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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 | ||
b6fb8d3a MW |
373 | static int spi_dev_check(struct device *dev, void *data) |
374 | { | |
375 | struct spi_device *spi = to_spi_device(dev); | |
376 | struct spi_device *new_spi = data; | |
377 | ||
378 | if (spi->master == new_spi->master && | |
379 | spi->chip_select == new_spi->chip_select) | |
380 | return -EBUSY; | |
381 | return 0; | |
382 | } | |
383 | ||
dc87c98e GL |
384 | /** |
385 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
386 | * @spi: spi_device to register | |
387 | * | |
388 | * Companion function to spi_alloc_device. Devices allocated with | |
389 | * spi_alloc_device can be added onto the spi bus with this function. | |
390 | * | |
e48880e0 | 391 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
392 | */ |
393 | int spi_add_device(struct spi_device *spi) | |
394 | { | |
e48880e0 | 395 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
396 | struct spi_master *master = spi->master; |
397 | struct device *dev = master->dev.parent; | |
dc87c98e GL |
398 | int status; |
399 | ||
400 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 401 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
402 | dev_err(dev, "cs%d >= max %d\n", |
403 | spi->chip_select, | |
74317984 | 404 | master->num_chipselect); |
dc87c98e GL |
405 | return -EINVAL; |
406 | } | |
407 | ||
408 | /* Set the bus ID string */ | |
e13ac47b | 409 | spi_dev_set_name(spi); |
e48880e0 DB |
410 | |
411 | /* We need to make sure there's no other device with this | |
412 | * chipselect **BEFORE** we call setup(), else we'll trash | |
413 | * its configuration. Lock against concurrent add() calls. | |
414 | */ | |
415 | mutex_lock(&spi_add_lock); | |
416 | ||
b6fb8d3a MW |
417 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
418 | if (status) { | |
e48880e0 DB |
419 | dev_err(dev, "chipselect %d already in use\n", |
420 | spi->chip_select); | |
e48880e0 DB |
421 | goto done; |
422 | } | |
423 | ||
74317984 JCPV |
424 | if (master->cs_gpios) |
425 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
426 | ||
e48880e0 DB |
427 | /* Drivers may modify this initial i/o setup, but will |
428 | * normally rely on the device being setup. Devices | |
429 | * using SPI_CS_HIGH can't coexist well otherwise... | |
430 | */ | |
7d077197 | 431 | status = spi_setup(spi); |
dc87c98e | 432 | if (status < 0) { |
eb288a1f LW |
433 | dev_err(dev, "can't setup %s, status %d\n", |
434 | dev_name(&spi->dev), status); | |
e48880e0 | 435 | goto done; |
dc87c98e GL |
436 | } |
437 | ||
e48880e0 | 438 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 439 | status = device_add(&spi->dev); |
e48880e0 | 440 | if (status < 0) |
eb288a1f LW |
441 | dev_err(dev, "can't add %s, status %d\n", |
442 | dev_name(&spi->dev), status); | |
e48880e0 | 443 | else |
35f74fca | 444 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 445 | |
e48880e0 DB |
446 | done: |
447 | mutex_unlock(&spi_add_lock); | |
448 | return status; | |
dc87c98e GL |
449 | } |
450 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 451 | |
33e34dc6 DB |
452 | /** |
453 | * spi_new_device - instantiate one new SPI device | |
454 | * @master: Controller to which device is connected | |
455 | * @chip: Describes the SPI device | |
456 | * Context: can sleep | |
457 | * | |
458 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
459 | * after board init creates the hard-wired devices. Some development |
460 | * platforms may not be able to use spi_register_board_info though, and | |
461 | * this is exported so that for example a USB or parport based adapter | |
462 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 DB |
463 | * |
464 | * Returns the new device, or NULL. | |
8ae12a0d | 465 | */ |
e9d5a461 AB |
466 | struct spi_device *spi_new_device(struct spi_master *master, |
467 | struct spi_board_info *chip) | |
8ae12a0d DB |
468 | { |
469 | struct spi_device *proxy; | |
8ae12a0d DB |
470 | int status; |
471 | ||
082c8cb4 DB |
472 | /* NOTE: caller did any chip->bus_num checks necessary. |
473 | * | |
474 | * Also, unless we change the return value convention to use | |
475 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
476 | * suggests syslogged diagnostics are best here (ugh). | |
477 | */ | |
478 | ||
dc87c98e GL |
479 | proxy = spi_alloc_device(master); |
480 | if (!proxy) | |
8ae12a0d DB |
481 | return NULL; |
482 | ||
102eb975 GL |
483 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
484 | ||
8ae12a0d DB |
485 | proxy->chip_select = chip->chip_select; |
486 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 487 | proxy->mode = chip->mode; |
8ae12a0d | 488 | proxy->irq = chip->irq; |
102eb975 | 489 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
490 | proxy->dev.platform_data = (void *) chip->platform_data; |
491 | proxy->controller_data = chip->controller_data; | |
492 | proxy->controller_state = NULL; | |
8ae12a0d | 493 | |
dc87c98e | 494 | status = spi_add_device(proxy); |
8ae12a0d | 495 | if (status < 0) { |
dc87c98e GL |
496 | spi_dev_put(proxy); |
497 | return NULL; | |
8ae12a0d DB |
498 | } |
499 | ||
8ae12a0d DB |
500 | return proxy; |
501 | } | |
502 | EXPORT_SYMBOL_GPL(spi_new_device); | |
503 | ||
2b9603a0 FT |
504 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
505 | struct spi_board_info *bi) | |
506 | { | |
507 | struct spi_device *dev; | |
508 | ||
509 | if (master->bus_num != bi->bus_num) | |
510 | return; | |
511 | ||
512 | dev = spi_new_device(master, bi); | |
513 | if (!dev) | |
514 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
515 | bi->modalias); | |
516 | } | |
517 | ||
33e34dc6 DB |
518 | /** |
519 | * spi_register_board_info - register SPI devices for a given board | |
520 | * @info: array of chip descriptors | |
521 | * @n: how many descriptors are provided | |
522 | * Context: can sleep | |
523 | * | |
8ae12a0d DB |
524 | * Board-specific early init code calls this (probably during arch_initcall) |
525 | * with segments of the SPI device table. Any device nodes are created later, | |
526 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
527 | * this table of devices forever, so that reloading a controller driver will | |
528 | * not make Linux forget about these hard-wired devices. | |
529 | * | |
530 | * Other code can also call this, e.g. a particular add-on board might provide | |
531 | * SPI devices through its expansion connector, so code initializing that board | |
532 | * would naturally declare its SPI devices. | |
533 | * | |
534 | * The board info passed can safely be __initdata ... but be careful of | |
535 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
536 | */ | |
fd4a319b | 537 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 538 | { |
2b9603a0 FT |
539 | struct boardinfo *bi; |
540 | int i; | |
8ae12a0d | 541 | |
2b9603a0 | 542 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
543 | if (!bi) |
544 | return -ENOMEM; | |
8ae12a0d | 545 | |
2b9603a0 FT |
546 | for (i = 0; i < n; i++, bi++, info++) { |
547 | struct spi_master *master; | |
8ae12a0d | 548 | |
2b9603a0 FT |
549 | memcpy(&bi->board_info, info, sizeof(*info)); |
550 | mutex_lock(&board_lock); | |
551 | list_add_tail(&bi->list, &board_list); | |
552 | list_for_each_entry(master, &spi_master_list, list) | |
553 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
554 | mutex_unlock(&board_lock); | |
8ae12a0d | 555 | } |
2b9603a0 FT |
556 | |
557 | return 0; | |
8ae12a0d DB |
558 | } |
559 | ||
560 | /*-------------------------------------------------------------------------*/ | |
561 | ||
b158935f MB |
562 | static void spi_set_cs(struct spi_device *spi, bool enable) |
563 | { | |
564 | if (spi->mode & SPI_CS_HIGH) | |
565 | enable = !enable; | |
566 | ||
567 | if (spi->cs_gpio >= 0) | |
568 | gpio_set_value(spi->cs_gpio, !enable); | |
569 | else if (spi->master->set_cs) | |
570 | spi->master->set_cs(spi, !enable); | |
571 | } | |
572 | ||
573 | /* | |
574 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
575 | * | |
576 | * This is a standard implementation of transfer_one_message() for | |
577 | * drivers which impelment a transfer_one() operation. It provides | |
578 | * standard handling of delays and chip select management. | |
579 | */ | |
580 | static int spi_transfer_one_message(struct spi_master *master, | |
581 | struct spi_message *msg) | |
582 | { | |
583 | struct spi_transfer *xfer; | |
584 | bool cur_cs = true; | |
585 | bool keep_cs = false; | |
586 | int ret = 0; | |
587 | ||
588 | spi_set_cs(msg->spi, true); | |
589 | ||
590 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
591 | trace_spi_transfer_start(msg, xfer); | |
592 | ||
16735d02 | 593 | reinit_completion(&master->xfer_completion); |
b158935f MB |
594 | |
595 | ret = master->transfer_one(master, msg->spi, xfer); | |
596 | if (ret < 0) { | |
597 | dev_err(&msg->spi->dev, | |
598 | "SPI transfer failed: %d\n", ret); | |
599 | goto out; | |
600 | } | |
601 | ||
602 | if (ret > 0) | |
603 | wait_for_completion(&master->xfer_completion); | |
604 | ||
605 | trace_spi_transfer_stop(msg, xfer); | |
606 | ||
607 | if (msg->status != -EINPROGRESS) | |
608 | goto out; | |
609 | ||
610 | if (xfer->delay_usecs) | |
611 | udelay(xfer->delay_usecs); | |
612 | ||
613 | if (xfer->cs_change) { | |
614 | if (list_is_last(&xfer->transfer_list, | |
615 | &msg->transfers)) { | |
616 | keep_cs = true; | |
617 | } else { | |
618 | cur_cs = !cur_cs; | |
619 | spi_set_cs(msg->spi, cur_cs); | |
620 | } | |
621 | } | |
622 | ||
623 | msg->actual_length += xfer->len; | |
624 | } | |
625 | ||
626 | out: | |
627 | if (ret != 0 || !keep_cs) | |
628 | spi_set_cs(msg->spi, false); | |
629 | ||
630 | if (msg->status == -EINPROGRESS) | |
631 | msg->status = ret; | |
632 | ||
633 | spi_finalize_current_message(master); | |
634 | ||
635 | return ret; | |
636 | } | |
637 | ||
638 | /** | |
639 | * spi_finalize_current_transfer - report completion of a transfer | |
640 | * | |
641 | * Called by SPI drivers using the core transfer_one_message() | |
642 | * implementation to notify it that the current interrupt driven | |
9e8f4882 | 643 | * transfer has finished and the next one may be scheduled. |
b158935f MB |
644 | */ |
645 | void spi_finalize_current_transfer(struct spi_master *master) | |
646 | { | |
647 | complete(&master->xfer_completion); | |
648 | } | |
649 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
650 | ||
ffbbdd21 LW |
651 | /** |
652 | * spi_pump_messages - kthread work function which processes spi message queue | |
653 | * @work: pointer to kthread work struct contained in the master struct | |
654 | * | |
655 | * This function checks if there is any spi message in the queue that | |
656 | * needs processing and if so call out to the driver to initialize hardware | |
657 | * and transfer each message. | |
658 | * | |
659 | */ | |
660 | static void spi_pump_messages(struct kthread_work *work) | |
661 | { | |
662 | struct spi_master *master = | |
663 | container_of(work, struct spi_master, pump_messages); | |
664 | unsigned long flags; | |
665 | bool was_busy = false; | |
666 | int ret; | |
667 | ||
668 | /* Lock queue and check for queue work */ | |
669 | spin_lock_irqsave(&master->queue_lock, flags); | |
670 | if (list_empty(&master->queue) || !master->running) { | |
b0b36b86 BF |
671 | if (!master->busy) { |
672 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
673 | return; | |
ffbbdd21 LW |
674 | } |
675 | master->busy = false; | |
676 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
b0b36b86 BF |
677 | if (master->unprepare_transfer_hardware && |
678 | master->unprepare_transfer_hardware(master)) | |
679 | dev_err(&master->dev, | |
680 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
681 | if (master->auto_runtime_pm) { |
682 | pm_runtime_mark_last_busy(master->dev.parent); | |
683 | pm_runtime_put_autosuspend(master->dev.parent); | |
684 | } | |
56ec1978 | 685 | trace_spi_master_idle(master); |
ffbbdd21 LW |
686 | return; |
687 | } | |
688 | ||
689 | /* Make sure we are not already running a message */ | |
690 | if (master->cur_msg) { | |
691 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
692 | return; | |
693 | } | |
694 | /* Extract head of queue */ | |
695 | master->cur_msg = | |
696 | list_entry(master->queue.next, struct spi_message, queue); | |
697 | ||
698 | list_del_init(&master->cur_msg->queue); | |
699 | if (master->busy) | |
700 | was_busy = true; | |
701 | else | |
702 | master->busy = true; | |
703 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
704 | ||
49834de2 MB |
705 | if (!was_busy && master->auto_runtime_pm) { |
706 | ret = pm_runtime_get_sync(master->dev.parent); | |
707 | if (ret < 0) { | |
708 | dev_err(&master->dev, "Failed to power device: %d\n", | |
709 | ret); | |
710 | return; | |
711 | } | |
712 | } | |
713 | ||
56ec1978 MB |
714 | if (!was_busy) |
715 | trace_spi_master_busy(master); | |
716 | ||
7dfd2bd7 | 717 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
718 | ret = master->prepare_transfer_hardware(master); |
719 | if (ret) { | |
720 | dev_err(&master->dev, | |
721 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
722 | |
723 | if (master->auto_runtime_pm) | |
724 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
725 | return; |
726 | } | |
727 | } | |
728 | ||
56ec1978 MB |
729 | trace_spi_message_start(master->cur_msg); |
730 | ||
2841a5fc MB |
731 | if (master->prepare_message) { |
732 | ret = master->prepare_message(master, master->cur_msg); | |
733 | if (ret) { | |
734 | dev_err(&master->dev, | |
735 | "failed to prepare message: %d\n", ret); | |
736 | master->cur_msg->status = ret; | |
737 | spi_finalize_current_message(master); | |
738 | return; | |
739 | } | |
740 | master->cur_msg_prepared = true; | |
741 | } | |
742 | ||
ffbbdd21 LW |
743 | ret = master->transfer_one_message(master, master->cur_msg); |
744 | if (ret) { | |
745 | dev_err(&master->dev, | |
e120cc0d DS |
746 | "failed to transfer one message from queue: %d\n", ret); |
747 | master->cur_msg->status = ret; | |
748 | spi_finalize_current_message(master); | |
ffbbdd21 LW |
749 | return; |
750 | } | |
751 | } | |
752 | ||
753 | static int spi_init_queue(struct spi_master *master) | |
754 | { | |
755 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
756 | ||
757 | INIT_LIST_HEAD(&master->queue); | |
758 | spin_lock_init(&master->queue_lock); | |
759 | ||
760 | master->running = false; | |
761 | master->busy = false; | |
762 | ||
763 | init_kthread_worker(&master->kworker); | |
764 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 765 | &master->kworker, "%s", |
ffbbdd21 LW |
766 | dev_name(&master->dev)); |
767 | if (IS_ERR(master->kworker_task)) { | |
768 | dev_err(&master->dev, "failed to create message pump task\n"); | |
769 | return -ENOMEM; | |
770 | } | |
771 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
772 | ||
773 | /* | |
774 | * Master config will indicate if this controller should run the | |
775 | * message pump with high (realtime) priority to reduce the transfer | |
776 | * latency on the bus by minimising the delay between a transfer | |
777 | * request and the scheduling of the message pump thread. Without this | |
778 | * setting the message pump thread will remain at default priority. | |
779 | */ | |
780 | if (master->rt) { | |
781 | dev_info(&master->dev, | |
782 | "will run message pump with realtime priority\n"); | |
783 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
784 | } | |
785 | ||
786 | return 0; | |
787 | } | |
788 | ||
789 | /** | |
790 | * spi_get_next_queued_message() - called by driver to check for queued | |
791 | * messages | |
792 | * @master: the master to check for queued messages | |
793 | * | |
794 | * If there are more messages in the queue, the next message is returned from | |
795 | * this call. | |
796 | */ | |
797 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
798 | { | |
799 | struct spi_message *next; | |
800 | unsigned long flags; | |
801 | ||
802 | /* get a pointer to the next message, if any */ | |
803 | spin_lock_irqsave(&master->queue_lock, flags); | |
804 | if (list_empty(&master->queue)) | |
805 | next = NULL; | |
806 | else | |
807 | next = list_entry(master->queue.next, | |
808 | struct spi_message, queue); | |
809 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
810 | ||
811 | return next; | |
812 | } | |
813 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
814 | ||
815 | /** | |
816 | * spi_finalize_current_message() - the current message is complete | |
817 | * @master: the master to return the message to | |
818 | * | |
819 | * Called by the driver to notify the core that the message in the front of the | |
820 | * queue is complete and can be removed from the queue. | |
821 | */ | |
822 | void spi_finalize_current_message(struct spi_master *master) | |
823 | { | |
824 | struct spi_message *mesg; | |
825 | unsigned long flags; | |
2841a5fc | 826 | int ret; |
ffbbdd21 LW |
827 | |
828 | spin_lock_irqsave(&master->queue_lock, flags); | |
829 | mesg = master->cur_msg; | |
830 | master->cur_msg = NULL; | |
831 | ||
832 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
833 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
834 | ||
2841a5fc MB |
835 | if (master->cur_msg_prepared && master->unprepare_message) { |
836 | ret = master->unprepare_message(master, mesg); | |
837 | if (ret) { | |
838 | dev_err(&master->dev, | |
839 | "failed to unprepare message: %d\n", ret); | |
840 | } | |
841 | } | |
842 | master->cur_msg_prepared = false; | |
843 | ||
ffbbdd21 LW |
844 | mesg->state = NULL; |
845 | if (mesg->complete) | |
846 | mesg->complete(mesg->context); | |
56ec1978 MB |
847 | |
848 | trace_spi_message_done(mesg); | |
ffbbdd21 LW |
849 | } |
850 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
851 | ||
852 | static int spi_start_queue(struct spi_master *master) | |
853 | { | |
854 | unsigned long flags; | |
855 | ||
856 | spin_lock_irqsave(&master->queue_lock, flags); | |
857 | ||
858 | if (master->running || master->busy) { | |
859 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
860 | return -EBUSY; | |
861 | } | |
862 | ||
863 | master->running = true; | |
864 | master->cur_msg = NULL; | |
865 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
866 | ||
867 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
868 | ||
869 | return 0; | |
870 | } | |
871 | ||
872 | static int spi_stop_queue(struct spi_master *master) | |
873 | { | |
874 | unsigned long flags; | |
875 | unsigned limit = 500; | |
876 | int ret = 0; | |
877 | ||
878 | spin_lock_irqsave(&master->queue_lock, flags); | |
879 | ||
880 | /* | |
881 | * This is a bit lame, but is optimized for the common execution path. | |
882 | * A wait_queue on the master->busy could be used, but then the common | |
883 | * execution path (pump_messages) would be required to call wake_up or | |
884 | * friends on every SPI message. Do this instead. | |
885 | */ | |
886 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
887 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
888 | msleep(10); | |
889 | spin_lock_irqsave(&master->queue_lock, flags); | |
890 | } | |
891 | ||
892 | if (!list_empty(&master->queue) || master->busy) | |
893 | ret = -EBUSY; | |
894 | else | |
895 | master->running = false; | |
896 | ||
897 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
898 | ||
899 | if (ret) { | |
900 | dev_warn(&master->dev, | |
901 | "could not stop message queue\n"); | |
902 | return ret; | |
903 | } | |
904 | return ret; | |
905 | } | |
906 | ||
907 | static int spi_destroy_queue(struct spi_master *master) | |
908 | { | |
909 | int ret; | |
910 | ||
911 | ret = spi_stop_queue(master); | |
912 | ||
913 | /* | |
914 | * flush_kthread_worker will block until all work is done. | |
915 | * If the reason that stop_queue timed out is that the work will never | |
916 | * finish, then it does no good to call flush/stop thread, so | |
917 | * return anyway. | |
918 | */ | |
919 | if (ret) { | |
920 | dev_err(&master->dev, "problem destroying queue\n"); | |
921 | return ret; | |
922 | } | |
923 | ||
924 | flush_kthread_worker(&master->kworker); | |
925 | kthread_stop(master->kworker_task); | |
926 | ||
927 | return 0; | |
928 | } | |
929 | ||
930 | /** | |
931 | * spi_queued_transfer - transfer function for queued transfers | |
932 | * @spi: spi device which is requesting transfer | |
933 | * @msg: spi message which is to handled is queued to driver queue | |
934 | */ | |
935 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
936 | { | |
937 | struct spi_master *master = spi->master; | |
938 | unsigned long flags; | |
939 | ||
940 | spin_lock_irqsave(&master->queue_lock, flags); | |
941 | ||
942 | if (!master->running) { | |
943 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
944 | return -ESHUTDOWN; | |
945 | } | |
946 | msg->actual_length = 0; | |
947 | msg->status = -EINPROGRESS; | |
948 | ||
949 | list_add_tail(&msg->queue, &master->queue); | |
96b3eace | 950 | if (!master->busy) |
ffbbdd21 LW |
951 | queue_kthread_work(&master->kworker, &master->pump_messages); |
952 | ||
953 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
954 | return 0; | |
955 | } | |
956 | ||
957 | static int spi_master_initialize_queue(struct spi_master *master) | |
958 | { | |
959 | int ret; | |
960 | ||
961 | master->queued = true; | |
962 | master->transfer = spi_queued_transfer; | |
b158935f MB |
963 | if (!master->transfer_one_message) |
964 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
965 | |
966 | /* Initialize and start queue */ | |
967 | ret = spi_init_queue(master); | |
968 | if (ret) { | |
969 | dev_err(&master->dev, "problem initializing queue\n"); | |
970 | goto err_init_queue; | |
971 | } | |
972 | ret = spi_start_queue(master); | |
973 | if (ret) { | |
974 | dev_err(&master->dev, "problem starting queue\n"); | |
975 | goto err_start_queue; | |
976 | } | |
977 | ||
978 | return 0; | |
979 | ||
980 | err_start_queue: | |
981 | err_init_queue: | |
982 | spi_destroy_queue(master); | |
983 | return ret; | |
984 | } | |
985 | ||
986 | /*-------------------------------------------------------------------------*/ | |
987 | ||
7cb94361 | 988 | #if defined(CONFIG_OF) |
d57a4282 GL |
989 | /** |
990 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
991 | * @master: Pointer to spi_master device | |
992 | * | |
993 | * Registers an spi_device for each child node of master node which has a 'reg' | |
994 | * property. | |
995 | */ | |
996 | static void of_register_spi_devices(struct spi_master *master) | |
997 | { | |
998 | struct spi_device *spi; | |
999 | struct device_node *nc; | |
d57a4282 | 1000 | int rc; |
89da4293 | 1001 | u32 value; |
d57a4282 GL |
1002 | |
1003 | if (!master->dev.of_node) | |
1004 | return; | |
1005 | ||
f3b6159e | 1006 | for_each_available_child_of_node(master->dev.of_node, nc) { |
d57a4282 GL |
1007 | /* Alloc an spi_device */ |
1008 | spi = spi_alloc_device(master); | |
1009 | if (!spi) { | |
1010 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
1011 | nc->full_name); | |
1012 | spi_dev_put(spi); | |
1013 | continue; | |
1014 | } | |
1015 | ||
1016 | /* Select device driver */ | |
1017 | if (of_modalias_node(nc, spi->modalias, | |
1018 | sizeof(spi->modalias)) < 0) { | |
1019 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
1020 | nc->full_name); | |
1021 | spi_dev_put(spi); | |
1022 | continue; | |
1023 | } | |
1024 | ||
1025 | /* Device address */ | |
89da4293 TP |
1026 | rc = of_property_read_u32(nc, "reg", &value); |
1027 | if (rc) { | |
1028 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
1029 | nc->full_name, rc); | |
d57a4282 GL |
1030 | spi_dev_put(spi); |
1031 | continue; | |
1032 | } | |
89da4293 | 1033 | spi->chip_select = value; |
d57a4282 GL |
1034 | |
1035 | /* Mode (clock phase/polarity/etc.) */ | |
1036 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1037 | spi->mode |= SPI_CPHA; | |
1038 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1039 | spi->mode |= SPI_CPOL; | |
1040 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1041 | spi->mode |= SPI_CS_HIGH; | |
c20151df LPC |
1042 | if (of_find_property(nc, "spi-3wire", NULL)) |
1043 | spi->mode |= SPI_3WIRE; | |
d57a4282 | 1044 | |
f477b7fb | 1045 | /* Device DUAL/QUAD mode */ |
89da4293 TP |
1046 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
1047 | switch (value) { | |
1048 | case 1: | |
a822e99c | 1049 | break; |
89da4293 | 1050 | case 2: |
a822e99c MB |
1051 | spi->mode |= SPI_TX_DUAL; |
1052 | break; | |
89da4293 | 1053 | case 4: |
a822e99c MB |
1054 | spi->mode |= SPI_TX_QUAD; |
1055 | break; | |
1056 | default: | |
1057 | dev_err(&master->dev, | |
a110f93d | 1058 | "spi-tx-bus-width %d not supported\n", |
89da4293 | 1059 | value); |
a822e99c MB |
1060 | spi_dev_put(spi); |
1061 | continue; | |
1062 | } | |
f477b7fb | 1063 | } |
1064 | ||
89da4293 TP |
1065 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
1066 | switch (value) { | |
1067 | case 1: | |
a822e99c | 1068 | break; |
89da4293 | 1069 | case 2: |
a822e99c MB |
1070 | spi->mode |= SPI_RX_DUAL; |
1071 | break; | |
89da4293 | 1072 | case 4: |
a822e99c MB |
1073 | spi->mode |= SPI_RX_QUAD; |
1074 | break; | |
1075 | default: | |
1076 | dev_err(&master->dev, | |
a110f93d | 1077 | "spi-rx-bus-width %d not supported\n", |
89da4293 | 1078 | value); |
a822e99c MB |
1079 | spi_dev_put(spi); |
1080 | continue; | |
1081 | } | |
f477b7fb | 1082 | } |
1083 | ||
d57a4282 | 1084 | /* Device speed */ |
89da4293 TP |
1085 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); |
1086 | if (rc) { | |
1087 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1088 | nc->full_name, rc); | |
d57a4282 GL |
1089 | spi_dev_put(spi); |
1090 | continue; | |
1091 | } | |
89da4293 | 1092 | spi->max_speed_hz = value; |
d57a4282 GL |
1093 | |
1094 | /* IRQ */ | |
1095 | spi->irq = irq_of_parse_and_map(nc, 0); | |
1096 | ||
1097 | /* Store a pointer to the node in the device structure */ | |
1098 | of_node_get(nc); | |
1099 | spi->dev.of_node = nc; | |
1100 | ||
1101 | /* Register the new device */ | |
70fac17c | 1102 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); |
d57a4282 GL |
1103 | rc = spi_add_device(spi); |
1104 | if (rc) { | |
1105 | dev_err(&master->dev, "spi_device register error %s\n", | |
1106 | nc->full_name); | |
1107 | spi_dev_put(spi); | |
1108 | } | |
1109 | ||
1110 | } | |
1111 | } | |
1112 | #else | |
1113 | static void of_register_spi_devices(struct spi_master *master) { } | |
1114 | #endif | |
1115 | ||
64bee4d2 MW |
1116 | #ifdef CONFIG_ACPI |
1117 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1118 | { | |
1119 | struct spi_device *spi = data; | |
1120 | ||
1121 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1122 | struct acpi_resource_spi_serialbus *sb; | |
1123 | ||
1124 | sb = &ares->data.spi_serial_bus; | |
1125 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1126 | spi->chip_select = sb->device_selection; | |
1127 | spi->max_speed_hz = sb->connection_speed; | |
1128 | ||
1129 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1130 | spi->mode |= SPI_CPHA; | |
1131 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1132 | spi->mode |= SPI_CPOL; | |
1133 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1134 | spi->mode |= SPI_CS_HIGH; | |
1135 | } | |
1136 | } else if (spi->irq < 0) { | |
1137 | struct resource r; | |
1138 | ||
1139 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1140 | spi->irq = r.start; | |
1141 | } | |
1142 | ||
1143 | /* Always tell the ACPI core to skip this resource */ | |
1144 | return 1; | |
1145 | } | |
1146 | ||
1147 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1148 | void *data, void **return_value) | |
1149 | { | |
1150 | struct spi_master *master = data; | |
1151 | struct list_head resource_list; | |
1152 | struct acpi_device *adev; | |
1153 | struct spi_device *spi; | |
1154 | int ret; | |
1155 | ||
1156 | if (acpi_bus_get_device(handle, &adev)) | |
1157 | return AE_OK; | |
1158 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1159 | return AE_OK; | |
1160 | ||
1161 | spi = spi_alloc_device(master); | |
1162 | if (!spi) { | |
1163 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1164 | dev_name(&adev->dev)); | |
1165 | return AE_NO_MEMORY; | |
1166 | } | |
1167 | ||
7b199811 | 1168 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1169 | spi->irq = -1; |
1170 | ||
1171 | INIT_LIST_HEAD(&resource_list); | |
1172 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1173 | acpi_spi_add_resource, spi); | |
1174 | acpi_dev_free_resource_list(&resource_list); | |
1175 | ||
1176 | if (ret < 0 || !spi->max_speed_hz) { | |
1177 | spi_dev_put(spi); | |
1178 | return AE_OK; | |
1179 | } | |
1180 | ||
33cf00e5 | 1181 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1182 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1183 | if (spi_add_device(spi)) { |
33cf00e5 | 1184 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1185 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
1186 | dev_name(&adev->dev)); | |
1187 | spi_dev_put(spi); | |
1188 | } | |
1189 | ||
1190 | return AE_OK; | |
1191 | } | |
1192 | ||
1193 | static void acpi_register_spi_devices(struct spi_master *master) | |
1194 | { | |
1195 | acpi_status status; | |
1196 | acpi_handle handle; | |
1197 | ||
29896178 | 1198 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1199 | if (!handle) |
1200 | return; | |
1201 | ||
1202 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1203 | acpi_spi_add_device, NULL, | |
1204 | master, NULL); | |
1205 | if (ACPI_FAILURE(status)) | |
1206 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1207 | } | |
1208 | #else | |
1209 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1210 | #endif /* CONFIG_ACPI */ | |
1211 | ||
49dce689 | 1212 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1213 | { |
1214 | struct spi_master *master; | |
1215 | ||
49dce689 | 1216 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1217 | kfree(master); |
1218 | } | |
1219 | ||
1220 | static struct class spi_master_class = { | |
1221 | .name = "spi_master", | |
1222 | .owner = THIS_MODULE, | |
49dce689 | 1223 | .dev_release = spi_master_release, |
8ae12a0d DB |
1224 | }; |
1225 | ||
1226 | ||
ffbbdd21 | 1227 | |
8ae12a0d DB |
1228 | /** |
1229 | * spi_alloc_master - allocate SPI master controller | |
1230 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1231 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1232 | * memory is in the driver_data field of the returned device, |
0c868461 | 1233 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1234 | * Context: can sleep |
8ae12a0d DB |
1235 | * |
1236 | * This call is used only by SPI master controller drivers, which are the | |
1237 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1238 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1239 | * |
1240 | * This must be called from context that can sleep. It returns the SPI | |
1241 | * master structure on success, else NULL. | |
1242 | * | |
1243 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1244 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1245 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1246 | * leak. | |
8ae12a0d | 1247 | */ |
e9d5a461 | 1248 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1249 | { |
1250 | struct spi_master *master; | |
1251 | ||
0c868461 DB |
1252 | if (!dev) |
1253 | return NULL; | |
1254 | ||
5fe5f05e | 1255 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1256 | if (!master) |
1257 | return NULL; | |
1258 | ||
49dce689 | 1259 | device_initialize(&master->dev); |
1e8a52e1 GL |
1260 | master->bus_num = -1; |
1261 | master->num_chipselect = 1; | |
49dce689 TJ |
1262 | master->dev.class = &spi_master_class; |
1263 | master->dev.parent = get_device(dev); | |
0c868461 | 1264 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1265 | |
1266 | return master; | |
1267 | } | |
1268 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1269 | ||
74317984 JCPV |
1270 | #ifdef CONFIG_OF |
1271 | static int of_spi_register_master(struct spi_master *master) | |
1272 | { | |
e80beb27 | 1273 | int nb, i, *cs; |
74317984 JCPV |
1274 | struct device_node *np = master->dev.of_node; |
1275 | ||
1276 | if (!np) | |
1277 | return 0; | |
1278 | ||
1279 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1280 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1281 | |
8ec5d84e AL |
1282 | /* Return error only for an incorrectly formed cs-gpios property */ |
1283 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1284 | return 0; |
8ec5d84e AL |
1285 | else if (nb < 0) |
1286 | return nb; | |
74317984 JCPV |
1287 | |
1288 | cs = devm_kzalloc(&master->dev, | |
1289 | sizeof(int) * master->num_chipselect, | |
1290 | GFP_KERNEL); | |
1291 | master->cs_gpios = cs; | |
1292 | ||
1293 | if (!master->cs_gpios) | |
1294 | return -ENOMEM; | |
1295 | ||
0da83bb1 | 1296 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1297 | cs[i] = -ENOENT; |
74317984 JCPV |
1298 | |
1299 | for (i = 0; i < nb; i++) | |
1300 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1301 | ||
1302 | return 0; | |
1303 | } | |
1304 | #else | |
1305 | static int of_spi_register_master(struct spi_master *master) | |
1306 | { | |
1307 | return 0; | |
1308 | } | |
1309 | #endif | |
1310 | ||
8ae12a0d DB |
1311 | /** |
1312 | * spi_register_master - register SPI master controller | |
1313 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1314 | * Context: can sleep |
8ae12a0d DB |
1315 | * |
1316 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1317 | * such as the platform bus. The final stage of probe() in that code | |
1318 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1319 | * | |
1320 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1321 | * and board-specific addressing for SPI devices combines those numbers | |
1322 | * with chip select numbers. Since SPI does not directly support dynamic | |
1323 | * device identification, boards need configuration tables telling which | |
1324 | * chip is at which address. | |
1325 | * | |
1326 | * This must be called from context that can sleep. It returns zero on | |
1327 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1328 | * After a successful return, the caller is responsible for calling |
1329 | * spi_unregister_master(). | |
8ae12a0d | 1330 | */ |
e9d5a461 | 1331 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1332 | { |
e44a45ae | 1333 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1334 | struct device *dev = master->dev.parent; |
2b9603a0 | 1335 | struct boardinfo *bi; |
8ae12a0d DB |
1336 | int status = -ENODEV; |
1337 | int dynamic = 0; | |
1338 | ||
0c868461 DB |
1339 | if (!dev) |
1340 | return -ENODEV; | |
1341 | ||
74317984 JCPV |
1342 | status = of_spi_register_master(master); |
1343 | if (status) | |
1344 | return status; | |
1345 | ||
082c8cb4 DB |
1346 | /* even if it's just one always-selected device, there must |
1347 | * be at least one chipselect | |
1348 | */ | |
1349 | if (master->num_chipselect == 0) | |
1350 | return -EINVAL; | |
1351 | ||
bb29785e GL |
1352 | if ((master->bus_num < 0) && master->dev.of_node) |
1353 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1354 | ||
8ae12a0d | 1355 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1356 | if (master->bus_num < 0) { |
082c8cb4 DB |
1357 | /* FIXME switch to an IDR based scheme, something like |
1358 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1359 | */ | |
8ae12a0d | 1360 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1361 | dynamic = 1; |
8ae12a0d DB |
1362 | } |
1363 | ||
cf32b71e ES |
1364 | spin_lock_init(&master->bus_lock_spinlock); |
1365 | mutex_init(&master->bus_lock_mutex); | |
1366 | master->bus_lock_flag = 0; | |
b158935f | 1367 | init_completion(&master->xfer_completion); |
cf32b71e | 1368 | |
8ae12a0d DB |
1369 | /* register the device, then userspace will see it. |
1370 | * registration fails if the bus ID is in use. | |
1371 | */ | |
35f74fca | 1372 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1373 | status = device_add(&master->dev); |
b885244e | 1374 | if (status < 0) |
8ae12a0d | 1375 | goto done; |
35f74fca | 1376 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1377 | dynamic ? " (dynamic)" : ""); |
1378 | ||
ffbbdd21 LW |
1379 | /* If we're using a queued driver, start the queue */ |
1380 | if (master->transfer) | |
1381 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1382 | else { | |
1383 | status = spi_master_initialize_queue(master); | |
1384 | if (status) { | |
e93b0724 | 1385 | device_del(&master->dev); |
ffbbdd21 LW |
1386 | goto done; |
1387 | } | |
1388 | } | |
1389 | ||
2b9603a0 FT |
1390 | mutex_lock(&board_lock); |
1391 | list_add_tail(&master->list, &spi_master_list); | |
1392 | list_for_each_entry(bi, &board_list, list) | |
1393 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1394 | mutex_unlock(&board_lock); | |
1395 | ||
64bee4d2 | 1396 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1397 | of_register_spi_devices(master); |
64bee4d2 | 1398 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1399 | done: |
1400 | return status; | |
1401 | } | |
1402 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1403 | ||
666d5b4c MB |
1404 | static void devm_spi_unregister(struct device *dev, void *res) |
1405 | { | |
1406 | spi_unregister_master(*(struct spi_master **)res); | |
1407 | } | |
1408 | ||
1409 | /** | |
1410 | * dev_spi_register_master - register managed SPI master controller | |
1411 | * @dev: device managing SPI master | |
1412 | * @master: initialized master, originally from spi_alloc_master() | |
1413 | * Context: can sleep | |
1414 | * | |
1415 | * Register a SPI device as with spi_register_master() which will | |
1416 | * automatically be unregister | |
1417 | */ | |
1418 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1419 | { | |
1420 | struct spi_master **ptr; | |
1421 | int ret; | |
1422 | ||
1423 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1424 | if (!ptr) | |
1425 | return -ENOMEM; | |
1426 | ||
1427 | ret = spi_register_master(master); | |
1428 | if (ret != 0) { | |
1429 | *ptr = master; | |
1430 | devres_add(dev, ptr); | |
1431 | } else { | |
1432 | devres_free(ptr); | |
1433 | } | |
1434 | ||
1435 | return ret; | |
1436 | } | |
1437 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1438 | ||
34860089 | 1439 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1440 | { |
34860089 | 1441 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1442 | return 0; |
1443 | } | |
1444 | ||
1445 | /** | |
1446 | * spi_unregister_master - unregister SPI master controller | |
1447 | * @master: the master being unregistered | |
33e34dc6 | 1448 | * Context: can sleep |
8ae12a0d DB |
1449 | * |
1450 | * This call is used only by SPI master controller drivers, which are the | |
1451 | * only ones directly touching chip registers. | |
1452 | * | |
1453 | * This must be called from context that can sleep. | |
1454 | */ | |
1455 | void spi_unregister_master(struct spi_master *master) | |
1456 | { | |
89fc9a1a JG |
1457 | int dummy; |
1458 | ||
ffbbdd21 LW |
1459 | if (master->queued) { |
1460 | if (spi_destroy_queue(master)) | |
1461 | dev_err(&master->dev, "queue remove failed\n"); | |
1462 | } | |
1463 | ||
2b9603a0 FT |
1464 | mutex_lock(&board_lock); |
1465 | list_del(&master->list); | |
1466 | mutex_unlock(&board_lock); | |
1467 | ||
97dbf37d | 1468 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1469 | device_unregister(&master->dev); |
8ae12a0d DB |
1470 | } |
1471 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1472 | ||
ffbbdd21 LW |
1473 | int spi_master_suspend(struct spi_master *master) |
1474 | { | |
1475 | int ret; | |
1476 | ||
1477 | /* Basically no-ops for non-queued masters */ | |
1478 | if (!master->queued) | |
1479 | return 0; | |
1480 | ||
1481 | ret = spi_stop_queue(master); | |
1482 | if (ret) | |
1483 | dev_err(&master->dev, "queue stop failed\n"); | |
1484 | ||
1485 | return ret; | |
1486 | } | |
1487 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1488 | ||
1489 | int spi_master_resume(struct spi_master *master) | |
1490 | { | |
1491 | int ret; | |
1492 | ||
1493 | if (!master->queued) | |
1494 | return 0; | |
1495 | ||
1496 | ret = spi_start_queue(master); | |
1497 | if (ret) | |
1498 | dev_err(&master->dev, "queue restart failed\n"); | |
1499 | ||
1500 | return ret; | |
1501 | } | |
1502 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1503 | ||
9f3b795a | 1504 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1505 | { |
1506 | struct spi_master *m; | |
9f3b795a | 1507 | const u16 *bus_num = data; |
5ed2c832 DY |
1508 | |
1509 | m = container_of(dev, struct spi_master, dev); | |
1510 | return m->bus_num == *bus_num; | |
1511 | } | |
1512 | ||
8ae12a0d DB |
1513 | /** |
1514 | * spi_busnum_to_master - look up master associated with bus_num | |
1515 | * @bus_num: the master's bus number | |
33e34dc6 | 1516 | * Context: can sleep |
8ae12a0d DB |
1517 | * |
1518 | * This call may be used with devices that are registered after | |
1519 | * arch init time. It returns a refcounted pointer to the relevant | |
1520 | * spi_master (which the caller must release), or NULL if there is | |
1521 | * no such master registered. | |
1522 | */ | |
1523 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1524 | { | |
49dce689 | 1525 | struct device *dev; |
1e9a51dc | 1526 | struct spi_master *master = NULL; |
5ed2c832 | 1527 | |
695794ae | 1528 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1529 | __spi_master_match); |
1530 | if (dev) | |
1531 | master = container_of(dev, struct spi_master, dev); | |
1532 | /* reference got in class_find_device */ | |
1e9a51dc | 1533 | return master; |
8ae12a0d DB |
1534 | } |
1535 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1536 | ||
1537 | ||
1538 | /*-------------------------------------------------------------------------*/ | |
1539 | ||
7d077197 DB |
1540 | /* Core methods for SPI master protocol drivers. Some of the |
1541 | * other core methods are currently defined as inline functions. | |
1542 | */ | |
1543 | ||
1544 | /** | |
1545 | * spi_setup - setup SPI mode and clock rate | |
1546 | * @spi: the device whose settings are being modified | |
1547 | * Context: can sleep, and no requests are queued to the device | |
1548 | * | |
1549 | * SPI protocol drivers may need to update the transfer mode if the | |
1550 | * device doesn't work with its default. They may likewise need | |
1551 | * to update clock rates or word sizes from initial values. This function | |
1552 | * changes those settings, and must be called from a context that can sleep. | |
1553 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
1554 | * effect the next time the device is selected and data is transferred to | |
1555 | * or from it. When this function returns, the spi device is deselected. | |
1556 | * | |
1557 | * Note that this call will fail if the protocol driver specifies an option | |
1558 | * that the underlying controller or its driver does not support. For | |
1559 | * example, not all hardware supports wire transfers using nine bit words, | |
1560 | * LSB-first wire encoding, or active-high chipselects. | |
1561 | */ | |
1562 | int spi_setup(struct spi_device *spi) | |
1563 | { | |
e7db06b5 | 1564 | unsigned bad_bits; |
caae070c | 1565 | int status = 0; |
7d077197 | 1566 | |
f477b7fb | 1567 | /* check mode to prevent that DUAL and QUAD set at the same time |
1568 | */ | |
1569 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
1570 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
1571 | dev_err(&spi->dev, | |
1572 | "setup: can not select dual and quad at the same time\n"); | |
1573 | return -EINVAL; | |
1574 | } | |
1575 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
1576 | */ | |
1577 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
1578 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
1579 | return -EINVAL; | |
e7db06b5 DB |
1580 | /* help drivers fail *cleanly* when they need options |
1581 | * that aren't supported with their current master | |
1582 | */ | |
1583 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
1584 | if (bad_bits) { | |
eb288a1f | 1585 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1586 | bad_bits); |
1587 | return -EINVAL; | |
1588 | } | |
1589 | ||
7d077197 DB |
1590 | if (!spi->bits_per_word) |
1591 | spi->bits_per_word = 8; | |
1592 | ||
caae070c LD |
1593 | if (spi->master->setup) |
1594 | status = spi->master->setup(spi); | |
7d077197 | 1595 | |
5fe5f05e | 1596 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1597 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
1598 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
1599 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
1600 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
1601 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
1602 | spi->bits_per_word, spi->max_speed_hz, | |
1603 | status); | |
1604 | ||
1605 | return status; | |
1606 | } | |
1607 | EXPORT_SYMBOL_GPL(spi_setup); | |
1608 | ||
cf32b71e ES |
1609 | static int __spi_async(struct spi_device *spi, struct spi_message *message) |
1610 | { | |
1611 | struct spi_master *master = spi->master; | |
e6811d1d | 1612 | struct spi_transfer *xfer; |
cf32b71e | 1613 | |
56ec1978 MB |
1614 | message->spi = spi; |
1615 | ||
1616 | trace_spi_message_submit(message); | |
1617 | ||
24a0013a MB |
1618 | if (list_empty(&message->transfers)) |
1619 | return -EINVAL; | |
1620 | if (!message->complete) | |
1621 | return -EINVAL; | |
1622 | ||
cf32b71e ES |
1623 | /* Half-duplex links include original MicroWire, and ones with |
1624 | * only one data pin like SPI_3WIRE (switches direction) or where | |
1625 | * either MOSI or MISO is missing. They can also be caused by | |
1626 | * software limitations. | |
1627 | */ | |
1628 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
1629 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
1630 | unsigned flags = master->flags; |
1631 | ||
1632 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
1633 | if (xfer->rx_buf && xfer->tx_buf) | |
1634 | return -EINVAL; | |
1635 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
1636 | return -EINVAL; | |
1637 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
1638 | return -EINVAL; | |
1639 | } | |
1640 | } | |
1641 | ||
e6811d1d | 1642 | /** |
059b8ffe LD |
1643 | * Set transfer bits_per_word and max speed as spi device default if |
1644 | * it is not set for this transfer. | |
f477b7fb | 1645 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1646 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1647 | */ |
1648 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1649 | message->frame_length += xfer->len; |
e6811d1d LD |
1650 | if (!xfer->bits_per_word) |
1651 | xfer->bits_per_word = spi->bits_per_word; | |
56ede94a | 1652 | if (!xfer->speed_hz) { |
059b8ffe | 1653 | xfer->speed_hz = spi->max_speed_hz; |
56ede94a GJ |
1654 | if (master->max_speed_hz && |
1655 | xfer->speed_hz > master->max_speed_hz) | |
1656 | xfer->speed_hz = master->max_speed_hz; | |
1657 | } | |
1658 | ||
543bb255 SW |
1659 | if (master->bits_per_word_mask) { |
1660 | /* Only 32 bits fit in the mask */ | |
1661 | if (xfer->bits_per_word > 32) | |
1662 | return -EINVAL; | |
1663 | if (!(master->bits_per_word_mask & | |
1664 | BIT(xfer->bits_per_word - 1))) | |
1665 | return -EINVAL; | |
1666 | } | |
a2fd4f9f MB |
1667 | |
1668 | if (xfer->speed_hz && master->min_speed_hz && | |
1669 | xfer->speed_hz < master->min_speed_hz) | |
1670 | return -EINVAL; | |
1671 | if (xfer->speed_hz && master->max_speed_hz && | |
1672 | xfer->speed_hz > master->max_speed_hz) | |
d5ee722a | 1673 | return -EINVAL; |
f477b7fb | 1674 | |
1675 | if (xfer->tx_buf && !xfer->tx_nbits) | |
1676 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
1677 | if (xfer->rx_buf && !xfer->rx_nbits) | |
1678 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
1679 | /* check transfer tx/rx_nbits: | |
1680 | * 1. keep the value is not out of single, dual and quad | |
1681 | * 2. keep tx/rx_nbits is contained by mode in spi_device | |
1682 | * 3. if SPI_3WIRE, tx/rx_nbits should be in single | |
1683 | */ | |
db90a441 SP |
1684 | if (xfer->tx_buf) { |
1685 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
1686 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
1687 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
1688 | return -EINVAL; | |
1689 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
1690 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
1691 | return -EINVAL; | |
1692 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
1693 | !(spi->mode & SPI_TX_QUAD)) | |
1694 | return -EINVAL; | |
1695 | if ((spi->mode & SPI_3WIRE) && | |
1696 | (xfer->tx_nbits != SPI_NBITS_SINGLE)) | |
1697 | return -EINVAL; | |
1698 | } | |
f477b7fb | 1699 | /* check transfer rx_nbits */ |
db90a441 SP |
1700 | if (xfer->rx_buf) { |
1701 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
1702 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
1703 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
1704 | return -EINVAL; | |
1705 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
1706 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
1707 | return -EINVAL; | |
1708 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
1709 | !(spi->mode & SPI_RX_QUAD)) | |
1710 | return -EINVAL; | |
1711 | if ((spi->mode & SPI_3WIRE) && | |
1712 | (xfer->rx_nbits != SPI_NBITS_SINGLE)) | |
1713 | return -EINVAL; | |
1714 | } | |
e6811d1d LD |
1715 | } |
1716 | ||
cf32b71e ES |
1717 | message->status = -EINPROGRESS; |
1718 | return master->transfer(spi, message); | |
1719 | } | |
1720 | ||
568d0697 DB |
1721 | /** |
1722 | * spi_async - asynchronous SPI transfer | |
1723 | * @spi: device with which data will be exchanged | |
1724 | * @message: describes the data transfers, including completion callback | |
1725 | * Context: any (irqs may be blocked, etc) | |
1726 | * | |
1727 | * This call may be used in_irq and other contexts which can't sleep, | |
1728 | * as well as from task contexts which can sleep. | |
1729 | * | |
1730 | * The completion callback is invoked in a context which can't sleep. | |
1731 | * Before that invocation, the value of message->status is undefined. | |
1732 | * When the callback is issued, message->status holds either zero (to | |
1733 | * indicate complete success) or a negative error code. After that | |
1734 | * callback returns, the driver which issued the transfer request may | |
1735 | * deallocate the associated memory; it's no longer in use by any SPI | |
1736 | * core or controller driver code. | |
1737 | * | |
1738 | * Note that although all messages to a spi_device are handled in | |
1739 | * FIFO order, messages may go to different devices in other orders. | |
1740 | * Some device might be higher priority, or have various "hard" access | |
1741 | * time requirements, for example. | |
1742 | * | |
1743 | * On detection of any fault during the transfer, processing of | |
1744 | * the entire message is aborted, and the device is deselected. | |
1745 | * Until returning from the associated message completion callback, | |
1746 | * no other spi_message queued to that device will be processed. | |
1747 | * (This rule applies equally to all the synchronous transfer calls, | |
1748 | * which are wrappers around this core asynchronous primitive.) | |
1749 | */ | |
1750 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
1751 | { | |
1752 | struct spi_master *master = spi->master; | |
cf32b71e ES |
1753 | int ret; |
1754 | unsigned long flags; | |
568d0697 | 1755 | |
cf32b71e | 1756 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 1757 | |
cf32b71e ES |
1758 | if (master->bus_lock_flag) |
1759 | ret = -EBUSY; | |
1760 | else | |
1761 | ret = __spi_async(spi, message); | |
568d0697 | 1762 | |
cf32b71e ES |
1763 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
1764 | ||
1765 | return ret; | |
568d0697 DB |
1766 | } |
1767 | EXPORT_SYMBOL_GPL(spi_async); | |
1768 | ||
cf32b71e ES |
1769 | /** |
1770 | * spi_async_locked - version of spi_async with exclusive bus usage | |
1771 | * @spi: device with which data will be exchanged | |
1772 | * @message: describes the data transfers, including completion callback | |
1773 | * Context: any (irqs may be blocked, etc) | |
1774 | * | |
1775 | * This call may be used in_irq and other contexts which can't sleep, | |
1776 | * as well as from task contexts which can sleep. | |
1777 | * | |
1778 | * The completion callback is invoked in a context which can't sleep. | |
1779 | * Before that invocation, the value of message->status is undefined. | |
1780 | * When the callback is issued, message->status holds either zero (to | |
1781 | * indicate complete success) or a negative error code. After that | |
1782 | * callback returns, the driver which issued the transfer request may | |
1783 | * deallocate the associated memory; it's no longer in use by any SPI | |
1784 | * core or controller driver code. | |
1785 | * | |
1786 | * Note that although all messages to a spi_device are handled in | |
1787 | * FIFO order, messages may go to different devices in other orders. | |
1788 | * Some device might be higher priority, or have various "hard" access | |
1789 | * time requirements, for example. | |
1790 | * | |
1791 | * On detection of any fault during the transfer, processing of | |
1792 | * the entire message is aborted, and the device is deselected. | |
1793 | * Until returning from the associated message completion callback, | |
1794 | * no other spi_message queued to that device will be processed. | |
1795 | * (This rule applies equally to all the synchronous transfer calls, | |
1796 | * which are wrappers around this core asynchronous primitive.) | |
1797 | */ | |
1798 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
1799 | { | |
1800 | struct spi_master *master = spi->master; | |
1801 | int ret; | |
1802 | unsigned long flags; | |
1803 | ||
1804 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
1805 | ||
1806 | ret = __spi_async(spi, message); | |
1807 | ||
1808 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
1809 | ||
1810 | return ret; | |
1811 | ||
1812 | } | |
1813 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
1814 | ||
7d077197 DB |
1815 | |
1816 | /*-------------------------------------------------------------------------*/ | |
1817 | ||
1818 | /* Utility methods for SPI master protocol drivers, layered on | |
1819 | * top of the core. Some other utility methods are defined as | |
1820 | * inline functions. | |
1821 | */ | |
1822 | ||
5d870c8e AM |
1823 | static void spi_complete(void *arg) |
1824 | { | |
1825 | complete(arg); | |
1826 | } | |
1827 | ||
cf32b71e ES |
1828 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
1829 | int bus_locked) | |
1830 | { | |
1831 | DECLARE_COMPLETION_ONSTACK(done); | |
1832 | int status; | |
1833 | struct spi_master *master = spi->master; | |
1834 | ||
1835 | message->complete = spi_complete; | |
1836 | message->context = &done; | |
1837 | ||
1838 | if (!bus_locked) | |
1839 | mutex_lock(&master->bus_lock_mutex); | |
1840 | ||
1841 | status = spi_async_locked(spi, message); | |
1842 | ||
1843 | if (!bus_locked) | |
1844 | mutex_unlock(&master->bus_lock_mutex); | |
1845 | ||
1846 | if (status == 0) { | |
1847 | wait_for_completion(&done); | |
1848 | status = message->status; | |
1849 | } | |
1850 | message->context = NULL; | |
1851 | return status; | |
1852 | } | |
1853 | ||
8ae12a0d DB |
1854 | /** |
1855 | * spi_sync - blocking/synchronous SPI data transfers | |
1856 | * @spi: device with which data will be exchanged | |
1857 | * @message: describes the data transfers | |
33e34dc6 | 1858 | * Context: can sleep |
8ae12a0d DB |
1859 | * |
1860 | * This call may only be used from a context that may sleep. The sleep | |
1861 | * is non-interruptible, and has no timeout. Low-overhead controller | |
1862 | * drivers may DMA directly into and out of the message buffers. | |
1863 | * | |
1864 | * Note that the SPI device's chip select is active during the message, | |
1865 | * and then is normally disabled between messages. Drivers for some | |
1866 | * frequently-used devices may want to minimize costs of selecting a chip, | |
1867 | * by leaving it selected in anticipation that the next message will go | |
1868 | * to the same chip. (That may increase power usage.) | |
1869 | * | |
0c868461 DB |
1870 | * Also, the caller is guaranteeing that the memory associated with the |
1871 | * message will not be freed before this call returns. | |
1872 | * | |
9b938b74 | 1873 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
1874 | */ |
1875 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
1876 | { | |
cf32b71e | 1877 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
1878 | } |
1879 | EXPORT_SYMBOL_GPL(spi_sync); | |
1880 | ||
cf32b71e ES |
1881 | /** |
1882 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
1883 | * @spi: device with which data will be exchanged | |
1884 | * @message: describes the data transfers | |
1885 | * Context: can sleep | |
1886 | * | |
1887 | * This call may only be used from a context that may sleep. The sleep | |
1888 | * is non-interruptible, and has no timeout. Low-overhead controller | |
1889 | * drivers may DMA directly into and out of the message buffers. | |
1890 | * | |
1891 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 1892 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
1893 | * be released by a spi_bus_unlock call when the exclusive access is over. |
1894 | * | |
1895 | * It returns zero on success, else a negative error code. | |
1896 | */ | |
1897 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
1898 | { | |
1899 | return __spi_sync(spi, message, 1); | |
1900 | } | |
1901 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
1902 | ||
1903 | /** | |
1904 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
1905 | * @master: SPI bus master that should be locked for exclusive bus access | |
1906 | * Context: can sleep | |
1907 | * | |
1908 | * This call may only be used from a context that may sleep. The sleep | |
1909 | * is non-interruptible, and has no timeout. | |
1910 | * | |
1911 | * This call should be used by drivers that require exclusive access to the | |
1912 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
1913 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
1914 | * and spi_async_locked calls when the SPI bus lock is held. | |
1915 | * | |
1916 | * It returns zero on success, else a negative error code. | |
1917 | */ | |
1918 | int spi_bus_lock(struct spi_master *master) | |
1919 | { | |
1920 | unsigned long flags; | |
1921 | ||
1922 | mutex_lock(&master->bus_lock_mutex); | |
1923 | ||
1924 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
1925 | master->bus_lock_flag = 1; | |
1926 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
1927 | ||
1928 | /* mutex remains locked until spi_bus_unlock is called */ | |
1929 | ||
1930 | return 0; | |
1931 | } | |
1932 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
1933 | ||
1934 | /** | |
1935 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
1936 | * @master: SPI bus master that was locked for exclusive bus access | |
1937 | * Context: can sleep | |
1938 | * | |
1939 | * This call may only be used from a context that may sleep. The sleep | |
1940 | * is non-interruptible, and has no timeout. | |
1941 | * | |
1942 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
1943 | * call. | |
1944 | * | |
1945 | * It returns zero on success, else a negative error code. | |
1946 | */ | |
1947 | int spi_bus_unlock(struct spi_master *master) | |
1948 | { | |
1949 | master->bus_lock_flag = 0; | |
1950 | ||
1951 | mutex_unlock(&master->bus_lock_mutex); | |
1952 | ||
1953 | return 0; | |
1954 | } | |
1955 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
1956 | ||
a9948b61 | 1957 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 1958 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
1959 | |
1960 | static u8 *buf; | |
1961 | ||
1962 | /** | |
1963 | * spi_write_then_read - SPI synchronous write followed by read | |
1964 | * @spi: device with which data will be exchanged | |
1965 | * @txbuf: data to be written (need not be dma-safe) | |
1966 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
1967 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
1968 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 1969 | * Context: can sleep |
8ae12a0d DB |
1970 | * |
1971 | * This performs a half duplex MicroWire style transaction with the | |
1972 | * device, sending txbuf and then reading rxbuf. The return value | |
1973 | * is zero for success, else a negative errno status code. | |
b885244e | 1974 | * This call may only be used from a context that may sleep. |
8ae12a0d | 1975 | * |
0c868461 | 1976 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
1977 | * portable code should never use this for more than 32 bytes. |
1978 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 1979 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
1980 | */ |
1981 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
1982 | const void *txbuf, unsigned n_tx, |
1983 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 1984 | { |
068f4070 | 1985 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
1986 | |
1987 | int status; | |
1988 | struct spi_message message; | |
bdff549e | 1989 | struct spi_transfer x[2]; |
8ae12a0d DB |
1990 | u8 *local_buf; |
1991 | ||
b3a223ee MB |
1992 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
1993 | * copying here, (as a pure convenience thing), but we can | |
1994 | * keep heap costs out of the hot path unless someone else is | |
1995 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 1996 | */ |
b3a223ee | 1997 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
1998 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
1999 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
2000 | if (!local_buf) |
2001 | return -ENOMEM; | |
2002 | } else { | |
2003 | local_buf = buf; | |
2004 | } | |
8ae12a0d | 2005 | |
8275c642 | 2006 | spi_message_init(&message); |
5fe5f05e | 2007 | memset(x, 0, sizeof(x)); |
bdff549e DB |
2008 | if (n_tx) { |
2009 | x[0].len = n_tx; | |
2010 | spi_message_add_tail(&x[0], &message); | |
2011 | } | |
2012 | if (n_rx) { | |
2013 | x[1].len = n_rx; | |
2014 | spi_message_add_tail(&x[1], &message); | |
2015 | } | |
8275c642 | 2016 | |
8ae12a0d | 2017 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2018 | x[0].tx_buf = local_buf; |
2019 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2020 | |
2021 | /* do the i/o */ | |
8ae12a0d | 2022 | status = spi_sync(spi, &message); |
9b938b74 | 2023 | if (status == 0) |
bdff549e | 2024 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2025 | |
bdff549e | 2026 | if (x[0].tx_buf == buf) |
068f4070 | 2027 | mutex_unlock(&lock); |
8ae12a0d DB |
2028 | else |
2029 | kfree(local_buf); | |
2030 | ||
2031 | return status; | |
2032 | } | |
2033 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2034 | ||
2035 | /*-------------------------------------------------------------------------*/ | |
2036 | ||
2037 | static int __init spi_init(void) | |
2038 | { | |
b885244e DB |
2039 | int status; |
2040 | ||
e94b1766 | 2041 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2042 | if (!buf) { |
2043 | status = -ENOMEM; | |
2044 | goto err0; | |
2045 | } | |
2046 | ||
2047 | status = bus_register(&spi_bus_type); | |
2048 | if (status < 0) | |
2049 | goto err1; | |
8ae12a0d | 2050 | |
b885244e DB |
2051 | status = class_register(&spi_master_class); |
2052 | if (status < 0) | |
2053 | goto err2; | |
8ae12a0d | 2054 | return 0; |
b885244e DB |
2055 | |
2056 | err2: | |
2057 | bus_unregister(&spi_bus_type); | |
2058 | err1: | |
2059 | kfree(buf); | |
2060 | buf = NULL; | |
2061 | err0: | |
2062 | return status; | |
8ae12a0d | 2063 | } |
b885244e | 2064 | |
8ae12a0d DB |
2065 | /* board_info is normally registered in arch_initcall(), |
2066 | * but even essential drivers wait till later | |
b885244e DB |
2067 | * |
2068 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2069 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2070 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2071 | */ |
673c0c00 | 2072 | postcore_initcall(spi_init); |
8ae12a0d | 2073 |