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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.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
David Brownell8ae12a02006-01-08 13:34:19 -080022#include <linux/kernel.h>
Grant Likelyd57a4282012-04-07 14:16:53 -060023#include <linux/kmod.h>
David Brownell8ae12a02006-01-08 13:34:19 -080024#include <linux/device.h>
25#include <linux/init.h>
26#include <linux/cache.h>
Matthias Kaehlcke94040822007-07-17 04:04:16 -070027#include <linux/mutex.h>
Sinan Akman2b7a32f2010-10-02 21:28:29 -060028#include <linux/of_device.h>
Grant Likelyd57a4282012-04-07 14:16:53 -060029#include <linux/of_irq.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Anton Vorontsove0626e32009-09-22 16:46:08 -070031#include <linux/mod_devicetable.h>
David Brownell8ae12a02006-01-08 13:34:19 -080032#include <linux/spi/spi.h>
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +010033#include <linux/of_gpio.h>
Mark Brown3ae22e82010-12-25 15:32:27 +010034#include <linux/pm_runtime.h>
Paul Gortmaker025ed132011-07-10 12:57:55 -040035#include <linux/export.h>
Clark Williams8bd75c72013-02-07 09:47:07 -060036#include <linux/sched/rt.h>
Linus Walleijffbbdd212012-02-22 10:05:38 +010037#include <linux/delay.h>
38#include <linux/kthread.h>
Mika Westerberg64bee4d2012-11-30 12:37:53 +010039#include <linux/ioport.h>
40#include <linux/acpi.h>
David Brownell8ae12a02006-01-08 13:34:19 -080041
Mark Brown56ec1972013-10-07 19:33:53 +010042#define CREATE_TRACE_POINTS
43#include <trace/events/spi.h>
44
David Brownell8ae12a02006-01-08 13:34:19 -080045static void spidev_release(struct device *dev)
46{
Hans-Peter Nilsson0ffa0282007-02-12 00:52:45 -080047 struct spi_device *spi = to_spi_device(dev);
David Brownell8ae12a02006-01-08 13:34:19 -080048
49 /* spi masters may cleanup for released devices */
50 if (spi->master->cleanup)
51 spi->master->cleanup(spi);
52
David Brownell0c868462006-01-08 13:34:25 -080053 spi_master_put(spi->master);
Roman Tereshonkov07a389f2010-04-12 09:56:35 +000054 kfree(spi);
David Brownell8ae12a02006-01-08 13:34:19 -080055}
56
57static ssize_t
58modalias_show(struct device *dev, struct device_attribute *a, char *buf)
59{
60 const struct spi_device *spi = to_spi_device(dev);
61
Grant Likelyd8e328b2012-05-20 00:08:13 -060062 return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
David Brownell8ae12a02006-01-08 13:34:19 -080063}
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -070064static DEVICE_ATTR_RO(modalias);
David Brownell8ae12a02006-01-08 13:34:19 -080065
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -070066static struct attribute *spi_dev_attrs[] = {
67 &dev_attr_modalias.attr,
68 NULL,
David Brownell8ae12a02006-01-08 13:34:19 -080069};
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -070070ATTRIBUTE_GROUPS(spi_dev);
David Brownell8ae12a02006-01-08 13:34:19 -080071
72/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
73 * and the sysfs version makes coldplug work too.
74 */
75
Anton Vorontsov75368bf2009-09-22 16:46:04 -070076static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
77 const struct spi_device *sdev)
78{
79 while (id->name[0]) {
80 if (!strcmp(sdev->modalias, id->name))
81 return id;
82 id++;
83 }
84 return NULL;
85}
86
87const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
88{
89 const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
90
91 return spi_match_id(sdrv->id_table, sdev);
92}
93EXPORT_SYMBOL_GPL(spi_get_device_id);
94
David Brownell8ae12a02006-01-08 13:34:19 -080095static int spi_match_device(struct device *dev, struct device_driver *drv)
96{
97 const struct spi_device *spi = to_spi_device(dev);
Anton Vorontsov75368bf2009-09-22 16:46:04 -070098 const struct spi_driver *sdrv = to_spi_driver(drv);
99
Sinan Akman2b7a32f2010-10-02 21:28:29 -0600100 /* Attempt an OF style match */
101 if (of_driver_match_device(dev, drv))
102 return 1;
103
Mika Westerberg64bee4d2012-11-30 12:37:53 +0100104 /* Then try ACPI */
105 if (acpi_driver_match_device(dev, drv))
106 return 1;
107
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700108 if (sdrv->id_table)
109 return !!spi_match_id(sdrv->id_table, spi);
David Brownell8ae12a02006-01-08 13:34:19 -0800110
Kay Sievers35f74fc2009-01-06 10:44:37 -0800111 return strcmp(spi->modalias, drv->name) == 0;
David Brownell8ae12a02006-01-08 13:34:19 -0800112}
113
Kay Sievers7eff2e72007-08-14 15:15:12 +0200114static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
David Brownell8ae12a02006-01-08 13:34:19 -0800115{
116 const struct spi_device *spi = to_spi_device(dev);
117
Anton Vorontsove0626e32009-09-22 16:46:08 -0700118 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
David Brownell8ae12a02006-01-08 13:34:19 -0800119 return 0;
120}
121
Mark Brown3ae22e82010-12-25 15:32:27 +0100122#ifdef CONFIG_PM_SLEEP
123static int spi_legacy_suspend(struct device *dev, pm_message_t message)
David Brownell8ae12a02006-01-08 13:34:19 -0800124{
David Brownell3c724262008-02-06 01:38:10 -0800125 int value = 0;
David Brownellb8852442006-01-08 13:34:23 -0800126 struct spi_driver *drv = to_spi_driver(dev->driver);
David Brownell8ae12a02006-01-08 13:34:19 -0800127
David Brownell8ae12a02006-01-08 13:34:19 -0800128 /* suspend will stop irqs and dma; no more i/o */
David Brownell3c724262008-02-06 01:38:10 -0800129 if (drv) {
130 if (drv->suspend)
131 value = drv->suspend(to_spi_device(dev), message);
132 else
133 dev_dbg(dev, "... can't suspend\n");
134 }
David Brownell8ae12a02006-01-08 13:34:19 -0800135 return value;
136}
137
Mark Brown3ae22e82010-12-25 15:32:27 +0100138static int spi_legacy_resume(struct device *dev)
David Brownell8ae12a02006-01-08 13:34:19 -0800139{
David Brownell3c724262008-02-06 01:38:10 -0800140 int value = 0;
David Brownellb8852442006-01-08 13:34:23 -0800141 struct spi_driver *drv = to_spi_driver(dev->driver);
David Brownell8ae12a02006-01-08 13:34:19 -0800142
David Brownell8ae12a02006-01-08 13:34:19 -0800143 /* resume may restart the i/o queue */
David Brownell3c724262008-02-06 01:38:10 -0800144 if (drv) {
145 if (drv->resume)
146 value = drv->resume(to_spi_device(dev));
147 else
148 dev_dbg(dev, "... can't resume\n");
149 }
David Brownell8ae12a02006-01-08 13:34:19 -0800150 return value;
151}
152
Mark Brown3ae22e82010-12-25 15:32:27 +0100153static int spi_pm_suspend(struct device *dev)
154{
155 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
156
157 if (pm)
158 return pm_generic_suspend(dev);
159 else
160 return spi_legacy_suspend(dev, PMSG_SUSPEND);
161}
162
163static int spi_pm_resume(struct device *dev)
164{
165 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
166
167 if (pm)
168 return pm_generic_resume(dev);
169 else
170 return spi_legacy_resume(dev);
171}
172
173static int spi_pm_freeze(struct device *dev)
174{
175 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
176
177 if (pm)
178 return pm_generic_freeze(dev);
179 else
180 return spi_legacy_suspend(dev, PMSG_FREEZE);
181}
182
183static int spi_pm_thaw(struct device *dev)
184{
185 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
186
187 if (pm)
188 return pm_generic_thaw(dev);
189 else
190 return spi_legacy_resume(dev);
191}
192
193static int spi_pm_poweroff(struct device *dev)
194{
195 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
196
197 if (pm)
198 return pm_generic_poweroff(dev);
199 else
200 return spi_legacy_suspend(dev, PMSG_HIBERNATE);
201}
202
203static int spi_pm_restore(struct device *dev)
204{
205 const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
206
207 if (pm)
208 return pm_generic_restore(dev);
209 else
210 return spi_legacy_resume(dev);
211}
David Brownell8ae12a02006-01-08 13:34:19 -0800212#else
Mark Brown3ae22e82010-12-25 15:32:27 +0100213#define spi_pm_suspend NULL
214#define spi_pm_resume NULL
215#define spi_pm_freeze NULL
216#define spi_pm_thaw NULL
217#define spi_pm_poweroff NULL
218#define spi_pm_restore NULL
David Brownell8ae12a02006-01-08 13:34:19 -0800219#endif
220
Mark Brown3ae22e82010-12-25 15:32:27 +0100221static const struct dev_pm_ops spi_pm = {
222 .suspend = spi_pm_suspend,
223 .resume = spi_pm_resume,
224 .freeze = spi_pm_freeze,
225 .thaw = spi_pm_thaw,
226 .poweroff = spi_pm_poweroff,
227 .restore = spi_pm_restore,
228 SET_RUNTIME_PM_OPS(
229 pm_generic_runtime_suspend,
230 pm_generic_runtime_resume,
Rafael J. Wysocki45f0a852013-06-03 21:49:52 +0200231 NULL
Mark Brown3ae22e82010-12-25 15:32:27 +0100232 )
233};
234
David Brownell8ae12a02006-01-08 13:34:19 -0800235struct bus_type spi_bus_type = {
236 .name = "spi",
Greg Kroah-Hartmanaa7da562013-10-07 18:27:38 -0700237 .dev_groups = spi_dev_groups,
David Brownell8ae12a02006-01-08 13:34:19 -0800238 .match = spi_match_device,
239 .uevent = spi_uevent,
Mark Brown3ae22e82010-12-25 15:32:27 +0100240 .pm = &spi_pm,
David Brownell8ae12a02006-01-08 13:34:19 -0800241};
242EXPORT_SYMBOL_GPL(spi_bus_type);
243
David Brownellb8852442006-01-08 13:34:23 -0800244
245static int spi_drv_probe(struct device *dev)
246{
247 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300248 struct spi_device *spi = to_spi_device(dev);
249 int ret;
David Brownellb8852442006-01-08 13:34:23 -0800250
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300251 acpi_dev_pm_attach(&spi->dev, true);
252 ret = sdrv->probe(spi);
253 if (ret)
254 acpi_dev_pm_detach(&spi->dev, true);
255
256 return ret;
David Brownellb8852442006-01-08 13:34:23 -0800257}
258
259static int spi_drv_remove(struct device *dev)
260{
261 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300262 struct spi_device *spi = to_spi_device(dev);
263 int ret;
David Brownellb8852442006-01-08 13:34:23 -0800264
Mika Westerberg33cf00e2013-10-10 13:28:48 +0300265 ret = sdrv->remove(spi);
266 acpi_dev_pm_detach(&spi->dev, true);
267
268 return ret;
David Brownellb8852442006-01-08 13:34:23 -0800269}
270
271static void spi_drv_shutdown(struct device *dev)
272{
273 const struct spi_driver *sdrv = to_spi_driver(dev->driver);
274
275 sdrv->shutdown(to_spi_device(dev));
276}
277
David Brownell33e34dc2007-05-08 00:32:21 -0700278/**
279 * spi_register_driver - register a SPI driver
280 * @sdrv: the driver to register
281 * Context: can sleep
282 */
David Brownellb8852442006-01-08 13:34:23 -0800283int spi_register_driver(struct spi_driver *sdrv)
284{
285 sdrv->driver.bus = &spi_bus_type;
286 if (sdrv->probe)
287 sdrv->driver.probe = spi_drv_probe;
288 if (sdrv->remove)
289 sdrv->driver.remove = spi_drv_remove;
290 if (sdrv->shutdown)
291 sdrv->driver.shutdown = spi_drv_shutdown;
292 return driver_register(&sdrv->driver);
293}
294EXPORT_SYMBOL_GPL(spi_register_driver);
295
David Brownell8ae12a02006-01-08 13:34:19 -0800296/*-------------------------------------------------------------------------*/
297
298/* SPI devices should normally not be created by SPI device drivers; that
299 * would make them board-specific. Similarly with SPI master drivers.
300 * Device registration normally goes into like arch/.../mach.../board-YYY.c
301 * with other readonly (flashable) information about mainboard devices.
302 */
303
304struct boardinfo {
305 struct list_head list;
Feng Tang2b9603a2010-08-02 15:52:15 +0800306 struct spi_board_info board_info;
David Brownell8ae12a02006-01-08 13:34:19 -0800307};
308
309static LIST_HEAD(board_list);
Feng Tang2b9603a2010-08-02 15:52:15 +0800310static LIST_HEAD(spi_master_list);
311
312/*
313 * Used to protect add/del opertion for board_info list and
314 * spi_master list, and their matching process
315 */
Matthias Kaehlcke94040822007-07-17 04:04:16 -0700316static DEFINE_MUTEX(board_lock);
David Brownell8ae12a02006-01-08 13:34:19 -0800317
Grant Likelydc87c982008-05-15 16:50:22 -0600318/**
319 * spi_alloc_device - Allocate a new SPI device
320 * @master: Controller to which device is connected
321 * Context: can sleep
322 *
323 * Allows a driver to allocate and initialize a spi_device without
324 * registering it immediately. This allows a driver to directly
325 * fill the spi_device with device parameters before calling
326 * spi_add_device() on it.
327 *
328 * Caller is responsible to call spi_add_device() on the returned
329 * spi_device structure to add it to the SPI master. If the caller
330 * needs to discard the spi_device without adding it, then it should
331 * call spi_dev_put() on it.
332 *
333 * Returns a pointer to the new device, or NULL.
334 */
335struct spi_device *spi_alloc_device(struct spi_master *master)
336{
337 struct spi_device *spi;
338 struct device *dev = master->dev.parent;
339
340 if (!spi_master_get(master))
341 return NULL;
342
Jingoo Han5fe5f052013-10-14 10:31:51 +0900343 spi = kzalloc(sizeof(*spi), GFP_KERNEL);
Grant Likelydc87c982008-05-15 16:50:22 -0600344 if (!spi) {
345 dev_err(dev, "cannot alloc spi_device\n");
346 spi_master_put(master);
347 return NULL;
348 }
349
350 spi->master = master;
Laurent Pinchart178db7d2011-12-12 01:15:06 +0100351 spi->dev.parent = &master->dev;
Grant Likelydc87c982008-05-15 16:50:22 -0600352 spi->dev.bus = &spi_bus_type;
353 spi->dev.release = spidev_release;
Andreas Larsson446411e2013-02-13 14:20:25 +0100354 spi->cs_gpio = -ENOENT;
Grant Likelydc87c982008-05-15 16:50:22 -0600355 device_initialize(&spi->dev);
356 return spi;
357}
358EXPORT_SYMBOL_GPL(spi_alloc_device);
359
Jarkko Nikulae13ac472013-11-14 14:03:53 +0200360static void spi_dev_set_name(struct spi_device *spi)
361{
362 struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
363
364 if (adev) {
365 dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
366 return;
367 }
368
369 dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),
370 spi->chip_select);
371}
372
Grant Likelydc87c982008-05-15 16:50:22 -0600373/**
374 * spi_add_device - Add spi_device allocated with spi_alloc_device
375 * @spi: spi_device to register
376 *
377 * Companion function to spi_alloc_device. Devices allocated with
378 * spi_alloc_device can be added onto the spi bus with this function.
379 *
David Brownelle48880e2008-08-15 00:40:44 -0700380 * Returns 0 on success; negative errno on failure
Grant Likelydc87c982008-05-15 16:50:22 -0600381 */
382int spi_add_device(struct spi_device *spi)
383{
David Brownelle48880e2008-08-15 00:40:44 -0700384 static DEFINE_MUTEX(spi_add_lock);
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100385 struct spi_master *master = spi->master;
386 struct device *dev = master->dev.parent;
Roman Tereshonkov8ec130a2010-04-16 09:52:59 +0000387 struct device *d;
Grant Likelydc87c982008-05-15 16:50:22 -0600388 int status;
389
390 /* Chipselects are numbered 0..max; validate. */
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100391 if (spi->chip_select >= master->num_chipselect) {
Grant Likelydc87c982008-05-15 16:50:22 -0600392 dev_err(dev, "cs%d >= max %d\n",
393 spi->chip_select,
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100394 master->num_chipselect);
Grant Likelydc87c982008-05-15 16:50:22 -0600395 return -EINVAL;
396 }
397
398 /* Set the bus ID string */
Jarkko Nikulae13ac472013-11-14 14:03:53 +0200399 spi_dev_set_name(spi);
David Brownelle48880e2008-08-15 00:40:44 -0700400
401 /* We need to make sure there's no other device with this
402 * chipselect **BEFORE** we call setup(), else we'll trash
403 * its configuration. Lock against concurrent add() calls.
404 */
405 mutex_lock(&spi_add_lock);
406
Roman Tereshonkov8ec130a2010-04-16 09:52:59 +0000407 d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
408 if (d != NULL) {
David Brownelle48880e2008-08-15 00:40:44 -0700409 dev_err(dev, "chipselect %d already in use\n",
410 spi->chip_select);
Roman Tereshonkov8ec130a2010-04-16 09:52:59 +0000411 put_device(d);
David Brownelle48880e2008-08-15 00:40:44 -0700412 status = -EBUSY;
413 goto done;
414 }
415
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100416 if (master->cs_gpios)
417 spi->cs_gpio = master->cs_gpios[spi->chip_select];
418
David Brownelle48880e2008-08-15 00:40:44 -0700419 /* Drivers may modify this initial i/o setup, but will
420 * normally rely on the device being setup. Devices
421 * using SPI_CS_HIGH can't coexist well otherwise...
422 */
David Brownell7d077192009-06-17 16:26:03 -0700423 status = spi_setup(spi);
Grant Likelydc87c982008-05-15 16:50:22 -0600424 if (status < 0) {
Linus Walleijeb288a12010-10-21 21:06:44 +0200425 dev_err(dev, "can't setup %s, status %d\n",
426 dev_name(&spi->dev), status);
David Brownelle48880e2008-08-15 00:40:44 -0700427 goto done;
Grant Likelydc87c982008-05-15 16:50:22 -0600428 }
429
David Brownelle48880e2008-08-15 00:40:44 -0700430 /* Device may be bound to an active driver when this returns */
Grant Likelydc87c982008-05-15 16:50:22 -0600431 status = device_add(&spi->dev);
David Brownelle48880e2008-08-15 00:40:44 -0700432 if (status < 0)
Linus Walleijeb288a12010-10-21 21:06:44 +0200433 dev_err(dev, "can't add %s, status %d\n",
434 dev_name(&spi->dev), status);
David Brownelle48880e2008-08-15 00:40:44 -0700435 else
Kay Sievers35f74fc2009-01-06 10:44:37 -0800436 dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
Grant Likelydc87c982008-05-15 16:50:22 -0600437
David Brownelle48880e2008-08-15 00:40:44 -0700438done:
439 mutex_unlock(&spi_add_lock);
440 return status;
Grant Likelydc87c982008-05-15 16:50:22 -0600441}
442EXPORT_SYMBOL_GPL(spi_add_device);
David Brownell8ae12a02006-01-08 13:34:19 -0800443
David Brownell33e34dc2007-05-08 00:32:21 -0700444/**
445 * spi_new_device - instantiate one new SPI device
446 * @master: Controller to which device is connected
447 * @chip: Describes the SPI device
448 * Context: can sleep
449 *
450 * On typical mainboards, this is purely internal; and it's not needed
David Brownell8ae12a02006-01-08 13:34:19 -0800451 * after board init creates the hard-wired devices. Some development
452 * platforms may not be able to use spi_register_board_info though, and
453 * this is exported so that for example a USB or parport based adapter
454 * driver could add devices (which it would learn about out-of-band).
David Brownell082c8cb2007-07-31 00:39:45 -0700455 *
456 * Returns the new device, or NULL.
David Brownell8ae12a02006-01-08 13:34:19 -0800457 */
Adrian Bunke9d5a462007-03-26 21:32:23 -0800458struct spi_device *spi_new_device(struct spi_master *master,
459 struct spi_board_info *chip)
David Brownell8ae12a02006-01-08 13:34:19 -0800460{
461 struct spi_device *proxy;
David Brownell8ae12a02006-01-08 13:34:19 -0800462 int status;
463
David Brownell082c8cb2007-07-31 00:39:45 -0700464 /* NOTE: caller did any chip->bus_num checks necessary.
465 *
466 * Also, unless we change the return value convention to use
467 * error-or-pointer (not NULL-or-pointer), troubleshootability
468 * suggests syslogged diagnostics are best here (ugh).
469 */
470
Grant Likelydc87c982008-05-15 16:50:22 -0600471 proxy = spi_alloc_device(master);
472 if (!proxy)
David Brownell8ae12a02006-01-08 13:34:19 -0800473 return NULL;
474
Grant Likely102eb972008-07-23 21:29:55 -0700475 WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
476
David Brownell8ae12a02006-01-08 13:34:19 -0800477 proxy->chip_select = chip->chip_select;
478 proxy->max_speed_hz = chip->max_speed_hz;
David Brownell980a01c2006-06-28 07:47:15 -0700479 proxy->mode = chip->mode;
David Brownell8ae12a02006-01-08 13:34:19 -0800480 proxy->irq = chip->irq;
Grant Likely102eb972008-07-23 21:29:55 -0700481 strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
David Brownell8ae12a02006-01-08 13:34:19 -0800482 proxy->dev.platform_data = (void *) chip->platform_data;
483 proxy->controller_data = chip->controller_data;
484 proxy->controller_state = NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800485
Grant Likelydc87c982008-05-15 16:50:22 -0600486 status = spi_add_device(proxy);
David Brownell8ae12a02006-01-08 13:34:19 -0800487 if (status < 0) {
Grant Likelydc87c982008-05-15 16:50:22 -0600488 spi_dev_put(proxy);
489 return NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800490 }
491
David Brownell8ae12a02006-01-08 13:34:19 -0800492 return proxy;
493}
494EXPORT_SYMBOL_GPL(spi_new_device);
495
Feng Tang2b9603a2010-08-02 15:52:15 +0800496static void spi_match_master_to_boardinfo(struct spi_master *master,
497 struct spi_board_info *bi)
498{
499 struct spi_device *dev;
500
501 if (master->bus_num != bi->bus_num)
502 return;
503
504 dev = spi_new_device(master, bi);
505 if (!dev)
506 dev_err(master->dev.parent, "can't create new device for %s\n",
507 bi->modalias);
508}
509
David Brownell33e34dc2007-05-08 00:32:21 -0700510/**
511 * spi_register_board_info - register SPI devices for a given board
512 * @info: array of chip descriptors
513 * @n: how many descriptors are provided
514 * Context: can sleep
515 *
David Brownell8ae12a02006-01-08 13:34:19 -0800516 * Board-specific early init code calls this (probably during arch_initcall)
517 * with segments of the SPI device table. Any device nodes are created later,
518 * after the relevant parent SPI controller (bus_num) is defined. We keep
519 * this table of devices forever, so that reloading a controller driver will
520 * not make Linux forget about these hard-wired devices.
521 *
522 * Other code can also call this, e.g. a particular add-on board might provide
523 * SPI devices through its expansion connector, so code initializing that board
524 * would naturally declare its SPI devices.
525 *
526 * The board info passed can safely be __initdata ... but be careful of
527 * any embedded pointers (platform_data, etc), they're copied as-is.
528 */
Grant Likelyfd4a3192012-12-07 16:57:14 +0000529int spi_register_board_info(struct spi_board_info const *info, unsigned n)
David Brownell8ae12a02006-01-08 13:34:19 -0800530{
Feng Tang2b9603a2010-08-02 15:52:15 +0800531 struct boardinfo *bi;
532 int i;
David Brownell8ae12a02006-01-08 13:34:19 -0800533
Feng Tang2b9603a2010-08-02 15:52:15 +0800534 bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
David Brownell8ae12a02006-01-08 13:34:19 -0800535 if (!bi)
536 return -ENOMEM;
David Brownell8ae12a02006-01-08 13:34:19 -0800537
Feng Tang2b9603a2010-08-02 15:52:15 +0800538 for (i = 0; i < n; i++, bi++, info++) {
539 struct spi_master *master;
David Brownell8ae12a02006-01-08 13:34:19 -0800540
Feng Tang2b9603a2010-08-02 15:52:15 +0800541 memcpy(&bi->board_info, info, sizeof(*info));
542 mutex_lock(&board_lock);
543 list_add_tail(&bi->list, &board_list);
544 list_for_each_entry(master, &spi_master_list, list)
545 spi_match_master_to_boardinfo(master, &bi->board_info);
546 mutex_unlock(&board_lock);
David Brownell8ae12a02006-01-08 13:34:19 -0800547 }
Feng Tang2b9603a2010-08-02 15:52:15 +0800548
549 return 0;
David Brownell8ae12a02006-01-08 13:34:19 -0800550}
551
552/*-------------------------------------------------------------------------*/
553
Mark Brownb1589352013-10-05 11:50:40 +0100554static void spi_set_cs(struct spi_device *spi, bool enable)
555{
556 if (spi->mode & SPI_CS_HIGH)
557 enable = !enable;
558
559 if (spi->cs_gpio >= 0)
560 gpio_set_value(spi->cs_gpio, !enable);
561 else if (spi->master->set_cs)
562 spi->master->set_cs(spi, !enable);
563}
564
565/*
566 * spi_transfer_one_message - Default implementation of transfer_one_message()
567 *
568 * This is a standard implementation of transfer_one_message() for
569 * drivers which impelment a transfer_one() operation. It provides
570 * standard handling of delays and chip select management.
571 */
572static int spi_transfer_one_message(struct spi_master *master,
573 struct spi_message *msg)
574{
575 struct spi_transfer *xfer;
576 bool cur_cs = true;
577 bool keep_cs = false;
578 int ret = 0;
579
580 spi_set_cs(msg->spi, true);
581
582 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
583 trace_spi_transfer_start(msg, xfer);
584
Wolfram Sang16735d02013-11-14 14:32:02 -0800585 reinit_completion(&master->xfer_completion);
Mark Brownb1589352013-10-05 11:50:40 +0100586
587 ret = master->transfer_one(master, msg->spi, xfer);
588 if (ret < 0) {
589 dev_err(&msg->spi->dev,
590 "SPI transfer failed: %d\n", ret);
591 goto out;
592 }
593
594 if (ret > 0)
595 wait_for_completion(&master->xfer_completion);
596
597 trace_spi_transfer_stop(msg, xfer);
598
599 if (msg->status != -EINPROGRESS)
600 goto out;
601
602 if (xfer->delay_usecs)
603 udelay(xfer->delay_usecs);
604
605 if (xfer->cs_change) {
606 if (list_is_last(&xfer->transfer_list,
607 &msg->transfers)) {
608 keep_cs = true;
609 } else {
610 cur_cs = !cur_cs;
611 spi_set_cs(msg->spi, cur_cs);
612 }
613 }
614
615 msg->actual_length += xfer->len;
616 }
617
618out:
619 if (ret != 0 || !keep_cs)
620 spi_set_cs(msg->spi, false);
621
622 if (msg->status == -EINPROGRESS)
623 msg->status = ret;
624
625 spi_finalize_current_message(master);
626
627 return ret;
628}
629
630/**
631 * spi_finalize_current_transfer - report completion of a transfer
632 *
633 * Called by SPI drivers using the core transfer_one_message()
634 * implementation to notify it that the current interrupt driven
635 * transfer has finised and the next one may be scheduled.
636 */
637void spi_finalize_current_transfer(struct spi_master *master)
638{
639 complete(&master->xfer_completion);
640}
641EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
642
Linus Walleijffbbdd212012-02-22 10:05:38 +0100643/**
644 * spi_pump_messages - kthread work function which processes spi message queue
645 * @work: pointer to kthread work struct contained in the master struct
646 *
647 * This function checks if there is any spi message in the queue that
648 * needs processing and if so call out to the driver to initialize hardware
649 * and transfer each message.
650 *
651 */
652static void spi_pump_messages(struct kthread_work *work)
653{
654 struct spi_master *master =
655 container_of(work, struct spi_master, pump_messages);
656 unsigned long flags;
657 bool was_busy = false;
658 int ret;
659
660 /* Lock queue and check for queue work */
661 spin_lock_irqsave(&master->queue_lock, flags);
662 if (list_empty(&master->queue) || !master->running) {
Bryan Freedb0b36b82013-03-13 11:17:40 -0700663 if (!master->busy) {
664 spin_unlock_irqrestore(&master->queue_lock, flags);
665 return;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100666 }
667 master->busy = false;
668 spin_unlock_irqrestore(&master->queue_lock, flags);
Bryan Freedb0b36b82013-03-13 11:17:40 -0700669 if (master->unprepare_transfer_hardware &&
670 master->unprepare_transfer_hardware(master))
671 dev_err(&master->dev,
672 "failed to unprepare transfer hardware\n");
Mark Brown49834de2013-07-28 14:47:02 +0100673 if (master->auto_runtime_pm) {
674 pm_runtime_mark_last_busy(master->dev.parent);
675 pm_runtime_put_autosuspend(master->dev.parent);
676 }
Mark Brown56ec1972013-10-07 19:33:53 +0100677 trace_spi_master_idle(master);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100678 return;
679 }
680
681 /* Make sure we are not already running a message */
682 if (master->cur_msg) {
683 spin_unlock_irqrestore(&master->queue_lock, flags);
684 return;
685 }
686 /* Extract head of queue */
687 master->cur_msg =
688 list_entry(master->queue.next, struct spi_message, queue);
689
690 list_del_init(&master->cur_msg->queue);
691 if (master->busy)
692 was_busy = true;
693 else
694 master->busy = true;
695 spin_unlock_irqrestore(&master->queue_lock, flags);
696
Mark Brown49834de2013-07-28 14:47:02 +0100697 if (!was_busy && master->auto_runtime_pm) {
698 ret = pm_runtime_get_sync(master->dev.parent);
699 if (ret < 0) {
700 dev_err(&master->dev, "Failed to power device: %d\n",
701 ret);
702 return;
703 }
704 }
705
Mark Brown56ec1972013-10-07 19:33:53 +0100706 if (!was_busy)
707 trace_spi_master_busy(master);
708
Shubhrajyoti D7dfd2bd2012-05-10 19:20:41 +0530709 if (!was_busy && master->prepare_transfer_hardware) {
Linus Walleijffbbdd212012-02-22 10:05:38 +0100710 ret = master->prepare_transfer_hardware(master);
711 if (ret) {
712 dev_err(&master->dev,
713 "failed to prepare transfer hardware\n");
Mark Brown49834de2013-07-28 14:47:02 +0100714
715 if (master->auto_runtime_pm)
716 pm_runtime_put(master->dev.parent);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100717 return;
718 }
719 }
720
Mark Brown56ec1972013-10-07 19:33:53 +0100721 trace_spi_message_start(master->cur_msg);
722
Mark Brown2841a5f2013-10-05 00:23:12 +0100723 if (master->prepare_message) {
724 ret = master->prepare_message(master, master->cur_msg);
725 if (ret) {
726 dev_err(&master->dev,
727 "failed to prepare message: %d\n", ret);
728 master->cur_msg->status = ret;
729 spi_finalize_current_message(master);
730 return;
731 }
732 master->cur_msg_prepared = true;
733 }
734
Linus Walleijffbbdd212012-02-22 10:05:38 +0100735 ret = master->transfer_one_message(master, master->cur_msg);
736 if (ret) {
737 dev_err(&master->dev,
738 "failed to transfer one message from queue\n");
739 return;
740 }
741}
742
743static int spi_init_queue(struct spi_master *master)
744{
745 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
746
747 INIT_LIST_HEAD(&master->queue);
748 spin_lock_init(&master->queue_lock);
749
750 master->running = false;
751 master->busy = false;
752
753 init_kthread_worker(&master->kworker);
754 master->kworker_task = kthread_run(kthread_worker_fn,
Kees Cookf1701682013-07-03 15:04:58 -0700755 &master->kworker, "%s",
Linus Walleijffbbdd212012-02-22 10:05:38 +0100756 dev_name(&master->dev));
757 if (IS_ERR(master->kworker_task)) {
758 dev_err(&master->dev, "failed to create message pump task\n");
759 return -ENOMEM;
760 }
761 init_kthread_work(&master->pump_messages, spi_pump_messages);
762
763 /*
764 * Master config will indicate if this controller should run the
765 * message pump with high (realtime) priority to reduce the transfer
766 * latency on the bus by minimising the delay between a transfer
767 * request and the scheduling of the message pump thread. Without this
768 * setting the message pump thread will remain at default priority.
769 */
770 if (master->rt) {
771 dev_info(&master->dev,
772 "will run message pump with realtime priority\n");
773 sched_setscheduler(master->kworker_task, SCHED_FIFO, &param);
774 }
775
776 return 0;
777}
778
779/**
780 * spi_get_next_queued_message() - called by driver to check for queued
781 * messages
782 * @master: the master to check for queued messages
783 *
784 * If there are more messages in the queue, the next message is returned from
785 * this call.
786 */
787struct spi_message *spi_get_next_queued_message(struct spi_master *master)
788{
789 struct spi_message *next;
790 unsigned long flags;
791
792 /* get a pointer to the next message, if any */
793 spin_lock_irqsave(&master->queue_lock, flags);
794 if (list_empty(&master->queue))
795 next = NULL;
796 else
797 next = list_entry(master->queue.next,
798 struct spi_message, queue);
799 spin_unlock_irqrestore(&master->queue_lock, flags);
800
801 return next;
802}
803EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
804
805/**
806 * spi_finalize_current_message() - the current message is complete
807 * @master: the master to return the message to
808 *
809 * Called by the driver to notify the core that the message in the front of the
810 * queue is complete and can be removed from the queue.
811 */
812void spi_finalize_current_message(struct spi_master *master)
813{
814 struct spi_message *mesg;
815 unsigned long flags;
Mark Brown2841a5f2013-10-05 00:23:12 +0100816 int ret;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100817
818 spin_lock_irqsave(&master->queue_lock, flags);
819 mesg = master->cur_msg;
820 master->cur_msg = NULL;
821
822 queue_kthread_work(&master->kworker, &master->pump_messages);
823 spin_unlock_irqrestore(&master->queue_lock, flags);
824
Mark Brown2841a5f2013-10-05 00:23:12 +0100825 if (master->cur_msg_prepared && master->unprepare_message) {
826 ret = master->unprepare_message(master, mesg);
827 if (ret) {
828 dev_err(&master->dev,
829 "failed to unprepare message: %d\n", ret);
830 }
831 }
832 master->cur_msg_prepared = false;
833
Linus Walleijffbbdd212012-02-22 10:05:38 +0100834 mesg->state = NULL;
835 if (mesg->complete)
836 mesg->complete(mesg->context);
Mark Brown56ec1972013-10-07 19:33:53 +0100837
838 trace_spi_message_done(mesg);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100839}
840EXPORT_SYMBOL_GPL(spi_finalize_current_message);
841
842static int spi_start_queue(struct spi_master *master)
843{
844 unsigned long flags;
845
846 spin_lock_irqsave(&master->queue_lock, flags);
847
848 if (master->running || master->busy) {
849 spin_unlock_irqrestore(&master->queue_lock, flags);
850 return -EBUSY;
851 }
852
853 master->running = true;
854 master->cur_msg = NULL;
855 spin_unlock_irqrestore(&master->queue_lock, flags);
856
857 queue_kthread_work(&master->kworker, &master->pump_messages);
858
859 return 0;
860}
861
862static int spi_stop_queue(struct spi_master *master)
863{
864 unsigned long flags;
865 unsigned limit = 500;
866 int ret = 0;
867
868 spin_lock_irqsave(&master->queue_lock, flags);
869
870 /*
871 * This is a bit lame, but is optimized for the common execution path.
872 * A wait_queue on the master->busy could be used, but then the common
873 * execution path (pump_messages) would be required to call wake_up or
874 * friends on every SPI message. Do this instead.
875 */
876 while ((!list_empty(&master->queue) || master->busy) && limit--) {
877 spin_unlock_irqrestore(&master->queue_lock, flags);
878 msleep(10);
879 spin_lock_irqsave(&master->queue_lock, flags);
880 }
881
882 if (!list_empty(&master->queue) || master->busy)
883 ret = -EBUSY;
884 else
885 master->running = false;
886
887 spin_unlock_irqrestore(&master->queue_lock, flags);
888
889 if (ret) {
890 dev_warn(&master->dev,
891 "could not stop message queue\n");
892 return ret;
893 }
894 return ret;
895}
896
897static int spi_destroy_queue(struct spi_master *master)
898{
899 int ret;
900
901 ret = spi_stop_queue(master);
902
903 /*
904 * flush_kthread_worker will block until all work is done.
905 * If the reason that stop_queue timed out is that the work will never
906 * finish, then it does no good to call flush/stop thread, so
907 * return anyway.
908 */
909 if (ret) {
910 dev_err(&master->dev, "problem destroying queue\n");
911 return ret;
912 }
913
914 flush_kthread_worker(&master->kworker);
915 kthread_stop(master->kworker_task);
916
917 return 0;
918}
919
920/**
921 * spi_queued_transfer - transfer function for queued transfers
922 * @spi: spi device which is requesting transfer
923 * @msg: spi message which is to handled is queued to driver queue
924 */
925static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
926{
927 struct spi_master *master = spi->master;
928 unsigned long flags;
929
930 spin_lock_irqsave(&master->queue_lock, flags);
931
932 if (!master->running) {
933 spin_unlock_irqrestore(&master->queue_lock, flags);
934 return -ESHUTDOWN;
935 }
936 msg->actual_length = 0;
937 msg->status = -EINPROGRESS;
938
939 list_add_tail(&msg->queue, &master->queue);
Axel Lin96b3eac2013-08-22 23:41:34 +0800940 if (!master->busy)
Linus Walleijffbbdd212012-02-22 10:05:38 +0100941 queue_kthread_work(&master->kworker, &master->pump_messages);
942
943 spin_unlock_irqrestore(&master->queue_lock, flags);
944 return 0;
945}
946
947static int spi_master_initialize_queue(struct spi_master *master)
948{
949 int ret;
950
951 master->queued = true;
952 master->transfer = spi_queued_transfer;
Mark Brownb1589352013-10-05 11:50:40 +0100953 if (!master->transfer_one_message)
954 master->transfer_one_message = spi_transfer_one_message;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100955
956 /* Initialize and start queue */
957 ret = spi_init_queue(master);
958 if (ret) {
959 dev_err(&master->dev, "problem initializing queue\n");
960 goto err_init_queue;
961 }
962 ret = spi_start_queue(master);
963 if (ret) {
964 dev_err(&master->dev, "problem starting queue\n");
965 goto err_start_queue;
966 }
967
968 return 0;
969
970err_start_queue:
971err_init_queue:
972 spi_destroy_queue(master);
973 return ret;
974}
975
976/*-------------------------------------------------------------------------*/
977
Andreas Larsson7cb94362012-12-04 15:09:38 +0100978#if defined(CONFIG_OF)
Grant Likelyd57a4282012-04-07 14:16:53 -0600979/**
980 * of_register_spi_devices() - Register child devices onto the SPI bus
981 * @master: Pointer to spi_master device
982 *
983 * Registers an spi_device for each child node of master node which has a 'reg'
984 * property.
985 */
986static void of_register_spi_devices(struct spi_master *master)
987{
988 struct spi_device *spi;
989 struct device_node *nc;
Grant Likelyd57a4282012-04-07 14:16:53 -0600990 int rc;
Trent Piepho89da4292013-09-27 05:37:25 -0700991 u32 value;
Grant Likelyd57a4282012-04-07 14:16:53 -0600992
993 if (!master->dev.of_node)
994 return;
995
Alexander Sverdlinf3b61592012-11-29 08:59:29 +0100996 for_each_available_child_of_node(master->dev.of_node, nc) {
Grant Likelyd57a4282012-04-07 14:16:53 -0600997 /* Alloc an spi_device */
998 spi = spi_alloc_device(master);
999 if (!spi) {
1000 dev_err(&master->dev, "spi_device alloc error for %s\n",
1001 nc->full_name);
1002 spi_dev_put(spi);
1003 continue;
1004 }
1005
1006 /* Select device driver */
1007 if (of_modalias_node(nc, spi->modalias,
1008 sizeof(spi->modalias)) < 0) {
1009 dev_err(&master->dev, "cannot find modalias for %s\n",
1010 nc->full_name);
1011 spi_dev_put(spi);
1012 continue;
1013 }
1014
1015 /* Device address */
Trent Piepho89da4292013-09-27 05:37:25 -07001016 rc = of_property_read_u32(nc, "reg", &value);
1017 if (rc) {
1018 dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
1019 nc->full_name, rc);
Grant Likelyd57a4282012-04-07 14:16:53 -06001020 spi_dev_put(spi);
1021 continue;
1022 }
Trent Piepho89da4292013-09-27 05:37:25 -07001023 spi->chip_select = value;
Grant Likelyd57a4282012-04-07 14:16:53 -06001024
1025 /* Mode (clock phase/polarity/etc.) */
1026 if (of_find_property(nc, "spi-cpha", NULL))
1027 spi->mode |= SPI_CPHA;
1028 if (of_find_property(nc, "spi-cpol", NULL))
1029 spi->mode |= SPI_CPOL;
1030 if (of_find_property(nc, "spi-cs-high", NULL))
1031 spi->mode |= SPI_CS_HIGH;
Lars-Peter Clausenc20151d2012-12-06 16:55:33 +01001032 if (of_find_property(nc, "spi-3wire", NULL))
1033 spi->mode |= SPI_3WIRE;
Grant Likelyd57a4282012-04-07 14:16:53 -06001034
wangyuhangf477b7f2013-08-11 18:15:17 +08001035 /* Device DUAL/QUAD mode */
Trent Piepho89da4292013-09-27 05:37:25 -07001036 if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
1037 switch (value) {
1038 case 1:
Mark Browna822e992013-08-30 23:19:40 +01001039 break;
Trent Piepho89da4292013-09-27 05:37:25 -07001040 case 2:
Mark Browna822e992013-08-30 23:19:40 +01001041 spi->mode |= SPI_TX_DUAL;
1042 break;
Trent Piepho89da4292013-09-27 05:37:25 -07001043 case 4:
Mark Browna822e992013-08-30 23:19:40 +01001044 spi->mode |= SPI_TX_QUAD;
1045 break;
1046 default:
1047 dev_err(&master->dev,
wangyuhanga110f932013-09-01 17:36:21 +08001048 "spi-tx-bus-width %d not supported\n",
Trent Piepho89da4292013-09-27 05:37:25 -07001049 value);
Mark Browna822e992013-08-30 23:19:40 +01001050 spi_dev_put(spi);
1051 continue;
1052 }
wangyuhangf477b7f2013-08-11 18:15:17 +08001053 }
1054
Trent Piepho89da4292013-09-27 05:37:25 -07001055 if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
1056 switch (value) {
1057 case 1:
Mark Browna822e992013-08-30 23:19:40 +01001058 break;
Trent Piepho89da4292013-09-27 05:37:25 -07001059 case 2:
Mark Browna822e992013-08-30 23:19:40 +01001060 spi->mode |= SPI_RX_DUAL;
1061 break;
Trent Piepho89da4292013-09-27 05:37:25 -07001062 case 4:
Mark Browna822e992013-08-30 23:19:40 +01001063 spi->mode |= SPI_RX_QUAD;
1064 break;
1065 default:
1066 dev_err(&master->dev,
wangyuhanga110f932013-09-01 17:36:21 +08001067 "spi-rx-bus-width %d not supported\n",
Trent Piepho89da4292013-09-27 05:37:25 -07001068 value);
Mark Browna822e992013-08-30 23:19:40 +01001069 spi_dev_put(spi);
1070 continue;
1071 }
wangyuhangf477b7f2013-08-11 18:15:17 +08001072 }
1073
Grant Likelyd57a4282012-04-07 14:16:53 -06001074 /* Device speed */
Trent Piepho89da4292013-09-27 05:37:25 -07001075 rc = of_property_read_u32(nc, "spi-max-frequency", &value);
1076 if (rc) {
1077 dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
1078 nc->full_name, rc);
Grant Likelyd57a4282012-04-07 14:16:53 -06001079 spi_dev_put(spi);
1080 continue;
1081 }
Trent Piepho89da4292013-09-27 05:37:25 -07001082 spi->max_speed_hz = value;
Grant Likelyd57a4282012-04-07 14:16:53 -06001083
1084 /* IRQ */
1085 spi->irq = irq_of_parse_and_map(nc, 0);
1086
1087 /* Store a pointer to the node in the device structure */
1088 of_node_get(nc);
1089 spi->dev.of_node = nc;
1090
1091 /* Register the new device */
Mathias Krause70fac172013-08-31 20:24:14 +02001092 request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
Grant Likelyd57a4282012-04-07 14:16:53 -06001093 rc = spi_add_device(spi);
1094 if (rc) {
1095 dev_err(&master->dev, "spi_device register error %s\n",
1096 nc->full_name);
1097 spi_dev_put(spi);
1098 }
1099
1100 }
1101}
1102#else
1103static void of_register_spi_devices(struct spi_master *master) { }
1104#endif
1105
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001106#ifdef CONFIG_ACPI
1107static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
1108{
1109 struct spi_device *spi = data;
1110
1111 if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
1112 struct acpi_resource_spi_serialbus *sb;
1113
1114 sb = &ares->data.spi_serial_bus;
1115 if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
1116 spi->chip_select = sb->device_selection;
1117 spi->max_speed_hz = sb->connection_speed;
1118
1119 if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
1120 spi->mode |= SPI_CPHA;
1121 if (sb->clock_polarity == ACPI_SPI_START_HIGH)
1122 spi->mode |= SPI_CPOL;
1123 if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
1124 spi->mode |= SPI_CS_HIGH;
1125 }
1126 } else if (spi->irq < 0) {
1127 struct resource r;
1128
1129 if (acpi_dev_resource_interrupt(ares, 0, &r))
1130 spi->irq = r.start;
1131 }
1132
1133 /* Always tell the ACPI core to skip this resource */
1134 return 1;
1135}
1136
1137static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
1138 void *data, void **return_value)
1139{
1140 struct spi_master *master = data;
1141 struct list_head resource_list;
1142 struct acpi_device *adev;
1143 struct spi_device *spi;
1144 int ret;
1145
1146 if (acpi_bus_get_device(handle, &adev))
1147 return AE_OK;
1148 if (acpi_bus_get_status(adev) || !adev->status.present)
1149 return AE_OK;
1150
1151 spi = spi_alloc_device(master);
1152 if (!spi) {
1153 dev_err(&master->dev, "failed to allocate SPI device for %s\n",
1154 dev_name(&adev->dev));
1155 return AE_NO_MEMORY;
1156 }
1157
Rafael J. Wysocki7b199812013-11-11 22:41:56 +01001158 ACPI_COMPANION_SET(&spi->dev, adev);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001159 spi->irq = -1;
1160
1161 INIT_LIST_HEAD(&resource_list);
1162 ret = acpi_dev_get_resources(adev, &resource_list,
1163 acpi_spi_add_resource, spi);
1164 acpi_dev_free_resource_list(&resource_list);
1165
1166 if (ret < 0 || !spi->max_speed_hz) {
1167 spi_dev_put(spi);
1168 return AE_OK;
1169 }
1170
Mika Westerberg33cf00e2013-10-10 13:28:48 +03001171 adev->power.flags.ignore_parent = true;
Jarkko Nikulacf9eb392013-10-10 17:19:17 +03001172 strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001173 if (spi_add_device(spi)) {
Mika Westerberg33cf00e2013-10-10 13:28:48 +03001174 adev->power.flags.ignore_parent = false;
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001175 dev_err(&master->dev, "failed to add SPI device %s from ACPI\n",
1176 dev_name(&adev->dev));
1177 spi_dev_put(spi);
1178 }
1179
1180 return AE_OK;
1181}
1182
1183static void acpi_register_spi_devices(struct spi_master *master)
1184{
1185 acpi_status status;
1186 acpi_handle handle;
1187
Rafael J. Wysocki29896172013-04-01 00:21:08 +00001188 handle = ACPI_HANDLE(master->dev.parent);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001189 if (!handle)
1190 return;
1191
1192 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1193 acpi_spi_add_device, NULL,
1194 master, NULL);
1195 if (ACPI_FAILURE(status))
1196 dev_warn(&master->dev, "failed to enumerate SPI slaves\n");
1197}
1198#else
1199static inline void acpi_register_spi_devices(struct spi_master *master) {}
1200#endif /* CONFIG_ACPI */
1201
Tony Jones49dce682007-10-16 01:27:48 -07001202static void spi_master_release(struct device *dev)
David Brownell8ae12a02006-01-08 13:34:19 -08001203{
1204 struct spi_master *master;
1205
Tony Jones49dce682007-10-16 01:27:48 -07001206 master = container_of(dev, struct spi_master, dev);
David Brownell8ae12a02006-01-08 13:34:19 -08001207 kfree(master);
1208}
1209
1210static struct class spi_master_class = {
1211 .name = "spi_master",
1212 .owner = THIS_MODULE,
Tony Jones49dce682007-10-16 01:27:48 -07001213 .dev_release = spi_master_release,
David Brownell8ae12a02006-01-08 13:34:19 -08001214};
1215
1216
Linus Walleijffbbdd212012-02-22 10:05:38 +01001217
David Brownell8ae12a02006-01-08 13:34:19 -08001218/**
1219 * spi_alloc_master - allocate SPI master controller
1220 * @dev: the controller, possibly using the platform_bus
David Brownell33e34dc2007-05-08 00:32:21 -07001221 * @size: how much zeroed driver-private data to allocate; the pointer to this
Tony Jones49dce682007-10-16 01:27:48 -07001222 * memory is in the driver_data field of the returned device,
David Brownell0c868462006-01-08 13:34:25 -08001223 * accessible with spi_master_get_devdata().
David Brownell33e34dc2007-05-08 00:32:21 -07001224 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001225 *
1226 * This call is used only by SPI master controller drivers, which are the
1227 * only ones directly touching chip registers. It's how they allocate
dmitry pervushinba1a0512006-05-20 15:00:14 -07001228 * an spi_master structure, prior to calling spi_register_master().
David Brownell8ae12a02006-01-08 13:34:19 -08001229 *
1230 * This must be called from context that can sleep. It returns the SPI
1231 * master structure on success, else NULL.
1232 *
1233 * The caller is responsible for assigning the bus number and initializing
dmitry pervushinba1a0512006-05-20 15:00:14 -07001234 * the master's methods before calling spi_register_master(); and (after errors
Uwe Kleine-Königeb4af0f2012-02-23 10:40:14 +01001235 * adding the device) calling spi_master_put() and kfree() to prevent a memory
1236 * leak.
David Brownell8ae12a02006-01-08 13:34:19 -08001237 */
Adrian Bunke9d5a462007-03-26 21:32:23 -08001238struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
David Brownell8ae12a02006-01-08 13:34:19 -08001239{
1240 struct spi_master *master;
1241
David Brownell0c868462006-01-08 13:34:25 -08001242 if (!dev)
1243 return NULL;
1244
Jingoo Han5fe5f052013-10-14 10:31:51 +09001245 master = kzalloc(size + sizeof(*master), GFP_KERNEL);
David Brownell8ae12a02006-01-08 13:34:19 -08001246 if (!master)
1247 return NULL;
1248
Tony Jones49dce682007-10-16 01:27:48 -07001249 device_initialize(&master->dev);
Grant Likely1e8a52e2012-05-19 23:42:08 -06001250 master->bus_num = -1;
1251 master->num_chipselect = 1;
Tony Jones49dce682007-10-16 01:27:48 -07001252 master->dev.class = &spi_master_class;
1253 master->dev.parent = get_device(dev);
David Brownell0c868462006-01-08 13:34:25 -08001254 spi_master_set_devdata(master, &master[1]);
David Brownell8ae12a02006-01-08 13:34:19 -08001255
1256 return master;
1257}
1258EXPORT_SYMBOL_GPL(spi_alloc_master);
1259
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001260#ifdef CONFIG_OF
1261static int of_spi_register_master(struct spi_master *master)
1262{
Grant Likelye80beb22013-02-12 17:48:37 +00001263 int nb, i, *cs;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001264 struct device_node *np = master->dev.of_node;
1265
1266 if (!np)
1267 return 0;
1268
1269 nb = of_gpio_named_count(np, "cs-gpios");
Jingoo Han5fe5f052013-10-14 10:31:51 +09001270 master->num_chipselect = max_t(int, nb, master->num_chipselect);
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001271
Andreas Larsson8ec5d842013-02-13 14:23:24 +01001272 /* Return error only for an incorrectly formed cs-gpios property */
1273 if (nb == 0 || nb == -ENOENT)
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001274 return 0;
Andreas Larsson8ec5d842013-02-13 14:23:24 +01001275 else if (nb < 0)
1276 return nb;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001277
1278 cs = devm_kzalloc(&master->dev,
1279 sizeof(int) * master->num_chipselect,
1280 GFP_KERNEL);
1281 master->cs_gpios = cs;
1282
1283 if (!master->cs_gpios)
1284 return -ENOMEM;
1285
Andreas Larsson0da83bb2013-01-29 15:53:40 +01001286 for (i = 0; i < master->num_chipselect; i++)
Andreas Larsson446411e2013-02-13 14:20:25 +01001287 cs[i] = -ENOENT;
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001288
1289 for (i = 0; i < nb; i++)
1290 cs[i] = of_get_named_gpio(np, "cs-gpios", i);
1291
1292 return 0;
1293}
1294#else
1295static int of_spi_register_master(struct spi_master *master)
1296{
1297 return 0;
1298}
1299#endif
1300
David Brownell8ae12a02006-01-08 13:34:19 -08001301/**
1302 * spi_register_master - register SPI master controller
1303 * @master: initialized master, originally from spi_alloc_master()
David Brownell33e34dc2007-05-08 00:32:21 -07001304 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001305 *
1306 * SPI master controllers connect to their drivers using some non-SPI bus,
1307 * such as the platform bus. The final stage of probe() in that code
1308 * includes calling spi_register_master() to hook up to this SPI bus glue.
1309 *
1310 * SPI controllers use board specific (often SOC specific) bus numbers,
1311 * and board-specific addressing for SPI devices combines those numbers
1312 * with chip select numbers. Since SPI does not directly support dynamic
1313 * device identification, boards need configuration tables telling which
1314 * chip is at which address.
1315 *
1316 * This must be called from context that can sleep. It returns zero on
1317 * success, else a negative error code (dropping the master's refcount).
David Brownell0c868462006-01-08 13:34:25 -08001318 * After a successful return, the caller is responsible for calling
1319 * spi_unregister_master().
David Brownell8ae12a02006-01-08 13:34:19 -08001320 */
Adrian Bunke9d5a462007-03-26 21:32:23 -08001321int spi_register_master(struct spi_master *master)
David Brownell8ae12a02006-01-08 13:34:19 -08001322{
David Brownelle44a45a2007-06-03 13:50:40 -07001323 static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1);
Tony Jones49dce682007-10-16 01:27:48 -07001324 struct device *dev = master->dev.parent;
Feng Tang2b9603a2010-08-02 15:52:15 +08001325 struct boardinfo *bi;
David Brownell8ae12a02006-01-08 13:34:19 -08001326 int status = -ENODEV;
1327 int dynamic = 0;
1328
David Brownell0c868462006-01-08 13:34:25 -08001329 if (!dev)
1330 return -ENODEV;
1331
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +01001332 status = of_spi_register_master(master);
1333 if (status)
1334 return status;
1335
David Brownell082c8cb2007-07-31 00:39:45 -07001336 /* even if it's just one always-selected device, there must
1337 * be at least one chipselect
1338 */
1339 if (master->num_chipselect == 0)
1340 return -EINVAL;
1341
Grant Likelybb297852012-12-21 19:32:09 +00001342 if ((master->bus_num < 0) && master->dev.of_node)
1343 master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
1344
David Brownell8ae12a02006-01-08 13:34:19 -08001345 /* convention: dynamically assigned bus IDs count down from the max */
David Brownella020ed72006-04-03 15:49:04 -07001346 if (master->bus_num < 0) {
David Brownell082c8cb2007-07-31 00:39:45 -07001347 /* FIXME switch to an IDR based scheme, something like
1348 * I2C now uses, so we can't run out of "dynamic" IDs
1349 */
David Brownell8ae12a02006-01-08 13:34:19 -08001350 master->bus_num = atomic_dec_return(&dyn_bus_id);
David Brownellb8852442006-01-08 13:34:23 -08001351 dynamic = 1;
David Brownell8ae12a02006-01-08 13:34:19 -08001352 }
1353
Ernst Schwabcf32b712010-06-28 17:49:29 -07001354 spin_lock_init(&master->bus_lock_spinlock);
1355 mutex_init(&master->bus_lock_mutex);
1356 master->bus_lock_flag = 0;
Mark Brownb1589352013-10-05 11:50:40 +01001357 init_completion(&master->xfer_completion);
Ernst Schwabcf32b712010-06-28 17:49:29 -07001358
David Brownell8ae12a02006-01-08 13:34:19 -08001359 /* register the device, then userspace will see it.
1360 * registration fails if the bus ID is in use.
1361 */
Kay Sievers35f74fc2009-01-06 10:44:37 -08001362 dev_set_name(&master->dev, "spi%u", master->bus_num);
Tony Jones49dce682007-10-16 01:27:48 -07001363 status = device_add(&master->dev);
David Brownellb8852442006-01-08 13:34:23 -08001364 if (status < 0)
David Brownell8ae12a02006-01-08 13:34:19 -08001365 goto done;
Kay Sievers35f74fc2009-01-06 10:44:37 -08001366 dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
David Brownell8ae12a02006-01-08 13:34:19 -08001367 dynamic ? " (dynamic)" : "");
1368
Linus Walleijffbbdd212012-02-22 10:05:38 +01001369 /* If we're using a queued driver, start the queue */
1370 if (master->transfer)
1371 dev_info(dev, "master is unqueued, this is deprecated\n");
1372 else {
1373 status = spi_master_initialize_queue(master);
1374 if (status) {
Axel Line93b0722013-08-31 20:25:52 +08001375 device_del(&master->dev);
Linus Walleijffbbdd212012-02-22 10:05:38 +01001376 goto done;
1377 }
1378 }
1379
Feng Tang2b9603a2010-08-02 15:52:15 +08001380 mutex_lock(&board_lock);
1381 list_add_tail(&master->list, &spi_master_list);
1382 list_for_each_entry(bi, &board_list, list)
1383 spi_match_master_to_boardinfo(master, &bi->board_info);
1384 mutex_unlock(&board_lock);
1385
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001386 /* Register devices from the device tree and ACPI */
Anatolij Gustschin12b15e82010-07-27 22:35:58 +02001387 of_register_spi_devices(master);
Mika Westerberg64bee4d2012-11-30 12:37:53 +01001388 acpi_register_spi_devices(master);
David Brownell8ae12a02006-01-08 13:34:19 -08001389done:
1390 return status;
1391}
1392EXPORT_SYMBOL_GPL(spi_register_master);
1393
Mark Brown666d5b42013-08-31 18:50:52 +01001394static void devm_spi_unregister(struct device *dev, void *res)
1395{
1396 spi_unregister_master(*(struct spi_master **)res);
1397}
1398
1399/**
1400 * dev_spi_register_master - register managed SPI master controller
1401 * @dev: device managing SPI master
1402 * @master: initialized master, originally from spi_alloc_master()
1403 * Context: can sleep
1404 *
1405 * Register a SPI device as with spi_register_master() which will
1406 * automatically be unregister
1407 */
1408int devm_spi_register_master(struct device *dev, struct spi_master *master)
1409{
1410 struct spi_master **ptr;
1411 int ret;
1412
1413 ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
1414 if (!ptr)
1415 return -ENOMEM;
1416
1417 ret = spi_register_master(master);
Stephen Warren4b928942013-11-21 16:11:15 -07001418 if (!ret) {
Mark Brown666d5b42013-08-31 18:50:52 +01001419 *ptr = master;
1420 devres_add(dev, ptr);
1421 } else {
1422 devres_free(ptr);
1423 }
1424
1425 return ret;
1426}
1427EXPORT_SYMBOL_GPL(devm_spi_register_master);
1428
David Lamparter34860082010-08-30 23:54:17 +02001429static int __unregister(struct device *dev, void *null)
David Brownell8ae12a02006-01-08 13:34:19 -08001430{
David Lamparter34860082010-08-30 23:54:17 +02001431 spi_unregister_device(to_spi_device(dev));
David Brownell8ae12a02006-01-08 13:34:19 -08001432 return 0;
1433}
1434
1435/**
1436 * spi_unregister_master - unregister SPI master controller
1437 * @master: the master being unregistered
David Brownell33e34dc2007-05-08 00:32:21 -07001438 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001439 *
1440 * This call is used only by SPI master controller drivers, which are the
1441 * only ones directly touching chip registers.
1442 *
1443 * This must be called from context that can sleep.
1444 */
1445void spi_unregister_master(struct spi_master *master)
1446{
Jeff Garzik89fc9a12006-12-06 20:35:35 -08001447 int dummy;
1448
Linus Walleijffbbdd212012-02-22 10:05:38 +01001449 if (master->queued) {
1450 if (spi_destroy_queue(master))
1451 dev_err(&master->dev, "queue remove failed\n");
1452 }
1453
Feng Tang2b9603a2010-08-02 15:52:15 +08001454 mutex_lock(&board_lock);
1455 list_del(&master->list);
1456 mutex_unlock(&board_lock);
1457
Sebastian Andrzej Siewior97dbf372010-12-21 17:24:31 -08001458 dummy = device_for_each_child(&master->dev, NULL, __unregister);
Tony Jones49dce682007-10-16 01:27:48 -07001459 device_unregister(&master->dev);
David Brownell8ae12a02006-01-08 13:34:19 -08001460}
1461EXPORT_SYMBOL_GPL(spi_unregister_master);
1462
Linus Walleijffbbdd212012-02-22 10:05:38 +01001463int spi_master_suspend(struct spi_master *master)
1464{
1465 int ret;
1466
1467 /* Basically no-ops for non-queued masters */
1468 if (!master->queued)
1469 return 0;
1470
1471 ret = spi_stop_queue(master);
1472 if (ret)
1473 dev_err(&master->dev, "queue stop failed\n");
1474
1475 return ret;
1476}
1477EXPORT_SYMBOL_GPL(spi_master_suspend);
1478
1479int spi_master_resume(struct spi_master *master)
1480{
1481 int ret;
1482
1483 if (!master->queued)
1484 return 0;
1485
1486 ret = spi_start_queue(master);
1487 if (ret)
1488 dev_err(&master->dev, "queue restart failed\n");
1489
1490 return ret;
1491}
1492EXPORT_SYMBOL_GPL(spi_master_resume);
1493
Michał Mirosław9f3b7952013-02-01 20:40:17 +01001494static int __spi_master_match(struct device *dev, const void *data)
Dave Young5ed2c832008-01-22 15:14:18 +08001495{
1496 struct spi_master *m;
Michał Mirosław9f3b7952013-02-01 20:40:17 +01001497 const u16 *bus_num = data;
Dave Young5ed2c832008-01-22 15:14:18 +08001498
1499 m = container_of(dev, struct spi_master, dev);
1500 return m->bus_num == *bus_num;
1501}
1502
David Brownell8ae12a02006-01-08 13:34:19 -08001503/**
1504 * spi_busnum_to_master - look up master associated with bus_num
1505 * @bus_num: the master's bus number
David Brownell33e34dc2007-05-08 00:32:21 -07001506 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001507 *
1508 * This call may be used with devices that are registered after
1509 * arch init time. It returns a refcounted pointer to the relevant
1510 * spi_master (which the caller must release), or NULL if there is
1511 * no such master registered.
1512 */
1513struct spi_master *spi_busnum_to_master(u16 bus_num)
1514{
Tony Jones49dce682007-10-16 01:27:48 -07001515 struct device *dev;
Atsushi Nemoto1e9a51d2007-01-26 00:56:54 -08001516 struct spi_master *master = NULL;
David Brownell8ae12a02006-01-08 13:34:19 -08001517
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -04001518 dev = class_find_device(&spi_master_class, NULL, &bus_num,
Dave Young5ed2c832008-01-22 15:14:18 +08001519 __spi_master_match);
1520 if (dev)
1521 master = container_of(dev, struct spi_master, dev);
1522 /* reference got in class_find_device */
Atsushi Nemoto1e9a51d2007-01-26 00:56:54 -08001523 return master;
David Brownell8ae12a02006-01-08 13:34:19 -08001524}
1525EXPORT_SYMBOL_GPL(spi_busnum_to_master);
1526
1527
1528/*-------------------------------------------------------------------------*/
1529
David Brownell7d077192009-06-17 16:26:03 -07001530/* Core methods for SPI master protocol drivers. Some of the
1531 * other core methods are currently defined as inline functions.
1532 */
1533
1534/**
1535 * spi_setup - setup SPI mode and clock rate
1536 * @spi: the device whose settings are being modified
1537 * Context: can sleep, and no requests are queued to the device
1538 *
1539 * SPI protocol drivers may need to update the transfer mode if the
1540 * device doesn't work with its default. They may likewise need
1541 * to update clock rates or word sizes from initial values. This function
1542 * changes those settings, and must be called from a context that can sleep.
1543 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take
1544 * effect the next time the device is selected and data is transferred to
1545 * or from it. When this function returns, the spi device is deselected.
1546 *
1547 * Note that this call will fail if the protocol driver specifies an option
1548 * that the underlying controller or its driver does not support. For
1549 * example, not all hardware supports wire transfers using nine bit words,
1550 * LSB-first wire encoding, or active-high chipselects.
1551 */
1552int spi_setup(struct spi_device *spi)
1553{
David Brownelle7db06b2009-06-17 16:26:04 -07001554 unsigned bad_bits;
Laxman Dewangancaae0702012-11-09 14:35:22 +05301555 int status = 0;
David Brownell7d077192009-06-17 16:26:03 -07001556
wangyuhangf477b7f2013-08-11 18:15:17 +08001557 /* check mode to prevent that DUAL and QUAD set at the same time
1558 */
1559 if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
1560 ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
1561 dev_err(&spi->dev,
1562 "setup: can not select dual and quad at the same time\n");
1563 return -EINVAL;
1564 }
1565 /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
1566 */
1567 if ((spi->mode & SPI_3WIRE) && (spi->mode &
1568 (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)))
1569 return -EINVAL;
David Brownelle7db06b2009-06-17 16:26:04 -07001570 /* help drivers fail *cleanly* when they need options
1571 * that aren't supported with their current master
1572 */
1573 bad_bits = spi->mode & ~spi->master->mode_bits;
1574 if (bad_bits) {
Linus Walleijeb288a12010-10-21 21:06:44 +02001575 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
David Brownelle7db06b2009-06-17 16:26:04 -07001576 bad_bits);
1577 return -EINVAL;
1578 }
1579
David Brownell7d077192009-06-17 16:26:03 -07001580 if (!spi->bits_per_word)
1581 spi->bits_per_word = 8;
1582
Laxman Dewangancaae0702012-11-09 14:35:22 +05301583 if (spi->master->setup)
1584 status = spi->master->setup(spi);
David Brownell7d077192009-06-17 16:26:03 -07001585
Jingoo Han5fe5f052013-10-14 10:31:51 +09001586 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 -07001587 (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
1588 (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
1589 (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
1590 (spi->mode & SPI_3WIRE) ? "3wire, " : "",
1591 (spi->mode & SPI_LOOP) ? "loopback, " : "",
1592 spi->bits_per_word, spi->max_speed_hz,
1593 status);
1594
1595 return status;
1596}
1597EXPORT_SYMBOL_GPL(spi_setup);
1598
Ernst Schwabcf32b712010-06-28 17:49:29 -07001599static int __spi_async(struct spi_device *spi, struct spi_message *message)
1600{
1601 struct spi_master *master = spi->master;
Laxman Dewangane6811d12012-11-09 14:36:45 +05301602 struct spi_transfer *xfer;
Ernst Schwabcf32b712010-06-28 17:49:29 -07001603
Mark Brown56ec1972013-10-07 19:33:53 +01001604 message->spi = spi;
1605
1606 trace_spi_message_submit(message);
1607
Mark Brown24a00132013-07-10 15:05:40 +01001608 if (list_empty(&message->transfers))
1609 return -EINVAL;
1610 if (!message->complete)
1611 return -EINVAL;
1612
Ernst Schwabcf32b712010-06-28 17:49:29 -07001613 /* Half-duplex links include original MicroWire, and ones with
1614 * only one data pin like SPI_3WIRE (switches direction) or where
1615 * either MOSI or MISO is missing. They can also be caused by
1616 * software limitations.
1617 */
1618 if ((master->flags & SPI_MASTER_HALF_DUPLEX)
1619 || (spi->mode & SPI_3WIRE)) {
Ernst Schwabcf32b712010-06-28 17:49:29 -07001620 unsigned flags = master->flags;
1621
1622 list_for_each_entry(xfer, &message->transfers, transfer_list) {
1623 if (xfer->rx_buf && xfer->tx_buf)
1624 return -EINVAL;
1625 if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf)
1626 return -EINVAL;
1627 if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf)
1628 return -EINVAL;
1629 }
1630 }
1631
Laxman Dewangane6811d12012-11-09 14:36:45 +05301632 /**
Laxman Dewangan059b8ff2013-01-05 00:17:14 +05301633 * Set transfer bits_per_word and max speed as spi device default if
1634 * it is not set for this transfer.
wangyuhangf477b7f2013-08-11 18:15:17 +08001635 * Set transfer tx_nbits and rx_nbits as single transfer default
1636 * (SPI_NBITS_SINGLE) if it is not set for this transfer.
Laxman Dewangane6811d12012-11-09 14:36:45 +05301637 */
1638 list_for_each_entry(xfer, &message->transfers, transfer_list) {
Sourav Poddar078726c2013-07-18 15:31:25 +05301639 message->frame_length += xfer->len;
Laxman Dewangane6811d12012-11-09 14:36:45 +05301640 if (!xfer->bits_per_word)
1641 xfer->bits_per_word = spi->bits_per_word;
Gabor Juhos56ede942013-08-14 10:25:28 +02001642 if (!xfer->speed_hz) {
Laxman Dewangan059b8ff2013-01-05 00:17:14 +05301643 xfer->speed_hz = spi->max_speed_hz;
Gabor Juhos56ede942013-08-14 10:25:28 +02001644 if (master->max_speed_hz &&
1645 xfer->speed_hz > master->max_speed_hz)
1646 xfer->speed_hz = master->max_speed_hz;
1647 }
1648
Stephen Warren543bb252013-03-26 20:37:57 -06001649 if (master->bits_per_word_mask) {
1650 /* Only 32 bits fit in the mask */
1651 if (xfer->bits_per_word > 32)
1652 return -EINVAL;
1653 if (!(master->bits_per_word_mask &
1654 BIT(xfer->bits_per_word - 1)))
1655 return -EINVAL;
1656 }
Mark Browna2fd4f92013-07-10 14:57:26 +01001657
1658 if (xfer->speed_hz && master->min_speed_hz &&
1659 xfer->speed_hz < master->min_speed_hz)
1660 return -EINVAL;
1661 if (xfer->speed_hz && master->max_speed_hz &&
1662 xfer->speed_hz > master->max_speed_hz)
wangyuhangd5ee7222013-08-30 18:05:10 +08001663 return -EINVAL;
wangyuhangf477b7f2013-08-11 18:15:17 +08001664
1665 if (xfer->tx_buf && !xfer->tx_nbits)
1666 xfer->tx_nbits = SPI_NBITS_SINGLE;
1667 if (xfer->rx_buf && !xfer->rx_nbits)
1668 xfer->rx_nbits = SPI_NBITS_SINGLE;
1669 /* check transfer tx/rx_nbits:
1670 * 1. keep the value is not out of single, dual and quad
1671 * 2. keep tx/rx_nbits is contained by mode in spi_device
1672 * 3. if SPI_3WIRE, tx/rx_nbits should be in single
1673 */
Sourav Poddardb90a442013-08-22 21:20:48 +05301674 if (xfer->tx_buf) {
1675 if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
1676 xfer->tx_nbits != SPI_NBITS_DUAL &&
1677 xfer->tx_nbits != SPI_NBITS_QUAD)
1678 return -EINVAL;
1679 if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
1680 !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
1681 return -EINVAL;
1682 if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
1683 !(spi->mode & SPI_TX_QUAD))
1684 return -EINVAL;
1685 if ((spi->mode & SPI_3WIRE) &&
1686 (xfer->tx_nbits != SPI_NBITS_SINGLE))
1687 return -EINVAL;
1688 }
wangyuhangf477b7f2013-08-11 18:15:17 +08001689 /* check transfer rx_nbits */
Sourav Poddardb90a442013-08-22 21:20:48 +05301690 if (xfer->rx_buf) {
1691 if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
1692 xfer->rx_nbits != SPI_NBITS_DUAL &&
1693 xfer->rx_nbits != SPI_NBITS_QUAD)
1694 return -EINVAL;
1695 if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
1696 !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
1697 return -EINVAL;
1698 if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
1699 !(spi->mode & SPI_RX_QUAD))
1700 return -EINVAL;
1701 if ((spi->mode & SPI_3WIRE) &&
1702 (xfer->rx_nbits != SPI_NBITS_SINGLE))
1703 return -EINVAL;
1704 }
Laxman Dewangane6811d12012-11-09 14:36:45 +05301705 }
1706
Ernst Schwabcf32b712010-06-28 17:49:29 -07001707 message->status = -EINPROGRESS;
1708 return master->transfer(spi, message);
1709}
1710
David Brownell568d0692009-09-22 16:46:18 -07001711/**
1712 * spi_async - asynchronous SPI transfer
1713 * @spi: device with which data will be exchanged
1714 * @message: describes the data transfers, including completion callback
1715 * Context: any (irqs may be blocked, etc)
1716 *
1717 * This call may be used in_irq and other contexts which can't sleep,
1718 * as well as from task contexts which can sleep.
1719 *
1720 * The completion callback is invoked in a context which can't sleep.
1721 * Before that invocation, the value of message->status is undefined.
1722 * When the callback is issued, message->status holds either zero (to
1723 * indicate complete success) or a negative error code. After that
1724 * callback returns, the driver which issued the transfer request may
1725 * deallocate the associated memory; it's no longer in use by any SPI
1726 * core or controller driver code.
1727 *
1728 * Note that although all messages to a spi_device are handled in
1729 * FIFO order, messages may go to different devices in other orders.
1730 * Some device might be higher priority, or have various "hard" access
1731 * time requirements, for example.
1732 *
1733 * On detection of any fault during the transfer, processing of
1734 * the entire message is aborted, and the device is deselected.
1735 * Until returning from the associated message completion callback,
1736 * no other spi_message queued to that device will be processed.
1737 * (This rule applies equally to all the synchronous transfer calls,
1738 * which are wrappers around this core asynchronous primitive.)
1739 */
1740int spi_async(struct spi_device *spi, struct spi_message *message)
1741{
1742 struct spi_master *master = spi->master;
Ernst Schwabcf32b712010-06-28 17:49:29 -07001743 int ret;
1744 unsigned long flags;
David Brownell568d0692009-09-22 16:46:18 -07001745
Ernst Schwabcf32b712010-06-28 17:49:29 -07001746 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
David Brownell568d0692009-09-22 16:46:18 -07001747
Ernst Schwabcf32b712010-06-28 17:49:29 -07001748 if (master->bus_lock_flag)
1749 ret = -EBUSY;
1750 else
1751 ret = __spi_async(spi, message);
David Brownell568d0692009-09-22 16:46:18 -07001752
Ernst Schwabcf32b712010-06-28 17:49:29 -07001753 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
1754
1755 return ret;
David Brownell568d0692009-09-22 16:46:18 -07001756}
1757EXPORT_SYMBOL_GPL(spi_async);
1758
Ernst Schwabcf32b712010-06-28 17:49:29 -07001759/**
1760 * spi_async_locked - version of spi_async with exclusive bus usage
1761 * @spi: device with which data will be exchanged
1762 * @message: describes the data transfers, including completion callback
1763 * Context: any (irqs may be blocked, etc)
1764 *
1765 * This call may be used in_irq and other contexts which can't sleep,
1766 * as well as from task contexts which can sleep.
1767 *
1768 * The completion callback is invoked in a context which can't sleep.
1769 * Before that invocation, the value of message->status is undefined.
1770 * When the callback is issued, message->status holds either zero (to
1771 * indicate complete success) or a negative error code. After that
1772 * callback returns, the driver which issued the transfer request may
1773 * deallocate the associated memory; it's no longer in use by any SPI
1774 * core or controller driver code.
1775 *
1776 * Note that although all messages to a spi_device are handled in
1777 * FIFO order, messages may go to different devices in other orders.
1778 * Some device might be higher priority, or have various "hard" access
1779 * time requirements, for example.
1780 *
1781 * On detection of any fault during the transfer, processing of
1782 * the entire message is aborted, and the device is deselected.
1783 * Until returning from the associated message completion callback,
1784 * no other spi_message queued to that device will be processed.
1785 * (This rule applies equally to all the synchronous transfer calls,
1786 * which are wrappers around this core asynchronous primitive.)
1787 */
1788int spi_async_locked(struct spi_device *spi, struct spi_message *message)
1789{
1790 struct spi_master *master = spi->master;
1791 int ret;
1792 unsigned long flags;
1793
1794 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
1795
1796 ret = __spi_async(spi, message);
1797
1798 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
1799
1800 return ret;
1801
1802}
1803EXPORT_SYMBOL_GPL(spi_async_locked);
1804
David Brownell7d077192009-06-17 16:26:03 -07001805
1806/*-------------------------------------------------------------------------*/
1807
1808/* Utility methods for SPI master protocol drivers, layered on
1809 * top of the core. Some other utility methods are defined as
1810 * inline functions.
1811 */
1812
Andrew Morton5d870c82006-01-11 11:23:49 -08001813static void spi_complete(void *arg)
1814{
1815 complete(arg);
1816}
1817
Ernst Schwabcf32b712010-06-28 17:49:29 -07001818static int __spi_sync(struct spi_device *spi, struct spi_message *message,
1819 int bus_locked)
1820{
1821 DECLARE_COMPLETION_ONSTACK(done);
1822 int status;
1823 struct spi_master *master = spi->master;
1824
1825 message->complete = spi_complete;
1826 message->context = &done;
1827
1828 if (!bus_locked)
1829 mutex_lock(&master->bus_lock_mutex);
1830
1831 status = spi_async_locked(spi, message);
1832
1833 if (!bus_locked)
1834 mutex_unlock(&master->bus_lock_mutex);
1835
1836 if (status == 0) {
1837 wait_for_completion(&done);
1838 status = message->status;
1839 }
1840 message->context = NULL;
1841 return status;
1842}
1843
David Brownell8ae12a02006-01-08 13:34:19 -08001844/**
1845 * spi_sync - blocking/synchronous SPI data transfers
1846 * @spi: device with which data will be exchanged
1847 * @message: describes the data transfers
David Brownell33e34dc2007-05-08 00:32:21 -07001848 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001849 *
1850 * This call may only be used from a context that may sleep. The sleep
1851 * is non-interruptible, and has no timeout. Low-overhead controller
1852 * drivers may DMA directly into and out of the message buffers.
1853 *
1854 * Note that the SPI device's chip select is active during the message,
1855 * and then is normally disabled between messages. Drivers for some
1856 * frequently-used devices may want to minimize costs of selecting a chip,
1857 * by leaving it selected in anticipation that the next message will go
1858 * to the same chip. (That may increase power usage.)
1859 *
David Brownell0c868462006-01-08 13:34:25 -08001860 * Also, the caller is guaranteeing that the memory associated with the
1861 * message will not be freed before this call returns.
1862 *
Marc Pignat9b938b72007-12-04 23:45:10 -08001863 * It returns zero on success, else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001864 */
1865int spi_sync(struct spi_device *spi, struct spi_message *message)
1866{
Ernst Schwabcf32b712010-06-28 17:49:29 -07001867 return __spi_sync(spi, message, 0);
David Brownell8ae12a02006-01-08 13:34:19 -08001868}
1869EXPORT_SYMBOL_GPL(spi_sync);
1870
Ernst Schwabcf32b712010-06-28 17:49:29 -07001871/**
1872 * spi_sync_locked - version of spi_sync with exclusive bus usage
1873 * @spi: device with which data will be exchanged
1874 * @message: describes the data transfers
1875 * Context: can sleep
1876 *
1877 * This call may only be used from a context that may sleep. The sleep
1878 * is non-interruptible, and has no timeout. Low-overhead controller
1879 * drivers may DMA directly into and out of the message buffers.
1880 *
1881 * This call should be used by drivers that require exclusive access to the
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001882 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
Ernst Schwabcf32b712010-06-28 17:49:29 -07001883 * be released by a spi_bus_unlock call when the exclusive access is over.
1884 *
1885 * It returns zero on success, else a negative error code.
1886 */
1887int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
1888{
1889 return __spi_sync(spi, message, 1);
1890}
1891EXPORT_SYMBOL_GPL(spi_sync_locked);
1892
1893/**
1894 * spi_bus_lock - obtain a lock for exclusive SPI bus usage
1895 * @master: SPI bus master that should be locked for exclusive bus access
1896 * Context: can sleep
1897 *
1898 * This call may only be used from a context that may sleep. The sleep
1899 * is non-interruptible, and has no timeout.
1900 *
1901 * This call should be used by drivers that require exclusive access to the
1902 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
1903 * exclusive access is over. Data transfer must be done by spi_sync_locked
1904 * and spi_async_locked calls when the SPI bus lock is held.
1905 *
1906 * It returns zero on success, else a negative error code.
1907 */
1908int spi_bus_lock(struct spi_master *master)
1909{
1910 unsigned long flags;
1911
1912 mutex_lock(&master->bus_lock_mutex);
1913
1914 spin_lock_irqsave(&master->bus_lock_spinlock, flags);
1915 master->bus_lock_flag = 1;
1916 spin_unlock_irqrestore(&master->bus_lock_spinlock, flags);
1917
1918 /* mutex remains locked until spi_bus_unlock is called */
1919
1920 return 0;
1921}
1922EXPORT_SYMBOL_GPL(spi_bus_lock);
1923
1924/**
1925 * spi_bus_unlock - release the lock for exclusive SPI bus usage
1926 * @master: SPI bus master that was locked for exclusive bus access
1927 * Context: can sleep
1928 *
1929 * This call may only be used from a context that may sleep. The sleep
1930 * is non-interruptible, and has no timeout.
1931 *
1932 * This call releases an SPI bus lock previously obtained by an spi_bus_lock
1933 * call.
1934 *
1935 * It returns zero on success, else a negative error code.
1936 */
1937int spi_bus_unlock(struct spi_master *master)
1938{
1939 master->bus_lock_flag = 0;
1940
1941 mutex_unlock(&master->bus_lock_mutex);
1942
1943 return 0;
1944}
1945EXPORT_SYMBOL_GPL(spi_bus_unlock);
1946
David Brownella9948b62006-04-02 10:37:40 -08001947/* portable code must never pass more than 32 bytes */
Jingoo Han5fe5f052013-10-14 10:31:51 +09001948#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
David Brownell8ae12a02006-01-08 13:34:19 -08001949
1950static u8 *buf;
1951
1952/**
1953 * spi_write_then_read - SPI synchronous write followed by read
1954 * @spi: device with which data will be exchanged
1955 * @txbuf: data to be written (need not be dma-safe)
1956 * @n_tx: size of txbuf, in bytes
Jiri Pirko27570492009-06-17 16:26:06 -07001957 * @rxbuf: buffer into which data will be read (need not be dma-safe)
1958 * @n_rx: size of rxbuf, in bytes
David Brownell33e34dc2007-05-08 00:32:21 -07001959 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001960 *
1961 * This performs a half duplex MicroWire style transaction with the
1962 * device, sending txbuf and then reading rxbuf. The return value
1963 * is zero for success, else a negative errno status code.
David Brownellb8852442006-01-08 13:34:23 -08001964 * This call may only be used from a context that may sleep.
David Brownell8ae12a02006-01-08 13:34:19 -08001965 *
David Brownell0c868462006-01-08 13:34:25 -08001966 * Parameters to this routine are always copied using a small buffer;
David Brownell33e34dc2007-05-08 00:32:21 -07001967 * portable code should never use this for more than 32 bytes.
1968 * Performance-sensitive or bulk transfer code should instead use
David Brownell0c868462006-01-08 13:34:25 -08001969 * spi_{async,sync}() calls with dma-safe buffers.
David Brownell8ae12a02006-01-08 13:34:19 -08001970 */
1971int spi_write_then_read(struct spi_device *spi,
Mark Brown0c4a1592011-05-11 00:09:30 +02001972 const void *txbuf, unsigned n_tx,
1973 void *rxbuf, unsigned n_rx)
David Brownell8ae12a02006-01-08 13:34:19 -08001974{
David Brownell068f4072007-12-04 23:45:09 -08001975 static DEFINE_MUTEX(lock);
David Brownell8ae12a02006-01-08 13:34:19 -08001976
1977 int status;
1978 struct spi_message message;
David Brownellbdff5492009-04-13 14:39:57 -07001979 struct spi_transfer x[2];
David Brownell8ae12a02006-01-08 13:34:19 -08001980 u8 *local_buf;
1981
Mark Brownb3a223e2012-12-02 12:54:25 +09001982 /* Use preallocated DMA-safe buffer if we can. We can't avoid
1983 * copying here, (as a pure convenience thing), but we can
1984 * keep heap costs out of the hot path unless someone else is
1985 * using the pre-allocated buffer or the transfer is too large.
David Brownell8ae12a02006-01-08 13:34:19 -08001986 */
Mark Brownb3a223e2012-12-02 12:54:25 +09001987 if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
Mark Brown2cd94c82013-01-27 14:35:04 +08001988 local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
1989 GFP_KERNEL | GFP_DMA);
Mark Brownb3a223e2012-12-02 12:54:25 +09001990 if (!local_buf)
1991 return -ENOMEM;
1992 } else {
1993 local_buf = buf;
1994 }
David Brownell8ae12a02006-01-08 13:34:19 -08001995
Vitaly Wool8275c642006-01-08 13:34:28 -08001996 spi_message_init(&message);
Jingoo Han5fe5f052013-10-14 10:31:51 +09001997 memset(x, 0, sizeof(x));
David Brownellbdff5492009-04-13 14:39:57 -07001998 if (n_tx) {
1999 x[0].len = n_tx;
2000 spi_message_add_tail(&x[0], &message);
2001 }
2002 if (n_rx) {
2003 x[1].len = n_rx;
2004 spi_message_add_tail(&x[1], &message);
2005 }
Vitaly Wool8275c642006-01-08 13:34:28 -08002006
David Brownell8ae12a02006-01-08 13:34:19 -08002007 memcpy(local_buf, txbuf, n_tx);
David Brownellbdff5492009-04-13 14:39:57 -07002008 x[0].tx_buf = local_buf;
2009 x[1].rx_buf = local_buf + n_tx;
David Brownell8ae12a02006-01-08 13:34:19 -08002010
2011 /* do the i/o */
David Brownell8ae12a02006-01-08 13:34:19 -08002012 status = spi_sync(spi, &message);
Marc Pignat9b938b72007-12-04 23:45:10 -08002013 if (status == 0)
David Brownellbdff5492009-04-13 14:39:57 -07002014 memcpy(rxbuf, x[1].rx_buf, n_rx);
David Brownell8ae12a02006-01-08 13:34:19 -08002015
David Brownellbdff5492009-04-13 14:39:57 -07002016 if (x[0].tx_buf == buf)
David Brownell068f4072007-12-04 23:45:09 -08002017 mutex_unlock(&lock);
David Brownell8ae12a02006-01-08 13:34:19 -08002018 else
2019 kfree(local_buf);
2020
2021 return status;
2022}
2023EXPORT_SYMBOL_GPL(spi_write_then_read);
2024
2025/*-------------------------------------------------------------------------*/
2026
2027static int __init spi_init(void)
2028{
David Brownellb8852442006-01-08 13:34:23 -08002029 int status;
David Brownell8ae12a02006-01-08 13:34:19 -08002030
Christoph Lametere94b1762006-12-06 20:33:17 -08002031 buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
David Brownellb8852442006-01-08 13:34:23 -08002032 if (!buf) {
2033 status = -ENOMEM;
2034 goto err0;
2035 }
2036
2037 status = bus_register(&spi_bus_type);
2038 if (status < 0)
2039 goto err1;
2040
2041 status = class_register(&spi_master_class);
2042 if (status < 0)
2043 goto err2;
David Brownell8ae12a02006-01-08 13:34:19 -08002044 return 0;
David Brownellb8852442006-01-08 13:34:23 -08002045
2046err2:
2047 bus_unregister(&spi_bus_type);
2048err1:
2049 kfree(buf);
2050 buf = NULL;
2051err0:
2052 return status;
David Brownell8ae12a02006-01-08 13:34:19 -08002053}
David Brownellb8852442006-01-08 13:34:23 -08002054
David Brownell8ae12a02006-01-08 13:34:19 -08002055/* board_info is normally registered in arch_initcall(),
2056 * but even essential drivers wait till later
David Brownellb8852442006-01-08 13:34:23 -08002057 *
2058 * REVISIT only boardinfo really needs static linking. the rest (device and
2059 * driver registration) _could_ be dynamically linked (modular) ... costs
2060 * include needing to have boardinfo data structures be much more public.
David Brownell8ae12a02006-01-08 13:34:19 -08002061 */
David Brownell673c0c02008-10-15 22:02:46 -07002062postcore_initcall(spi_init);
David Brownell8ae12a02006-01-08 13:34:19 -08002063