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Commit | Line | Data |
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8ae12a0d | 1 | /* |
ca632f55 | 2 | * SPI init/core code |
8ae12a0d DB |
3 | * |
4 | * Copyright (C) 2005 David Brownell | |
d57a4282 | 5 | * Copyright (C) 2008 Secret Lab Technologies Ltd. |
8ae12a0d DB |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
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 | ||
8ae12a0d | 22 | #include <linux/kernel.h> |
d57a4282 | 23 | #include <linux/kmod.h> |
8ae12a0d DB |
24 | #include <linux/device.h> |
25 | #include <linux/init.h> | |
26 | #include <linux/cache.h> | |
94040828 | 27 | #include <linux/mutex.h> |
2b7a32f7 | 28 | #include <linux/of_device.h> |
d57a4282 | 29 | #include <linux/of_irq.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
e0626e38 | 31 | #include <linux/mod_devicetable.h> |
8ae12a0d | 32 | #include <linux/spi/spi.h> |
74317984 | 33 | #include <linux/of_gpio.h> |
3ae22e8c | 34 | #include <linux/pm_runtime.h> |
025ed130 | 35 | #include <linux/export.h> |
8bd75c77 | 36 | #include <linux/sched/rt.h> |
ffbbdd21 LW |
37 | #include <linux/delay.h> |
38 | #include <linux/kthread.h> | |
64bee4d2 MW |
39 | #include <linux/ioport.h> |
40 | #include <linux/acpi.h> | |
8ae12a0d | 41 | |
56ec1978 MB |
42 | #define CREATE_TRACE_POINTS |
43 | #include <trace/events/spi.h> | |
44 | ||
8ae12a0d DB |
45 | static void spidev_release(struct device *dev) |
46 | { | |
0ffa0285 | 47 | struct spi_device *spi = to_spi_device(dev); |
8ae12a0d DB |
48 | |
49 | /* spi masters may cleanup for released devices */ | |
50 | if (spi->master->cleanup) | |
51 | spi->master->cleanup(spi); | |
52 | ||
0c868461 | 53 | spi_master_put(spi->master); |
07a389fe | 54 | kfree(spi); |
8ae12a0d DB |
55 | } |
56 | ||
57 | static ssize_t | |
58 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) | |
59 | { | |
60 | const struct spi_device *spi = to_spi_device(dev); | |
61 | ||
d8e328b3 | 62 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d | 63 | } |
aa7da564 | 64 | static DEVICE_ATTR_RO(modalias); |
8ae12a0d | 65 | |
aa7da564 GKH |
66 | static struct attribute *spi_dev_attrs[] = { |
67 | &dev_attr_modalias.attr, | |
68 | NULL, | |
8ae12a0d | 69 | }; |
aa7da564 | 70 | ATTRIBUTE_GROUPS(spi_dev); |
8ae12a0d DB |
71 | |
72 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, | |
73 | * and the sysfs version makes coldplug work too. | |
74 | */ | |
75 | ||
75368bf6 AV |
76 | static 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 | ||
87 | const 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 | } | |
93 | EXPORT_SYMBOL_GPL(spi_get_device_id); | |
94 | ||
8ae12a0d DB |
95 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
96 | { | |
97 | const struct spi_device *spi = to_spi_device(dev); | |
75368bf6 AV |
98 | const struct spi_driver *sdrv = to_spi_driver(drv); |
99 | ||
2b7a32f7 SA |
100 | /* Attempt an OF style match */ |
101 | if (of_driver_match_device(dev, drv)) | |
102 | return 1; | |
103 | ||
64bee4d2 MW |
104 | /* Then try ACPI */ |
105 | if (acpi_driver_match_device(dev, drv)) | |
106 | return 1; | |
107 | ||
75368bf6 AV |
108 | if (sdrv->id_table) |
109 | return !!spi_match_id(sdrv->id_table, spi); | |
8ae12a0d | 110 | |
35f74fca | 111 | return strcmp(spi->modalias, drv->name) == 0; |
8ae12a0d DB |
112 | } |
113 | ||
7eff2e7a | 114 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
8ae12a0d DB |
115 | { |
116 | const struct spi_device *spi = to_spi_device(dev); | |
117 | ||
e0626e38 | 118 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d DB |
119 | return 0; |
120 | } | |
121 | ||
3ae22e8c MB |
122 | #ifdef CONFIG_PM_SLEEP |
123 | static int spi_legacy_suspend(struct device *dev, pm_message_t message) | |
8ae12a0d | 124 | { |
3c72426f | 125 | int value = 0; |
b885244e | 126 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 127 | |
8ae12a0d | 128 | /* suspend will stop irqs and dma; no more i/o */ |
3c72426f DB |
129 | 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 | } | |
8ae12a0d DB |
135 | return value; |
136 | } | |
137 | ||
3ae22e8c | 138 | static int spi_legacy_resume(struct device *dev) |
8ae12a0d | 139 | { |
3c72426f | 140 | int value = 0; |
b885244e | 141 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 142 | |
8ae12a0d | 143 | /* resume may restart the i/o queue */ |
3c72426f DB |
144 | 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 | } | |
8ae12a0d DB |
150 | return value; |
151 | } | |
152 | ||
3ae22e8c MB |
153 | static 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 | ||
163 | static 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 | ||
173 | static 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 | ||
183 | static 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 | ||
193 | static 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 | ||
203 | static 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 | } | |
8ae12a0d | 212 | #else |
3ae22e8c MB |
213 | #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 | |
8ae12a0d DB |
219 | #endif |
220 | ||
3ae22e8c MB |
221 | static 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, | |
45f0a85c | 231 | NULL |
3ae22e8c MB |
232 | ) |
233 | }; | |
234 | ||
8ae12a0d DB |
235 | struct bus_type spi_bus_type = { |
236 | .name = "spi", | |
aa7da564 | 237 | .dev_groups = spi_dev_groups, |
8ae12a0d DB |
238 | .match = spi_match_device, |
239 | .uevent = spi_uevent, | |
3ae22e8c | 240 | .pm = &spi_pm, |
8ae12a0d DB |
241 | }; |
242 | EXPORT_SYMBOL_GPL(spi_bus_type); | |
243 | ||
b885244e DB |
244 | |
245 | static int spi_drv_probe(struct device *dev) | |
246 | { | |
247 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
248 | ||
249 | return sdrv->probe(to_spi_device(dev)); | |
250 | } | |
251 | ||
252 | static int spi_drv_remove(struct device *dev) | |
253 | { | |
254 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
255 | ||
256 | return sdrv->remove(to_spi_device(dev)); | |
257 | } | |
258 | ||
259 | static void spi_drv_shutdown(struct device *dev) | |
260 | { | |
261 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
262 | ||
263 | sdrv->shutdown(to_spi_device(dev)); | |
264 | } | |
265 | ||
33e34dc6 DB |
266 | /** |
267 | * spi_register_driver - register a SPI driver | |
268 | * @sdrv: the driver to register | |
269 | * Context: can sleep | |
270 | */ | |
b885244e DB |
271 | int spi_register_driver(struct spi_driver *sdrv) |
272 | { | |
273 | sdrv->driver.bus = &spi_bus_type; | |
274 | if (sdrv->probe) | |
275 | sdrv->driver.probe = spi_drv_probe; | |
276 | if (sdrv->remove) | |
277 | sdrv->driver.remove = spi_drv_remove; | |
278 | if (sdrv->shutdown) | |
279 | sdrv->driver.shutdown = spi_drv_shutdown; | |
280 | return driver_register(&sdrv->driver); | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(spi_register_driver); | |
283 | ||
8ae12a0d DB |
284 | /*-------------------------------------------------------------------------*/ |
285 | ||
286 | /* SPI devices should normally not be created by SPI device drivers; that | |
287 | * would make them board-specific. Similarly with SPI master drivers. | |
288 | * Device registration normally goes into like arch/.../mach.../board-YYY.c | |
289 | * with other readonly (flashable) information about mainboard devices. | |
290 | */ | |
291 | ||
292 | struct boardinfo { | |
293 | struct list_head list; | |
2b9603a0 | 294 | struct spi_board_info board_info; |
8ae12a0d DB |
295 | }; |
296 | ||
297 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
298 | static LIST_HEAD(spi_master_list); |
299 | ||
300 | /* | |
301 | * Used to protect add/del opertion for board_info list and | |
302 | * spi_master list, and their matching process | |
303 | */ | |
94040828 | 304 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 305 | |
dc87c98e GL |
306 | /** |
307 | * spi_alloc_device - Allocate a new SPI device | |
308 | * @master: Controller to which device is connected | |
309 | * Context: can sleep | |
310 | * | |
311 | * Allows a driver to allocate and initialize a spi_device without | |
312 | * registering it immediately. This allows a driver to directly | |
313 | * fill the spi_device with device parameters before calling | |
314 | * spi_add_device() on it. | |
315 | * | |
316 | * Caller is responsible to call spi_add_device() on the returned | |
317 | * spi_device structure to add it to the SPI master. If the caller | |
318 | * needs to discard the spi_device without adding it, then it should | |
319 | * call spi_dev_put() on it. | |
320 | * | |
321 | * Returns a pointer to the new device, or NULL. | |
322 | */ | |
323 | struct spi_device *spi_alloc_device(struct spi_master *master) | |
324 | { | |
325 | struct spi_device *spi; | |
326 | struct device *dev = master->dev.parent; | |
327 | ||
328 | if (!spi_master_get(master)) | |
329 | return NULL; | |
330 | ||
5fe5f05e | 331 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e GL |
332 | if (!spi) { |
333 | dev_err(dev, "cannot alloc spi_device\n"); | |
334 | spi_master_put(master); | |
335 | return NULL; | |
336 | } | |
337 | ||
338 | spi->master = master; | |
178db7d3 | 339 | spi->dev.parent = &master->dev; |
dc87c98e GL |
340 | spi->dev.bus = &spi_bus_type; |
341 | spi->dev.release = spidev_release; | |
446411e1 | 342 | spi->cs_gpio = -ENOENT; |
dc87c98e GL |
343 | device_initialize(&spi->dev); |
344 | return spi; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
347 | ||
348 | /** | |
349 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
350 | * @spi: spi_device to register | |
351 | * | |
352 | * Companion function to spi_alloc_device. Devices allocated with | |
353 | * spi_alloc_device can be added onto the spi bus with this function. | |
354 | * | |
e48880e0 | 355 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
356 | */ |
357 | int spi_add_device(struct spi_device *spi) | |
358 | { | |
e48880e0 | 359 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
360 | struct spi_master *master = spi->master; |
361 | struct device *dev = master->dev.parent; | |
8ec130a0 | 362 | struct device *d; |
dc87c98e GL |
363 | int status; |
364 | ||
365 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 366 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
367 | dev_err(dev, "cs%d >= max %d\n", |
368 | spi->chip_select, | |
74317984 | 369 | master->num_chipselect); |
dc87c98e GL |
370 | return -EINVAL; |
371 | } | |
372 | ||
373 | /* Set the bus ID string */ | |
35f74fca | 374 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), |
dc87c98e GL |
375 | spi->chip_select); |
376 | ||
e48880e0 DB |
377 | |
378 | /* We need to make sure there's no other device with this | |
379 | * chipselect **BEFORE** we call setup(), else we'll trash | |
380 | * its configuration. Lock against concurrent add() calls. | |
381 | */ | |
382 | mutex_lock(&spi_add_lock); | |
383 | ||
8ec130a0 RT |
384 | d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)); |
385 | if (d != NULL) { | |
e48880e0 DB |
386 | dev_err(dev, "chipselect %d already in use\n", |
387 | spi->chip_select); | |
8ec130a0 | 388 | put_device(d); |
e48880e0 DB |
389 | status = -EBUSY; |
390 | goto done; | |
391 | } | |
392 | ||
74317984 JCPV |
393 | if (master->cs_gpios) |
394 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
395 | ||
e48880e0 DB |
396 | /* Drivers may modify this initial i/o setup, but will |
397 | * normally rely on the device being setup. Devices | |
398 | * using SPI_CS_HIGH can't coexist well otherwise... | |
399 | */ | |
7d077197 | 400 | status = spi_setup(spi); |
dc87c98e | 401 | if (status < 0) { |
eb288a1f LW |
402 | dev_err(dev, "can't setup %s, status %d\n", |
403 | dev_name(&spi->dev), status); | |
e48880e0 | 404 | goto done; |
dc87c98e GL |
405 | } |
406 | ||
e48880e0 | 407 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 408 | status = device_add(&spi->dev); |
e48880e0 | 409 | if (status < 0) |
eb288a1f LW |
410 | dev_err(dev, "can't add %s, status %d\n", |
411 | dev_name(&spi->dev), status); | |
e48880e0 | 412 | else |
35f74fca | 413 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 414 | |
e48880e0 DB |
415 | done: |
416 | mutex_unlock(&spi_add_lock); | |
417 | return status; | |
dc87c98e GL |
418 | } |
419 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 420 | |
33e34dc6 DB |
421 | /** |
422 | * spi_new_device - instantiate one new SPI device | |
423 | * @master: Controller to which device is connected | |
424 | * @chip: Describes the SPI device | |
425 | * Context: can sleep | |
426 | * | |
427 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
428 | * after board init creates the hard-wired devices. Some development |
429 | * platforms may not be able to use spi_register_board_info though, and | |
430 | * this is exported so that for example a USB or parport based adapter | |
431 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 DB |
432 | * |
433 | * Returns the new device, or NULL. | |
8ae12a0d | 434 | */ |
e9d5a461 AB |
435 | struct spi_device *spi_new_device(struct spi_master *master, |
436 | struct spi_board_info *chip) | |
8ae12a0d DB |
437 | { |
438 | struct spi_device *proxy; | |
8ae12a0d DB |
439 | int status; |
440 | ||
082c8cb4 DB |
441 | /* NOTE: caller did any chip->bus_num checks necessary. |
442 | * | |
443 | * Also, unless we change the return value convention to use | |
444 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
445 | * suggests syslogged diagnostics are best here (ugh). | |
446 | */ | |
447 | ||
dc87c98e GL |
448 | proxy = spi_alloc_device(master); |
449 | if (!proxy) | |
8ae12a0d DB |
450 | return NULL; |
451 | ||
102eb975 GL |
452 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
453 | ||
8ae12a0d DB |
454 | proxy->chip_select = chip->chip_select; |
455 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 456 | proxy->mode = chip->mode; |
8ae12a0d | 457 | proxy->irq = chip->irq; |
102eb975 | 458 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
459 | proxy->dev.platform_data = (void *) chip->platform_data; |
460 | proxy->controller_data = chip->controller_data; | |
461 | proxy->controller_state = NULL; | |
8ae12a0d | 462 | |
dc87c98e | 463 | status = spi_add_device(proxy); |
8ae12a0d | 464 | if (status < 0) { |
dc87c98e GL |
465 | spi_dev_put(proxy); |
466 | return NULL; | |
8ae12a0d DB |
467 | } |
468 | ||
8ae12a0d DB |
469 | return proxy; |
470 | } | |
471 | EXPORT_SYMBOL_GPL(spi_new_device); | |
472 | ||
2b9603a0 FT |
473 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
474 | struct spi_board_info *bi) | |
475 | { | |
476 | struct spi_device *dev; | |
477 | ||
478 | if (master->bus_num != bi->bus_num) | |
479 | return; | |
480 | ||
481 | dev = spi_new_device(master, bi); | |
482 | if (!dev) | |
483 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
484 | bi->modalias); | |
485 | } | |
486 | ||
33e34dc6 DB |
487 | /** |
488 | * spi_register_board_info - register SPI devices for a given board | |
489 | * @info: array of chip descriptors | |
490 | * @n: how many descriptors are provided | |
491 | * Context: can sleep | |
492 | * | |
8ae12a0d DB |
493 | * Board-specific early init code calls this (probably during arch_initcall) |
494 | * with segments of the SPI device table. Any device nodes are created later, | |
495 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
496 | * this table of devices forever, so that reloading a controller driver will | |
497 | * not make Linux forget about these hard-wired devices. | |
498 | * | |
499 | * Other code can also call this, e.g. a particular add-on board might provide | |
500 | * SPI devices through its expansion connector, so code initializing that board | |
501 | * would naturally declare its SPI devices. | |
502 | * | |
503 | * The board info passed can safely be __initdata ... but be careful of | |
504 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
505 | */ | |
fd4a319b | 506 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 507 | { |
2b9603a0 FT |
508 | struct boardinfo *bi; |
509 | int i; | |
8ae12a0d | 510 | |
2b9603a0 | 511 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
512 | if (!bi) |
513 | return -ENOMEM; | |
8ae12a0d | 514 | |
2b9603a0 FT |
515 | for (i = 0; i < n; i++, bi++, info++) { |
516 | struct spi_master *master; | |
8ae12a0d | 517 | |
2b9603a0 FT |
518 | memcpy(&bi->board_info, info, sizeof(*info)); |
519 | mutex_lock(&board_lock); | |
520 | list_add_tail(&bi->list, &board_list); | |
521 | list_for_each_entry(master, &spi_master_list, list) | |
522 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
523 | mutex_unlock(&board_lock); | |
8ae12a0d | 524 | } |
2b9603a0 FT |
525 | |
526 | return 0; | |
8ae12a0d DB |
527 | } |
528 | ||
529 | /*-------------------------------------------------------------------------*/ | |
530 | ||
b158935f MB |
531 | static void spi_set_cs(struct spi_device *spi, bool enable) |
532 | { | |
533 | if (spi->mode & SPI_CS_HIGH) | |
534 | enable = !enable; | |
535 | ||
536 | if (spi->cs_gpio >= 0) | |
537 | gpio_set_value(spi->cs_gpio, !enable); | |
538 | else if (spi->master->set_cs) | |
539 | spi->master->set_cs(spi, !enable); | |
540 | } | |
541 | ||
542 | /* | |
543 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
544 | * | |
545 | * This is a standard implementation of transfer_one_message() for | |
546 | * drivers which impelment a transfer_one() operation. It provides | |
547 | * standard handling of delays and chip select management. | |
548 | */ | |
549 | static int spi_transfer_one_message(struct spi_master *master, | |
550 | struct spi_message *msg) | |
551 | { | |
552 | struct spi_transfer *xfer; | |
553 | bool cur_cs = true; | |
554 | bool keep_cs = false; | |
555 | int ret = 0; | |
556 | ||
557 | spi_set_cs(msg->spi, true); | |
558 | ||
559 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
560 | trace_spi_transfer_start(msg, xfer); | |
561 | ||
562 | INIT_COMPLETION(master->xfer_completion); | |
563 | ||
564 | ret = master->transfer_one(master, msg->spi, xfer); | |
565 | if (ret < 0) { | |
566 | dev_err(&msg->spi->dev, | |
567 | "SPI transfer failed: %d\n", ret); | |
568 | goto out; | |
569 | } | |
570 | ||
571 | if (ret > 0) | |
572 | wait_for_completion(&master->xfer_completion); | |
573 | ||
574 | trace_spi_transfer_stop(msg, xfer); | |
575 | ||
576 | if (msg->status != -EINPROGRESS) | |
577 | goto out; | |
578 | ||
579 | if (xfer->delay_usecs) | |
580 | udelay(xfer->delay_usecs); | |
581 | ||
582 | if (xfer->cs_change) { | |
583 | if (list_is_last(&xfer->transfer_list, | |
584 | &msg->transfers)) { | |
585 | keep_cs = true; | |
586 | } else { | |
587 | cur_cs = !cur_cs; | |
588 | spi_set_cs(msg->spi, cur_cs); | |
589 | } | |
590 | } | |
591 | ||
592 | msg->actual_length += xfer->len; | |
593 | } | |
594 | ||
595 | out: | |
596 | if (ret != 0 || !keep_cs) | |
597 | spi_set_cs(msg->spi, false); | |
598 | ||
599 | if (msg->status == -EINPROGRESS) | |
600 | msg->status = ret; | |
601 | ||
602 | spi_finalize_current_message(master); | |
603 | ||
604 | return ret; | |
605 | } | |
606 | ||
607 | /** | |
608 | * spi_finalize_current_transfer - report completion of a transfer | |
609 | * | |
610 | * Called by SPI drivers using the core transfer_one_message() | |
611 | * implementation to notify it that the current interrupt driven | |
612 | * transfer has finised and the next one may be scheduled. | |
613 | */ | |
614 | void spi_finalize_current_transfer(struct spi_master *master) | |
615 | { | |
616 | complete(&master->xfer_completion); | |
617 | } | |
618 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
619 | ||
ffbbdd21 LW |
620 | /** |
621 | * spi_pump_messages - kthread work function which processes spi message queue | |
622 | * @work: pointer to kthread work struct contained in the master struct | |
623 | * | |
624 | * This function checks if there is any spi message in the queue that | |
625 | * needs processing and if so call out to the driver to initialize hardware | |
626 | * and transfer each message. | |
627 | * | |
628 | */ | |
629 | static void spi_pump_messages(struct kthread_work *work) | |
630 | { | |
631 | struct spi_master *master = | |
632 | container_of(work, struct spi_master, pump_messages); | |
633 | unsigned long flags; | |
634 | bool was_busy = false; | |
635 | int ret; | |
636 | ||
637 | /* Lock queue and check for queue work */ | |
638 | spin_lock_irqsave(&master->queue_lock, flags); | |
639 | if (list_empty(&master->queue) || !master->running) { | |
b0b36b86 BF |
640 | if (!master->busy) { |
641 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
642 | return; | |
ffbbdd21 LW |
643 | } |
644 | master->busy = false; | |
645 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
b0b36b86 BF |
646 | if (master->unprepare_transfer_hardware && |
647 | master->unprepare_transfer_hardware(master)) | |
648 | dev_err(&master->dev, | |
649 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
650 | if (master->auto_runtime_pm) { |
651 | pm_runtime_mark_last_busy(master->dev.parent); | |
652 | pm_runtime_put_autosuspend(master->dev.parent); | |
653 | } | |
56ec1978 | 654 | trace_spi_master_idle(master); |
ffbbdd21 LW |
655 | return; |
656 | } | |
657 | ||
658 | /* Make sure we are not already running a message */ | |
659 | if (master->cur_msg) { | |
660 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
661 | return; | |
662 | } | |
663 | /* Extract head of queue */ | |
664 | master->cur_msg = | |
665 | list_entry(master->queue.next, struct spi_message, queue); | |
666 | ||
667 | list_del_init(&master->cur_msg->queue); | |
668 | if (master->busy) | |
669 | was_busy = true; | |
670 | else | |
671 | master->busy = true; | |
672 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
673 | ||
49834de2 MB |
674 | if (!was_busy && master->auto_runtime_pm) { |
675 | ret = pm_runtime_get_sync(master->dev.parent); | |
676 | if (ret < 0) { | |
677 | dev_err(&master->dev, "Failed to power device: %d\n", | |
678 | ret); | |
679 | return; | |
680 | } | |
681 | } | |
682 | ||
56ec1978 MB |
683 | if (!was_busy) |
684 | trace_spi_master_busy(master); | |
685 | ||
7dfd2bd7 | 686 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
687 | ret = master->prepare_transfer_hardware(master); |
688 | if (ret) { | |
689 | dev_err(&master->dev, | |
690 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
691 | |
692 | if (master->auto_runtime_pm) | |
693 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
694 | return; |
695 | } | |
696 | } | |
697 | ||
56ec1978 MB |
698 | trace_spi_message_start(master->cur_msg); |
699 | ||
2841a5fc MB |
700 | if (master->prepare_message) { |
701 | ret = master->prepare_message(master, master->cur_msg); | |
702 | if (ret) { | |
703 | dev_err(&master->dev, | |
704 | "failed to prepare message: %d\n", ret); | |
705 | master->cur_msg->status = ret; | |
706 | spi_finalize_current_message(master); | |
707 | return; | |
708 | } | |
709 | master->cur_msg_prepared = true; | |
710 | } | |
711 | ||
ffbbdd21 LW |
712 | ret = master->transfer_one_message(master, master->cur_msg); |
713 | if (ret) { | |
714 | dev_err(&master->dev, | |
715 | "failed to transfer one message from queue\n"); | |
716 | return; | |
717 | } | |
718 | } | |
719 | ||
720 | static int spi_init_queue(struct spi_master *master) | |
721 | { | |
722 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
723 | ||
724 | INIT_LIST_HEAD(&master->queue); | |
725 | spin_lock_init(&master->queue_lock); | |
726 | ||
727 | master->running = false; | |
728 | master->busy = false; | |
729 | ||
730 | init_kthread_worker(&master->kworker); | |
731 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 732 | &master->kworker, "%s", |
ffbbdd21 LW |
733 | dev_name(&master->dev)); |
734 | if (IS_ERR(master->kworker_task)) { | |
735 | dev_err(&master->dev, "failed to create message pump task\n"); | |
736 | return -ENOMEM; | |
737 | } | |
738 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
739 | ||
740 | /* | |
741 | * Master config will indicate if this controller should run the | |
742 | * message pump with high (realtime) priority to reduce the transfer | |
743 | * latency on the bus by minimising the delay between a transfer | |
744 | * request and the scheduling of the message pump thread. Without this | |
745 | * setting the message pump thread will remain at default priority. | |
746 | */ | |
747 | if (master->rt) { | |
748 | dev_info(&master->dev, | |
749 | "will run message pump with realtime priority\n"); | |
750 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
751 | } | |
752 | ||
753 | return 0; | |
754 | } | |
755 | ||
756 | /** | |
757 | * spi_get_next_queued_message() - called by driver to check for queued | |
758 | * messages | |
759 | * @master: the master to check for queued messages | |
760 | * | |
761 | * If there are more messages in the queue, the next message is returned from | |
762 | * this call. | |
763 | */ | |
764 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
765 | { | |
766 | struct spi_message *next; | |
767 | unsigned long flags; | |
768 | ||
769 | /* get a pointer to the next message, if any */ | |
770 | spin_lock_irqsave(&master->queue_lock, flags); | |
771 | if (list_empty(&master->queue)) | |
772 | next = NULL; | |
773 | else | |
774 | next = list_entry(master->queue.next, | |
775 | struct spi_message, queue); | |
776 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
777 | ||
778 | return next; | |
779 | } | |
780 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
781 | ||
782 | /** | |
783 | * spi_finalize_current_message() - the current message is complete | |
784 | * @master: the master to return the message to | |
785 | * | |
786 | * Called by the driver to notify the core that the message in the front of the | |
787 | * queue is complete and can be removed from the queue. | |
788 | */ | |
789 | void spi_finalize_current_message(struct spi_master *master) | |
790 | { | |
791 | struct spi_message *mesg; | |
792 | unsigned long flags; | |
2841a5fc | 793 | int ret; |
ffbbdd21 LW |
794 | |
795 | spin_lock_irqsave(&master->queue_lock, flags); | |
796 | mesg = master->cur_msg; | |
797 | master->cur_msg = NULL; | |
798 | ||
799 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
800 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
801 | ||
2841a5fc MB |
802 | if (master->cur_msg_prepared && master->unprepare_message) { |
803 | ret = master->unprepare_message(master, mesg); | |
804 | if (ret) { | |
805 | dev_err(&master->dev, | |
806 | "failed to unprepare message: %d\n", ret); | |
807 | } | |
808 | } | |
809 | master->cur_msg_prepared = false; | |
810 | ||
ffbbdd21 LW |
811 | mesg->state = NULL; |
812 | if (mesg->complete) | |
813 | mesg->complete(mesg->context); | |
56ec1978 MB |
814 | |
815 | trace_spi_message_done(mesg); | |
ffbbdd21 LW |
816 | } |
817 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
818 | ||
819 | static int spi_start_queue(struct spi_master *master) | |
820 | { | |
821 | unsigned long flags; | |
822 | ||
823 | spin_lock_irqsave(&master->queue_lock, flags); | |
824 | ||
825 | if (master->running || master->busy) { | |
826 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
827 | return -EBUSY; | |
828 | } | |
829 | ||
830 | master->running = true; | |
831 | master->cur_msg = NULL; | |
832 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
833 | ||
834 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
835 | ||
836 | return 0; | |
837 | } | |
838 | ||
839 | static int spi_stop_queue(struct spi_master *master) | |
840 | { | |
841 | unsigned long flags; | |
842 | unsigned limit = 500; | |
843 | int ret = 0; | |
844 | ||
845 | spin_lock_irqsave(&master->queue_lock, flags); | |
846 | ||
847 | /* | |
848 | * This is a bit lame, but is optimized for the common execution path. | |
849 | * A wait_queue on the master->busy could be used, but then the common | |
850 | * execution path (pump_messages) would be required to call wake_up or | |
851 | * friends on every SPI message. Do this instead. | |
852 | */ | |
853 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
854 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
855 | msleep(10); | |
856 | spin_lock_irqsave(&master->queue_lock, flags); | |
857 | } | |
858 | ||
859 | if (!list_empty(&master->queue) || master->busy) | |
860 | ret = -EBUSY; | |
861 | else | |
862 | master->running = false; | |
863 | ||
864 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
865 | ||
866 | if (ret) { | |
867 | dev_warn(&master->dev, | |
868 | "could not stop message queue\n"); | |
869 | return ret; | |
870 | } | |
871 | return ret; | |
872 | } | |
873 | ||
874 | static int spi_destroy_queue(struct spi_master *master) | |
875 | { | |
876 | int ret; | |
877 | ||
878 | ret = spi_stop_queue(master); | |
879 | ||
880 | /* | |
881 | * flush_kthread_worker will block until all work is done. | |
882 | * If the reason that stop_queue timed out is that the work will never | |
883 | * finish, then it does no good to call flush/stop thread, so | |
884 | * return anyway. | |
885 | */ | |
886 | if (ret) { | |
887 | dev_err(&master->dev, "problem destroying queue\n"); | |
888 | return ret; | |
889 | } | |
890 | ||
891 | flush_kthread_worker(&master->kworker); | |
892 | kthread_stop(master->kworker_task); | |
893 | ||
894 | return 0; | |
895 | } | |
896 | ||
897 | /** | |
898 | * spi_queued_transfer - transfer function for queued transfers | |
899 | * @spi: spi device which is requesting transfer | |
900 | * @msg: spi message which is to handled is queued to driver queue | |
901 | */ | |
902 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
903 | { | |
904 | struct spi_master *master = spi->master; | |
905 | unsigned long flags; | |
906 | ||
907 | spin_lock_irqsave(&master->queue_lock, flags); | |
908 | ||
909 | if (!master->running) { | |
910 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
911 | return -ESHUTDOWN; | |
912 | } | |
913 | msg->actual_length = 0; | |
914 | msg->status = -EINPROGRESS; | |
915 | ||
916 | list_add_tail(&msg->queue, &master->queue); | |
96b3eace | 917 | if (!master->busy) |
ffbbdd21 LW |
918 | queue_kthread_work(&master->kworker, &master->pump_messages); |
919 | ||
920 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
921 | return 0; | |
922 | } | |
923 | ||
924 | static int spi_master_initialize_queue(struct spi_master *master) | |
925 | { | |
926 | int ret; | |
927 | ||
928 | master->queued = true; | |
929 | master->transfer = spi_queued_transfer; | |
b158935f MB |
930 | if (!master->transfer_one_message) |
931 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
932 | |
933 | /* Initialize and start queue */ | |
934 | ret = spi_init_queue(master); | |
935 | if (ret) { | |
936 | dev_err(&master->dev, "problem initializing queue\n"); | |
937 | goto err_init_queue; | |
938 | } | |
939 | ret = spi_start_queue(master); | |
940 | if (ret) { | |
941 | dev_err(&master->dev, "problem starting queue\n"); | |
942 | goto err_start_queue; | |
943 | } | |
944 | ||
945 | return 0; | |
946 | ||
947 | err_start_queue: | |
948 | err_init_queue: | |
949 | spi_destroy_queue(master); | |
950 | return ret; | |
951 | } | |
952 | ||
953 | /*-------------------------------------------------------------------------*/ | |
954 | ||
7cb94361 | 955 | #if defined(CONFIG_OF) |
d57a4282 GL |
956 | /** |
957 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
958 | * @master: Pointer to spi_master device | |
959 | * | |
960 | * Registers an spi_device for each child node of master node which has a 'reg' | |
961 | * property. | |
962 | */ | |
963 | static void of_register_spi_devices(struct spi_master *master) | |
964 | { | |
965 | struct spi_device *spi; | |
966 | struct device_node *nc; | |
d57a4282 | 967 | int rc; |
89da4293 | 968 | u32 value; |
d57a4282 GL |
969 | |
970 | if (!master->dev.of_node) | |
971 | return; | |
972 | ||
f3b6159e | 973 | for_each_available_child_of_node(master->dev.of_node, nc) { |
d57a4282 GL |
974 | /* Alloc an spi_device */ |
975 | spi = spi_alloc_device(master); | |
976 | if (!spi) { | |
977 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
978 | nc->full_name); | |
979 | spi_dev_put(spi); | |
980 | continue; | |
981 | } | |
982 | ||
983 | /* Select device driver */ | |
984 | if (of_modalias_node(nc, spi->modalias, | |
985 | sizeof(spi->modalias)) < 0) { | |
986 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
987 | nc->full_name); | |
988 | spi_dev_put(spi); | |
989 | continue; | |
990 | } | |
991 | ||
992 | /* Device address */ | |
89da4293 TP |
993 | rc = of_property_read_u32(nc, "reg", &value); |
994 | if (rc) { | |
995 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
996 | nc->full_name, rc); | |
d57a4282 GL |
997 | spi_dev_put(spi); |
998 | continue; | |
999 | } | |
89da4293 | 1000 | spi->chip_select = value; |
d57a4282 GL |
1001 | |
1002 | /* Mode (clock phase/polarity/etc.) */ | |
1003 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1004 | spi->mode |= SPI_CPHA; | |
1005 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1006 | spi->mode |= SPI_CPOL; | |
1007 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1008 | spi->mode |= SPI_CS_HIGH; | |
c20151df LPC |
1009 | if (of_find_property(nc, "spi-3wire", NULL)) |
1010 | spi->mode |= SPI_3WIRE; | |
d57a4282 | 1011 | |
f477b7fb | 1012 | /* Device DUAL/QUAD mode */ |
89da4293 TP |
1013 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
1014 | switch (value) { | |
1015 | case 1: | |
a822e99c | 1016 | break; |
89da4293 | 1017 | case 2: |
a822e99c MB |
1018 | spi->mode |= SPI_TX_DUAL; |
1019 | break; | |
89da4293 | 1020 | case 4: |
a822e99c MB |
1021 | spi->mode |= SPI_TX_QUAD; |
1022 | break; | |
1023 | default: | |
1024 | dev_err(&master->dev, | |
a110f93d | 1025 | "spi-tx-bus-width %d not supported\n", |
89da4293 | 1026 | value); |
a822e99c MB |
1027 | spi_dev_put(spi); |
1028 | continue; | |
1029 | } | |
f477b7fb | 1030 | } |
1031 | ||
89da4293 TP |
1032 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
1033 | switch (value) { | |
1034 | case 1: | |
a822e99c | 1035 | break; |
89da4293 | 1036 | case 2: |
a822e99c MB |
1037 | spi->mode |= SPI_RX_DUAL; |
1038 | break; | |
89da4293 | 1039 | case 4: |
a822e99c MB |
1040 | spi->mode |= SPI_RX_QUAD; |
1041 | break; | |
1042 | default: | |
1043 | dev_err(&master->dev, | |
a110f93d | 1044 | "spi-rx-bus-width %d not supported\n", |
89da4293 | 1045 | value); |
a822e99c MB |
1046 | spi_dev_put(spi); |
1047 | continue; | |
1048 | } | |
f477b7fb | 1049 | } |
1050 | ||
d57a4282 | 1051 | /* Device speed */ |
89da4293 TP |
1052 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); |
1053 | if (rc) { | |
1054 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1055 | nc->full_name, rc); | |
d57a4282 GL |
1056 | spi_dev_put(spi); |
1057 | continue; | |
1058 | } | |
89da4293 | 1059 | spi->max_speed_hz = value; |
d57a4282 GL |
1060 | |
1061 | /* IRQ */ | |
1062 | spi->irq = irq_of_parse_and_map(nc, 0); | |
1063 | ||
1064 | /* Store a pointer to the node in the device structure */ | |
1065 | of_node_get(nc); | |
1066 | spi->dev.of_node = nc; | |
1067 | ||
1068 | /* Register the new device */ | |
70fac17c | 1069 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); |
d57a4282 GL |
1070 | rc = spi_add_device(spi); |
1071 | if (rc) { | |
1072 | dev_err(&master->dev, "spi_device register error %s\n", | |
1073 | nc->full_name); | |
1074 | spi_dev_put(spi); | |
1075 | } | |
1076 | ||
1077 | } | |
1078 | } | |
1079 | #else | |
1080 | static void of_register_spi_devices(struct spi_master *master) { } | |
1081 | #endif | |
1082 | ||
64bee4d2 MW |
1083 | #ifdef CONFIG_ACPI |
1084 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1085 | { | |
1086 | struct spi_device *spi = data; | |
1087 | ||
1088 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1089 | struct acpi_resource_spi_serialbus *sb; | |
1090 | ||
1091 | sb = &ares->data.spi_serial_bus; | |
1092 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1093 | spi->chip_select = sb->device_selection; | |
1094 | spi->max_speed_hz = sb->connection_speed; | |
1095 | ||
1096 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1097 | spi->mode |= SPI_CPHA; | |
1098 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1099 | spi->mode |= SPI_CPOL; | |
1100 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1101 | spi->mode |= SPI_CS_HIGH; | |
1102 | } | |
1103 | } else if (spi->irq < 0) { | |
1104 | struct resource r; | |
1105 | ||
1106 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1107 | spi->irq = r.start; | |
1108 | } | |
1109 | ||
1110 | /* Always tell the ACPI core to skip this resource */ | |
1111 | return 1; | |
1112 | } | |
1113 | ||
1114 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1115 | void *data, void **return_value) | |
1116 | { | |
1117 | struct spi_master *master = data; | |
1118 | struct list_head resource_list; | |
1119 | struct acpi_device *adev; | |
1120 | struct spi_device *spi; | |
1121 | int ret; | |
1122 | ||
1123 | if (acpi_bus_get_device(handle, &adev)) | |
1124 | return AE_OK; | |
1125 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1126 | return AE_OK; | |
1127 | ||
1128 | spi = spi_alloc_device(master); | |
1129 | if (!spi) { | |
1130 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1131 | dev_name(&adev->dev)); | |
1132 | return AE_NO_MEMORY; | |
1133 | } | |
1134 | ||
1135 | ACPI_HANDLE_SET(&spi->dev, handle); | |
1136 | spi->irq = -1; | |
1137 | ||
1138 | INIT_LIST_HEAD(&resource_list); | |
1139 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1140 | acpi_spi_add_resource, spi); | |
1141 | acpi_dev_free_resource_list(&resource_list); | |
1142 | ||
1143 | if (ret < 0 || !spi->max_speed_hz) { | |
1144 | spi_dev_put(spi); | |
1145 | return AE_OK; | |
1146 | } | |
1147 | ||
cf9eb39c | 1148 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 MW |
1149 | if (spi_add_device(spi)) { |
1150 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", | |
1151 | dev_name(&adev->dev)); | |
1152 | spi_dev_put(spi); | |
1153 | } | |
1154 | ||
1155 | return AE_OK; | |
1156 | } | |
1157 | ||
1158 | static void acpi_register_spi_devices(struct spi_master *master) | |
1159 | { | |
1160 | acpi_status status; | |
1161 | acpi_handle handle; | |
1162 | ||
29896178 | 1163 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1164 | if (!handle) |
1165 | return; | |
1166 | ||
1167 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1168 | acpi_spi_add_device, NULL, | |
1169 | master, NULL); | |
1170 | if (ACPI_FAILURE(status)) | |
1171 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1172 | } | |
1173 | #else | |
1174 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1175 | #endif /* CONFIG_ACPI */ | |
1176 | ||
49dce689 | 1177 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1178 | { |
1179 | struct spi_master *master; | |
1180 | ||
49dce689 | 1181 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1182 | kfree(master); |
1183 | } | |
1184 | ||
1185 | static struct class spi_master_class = { | |
1186 | .name = "spi_master", | |
1187 | .owner = THIS_MODULE, | |
49dce689 | 1188 | .dev_release = spi_master_release, |
8ae12a0d DB |
1189 | }; |
1190 | ||
1191 | ||
ffbbdd21 | 1192 | |
8ae12a0d DB |
1193 | /** |
1194 | * spi_alloc_master - allocate SPI master controller | |
1195 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1196 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1197 | * memory is in the driver_data field of the returned device, |
0c868461 | 1198 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1199 | * Context: can sleep |
8ae12a0d DB |
1200 | * |
1201 | * This call is used only by SPI master controller drivers, which are the | |
1202 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1203 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1204 | * |
1205 | * This must be called from context that can sleep. It returns the SPI | |
1206 | * master structure on success, else NULL. | |
1207 | * | |
1208 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1209 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1210 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1211 | * leak. | |
8ae12a0d | 1212 | */ |
e9d5a461 | 1213 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1214 | { |
1215 | struct spi_master *master; | |
1216 | ||
0c868461 DB |
1217 | if (!dev) |
1218 | return NULL; | |
1219 | ||
5fe5f05e | 1220 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1221 | if (!master) |
1222 | return NULL; | |
1223 | ||
49dce689 | 1224 | device_initialize(&master->dev); |
1e8a52e1 GL |
1225 | master->bus_num = -1; |
1226 | master->num_chipselect = 1; | |
49dce689 TJ |
1227 | master->dev.class = &spi_master_class; |
1228 | master->dev.parent = get_device(dev); | |
0c868461 | 1229 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1230 | |
1231 | return master; | |
1232 | } | |
1233 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1234 | ||
74317984 JCPV |
1235 | #ifdef CONFIG_OF |
1236 | static int of_spi_register_master(struct spi_master *master) | |
1237 | { | |
e80beb27 | 1238 | int nb, i, *cs; |
74317984 JCPV |
1239 | struct device_node *np = master->dev.of_node; |
1240 | ||
1241 | if (!np) | |
1242 | return 0; | |
1243 | ||
1244 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1245 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1246 | |
8ec5d84e AL |
1247 | /* Return error only for an incorrectly formed cs-gpios property */ |
1248 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1249 | return 0; |
8ec5d84e AL |
1250 | else if (nb < 0) |
1251 | return nb; | |
74317984 JCPV |
1252 | |
1253 | cs = devm_kzalloc(&master->dev, | |
1254 | sizeof(int) * master->num_chipselect, | |
1255 | GFP_KERNEL); | |
1256 | master->cs_gpios = cs; | |
1257 | ||
1258 | if (!master->cs_gpios) | |
1259 | return -ENOMEM; | |
1260 | ||
0da83bb1 | 1261 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1262 | cs[i] = -ENOENT; |
74317984 JCPV |
1263 | |
1264 | for (i = 0; i < nb; i++) | |
1265 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1266 | ||
1267 | return 0; | |
1268 | } | |
1269 | #else | |
1270 | static int of_spi_register_master(struct spi_master *master) | |
1271 | { | |
1272 | return 0; | |
1273 | } | |
1274 | #endif | |
1275 | ||
8ae12a0d DB |
1276 | /** |
1277 | * spi_register_master - register SPI master controller | |
1278 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1279 | * Context: can sleep |
8ae12a0d DB |
1280 | * |
1281 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1282 | * such as the platform bus. The final stage of probe() in that code | |
1283 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1284 | * | |
1285 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1286 | * and board-specific addressing for SPI devices combines those numbers | |
1287 | * with chip select numbers. Since SPI does not directly support dynamic | |
1288 | * device identification, boards need configuration tables telling which | |
1289 | * chip is at which address. | |
1290 | * | |
1291 | * This must be called from context that can sleep. It returns zero on | |
1292 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1293 | * After a successful return, the caller is responsible for calling |
1294 | * spi_unregister_master(). | |
8ae12a0d | 1295 | */ |
e9d5a461 | 1296 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1297 | { |
e44a45ae | 1298 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1299 | struct device *dev = master->dev.parent; |
2b9603a0 | 1300 | struct boardinfo *bi; |
8ae12a0d DB |
1301 | int status = -ENODEV; |
1302 | int dynamic = 0; | |
1303 | ||
0c868461 DB |
1304 | if (!dev) |
1305 | return -ENODEV; | |
1306 | ||
74317984 JCPV |
1307 | status = of_spi_register_master(master); |
1308 | if (status) | |
1309 | return status; | |
1310 | ||
082c8cb4 DB |
1311 | /* even if it's just one always-selected device, there must |
1312 | * be at least one chipselect | |
1313 | */ | |
1314 | if (master->num_chipselect == 0) | |
1315 | return -EINVAL; | |
1316 | ||
bb29785e GL |
1317 | if ((master->bus_num < 0) && master->dev.of_node) |
1318 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1319 | ||
8ae12a0d | 1320 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1321 | if (master->bus_num < 0) { |
082c8cb4 DB |
1322 | /* FIXME switch to an IDR based scheme, something like |
1323 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1324 | */ | |
8ae12a0d | 1325 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1326 | dynamic = 1; |
8ae12a0d DB |
1327 | } |
1328 | ||
cf32b71e ES |
1329 | spin_lock_init(&master->bus_lock_spinlock); |
1330 | mutex_init(&master->bus_lock_mutex); | |
1331 | master->bus_lock_flag = 0; | |
b158935f | 1332 | init_completion(&master->xfer_completion); |
cf32b71e | 1333 | |
8ae12a0d DB |
1334 | /* register the device, then userspace will see it. |
1335 | * registration fails if the bus ID is in use. | |
1336 | */ | |
35f74fca | 1337 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1338 | status = device_add(&master->dev); |
b885244e | 1339 | if (status < 0) |
8ae12a0d | 1340 | goto done; |
35f74fca | 1341 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1342 | dynamic ? " (dynamic)" : ""); |
1343 | ||
ffbbdd21 LW |
1344 | /* If we're using a queued driver, start the queue */ |
1345 | if (master->transfer) | |
1346 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1347 | else { | |
1348 | status = spi_master_initialize_queue(master); | |
1349 | if (status) { | |
e93b0724 | 1350 | device_del(&master->dev); |
ffbbdd21 LW |
1351 | goto done; |
1352 | } | |
1353 | } | |
1354 | ||
2b9603a0 FT |
1355 | mutex_lock(&board_lock); |
1356 | list_add_tail(&master->list, &spi_master_list); | |
1357 | list_for_each_entry(bi, &board_list, list) | |
1358 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1359 | mutex_unlock(&board_lock); | |
1360 | ||
64bee4d2 | 1361 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1362 | of_register_spi_devices(master); |
64bee4d2 | 1363 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1364 | done: |
1365 | return status; | |
1366 | } | |
1367 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1368 | ||
666d5b4c MB |
1369 | static void devm_spi_unregister(struct device *dev, void *res) |
1370 | { | |
1371 | spi_unregister_master(*(struct spi_master **)res); | |
1372 | } | |
1373 | ||
1374 | /** | |
1375 | * dev_spi_register_master - register managed SPI master controller | |
1376 | * @dev: device managing SPI master | |
1377 | * @master: initialized master, originally from spi_alloc_master() | |
1378 | * Context: can sleep | |
1379 | * | |
1380 | * Register a SPI device as with spi_register_master() which will | |
1381 | * automatically be unregister | |
1382 | */ | |
1383 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1384 | { | |
1385 | struct spi_master **ptr; | |
1386 | int ret; | |
1387 | ||
1388 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1389 | if (!ptr) | |
1390 | return -ENOMEM; | |
1391 | ||
1392 | ret = spi_register_master(master); | |
1393 | if (ret != 0) { | |
1394 | *ptr = master; | |
1395 | devres_add(dev, ptr); | |
1396 | } else { | |
1397 | devres_free(ptr); | |
1398 | } | |
1399 | ||
1400 | return ret; | |
1401 | } | |
1402 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1403 | ||
34860089 | 1404 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1405 | { |
34860089 | 1406 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1407 | return 0; |
1408 | } | |
1409 | ||
1410 | /** | |
1411 | * spi_unregister_master - unregister SPI master controller | |
1412 | * @master: the master being unregistered | |
33e34dc6 | 1413 | * Context: can sleep |
8ae12a0d DB |
1414 | * |
1415 | * This call is used only by SPI master controller drivers, which are the | |
1416 | * only ones directly touching chip registers. | |
1417 | * | |
1418 | * This must be called from context that can sleep. | |
1419 | */ | |
1420 | void spi_unregister_master(struct spi_master *master) | |
1421 | { | |
89fc9a1a JG |
1422 | int dummy; |
1423 | ||
ffbbdd21 LW |
1424 | if (master->queued) { |
1425 | if (spi_destroy_queue(master)) | |
1426 | dev_err(&master->dev, "queue remove failed\n"); | |
1427 | } | |
1428 | ||
2b9603a0 FT |
1429 | mutex_lock(&board_lock); |
1430 | list_del(&master->list); | |
1431 | mutex_unlock(&board_lock); | |
1432 | ||
97dbf37d | 1433 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1434 | device_unregister(&master->dev); |
8ae12a0d DB |
1435 | } |
1436 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1437 | ||
ffbbdd21 LW |
1438 | int spi_master_suspend(struct spi_master *master) |
1439 | { | |
1440 | int ret; | |
1441 | ||
1442 | /* Basically no-ops for non-queued masters */ | |
1443 | if (!master->queued) | |
1444 | return 0; | |
1445 | ||
1446 | ret = spi_stop_queue(master); | |
1447 | if (ret) | |
1448 | dev_err(&master->dev, "queue stop failed\n"); | |
1449 | ||
1450 | return ret; | |
1451 | } | |
1452 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1453 | ||
1454 | int spi_master_resume(struct spi_master *master) | |
1455 | { | |
1456 | int ret; | |
1457 | ||
1458 | if (!master->queued) | |
1459 | return 0; | |
1460 | ||
1461 | ret = spi_start_queue(master); | |
1462 | if (ret) | |
1463 | dev_err(&master->dev, "queue restart failed\n"); | |
1464 | ||
1465 | return ret; | |
1466 | } | |
1467 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1468 | ||
9f3b795a | 1469 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1470 | { |
1471 | struct spi_master *m; | |
9f3b795a | 1472 | const u16 *bus_num = data; |
5ed2c832 DY |
1473 | |
1474 | m = container_of(dev, struct spi_master, dev); | |
1475 | return m->bus_num == *bus_num; | |
1476 | } | |
1477 | ||
8ae12a0d DB |
1478 | /** |
1479 | * spi_busnum_to_master - look up master associated with bus_num | |
1480 | * @bus_num: the master's bus number | |
33e34dc6 | 1481 | * Context: can sleep |
8ae12a0d DB |
1482 | * |
1483 | * This call may be used with devices that are registered after | |
1484 | * arch init time. It returns a refcounted pointer to the relevant | |
1485 | * spi_master (which the caller must release), or NULL if there is | |
1486 | * no such master registered. | |
1487 | */ | |
1488 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1489 | { | |
49dce689 | 1490 | struct device *dev; |
1e9a51dc | 1491 | struct spi_master *master = NULL; |
5ed2c832 | 1492 | |
695794ae | 1493 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1494 | __spi_master_match); |
1495 | if (dev) | |
1496 | master = container_of(dev, struct spi_master, dev); | |
1497 | /* reference got in class_find_device */ | |
1e9a51dc | 1498 | return master; |
8ae12a0d DB |
1499 | } |
1500 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1501 | ||
1502 | ||
1503 | /*-------------------------------------------------------------------------*/ | |
1504 | ||
7d077197 DB |
1505 | /* Core methods for SPI master protocol drivers. Some of the |
1506 | * other core methods are currently defined as inline functions. | |
1507 | */ | |
1508 | ||
1509 | /** | |
1510 | * spi_setup - setup SPI mode and clock rate | |
1511 | * @spi: the device whose settings are being modified | |
1512 | * Context: can sleep, and no requests are queued to the device | |
1513 | * | |
1514 | * SPI protocol drivers may need to update the transfer mode if the | |
1515 | * device doesn't work with its default. They may likewise need | |
1516 | * to update clock rates or word sizes from initial values. This function | |
1517 | * changes those settings, and must be called from a context that can sleep. | |
1518 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
1519 | * effect the next time the device is selected and data is transferred to | |
1520 | * or from it. When this function returns, the spi device is deselected. | |
1521 | * | |
1522 | * Note that this call will fail if the protocol driver specifies an option | |
1523 | * that the underlying controller or its driver does not support. For | |
1524 | * example, not all hardware supports wire transfers using nine bit words, | |
1525 | * LSB-first wire encoding, or active-high chipselects. | |
1526 | */ | |
1527 | int spi_setup(struct spi_device *spi) | |
1528 | { | |
e7db06b5 | 1529 | unsigned bad_bits; |
caae070c | 1530 | int status = 0; |
7d077197 | 1531 | |
f477b7fb | 1532 | /* check mode to prevent that DUAL and QUAD set at the same time |
1533 | */ | |
1534 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
1535 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
1536 | dev_err(&spi->dev, | |
1537 | "setup: can not select dual and quad at the same time\n"); | |
1538 | return -EINVAL; | |
1539 | } | |
1540 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
1541 | */ | |
1542 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
1543 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
1544 | return -EINVAL; | |
e7db06b5 DB |
1545 | /* help drivers fail *cleanly* when they need options |
1546 | * that aren't supported with their current master | |
1547 | */ | |
1548 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
1549 | if (bad_bits) { | |
eb288a1f | 1550 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1551 | bad_bits); |
1552 | return -EINVAL; | |
1553 | } | |
1554 | ||
7d077197 DB |
1555 | if (!spi->bits_per_word) |
1556 | spi->bits_per_word = 8; | |
1557 | ||
caae070c LD |
1558 | if (spi->master->setup) |
1559 | status = spi->master->setup(spi); | |
7d077197 | 1560 | |
5fe5f05e | 1561 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1562 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
1563 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
1564 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
1565 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
1566 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
1567 | spi->bits_per_word, spi->max_speed_hz, | |
1568 | status); | |
1569 | ||
1570 | return status; | |
1571 | } | |
1572 | EXPORT_SYMBOL_GPL(spi_setup); | |
1573 | ||
cf32b71e ES |
1574 | static int __spi_async(struct spi_device *spi, struct spi_message *message) |
1575 | { | |
1576 | struct spi_master *master = spi->master; | |
e6811d1d | 1577 | struct spi_transfer *xfer; |
cf32b71e | 1578 | |
56ec1978 MB |
1579 | message->spi = spi; |
1580 | ||
1581 | trace_spi_message_submit(message); | |
1582 | ||
24a0013a MB |
1583 | if (list_empty(&message->transfers)) |
1584 | return -EINVAL; | |
1585 | if (!message->complete) | |
1586 | return -EINVAL; | |
1587 | ||
cf32b71e ES |
1588 | /* Half-duplex links include original MicroWire, and ones with |
1589 | * only one data pin like SPI_3WIRE (switches direction) or where | |
1590 | * either MOSI or MISO is missing. They can also be caused by | |
1591 | * software limitations. | |
1592 | */ | |
1593 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
1594 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
1595 | unsigned flags = master->flags; |
1596 | ||
1597 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
1598 | if (xfer->rx_buf && xfer->tx_buf) | |
1599 | return -EINVAL; | |
1600 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
1601 | return -EINVAL; | |
1602 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
1603 | return -EINVAL; | |
1604 | } | |
1605 | } | |
1606 | ||
e6811d1d | 1607 | /** |
059b8ffe LD |
1608 | * Set transfer bits_per_word and max speed as spi device default if |
1609 | * it is not set for this transfer. | |
f477b7fb | 1610 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1611 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1612 | */ |
1613 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1614 | message->frame_length += xfer->len; |
e6811d1d LD |
1615 | if (!xfer->bits_per_word) |
1616 | xfer->bits_per_word = spi->bits_per_word; | |
56ede94a | 1617 | if (!xfer->speed_hz) { |
059b8ffe | 1618 | xfer->speed_hz = spi->max_speed_hz; |
56ede94a GJ |
1619 | if (master->max_speed_hz && |
1620 | xfer->speed_hz > master->max_speed_hz) | |
1621 | xfer->speed_hz = master->max_speed_hz; | |
1622 | } | |
1623 | ||
543bb255 SW |
1624 | if (master->bits_per_word_mask) { |
1625 | /* Only 32 bits fit in the mask */ | |
1626 | if (xfer->bits_per_word > 32) | |
1627 | return -EINVAL; | |
1628 | if (!(master->bits_per_word_mask & | |
1629 | BIT(xfer->bits_per_word - 1))) | |
1630 | return -EINVAL; | |
1631 | } | |
a2fd4f9f MB |
1632 | |
1633 | if (xfer->speed_hz && master->min_speed_hz && | |
1634 | xfer->speed_hz < master->min_speed_hz) | |
1635 | return -EINVAL; | |
1636 | if (xfer->speed_hz && master->max_speed_hz && | |
1637 | xfer->speed_hz > master->max_speed_hz) | |
d5ee722a | 1638 | return -EINVAL; |
f477b7fb | 1639 | |
1640 | if (xfer->tx_buf && !xfer->tx_nbits) | |
1641 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
1642 | if (xfer->rx_buf && !xfer->rx_nbits) | |
1643 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
1644 | /* check transfer tx/rx_nbits: | |
1645 | * 1. keep the value is not out of single, dual and quad | |
1646 | * 2. keep tx/rx_nbits is contained by mode in spi_device | |
1647 | * 3. if SPI_3WIRE, tx/rx_nbits should be in single | |
1648 | */ | |
db90a441 SP |
1649 | if (xfer->tx_buf) { |
1650 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
1651 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
1652 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
1653 | return -EINVAL; | |
1654 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
1655 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
1656 | return -EINVAL; | |
1657 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
1658 | !(spi->mode & SPI_TX_QUAD)) | |
1659 | return -EINVAL; | |
1660 | if ((spi->mode & SPI_3WIRE) && | |
1661 | (xfer->tx_nbits != SPI_NBITS_SINGLE)) | |
1662 | return -EINVAL; | |
1663 | } | |
f477b7fb | 1664 | /* check transfer rx_nbits */ |
db90a441 SP |
1665 | if (xfer->rx_buf) { |
1666 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
1667 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
1668 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
1669 | return -EINVAL; | |
1670 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
1671 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
1672 | return -EINVAL; | |
1673 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
1674 | !(spi->mode & SPI_RX_QUAD)) | |
1675 | return -EINVAL; | |
1676 | if ((spi->mode & SPI_3WIRE) && | |
1677 | (xfer->rx_nbits != SPI_NBITS_SINGLE)) | |
1678 | return -EINVAL; | |
1679 | } | |
e6811d1d LD |
1680 | } |
1681 | ||
cf32b71e ES |
1682 | message->status = -EINPROGRESS; |
1683 | return master->transfer(spi, message); | |
1684 | } | |
1685 | ||
568d0697 DB |
1686 | /** |
1687 | * spi_async - asynchronous SPI transfer | |
1688 | * @spi: device with which data will be exchanged | |
1689 | * @message: describes the data transfers, including completion callback | |
1690 | * Context: any (irqs may be blocked, etc) | |
1691 | * | |
1692 | * This call may be used in_irq and other contexts which can't sleep, | |
1693 | * as well as from task contexts which can sleep. | |
1694 | * | |
1695 | * The completion callback is invoked in a context which can't sleep. | |
1696 | * Before that invocation, the value of message->status is undefined. | |
1697 | * When the callback is issued, message->status holds either zero (to | |
1698 | * indicate complete success) or a negative error code. After that | |
1699 | * callback returns, the driver which issued the transfer request may | |
1700 | * deallocate the associated memory; it's no longer in use by any SPI | |
1701 | * core or controller driver code. | |
1702 | * | |
1703 | * Note that although all messages to a spi_device are handled in | |
1704 | * FIFO order, messages may go to different devices in other orders. | |
1705 | * Some device might be higher priority, or have various "hard" access | |
1706 | * time requirements, for example. | |
1707 | * | |
1708 | * On detection of any fault during the transfer, processing of | |
1709 | * the entire message is aborted, and the device is deselected. | |
1710 | * Until returning from the associated message completion callback, | |
1711 | * no other spi_message queued to that device will be processed. | |
1712 | * (This rule applies equally to all the synchronous transfer calls, | |
1713 | * which are wrappers around this core asynchronous primitive.) | |
1714 | */ | |
1715 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
1716 | { | |
1717 | struct spi_master *master = spi->master; | |
cf32b71e ES |
1718 | int ret; |
1719 | unsigned long flags; | |
568d0697 | 1720 | |
cf32b71e | 1721 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 1722 | |
cf32b71e ES |
1723 | if (master->bus_lock_flag) |
1724 | ret = -EBUSY; | |
1725 | else | |
1726 | ret = __spi_async(spi, message); | |
568d0697 | 1727 | |
cf32b71e ES |
1728 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
1729 | ||
1730 | return ret; | |
568d0697 DB |
1731 | } |
1732 | EXPORT_SYMBOL_GPL(spi_async); | |
1733 | ||
cf32b71e ES |
1734 | /** |
1735 | * spi_async_locked - version of spi_async with exclusive bus usage | |
1736 | * @spi: device with which data will be exchanged | |
1737 | * @message: describes the data transfers, including completion callback | |
1738 | * Context: any (irqs may be blocked, etc) | |
1739 | * | |
1740 | * This call may be used in_irq and other contexts which can't sleep, | |
1741 | * as well as from task contexts which can sleep. | |
1742 | * | |
1743 | * The completion callback is invoked in a context which can't sleep. | |
1744 | * Before that invocation, the value of message->status is undefined. | |
1745 | * When the callback is issued, message->status holds either zero (to | |
1746 | * indicate complete success) or a negative error code. After that | |
1747 | * callback returns, the driver which issued the transfer request may | |
1748 | * deallocate the associated memory; it's no longer in use by any SPI | |
1749 | * core or controller driver code. | |
1750 | * | |
1751 | * Note that although all messages to a spi_device are handled in | |
1752 | * FIFO order, messages may go to different devices in other orders. | |
1753 | * Some device might be higher priority, or have various "hard" access | |
1754 | * time requirements, for example. | |
1755 | * | |
1756 | * On detection of any fault during the transfer, processing of | |
1757 | * the entire message is aborted, and the device is deselected. | |
1758 | * Until returning from the associated message completion callback, | |
1759 | * no other spi_message queued to that device will be processed. | |
1760 | * (This rule applies equally to all the synchronous transfer calls, | |
1761 | * which are wrappers around this core asynchronous primitive.) | |
1762 | */ | |
1763 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
1764 | { | |
1765 | struct spi_master *master = spi->master; | |
1766 | int ret; | |
1767 | unsigned long flags; | |
1768 | ||
1769 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
1770 | ||
1771 | ret = __spi_async(spi, message); | |
1772 | ||
1773 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
1774 | ||
1775 | return ret; | |
1776 | ||
1777 | } | |
1778 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
1779 | ||
7d077197 DB |
1780 | |
1781 | /*-------------------------------------------------------------------------*/ | |
1782 | ||
1783 | /* Utility methods for SPI master protocol drivers, layered on | |
1784 | * top of the core. Some other utility methods are defined as | |
1785 | * inline functions. | |
1786 | */ | |
1787 | ||
5d870c8e AM |
1788 | static void spi_complete(void *arg) |
1789 | { | |
1790 | complete(arg); | |
1791 | } | |
1792 | ||
cf32b71e ES |
1793 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
1794 | int bus_locked) | |
1795 | { | |
1796 | DECLARE_COMPLETION_ONSTACK(done); | |
1797 | int status; | |
1798 | struct spi_master *master = spi->master; | |
1799 | ||
1800 | message->complete = spi_complete; | |
1801 | message->context = &done; | |
1802 | ||
1803 | if (!bus_locked) | |
1804 | mutex_lock(&master->bus_lock_mutex); | |
1805 | ||
1806 | status = spi_async_locked(spi, message); | |
1807 | ||
1808 | if (!bus_locked) | |
1809 | mutex_unlock(&master->bus_lock_mutex); | |
1810 | ||
1811 | if (status == 0) { | |
1812 | wait_for_completion(&done); | |
1813 | status = message->status; | |
1814 | } | |
1815 | message->context = NULL; | |
1816 | return status; | |
1817 | } | |
1818 | ||
8ae12a0d DB |
1819 | /** |
1820 | * spi_sync - blocking/synchronous SPI data transfers | |
1821 | * @spi: device with which data will be exchanged | |
1822 | * @message: describes the data transfers | |
33e34dc6 | 1823 | * Context: can sleep |
8ae12a0d DB |
1824 | * |
1825 | * This call may only be used from a context that may sleep. The sleep | |
1826 | * is non-interruptible, and has no timeout. Low-overhead controller | |
1827 | * drivers may DMA directly into and out of the message buffers. | |
1828 | * | |
1829 | * Note that the SPI device's chip select is active during the message, | |
1830 | * and then is normally disabled between messages. Drivers for some | |
1831 | * frequently-used devices may want to minimize costs of selecting a chip, | |
1832 | * by leaving it selected in anticipation that the next message will go | |
1833 | * to the same chip. (That may increase power usage.) | |
1834 | * | |
0c868461 DB |
1835 | * Also, the caller is guaranteeing that the memory associated with the |
1836 | * message will not be freed before this call returns. | |
1837 | * | |
9b938b74 | 1838 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
1839 | */ |
1840 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
1841 | { | |
cf32b71e | 1842 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
1843 | } |
1844 | EXPORT_SYMBOL_GPL(spi_sync); | |
1845 | ||
cf32b71e ES |
1846 | /** |
1847 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
1848 | * @spi: device with which data will be exchanged | |
1849 | * @message: describes the data transfers | |
1850 | * Context: can sleep | |
1851 | * | |
1852 | * This call may only be used from a context that may sleep. The sleep | |
1853 | * is non-interruptible, and has no timeout. Low-overhead controller | |
1854 | * drivers may DMA directly into and out of the message buffers. | |
1855 | * | |
1856 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 1857 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
1858 | * be released by a spi_bus_unlock call when the exclusive access is over. |
1859 | * | |
1860 | * It returns zero on success, else a negative error code. | |
1861 | */ | |
1862 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
1863 | { | |
1864 | return __spi_sync(spi, message, 1); | |
1865 | } | |
1866 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
1867 | ||
1868 | /** | |
1869 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
1870 | * @master: SPI bus master that should be locked for exclusive bus access | |
1871 | * Context: can sleep | |
1872 | * | |
1873 | * This call may only be used from a context that may sleep. The sleep | |
1874 | * is non-interruptible, and has no timeout. | |
1875 | * | |
1876 | * This call should be used by drivers that require exclusive access to the | |
1877 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
1878 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
1879 | * and spi_async_locked calls when the SPI bus lock is held. | |
1880 | * | |
1881 | * It returns zero on success, else a negative error code. | |
1882 | */ | |
1883 | int spi_bus_lock(struct spi_master *master) | |
1884 | { | |
1885 | unsigned long flags; | |
1886 | ||
1887 | mutex_lock(&master->bus_lock_mutex); | |
1888 | ||
1889 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
1890 | master->bus_lock_flag = 1; | |
1891 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
1892 | ||
1893 | /* mutex remains locked until spi_bus_unlock is called */ | |
1894 | ||
1895 | return 0; | |
1896 | } | |
1897 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
1898 | ||
1899 | /** | |
1900 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
1901 | * @master: SPI bus master that was locked for exclusive bus access | |
1902 | * Context: can sleep | |
1903 | * | |
1904 | * This call may only be used from a context that may sleep. The sleep | |
1905 | * is non-interruptible, and has no timeout. | |
1906 | * | |
1907 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
1908 | * call. | |
1909 | * | |
1910 | * It returns zero on success, else a negative error code. | |
1911 | */ | |
1912 | int spi_bus_unlock(struct spi_master *master) | |
1913 | { | |
1914 | master->bus_lock_flag = 0; | |
1915 | ||
1916 | mutex_unlock(&master->bus_lock_mutex); | |
1917 | ||
1918 | return 0; | |
1919 | } | |
1920 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
1921 | ||
a9948b61 | 1922 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 1923 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
1924 | |
1925 | static u8 *buf; | |
1926 | ||
1927 | /** | |
1928 | * spi_write_then_read - SPI synchronous write followed by read | |
1929 | * @spi: device with which data will be exchanged | |
1930 | * @txbuf: data to be written (need not be dma-safe) | |
1931 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
1932 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
1933 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 1934 | * Context: can sleep |
8ae12a0d DB |
1935 | * |
1936 | * This performs a half duplex MicroWire style transaction with the | |
1937 | * device, sending txbuf and then reading rxbuf. The return value | |
1938 | * is zero for success, else a negative errno status code. | |
b885244e | 1939 | * This call may only be used from a context that may sleep. |
8ae12a0d | 1940 | * |
0c868461 | 1941 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
1942 | * portable code should never use this for more than 32 bytes. |
1943 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 1944 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
1945 | */ |
1946 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
1947 | const void *txbuf, unsigned n_tx, |
1948 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 1949 | { |
068f4070 | 1950 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
1951 | |
1952 | int status; | |
1953 | struct spi_message message; | |
bdff549e | 1954 | struct spi_transfer x[2]; |
8ae12a0d DB |
1955 | u8 *local_buf; |
1956 | ||
b3a223ee MB |
1957 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
1958 | * copying here, (as a pure convenience thing), but we can | |
1959 | * keep heap costs out of the hot path unless someone else is | |
1960 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 1961 | */ |
b3a223ee | 1962 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
1963 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
1964 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
1965 | if (!local_buf) |
1966 | return -ENOMEM; | |
1967 | } else { | |
1968 | local_buf = buf; | |
1969 | } | |
8ae12a0d | 1970 | |
8275c642 | 1971 | spi_message_init(&message); |
5fe5f05e | 1972 | memset(x, 0, sizeof(x)); |
bdff549e DB |
1973 | if (n_tx) { |
1974 | x[0].len = n_tx; | |
1975 | spi_message_add_tail(&x[0], &message); | |
1976 | } | |
1977 | if (n_rx) { | |
1978 | x[1].len = n_rx; | |
1979 | spi_message_add_tail(&x[1], &message); | |
1980 | } | |
8275c642 | 1981 | |
8ae12a0d | 1982 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
1983 | x[0].tx_buf = local_buf; |
1984 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
1985 | |
1986 | /* do the i/o */ | |
8ae12a0d | 1987 | status = spi_sync(spi, &message); |
9b938b74 | 1988 | if (status == 0) |
bdff549e | 1989 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 1990 | |
bdff549e | 1991 | if (x[0].tx_buf == buf) |
068f4070 | 1992 | mutex_unlock(&lock); |
8ae12a0d DB |
1993 | else |
1994 | kfree(local_buf); | |
1995 | ||
1996 | return status; | |
1997 | } | |
1998 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
1999 | ||
2000 | /*-------------------------------------------------------------------------*/ | |
2001 | ||
2002 | static int __init spi_init(void) | |
2003 | { | |
b885244e DB |
2004 | int status; |
2005 | ||
e94b1766 | 2006 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2007 | if (!buf) { |
2008 | status = -ENOMEM; | |
2009 | goto err0; | |
2010 | } | |
2011 | ||
2012 | status = bus_register(&spi_bus_type); | |
2013 | if (status < 0) | |
2014 | goto err1; | |
8ae12a0d | 2015 | |
b885244e DB |
2016 | status = class_register(&spi_master_class); |
2017 | if (status < 0) | |
2018 | goto err2; | |
8ae12a0d | 2019 | return 0; |
b885244e DB |
2020 | |
2021 | err2: | |
2022 | bus_unregister(&spi_bus_type); | |
2023 | err1: | |
2024 | kfree(buf); | |
2025 | buf = NULL; | |
2026 | err0: | |
2027 | return status; | |
8ae12a0d | 2028 | } |
b885244e | 2029 | |
8ae12a0d DB |
2030 | /* board_info is normally registered in arch_initcall(), |
2031 | * but even essential drivers wait till later | |
b885244e DB |
2032 | * |
2033 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2034 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2035 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2036 | */ |
673c0c00 | 2037 | postcore_initcall(spi_init); |
8ae12a0d | 2038 |