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David Brownell8ae12a02006-01-08 13:34:19 -08001/*
Grant Likelyca632f52011-06-06 01:16:30 -06002 * SPI init/core code
David Brownell8ae12a02006-01-08 13:34:19 -08003 *
4 * Copyright (C) 2005 David Brownell
Grant Likelyd57a4282012-04-07 14:16:53 -06005 * Copyright (C) 2008 Secret Lab Technologies Ltd.
David Brownell8ae12a02006-01-08 13:34:19 -08006 *
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.
David Brownell8ae12a02006-01-08 13:34:19 -080016 */
17
David Brownell8ae12a02006-01-08 13:34:19 -080018#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/cache.h>
Mark Brown99adef32014-01-16 12:22:43 +000022#include <linux/dma-mapping.h>
23#include <linux/dmaengine.h>
Matthias Kaehlcke94040822007-07-17 04:04:16 -070024#include <linux/mutex.h>
Sinan Akman2b7a32f2010-10-02 21:28:29 -060025#include <linux/of_device.h>
Grant Likelyd57a4282012-04-07 14:16:53 -060026#include <linux/of_irq.h>
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020027#include <linux/clk/clk-conf.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Anton Vorontsove0626e32009-09-22 16:46:08 -070029#include <linux/mod_devicetable.h>
David Brownell8ae12a02006-01-08 13:34:19 -080030#include <linux/spi/spi.h>
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +010031#include <linux/of_gpio.h>
Mark Brown3ae22e82010-12-25 15:32:27 +010032#include <linux/pm_runtime.h>
Ulf Hanssonf48c7672014-09-29 13:58:47 +020033#include <linux/pm_domain.h>
Paul Gortmaker025ed132011-07-10 12:57:55 -040034#include <linux/export.h>
Clark Williams8bd75c72013-02-07 09:47:07 -060035#include <linux/sched/rt.h>
Linus Walleijffbbdd212012-02-22 10:05:38 +010036#include <linux/delay.h>
37#include <linux/kthread.h>
Mika Westerberg64bee4d2012-11-30 12:37:53 +010038#include <linux/ioport.h>
39#include <linux/acpi.h>
David Brownell8ae12a02006-01-08 13:34:19 -080040
Mark Brown56ec1972013-10-07 19:33:53 +010041#define CREATE_TRACE_POINTS
42#include <trace/events/spi.h>
43
David Brownell8ae12a02006-01-08 13:34:19 -080044static void spidev_release(struct device *dev)
45{
Hans-Peter Nilsson0ffa0282007-02-12 00:52:45 -080046 struct spi_device *spi = to_spi_device(dev);
David Brownell8ae12a02006-01-08 13:34:19 -080047
48 /* spi masters may cleanup for released devices */
49 if (spi->master->cleanup)
50 spi->master->cleanup(spi);
51
David Brownell0c868462006-01-08 13:34:25 -080052 spi_master_put(spi->master);
Roman Tereshonkov07a389f2010-04-12 09:56:35 +000053 kfree(spi);
David Brownell8ae12a02006-01-08 13:34:19 -080054}
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);
Zhang Rui8c4ff6d2014-01-14 16:46:37 +080060 int len;
61
62 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
63 if (len != -ENODEV)
64 return len;
David Brownell8ae12a02006-01-08 13:34:19 -080065
Grant Likelyd8e328b2012-05-20 00:08:13 -060066 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
David Brownell8ae12a02006-01-08 13:34:19 -080067}
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -070068static DEVICE_ATTR_RO(modalias);
David Brownell8ae12a02006-01-08 13:34:19 -080069
Martin Sperleca2ebc2015-06-22 13:00:36 +000070#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{ \
Geliang Tangd1eba932015-12-23 00:18:41 +080087 struct spi_device *spi = to_spi_device(dev); \
Martin Sperleca2ebc2015-06-22 13:00:36 +000088 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
Martin Sperl6b7bc062015-06-22 13:02:04 +0000125#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
Martin Sperld9f12122015-12-14 15:20:20 +0000147SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
148
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -0700149static struct attribute *spi_dev_attrs[] = {
150 &dev_attr_modalias.attr,
151 NULL,
David Brownell8ae12a02006-01-08 13:34:19 -0800152};
Martin Sperleca2ebc2015-06-22 13:00:36 +0000153
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,
Martin Sperl6b7bc062015-06-22 13:02:04 +0000169 &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,
Martin Sperld9f12122015-12-14 15:20:20 +0000186 &dev_attr_spi_device_transfers_split_maxsize.attr,
Martin Sperleca2ebc2015-06-22 13:00:36 +0000187 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,
Martin Sperl6b7bc062015-06-22 13:02:04 +0000212 &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,
Martin Sperld9f12122015-12-14 15:20:20 +0000229 &dev_attr_spi_master_transfers_split_maxsize.attr,
Martin Sperleca2ebc2015-06-22 13:00:36 +0000230 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;
Martin Sperl6b7bc062015-06-22 13:02:04 +0000248 int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
249
250 if (l2len < 0)
251 l2len = 0;
Martin Sperleca2ebc2015-06-22 13:00:36 +0000252
253 spin_lock_irqsave(&stats->lock, flags);
254
255 stats->transfers++;
Martin Sperl6b7bc062015-06-22 13:02:04 +0000256 stats->transfer_bytes_histo[l2len]++;
Martin Sperleca2ebc2015-06-22 13:00:36 +0000257
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);
David Brownell8ae12a02006-01-08 13:34:19 -0800269
270/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
271 * and the sysfs version makes coldplug work too.
272 */
273
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700274static 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
David Brownell8ae12a02006-01-08 13:34:19 -0800293static int spi_match_device(struct device *dev, struct device_driver *drv)
294{
295 const struct spi_device *spi = to_spi_device(dev);
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700296 const struct spi_driver *sdrv = to_spi_driver(drv);
297
Sinan Akman2b7a32f2010-10-02 21:28:29 -0600298 /* Attempt an OF style match */
299 if (of_driver_match_device(dev, drv))
300 return 1;
301
Mika Westerberg64bee4d2012-11-30 12:37:53 +0100302 /* Then try ACPI */
303 if (acpi_driver_match_device(dev, drv))
304 return 1;
305
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700306 if (sdrv->id_table)
307 return !!spi_match_id(sdrv->id_table, spi);
David Brownell8ae12a02006-01-08 13:34:19 -0800308
Kay Sievers35f74fc2009-01-06 10:44:37 -0800309 return strcmp(spi->modalias, drv->name) == 0;
David Brownell8ae12a02006-01-08 13:34:19 -0800310}
311
Kay Sievers7eff2e72007-08-14 15:15:12 +0200312static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
David Brownell8ae12a02006-01-08 13:34:19 -0800313{
314 const struct spi_device *spi = to_spi_device(dev);
Zhang Rui8c4ff6d2014-01-14 16:46:37 +0800315 int rc;
316
317 rc = acpi_device_uevent_modalias(dev, env);
318 if (rc != -ENODEV)
319 return rc;
David Brownell8ae12a02006-01-08 13:34:19 -0800320
Anton Vorontsove0626e32009-09-22 16:46:08 -0700321 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
David Brownell8ae12a02006-01-08 13:34:19 -0800322 return 0;
323}
324
David Brownell8ae12a02006-01-08 13:34:19 -0800325struct bus_type spi_bus_type = {
326 .name = "spi",
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -0700327 .dev_groups = spi_dev_groups,
David Brownell8ae12a02006-01-08 13:34:19 -0800328 .match = spi_match_device,
329 .uevent = spi_uevent,
David Brownell8ae12a02006-01-08 13:34:19 -0800330};
331EXPORT_SYMBOL_GPL(spi_bus_type);
332
David Brownellb8852442006-01-08 13:34:23 -0800333
334static int spi_drv_probe(struct device *dev)
335{
336 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
Jon Hunter44af7922015-10-09 15:45:55 +0100337 struct spi_device *spi = to_spi_device(dev);
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300338 int ret;
David Brownellb8852442006-01-08 13:34:23 -0800339
Sylwester Nawrocki86be4082014-06-18 17:29:32 +0200340 ret = of_clk_set_defaults(dev->of_node, false);
341 if (ret)
342 return ret;
343
Jon Hunter44af7922015-10-09 15:45:55 +0100344 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
Ulf Hansson676e7c22014-09-19 20:27:41 +0200352 ret = dev_pm_domain_attach(dev, true);
353 if (ret != -EPROBE_DEFER) {
Jon Hunter44af7922015-10-09 15:45:55 +0100354 ret = sdrv->probe(spi);
Ulf Hansson676e7c22014-09-19 20:27:41 +0200355 if (ret)
356 dev_pm_domain_detach(dev, true);
357 }
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300358
359 return ret;
David Brownellb8852442006-01-08 13:34:23 -0800360}
361
362static int spi_drv_remove(struct device *dev)
363{
364 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300365 int ret;
David Brownellb8852442006-01-08 13:34:23 -0800366
Jean Delvareaec35f42014-02-13 15:28:41 +0100367 ret = sdrv->remove(to_spi_device(dev));
Ulf Hansson676e7c22014-09-19 20:27:41 +0200368 dev_pm_domain_detach(dev, true);
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300369
370 return ret;
David Brownellb8852442006-01-08 13:34:23 -0800371}
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
David Brownell33e34dc2007-05-08 00:32:21 -0700380/**
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500381 * __spi_register_driver - register a SPI driver
Thierry Reding88c93212015-11-10 13:03:04 +0100382 * @owner: owner module of the driver to register
David Brownell33e34dc2007-05-08 00:32:21 -0700383 * @sdrv: the driver to register
384 * Context: can sleep
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +0200385 *
386 * Return: zero on success, else a negative error code.
David Brownell33e34dc2007-05-08 00:32:21 -0700387 */
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500388int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
David Brownellb8852442006-01-08 13:34:23 -0800389{
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500390 sdrv->driver.owner = owner;
David Brownellb8852442006-01-08 13:34:23 -0800391 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}
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500400EXPORT_SYMBOL_GPL(__spi_register_driver);
David Brownellb8852442006-01-08 13:34:23 -0800401
David Brownell8ae12a02006-01-08 13:34:19 -0800402/*-------------------------------------------------------------------------*/
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;
Feng Tang2b9603a2010-08-02 15:52:15 +0800412 struct spi_board_info board_info;
David Brownell8ae12a02006-01-08 13:34:19 -0800413};
414
415static LIST_HEAD(board_list);
Feng Tang2b9603a2010-08-02 15:52:15 +0800416static 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 */
Matthias Kaehlcke94040822007-07-17 04:04:16 -0700422static DEFINE_MUTEX(board_lock);
David Brownell8ae12a02006-01-08 13:34:19 -0800423
Grant Likelydc87c982008-05-15 16:50:22 -0600424/**
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 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +0200439 * Return: a pointer to the new device, or NULL.
Grant Likelydc87c982008-05-15 16:50:22 -0600440 */
441struct spi_device *spi_alloc_device(struct spi_master *master)
442{
443 struct spi_device *spi;
Grant Likelydc87c982008-05-15 16:50:22 -0600444
445 if (!spi_master_get(master))
446 return NULL;
447
Jingoo Han5fe5f052013-10-14 10:31:51 +0900448 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
Grant Likelydc87c982008-05-15 16:50:22 -0600449 if (!spi) {
Grant Likelydc87c982008-05-15 16:50:22 -0600450 spi_master_put(master);
451 return NULL;
452 }
453
454 spi->master = master;
Laurent Pinchart178db7d2011-12-12 01:15:06 +0100455 spi->dev.parent = &master->dev;
Grant Likelydc87c982008-05-15 16:50:22 -0600456 spi->dev.bus = &spi_bus_type;
457 spi->dev.release = spidev_release;
Andreas Larsson446411e2013-02-13 14:20:25 +0100458 spi->cs_gpio = -ENOENT;
Martin Sperleca2ebc2015-06-22 13:00:36 +0000459
460 spin_lock_init(&spi->statistics.lock);
461
Grant Likelydc87c982008-05-15 16:50:22 -0600462 device_initialize(&spi->dev);
463 return spi;
464}
465EXPORT_SYMBOL_GPL(spi_alloc_device);
466
Jarkko Nikulae13ac472013-11-14 14:03:53 +0200467static 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
Mika Westerbergb6fb8d32014-01-09 15:23:55 +0200480static 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
Grant Likelydc87c982008-05-15 16:50:22 -0600491/**
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 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +0200498 * Return: 0 on success; negative errno on failure
Grant Likelydc87c982008-05-15 16:50:22 -0600499 */
500int spi_add_device(struct spi_device *spi)
501{
David Brownelle48880e2008-08-15 00:40:44 -0700502 static DEFINE_MUTEX(spi_add_lock);
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100503 struct spi_master *master = spi->master;
504 struct device *dev = master->dev.parent;
Grant Likelydc87c982008-05-15 16:50:22 -0600505 int status;
506
507 /* Chipselects are numbered 0..max; validate. */
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100508 if (spi->chip_select >= master->num_chipselect) {
Grant Likelydc87c982008-05-15 16:50:22 -0600509 dev_err(dev, "cs%d >= max %d\n",
510 spi->chip_select,
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100511 master->num_chipselect);
Grant Likelydc87c982008-05-15 16:50:22 -0600512 return -EINVAL;
513 }
514
515 /* Set the bus ID string */
Jarkko Nikulae13ac472013-11-14 14:03:53 +0200516 spi_dev_set_name(spi);
David Brownelle48880e2008-08-15 00:40:44 -0700517
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
Mika Westerbergb6fb8d32014-01-09 15:23:55 +0200524 status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
525 if (status) {
David Brownelle48880e2008-08-15 00:40:44 -0700526 dev_err(dev, "chipselect %d already in use\n",
527 spi->chip_select);
David Brownelle48880e2008-08-15 00:40:44 -0700528 goto done;
529 }
530
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100531 if (master->cs_gpios)
532 spi->cs_gpio = master->cs_gpios[spi->chip_select];
533
David Brownelle48880e2008-08-15 00:40:44 -0700534 /* 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 */
David Brownell7d077192009-06-17 16:26:03 -0700538 status = spi_setup(spi);
Grant Likelydc87c982008-05-15 16:50:22 -0600539 if (status < 0) {
Linus Walleijeb288a12010-10-21 21:06:44 +0200540 dev_err(dev, "can't setup %s, status %d\n",
541 dev_name(&spi->dev), status);
David Brownelle48880e2008-08-15 00:40:44 -0700542 goto done;
Grant Likelydc87c982008-05-15 16:50:22 -0600543 }
544
David Brownelle48880e2008-08-15 00:40:44 -0700545 /* Device may be bound to an active driver when this returns */
Grant Likelydc87c982008-05-15 16:50:22 -0600546 status = device_add(&spi->dev);
David Brownelle48880e2008-08-15 00:40:44 -0700547 if (status < 0)
Linus Walleijeb288a12010-10-21 21:06:44 +0200548 dev_err(dev, "can't add %s, status %d\n",
549 dev_name(&spi->dev), status);
David Brownelle48880e2008-08-15 00:40:44 -0700550 else
Kay Sievers35f74fc2009-01-06 10:44:37 -0800551 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
Grant Likelydc87c982008-05-15 16:50:22 -0600552
David Brownelle48880e2008-08-15 00:40:44 -0700553done:
554 mutex_unlock(&spi_add_lock);
555 return status;
Grant Likelydc87c982008-05-15 16:50:22 -0600556}
557EXPORT_SYMBOL_GPL(spi_add_device);
David Brownell8ae12a02006-01-08 13:34:19 -0800558
David Brownell33e34dc2007-05-08 00:32:21 -0700559/**
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
David Brownell8ae12a02006-01-08 13:34:19 -0800566 * 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).
David Brownell082c8cb2007-07-31 00:39:45 -0700570 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +0200571 * Return: the new device, or NULL.
David Brownell8ae12a02006-01-08 13:34:19 -0800572 */
Adrian Bunke9d5a462007-03-26 21:32:23 -0800573struct spi_device *spi_new_device(struct spi_master *master,
574 struct spi_board_info *chip)
David Brownell8ae12a02006-01-08 13:34:19 -0800575{
576 struct spi_device *proxy;
David Brownell8ae12a02006-01-08 13:34:19 -0800577 int status;
578
David Brownell082c8cb2007-07-31 00:39:45 -0700579 /* 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
Grant Likelydc87c982008-05-15 16:50:22 -0600586 proxy = spi_alloc_device(master);
587 if (!proxy)
David Brownell8ae12a02006-01-08 13:34:19 -0800588 return NULL;
589
Grant Likely102eb972008-07-23 21:29:55 -0700590 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
591
David Brownell8ae12a02006-01-08 13:34:19 -0800592 proxy->chip_select = chip->chip_select;
593 proxy->max_speed_hz = chip->max_speed_hz;
David Brownell980a01c2006-06-28 07:47:15 -0700594 proxy->mode = chip->mode;
David Brownell8ae12a02006-01-08 13:34:19 -0800595 proxy->irq = chip->irq;
Grant Likely102eb972008-07-23 21:29:55 -0700596 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
David Brownell8ae12a02006-01-08 13:34:19 -0800597 proxy->dev.platform_data = (void *) chip->platform_data;
598 proxy->controller_data = chip->controller_data;
599 proxy->controller_state = NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800600
Grant Likelydc87c982008-05-15 16:50:22 -0600601 status = spi_add_device(proxy);
David Brownell8ae12a02006-01-08 13:34:19 -0800602 if (status < 0) {
Grant Likelydc87c982008-05-15 16:50:22 -0600603 spi_dev_put(proxy);
604 return NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800605 }
606
David Brownell8ae12a02006-01-08 13:34:19 -0800607 return proxy;
608}
609EXPORT_SYMBOL_GPL(spi_new_device);
610
Geert Uytterhoeven3b1884c2015-11-30 15:28:06 +0100611/**
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{
Geert Uytterhoevenbd6c1642015-11-30 15:28:07 +0100620 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);
Geert Uytterhoeven3b1884c2015-11-30 15:28:06 +0100626}
627EXPORT_SYMBOL_GPL(spi_unregister_device);
628
Feng Tang2b9603a2010-08-02 15:52:15 +0800629static 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
David Brownell33e34dc2007-05-08 00:32:21 -0700643/**
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 *
David Brownell8ae12a02006-01-08 13:34:19 -0800649 * 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.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +0200661 *
662 * Return: zero on success, else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -0800663 */
Grant Likelyfd4a3192012-12-07 16:57:14 +0000664int spi_register_board_info(struct spi_board_info const *info, unsigned n)
David Brownell8ae12a02006-01-08 13:34:19 -0800665{
Feng Tang2b9603a2010-08-02 15:52:15 +0800666 struct boardinfo *bi;
667 int i;
David Brownell8ae12a02006-01-08 13:34:19 -0800668
Xiubo Lic7908a32014-09-24 14:30:29 +0800669 if (!n)
670 return -EINVAL;
671
Feng Tang2b9603a2010-08-02 15:52:15 +0800672 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
David Brownell8ae12a02006-01-08 13:34:19 -0800673 if (!bi)
674 return -ENOMEM;
David Brownell8ae12a02006-01-08 13:34:19 -0800675
Feng Tang2b9603a2010-08-02 15:52:15 +0800676 for (i = 0; i < n; i++, bi++, info++) {
677 struct spi_master *master;
David Brownell8ae12a02006-01-08 13:34:19 -0800678
Feng Tang2b9603a2010-08-02 15:52:15 +0800679 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);
David Brownell8ae12a02006-01-08 13:34:19 -0800685 }
Feng Tang2b9603a2010-08-02 15:52:15 +0800686
687 return 0;
David Brownell8ae12a02006-01-08 13:34:19 -0800688}
689
690/*-------------------------------------------------------------------------*/
691
Mark Brownb1589352013-10-05 11:50:40 +0100692static void spi_set_cs(struct spi_device *spi, bool enable)
693{
694 if (spi->mode & SPI_CS_HIGH)
695 enable = !enable;
696
Andy Shevchenko243f07b2015-10-20 12:28:29 +0300697 if (gpio_is_valid(spi->cs_gpio))
Mark Brownb1589352013-10-05 11:50:40 +0100698 gpio_set_value(spi->cs_gpio, !enable);
699 else if (spi->master->set_cs)
700 spi->master->set_cs(spi, !enable);
701}
702
Geert Uytterhoeven2de440f2014-05-02 06:29:34 +0200703#ifdef CONFIG_HAS_DMA
Mark Brown6ad45a22014-02-02 13:47:47 +0000704static 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);
Andy Shevchenkodf88e912016-03-09 11:20:00 +0200709 unsigned int max_seg_size = dma_get_max_seg_size(dev);
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500710 int desc_len;
711 int sgs;
Mark Brown6ad45a22014-02-02 13:47:47 +0000712 struct page *vm_page;
713 void *sg_buf;
714 size_t min;
715 int i, ret;
716
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500717 if (vmalloced_buf) {
Andy Shevchenkodf88e912016-03-09 11:20:00 +0200718 desc_len = min_t(int, max_seg_size, PAGE_SIZE);
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500719 sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
Vignesh R0569a882016-04-25 15:14:00 +0530720 } else if (virt_addr_valid(buf)) {
Andy Shevchenkodf88e912016-03-09 11:20:00 +0200721 desc_len = min_t(int, max_seg_size, master->max_dma_len);
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500722 sgs = DIV_ROUND_UP(len, desc_len);
Vignesh R0569a882016-04-25 15:14:00 +0530723 } else {
724 return -EINVAL;
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500725 }
726
Mark Brown6ad45a22014-02-02 13:47:47 +0000727 ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
728 if (ret != 0)
729 return ret;
730
731 for (i = 0; i < sgs; i++) {
Mark Brown6ad45a22014-02-02 13:47:47 +0000732
733 if (vmalloced_buf) {
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500734 min = min_t(size_t,
735 len, desc_len - offset_in_page(buf));
Mark Brown6ad45a22014-02-02 13:47:47 +0000736 vm_page = vmalloc_to_page(buf);
737 if (!vm_page) {
738 sg_free_table(sgt);
739 return -ENOMEM;
740 }
Charles Keepaxc1aefbd2014-11-17 09:14:31 +0000741 sg_set_page(&sgt->sgl[i], vm_page,
742 min, offset_in_page(buf));
Mark Brown6ad45a22014-02-02 13:47:47 +0000743 } else {
Andrew Gabbasov65598c12015-06-30 10:48:37 -0500744 min = min_t(size_t, len, desc_len);
Mark Brown6ad45a22014-02-02 13:47:47 +0000745 sg_buf = buf;
Charles Keepaxc1aefbd2014-11-17 09:14:31 +0000746 sg_set_buf(&sgt->sgl[i], sg_buf, min);
Mark Brown6ad45a22014-02-02 13:47:47 +0000747 }
748
Mark Brown6ad45a22014-02-02 13:47:47 +0000749 buf += min;
750 len -= min;
751 }
752
753 ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
Geert Uytterhoeven89e4b662014-07-10 15:29:32 +0200754 if (!ret)
755 ret = -ENOMEM;
Mark Brown6ad45a22014-02-02 13:47:47 +0000756 if (ret < 0) {
757 sg_free_table(sgt);
758 return ret;
759 }
760
761 sgt->nents = ret;
762
763 return 0;
764}
765
766static void spi_unmap_buf(struct spi_master *master, struct device *dev,
767 struct sg_table *sgt, enum dma_data_direction dir)
768{
769 if (sgt->orig_nents) {
770 dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
771 sg_free_table(sgt);
772 }
773}
774
Geert Uytterhoeven2de440f2014-05-02 06:29:34 +0200775static int __spi_map_msg(struct spi_master *master, struct spi_message *msg)
Mark Brown99adef32014-01-16 12:22:43 +0000776{
Mark Brown99adef32014-01-16 12:22:43 +0000777 struct device *tx_dev, *rx_dev;
778 struct spi_transfer *xfer;
Mark Brown6ad45a22014-02-02 13:47:47 +0000779 int ret;
Mark Brown3a2eba92014-01-28 20:17:03 +0000780
Mark Brown6ad45a22014-02-02 13:47:47 +0000781 if (!master->can_dma)
Mark Brown99adef32014-01-16 12:22:43 +0000782 return 0;
783
Leilk Liuc37f45b2015-07-23 17:10:40 +0800784 if (master->dma_tx)
785 tx_dev = master->dma_tx->device->dev;
786 else
787 tx_dev = &master->dev;
788
789 if (master->dma_rx)
790 rx_dev = master->dma_rx->device->dev;
791 else
792 rx_dev = &master->dev;
Mark Brown99adef32014-01-16 12:22:43 +0000793
794 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
795 if (!master->can_dma(master, msg->spi, xfer))
796 continue;
797
798 if (xfer->tx_buf != NULL) {
Mark Brown6ad45a22014-02-02 13:47:47 +0000799 ret = spi_map_buf(master, tx_dev, &xfer->tx_sg,
800 (void *)xfer->tx_buf, xfer->len,
801 DMA_TO_DEVICE);
802 if (ret != 0)
803 return ret;
Mark Brown99adef32014-01-16 12:22:43 +0000804 }
805
806 if (xfer->rx_buf != NULL) {
Mark Brown6ad45a22014-02-02 13:47:47 +0000807 ret = spi_map_buf(master, rx_dev, &xfer->rx_sg,
808 xfer->rx_buf, xfer->len,
809 DMA_FROM_DEVICE);
810 if (ret != 0) {
811 spi_unmap_buf(master, tx_dev, &xfer->tx_sg,
812 DMA_TO_DEVICE);
813 return ret;
Mark Brown99adef32014-01-16 12:22:43 +0000814 }
815 }
816 }
817
818 master->cur_msg_mapped = true;
819
820 return 0;
821}
822
Martin Sperl4b786452015-05-25 10:13:10 +0000823static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
Mark Brown99adef32014-01-16 12:22:43 +0000824{
825 struct spi_transfer *xfer;
826 struct device *tx_dev, *rx_dev;
827
Mark Brown6ad45a22014-02-02 13:47:47 +0000828 if (!master->cur_msg_mapped || !master->can_dma)
Mark Brown99adef32014-01-16 12:22:43 +0000829 return 0;
830
Leilk Liuc37f45b2015-07-23 17:10:40 +0800831 if (master->dma_tx)
832 tx_dev = master->dma_tx->device->dev;
833 else
834 tx_dev = &master->dev;
835
836 if (master->dma_rx)
837 rx_dev = master->dma_rx->device->dev;
838 else
839 rx_dev = &master->dev;
Mark Brown99adef32014-01-16 12:22:43 +0000840
841 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
842 if (!master->can_dma(master, msg->spi, xfer))
843 continue;
844
Mark Brown6ad45a22014-02-02 13:47:47 +0000845 spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
846 spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
Mark Brown99adef32014-01-16 12:22:43 +0000847 }
848
849 return 0;
850}
Geert Uytterhoeven2de440f2014-05-02 06:29:34 +0200851#else /* !CONFIG_HAS_DMA */
852static inline int __spi_map_msg(struct spi_master *master,
853 struct spi_message *msg)
854{
855 return 0;
856}
857
Martin Sperl4b786452015-05-25 10:13:10 +0000858static inline int __spi_unmap_msg(struct spi_master *master,
859 struct spi_message *msg)
Geert Uytterhoeven2de440f2014-05-02 06:29:34 +0200860{
861 return 0;
862}
863#endif /* !CONFIG_HAS_DMA */
864
Martin Sperl4b786452015-05-25 10:13:10 +0000865static inline int spi_unmap_msg(struct spi_master *master,
866 struct spi_message *msg)
867{
868 struct spi_transfer *xfer;
869
870 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
871 /*
872 * Restore the original value of tx_buf or rx_buf if they are
873 * NULL.
874 */
875 if (xfer->tx_buf == master->dummy_tx)
876 xfer->tx_buf = NULL;
877 if (xfer->rx_buf == master->dummy_rx)
878 xfer->rx_buf = NULL;
879 }
880
881 return __spi_unmap_msg(master, msg);
882}
883
Geert Uytterhoeven2de440f2014-05-02 06:29:34 +0200884static int spi_map_msg(struct spi_master *master, struct spi_message *msg)
885{
886 struct spi_transfer *xfer;
887 void *tmp;
888 unsigned int max_tx, max_rx;
889
890 if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) {
891 max_tx = 0;
892 max_rx = 0;
893
894 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
895 if ((master->flags & SPI_MASTER_MUST_TX) &&
896 !xfer->tx_buf)
897 max_tx = max(xfer->len, max_tx);
898 if ((master->flags & SPI_MASTER_MUST_RX) &&
899 !xfer->rx_buf)
900 max_rx = max(xfer->len, max_rx);
901 }
902
903 if (max_tx) {
904 tmp = krealloc(master->dummy_tx, max_tx,
905 GFP_KERNEL | GFP_DMA);
906 if (!tmp)
907 return -ENOMEM;
908 master->dummy_tx = tmp;
909 memset(tmp, 0, max_tx);
910 }
911
912 if (max_rx) {
913 tmp = krealloc(master->dummy_rx, max_rx,
914 GFP_KERNEL | GFP_DMA);
915 if (!tmp)
916 return -ENOMEM;
917 master->dummy_rx = tmp;
918 }
919
920 if (max_tx || max_rx) {
921 list_for_each_entry(xfer, &msg->transfers,
922 transfer_list) {
923 if (!xfer->tx_buf)
924 xfer->tx_buf = master->dummy_tx;
925 if (!xfer->rx_buf)
926 xfer->rx_buf = master->dummy_rx;
927 }
928 }
929 }
930
931 return __spi_map_msg(master, msg);
932}
Mark Brown99adef32014-01-16 12:22:43 +0000933
Mark Brownb1589352013-10-05 11:50:40 +0100934/*
935 * spi_transfer_one_message - Default implementation of transfer_one_message()
936 *
937 * This is a standard implementation of transfer_one_message() for
Moritz Fischer8ba811a2016-05-03 11:59:30 -0700938 * drivers which implement a transfer_one() operation. It provides
Mark Brownb1589352013-10-05 11:50:40 +0100939 * standard handling of delays and chip select management.
940 */
941static int spi_transfer_one_message(struct spi_master *master,
942 struct spi_message *msg)
943{
944 struct spi_transfer *xfer;
Mark Brownb1589352013-10-05 11:50:40 +0100945 bool keep_cs = false;
946 int ret = 0;
Nicholas Mc Guire682a71b2015-02-02 03:30:32 -0500947 unsigned long ms = 1;
Martin Sperleca2ebc2015-06-22 13:00:36 +0000948 struct spi_statistics *statm = &master->statistics;
949 struct spi_statistics *stats = &msg->spi->statistics;
Mark Brownb1589352013-10-05 11:50:40 +0100950
951 spi_set_cs(msg->spi, true);
952
Martin Sperleca2ebc2015-06-22 13:00:36 +0000953 SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
954 SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
955
Mark Brownb1589352013-10-05 11:50:40 +0100956 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
957 trace_spi_transfer_start(msg, xfer);
958
Martin Sperleca2ebc2015-06-22 13:00:36 +0000959 spi_statistics_add_transfer_stats(statm, xfer, master);
960 spi_statistics_add_transfer_stats(stats, xfer, master);
961
Mark Brown38ec10f2014-08-16 16:27:41 +0100962 if (xfer->tx_buf || xfer->rx_buf) {
963 reinit_completion(&master->xfer_completion);
Mark Brownb1589352013-10-05 11:50:40 +0100964
Mark Brown38ec10f2014-08-16 16:27:41 +0100965 ret = master->transfer_one(master, msg->spi, xfer);
966 if (ret < 0) {
Martin Sperleca2ebc2015-06-22 13:00:36 +0000967 SPI_STATISTICS_INCREMENT_FIELD(statm,
968 errors);
969 SPI_STATISTICS_INCREMENT_FIELD(stats,
970 errors);
Mark Brown38ec10f2014-08-16 16:27:41 +0100971 dev_err(&msg->spi->dev,
972 "SPI transfer failed: %d\n", ret);
973 goto out;
974 }
Mark Brownb1589352013-10-05 11:50:40 +0100975
Mark Brown38ec10f2014-08-16 16:27:41 +0100976 if (ret > 0) {
977 ret = 0;
978 ms = xfer->len * 8 * 1000 / xfer->speed_hz;
979 ms += ms + 100; /* some tolerance */
Mark Brown16a0ce42014-01-30 22:16:41 +0000980
Mark Brown38ec10f2014-08-16 16:27:41 +0100981 ms = wait_for_completion_timeout(&master->xfer_completion,
982 msecs_to_jiffies(ms));
983 }
Mark Brown16a0ce42014-01-30 22:16:41 +0000984
Mark Brown38ec10f2014-08-16 16:27:41 +0100985 if (ms == 0) {
Martin Sperleca2ebc2015-06-22 13:00:36 +0000986 SPI_STATISTICS_INCREMENT_FIELD(statm,
987 timedout);
988 SPI_STATISTICS_INCREMENT_FIELD(stats,
989 timedout);
Mark Brown38ec10f2014-08-16 16:27:41 +0100990 dev_err(&msg->spi->dev,
991 "SPI transfer timed out\n");
992 msg->status = -ETIMEDOUT;
993 }
994 } else {
995 if (xfer->len)
996 dev_err(&msg->spi->dev,
997 "Bufferless transfer has length %u\n",
998 xfer->len);
Axel Lin13a42792014-01-18 22:05:22 +0800999 }
Mark Brownb1589352013-10-05 11:50:40 +01001000
1001 trace_spi_transfer_stop(msg, xfer);
1002
1003 if (msg->status != -EINPROGRESS)
1004 goto out;
1005
1006 if (xfer->delay_usecs)
1007 udelay(xfer->delay_usecs);
1008
1009 if (xfer->cs_change) {
1010 if (list_is_last(&xfer->transfer_list,
1011 &msg->transfers)) {
1012 keep_cs = true;
1013 } else {
Mark Brown0b73aa62014-03-29 23:48:07 +00001014 spi_set_cs(msg->spi, false);
1015 udelay(10);
1016 spi_set_cs(msg->spi, true);
Mark Brownb1589352013-10-05 11:50:40 +01001017 }
1018 }
1019
1020 msg->actual_length += xfer->len;
1021 }
1022
1023out:
1024 if (ret != 0 || !keep_cs)
1025 spi_set_cs(msg->spi, false);
1026
1027 if (msg->status == -EINPROGRESS)
1028 msg->status = ret;
1029
Geert Uytterhoevenff61eb42015-04-07 20:39:19 +02001030 if (msg->status && master->handle_err)
Andy Shevchenkob716c4f2015-02-27 17:34:15 +02001031 master->handle_err(master, msg);
1032
Martin Sperld780c372015-12-14 15:20:18 +00001033 spi_res_release(master, msg);
1034
Mark Brownb1589352013-10-05 11:50:40 +01001035 spi_finalize_current_message(master);
1036
1037 return ret;
1038}
1039
1040/**
1041 * spi_finalize_current_transfer - report completion of a transfer
Thierry Reding2c675682014-08-08 13:02:36 +02001042 * @master: the master reporting completion
Mark Brownb1589352013-10-05 11:50:40 +01001043 *
1044 * Called by SPI drivers using the core transfer_one_message()
1045 * implementation to notify it that the current interrupt driven
Geert Uytterhoeven9e8f4882014-01-21 16:10:05 +01001046 * transfer has finished and the next one may be scheduled.
Mark Brownb1589352013-10-05 11:50:40 +01001047 */
1048void spi_finalize_current_transfer(struct spi_master *master)
1049{
1050 complete(&master->xfer_completion);
1051}
1052EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
1053
Linus Walleijffbbdd212012-02-22 10:05:38 +01001054/**
Mark Brownfc9e0f72014-12-10 13:46:33 +00001055 * __spi_pump_messages - function which processes spi message queue
1056 * @master: master to process queue for
1057 * @in_kthread: true if we are in the context of the message pump thread
Jon Hunter49023d22016-03-08 12:28:20 +00001058 * @bus_locked: true if the bus mutex is held when calling this function
Linus Walleijffbbdd212012-02-22 10:05:38 +01001059 *
1060 * This function checks if there is any spi message in the queue that
1061 * needs processing and if so call out to the driver to initialize hardware
1062 * and transfer each message.
1063 *
Mark Brown0461a412014-12-09 21:38:05 +00001064 * Note that it is called both from the kthread itself and also from
1065 * inside spi_sync(); the queue extraction handling at the top of the
1066 * function should deal with this safely.
Linus Walleijffbbdd212012-02-22 10:05:38 +01001067 */
Jon Hunter49023d22016-03-08 12:28:20 +00001068static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
1069 bool bus_locked)
Linus Walleijffbbdd212012-02-22 10:05:38 +01001070{
Linus Walleijffbbdd212012-02-22 10:05:38 +01001071 unsigned long flags;
1072 bool was_busy = false;
1073 int ret;
1074
Mark Brown983aee52014-12-09 19:46:56 +00001075 /* Lock queue */
Linus Walleijffbbdd212012-02-22 10:05:38 +01001076 spin_lock_irqsave(&master->queue_lock, flags);
Mark Brown983aee52014-12-09 19:46:56 +00001077
1078 /* Make sure we are not already running a message */
1079 if (master->cur_msg) {
1080 spin_unlock_irqrestore(&master->queue_lock, flags);
1081 return;
1082 }
1083
Mark Brown0461a412014-12-09 21:38:05 +00001084 /* If another context is idling the device then defer */
1085 if (master->idling) {
1086 queue_kthread_work(&master->kworker, &master->pump_messages);
1087 spin_unlock_irqrestore(&master->queue_lock, flags);
1088 return;
1089 }
1090
Mark Brown983aee52014-12-09 19:46:56 +00001091 /* Check if the queue is idle */
Linus Walleijffbbdd212012-02-22 10:05:38 +01001092 if (list_empty(&master->queue) || !master->running) {
Bryan Freedb0b36b82013-03-13 11:17:40 -07001093 if (!master->busy) {
1094 spin_unlock_irqrestore(&master->queue_lock, flags);
1095 return;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001096 }
Mark Brownfc9e0f72014-12-10 13:46:33 +00001097
1098 /* Only do teardown in the thread */
1099 if (!in_kthread) {
1100 queue_kthread_work(&master->kworker,
1101 &master->pump_messages);
1102 spin_unlock_irqrestore(&master->queue_lock, flags);
1103 return;
1104 }
1105
Linus Walleijffbbdd212012-02-22 10:05:38 +01001106 master->busy = false;
Mark Brown0461a412014-12-09 21:38:05 +00001107 master->idling = true;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001108 spin_unlock_irqrestore(&master->queue_lock, flags);
Mark Brown0461a412014-12-09 21:38:05 +00001109
Mark Brown3a2eba92014-01-28 20:17:03 +00001110 kfree(master->dummy_rx);
1111 master->dummy_rx = NULL;
1112 kfree(master->dummy_tx);
1113 master->dummy_tx = NULL;
Bryan Freedb0b36b82013-03-13 11:17:40 -07001114 if (master->unprepare_transfer_hardware &&
1115 master->unprepare_transfer_hardware(master))
1116 dev_err(&master->dev,
1117 "failed to unprepare transfer hardware\n");
Mark Brown49834de2013-07-28 14:47:02 +01001118 if (master->auto_runtime_pm) {
1119 pm_runtime_mark_last_busy(master->dev.parent);
1120 pm_runtime_put_autosuspend(master->dev.parent);
1121 }
Mark Brown56ec1972013-10-07 19:33:53 +01001122 trace_spi_master_idle(master);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001123
Mark Brown0461a412014-12-09 21:38:05 +00001124 spin_lock_irqsave(&master->queue_lock, flags);
1125 master->idling = false;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001126 spin_unlock_irqrestore(&master->queue_lock, flags);
1127 return;
1128 }
Linus Walleijffbbdd212012-02-22 10:05:38 +01001129
Linus Walleijffbbdd212012-02-22 10:05:38 +01001130 /* Extract head of queue */
1131 master->cur_msg =
Axel Lina89e2d22014-01-09 16:03:58 +08001132 list_first_entry(&master->queue, struct spi_message, queue);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001133
1134 list_del_init(&master->cur_msg->queue);
1135 if (master->busy)
1136 was_busy = true;
1137 else
1138 master->busy = true;
1139 spin_unlock_irqrestore(&master->queue_lock, flags);
1140
Mark Brown49834de2013-07-28 14:47:02 +01001141 if (!was_busy && master->auto_runtime_pm) {
1142 ret = pm_runtime_get_sync(master->dev.parent);
1143 if (ret < 0) {
1144 dev_err(&master->dev, "Failed to power device: %d\n",
1145 ret);
1146 return;
1147 }
1148 }
1149
Mark Brown56ec1972013-10-07 19:33:53 +01001150 if (!was_busy)
1151 trace_spi_master_busy(master);
1152
Shubhrajyoti D7dfd2bd2012-05-10 19:20:41 +05301153 if (!was_busy && master->prepare_transfer_hardware) {
Linus Walleijffbbdd212012-02-22 10:05:38 +01001154 ret = master->prepare_transfer_hardware(master);
1155 if (ret) {
1156 dev_err(&master->dev,
1157 "failed to prepare transfer hardware\n");
Mark Brown49834de2013-07-28 14:47:02 +01001158
1159 if (master->auto_runtime_pm)
1160 pm_runtime_put(master->dev.parent);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001161 return;
1162 }
1163 }
1164
Jon Hunter49023d22016-03-08 12:28:20 +00001165 if (!bus_locked)
1166 mutex_lock(&master->bus_lock_mutex);
1167
Mark Brown56ec1972013-10-07 19:33:53 +01001168 trace_spi_message_start(master->cur_msg);
1169
Mark Brown2841a5f2013-10-05 00:23:12 +01001170 if (master->prepare_message) {
1171 ret = master->prepare_message(master, master->cur_msg);
1172 if (ret) {
1173 dev_err(&master->dev,
1174 "failed to prepare message: %d\n", ret);
1175 master->cur_msg->status = ret;
1176 spi_finalize_current_message(master);
Jon Hunter49023d22016-03-08 12:28:20 +00001177 goto out;
Mark Brown2841a5f2013-10-05 00:23:12 +01001178 }
1179 master->cur_msg_prepared = true;
1180 }
1181
Mark Brown99adef32014-01-16 12:22:43 +00001182 ret = spi_map_msg(master, master->cur_msg);
1183 if (ret) {
1184 master->cur_msg->status = ret;
1185 spi_finalize_current_message(master);
Jon Hunter49023d22016-03-08 12:28:20 +00001186 goto out;
Mark Brown99adef32014-01-16 12:22:43 +00001187 }
1188
Linus Walleijffbbdd212012-02-22 10:05:38 +01001189 ret = master->transfer_one_message(master, master->cur_msg);
1190 if (ret) {
1191 dev_err(&master->dev,
Geert Uytterhoeven1f802f82014-01-28 10:33:03 +01001192 "failed to transfer one message from queue\n");
Jon Hunter49023d22016-03-08 12:28:20 +00001193 goto out;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001194 }
Jon Hunter49023d22016-03-08 12:28:20 +00001195
1196out:
1197 if (!bus_locked)
1198 mutex_unlock(&master->bus_lock_mutex);
Mark Brown62826972016-02-15 18:28:02 +00001199
1200 /* Prod the scheduler in case transfer_one() was busy waiting */
Jon Hunter49023d22016-03-08 12:28:20 +00001201 if (!ret)
1202 cond_resched();
Linus Walleijffbbdd212012-02-22 10:05:38 +01001203}
1204
Mark Brownfc9e0f72014-12-10 13:46:33 +00001205/**
1206 * spi_pump_messages - kthread work function which processes spi message queue
1207 * @work: pointer to kthread work struct contained in the master struct
1208 */
1209static void spi_pump_messages(struct kthread_work *work)
1210{
1211 struct spi_master *master =
1212 container_of(work, struct spi_master, pump_messages);
1213
Heiko Stübner24c8cd12016-03-18 11:15:11 +01001214 __spi_pump_messages(master, true, master->bus_lock_flag);
Mark Brownfc9e0f72014-12-10 13:46:33 +00001215}
1216
Linus Walleijffbbdd212012-02-22 10:05:38 +01001217static int spi_init_queue(struct spi_master *master)
1218{
1219 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
1220
Linus Walleijffbbdd212012-02-22 10:05:38 +01001221 master->running = false;
1222 master->busy = false;
1223
1224 init_kthread_worker(&master->kworker);
1225 master->kworker_task = kthread_run(kthread_worker_fn,
Kees Cookf1701682013-07-03 15:04:58 -07001226 &master->kworker, "%s",
Linus Walleijffbbdd212012-02-22 10:05:38 +01001227 dev_name(&master->dev));
1228 if (IS_ERR(master->kworker_task)) {
1229 dev_err(&master->dev, "failed to create message pump task\n");
Jarkko Nikula98a8f5a2014-12-04 11:02:25 +02001230 return PTR_ERR(master->kworker_task);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001231 }
1232 init_kthread_work(&master->pump_messages, spi_pump_messages);
1233
1234 /*
1235 * Master config will indicate if this controller should run the
1236 * message pump with high (realtime) priority to reduce the transfer
1237 * latency on the bus by minimising the delay between a transfer
1238 * request and the scheduling of the message pump thread. Without this
1239 * setting the message pump thread will remain at default priority.
1240 */
1241 if (master->rt) {
1242 dev_info(&master->dev,
1243 "will run message pump with realtime priority\n");
1244 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
1245 }
1246
1247 return 0;
1248}
1249
1250/**
1251 * spi_get_next_queued_message() - called by driver to check for queued
1252 * messages
1253 * @master: the master to check for queued messages
1254 *
1255 * If there are more messages in the queue, the next message is returned from
1256 * this call.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001257 *
1258 * Return: the next message in the queue, else NULL if the queue is empty.
Linus Walleijffbbdd212012-02-22 10:05:38 +01001259 */
1260struct spi_message *spi_get_next_queued_message(struct spi_master *master)
1261{
1262 struct spi_message *next;
1263 unsigned long flags;
1264
1265 /* get a pointer to the next message, if any */
1266 spin_lock_irqsave(&master->queue_lock, flags);
Axel Lin1cfd97f2014-01-02 15:16:40 +08001267 next = list_first_entry_or_null(&master->queue, struct spi_message,
1268 queue);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001269 spin_unlock_irqrestore(&master->queue_lock, flags);
1270
1271 return next;
1272}
1273EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
1274
1275/**
1276 * spi_finalize_current_message() - the current message is complete
1277 * @master: the master to return the message to
1278 *
1279 * Called by the driver to notify the core that the message in the front of the
1280 * queue is complete and can be removed from the queue.
1281 */
1282void spi_finalize_current_message(struct spi_master *master)
1283{
1284 struct spi_message *mesg;
1285 unsigned long flags;
Mark Brown2841a5f2013-10-05 00:23:12 +01001286 int ret;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001287
1288 spin_lock_irqsave(&master->queue_lock, flags);
1289 mesg = master->cur_msg;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001290 spin_unlock_irqrestore(&master->queue_lock, flags);
1291
Mark Brown99adef32014-01-16 12:22:43 +00001292 spi_unmap_msg(master, mesg);
1293
Mark Brown2841a5f2013-10-05 00:23:12 +01001294 if (master->cur_msg_prepared && master->unprepare_message) {
1295 ret = master->unprepare_message(master, mesg);
1296 if (ret) {
1297 dev_err(&master->dev,
1298 "failed to unprepare message: %d\n", ret);
1299 }
1300 }
Uwe Kleine-König391949b2015-03-18 11:27:28 +01001301
Martin Sperl8e76ef82015-05-10 07:50:45 +00001302 spin_lock_irqsave(&master->queue_lock, flags);
1303 master->cur_msg = NULL;
Mark Brown2841a5f2013-10-05 00:23:12 +01001304 master->cur_msg_prepared = false;
Martin Sperl8e76ef82015-05-10 07:50:45 +00001305 queue_kthread_work(&master->kworker, &master->pump_messages);
1306 spin_unlock_irqrestore(&master->queue_lock, flags);
1307
1308 trace_spi_message_done(mesg);
Mark Brown2841a5f2013-10-05 00:23:12 +01001309
Linus Walleijffbbdd212012-02-22 10:05:38 +01001310 mesg->state = NULL;
1311 if (mesg->complete)
1312 mesg->complete(mesg->context);
1313}
1314EXPORT_SYMBOL_GPL(spi_finalize_current_message);
1315
1316static int spi_start_queue(struct spi_master *master)
1317{
1318 unsigned long flags;
1319
1320 spin_lock_irqsave(&master->queue_lock, flags);
1321
1322 if (master->running || master->busy) {
1323 spin_unlock_irqrestore(&master->queue_lock, flags);
1324 return -EBUSY;
1325 }
1326
1327 master->running = true;
1328 master->cur_msg = NULL;
1329 spin_unlock_irqrestore(&master->queue_lock, flags);
1330
1331 queue_kthread_work(&master->kworker, &master->pump_messages);
1332
1333 return 0;
1334}
1335
1336static int spi_stop_queue(struct spi_master *master)
1337{
1338 unsigned long flags;
1339 unsigned limit = 500;
1340 int ret = 0;
1341
1342 spin_lock_irqsave(&master->queue_lock, flags);
1343
1344 /*
1345 * This is a bit lame, but is optimized for the common execution path.
1346 * A wait_queue on the master->busy could be used, but then the common
1347 * execution path (pump_messages) would be required to call wake_up or
1348 * friends on every SPI message. Do this instead.
1349 */
1350 while ((!list_empty(&master->queue) || master->busy) && limit--) {
1351 spin_unlock_irqrestore(&master->queue_lock, flags);
Axel Linf97b26b2014-02-21 09:15:18 +08001352 usleep_range(10000, 11000);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001353 spin_lock_irqsave(&master->queue_lock, flags);
1354 }
1355
1356 if (!list_empty(&master->queue) || master->busy)
1357 ret = -EBUSY;
1358 else
1359 master->running = false;
1360
1361 spin_unlock_irqrestore(&master->queue_lock, flags);
1362
1363 if (ret) {
1364 dev_warn(&master->dev,
1365 "could not stop message queue\n");
1366 return ret;
1367 }
1368 return ret;
1369}
1370
1371static int spi_destroy_queue(struct spi_master *master)
1372{
1373 int ret;
1374
1375 ret = spi_stop_queue(master);
1376
1377 /*
1378 * flush_kthread_worker will block until all work is done.
1379 * If the reason that stop_queue timed out is that the work will never
1380 * finish, then it does no good to call flush/stop thread, so
1381 * return anyway.
1382 */
1383 if (ret) {
1384 dev_err(&master->dev, "problem destroying queue\n");
1385 return ret;
1386 }
1387
1388 flush_kthread_worker(&master->kworker);
1389 kthread_stop(master->kworker_task);
1390
1391 return 0;
1392}
1393
Mark Brown0461a412014-12-09 21:38:05 +00001394static int __spi_queued_transfer(struct spi_device *spi,
1395 struct spi_message *msg,
1396 bool need_pump)
Linus Walleijffbbdd212012-02-22 10:05:38 +01001397{
1398 struct spi_master *master = spi->master;
1399 unsigned long flags;
1400
1401 spin_lock_irqsave(&master->queue_lock, flags);
1402
1403 if (!master->running) {
1404 spin_unlock_irqrestore(&master->queue_lock, flags);
1405 return -ESHUTDOWN;
1406 }
1407 msg->actual_length = 0;
1408 msg->status = -EINPROGRESS;
1409
1410 list_add_tail(&msg->queue, &master->queue);
Mark Brown0461a412014-12-09 21:38:05 +00001411 if (!master->busy && need_pump)
Linus Walleijffbbdd212012-02-22 10:05:38 +01001412 queue_kthread_work(&master->kworker, &master->pump_messages);
1413
1414 spin_unlock_irqrestore(&master->queue_lock, flags);
1415 return 0;
1416}
1417
Mark Brown0461a412014-12-09 21:38:05 +00001418/**
1419 * spi_queued_transfer - transfer function for queued transfers
1420 * @spi: spi device which is requesting transfer
1421 * @msg: spi message which is to handled is queued to driver queue
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001422 *
1423 * Return: zero on success, else a negative error code.
Mark Brown0461a412014-12-09 21:38:05 +00001424 */
1425static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
1426{
1427 return __spi_queued_transfer(spi, msg, true);
1428}
1429
Linus Walleijffbbdd212012-02-22 10:05:38 +01001430static int spi_master_initialize_queue(struct spi_master *master)
1431{
1432 int ret;
1433
Linus Walleijffbbdd212012-02-22 10:05:38 +01001434 master->transfer = spi_queued_transfer;
Mark Brownb1589352013-10-05 11:50:40 +01001435 if (!master->transfer_one_message)
1436 master->transfer_one_message = spi_transfer_one_message;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001437
1438 /* Initialize and start queue */
1439 ret = spi_init_queue(master);
1440 if (ret) {
1441 dev_err(&master->dev, "problem initializing queue\n");
1442 goto err_init_queue;
1443 }
Mark Brownc3676d52014-05-01 10:47:52 -07001444 master->queued = true;
Linus Walleijffbbdd212012-02-22 10:05:38 +01001445 ret = spi_start_queue(master);
1446 if (ret) {
1447 dev_err(&master->dev, "problem starting queue\n");
1448 goto err_start_queue;
1449 }
1450
1451 return 0;
1452
1453err_start_queue:
Linus Walleijffbbdd212012-02-22 10:05:38 +01001454 spi_destroy_queue(master);
Mark Brownc3676d52014-05-01 10:47:52 -07001455err_init_queue:
Linus Walleijffbbdd212012-02-22 10:05:38 +01001456 return ret;
1457}
1458
1459/*-------------------------------------------------------------------------*/
1460
Andreas Larsson7cb94362012-12-04 15:09:38 +01001461#if defined(CONFIG_OF)
Pantelis Antoniouaff5e3f2014-10-29 10:40:37 +02001462static struct spi_device *
1463of_register_spi_device(struct spi_master *master, struct device_node *nc)
1464{
1465 struct spi_device *spi;
1466 int rc;
1467 u32 value;
1468
1469 /* Alloc an spi_device */
1470 spi = spi_alloc_device(master);
1471 if (!spi) {
1472 dev_err(&master->dev, "spi_device alloc error for %s\n",
1473 nc->full_name);
1474 rc = -ENOMEM;
1475 goto err_out;
1476 }
1477
1478 /* Select device driver */
1479 rc = of_modalias_node(nc, spi->modalias,
1480 sizeof(spi->modalias));
1481 if (rc < 0) {
1482 dev_err(&master->dev, "cannot find modalias for %s\n",
1483 nc->full_name);
1484 goto err_out;
1485 }
1486
1487 /* Device address */
1488 rc = of_property_read_u32(nc, "reg", &value);
1489 if (rc) {
1490 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1491 nc->full_name, rc);
1492 goto err_out;
1493 }
1494 spi->chip_select = value;
1495
1496 /* Mode (clock phase/polarity/etc.) */
1497 if (of_find_property(nc, "spi-cpha", NULL))
1498 spi->mode |= SPI_CPHA;
1499 if (of_find_property(nc, "spi-cpol", NULL))
1500 spi->mode |= SPI_CPOL;
1501 if (of_find_property(nc, "spi-cs-high", NULL))
1502 spi->mode |= SPI_CS_HIGH;
1503 if (of_find_property(nc, "spi-3wire", NULL))
1504 spi->mode |= SPI_3WIRE;
1505 if (of_find_property(nc, "spi-lsb-first", NULL))
1506 spi->mode |= SPI_LSB_FIRST;
1507
1508 /* Device DUAL/QUAD mode */
1509 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1510 switch (value) {
1511 case 1:
1512 break;
1513 case 2:
1514 spi->mode |= SPI_TX_DUAL;
1515 break;
1516 case 4:
1517 spi->mode |= SPI_TX_QUAD;
1518 break;
1519 default:
1520 dev_warn(&master->dev,
1521 "spi-tx-bus-width %d not supported\n",
1522 value);
1523 break;
1524 }
1525 }
1526
1527 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1528 switch (value) {
1529 case 1:
1530 break;
1531 case 2:
1532 spi->mode |= SPI_RX_DUAL;
1533 break;
1534 case 4:
1535 spi->mode |= SPI_RX_QUAD;
1536 break;
1537 default:
1538 dev_warn(&master->dev,
1539 "spi-rx-bus-width %d not supported\n",
1540 value);
1541 break;
1542 }
1543 }
1544
1545 /* Device speed */
1546 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1547 if (rc) {
1548 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1549 nc->full_name, rc);
1550 goto err_out;
1551 }
1552 spi->max_speed_hz = value;
1553
Pantelis Antoniouaff5e3f2014-10-29 10:40:37 +02001554 /* Store a pointer to the node in the device structure */
1555 of_node_get(nc);
1556 spi->dev.of_node = nc;
1557
1558 /* Register the new device */
Pantelis Antoniouaff5e3f2014-10-29 10:40:37 +02001559 rc = spi_add_device(spi);
1560 if (rc) {
1561 dev_err(&master->dev, "spi_device register error %s\n",
1562 nc->full_name);
1563 goto err_out;
1564 }
1565
1566 return spi;
1567
1568err_out:
1569 spi_dev_put(spi);
1570 return ERR_PTR(rc);
1571}
1572
Grant Likelyd57a4282012-04-07 14:16:53 -06001573/**
1574 * of_register_spi_devices() - Register child devices onto the SPI bus
1575 * @master: Pointer to spi_master device
1576 *
1577 * Registers an spi_device for each child node of master node which has a 'reg'
1578 * property.
1579 */
1580static void of_register_spi_devices(struct spi_master *master)
1581{
1582 struct spi_device *spi;
1583 struct device_node *nc;
Grant Likelyd57a4282012-04-07 14:16:53 -06001584
1585 if (!master->dev.of_node)
1586 return;
1587
Alexander Sverdlinf3b61592012-11-29 08:59:29 +01001588 for_each_available_child_of_node(master->dev.of_node, nc) {
Geert Uytterhoevenbd6c1642015-11-30 15:28:07 +01001589 if (of_node_test_and_set_flag(nc, OF_POPULATED))
1590 continue;
Pantelis Antoniouaff5e3f2014-10-29 10:40:37 +02001591 spi = of_register_spi_device(master, nc);
1592 if (IS_ERR(spi))
1593 dev_warn(&master->dev, "Failed to create SPI device for %s\n",
Grant Likelyd57a4282012-04-07 14:16:53 -06001594 nc->full_name);
Grant Likelyd57a4282012-04-07 14:16:53 -06001595 }
1596}
1597#else
1598static void of_register_spi_devices(struct spi_master *master) { }
1599#endif
1600
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001601#ifdef CONFIG_ACPI
1602static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1603{
1604 struct spi_device *spi = data;
Mika Westerberga0a90712016-02-08 17:14:28 +02001605 struct spi_master *master = spi->master;
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001606
1607 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1608 struct acpi_resource_spi_serialbus *sb;
1609
1610 sb = &ares->data.spi_serial_bus;
1611 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
Mika Westerberga0a90712016-02-08 17:14:28 +02001612 /*
1613 * ACPI DeviceSelection numbering is handled by the
1614 * host controller driver in Windows and can vary
1615 * from driver to driver. In Linux we always expect
1616 * 0 .. max - 1 so we need to ask the driver to
1617 * translate between the two schemes.
1618 */
1619 if (master->fw_translate_cs) {
1620 int cs = master->fw_translate_cs(master,
1621 sb->device_selection);
1622 if (cs < 0)
1623 return cs;
1624 spi->chip_select = cs;
1625 } else {
1626 spi->chip_select = sb->device_selection;
1627 }
1628
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001629 spi->max_speed_hz = sb->connection_speed;
1630
1631 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1632 spi->mode |= SPI_CPHA;
1633 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1634 spi->mode |= SPI_CPOL;
1635 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1636 spi->mode |= SPI_CS_HIGH;
1637 }
1638 } else if (spi->irq < 0) {
1639 struct resource r;
1640
1641 if (acpi_dev_resource_interrupt(ares, 0, &r))
1642 spi->irq = r.start;
1643 }
1644
1645 /* Always tell the ACPI core to skip this resource */
1646 return 1;
1647}
1648
1649static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1650 void *data, void **return_value)
1651{
1652 struct spi_master *master = data;
1653 struct list_head resource_list;
1654 struct acpi_device *adev;
1655 struct spi_device *spi;
1656 int ret;
1657
1658 if (acpi_bus_get_device(handle, &adev))
1659 return AE_OK;
1660 if (acpi_bus_get_status(adev) || !adev->status.present)
1661 return AE_OK;
1662
1663 spi = spi_alloc_device(master);
1664 if (!spi) {
1665 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1666 dev_name(&adev->dev));
1667 return AE_NO_MEMORY;
1668 }
1669
Rafael J. Wysocki7b199812013-11-11 22:41:56 +01001670 ACPI_COMPANION_SET(&spi->dev, adev);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001671 spi->irq = -1;
1672
1673 INIT_LIST_HEAD(&resource_list);
1674 ret = acpi_dev_get_resources(adev, &resource_list,
1675 acpi_spi_add_resource, spi);
1676 acpi_dev_free_resource_list(&resource_list);
1677
1678 if (ret < 0 || !spi->max_speed_hz) {
1679 spi_dev_put(spi);
1680 return AE_OK;
1681 }
1682
Christophe RICARD33ada672015-12-23 23:25:35 +01001683 if (spi->irq < 0)
1684 spi->irq = acpi_dev_gpio_irq_get(adev, 0);
1685
Mika Westerberg33cf00e2013-10-10 13:28:48 +03001686 adev->power.flags.ignore_parent = true;
Jarkko Nikulacf9eb392013-10-10 17:19:17 +03001687 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001688 if (spi_add_device(spi)) {
Mika Westerberg33cf00e2013-10-10 13:28:48 +03001689 adev->power.flags.ignore_parent = false;
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001690 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1691 dev_name(&adev->dev));
1692 spi_dev_put(spi);
1693 }
1694
1695 return AE_OK;
1696}
1697
1698static void acpi_register_spi_devices(struct spi_master *master)
1699{
1700 acpi_status status;
1701 acpi_handle handle;
1702
Rafael J. Wysocki29896172013-04-01 00:21:08 +00001703 handle = ACPI_HANDLE(master->dev.parent);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001704 if (!handle)
1705 return;
1706
1707 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1708 acpi_spi_add_device, NULL,
1709 master, NULL);
1710 if (ACPI_FAILURE(status))
1711 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1712}
1713#else
1714static inline void acpi_register_spi_devices(struct spi_master *master) {}
1715#endif /* CONFIG_ACPI */
1716
Tony Jones49dce682007-10-16 01:27:48 -07001717static void spi_master_release(struct device *dev)
David Brownell8ae12a02006-01-08 13:34:19 -08001718{
1719 struct spi_master *master;
1720
Tony Jones49dce682007-10-16 01:27:48 -07001721 master = container_of(dev, struct spi_master, dev);
David Brownell8ae12a02006-01-08 13:34:19 -08001722 kfree(master);
1723}
1724
1725static struct class spi_master_class = {
1726 .name = "spi_master",
1727 .owner = THIS_MODULE,
Tony Jones49dce682007-10-16 01:27:48 -07001728 .dev_release = spi_master_release,
Martin Sperleca2ebc2015-06-22 13:00:36 +00001729 .dev_groups = spi_master_groups,
David Brownell8ae12a02006-01-08 13:34:19 -08001730};
1731
1732
1733/**
1734 * spi_alloc_master - allocate SPI master controller
1735 * @dev: the controller, possibly using the platform_bus
David Brownell33e34dc2007-05-08 00:32:21 -07001736 * @size: how much zeroed driver-private data to allocate; the pointer to this
Tony Jones49dce682007-10-16 01:27:48 -07001737 * memory is in the driver_data field of the returned device,
David Brownell0c868462006-01-08 13:34:25 -08001738 * accessible with spi_master_get_devdata().
David Brownell33e34dc2007-05-08 00:32:21 -07001739 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001740 *
1741 * This call is used only by SPI master controller drivers, which are the
1742 * only ones directly touching chip registers. It's how they allocate
dmitry pervushinba1a0512006-05-20 15:00:14 -07001743 * an spi_master structure, prior to calling spi_register_master().
David Brownell8ae12a02006-01-08 13:34:19 -08001744 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001745 * This must be called from context that can sleep.
David Brownell8ae12a02006-01-08 13:34:19 -08001746 *
1747 * The caller is responsible for assigning the bus number and initializing
dmitry pervushinba1a0512006-05-20 15:00:14 -07001748 * the master's methods before calling spi_register_master(); and (after errors
Guenter Roecka394d632015-09-06 01:46:54 +03001749 * adding the device) calling spi_master_put() to prevent a memory leak.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001750 *
1751 * Return: the SPI master structure on success, else NULL.
David Brownell8ae12a02006-01-08 13:34:19 -08001752 */
Adrian Bunke9d5a462007-03-26 21:32:23 -08001753struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
David Brownell8ae12a02006-01-08 13:34:19 -08001754{
1755 struct spi_master *master;
1756
David Brownell0c868462006-01-08 13:34:25 -08001757 if (!dev)
1758 return NULL;
1759
Jingoo Han5fe5f052013-10-14 10:31:51 +09001760 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
David Brownell8ae12a02006-01-08 13:34:19 -08001761 if (!master)
1762 return NULL;
1763
Tony Jones49dce682007-10-16 01:27:48 -07001764 device_initialize(&master->dev);
Grant Likely1e8a52e2012-05-19 23:42:08 -06001765 master->bus_num = -1;
1766 master->num_chipselect = 1;
Tony Jones49dce682007-10-16 01:27:48 -07001767 master->dev.class = &spi_master_class;
Johan Hovold157f38f2015-12-14 16:16:19 +01001768 master->dev.parent = dev;
Linus Walleijd7e2ee22016-04-11 13:51:03 +02001769 pm_suspend_ignore_children(&master->dev, true);
David Brownell0c868462006-01-08 13:34:25 -08001770 spi_master_set_devdata(master, &master[1]);
David Brownell8ae12a02006-01-08 13:34:19 -08001771
1772 return master;
1773}
1774EXPORT_SYMBOL_GPL(spi_alloc_master);
1775
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001776#ifdef CONFIG_OF
1777static int of_spi_register_master(struct spi_master *master)
1778{
Grant Likelye80beb22013-02-12 17:48:37 +00001779 int nb, i, *cs;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001780 struct device_node *np = master->dev.of_node;
1781
1782 if (!np)
1783 return 0;
1784
1785 nb = of_gpio_named_count(np, "cs-gpios");
Jingoo Han5fe5f052013-10-14 10:31:51 +09001786 master->num_chipselect = max_t(int, nb, master->num_chipselect);
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001787
Andreas Larsson8ec5d842013-02-13 14:23:24 +01001788 /* Return error only for an incorrectly formed cs-gpios property */
1789 if (nb == 0 || nb == -ENOENT)
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001790 return 0;
Andreas Larsson8ec5d842013-02-13 14:23:24 +01001791 else if (nb < 0)
1792 return nb;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001793
1794 cs = devm_kzalloc(&master->dev,
1795 sizeof(int) * master->num_chipselect,
1796 GFP_KERNEL);
1797 master->cs_gpios = cs;
1798
1799 if (!master->cs_gpios)
1800 return -ENOMEM;
1801
Andreas Larsson0da83bb2013-01-29 15:53:40 +01001802 for (i = 0; i < master->num_chipselect; i++)
Andreas Larsson446411e2013-02-13 14:20:25 +01001803 cs[i] = -ENOENT;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001804
1805 for (i = 0; i < nb; i++)
1806 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1807
1808 return 0;
1809}
1810#else
1811static int of_spi_register_master(struct spi_master *master)
1812{
1813 return 0;
1814}
1815#endif
1816
David Brownell8ae12a02006-01-08 13:34:19 -08001817/**
1818 * spi_register_master - register SPI master controller
1819 * @master: initialized master, originally from spi_alloc_master()
David Brownell33e34dc2007-05-08 00:32:21 -07001820 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001821 *
1822 * SPI master controllers connect to their drivers using some non-SPI bus,
1823 * such as the platform bus. The final stage of probe() in that code
1824 * includes calling spi_register_master() to hook up to this SPI bus glue.
1825 *
1826 * SPI controllers use board specific (often SOC specific) bus numbers,
1827 * and board-specific addressing for SPI devices combines those numbers
1828 * with chip select numbers. Since SPI does not directly support dynamic
1829 * device identification, boards need configuration tables telling which
1830 * chip is at which address.
1831 *
1832 * This must be called from context that can sleep. It returns zero on
1833 * success, else a negative error code (dropping the master's refcount).
David Brownell0c868462006-01-08 13:34:25 -08001834 * After a successful return, the caller is responsible for calling
1835 * spi_unregister_master().
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001836 *
1837 * Return: zero on success, else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001838 */
Adrian Bunke9d5a462007-03-26 21:32:23 -08001839int spi_register_master(struct spi_master *master)
David Brownell8ae12a02006-01-08 13:34:19 -08001840{
David Brownelle44a45a2007-06-03 13:50:40 -07001841 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
Tony Jones49dce682007-10-16 01:27:48 -07001842 struct device *dev = master->dev.parent;
Feng Tang2b9603a2010-08-02 15:52:15 +08001843 struct boardinfo *bi;
David Brownell8ae12a02006-01-08 13:34:19 -08001844 int status = -ENODEV;
1845 int dynamic = 0;
1846
David Brownell0c868462006-01-08 13:34:25 -08001847 if (!dev)
1848 return -ENODEV;
1849
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001850 status = of_spi_register_master(master);
1851 if (status)
1852 return status;
1853
David Brownell082c8cb2007-07-31 00:39:45 -07001854 /* even if it's just one always-selected device, there must
1855 * be at least one chipselect
1856 */
1857 if (master->num_chipselect == 0)
1858 return -EINVAL;
1859
Grant Likelybb297852012-12-21 19:32:09 +00001860 if ((master->bus_num < 0) && master->dev.of_node)
1861 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1862
David Brownell8ae12a02006-01-08 13:34:19 -08001863 /* convention: dynamically assigned bus IDs count down from the max */
David Brownella020ed72006-04-03 15:49:04 -07001864 if (master->bus_num < 0) {
David Brownell082c8cb2007-07-31 00:39:45 -07001865 /* FIXME switch to an IDR based scheme, something like
1866 * I2C now uses, so we can't run out of "dynamic" IDs
1867 */
David Brownell8ae12a02006-01-08 13:34:19 -08001868 master->bus_num = atomic_dec_return(&dyn_bus_id);
David Brownellb8852442006-01-08 13:34:23 -08001869 dynamic = 1;
David Brownell8ae12a02006-01-08 13:34:19 -08001870 }
1871
Mark Brown5424d432014-12-10 17:40:53 +00001872 INIT_LIST_HEAD(&master->queue);
1873 spin_lock_init(&master->queue_lock);
Ernst Schwabcf32b712010-06-28 17:49:29 -07001874 spin_lock_init(&master->bus_lock_spinlock);
1875 mutex_init(&master->bus_lock_mutex);
1876 master->bus_lock_flag = 0;
Mark Brownb1589352013-10-05 11:50:40 +01001877 init_completion(&master->xfer_completion);
Mark Brown6ad45a22014-02-02 13:47:47 +00001878 if (!master->max_dma_len)
1879 master->max_dma_len = INT_MAX;
Ernst Schwabcf32b712010-06-28 17:49:29 -07001880
David Brownell8ae12a02006-01-08 13:34:19 -08001881 /* register the device, then userspace will see it.
1882 * registration fails if the bus ID is in use.
1883 */
Kay Sievers35f74fc2009-01-06 10:44:37 -08001884 dev_set_name(&master->dev, "spi%u", master->bus_num);
Tony Jones49dce682007-10-16 01:27:48 -07001885 status = device_add(&master->dev);
David Brownellb8852442006-01-08 13:34:23 -08001886 if (status < 0)
David Brownell8ae12a02006-01-08 13:34:19 -08001887 goto done;
Kay Sievers35f74fc2009-01-06 10:44:37 -08001888 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
David Brownell8ae12a02006-01-08 13:34:19 -08001889 dynamic ? " (dynamic)" : "");
1890
Linus Walleijffbbdd212012-02-22 10:05:38 +01001891 /* If we're using a queued driver, start the queue */
1892 if (master->transfer)
1893 dev_info(dev, "master is unqueued, this is deprecated\n");
1894 else {
1895 status = spi_master_initialize_queue(master);
1896 if (status) {
Axel Line93b0722013-08-31 20:25:52 +08001897 device_del(&master->dev);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001898 goto done;
1899 }
1900 }
Martin Sperleca2ebc2015-06-22 13:00:36 +00001901 /* add statistics */
1902 spin_lock_init(&master->statistics.lock);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001903
Feng Tang2b9603a2010-08-02 15:52:15 +08001904 mutex_lock(&board_lock);
1905 list_add_tail(&master->list, &spi_master_list);
1906 list_for_each_entry(bi, &board_list, list)
1907 spi_match_master_to_boardinfo(master, &bi->board_info);
1908 mutex_unlock(&board_lock);
1909
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001910 /* Register devices from the device tree and ACPI */
Anatolij Gustschin12b15e82010-07-27 22:35:58 +02001911 of_register_spi_devices(master);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001912 acpi_register_spi_devices(master);
David Brownell8ae12a02006-01-08 13:34:19 -08001913done:
1914 return status;
1915}
1916EXPORT_SYMBOL_GPL(spi_register_master);
1917
Mark Brown666d5b42013-08-31 18:50:52 +01001918static void devm_spi_unregister(struct device *dev, void *res)
1919{
1920 spi_unregister_master(*(struct spi_master **)res);
1921}
1922
1923/**
1924 * dev_spi_register_master - register managed SPI master controller
1925 * @dev: device managing SPI master
1926 * @master: initialized master, originally from spi_alloc_master()
1927 * Context: can sleep
1928 *
1929 * Register a SPI device as with spi_register_master() which will
1930 * automatically be unregister
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02001931 *
1932 * Return: zero on success, else a negative error code.
Mark Brown666d5b42013-08-31 18:50:52 +01001933 */
1934int devm_spi_register_master(struct device *dev, struct spi_master *master)
1935{
1936 struct spi_master **ptr;
1937 int ret;
1938
1939 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1940 if (!ptr)
1941 return -ENOMEM;
1942
1943 ret = spi_register_master(master);
Stephen Warren4b928942013-11-21 16:11:15 -07001944 if (!ret) {
Mark Brown666d5b42013-08-31 18:50:52 +01001945 *ptr = master;
1946 devres_add(dev, ptr);
1947 } else {
1948 devres_free(ptr);
1949 }
1950
1951 return ret;
1952}
1953EXPORT_SYMBOL_GPL(devm_spi_register_master);
1954
David Lamparter34860082010-08-30 23:54:17 +02001955static int __unregister(struct device *dev, void *null)
David Brownell8ae12a02006-01-08 13:34:19 -08001956{
David Lamparter34860082010-08-30 23:54:17 +02001957 spi_unregister_device(to_spi_device(dev));
David Brownell8ae12a02006-01-08 13:34:19 -08001958 return 0;
1959}
1960
1961/**
1962 * spi_unregister_master - unregister SPI master controller
1963 * @master: the master being unregistered
David Brownell33e34dc2007-05-08 00:32:21 -07001964 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001965 *
1966 * This call is used only by SPI master controller drivers, which are the
1967 * only ones directly touching chip registers.
1968 *
1969 * This must be called from context that can sleep.
1970 */
1971void spi_unregister_master(struct spi_master *master)
1972{
Jeff Garzik89fc9a12006-12-06 20:35:35 -08001973 int dummy;
1974
Linus Walleijffbbdd212012-02-22 10:05:38 +01001975 if (master->queued) {
1976 if (spi_destroy_queue(master))
1977 dev_err(&master->dev, "queue remove failed\n");
1978 }
1979
Feng Tang2b9603a2010-08-02 15:52:15 +08001980 mutex_lock(&board_lock);
1981 list_del(&master->list);
1982 mutex_unlock(&board_lock);
1983
Sebastian Andrzej Siewior97dbf372010-12-21 17:24:31 -08001984 dummy = device_for_each_child(&master->dev, NULL, __unregister);
Tony Jones49dce682007-10-16 01:27:48 -07001985 device_unregister(&master->dev);
David Brownell8ae12a02006-01-08 13:34:19 -08001986}
1987EXPORT_SYMBOL_GPL(spi_unregister_master);
1988
Linus Walleijffbbdd212012-02-22 10:05:38 +01001989int spi_master_suspend(struct spi_master *master)
1990{
1991 int ret;
1992
1993 /* Basically no-ops for non-queued masters */
1994 if (!master->queued)
1995 return 0;
1996
1997 ret = spi_stop_queue(master);
1998 if (ret)
1999 dev_err(&master->dev, "queue stop failed\n");
2000
2001 return ret;
2002}
2003EXPORT_SYMBOL_GPL(spi_master_suspend);
2004
2005int spi_master_resume(struct spi_master *master)
2006{
2007 int ret;
2008
2009 if (!master->queued)
2010 return 0;
2011
2012 ret = spi_start_queue(master);
2013 if (ret)
2014 dev_err(&master->dev, "queue restart failed\n");
2015
2016 return ret;
2017}
2018EXPORT_SYMBOL_GPL(spi_master_resume);
2019
Michał Mirosław9f3b7952013-02-01 20:40:17 +01002020static int __spi_master_match(struct device *dev, const void *data)
Dave Young5ed2c832008-01-22 15:14:18 +08002021{
2022 struct spi_master *m;
Michał Mirosław9f3b7952013-02-01 20:40:17 +01002023 const u16 *bus_num = data;
Dave Young5ed2c832008-01-22 15:14:18 +08002024
2025 m = container_of(dev, struct spi_master, dev);
2026 return m->bus_num == *bus_num;
2027}
2028
David Brownell8ae12a02006-01-08 13:34:19 -08002029/**
2030 * spi_busnum_to_master - look up master associated with bus_num
2031 * @bus_num: the master's bus number
David Brownell33e34dc2007-05-08 00:32:21 -07002032 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08002033 *
2034 * This call may be used with devices that are registered after
2035 * arch init time. It returns a refcounted pointer to the relevant
2036 * spi_master (which the caller must release), or NULL if there is
2037 * no such master registered.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002038 *
2039 * Return: the SPI master structure on success, else NULL.
David Brownell8ae12a02006-01-08 13:34:19 -08002040 */
2041struct spi_master *spi_busnum_to_master(u16 bus_num)
2042{
Tony Jones49dce682007-10-16 01:27:48 -07002043 struct device *dev;
Atsushi Nemoto1e9a51d2007-01-26 00:56:54 -08002044 struct spi_master *master = NULL;
David Brownell8ae12a02006-01-08 13:34:19 -08002045
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -04002046 dev = class_find_device(&spi_master_class, NULL, &bus_num,
Dave Young5ed2c832008-01-22 15:14:18 +08002047 __spi_master_match);
2048 if (dev)
2049 master = container_of(dev, struct spi_master, dev);
2050 /* reference got in class_find_device */
Atsushi Nemoto1e9a51d2007-01-26 00:56:54 -08002051 return master;
David Brownell8ae12a02006-01-08 13:34:19 -08002052}
2053EXPORT_SYMBOL_GPL(spi_busnum_to_master);
2054
Martin Sperld780c372015-12-14 15:20:18 +00002055/*-------------------------------------------------------------------------*/
2056
2057/* Core methods for SPI resource management */
2058
2059/**
2060 * spi_res_alloc - allocate a spi resource that is life-cycle managed
2061 * during the processing of a spi_message while using
2062 * spi_transfer_one
2063 * @spi: the spi device for which we allocate memory
2064 * @release: the release code to execute for this resource
2065 * @size: size to alloc and return
2066 * @gfp: GFP allocation flags
2067 *
2068 * Return: the pointer to the allocated data
2069 *
2070 * This may get enhanced in the future to allocate from a memory pool
2071 * of the @spi_device or @spi_master to avoid repeated allocations.
2072 */
2073void *spi_res_alloc(struct spi_device *spi,
2074 spi_res_release_t release,
2075 size_t size, gfp_t gfp)
2076{
2077 struct spi_res *sres;
2078
2079 sres = kzalloc(sizeof(*sres) + size, gfp);
2080 if (!sres)
2081 return NULL;
2082
2083 INIT_LIST_HEAD(&sres->entry);
2084 sres->release = release;
2085
2086 return sres->data;
2087}
2088EXPORT_SYMBOL_GPL(spi_res_alloc);
2089
2090/**
2091 * spi_res_free - free an spi resource
2092 * @res: pointer to the custom data of a resource
2093 *
2094 */
2095void spi_res_free(void *res)
2096{
2097 struct spi_res *sres = container_of(res, struct spi_res, data);
2098
2099 if (!res)
2100 return;
2101
2102 WARN_ON(!list_empty(&sres->entry));
2103 kfree(sres);
2104}
2105EXPORT_SYMBOL_GPL(spi_res_free);
2106
2107/**
2108 * spi_res_add - add a spi_res to the spi_message
2109 * @message: the spi message
2110 * @res: the spi_resource
2111 */
2112void spi_res_add(struct spi_message *message, void *res)
2113{
2114 struct spi_res *sres = container_of(res, struct spi_res, data);
2115
2116 WARN_ON(!list_empty(&sres->entry));
2117 list_add_tail(&sres->entry, &message->resources);
2118}
2119EXPORT_SYMBOL_GPL(spi_res_add);
2120
2121/**
2122 * spi_res_release - release all spi resources for this message
2123 * @master: the @spi_master
2124 * @message: the @spi_message
2125 */
2126void spi_res_release(struct spi_master *master,
2127 struct spi_message *message)
2128{
2129 struct spi_res *res;
2130
2131 while (!list_empty(&message->resources)) {
2132 res = list_last_entry(&message->resources,
2133 struct spi_res, entry);
2134
2135 if (res->release)
2136 res->release(master, message, res->data);
2137
2138 list_del(&res->entry);
2139
2140 kfree(res);
2141 }
2142}
2143EXPORT_SYMBOL_GPL(spi_res_release);
David Brownell8ae12a02006-01-08 13:34:19 -08002144
2145/*-------------------------------------------------------------------------*/
2146
Martin Sperl523baf5a2015-12-14 15:20:19 +00002147/* Core methods for spi_message alterations */
2148
2149static void __spi_replace_transfers_release(struct spi_master *master,
2150 struct spi_message *msg,
2151 void *res)
2152{
2153 struct spi_replaced_transfers *rxfer = res;
2154 size_t i;
2155
2156 /* call extra callback if requested */
2157 if (rxfer->release)
2158 rxfer->release(master, msg, res);
2159
2160 /* insert replaced transfers back into the message */
2161 list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
2162
2163 /* remove the formerly inserted entries */
2164 for (i = 0; i < rxfer->inserted; i++)
2165 list_del(&rxfer->inserted_transfers[i].transfer_list);
2166}
2167
2168/**
2169 * spi_replace_transfers - replace transfers with several transfers
2170 * and register change with spi_message.resources
2171 * @msg: the spi_message we work upon
2172 * @xfer_first: the first spi_transfer we want to replace
2173 * @remove: number of transfers to remove
2174 * @insert: the number of transfers we want to insert instead
2175 * @release: extra release code necessary in some circumstances
2176 * @extradatasize: extra data to allocate (with alignment guarantees
2177 * of struct @spi_transfer)
Martin Sperl05885392016-02-18 15:53:11 +00002178 * @gfp: gfp flags
Martin Sperl523baf5a2015-12-14 15:20:19 +00002179 *
2180 * Returns: pointer to @spi_replaced_transfers,
2181 * PTR_ERR(...) in case of errors.
2182 */
2183struct spi_replaced_transfers *spi_replace_transfers(
2184 struct spi_message *msg,
2185 struct spi_transfer *xfer_first,
2186 size_t remove,
2187 size_t insert,
2188 spi_replaced_release_t release,
2189 size_t extradatasize,
2190 gfp_t gfp)
2191{
2192 struct spi_replaced_transfers *rxfer;
2193 struct spi_transfer *xfer;
2194 size_t i;
2195
2196 /* allocate the structure using spi_res */
2197 rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
2198 insert * sizeof(struct spi_transfer)
2199 + sizeof(struct spi_replaced_transfers)
2200 + extradatasize,
2201 gfp);
2202 if (!rxfer)
2203 return ERR_PTR(-ENOMEM);
2204
2205 /* the release code to invoke before running the generic release */
2206 rxfer->release = release;
2207
2208 /* assign extradata */
2209 if (extradatasize)
2210 rxfer->extradata =
2211 &rxfer->inserted_transfers[insert];
2212
2213 /* init the replaced_transfers list */
2214 INIT_LIST_HEAD(&rxfer->replaced_transfers);
2215
2216 /* assign the list_entry after which we should reinsert
2217 * the @replaced_transfers - it may be spi_message.messages!
2218 */
2219 rxfer->replaced_after = xfer_first->transfer_list.prev;
2220
2221 /* remove the requested number of transfers */
2222 for (i = 0; i < remove; i++) {
2223 /* if the entry after replaced_after it is msg->transfers
2224 * then we have been requested to remove more transfers
2225 * than are in the list
2226 */
2227 if (rxfer->replaced_after->next == &msg->transfers) {
2228 dev_err(&msg->spi->dev,
2229 "requested to remove more spi_transfers than are available\n");
2230 /* insert replaced transfers back into the message */
2231 list_splice(&rxfer->replaced_transfers,
2232 rxfer->replaced_after);
2233
2234 /* free the spi_replace_transfer structure */
2235 spi_res_free(rxfer);
2236
2237 /* and return with an error */
2238 return ERR_PTR(-EINVAL);
2239 }
2240
2241 /* remove the entry after replaced_after from list of
2242 * transfers and add it to list of replaced_transfers
2243 */
2244 list_move_tail(rxfer->replaced_after->next,
2245 &rxfer->replaced_transfers);
2246 }
2247
2248 /* create copy of the given xfer with identical settings
2249 * based on the first transfer to get removed
2250 */
2251 for (i = 0; i < insert; i++) {
2252 /* we need to run in reverse order */
2253 xfer = &rxfer->inserted_transfers[insert - 1 - i];
2254
2255 /* copy all spi_transfer data */
2256 memcpy(xfer, xfer_first, sizeof(*xfer));
2257
2258 /* add to list */
2259 list_add(&xfer->transfer_list, rxfer->replaced_after);
2260
2261 /* clear cs_change and delay_usecs for all but the last */
2262 if (i) {
2263 xfer->cs_change = false;
2264 xfer->delay_usecs = 0;
2265 }
2266 }
2267
2268 /* set up inserted */
2269 rxfer->inserted = insert;
2270
2271 /* and register it with spi_res/spi_message */
2272 spi_res_add(msg, rxfer);
2273
2274 return rxfer;
2275}
2276EXPORT_SYMBOL_GPL(spi_replace_transfers);
2277
Fabio Estevam08933412016-02-14 13:33:50 -02002278static int __spi_split_transfer_maxsize(struct spi_master *master,
2279 struct spi_message *msg,
2280 struct spi_transfer **xferp,
2281 size_t maxsize,
2282 gfp_t gfp)
Martin Sperld9f12122015-12-14 15:20:20 +00002283{
2284 struct spi_transfer *xfer = *xferp, *xfers;
2285 struct spi_replaced_transfers *srt;
2286 size_t offset;
2287 size_t count, i;
2288
2289 /* warn once about this fact that we are splitting a transfer */
2290 dev_warn_once(&msg->spi->dev,
Fabio Estevam7d62f512016-02-17 15:42:27 -02002291 "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
Martin Sperld9f12122015-12-14 15:20:20 +00002292 xfer->len, maxsize);
2293
2294 /* calculate how many we have to replace */
2295 count = DIV_ROUND_UP(xfer->len, maxsize);
2296
2297 /* create replacement */
2298 srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
Dan Carpenter657d32e2016-02-12 09:38:33 +03002299 if (IS_ERR(srt))
2300 return PTR_ERR(srt);
Martin Sperld9f12122015-12-14 15:20:20 +00002301 xfers = srt->inserted_transfers;
2302
2303 /* now handle each of those newly inserted spi_transfers
2304 * note that the replacements spi_transfers all are preset
2305 * to the same values as *xferp, so tx_buf, rx_buf and len
2306 * are all identical (as well as most others)
2307 * so we just have to fix up len and the pointers.
2308 *
2309 * this also includes support for the depreciated
2310 * spi_message.is_dma_mapped interface
2311 */
2312
2313 /* the first transfer just needs the length modified, so we
2314 * run it outside the loop
2315 */
Fabio Estevamc8dab772016-02-17 15:42:28 -02002316 xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
Martin Sperld9f12122015-12-14 15:20:20 +00002317
2318 /* all the others need rx_buf/tx_buf also set */
2319 for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
2320 /* update rx_buf, tx_buf and dma */
2321 if (xfers[i].rx_buf)
2322 xfers[i].rx_buf += offset;
2323 if (xfers[i].rx_dma)
2324 xfers[i].rx_dma += offset;
2325 if (xfers[i].tx_buf)
2326 xfers[i].tx_buf += offset;
2327 if (xfers[i].tx_dma)
2328 xfers[i].tx_dma += offset;
2329
2330 /* update length */
2331 xfers[i].len = min(maxsize, xfers[i].len - offset);
2332 }
2333
2334 /* we set up xferp to the last entry we have inserted,
2335 * so that we skip those already split transfers
2336 */
2337 *xferp = &xfers[count - 1];
2338
2339 /* increment statistics counters */
2340 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2341 transfers_split_maxsize);
2342 SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
2343 transfers_split_maxsize);
2344
2345 return 0;
2346}
2347
2348/**
2349 * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
2350 * when an individual transfer exceeds a
2351 * certain size
2352 * @master: the @spi_master for this transfer
Masanari Iida3700ce92016-02-22 20:33:44 +09002353 * @msg: the @spi_message to transform
2354 * @maxsize: the maximum when to apply this
Javier Martinez Canillas10f11a22016-03-10 15:01:14 -03002355 * @gfp: GFP allocation flags
Martin Sperld9f12122015-12-14 15:20:20 +00002356 *
2357 * Return: status of transformation
2358 */
2359int spi_split_transfers_maxsize(struct spi_master *master,
2360 struct spi_message *msg,
2361 size_t maxsize,
2362 gfp_t gfp)
2363{
2364 struct spi_transfer *xfer;
2365 int ret;
2366
2367 /* iterate over the transfer_list,
2368 * but note that xfer is advanced to the last transfer inserted
2369 * to avoid checking sizes again unnecessarily (also xfer does
2370 * potentiall belong to a different list by the time the
2371 * replacement has happened
2372 */
2373 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
2374 if (xfer->len > maxsize) {
2375 ret = __spi_split_transfer_maxsize(
2376 master, msg, &xfer, maxsize, gfp);
2377 if (ret)
2378 return ret;
2379 }
2380 }
2381
2382 return 0;
2383}
2384EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
David Brownell8ae12a02006-01-08 13:34:19 -08002385
2386/*-------------------------------------------------------------------------*/
2387
David Brownell7d077192009-06-17 16:26:03 -07002388/* Core methods for SPI master protocol drivers. Some of the
2389 * other core methods are currently defined as inline functions.
2390 */
2391
Stefan Brüns63ab6452015-08-23 16:06:30 +02002392static int __spi_validate_bits_per_word(struct spi_master *master, u8 bits_per_word)
2393{
2394 if (master->bits_per_word_mask) {
2395 /* Only 32 bits fit in the mask */
2396 if (bits_per_word > 32)
2397 return -EINVAL;
2398 if (!(master->bits_per_word_mask &
2399 SPI_BPW_MASK(bits_per_word)))
2400 return -EINVAL;
2401 }
2402
2403 return 0;
2404}
2405
David Brownell7d077192009-06-17 16:26:03 -07002406/**
2407 * spi_setup - setup SPI mode and clock rate
2408 * @spi: the device whose settings are being modified
2409 * Context: can sleep, and no requests are queued to the device
2410 *
2411 * SPI protocol drivers may need to update the transfer mode if the
2412 * device doesn't work with its default. They may likewise need
2413 * to update clock rates or word sizes from initial values. This function
2414 * changes those settings, and must be called from a context that can sleep.
2415 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
2416 * effect the next time the device is selected and data is transferred to
2417 * or from it. When this function returns, the spi device is deselected.
2418 *
2419 * Note that this call will fail if the protocol driver specifies an option
2420 * that the underlying controller or its driver does not support. For
2421 * example, not all hardware supports wire transfers using nine bit words,
2422 * LSB-first wire encoding, or active-high chipselects.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002423 *
2424 * Return: zero on success, else a negative error code.
David Brownell7d077192009-06-17 16:26:03 -07002425 */
2426int spi_setup(struct spi_device *spi)
2427{
Geert Uytterhoeven83596fb2014-04-14 19:39:53 +02002428 unsigned bad_bits, ugly_bits;
Andy Shevchenko5ab8d262015-10-14 22:43:07 +03002429 int status;
David Brownell7d077192009-06-17 16:26:03 -07002430
wangyuhangf477b7f2013-08-11 18:15:17 +08002431 /* check mode to prevent that DUAL and QUAD set at the same time
2432 */
2433 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
2434 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
2435 dev_err(&spi->dev,
2436 "setup: can not select dual and quad at the same time\n");
2437 return -EINVAL;
2438 }
2439 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
2440 */
2441 if ((spi->mode & SPI_3WIRE) && (spi->mode &
2442 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
2443 return -EINVAL;
David Brownelle7db06b2009-06-17 16:26:04 -07002444 /* help drivers fail *cleanly* when they need options
2445 * that aren't supported with their current master
2446 */
2447 bad_bits = spi->mode & ~spi->master->mode_bits;
Geert Uytterhoeven83596fb2014-04-14 19:39:53 +02002448 ugly_bits = bad_bits &
2449 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD);
2450 if (ugly_bits) {
2451 dev_warn(&spi->dev,
2452 "setup: ignoring unsupported mode bits %x\n",
2453 ugly_bits);
2454 spi->mode &= ~ugly_bits;
2455 bad_bits &= ~ugly_bits;
2456 }
David Brownelle7db06b2009-06-17 16:26:04 -07002457 if (bad_bits) {
Linus Walleijeb288a12010-10-21 21:06:44 +02002458 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
David Brownelle7db06b2009-06-17 16:26:04 -07002459 bad_bits);
2460 return -EINVAL;
2461 }
2462
David Brownell7d077192009-06-17 16:26:03 -07002463 if (!spi->bits_per_word)
2464 spi->bits_per_word = 8;
2465
Andy Shevchenko5ab8d262015-10-14 22:43:07 +03002466 status = __spi_validate_bits_per_word(spi->master, spi->bits_per_word);
2467 if (status)
2468 return status;
Stefan Brüns63ab6452015-08-23 16:06:30 +02002469
Axel Lin052eb2d42014-02-10 00:08:05 +08002470 if (!spi->max_speed_hz)
2471 spi->max_speed_hz = spi->master->max_speed_hz;
2472
Laxman Dewangancaae0702012-11-09 14:35:22 +05302473 if (spi->master->setup)
2474 status = spi->master->setup(spi);
David Brownell7d077192009-06-17 16:26:03 -07002475
Franklin S Cooper Jrabeedb02015-10-16 10:29:03 -05002476 spi_set_cs(spi, false);
2477
Jingoo Han5fe5f052013-10-14 10:31:51 +09002478 dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
David Brownell7d077192009-06-17 16:26:03 -07002479 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
2480 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
2481 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
2482 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
2483 (spi->mode & SPI_LOOP) ? "loopback, " : "",
2484 spi->bits_per_word, spi->max_speed_hz,
2485 status);
2486
2487 return status;
2488}
2489EXPORT_SYMBOL_GPL(spi_setup);
2490
Mark Brown90808732013-11-13 23:44:15 +00002491static int __spi_validate(struct spi_device *spi, struct spi_message *message)
Ernst Schwabcf32b712010-06-28 17:49:29 -07002492{
2493 struct spi_master *master = spi->master;
Laxman Dewangane6811d12012-11-09 14:36:45 +05302494 struct spi_transfer *xfer;
Atsushi Nemoto6ea31292014-02-28 23:03:16 +09002495 int w_size;
Ernst Schwabcf32b712010-06-28 17:49:29 -07002496
Mark Brown24a00132013-07-10 15:05:40 +01002497 if (list_empty(&message->transfers))
2498 return -EINVAL;
Mark Brown24a00132013-07-10 15:05:40 +01002499
Ernst Schwabcf32b712010-06-28 17:49:29 -07002500 /* Half-duplex links include original MicroWire, and ones with
2501 * only one data pin like SPI_3WIRE (switches direction) or where
2502 * either MOSI or MISO is missing. They can also be caused by
2503 * software limitations.
2504 */
2505 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
2506 || (spi->mode & SPI_3WIRE)) {
Ernst Schwabcf32b712010-06-28 17:49:29 -07002507 unsigned flags = master->flags;
2508
2509 list_for_each_entry(xfer, &message->transfers, transfer_list) {
2510 if (xfer->rx_buf && xfer->tx_buf)
2511 return -EINVAL;
2512 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
2513 return -EINVAL;
2514 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
2515 return -EINVAL;
2516 }
2517 }
2518
Laxman Dewangane6811d12012-11-09 14:36:45 +05302519 /**
Laxman Dewangan059b8ff2013-01-05 00:17:14 +05302520 * Set transfer bits_per_word and max speed as spi device default if
2521 * it is not set for this transfer.
wangyuhangf477b7f2013-08-11 18:15:17 +08002522 * Set transfer tx_nbits and rx_nbits as single transfer default
2523 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
Laxman Dewangane6811d12012-11-09 14:36:45 +05302524 */
Martin Sperl77e80582015-11-27 12:31:09 +00002525 message->frame_length = 0;
Laxman Dewangane6811d12012-11-09 14:36:45 +05302526 list_for_each_entry(xfer, &message->transfers, transfer_list) {
Sourav Poddar078726c2013-07-18 15:31:25 +05302527 message->frame_length += xfer->len;
Laxman Dewangane6811d12012-11-09 14:36:45 +05302528 if (!xfer->bits_per_word)
2529 xfer->bits_per_word = spi->bits_per_word;
Axel Lina6f87fa2014-03-17 10:08:12 +08002530
2531 if (!xfer->speed_hz)
Laxman Dewangan059b8ff2013-01-05 00:17:14 +05302532 xfer->speed_hz = spi->max_speed_hz;
Mark Brown7dc9fbc2015-08-20 11:52:18 -07002533 if (!xfer->speed_hz)
2534 xfer->speed_hz = master->max_speed_hz;
Axel Lina6f87fa2014-03-17 10:08:12 +08002535
2536 if (master->max_speed_hz &&
2537 xfer->speed_hz > master->max_speed_hz)
2538 xfer->speed_hz = master->max_speed_hz;
Gabor Juhos56ede942013-08-14 10:25:28 +02002539
Stefan Brüns63ab6452015-08-23 16:06:30 +02002540 if (__spi_validate_bits_per_word(master, xfer->bits_per_word))
2541 return -EINVAL;
Mark Browna2fd4f92013-07-10 14:57:26 +01002542
Ivan T. Ivanov4d94bd22014-02-20 12:02:08 +02002543 /*
2544 * SPI transfer length should be multiple of SPI word size
2545 * where SPI word size should be power-of-two multiple
2546 */
2547 if (xfer->bits_per_word <= 8)
2548 w_size = 1;
2549 else if (xfer->bits_per_word <= 16)
2550 w_size = 2;
2551 else
2552 w_size = 4;
2553
Ivan T. Ivanov4d94bd22014-02-20 12:02:08 +02002554 /* No partial transfers accepted */
Atsushi Nemoto6ea31292014-02-28 23:03:16 +09002555 if (xfer->len % w_size)
Ivan T. Ivanov4d94bd22014-02-20 12:02:08 +02002556 return -EINVAL;
2557
Mark Browna2fd4f92013-07-10 14:57:26 +01002558 if (xfer->speed_hz && master->min_speed_hz &&
2559 xfer->speed_hz < master->min_speed_hz)
2560 return -EINVAL;
wangyuhangf477b7f2013-08-11 18:15:17 +08002561
2562 if (xfer->tx_buf && !xfer->tx_nbits)
2563 xfer->tx_nbits = SPI_NBITS_SINGLE;
2564 if (xfer->rx_buf && !xfer->rx_nbits)
2565 xfer->rx_nbits = SPI_NBITS_SINGLE;
2566 /* check transfer tx/rx_nbits:
Geert Uytterhoeven1afd9982014-01-12 14:00:29 +01002567 * 1. check the value matches one of single, dual and quad
2568 * 2. check tx/rx_nbits match the mode in spi_device
wangyuhangf477b7f2013-08-11 18:15:17 +08002569 */
Sourav Poddardb90a442013-08-22 21:20:48 +05302570 if (xfer->tx_buf) {
2571 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
2572 xfer->tx_nbits != SPI_NBITS_DUAL &&
2573 xfer->tx_nbits != SPI_NBITS_QUAD)
2574 return -EINVAL;
2575 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
2576 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2577 return -EINVAL;
2578 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
2579 !(spi->mode & SPI_TX_QUAD))
2580 return -EINVAL;
Sourav Poddardb90a442013-08-22 21:20:48 +05302581 }
wangyuhangf477b7f2013-08-11 18:15:17 +08002582 /* check transfer rx_nbits */
Sourav Poddardb90a442013-08-22 21:20:48 +05302583 if (xfer->rx_buf) {
2584 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
2585 xfer->rx_nbits != SPI_NBITS_DUAL &&
2586 xfer->rx_nbits != SPI_NBITS_QUAD)
2587 return -EINVAL;
2588 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
2589 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2590 return -EINVAL;
2591 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
2592 !(spi->mode & SPI_RX_QUAD))
2593 return -EINVAL;
Sourav Poddardb90a442013-08-22 21:20:48 +05302594 }
Laxman Dewangane6811d12012-11-09 14:36:45 +05302595 }
2596
Ernst Schwabcf32b712010-06-28 17:49:29 -07002597 message->status = -EINPROGRESS;
Mark Brown90808732013-11-13 23:44:15 +00002598
2599 return 0;
2600}
2601
2602static int __spi_async(struct spi_device *spi, struct spi_message *message)
2603{
2604 struct spi_master *master = spi->master;
2605
2606 message->spi = spi;
2607
Martin Sperleca2ebc2015-06-22 13:00:36 +00002608 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_async);
2609 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
2610
Mark Brown90808732013-11-13 23:44:15 +00002611 trace_spi_message_submit(message);
2612
Ernst Schwabcf32b712010-06-28 17:49:29 -07002613 return master->transfer(spi, message);
2614}
2615
David Brownell568d0692009-09-22 16:46:18 -07002616/**
2617 * spi_async - asynchronous SPI transfer
2618 * @spi: device with which data will be exchanged
2619 * @message: describes the data transfers, including completion callback
2620 * Context: any (irqs may be blocked, etc)
2621 *
2622 * This call may be used in_irq and other contexts which can't sleep,
2623 * as well as from task contexts which can sleep.
2624 *
2625 * The completion callback is invoked in a context which can't sleep.
2626 * Before that invocation, the value of message->status is undefined.
2627 * When the callback is issued, message->status holds either zero (to
2628 * indicate complete success) or a negative error code. After that
2629 * callback returns, the driver which issued the transfer request may
2630 * deallocate the associated memory; it's no longer in use by any SPI
2631 * core or controller driver code.
2632 *
2633 * Note that although all messages to a spi_device are handled in
2634 * FIFO order, messages may go to different devices in other orders.
2635 * Some device might be higher priority, or have various "hard" access
2636 * time requirements, for example.
2637 *
2638 * On detection of any fault during the transfer, processing of
2639 * the entire message is aborted, and the device is deselected.
2640 * Until returning from the associated message completion callback,
2641 * no other spi_message queued to that device will be processed.
2642 * (This rule applies equally to all the synchronous transfer calls,
2643 * which are wrappers around this core asynchronous primitive.)
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002644 *
2645 * Return: zero on success, else a negative error code.
David Brownell568d0692009-09-22 16:46:18 -07002646 */
2647int spi_async(struct spi_device *spi, struct spi_message *message)
2648{
2649 struct spi_master *master = spi->master;
Ernst Schwabcf32b712010-06-28 17:49:29 -07002650 int ret;
2651 unsigned long flags;
David Brownell568d0692009-09-22 16:46:18 -07002652
Mark Brown90808732013-11-13 23:44:15 +00002653 ret = __spi_validate(spi, message);
2654 if (ret != 0)
2655 return ret;
2656
Ernst Schwabcf32b712010-06-28 17:49:29 -07002657 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
David Brownell568d0692009-09-22 16:46:18 -07002658
Ernst Schwabcf32b712010-06-28 17:49:29 -07002659 if (master->bus_lock_flag)
2660 ret = -EBUSY;
2661 else
2662 ret = __spi_async(spi, message);
David Brownell568d0692009-09-22 16:46:18 -07002663
Ernst Schwabcf32b712010-06-28 17:49:29 -07002664 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2665
2666 return ret;
David Brownell568d0692009-09-22 16:46:18 -07002667}
2668EXPORT_SYMBOL_GPL(spi_async);
2669
Ernst Schwabcf32b712010-06-28 17:49:29 -07002670/**
2671 * spi_async_locked - version of spi_async with exclusive bus usage
2672 * @spi: device with which data will be exchanged
2673 * @message: describes the data transfers, including completion callback
2674 * Context: any (irqs may be blocked, etc)
2675 *
2676 * This call may be used in_irq and other contexts which can't sleep,
2677 * as well as from task contexts which can sleep.
2678 *
2679 * The completion callback is invoked in a context which can't sleep.
2680 * Before that invocation, the value of message->status is undefined.
2681 * When the callback is issued, message->status holds either zero (to
2682 * indicate complete success) or a negative error code. After that
2683 * callback returns, the driver which issued the transfer request may
2684 * deallocate the associated memory; it's no longer in use by any SPI
2685 * core or controller driver code.
2686 *
2687 * Note that although all messages to a spi_device are handled in
2688 * FIFO order, messages may go to different devices in other orders.
2689 * Some device might be higher priority, or have various "hard" access
2690 * time requirements, for example.
2691 *
2692 * On detection of any fault during the transfer, processing of
2693 * the entire message is aborted, and the device is deselected.
2694 * Until returning from the associated message completion callback,
2695 * no other spi_message queued to that device will be processed.
2696 * (This rule applies equally to all the synchronous transfer calls,
2697 * which are wrappers around this core asynchronous primitive.)
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002698 *
2699 * Return: zero on success, else a negative error code.
Ernst Schwabcf32b712010-06-28 17:49:29 -07002700 */
2701int spi_async_locked(struct spi_device *spi, struct spi_message *message)
2702{
2703 struct spi_master *master = spi->master;
2704 int ret;
2705 unsigned long flags;
2706
Mark Brown90808732013-11-13 23:44:15 +00002707 ret = __spi_validate(spi, message);
2708 if (ret != 0)
2709 return ret;
2710
Ernst Schwabcf32b712010-06-28 17:49:29 -07002711 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2712
2713 ret = __spi_async(spi, message);
2714
2715 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2716
2717 return ret;
2718
2719}
2720EXPORT_SYMBOL_GPL(spi_async_locked);
2721
David Brownell7d077192009-06-17 16:26:03 -07002722
Vignesh R556351f2015-12-11 09:39:56 +05302723int spi_flash_read(struct spi_device *spi,
2724 struct spi_flash_read_message *msg)
2725
2726{
2727 struct spi_master *master = spi->master;
2728 int ret;
2729
2730 if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
2731 msg->addr_nbits == SPI_NBITS_DUAL) &&
2732 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
2733 return -EINVAL;
2734 if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
2735 msg->addr_nbits == SPI_NBITS_QUAD) &&
2736 !(spi->mode & SPI_TX_QUAD))
2737 return -EINVAL;
2738 if (msg->data_nbits == SPI_NBITS_DUAL &&
2739 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
2740 return -EINVAL;
2741 if (msg->data_nbits == SPI_NBITS_QUAD &&
2742 !(spi->mode & SPI_RX_QUAD))
2743 return -EINVAL;
2744
2745 if (master->auto_runtime_pm) {
2746 ret = pm_runtime_get_sync(master->dev.parent);
2747 if (ret < 0) {
2748 dev_err(&master->dev, "Failed to power device: %d\n",
2749 ret);
2750 return ret;
2751 }
2752 }
2753 mutex_lock(&master->bus_lock_mutex);
2754 ret = master->spi_flash_read(spi, msg);
2755 mutex_unlock(&master->bus_lock_mutex);
2756 if (master->auto_runtime_pm)
2757 pm_runtime_put(master->dev.parent);
2758
2759 return ret;
2760}
2761EXPORT_SYMBOL_GPL(spi_flash_read);
2762
David Brownell7d077192009-06-17 16:26:03 -07002763/*-------------------------------------------------------------------------*/
2764
2765/* Utility methods for SPI master protocol drivers, layered on
2766 * top of the core. Some other utility methods are defined as
2767 * inline functions.
2768 */
2769
Andrew Morton5d870c82006-01-11 11:23:49 -08002770static void spi_complete(void *arg)
2771{
2772 complete(arg);
2773}
2774
Ernst Schwabcf32b712010-06-28 17:49:29 -07002775static int __spi_sync(struct spi_device *spi, struct spi_message *message,
2776 int bus_locked)
2777{
2778 DECLARE_COMPLETION_ONSTACK(done);
2779 int status;
2780 struct spi_master *master = spi->master;
Mark Brown0461a412014-12-09 21:38:05 +00002781 unsigned long flags;
2782
2783 status = __spi_validate(spi, message);
2784 if (status != 0)
2785 return status;
Ernst Schwabcf32b712010-06-28 17:49:29 -07002786
2787 message->complete = spi_complete;
2788 message->context = &done;
Mark Brown0461a412014-12-09 21:38:05 +00002789 message->spi = spi;
Ernst Schwabcf32b712010-06-28 17:49:29 -07002790
Martin Sperleca2ebc2015-06-22 13:00:36 +00002791 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
2792 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
2793
Ernst Schwabcf32b712010-06-28 17:49:29 -07002794 if (!bus_locked)
2795 mutex_lock(&master->bus_lock_mutex);
2796
Mark Brown0461a412014-12-09 21:38:05 +00002797 /* If we're not using the legacy transfer method then we will
2798 * try to transfer in the calling context so special case.
2799 * This code would be less tricky if we could remove the
2800 * support for driver implemented message queues.
2801 */
2802 if (master->transfer == spi_queued_transfer) {
2803 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2804
2805 trace_spi_message_submit(message);
2806
2807 status = __spi_queued_transfer(spi, message, false);
2808
2809 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2810 } else {
2811 status = spi_async_locked(spi, message);
2812 }
Ernst Schwabcf32b712010-06-28 17:49:29 -07002813
2814 if (!bus_locked)
2815 mutex_unlock(&master->bus_lock_mutex);
2816
2817 if (status == 0) {
Mark Brown0461a412014-12-09 21:38:05 +00002818 /* Push out the messages in the calling context if we
2819 * can.
2820 */
Martin Sperleca2ebc2015-06-22 13:00:36 +00002821 if (master->transfer == spi_queued_transfer) {
2822 SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
2823 spi_sync_immediate);
2824 SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
2825 spi_sync_immediate);
Jon Hunter49023d22016-03-08 12:28:20 +00002826 __spi_pump_messages(master, false, bus_locked);
Martin Sperleca2ebc2015-06-22 13:00:36 +00002827 }
Mark Brown0461a412014-12-09 21:38:05 +00002828
Ernst Schwabcf32b712010-06-28 17:49:29 -07002829 wait_for_completion(&done);
2830 status = message->status;
2831 }
2832 message->context = NULL;
2833 return status;
2834}
2835
David Brownell8ae12a02006-01-08 13:34:19 -08002836/**
2837 * spi_sync - blocking/synchronous SPI data transfers
2838 * @spi: device with which data will be exchanged
2839 * @message: describes the data transfers
David Brownell33e34dc2007-05-08 00:32:21 -07002840 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08002841 *
2842 * This call may only be used from a context that may sleep. The sleep
2843 * is non-interruptible, and has no timeout. Low-overhead controller
2844 * drivers may DMA directly into and out of the message buffers.
2845 *
2846 * Note that the SPI device's chip select is active during the message,
2847 * and then is normally disabled between messages. Drivers for some
2848 * frequently-used devices may want to minimize costs of selecting a chip,
2849 * by leaving it selected in anticipation that the next message will go
2850 * to the same chip. (That may increase power usage.)
2851 *
David Brownell0c868462006-01-08 13:34:25 -08002852 * Also, the caller is guaranteeing that the memory associated with the
2853 * message will not be freed before this call returns.
2854 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002855 * Return: zero on success, else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08002856 */
2857int spi_sync(struct spi_device *spi, struct spi_message *message)
2858{
Heiko Stübner24c8cd12016-03-18 11:15:11 +01002859 return __spi_sync(spi, message, spi->master->bus_lock_flag);
David Brownell8ae12a02006-01-08 13:34:19 -08002860}
2861EXPORT_SYMBOL_GPL(spi_sync);
2862
Ernst Schwabcf32b712010-06-28 17:49:29 -07002863/**
2864 * spi_sync_locked - version of spi_sync with exclusive bus usage
2865 * @spi: device with which data will be exchanged
2866 * @message: describes the data transfers
2867 * Context: can sleep
2868 *
2869 * This call may only be used from a context that may sleep. The sleep
2870 * is non-interruptible, and has no timeout. Low-overhead controller
2871 * drivers may DMA directly into and out of the message buffers.
2872 *
2873 * This call should be used by drivers that require exclusive access to the
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002874 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
Ernst Schwabcf32b712010-06-28 17:49:29 -07002875 * be released by a spi_bus_unlock call when the exclusive access is over.
2876 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002877 * Return: zero on success, else a negative error code.
Ernst Schwabcf32b712010-06-28 17:49:29 -07002878 */
2879int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
2880{
2881 return __spi_sync(spi, message, 1);
2882}
2883EXPORT_SYMBOL_GPL(spi_sync_locked);
2884
2885/**
2886 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
2887 * @master: SPI bus master that should be locked for exclusive bus access
2888 * Context: can sleep
2889 *
2890 * This call may only be used from a context that may sleep. The sleep
2891 * is non-interruptible, and has no timeout.
2892 *
2893 * This call should be used by drivers that require exclusive access to the
2894 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
2895 * exclusive access is over. Data transfer must be done by spi_sync_locked
2896 * and spi_async_locked calls when the SPI bus lock is held.
2897 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002898 * Return: always zero.
Ernst Schwabcf32b712010-06-28 17:49:29 -07002899 */
2900int spi_bus_lock(struct spi_master *master)
2901{
2902 unsigned long flags;
2903
2904 mutex_lock(&master->bus_lock_mutex);
2905
2906 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
2907 master->bus_lock_flag = 1;
2908 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
2909
2910 /* mutex remains locked until spi_bus_unlock is called */
2911
2912 return 0;
2913}
2914EXPORT_SYMBOL_GPL(spi_bus_lock);
2915
2916/**
2917 * spi_bus_unlock - release the lock for exclusive SPI bus usage
2918 * @master: SPI bus master that was locked for exclusive bus access
2919 * Context: can sleep
2920 *
2921 * This call may only be used from a context that may sleep. The sleep
2922 * is non-interruptible, and has no timeout.
2923 *
2924 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
2925 * call.
2926 *
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002927 * Return: always zero.
Ernst Schwabcf32b712010-06-28 17:49:29 -07002928 */
2929int spi_bus_unlock(struct spi_master *master)
2930{
2931 master->bus_lock_flag = 0;
2932
2933 mutex_unlock(&master->bus_lock_mutex);
2934
2935 return 0;
2936}
2937EXPORT_SYMBOL_GPL(spi_bus_unlock);
2938
David Brownella9948b62006-04-02 10:37:40 -08002939/* portable code must never pass more than 32 bytes */
Jingoo Han5fe5f052013-10-14 10:31:51 +09002940#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
David Brownell8ae12a02006-01-08 13:34:19 -08002941
2942static u8 *buf;
2943
2944/**
2945 * spi_write_then_read - SPI synchronous write followed by read
2946 * @spi: device with which data will be exchanged
2947 * @txbuf: data to be written (need not be dma-safe)
2948 * @n_tx: size of txbuf, in bytes
Jiri Pirko27570492009-06-17 16:26:06 -07002949 * @rxbuf: buffer into which data will be read (need not be dma-safe)
2950 * @n_rx: size of rxbuf, in bytes
David Brownell33e34dc2007-05-08 00:32:21 -07002951 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08002952 *
2953 * This performs a half duplex MicroWire style transaction with the
2954 * device, sending txbuf and then reading rxbuf. The return value
2955 * is zero for success, else a negative errno status code.
David Brownellb8852442006-01-08 13:34:23 -08002956 * This call may only be used from a context that may sleep.
David Brownell8ae12a02006-01-08 13:34:19 -08002957 *
David Brownell0c868462006-01-08 13:34:25 -08002958 * Parameters to this routine are always copied using a small buffer;
David Brownell33e34dc2007-05-08 00:32:21 -07002959 * portable code should never use this for more than 32 bytes.
2960 * Performance-sensitive or bulk transfer code should instead use
David Brownell0c868462006-01-08 13:34:25 -08002961 * spi_{async,sync}() calls with dma-safe buffers.
Javier Martinez Canillas97d56dc2015-10-22 18:59:23 +02002962 *
2963 * Return: zero on success, else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08002964 */
2965int spi_write_then_read(struct spi_device *spi,
Mark Brown0c4a1592011-05-11 00:09:30 +02002966 const void *txbuf, unsigned n_tx,
2967 void *rxbuf, unsigned n_rx)
David Brownell8ae12a02006-01-08 13:34:19 -08002968{
David Brownell068f4072007-12-04 23:45:09 -08002969 static DEFINE_MUTEX(lock);
David Brownell8ae12a02006-01-08 13:34:19 -08002970
2971 int status;
2972 struct spi_message message;
David Brownellbdff5492009-04-13 14:39:57 -07002973 struct spi_transfer x[2];
David Brownell8ae12a02006-01-08 13:34:19 -08002974 u8 *local_buf;
2975
Mark Brownb3a223e2012-12-02 12:54:25 +09002976 /* Use preallocated DMA-safe buffer if we can. We can't avoid
2977 * copying here, (as a pure convenience thing), but we can
2978 * keep heap costs out of the hot path unless someone else is
2979 * using the pre-allocated buffer or the transfer is too large.
David Brownell8ae12a02006-01-08 13:34:19 -08002980 */
Mark Brownb3a223e2012-12-02 12:54:25 +09002981 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
Mark Brown2cd94c82013-01-27 14:35:04 +08002982 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
2983 GFP_KERNEL | GFP_DMA);
Mark Brownb3a223e2012-12-02 12:54:25 +09002984 if (!local_buf)
2985 return -ENOMEM;
2986 } else {
2987 local_buf = buf;
2988 }
David Brownell8ae12a02006-01-08 13:34:19 -08002989
Vitaly Wool8275c642006-01-08 13:34:28 -08002990 spi_message_init(&message);
Jingoo Han5fe5f052013-10-14 10:31:51 +09002991 memset(x, 0, sizeof(x));
David Brownellbdff5492009-04-13 14:39:57 -07002992 if (n_tx) {
2993 x[0].len = n_tx;
2994 spi_message_add_tail(&x[0], &message);
2995 }
2996 if (n_rx) {
2997 x[1].len = n_rx;
2998 spi_message_add_tail(&x[1], &message);
2999 }
Vitaly Wool8275c642006-01-08 13:34:28 -08003000
David Brownell8ae12a02006-01-08 13:34:19 -08003001 memcpy(local_buf, txbuf, n_tx);
David Brownellbdff5492009-04-13 14:39:57 -07003002 x[0].tx_buf = local_buf;
3003 x[1].rx_buf = local_buf + n_tx;
David Brownell8ae12a02006-01-08 13:34:19 -08003004
3005 /* do the i/o */
David Brownell8ae12a02006-01-08 13:34:19 -08003006 status = spi_sync(spi, &message);
Marc Pignat9b938b72007-12-04 23:45:10 -08003007 if (status == 0)
David Brownellbdff5492009-04-13 14:39:57 -07003008 memcpy(rxbuf, x[1].rx_buf, n_rx);
David Brownell8ae12a02006-01-08 13:34:19 -08003009
David Brownellbdff5492009-04-13 14:39:57 -07003010 if (x[0].tx_buf == buf)
David Brownell068f4072007-12-04 23:45:09 -08003011 mutex_unlock(&lock);
David Brownell8ae12a02006-01-08 13:34:19 -08003012 else
3013 kfree(local_buf);
3014
3015 return status;
3016}
3017EXPORT_SYMBOL_GPL(spi_write_then_read);
3018
3019/*-------------------------------------------------------------------------*/
3020
Pantelis Antoniouce79d542014-10-28 22:36:05 +02003021#if IS_ENABLED(CONFIG_OF_DYNAMIC)
3022static int __spi_of_device_match(struct device *dev, void *data)
3023{
3024 return dev->of_node == data;
3025}
3026
3027/* must call put_device() when done with returned spi_device device */
3028static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
3029{
3030 struct device *dev = bus_find_device(&spi_bus_type, NULL, node,
3031 __spi_of_device_match);
3032 return dev ? to_spi_device(dev) : NULL;
3033}
3034
3035static int __spi_of_master_match(struct device *dev, const void *data)
3036{
3037 return dev->of_node == data;
3038}
3039
3040/* the spi masters are not using spi_bus, so we find it with another way */
3041static struct spi_master *of_find_spi_master_by_node(struct device_node *node)
3042{
3043 struct device *dev;
3044
3045 dev = class_find_device(&spi_master_class, NULL, node,
3046 __spi_of_master_match);
3047 if (!dev)
3048 return NULL;
3049
3050 /* reference got in class_find_device */
3051 return container_of(dev, struct spi_master, dev);
3052}
3053
3054static int of_spi_notify(struct notifier_block *nb, unsigned long action,
3055 void *arg)
3056{
3057 struct of_reconfig_data *rd = arg;
3058 struct spi_master *master;
3059 struct spi_device *spi;
3060
3061 switch (of_reconfig_get_state_change(action, arg)) {
3062 case OF_RECONFIG_CHANGE_ADD:
3063 master = of_find_spi_master_by_node(rd->dn->parent);
3064 if (master == NULL)
3065 return NOTIFY_OK; /* not for us */
3066
Geert Uytterhoevenbd6c1642015-11-30 15:28:07 +01003067 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
3068 put_device(&master->dev);
3069 return NOTIFY_OK;
3070 }
3071
Pantelis Antoniouce79d542014-10-28 22:36:05 +02003072 spi = of_register_spi_device(master, rd->dn);
3073 put_device(&master->dev);
3074
3075 if (IS_ERR(spi)) {
3076 pr_err("%s: failed to create for '%s'\n",
3077 __func__, rd->dn->full_name);
3078 return notifier_from_errno(PTR_ERR(spi));
3079 }
3080 break;
3081
3082 case OF_RECONFIG_CHANGE_REMOVE:
Geert Uytterhoevenbd6c1642015-11-30 15:28:07 +01003083 /* already depopulated? */
3084 if (!of_node_check_flag(rd->dn, OF_POPULATED))
3085 return NOTIFY_OK;
3086
Pantelis Antoniouce79d542014-10-28 22:36:05 +02003087 /* find our device by node */
3088 spi = of_find_spi_device_by_node(rd->dn);
3089 if (spi == NULL)
3090 return NOTIFY_OK; /* no? not meant for us */
3091
3092 /* unregister takes one ref away */
3093 spi_unregister_device(spi);
3094
3095 /* and put the reference of the find */
3096 put_device(&spi->dev);
3097 break;
3098 }
3099
3100 return NOTIFY_OK;
3101}
3102
3103static struct notifier_block spi_of_notifier = {
3104 .notifier_call = of_spi_notify,
3105};
3106#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3107extern struct notifier_block spi_of_notifier;
3108#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
3109
David Brownell8ae12a02006-01-08 13:34:19 -08003110static int __init spi_init(void)
3111{
David Brownellb8852442006-01-08 13:34:23 -08003112 int status;
David Brownell8ae12a02006-01-08 13:34:19 -08003113
Christoph Lametere94b1762006-12-06 20:33:17 -08003114 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
David Brownellb8852442006-01-08 13:34:23 -08003115 if (!buf) {
3116 status = -ENOMEM;
3117 goto err0;
3118 }
3119
3120 status = bus_register(&spi_bus_type);
3121 if (status < 0)
3122 goto err1;
3123
3124 status = class_register(&spi_master_class);
3125 if (status < 0)
3126 goto err2;
Pantelis Antoniouce79d542014-10-28 22:36:05 +02003127
Fabio Estevam52677202014-11-26 20:13:57 -02003128 if (IS_ENABLED(CONFIG_OF_DYNAMIC))
Pantelis Antoniouce79d542014-10-28 22:36:05 +02003129 WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
3130
David Brownell8ae12a02006-01-08 13:34:19 -08003131 return 0;
David Brownellb8852442006-01-08 13:34:23 -08003132
3133err2:
3134 bus_unregister(&spi_bus_type);
3135err1:
3136 kfree(buf);
3137 buf = NULL;
3138err0:
3139 return status;
David Brownell8ae12a02006-01-08 13:34:19 -08003140}
David Brownellb8852442006-01-08 13:34:23 -08003141
David Brownell8ae12a02006-01-08 13:34:19 -08003142/* board_info is normally registered in arch_initcall(),
3143 * but even essential drivers wait till later
David Brownellb8852442006-01-08 13:34:23 -08003144 *
3145 * REVISIT only boardinfo really needs static linking. the rest (device and
3146 * driver registration) _could_ be dynamically linked (modular) ... costs
3147 * include needing to have boardinfo data structures be much more public.
David Brownell8ae12a02006-01-08 13:34:19 -08003148 */
David Brownell673c0c02008-10-15 22:02:46 -07003149postcore_initcall(spi_init);
David Brownell8ae12a02006-01-08 13:34:19 -08003150