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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); | |
33cf00e5 MW |
248 | struct spi_device *spi = to_spi_device(dev); |
249 | int ret; | |
250 | ||
251 | acpi_dev_pm_attach(&spi->dev, true); | |
252 | ret = sdrv->probe(spi); | |
253 | if (ret) | |
254 | acpi_dev_pm_detach(&spi->dev, true); | |
b885244e | 255 | |
33cf00e5 | 256 | return ret; |
b885244e DB |
257 | } |
258 | ||
259 | static int spi_drv_remove(struct device *dev) | |
260 | { | |
261 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
262 | struct spi_device *spi = to_spi_device(dev); |
263 | int ret; | |
264 | ||
265 | ret = sdrv->remove(spi); | |
266 | acpi_dev_pm_detach(&spi->dev, true); | |
b885244e | 267 | |
33cf00e5 | 268 | return ret; |
b885244e DB |
269 | } |
270 | ||
271 | static 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 | ||
33e34dc6 DB |
278 | /** |
279 | * spi_register_driver - register a SPI driver | |
280 | * @sdrv: the driver to register | |
281 | * Context: can sleep | |
282 | */ | |
b885244e DB |
283 | int 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 | } | |
294 | EXPORT_SYMBOL_GPL(spi_register_driver); | |
295 | ||
8ae12a0d DB |
296 | /*-------------------------------------------------------------------------*/ |
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 | ||
304 | struct boardinfo { | |
305 | struct list_head list; | |
2b9603a0 | 306 | struct spi_board_info board_info; |
8ae12a0d DB |
307 | }; |
308 | ||
309 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
310 | static 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 | */ | |
94040828 | 316 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 317 | |
dc87c98e GL |
318 | /** |
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 | */ | |
335 | struct 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 | ||
5fe5f05e | 343 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e GL |
344 | 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; | |
178db7d3 | 351 | spi->dev.parent = &master->dev; |
dc87c98e GL |
352 | spi->dev.bus = &spi_bus_type; |
353 | spi->dev.release = spidev_release; | |
446411e1 | 354 | spi->cs_gpio = -ENOENT; |
dc87c98e GL |
355 | device_initialize(&spi->dev); |
356 | return spi; | |
357 | } | |
358 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
359 | ||
e13ac47b JN |
360 | static 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 | ||
dc87c98e GL |
373 | /** |
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 | * | |
e48880e0 | 380 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
381 | */ |
382 | int spi_add_device(struct spi_device *spi) | |
383 | { | |
e48880e0 | 384 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
385 | struct spi_master *master = spi->master; |
386 | struct device *dev = master->dev.parent; | |
8ec130a0 | 387 | struct device *d; |
dc87c98e GL |
388 | int status; |
389 | ||
390 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 391 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
392 | dev_err(dev, "cs%d >= max %d\n", |
393 | spi->chip_select, | |
74317984 | 394 | master->num_chipselect); |
dc87c98e GL |
395 | return -EINVAL; |
396 | } | |
397 | ||
398 | /* Set the bus ID string */ | |
e13ac47b | 399 | spi_dev_set_name(spi); |
e48880e0 DB |
400 | |
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 | ||
8ec130a0 RT |
407 | d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)); |
408 | if (d != NULL) { | |
e48880e0 DB |
409 | dev_err(dev, "chipselect %d already in use\n", |
410 | spi->chip_select); | |
8ec130a0 | 411 | put_device(d); |
e48880e0 DB |
412 | status = -EBUSY; |
413 | goto done; | |
414 | } | |
415 | ||
74317984 JCPV |
416 | if (master->cs_gpios) |
417 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
418 | ||
e48880e0 DB |
419 | /* 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 | */ | |
7d077197 | 423 | status = spi_setup(spi); |
dc87c98e | 424 | if (status < 0) { |
eb288a1f LW |
425 | dev_err(dev, "can't setup %s, status %d\n", |
426 | dev_name(&spi->dev), status); | |
e48880e0 | 427 | goto done; |
dc87c98e GL |
428 | } |
429 | ||
e48880e0 | 430 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 431 | status = device_add(&spi->dev); |
e48880e0 | 432 | if (status < 0) |
eb288a1f LW |
433 | dev_err(dev, "can't add %s, status %d\n", |
434 | dev_name(&spi->dev), status); | |
e48880e0 | 435 | else |
35f74fca | 436 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 437 | |
e48880e0 DB |
438 | done: |
439 | mutex_unlock(&spi_add_lock); | |
440 | return status; | |
dc87c98e GL |
441 | } |
442 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 443 | |
33e34dc6 DB |
444 | /** |
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 | |
8ae12a0d DB |
451 | * 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). | |
082c8cb4 DB |
455 | * |
456 | * Returns the new device, or NULL. | |
8ae12a0d | 457 | */ |
e9d5a461 AB |
458 | struct spi_device *spi_new_device(struct spi_master *master, |
459 | struct spi_board_info *chip) | |
8ae12a0d DB |
460 | { |
461 | struct spi_device *proxy; | |
8ae12a0d DB |
462 | int status; |
463 | ||
082c8cb4 DB |
464 | /* 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 | ||
dc87c98e GL |
471 | proxy = spi_alloc_device(master); |
472 | if (!proxy) | |
8ae12a0d DB |
473 | return NULL; |
474 | ||
102eb975 GL |
475 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
476 | ||
8ae12a0d DB |
477 | proxy->chip_select = chip->chip_select; |
478 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 479 | proxy->mode = chip->mode; |
8ae12a0d | 480 | proxy->irq = chip->irq; |
102eb975 | 481 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
482 | proxy->dev.platform_data = (void *) chip->platform_data; |
483 | proxy->controller_data = chip->controller_data; | |
484 | proxy->controller_state = NULL; | |
8ae12a0d | 485 | |
dc87c98e | 486 | status = spi_add_device(proxy); |
8ae12a0d | 487 | if (status < 0) { |
dc87c98e GL |
488 | spi_dev_put(proxy); |
489 | return NULL; | |
8ae12a0d DB |
490 | } |
491 | ||
8ae12a0d DB |
492 | return proxy; |
493 | } | |
494 | EXPORT_SYMBOL_GPL(spi_new_device); | |
495 | ||
2b9603a0 FT |
496 | static 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 | ||
33e34dc6 DB |
510 | /** |
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 | * | |
8ae12a0d DB |
516 | * 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 | */ | |
fd4a319b | 529 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 530 | { |
2b9603a0 FT |
531 | struct boardinfo *bi; |
532 | int i; | |
8ae12a0d | 533 | |
2b9603a0 | 534 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
535 | if (!bi) |
536 | return -ENOMEM; | |
8ae12a0d | 537 | |
2b9603a0 FT |
538 | for (i = 0; i < n; i++, bi++, info++) { |
539 | struct spi_master *master; | |
8ae12a0d | 540 | |
2b9603a0 FT |
541 | 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); | |
8ae12a0d | 547 | } |
2b9603a0 FT |
548 | |
549 | return 0; | |
8ae12a0d DB |
550 | } |
551 | ||
552 | /*-------------------------------------------------------------------------*/ | |
553 | ||
b158935f MB |
554 | static 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 | */ | |
572 | static 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 | ||
16735d02 | 585 | reinit_completion(&master->xfer_completion); |
b158935f MB |
586 | |
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 | ||
618 | out: | |
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 | */ | |
637 | void spi_finalize_current_transfer(struct spi_master *master) | |
638 | { | |
639 | complete(&master->xfer_completion); | |
640 | } | |
641 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
642 | ||
ffbbdd21 LW |
643 | /** |
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 | */ | |
652 | static 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) { | |
b0b36b86 BF |
663 | if (!master->busy) { |
664 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
665 | return; | |
ffbbdd21 LW |
666 | } |
667 | master->busy = false; | |
668 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
b0b36b86 BF |
669 | if (master->unprepare_transfer_hardware && |
670 | master->unprepare_transfer_hardware(master)) | |
671 | dev_err(&master->dev, | |
672 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
673 | if (master->auto_runtime_pm) { |
674 | pm_runtime_mark_last_busy(master->dev.parent); | |
675 | pm_runtime_put_autosuspend(master->dev.parent); | |
676 | } | |
56ec1978 | 677 | trace_spi_master_idle(master); |
ffbbdd21 LW |
678 | 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 | ||
49834de2 MB |
697 | 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 | ||
56ec1978 MB |
706 | if (!was_busy) |
707 | trace_spi_master_busy(master); | |
708 | ||
7dfd2bd7 | 709 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
710 | ret = master->prepare_transfer_hardware(master); |
711 | if (ret) { | |
712 | dev_err(&master->dev, | |
713 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
714 | |
715 | if (master->auto_runtime_pm) | |
716 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
717 | return; |
718 | } | |
719 | } | |
720 | ||
56ec1978 MB |
721 | trace_spi_message_start(master->cur_msg); |
722 | ||
2841a5fc MB |
723 | 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 | ||
ffbbdd21 LW |
735 | 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 | ||
743 | static 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, | |
f170168b | 755 | &master->kworker, "%s", |
ffbbdd21 LW |
756 | 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, ¶m); | |
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 | */ | |
787 | struct 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 | } | |
803 | EXPORT_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 | */ | |
812 | void spi_finalize_current_message(struct spi_master *master) | |
813 | { | |
814 | struct spi_message *mesg; | |
815 | unsigned long flags; | |
2841a5fc | 816 | int ret; |
ffbbdd21 LW |
817 | |
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 | ||
2841a5fc MB |
825 | 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 | ||
ffbbdd21 LW |
834 | mesg->state = NULL; |
835 | if (mesg->complete) | |
836 | mesg->complete(mesg->context); | |
56ec1978 MB |
837 | |
838 | trace_spi_message_done(mesg); | |
ffbbdd21 LW |
839 | } |
840 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
841 | ||
842 | static 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 | ||
862 | static 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 | ||
897 | static 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 | */ | |
925 | static 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); | |
96b3eace | 940 | if (!master->busy) |
ffbbdd21 LW |
941 | queue_kthread_work(&master->kworker, &master->pump_messages); |
942 | ||
943 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
944 | return 0; | |
945 | } | |
946 | ||
947 | static int spi_master_initialize_queue(struct spi_master *master) | |
948 | { | |
949 | int ret; | |
950 | ||
951 | master->queued = true; | |
952 | master->transfer = spi_queued_transfer; | |
b158935f MB |
953 | if (!master->transfer_one_message) |
954 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
955 | |
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 | ||
970 | err_start_queue: | |
971 | err_init_queue: | |
972 | spi_destroy_queue(master); | |
973 | return ret; | |
974 | } | |
975 | ||
976 | /*-------------------------------------------------------------------------*/ | |
977 | ||
7cb94361 | 978 | #if defined(CONFIG_OF) |
d57a4282 GL |
979 | /** |
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 | */ | |
986 | static void of_register_spi_devices(struct spi_master *master) | |
987 | { | |
988 | struct spi_device *spi; | |
989 | struct device_node *nc; | |
d57a4282 | 990 | int rc; |
89da4293 | 991 | u32 value; |
d57a4282 GL |
992 | |
993 | if (!master->dev.of_node) | |
994 | return; | |
995 | ||
f3b6159e | 996 | for_each_available_child_of_node(master->dev.of_node, nc) { |
d57a4282 GL |
997 | /* 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 */ | |
89da4293 TP |
1016 | 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); | |
d57a4282 GL |
1020 | spi_dev_put(spi); |
1021 | continue; | |
1022 | } | |
89da4293 | 1023 | spi->chip_select = value; |
d57a4282 GL |
1024 | |
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; | |
c20151df LPC |
1032 | if (of_find_property(nc, "spi-3wire", NULL)) |
1033 | spi->mode |= SPI_3WIRE; | |
d57a4282 | 1034 | |
f477b7fb | 1035 | /* Device DUAL/QUAD mode */ |
89da4293 TP |
1036 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
1037 | switch (value) { | |
1038 | case 1: | |
a822e99c | 1039 | break; |
89da4293 | 1040 | case 2: |
a822e99c MB |
1041 | spi->mode |= SPI_TX_DUAL; |
1042 | break; | |
89da4293 | 1043 | case 4: |
a822e99c MB |
1044 | spi->mode |= SPI_TX_QUAD; |
1045 | break; | |
1046 | default: | |
1047 | dev_err(&master->dev, | |
a110f93d | 1048 | "spi-tx-bus-width %d not supported\n", |
89da4293 | 1049 | value); |
a822e99c MB |
1050 | spi_dev_put(spi); |
1051 | continue; | |
1052 | } | |
f477b7fb | 1053 | } |
1054 | ||
89da4293 TP |
1055 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
1056 | switch (value) { | |
1057 | case 1: | |
a822e99c | 1058 | break; |
89da4293 | 1059 | case 2: |
a822e99c MB |
1060 | spi->mode |= SPI_RX_DUAL; |
1061 | break; | |
89da4293 | 1062 | case 4: |
a822e99c MB |
1063 | spi->mode |= SPI_RX_QUAD; |
1064 | break; | |
1065 | default: | |
1066 | dev_err(&master->dev, | |
a110f93d | 1067 | "spi-rx-bus-width %d not supported\n", |
89da4293 | 1068 | value); |
a822e99c MB |
1069 | spi_dev_put(spi); |
1070 | continue; | |
1071 | } | |
f477b7fb | 1072 | } |
1073 | ||
d57a4282 | 1074 | /* Device speed */ |
89da4293 TP |
1075 | 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); | |
d57a4282 GL |
1079 | spi_dev_put(spi); |
1080 | continue; | |
1081 | } | |
89da4293 | 1082 | spi->max_speed_hz = value; |
d57a4282 GL |
1083 | |
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 */ | |
70fac17c | 1092 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); |
d57a4282 GL |
1093 | 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 | |
1103 | static void of_register_spi_devices(struct spi_master *master) { } | |
1104 | #endif | |
1105 | ||
64bee4d2 MW |
1106 | #ifdef CONFIG_ACPI |
1107 | static 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 | ||
1137 | static 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 | ||
7b199811 | 1158 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1159 | 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 | ||
33cf00e5 | 1171 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1172 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1173 | if (spi_add_device(spi)) { |
33cf00e5 | 1174 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1175 | 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 | ||
1183 | static void acpi_register_spi_devices(struct spi_master *master) | |
1184 | { | |
1185 | acpi_status status; | |
1186 | acpi_handle handle; | |
1187 | ||
29896178 | 1188 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1189 | 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 | |
1199 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1200 | #endif /* CONFIG_ACPI */ | |
1201 | ||
49dce689 | 1202 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1203 | { |
1204 | struct spi_master *master; | |
1205 | ||
49dce689 | 1206 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1207 | kfree(master); |
1208 | } | |
1209 | ||
1210 | static struct class spi_master_class = { | |
1211 | .name = "spi_master", | |
1212 | .owner = THIS_MODULE, | |
49dce689 | 1213 | .dev_release = spi_master_release, |
8ae12a0d DB |
1214 | }; |
1215 | ||
1216 | ||
ffbbdd21 | 1217 | |
8ae12a0d DB |
1218 | /** |
1219 | * spi_alloc_master - allocate SPI master controller | |
1220 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1221 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1222 | * memory is in the driver_data field of the returned device, |
0c868461 | 1223 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1224 | * Context: can sleep |
8ae12a0d DB |
1225 | * |
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 | |
ba1a0513 | 1228 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1229 | * |
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 | |
ba1a0513 | 1234 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1235 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1236 | * leak. | |
8ae12a0d | 1237 | */ |
e9d5a461 | 1238 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1239 | { |
1240 | struct spi_master *master; | |
1241 | ||
0c868461 DB |
1242 | if (!dev) |
1243 | return NULL; | |
1244 | ||
5fe5f05e | 1245 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1246 | if (!master) |
1247 | return NULL; | |
1248 | ||
49dce689 | 1249 | device_initialize(&master->dev); |
1e8a52e1 GL |
1250 | master->bus_num = -1; |
1251 | master->num_chipselect = 1; | |
49dce689 TJ |
1252 | master->dev.class = &spi_master_class; |
1253 | master->dev.parent = get_device(dev); | |
0c868461 | 1254 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1255 | |
1256 | return master; | |
1257 | } | |
1258 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1259 | ||
74317984 JCPV |
1260 | #ifdef CONFIG_OF |
1261 | static int of_spi_register_master(struct spi_master *master) | |
1262 | { | |
e80beb27 | 1263 | int nb, i, *cs; |
74317984 JCPV |
1264 | 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"); | |
5fe5f05e | 1270 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1271 | |
8ec5d84e AL |
1272 | /* Return error only for an incorrectly formed cs-gpios property */ |
1273 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1274 | return 0; |
8ec5d84e AL |
1275 | else if (nb < 0) |
1276 | return nb; | |
74317984 JCPV |
1277 | |
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 | ||
0da83bb1 | 1286 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1287 | cs[i] = -ENOENT; |
74317984 JCPV |
1288 | |
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 | |
1295 | static int of_spi_register_master(struct spi_master *master) | |
1296 | { | |
1297 | return 0; | |
1298 | } | |
1299 | #endif | |
1300 | ||
8ae12a0d DB |
1301 | /** |
1302 | * spi_register_master - register SPI master controller | |
1303 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1304 | * Context: can sleep |
8ae12a0d DB |
1305 | * |
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). | |
0c868461 DB |
1318 | * After a successful return, the caller is responsible for calling |
1319 | * spi_unregister_master(). | |
8ae12a0d | 1320 | */ |
e9d5a461 | 1321 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1322 | { |
e44a45ae | 1323 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1324 | struct device *dev = master->dev.parent; |
2b9603a0 | 1325 | struct boardinfo *bi; |
8ae12a0d DB |
1326 | int status = -ENODEV; |
1327 | int dynamic = 0; | |
1328 | ||
0c868461 DB |
1329 | if (!dev) |
1330 | return -ENODEV; | |
1331 | ||
74317984 JCPV |
1332 | status = of_spi_register_master(master); |
1333 | if (status) | |
1334 | return status; | |
1335 | ||
082c8cb4 DB |
1336 | /* 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 | ||
bb29785e GL |
1342 | if ((master->bus_num < 0) && master->dev.of_node) |
1343 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1344 | ||
8ae12a0d | 1345 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1346 | if (master->bus_num < 0) { |
082c8cb4 DB |
1347 | /* FIXME switch to an IDR based scheme, something like |
1348 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1349 | */ | |
8ae12a0d | 1350 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1351 | dynamic = 1; |
8ae12a0d DB |
1352 | } |
1353 | ||
cf32b71e ES |
1354 | spin_lock_init(&master->bus_lock_spinlock); |
1355 | mutex_init(&master->bus_lock_mutex); | |
1356 | master->bus_lock_flag = 0; | |
b158935f | 1357 | init_completion(&master->xfer_completion); |
cf32b71e | 1358 | |
8ae12a0d DB |
1359 | /* register the device, then userspace will see it. |
1360 | * registration fails if the bus ID is in use. | |
1361 | */ | |
35f74fca | 1362 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1363 | status = device_add(&master->dev); |
b885244e | 1364 | if (status < 0) |
8ae12a0d | 1365 | goto done; |
35f74fca | 1366 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1367 | dynamic ? " (dynamic)" : ""); |
1368 | ||
ffbbdd21 LW |
1369 | /* 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) { | |
e93b0724 | 1375 | device_del(&master->dev); |
ffbbdd21 LW |
1376 | goto done; |
1377 | } | |
1378 | } | |
1379 | ||
2b9603a0 FT |
1380 | 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 | ||
64bee4d2 | 1386 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1387 | of_register_spi_devices(master); |
64bee4d2 | 1388 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1389 | done: |
1390 | return status; | |
1391 | } | |
1392 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1393 | ||
666d5b4c MB |
1394 | static 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 | */ | |
1408 | int 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); | |
4b92894e | 1418 | if (!ret) { |
666d5b4c MB |
1419 | *ptr = master; |
1420 | devres_add(dev, ptr); | |
1421 | } else { | |
1422 | devres_free(ptr); | |
1423 | } | |
1424 | ||
1425 | return ret; | |
1426 | } | |
1427 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1428 | ||
34860089 | 1429 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1430 | { |
34860089 | 1431 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1432 | return 0; |
1433 | } | |
1434 | ||
1435 | /** | |
1436 | * spi_unregister_master - unregister SPI master controller | |
1437 | * @master: the master being unregistered | |
33e34dc6 | 1438 | * Context: can sleep |
8ae12a0d DB |
1439 | * |
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 | */ | |
1445 | void spi_unregister_master(struct spi_master *master) | |
1446 | { | |
89fc9a1a JG |
1447 | int dummy; |
1448 | ||
ffbbdd21 LW |
1449 | if (master->queued) { |
1450 | if (spi_destroy_queue(master)) | |
1451 | dev_err(&master->dev, "queue remove failed\n"); | |
1452 | } | |
1453 | ||
2b9603a0 FT |
1454 | mutex_lock(&board_lock); |
1455 | list_del(&master->list); | |
1456 | mutex_unlock(&board_lock); | |
1457 | ||
97dbf37d | 1458 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1459 | device_unregister(&master->dev); |
8ae12a0d DB |
1460 | } |
1461 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1462 | ||
ffbbdd21 LW |
1463 | int 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 | } | |
1477 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1478 | ||
1479 | int 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 | } | |
1492 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1493 | ||
9f3b795a | 1494 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1495 | { |
1496 | struct spi_master *m; | |
9f3b795a | 1497 | const u16 *bus_num = data; |
5ed2c832 DY |
1498 | |
1499 | m = container_of(dev, struct spi_master, dev); | |
1500 | return m->bus_num == *bus_num; | |
1501 | } | |
1502 | ||
8ae12a0d DB |
1503 | /** |
1504 | * spi_busnum_to_master - look up master associated with bus_num | |
1505 | * @bus_num: the master's bus number | |
33e34dc6 | 1506 | * Context: can sleep |
8ae12a0d DB |
1507 | * |
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 | */ | |
1513 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1514 | { | |
49dce689 | 1515 | struct device *dev; |
1e9a51dc | 1516 | struct spi_master *master = NULL; |
5ed2c832 | 1517 | |
695794ae | 1518 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1519 | __spi_master_match); |
1520 | if (dev) | |
1521 | master = container_of(dev, struct spi_master, dev); | |
1522 | /* reference got in class_find_device */ | |
1e9a51dc | 1523 | return master; |
8ae12a0d DB |
1524 | } |
1525 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1526 | ||
1527 | ||
1528 | /*-------------------------------------------------------------------------*/ | |
1529 | ||
7d077197 DB |
1530 | /* 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 | */ | |
1552 | int spi_setup(struct spi_device *spi) | |
1553 | { | |
e7db06b5 | 1554 | unsigned bad_bits; |
caae070c | 1555 | int status = 0; |
7d077197 | 1556 | |
f477b7fb | 1557 | /* 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; | |
e7db06b5 DB |
1570 | /* 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) { | |
eb288a1f | 1575 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1576 | bad_bits); |
1577 | return -EINVAL; | |
1578 | } | |
1579 | ||
7d077197 DB |
1580 | if (!spi->bits_per_word) |
1581 | spi->bits_per_word = 8; | |
1582 | ||
caae070c LD |
1583 | if (spi->master->setup) |
1584 | status = spi->master->setup(spi); | |
7d077197 | 1585 | |
5fe5f05e | 1586 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1587 | (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 | } | |
1597 | EXPORT_SYMBOL_GPL(spi_setup); | |
1598 | ||
cf32b71e ES |
1599 | static int __spi_async(struct spi_device *spi, struct spi_message *message) |
1600 | { | |
1601 | struct spi_master *master = spi->master; | |
e6811d1d | 1602 | struct spi_transfer *xfer; |
cf32b71e | 1603 | |
56ec1978 MB |
1604 | message->spi = spi; |
1605 | ||
1606 | trace_spi_message_submit(message); | |
1607 | ||
24a0013a MB |
1608 | if (list_empty(&message->transfers)) |
1609 | return -EINVAL; | |
1610 | if (!message->complete) | |
1611 | return -EINVAL; | |
1612 | ||
cf32b71e ES |
1613 | /* 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)) { | |
cf32b71e ES |
1620 | 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 | ||
e6811d1d | 1632 | /** |
059b8ffe LD |
1633 | * Set transfer bits_per_word and max speed as spi device default if |
1634 | * it is not set for this transfer. | |
f477b7fb | 1635 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1636 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1637 | */ |
1638 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1639 | message->frame_length += xfer->len; |
e6811d1d LD |
1640 | if (!xfer->bits_per_word) |
1641 | xfer->bits_per_word = spi->bits_per_word; | |
56ede94a | 1642 | if (!xfer->speed_hz) { |
059b8ffe | 1643 | xfer->speed_hz = spi->max_speed_hz; |
56ede94a GJ |
1644 | if (master->max_speed_hz && |
1645 | xfer->speed_hz > master->max_speed_hz) | |
1646 | xfer->speed_hz = master->max_speed_hz; | |
1647 | } | |
1648 | ||
543bb255 SW |
1649 | 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 | } | |
a2fd4f9f MB |
1657 | |
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) | |
d5ee722a | 1663 | return -EINVAL; |
f477b7fb | 1664 | |
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 | */ | |
db90a441 SP |
1674 | 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 | } | |
f477b7fb | 1689 | /* check transfer rx_nbits */ |
db90a441 SP |
1690 | 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 | } | |
e6811d1d LD |
1705 | } |
1706 | ||
cf32b71e ES |
1707 | message->status = -EINPROGRESS; |
1708 | return master->transfer(spi, message); | |
1709 | } | |
1710 | ||
568d0697 DB |
1711 | /** |
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 | */ | |
1740 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
1741 | { | |
1742 | struct spi_master *master = spi->master; | |
cf32b71e ES |
1743 | int ret; |
1744 | unsigned long flags; | |
568d0697 | 1745 | |
cf32b71e | 1746 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 1747 | |
cf32b71e ES |
1748 | if (master->bus_lock_flag) |
1749 | ret = -EBUSY; | |
1750 | else | |
1751 | ret = __spi_async(spi, message); | |
568d0697 | 1752 | |
cf32b71e ES |
1753 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
1754 | ||
1755 | return ret; | |
568d0697 DB |
1756 | } |
1757 | EXPORT_SYMBOL_GPL(spi_async); | |
1758 | ||
cf32b71e ES |
1759 | /** |
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 | */ | |
1788 | int 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 | } | |
1803 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
1804 | ||
7d077197 DB |
1805 | |
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 | ||
5d870c8e AM |
1813 | static void spi_complete(void *arg) |
1814 | { | |
1815 | complete(arg); | |
1816 | } | |
1817 | ||
cf32b71e ES |
1818 | static 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 | ||
8ae12a0d DB |
1844 | /** |
1845 | * spi_sync - blocking/synchronous SPI data transfers | |
1846 | * @spi: device with which data will be exchanged | |
1847 | * @message: describes the data transfers | |
33e34dc6 | 1848 | * Context: can sleep |
8ae12a0d DB |
1849 | * |
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 | * | |
0c868461 DB |
1860 | * Also, the caller is guaranteeing that the memory associated with the |
1861 | * message will not be freed before this call returns. | |
1862 | * | |
9b938b74 | 1863 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
1864 | */ |
1865 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
1866 | { | |
cf32b71e | 1867 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
1868 | } |
1869 | EXPORT_SYMBOL_GPL(spi_sync); | |
1870 | ||
cf32b71e ES |
1871 | /** |
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 | |
25985edc | 1882 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
1883 | * 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 | */ | |
1887 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
1888 | { | |
1889 | return __spi_sync(spi, message, 1); | |
1890 | } | |
1891 | EXPORT_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 | */ | |
1908 | int 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 | } | |
1922 | EXPORT_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 | */ | |
1937 | int 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 | } | |
1945 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
1946 | ||
a9948b61 | 1947 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 1948 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
1949 | |
1950 | static 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 | |
27570497 JP |
1957 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
1958 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 1959 | * Context: can sleep |
8ae12a0d DB |
1960 | * |
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. | |
b885244e | 1964 | * This call may only be used from a context that may sleep. |
8ae12a0d | 1965 | * |
0c868461 | 1966 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
1967 | * portable code should never use this for more than 32 bytes. |
1968 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 1969 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
1970 | */ |
1971 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
1972 | const void *txbuf, unsigned n_tx, |
1973 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 1974 | { |
068f4070 | 1975 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
1976 | |
1977 | int status; | |
1978 | struct spi_message message; | |
bdff549e | 1979 | struct spi_transfer x[2]; |
8ae12a0d DB |
1980 | u8 *local_buf; |
1981 | ||
b3a223ee MB |
1982 | /* 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. | |
8ae12a0d | 1986 | */ |
b3a223ee | 1987 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
1988 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
1989 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
1990 | if (!local_buf) |
1991 | return -ENOMEM; | |
1992 | } else { | |
1993 | local_buf = buf; | |
1994 | } | |
8ae12a0d | 1995 | |
8275c642 | 1996 | spi_message_init(&message); |
5fe5f05e | 1997 | memset(x, 0, sizeof(x)); |
bdff549e DB |
1998 | 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 | } | |
8275c642 | 2006 | |
8ae12a0d | 2007 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2008 | x[0].tx_buf = local_buf; |
2009 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2010 | |
2011 | /* do the i/o */ | |
8ae12a0d | 2012 | status = spi_sync(spi, &message); |
9b938b74 | 2013 | if (status == 0) |
bdff549e | 2014 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2015 | |
bdff549e | 2016 | if (x[0].tx_buf == buf) |
068f4070 | 2017 | mutex_unlock(&lock); |
8ae12a0d DB |
2018 | else |
2019 | kfree(local_buf); | |
2020 | ||
2021 | return status; | |
2022 | } | |
2023 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2024 | ||
2025 | /*-------------------------------------------------------------------------*/ | |
2026 | ||
2027 | static int __init spi_init(void) | |
2028 | { | |
b885244e DB |
2029 | int status; |
2030 | ||
e94b1766 | 2031 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2032 | if (!buf) { |
2033 | status = -ENOMEM; | |
2034 | goto err0; | |
2035 | } | |
2036 | ||
2037 | status = bus_register(&spi_bus_type); | |
2038 | if (status < 0) | |
2039 | goto err1; | |
8ae12a0d | 2040 | |
b885244e DB |
2041 | status = class_register(&spi_master_class); |
2042 | if (status < 0) | |
2043 | goto err2; | |
8ae12a0d | 2044 | return 0; |
b885244e DB |
2045 | |
2046 | err2: | |
2047 | bus_unregister(&spi_bus_type); | |
2048 | err1: | |
2049 | kfree(buf); | |
2050 | buf = NULL; | |
2051 | err0: | |
2052 | return status; | |
8ae12a0d | 2053 | } |
b885244e | 2054 | |
8ae12a0d DB |
2055 | /* board_info is normally registered in arch_initcall(), |
2056 | * but even essential drivers wait till later | |
b885244e DB |
2057 | * |
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. | |
8ae12a0d | 2061 | */ |
673c0c00 | 2062 | postcore_initcall(spi_init); |
8ae12a0d | 2063 |