfers[i].len - offset);
2329 }
2330
2331 /* we set up xferp to the last entry we have inserted,
2332 * so that we skip those already split transfers
2333 */
2334 *xferp = &xfers[count - 1];
2335
2336 /* increment statistics counters */
2337 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2338 transfers_split_maxsize);
2339 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2340 transfers_split_maxsize);
2341
2342 return 0;
2343}
2344
2345/**
2346 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2347 * when an individual transfer exceeds a
2348 * certain size
2349 * @master: the @spi_master for this transfer
3700ce95
MI		 2350 * @msg: the @spi_message to transform
2351 * @maxsize: the maximum when to apply this
10f11a22 2352 * @gfp: GFP allocation flags
d9f12122
MS		 2353 *
2354 * Return: status of transformation
2355 */
2356int spi_split_transfers_maxsize(struct spi_master *master,
2357 struct spi_message *msg,
2358 size_t maxsize,
2359 gfp_t gfp)
2360{
2361 struct spi_transfer *xfer;
2362 int ret;
2363
2364 /* iterate over the transfer_list,
2365 * but note that xfer is advanced to the last transfer inserted
2366 * to avoid checking sizes again unnecessarily (also xfer does
2367 * potentiall belong to a different list by the time the
2368 * replacement has happened
2369 */
2370 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2371 if (xfer->len > maxsize) {
2372 ret = __spi_split_transfer_maxsize(
2373 master, msg, &xfer, maxsize, gfp);
2374 if (ret)
2375 return ret;
2376 }
2377 }
2378
2379 return 0;
2380}
2381EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
8ae12a0d
DB		 2382
2383/*-------------------------------------------------------------------------*/
2384
7d077197
DB		 2385/* Core methods for SPI master protocol drivers. Some of the
2386 * other core methods are currently defined as inline functions.
2387 */
2388
63ab645f
SB		 2389static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2390{
2391 if (master->bits_per_word_mask) {
2392 /* Only 32 bits fit in the mask */
2393 if (bits_per_word > 32)
2394 return -EINVAL;
2395 if (!(master->bits_per_word_mask &
2396 SPI_BPW_MASK(bits_per_word)))
2397 return -EINVAL;
2398 }
2399
2400 return 0;
2401}
2402
7d077197
DB		 2403/**
2404 * spi_setup - setup SPI mode and clock rate
2405 * @spi: the device whose settings are being modified
2406 * Context: can sleep, and no requests are queued to the device
2407 *
2408 * SPI protocol drivers may need to update the transfer mode if the
2409 * device doesn't work with its default. They may likewise need
2410 * to update clock rates or word sizes from initial values. This function
2411 * changes those settings, and must be called from a context that can sleep.
2412 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2413 * effect the next time the device is selected and data is transferred to
2414 * or from it. When this function returns, the spi device is deselected.
2415 *
2416 * Note that this call will fail if the protocol driver specifies an option
2417 * that the underlying controller or its driver does not support. For
2418 * example, not all hardware supports wire transfers using nine bit words,
2419 * LSB-first wire encoding, or active-high chipselects.
97d56dc6
JMC		 2420 *
2421 * Return: zero on success, else a negative error code.
7d077197
DB		 2422 */
2423int spi_setup(struct spi_device *spi)
2424{
83596fbe 2425 unsigned bad_bits, ugly_bits;
5ab8d262 2426 int status;
7d077197 2427
f477b7fb 2428 /* check mode to prevent that DUAL and QUAD set at the same time
2429 */
2430 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2431 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2432 dev_err(&spi->dev,
2433 "setup: can not select dual and quad at the same time\n");
2434 return -EINVAL;
2435 }
2436 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2437 */
2438 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2439 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2440 return -EINVAL;
e7db06b5
DB		 2441 /* help drivers fail *cleanly* when they need options
2442 * that aren't supported with their current master
2443 */
2444 bad_bits = spi->mode & ~spi->master->mode_bits;
83596fbe
GU		 2445 ugly_bits = bad_bits &
2446 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2447 if (ugly_bits) {
2448 dev_warn(&spi->dev,
2449 "setup: ignoring unsupported mode bits %x\n",
2450 ugly_bits);
2451 spi->mode &= ~ugly_bits;
2452 bad_bits &= ~ugly_bits;
2453 }
e7db06b5 2454 if (bad_bits) {
eb288a1f 2455 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
e7db06b5
DB		 2456 bad_bits);
2457 return -EINVAL;
2458 }
2459
7d077197
DB		 2460 if (!spi->bits_per_word)
2461 spi->bits_per_word = 8;
2462
5ab8d262
AS		 2463 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2464 if (status)
2465 return status;
63ab645f 2466
052eb2d4
AL		 2467 if (!spi->max_speed_hz)
2468 spi->max_speed_hz = spi->master->max_speed_hz;
2469
caae070c
LD		 2470 if (spi->master->setup)
2471 status = spi->master->setup(spi);
7d077197 2472
abeedb01
FCJ		 2473 spi_set_cs(spi, false);
2474
5fe5f05e 2475 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
7d077197
DB		 2476 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2477 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2478 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2479 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2480 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2481 spi->bits_per_word, spi->max_speed_hz,
2482 status);
2483
2484 return status;
2485}
2486EXPORT_SYMBOL_GPL(spi_setup);
2487
90808738 2488static int __spi_validate(struct spi_device *spi, struct spi_message *message)
cf32b71e
ES		 2489{
2490 struct spi_master *master = spi->master;
e6811d1d 2491 struct spi_transfer *xfer;
6ea31293 2492 int w_size;
cf32b71e 2493
24a0013a
MB		 2494 if (list_empty(&message->transfers))
2495 return -EINVAL;
24a0013a 2496
cf32b71e
ES		 2497 /* Half-duplex links include original MicroWire, and ones with
2498 * only one data pin like SPI_3WIRE (switches direction) or where
2499 * either MOSI or MISO is missing. They can also be caused by
2500 * software limitations.
2501 */
2502 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2503 || (spi->mode & SPI_3WIRE)) {
cf32b71e
ES		 2504 unsigned flags = master->flags;
2505
2506 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2507 if (xfer->rx_buf && xfer->tx_buf)
2508 return -EINVAL;
2509 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2510 return -EINVAL;
2511 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2512 return -EINVAL;
2513 }
2514 }
2515
e6811d1d 2516 /**
059b8ffe
LD		 2517 * Set transfer bits_per_word and max speed as spi device default if
2518 * it is not set for this transfer.
f477b7fb 2519 * Set transfer tx_nbits and rx_nbits as single transfer default
2520 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
e6811d1d 2521 */
77e80588 2522 message->frame_length = 0;
e6811d1d 2523 list_for_each_entry(xfer, &message->transfers, transfer_list) {
078726ce 2524 message->frame_length += xfer->len;
e6811d1d
LD		 2525 if (!xfer->bits_per_word)
2526 xfer->bits_per_word = spi->bits_per_word;
a6f87fad
AL		 2527
2528 if (!xfer->speed_hz)
059b8ffe 2529 xfer->speed_hz = spi->max_speed_hz;
7dc9fbc3
MB		 2530 if (!xfer->speed_hz)
2531 xfer->speed_hz = master->max_speed_hz;
a6f87fad
AL		 2532
2533 if (master->max_speed_hz &&
2534 xfer->speed_hz > master->max_speed_hz)
2535 xfer->speed_hz = master->max_speed_hz;
56ede94a 2536
63ab645f
SB		 2537 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2538 return -EINVAL;
a2fd4f9f 2539
4d94bd21
II		 2540 /*
2541 * SPI transfer length should be multiple of SPI word size
2542 * where SPI word size should be power-of-two multiple
2543 */
2544 if (xfer->bits_per_word <= 8)
2545 w_size = 1;
2546 else if (xfer->bits_per_word <= 16)
2547 w_size = 2;
2548 else
2549 w_size = 4;
2550
4d94bd21 2551 /* No partial transfers accepted */
6ea31293 2552 if (xfer->len % w_size)
4d94bd21
II		 2553 return -EINVAL;
2554
a2fd4f9f
MB		 2555 if (xfer->speed_hz && master->min_speed_hz &&
2556 xfer->speed_hz < master->min_speed_hz)
2557 return -EINVAL;
f477b7fb 2558
2559 if (xfer->tx_buf && !xfer->tx_nbits)
2560 xfer->tx_nbits = SPI_NBITS_SINGLE;
2561 if (xfer->rx_buf && !xfer->rx_nbits)
2562 xfer->rx_nbits = SPI_NBITS_SINGLE;
2563 /* check transfer tx/rx_nbits:
1afd9989
GU		 2564 * 1. check the value matches one of single, dual and quad
2565 * 2. check tx/rx_nbits match the mode in spi_device
f477b7fb 2566 */
db90a441
SP		 2567 if (xfer->tx_buf) {
2568 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2569 xfer->tx_nbits != SPI_NBITS_DUAL &&
2570 xfer->tx_nbits != SPI_NBITS_QUAD)
2571 return -EINVAL;
2572 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2573 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2574 return -EINVAL;
2575 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2576 !(spi->mode & SPI_TX_QUAD))
2577 return -EINVAL;
db90a441 2578 }
f477b7fb 2579 /* check transfer rx_nbits */
db90a441
SP		 2580 if (xfer->rx_buf) {
2581 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2582 xfer->rx_nbits != SPI_NBITS_DUAL &&
2583 xfer->rx_nbits != SPI_NBITS_QUAD)
2584 return -EINVAL;
2585 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2586 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2587 return -EINVAL;
2588 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2589 !(spi->mode & SPI_RX_QUAD))
2590 return -EINVAL;
db90a441 2591 }
e6811d1d
LD		 2592 }
2593
cf32b71e 2594 message->status = -EINPROGRESS;
90808738
MB		 2595
2596 return 0;
2597}
2598
2599static int __spi_async(struct spi_device *spi, struct spi_message *message)
2600{
2601 struct spi_master *master = spi->master;
2602
2603 message->spi = spi;
2604
eca2ebc7
MS		 2605 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2606 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2607
90808738
MB		 2608 trace_spi_message_submit(message);
2609
cf32b71e
ES		 2610 return master->transfer(spi, message);
2611}
2612
568d0697
DB		 2613/**
2614 * spi_async - asynchronous SPI transfer
2615 * @spi: device with which data will be exchanged
2616 * @message: describes the data transfers, including completion callback
2617 * Context: any (irqs may be blocked, etc)
2618 *
2619 * This call may be used in_irq and other contexts which can't sleep,
2620 * as well as from task contexts which can sleep.
2621 *
2622 * The completion callback is invoked in a context which can't sleep.
2623 * Before that invocation, the value of message->status is undefined.
2624 * When the callback is issued, message->status holds either zero (to
2625 * indicate complete success) or a negative error code. After that
2626 * callback returns, the driver which issued the transfer request may
2627 * deallocate the associated memory; it's no longer in use by any SPI
2628 * core or controller driver code.
2629 *
2630 * Note that although all messages to a spi_device are handled in
2631 * FIFO order, messages may go to different devices in other orders.
2632 * Some device might be higher priority, or have various "hard" access
2633 * time requirements, for example.
2634 *
2635 * On detection of any fault during the transfer, processing of
2636 * the entire message is aborted, and the device is deselected.
2637 * Until returning from the associated message completion callback,
2638 * no other spi_message queued to that device will be processed.
2639 * (This rule applies equally to all the synchronous transfer calls,
2640 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2641 *
2642 * Return: zero on success, else a negative error code.
568d0697
DB		 2643 */
2644int spi_async(struct spi_device *spi, struct spi_message *message)
2645{
2646 struct spi_master *master = spi->master;
cf32b71e
ES		 2647 int ret;
2648 unsigned long flags;
568d0697 2649
90808738
MB		 2650 ret = __spi_validate(spi, message);
2651 if (ret != 0)
2652 return ret;
2653
cf32b71e 2654 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
568d0697 2655
cf32b71e
ES		 2656 if (master->bus_lock_flag)
2657 ret = -EBUSY;
2658 else
2659 ret = __spi_async(spi, message);
568d0697 2660
cf32b71e
ES		 2661 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2662
2663 return ret;
568d0697
DB		 2664}
2665EXPORT_SYMBOL_GPL(spi_async);
2666
cf32b71e
ES		 2667/**
2668 * spi_async_locked - version of spi_async with exclusive bus usage
2669 * @spi: device with which data will be exchanged
2670 * @message: describes the data transfers, including completion callback
2671 * Context: any (irqs may be blocked, etc)
2672 *
2673 * This call may be used in_irq and other contexts which can't sleep,
2674 * as well as from task contexts which can sleep.
2675 *
2676 * The completion callback is invoked in a context which can't sleep.
2677 * Before that invocation, the value of message->status is undefined.
2678 * When the callback is issued, message->status holds either zero (to
2679 * indicate complete success) or a negative error code. After that
2680 * callback returns, the driver which issued the transfer request may
2681 * deallocate the associated memory; it's no longer in use by any SPI
2682 * core or controller driver code.
2683 *
2684 * Note that although all messages to a spi_device are handled in
2685 * FIFO order, messages may go to different devices in other orders.
2686 * Some device might be higher priority, or have various "hard" access
2687 * time requirements, for example.
2688 *
2689 * On detection of any fault during the transfer, processing of
2690 * the entire message is aborted, and the device is deselected.
2691 * Until returning from the associated message completion callback,
2692 * no other spi_message queued to that device will be processed.
2693 * (This rule applies equally to all the synchronous transfer calls,
2694 * which are wrappers around this core asynchronous primitive.)
97d56dc6
JMC		 2695 *
2696 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2697 */
2698int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2699{
2700 struct spi_master *master = spi->master;
2701 int ret;
2702 unsigned long flags;
2703
90808738
MB		 2704 ret = __spi_validate(spi, message);
2705 if (ret != 0)
2706 return ret;
2707
cf32b71e
ES		 2708 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2709
2710 ret = __spi_async(spi, message);
2711
2712 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2713
2714 return ret;
2715
2716}
2717EXPORT_SYMBOL_GPL(spi_async_locked);
2718
7d077197 2719
556351f1
V		 2720int spi_flash_read(struct spi_device *spi,
2721 struct spi_flash_read_message *msg)
2722
2723{
2724 struct spi_master *master = spi->master;
2725 int ret;
2726
2727 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2728 msg->addr_nbits == SPI_NBITS_DUAL) &&
2729 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2730 return -EINVAL;
2731 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2732 msg->addr_nbits == SPI_NBITS_QUAD) &&
2733 !(spi->mode & SPI_TX_QUAD))
2734 return -EINVAL;
2735 if (msg->data_nbits == SPI_NBITS_DUAL &&
2736 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2737 return -EINVAL;
2738 if (msg->data_nbits == SPI_NBITS_QUAD &&
2739 !(spi->mode & SPI_RX_QUAD))
2740 return -EINVAL;
2741
2742 if (master->auto_runtime_pm) {
2743 ret = pm_runtime_get_sync(master->dev.parent);
2744 if (ret < 0) {
2745 dev_err(&master->dev, "Failed to power device: %d\n",
2746 ret);
2747 return ret;
2748 }
2749 }
2750 mutex_lock(&master->bus_lock_mutex);
2751 ret = master->spi_flash_read(spi, msg);
2752 mutex_unlock(&master->bus_lock_mutex);
2753 if (master->auto_runtime_pm)
2754 pm_runtime_put(master->dev.parent);
2755
2756 return ret;
2757}
2758EXPORT_SYMBOL_GPL(spi_flash_read);
2759
7d077197
DB		 2760/*-------------------------------------------------------------------------*/
2761
2762/* Utility methods for SPI master protocol drivers, layered on
2763 * top of the core. Some other utility methods are defined as
2764 * inline functions.
2765 */
2766
5d870c8e
AM		 2767static void spi_complete(void *arg)
2768{
2769 complete(arg);
2770}
2771
cf32b71e
ES		 2772static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2773 int bus_locked)
2774{
2775 DECLARE_COMPLETION_ONSTACK(done);
2776 int status;
2777 struct spi_master *master = spi->master;
0461a414
MB		 2778 unsigned long flags;
2779
2780 status = __spi_validate(spi, message);
2781 if (status != 0)
2782 return status;
cf32b71e
ES		 2783
2784 message->complete = spi_complete;
2785 message->context = &done;
0461a414 2786 message->spi = spi;
cf32b71e 2787
eca2ebc7
MS		 2788 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2789 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2790
cf32b71e
ES		 2791 if (!bus_locked)
2792 mutex_lock(&master->bus_lock_mutex);
2793
0461a414
MB		 2794 /* If we're not using the legacy transfer method then we will
2795 * try to transfer in the calling context so special case.
2796 * This code would be less tricky if we could remove the
2797 * support for driver implemented message queues.
2798 */
2799 if (master->transfer == spi_queued_transfer) {
2800 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2801
2802 trace_spi_message_submit(message);
2803
2804 status = __spi_queued_transfer(spi, message, false);
2805
2806 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2807 } else {
2808 status = spi_async_locked(spi, message);
2809 }
cf32b71e
ES		 2810
2811 if (!bus_locked)
2812 mutex_unlock(&master->bus_lock_mutex);
2813
2814 if (status == 0) {
0461a414
MB		 2815 /* Push out the messages in the calling context if we
2816 * can.
2817 */
eca2ebc7
MS		 2818 if (master->transfer == spi_queued_transfer) {
2819 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2820 spi_sync_immediate);
2821 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2822 spi_sync_immediate);
49023d2e 2823 __spi_pump_messages(master, false, bus_locked);
eca2ebc7 2824 }
0461a414 2825
cf32b71e
ES		 2826 wait_for_completion(&done);
2827 status = message->status;
2828 }
2829 message->context = NULL;
2830 return status;
2831}
2832
8ae12a0d
DB		 2833/**
2834 * spi_sync - blocking/synchronous SPI data transfers
2835 * @spi: device with which data will be exchanged
2836 * @message: describes the data transfers
33e34dc6 2837 * Context: can sleep
8ae12a0d
DB		 2838 *
2839 * This call may only be used from a context that may sleep. The sleep
2840 * is non-interruptible, and has no timeout. Low-overhead controller
2841 * drivers may DMA directly into and out of the message buffers.
2842 *
2843 * Note that the SPI device's chip select is active during the message,
2844 * and then is normally disabled between messages. Drivers for some
2845 * frequently-used devices may want to minimize costs of selecting a chip,
2846 * by leaving it selected in anticipation that the next message will go
2847 * to the same chip. (That may increase power usage.)
2848 *
0c868461
DB		 2849 * Also, the caller is guaranteeing that the memory associated with the
2850 * message will not be freed before this call returns.
2851 *
97d56dc6 2852 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2853 */
2854int spi_sync(struct spi_device *spi, struct spi_message *message)
2855{
24c8cd1b 2856 return __spi_sync(spi, message, spi->master->bus_lock_flag);
8ae12a0d
DB		 2857}
2858EXPORT_SYMBOL_GPL(spi_sync);
2859
cf32b71e
ES		 2860/**
2861 * spi_sync_locked - version of spi_sync with exclusive bus usage
2862 * @spi: device with which data will be exchanged
2863 * @message: describes the data transfers
2864 * Context: can sleep
2865 *
2866 * This call may only be used from a context that may sleep. The sleep
2867 * is non-interruptible, and has no timeout. Low-overhead controller
2868 * drivers may DMA directly into and out of the message buffers.
2869 *
2870 * This call should be used by drivers that require exclusive access to the
25985edc 2871 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
cf32b71e
ES		 2872 * be released by a spi_bus_unlock call when the exclusive access is over.
2873 *
97d56dc6 2874 * Return: zero on success, else a negative error code.
cf32b71e
ES		 2875 */
2876int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2877{
2878 return __spi_sync(spi, message, 1);
2879}
2880EXPORT_SYMBOL_GPL(spi_sync_locked);
2881
2882/**
2883 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2884 * @master: SPI bus master that should be locked for exclusive bus access
2885 * Context: can sleep
2886 *
2887 * This call may only be used from a context that may sleep. The sleep
2888 * is non-interruptible, and has no timeout.
2889 *
2890 * This call should be used by drivers that require exclusive access to the
2891 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2892 * exclusive access is over. Data transfer must be done by spi_sync_locked
2893 * and spi_async_locked calls when the SPI bus lock is held.
2894 *
97d56dc6 2895 * Return: always zero.
cf32b71e
ES		 2896 */
2897int spi_bus_lock(struct spi_master *master)
2898{
2899 unsigned long flags;
2900
2901 mutex_lock(&master->bus_lock_mutex);
2902
2903 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2904 master->bus_lock_flag = 1;
2905 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2906
2907 /* mutex remains locked until spi_bus_unlock is called */
2908
2909 return 0;
2910}
2911EXPORT_SYMBOL_GPL(spi_bus_lock);
2912
2913/**
2914 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2915 * @master: SPI bus master that was locked for exclusive bus access
2916 * Context: can sleep
2917 *
2918 * This call may only be used from a context that may sleep. The sleep
2919 * is non-interruptible, and has no timeout.
2920 *
2921 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2922 * call.
2923 *
97d56dc6 2924 * Return: always zero.
cf32b71e
ES		 2925 */
2926int spi_bus_unlock(struct spi_master *master)
2927{
2928 master->bus_lock_flag = 0;
2929
2930 mutex_unlock(&master->bus_lock_mutex);
2931
2932 return 0;
2933}
2934EXPORT_SYMBOL_GPL(spi_bus_unlock);
2935
a9948b61 2936/* portable code must never pass more than 32 bytes */
5fe5f05e 2937#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
8ae12a0d
DB		 2938
2939static u8 *buf;
2940
2941/**
2942 * spi_write_then_read - SPI synchronous write followed by read
2943 * @spi: device with which data will be exchanged
2944 * @txbuf: data to be written (need not be dma-safe)
2945 * @n_tx: size of txbuf, in bytes
27570497
JP		 2946 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2947 * @n_rx: size of rxbuf, in bytes
33e34dc6 2948 * Context: can sleep
8ae12a0d
DB		 2949 *
2950 * This performs a half duplex MicroWire style transaction with the
2951 * device, sending txbuf and then reading rxbuf. The return value
2952 * is zero for success, else a negative errno status code.
b885244e 2953 * This call may only be used from a context that may sleep.
8ae12a0d 2954 *
0c868461 2955 * Parameters to this routine are always copied using a small buffer;
33e34dc6
DB		 2956 * portable code should never use this for more than 32 bytes.
2957 * Performance-sensitive or bulk transfer code should instead use
0c868461 2958 * spi_{async,sync}() calls with dma-safe buffers.
97d56dc6
JMC		 2959 *
2960 * Return: zero on success, else a negative error code.
8ae12a0d
DB		 2961 */
2962int spi_write_then_read(struct spi_device *spi,
0c4a1590
MB		 2963 const void *txbuf, unsigned n_tx,
2964 void *rxbuf, unsigned n_rx)
8ae12a0d 2965{
068f4070 2966 static DEFINE_MUTEX(lock);
8ae12a0d
DB		 2967
2968 int status;
2969 struct spi_message message;
bdff549e 2970 struct spi_transfer x[2];
8ae12a0d
DB		 2971 u8 *local_buf;
2972
b3a223ee
MB		 2973 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2974 * copying here, (as a pure convenience thing), but we can
2975 * keep heap costs out of the hot path unless someone else is
2976 * using the pre-allocated buffer or the transfer is too large.
8ae12a0d 2977 */
b3a223ee 2978 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
2cd94c8a
MB		 2979 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2980 GFP_KERNEL | GFP_DMA);
b3a223ee
MB		 2981 if (!local_buf)
2982 return -ENOMEM;
2983 } else {
2984 local_buf = buf;
2985 }
8ae12a0d 2986
8275c642 2987 spi_message_init(&message);
5fe5f05e 2988 memset(x, 0, sizeof(x));
bdff549e
DB		 2989 if (n_tx) {
2990 x[0].len = n_tx;
2991 spi_message_add_tail(&x[0], &message);
2992 }
2993 if (n_rx) {
2994 x[1].len = n_rx;
2995 spi_message_add_tail(&x[1], &message);
2996 }
8275c642 2997
8ae12a0d 2998 memcpy(local_buf, txbuf, n_tx);
bdff549e
DB		 2999 x[0].tx_buf = local_buf;
3000 x[1].rx_buf = local_buf + n_tx;
8ae12a0d
DB		 3001
3002 /* do the i/o */
8ae12a0d 3003 status = spi_sync(spi, &message);
9b938b74 3004 if (status == 0)
bdff549e 3005 memcpy(rxbuf, x[1].rx_buf, n_rx);
8ae12a0d 3006
bdff549e 3007 if (x[0].tx_buf == buf)
068f4070 3008 mutex_unlock(&lock);
8ae12a0d
DB		 3009 else
3010 kfree(local_buf);
3011
3012 return status;
3013}
3014EXPORT_SYMBOL_GPL(spi_write_then_read);
3015
3016/*-------------------------------------------------------------------------*/
3017
ce79d54a
PA		 3018#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3019static int __spi_of_device_match(struct device *dev, void *data)
3020{
3021 return dev->of_node == data;
3022}
3023
3024/* must call put_device() when done with returned spi_device device */
3025static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3026{
3027 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3028 __spi_of_device_match);
3029 return dev ? to_spi_device(dev) : NULL;
3030}
3031
3032static int __spi_of_master_match(struct device *dev, const void *data)
3033{
3034 return dev->of_node == data;
3035}
3036
3037/* the spi masters are not using spi_bus, so we find it with another way */
3038static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3039{
3040 struct device *dev;
3041
3042 dev = class_find_device(&spi_master_class, NULL, node,
3043 __spi_of_master_match);
3044 if (!dev)
3045 return NULL;
3046
3047 /* reference got in class_find_device */
3048 return container_of(dev, struct spi_master, dev);
3049}
3050
3051static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3052 void *arg)
3053{
3054 struct of_reconfig_data *rd = arg;
3055 struct spi_master *master;
3056 struct spi_device *spi;
3057
3058 switch (of_reconfig_get_state_change(action, arg)) {
3059 case OF_RECONFIG_CHANGE_ADD:
3060 master = of_find_spi_master_by_node(rd->dn->parent);
3061 if (master == NULL)
3062 return NOTIFY_OK; /* not for us */
3063
bd6c1644
GU		 3064 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3065 put_device(&master->dev);
3066 return NOTIFY_OK;
3067 }
3068
ce79d54a
PA		 3069 spi = of_register_spi_device(master, rd->dn);
3070 put_device(&master->dev);
3071
3072 if (IS_ERR(spi)) {
3073 pr_err("%s: failed to create for '%s'\n",
3074 __func__, rd->dn->full_name);
3075 return notifier_from_errno(PTR_ERR(spi));
3076 }
3077 break;
3078
3079 case OF_RECONFIG_CHANGE_REMOVE:
bd6c1644
GU		 3080 /* already depopulated? */
3081 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3082 return NOTIFY_OK;
3083
ce79d54a
PA		 3084 /* find our device by node */
3085 spi = of_find_spi_device_by_node(rd->dn);
3086 if (spi == NULL)
3087 return NOTIFY_OK; /* no? not meant for us */
3088
3089 /* unregister takes one ref away */
3090 spi_unregister_device(spi);
3091
3092 /* and put the reference of the find */
3093 put_device(&spi->dev);
3094 break;
3095 }
3096
3097 return NOTIFY_OK;
3098}
3099
3100static struct notifier_block spi_of_notifier = {
3101 .notifier_call = of_spi_notify,
3102};
3103#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3104extern struct notifier_block spi_of_notifier;
3105#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3106
8ae12a0d
DB		 3107static int __init spi_init(void)
3108{
b885244e
DB		 3109 int status;
3110
e94b1766 3111 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
b885244e
DB		 3112 if (!buf) {
3113 status = -ENOMEM;
3114 goto err0;
3115 }
3116
3117 status = bus_register(&spi_bus_type);
3118 if (status < 0)
3119 goto err1;
8ae12a0d 3120
b885244e
DB		 3121 status = class_register(&spi_master_class);
3122 if (status < 0)
3123 goto err2;
ce79d54a 3124
5267720e 3125 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
ce79d54a
PA		 3126 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3127
8ae12a0d 3128 return 0;
b885244e
DB		 3129
3130err2:
3131 bus_unregister(&spi_bus_type);
3132err1:
3133 kfree(buf);
3134 buf = NULL;
3135err0:
3136 return status;
8ae12a0d 3137}
b885244e 3138
8ae12a0d
DB		 3139/* board_info is normally registered in arch_initcall(),
3140 * but even essential drivers wait till later
b885244e
DB		 3141 *
3142 * REVISIT only boardinfo really needs static linking. the rest (device and
3143 * driver registration) _could_ be dynamically linked (modular) ... costs
3144 * include needing to have boardinfo data structures be much more public.
8ae12a0d 3145 */
673c0c00 3146postcore_initcall(spi_init);
8ae12a0d 3147
Linux 6.x block layer and io_uring tree(s)