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. | |
8ae12a0d DB |
16 | */ |
17 | ||
8ae12a0d | 18 | #include <linux/kernel.h> |
d57a4282 | 19 | #include <linux/kmod.h> |
8ae12a0d DB |
20 | #include <linux/device.h> |
21 | #include <linux/init.h> | |
22 | #include <linux/cache.h> | |
99adef31 MB |
23 | #include <linux/dma-mapping.h> |
24 | #include <linux/dmaengine.h> | |
94040828 | 25 | #include <linux/mutex.h> |
2b7a32f7 | 26 | #include <linux/of_device.h> |
d57a4282 | 27 | #include <linux/of_irq.h> |
86be408b | 28 | #include <linux/clk/clk-conf.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
e0626e38 | 30 | #include <linux/mod_devicetable.h> |
8ae12a0d | 31 | #include <linux/spi/spi.h> |
74317984 | 32 | #include <linux/of_gpio.h> |
3ae22e8c | 33 | #include <linux/pm_runtime.h> |
f48c767c | 34 | #include <linux/pm_domain.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); | |
8c4ff6d0 ZR |
61 | int len; |
62 | ||
63 | len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); | |
64 | if (len != -ENODEV) | |
65 | return len; | |
8ae12a0d | 66 | |
d8e328b3 | 67 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d | 68 | } |
aa7da564 | 69 | static DEVICE_ATTR_RO(modalias); |
8ae12a0d | 70 | |
aa7da564 GKH |
71 | static struct attribute *spi_dev_attrs[] = { |
72 | &dev_attr_modalias.attr, | |
73 | NULL, | |
8ae12a0d | 74 | }; |
aa7da564 | 75 | ATTRIBUTE_GROUPS(spi_dev); |
8ae12a0d DB |
76 | |
77 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, | |
78 | * and the sysfs version makes coldplug work too. | |
79 | */ | |
80 | ||
75368bf6 AV |
81 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
82 | const struct spi_device *sdev) | |
83 | { | |
84 | while (id->name[0]) { | |
85 | if (!strcmp(sdev->modalias, id->name)) | |
86 | return id; | |
87 | id++; | |
88 | } | |
89 | return NULL; | |
90 | } | |
91 | ||
92 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) | |
93 | { | |
94 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); | |
95 | ||
96 | return spi_match_id(sdrv->id_table, sdev); | |
97 | } | |
98 | EXPORT_SYMBOL_GPL(spi_get_device_id); | |
99 | ||
8ae12a0d DB |
100 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
101 | { | |
102 | const struct spi_device *spi = to_spi_device(dev); | |
75368bf6 AV |
103 | const struct spi_driver *sdrv = to_spi_driver(drv); |
104 | ||
2b7a32f7 SA |
105 | /* Attempt an OF style match */ |
106 | if (of_driver_match_device(dev, drv)) | |
107 | return 1; | |
108 | ||
64bee4d2 MW |
109 | /* Then try ACPI */ |
110 | if (acpi_driver_match_device(dev, drv)) | |
111 | return 1; | |
112 | ||
75368bf6 AV |
113 | if (sdrv->id_table) |
114 | return !!spi_match_id(sdrv->id_table, spi); | |
8ae12a0d | 115 | |
35f74fca | 116 | return strcmp(spi->modalias, drv->name) == 0; |
8ae12a0d DB |
117 | } |
118 | ||
7eff2e7a | 119 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
8ae12a0d DB |
120 | { |
121 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
122 | int rc; |
123 | ||
124 | rc = acpi_device_uevent_modalias(dev, env); | |
125 | if (rc != -ENODEV) | |
126 | return rc; | |
8ae12a0d | 127 | |
e0626e38 | 128 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d DB |
129 | return 0; |
130 | } | |
131 | ||
3ae22e8c MB |
132 | #ifdef CONFIG_PM_SLEEP |
133 | static int spi_legacy_suspend(struct device *dev, pm_message_t message) | |
8ae12a0d | 134 | { |
3c72426f | 135 | int value = 0; |
b885244e | 136 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 137 | |
8ae12a0d | 138 | /* suspend will stop irqs and dma; no more i/o */ |
3c72426f DB |
139 | if (drv) { |
140 | if (drv->suspend) | |
141 | value = drv->suspend(to_spi_device(dev), message); | |
142 | else | |
143 | dev_dbg(dev, "... can't suspend\n"); | |
144 | } | |
8ae12a0d DB |
145 | return value; |
146 | } | |
147 | ||
3ae22e8c | 148 | static int spi_legacy_resume(struct device *dev) |
8ae12a0d | 149 | { |
3c72426f | 150 | int value = 0; |
b885244e | 151 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 152 | |
8ae12a0d | 153 | /* resume may restart the i/o queue */ |
3c72426f DB |
154 | if (drv) { |
155 | if (drv->resume) | |
156 | value = drv->resume(to_spi_device(dev)); | |
157 | else | |
158 | dev_dbg(dev, "... can't resume\n"); | |
159 | } | |
8ae12a0d DB |
160 | return value; |
161 | } | |
162 | ||
3ae22e8c MB |
163 | static int spi_pm_suspend(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_suspend(dev); | |
169 | else | |
170 | return spi_legacy_suspend(dev, PMSG_SUSPEND); | |
171 | } | |
172 | ||
173 | static int spi_pm_resume(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_resume(dev); | |
179 | else | |
180 | return spi_legacy_resume(dev); | |
181 | } | |
182 | ||
183 | static int spi_pm_freeze(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_freeze(dev); | |
189 | else | |
190 | return spi_legacy_suspend(dev, PMSG_FREEZE); | |
191 | } | |
192 | ||
193 | static int spi_pm_thaw(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_thaw(dev); | |
199 | else | |
200 | return spi_legacy_resume(dev); | |
201 | } | |
202 | ||
203 | static int spi_pm_poweroff(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_poweroff(dev); | |
209 | else | |
210 | return spi_legacy_suspend(dev, PMSG_HIBERNATE); | |
211 | } | |
212 | ||
213 | static int spi_pm_restore(struct device *dev) | |
214 | { | |
215 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
216 | ||
217 | if (pm) | |
218 | return pm_generic_restore(dev); | |
219 | else | |
220 | return spi_legacy_resume(dev); | |
221 | } | |
8ae12a0d | 222 | #else |
3ae22e8c MB |
223 | #define spi_pm_suspend NULL |
224 | #define spi_pm_resume NULL | |
225 | #define spi_pm_freeze NULL | |
226 | #define spi_pm_thaw NULL | |
227 | #define spi_pm_poweroff NULL | |
228 | #define spi_pm_restore NULL | |
8ae12a0d DB |
229 | #endif |
230 | ||
3ae22e8c MB |
231 | static const struct dev_pm_ops spi_pm = { |
232 | .suspend = spi_pm_suspend, | |
233 | .resume = spi_pm_resume, | |
234 | .freeze = spi_pm_freeze, | |
235 | .thaw = spi_pm_thaw, | |
236 | .poweroff = spi_pm_poweroff, | |
237 | .restore = spi_pm_restore, | |
238 | SET_RUNTIME_PM_OPS( | |
239 | pm_generic_runtime_suspend, | |
240 | pm_generic_runtime_resume, | |
45f0a85c | 241 | NULL |
3ae22e8c MB |
242 | ) |
243 | }; | |
244 | ||
8ae12a0d DB |
245 | struct bus_type spi_bus_type = { |
246 | .name = "spi", | |
aa7da564 | 247 | .dev_groups = spi_dev_groups, |
8ae12a0d DB |
248 | .match = spi_match_device, |
249 | .uevent = spi_uevent, | |
3ae22e8c | 250 | .pm = &spi_pm, |
8ae12a0d DB |
251 | }; |
252 | EXPORT_SYMBOL_GPL(spi_bus_type); | |
253 | ||
b885244e DB |
254 | |
255 | static int spi_drv_probe(struct device *dev) | |
256 | { | |
257 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
258 | int ret; |
259 | ||
86be408b SN |
260 | ret = of_clk_set_defaults(dev->of_node, false); |
261 | if (ret) | |
262 | return ret; | |
263 | ||
676e7c25 UH |
264 | ret = dev_pm_domain_attach(dev, true); |
265 | if (ret != -EPROBE_DEFER) { | |
266 | ret = sdrv->probe(to_spi_device(dev)); | |
267 | if (ret) | |
268 | dev_pm_domain_detach(dev, true); | |
269 | } | |
b885244e | 270 | |
33cf00e5 | 271 | return ret; |
b885244e DB |
272 | } |
273 | ||
274 | static int spi_drv_remove(struct device *dev) | |
275 | { | |
276 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
277 | int ret; |
278 | ||
aec35f4e | 279 | ret = sdrv->remove(to_spi_device(dev)); |
676e7c25 | 280 | dev_pm_domain_detach(dev, true); |
b885244e | 281 | |
33cf00e5 | 282 | return ret; |
b885244e DB |
283 | } |
284 | ||
285 | static void spi_drv_shutdown(struct device *dev) | |
286 | { | |
287 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
288 | ||
289 | sdrv->shutdown(to_spi_device(dev)); | |
290 | } | |
291 | ||
33e34dc6 DB |
292 | /** |
293 | * spi_register_driver - register a SPI driver | |
294 | * @sdrv: the driver to register | |
295 | * Context: can sleep | |
296 | */ | |
b885244e DB |
297 | int spi_register_driver(struct spi_driver *sdrv) |
298 | { | |
299 | sdrv->driver.bus = &spi_bus_type; | |
300 | if (sdrv->probe) | |
301 | sdrv->driver.probe = spi_drv_probe; | |
302 | if (sdrv->remove) | |
303 | sdrv->driver.remove = spi_drv_remove; | |
304 | if (sdrv->shutdown) | |
305 | sdrv->driver.shutdown = spi_drv_shutdown; | |
306 | return driver_register(&sdrv->driver); | |
307 | } | |
308 | EXPORT_SYMBOL_GPL(spi_register_driver); | |
309 | ||
8ae12a0d DB |
310 | /*-------------------------------------------------------------------------*/ |
311 | ||
312 | /* SPI devices should normally not be created by SPI device drivers; that | |
313 | * would make them board-specific. Similarly with SPI master drivers. | |
314 | * Device registration normally goes into like arch/.../mach.../board-YYY.c | |
315 | * with other readonly (flashable) information about mainboard devices. | |
316 | */ | |
317 | ||
318 | struct boardinfo { | |
319 | struct list_head list; | |
2b9603a0 | 320 | struct spi_board_info board_info; |
8ae12a0d DB |
321 | }; |
322 | ||
323 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
324 | static LIST_HEAD(spi_master_list); |
325 | ||
326 | /* | |
327 | * Used to protect add/del opertion for board_info list and | |
328 | * spi_master list, and their matching process | |
329 | */ | |
94040828 | 330 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 331 | |
dc87c98e GL |
332 | /** |
333 | * spi_alloc_device - Allocate a new SPI device | |
334 | * @master: Controller to which device is connected | |
335 | * Context: can sleep | |
336 | * | |
337 | * Allows a driver to allocate and initialize a spi_device without | |
338 | * registering it immediately. This allows a driver to directly | |
339 | * fill the spi_device with device parameters before calling | |
340 | * spi_add_device() on it. | |
341 | * | |
342 | * Caller is responsible to call spi_add_device() on the returned | |
343 | * spi_device structure to add it to the SPI master. If the caller | |
344 | * needs to discard the spi_device without adding it, then it should | |
345 | * call spi_dev_put() on it. | |
346 | * | |
347 | * Returns a pointer to the new device, or NULL. | |
348 | */ | |
349 | struct spi_device *spi_alloc_device(struct spi_master *master) | |
350 | { | |
351 | struct spi_device *spi; | |
dc87c98e GL |
352 | |
353 | if (!spi_master_get(master)) | |
354 | return NULL; | |
355 | ||
5fe5f05e | 356 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e | 357 | if (!spi) { |
dc87c98e GL |
358 | spi_master_put(master); |
359 | return NULL; | |
360 | } | |
361 | ||
362 | spi->master = master; | |
178db7d3 | 363 | spi->dev.parent = &master->dev; |
dc87c98e GL |
364 | spi->dev.bus = &spi_bus_type; |
365 | spi->dev.release = spidev_release; | |
446411e1 | 366 | spi->cs_gpio = -ENOENT; |
dc87c98e GL |
367 | device_initialize(&spi->dev); |
368 | return spi; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
371 | ||
e13ac47b JN |
372 | static void spi_dev_set_name(struct spi_device *spi) |
373 | { | |
374 | struct acpi_device *adev = ACPI_COMPANION(&spi->dev); | |
375 | ||
376 | if (adev) { | |
377 | dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); | |
378 | return; | |
379 | } | |
380 | ||
381 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), | |
382 | spi->chip_select); | |
383 | } | |
384 | ||
b6fb8d3a MW |
385 | static int spi_dev_check(struct device *dev, void *data) |
386 | { | |
387 | struct spi_device *spi = to_spi_device(dev); | |
388 | struct spi_device *new_spi = data; | |
389 | ||
390 | if (spi->master == new_spi->master && | |
391 | spi->chip_select == new_spi->chip_select) | |
392 | return -EBUSY; | |
393 | return 0; | |
394 | } | |
395 | ||
dc87c98e GL |
396 | /** |
397 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
398 | * @spi: spi_device to register | |
399 | * | |
400 | * Companion function to spi_alloc_device. Devices allocated with | |
401 | * spi_alloc_device can be added onto the spi bus with this function. | |
402 | * | |
e48880e0 | 403 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
404 | */ |
405 | int spi_add_device(struct spi_device *spi) | |
406 | { | |
e48880e0 | 407 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
408 | struct spi_master *master = spi->master; |
409 | struct device *dev = master->dev.parent; | |
dc87c98e GL |
410 | int status; |
411 | ||
412 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 413 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
414 | dev_err(dev, "cs%d >= max %d\n", |
415 | spi->chip_select, | |
74317984 | 416 | master->num_chipselect); |
dc87c98e GL |
417 | return -EINVAL; |
418 | } | |
419 | ||
420 | /* Set the bus ID string */ | |
e13ac47b | 421 | spi_dev_set_name(spi); |
e48880e0 DB |
422 | |
423 | /* We need to make sure there's no other device with this | |
424 | * chipselect **BEFORE** we call setup(), else we'll trash | |
425 | * its configuration. Lock against concurrent add() calls. | |
426 | */ | |
427 | mutex_lock(&spi_add_lock); | |
428 | ||
b6fb8d3a MW |
429 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
430 | if (status) { | |
e48880e0 DB |
431 | dev_err(dev, "chipselect %d already in use\n", |
432 | spi->chip_select); | |
e48880e0 DB |
433 | goto done; |
434 | } | |
435 | ||
74317984 JCPV |
436 | if (master->cs_gpios) |
437 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
438 | ||
e48880e0 DB |
439 | /* Drivers may modify this initial i/o setup, but will |
440 | * normally rely on the device being setup. Devices | |
441 | * using SPI_CS_HIGH can't coexist well otherwise... | |
442 | */ | |
7d077197 | 443 | status = spi_setup(spi); |
dc87c98e | 444 | if (status < 0) { |
eb288a1f LW |
445 | dev_err(dev, "can't setup %s, status %d\n", |
446 | dev_name(&spi->dev), status); | |
e48880e0 | 447 | goto done; |
dc87c98e GL |
448 | } |
449 | ||
e48880e0 | 450 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 451 | status = device_add(&spi->dev); |
e48880e0 | 452 | if (status < 0) |
eb288a1f LW |
453 | dev_err(dev, "can't add %s, status %d\n", |
454 | dev_name(&spi->dev), status); | |
e48880e0 | 455 | else |
35f74fca | 456 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 457 | |
e48880e0 DB |
458 | done: |
459 | mutex_unlock(&spi_add_lock); | |
460 | return status; | |
dc87c98e GL |
461 | } |
462 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 463 | |
33e34dc6 DB |
464 | /** |
465 | * spi_new_device - instantiate one new SPI device | |
466 | * @master: Controller to which device is connected | |
467 | * @chip: Describes the SPI device | |
468 | * Context: can sleep | |
469 | * | |
470 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
471 | * after board init creates the hard-wired devices. Some development |
472 | * platforms may not be able to use spi_register_board_info though, and | |
473 | * this is exported so that for example a USB or parport based adapter | |
474 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 DB |
475 | * |
476 | * Returns the new device, or NULL. | |
8ae12a0d | 477 | */ |
e9d5a461 AB |
478 | struct spi_device *spi_new_device(struct spi_master *master, |
479 | struct spi_board_info *chip) | |
8ae12a0d DB |
480 | { |
481 | struct spi_device *proxy; | |
8ae12a0d DB |
482 | int status; |
483 | ||
082c8cb4 DB |
484 | /* NOTE: caller did any chip->bus_num checks necessary. |
485 | * | |
486 | * Also, unless we change the return value convention to use | |
487 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
488 | * suggests syslogged diagnostics are best here (ugh). | |
489 | */ | |
490 | ||
dc87c98e GL |
491 | proxy = spi_alloc_device(master); |
492 | if (!proxy) | |
8ae12a0d DB |
493 | return NULL; |
494 | ||
102eb975 GL |
495 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
496 | ||
8ae12a0d DB |
497 | proxy->chip_select = chip->chip_select; |
498 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 499 | proxy->mode = chip->mode; |
8ae12a0d | 500 | proxy->irq = chip->irq; |
102eb975 | 501 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
502 | proxy->dev.platform_data = (void *) chip->platform_data; |
503 | proxy->controller_data = chip->controller_data; | |
504 | proxy->controller_state = NULL; | |
8ae12a0d | 505 | |
dc87c98e | 506 | status = spi_add_device(proxy); |
8ae12a0d | 507 | if (status < 0) { |
dc87c98e GL |
508 | spi_dev_put(proxy); |
509 | return NULL; | |
8ae12a0d DB |
510 | } |
511 | ||
8ae12a0d DB |
512 | return proxy; |
513 | } | |
514 | EXPORT_SYMBOL_GPL(spi_new_device); | |
515 | ||
2b9603a0 FT |
516 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
517 | struct spi_board_info *bi) | |
518 | { | |
519 | struct spi_device *dev; | |
520 | ||
521 | if (master->bus_num != bi->bus_num) | |
522 | return; | |
523 | ||
524 | dev = spi_new_device(master, bi); | |
525 | if (!dev) | |
526 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
527 | bi->modalias); | |
528 | } | |
529 | ||
33e34dc6 DB |
530 | /** |
531 | * spi_register_board_info - register SPI devices for a given board | |
532 | * @info: array of chip descriptors | |
533 | * @n: how many descriptors are provided | |
534 | * Context: can sleep | |
535 | * | |
8ae12a0d DB |
536 | * Board-specific early init code calls this (probably during arch_initcall) |
537 | * with segments of the SPI device table. Any device nodes are created later, | |
538 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
539 | * this table of devices forever, so that reloading a controller driver will | |
540 | * not make Linux forget about these hard-wired devices. | |
541 | * | |
542 | * Other code can also call this, e.g. a particular add-on board might provide | |
543 | * SPI devices through its expansion connector, so code initializing that board | |
544 | * would naturally declare its SPI devices. | |
545 | * | |
546 | * The board info passed can safely be __initdata ... but be careful of | |
547 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
548 | */ | |
fd4a319b | 549 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 550 | { |
2b9603a0 FT |
551 | struct boardinfo *bi; |
552 | int i; | |
8ae12a0d | 553 | |
c7908a37 XL |
554 | if (!n) |
555 | return -EINVAL; | |
556 | ||
2b9603a0 | 557 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
558 | if (!bi) |
559 | return -ENOMEM; | |
8ae12a0d | 560 | |
2b9603a0 FT |
561 | for (i = 0; i < n; i++, bi++, info++) { |
562 | struct spi_master *master; | |
8ae12a0d | 563 | |
2b9603a0 FT |
564 | memcpy(&bi->board_info, info, sizeof(*info)); |
565 | mutex_lock(&board_lock); | |
566 | list_add_tail(&bi->list, &board_list); | |
567 | list_for_each_entry(master, &spi_master_list, list) | |
568 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
569 | mutex_unlock(&board_lock); | |
8ae12a0d | 570 | } |
2b9603a0 FT |
571 | |
572 | return 0; | |
8ae12a0d DB |
573 | } |
574 | ||
575 | /*-------------------------------------------------------------------------*/ | |
576 | ||
b158935f MB |
577 | static void spi_set_cs(struct spi_device *spi, bool enable) |
578 | { | |
579 | if (spi->mode & SPI_CS_HIGH) | |
580 | enable = !enable; | |
581 | ||
582 | if (spi->cs_gpio >= 0) | |
583 | gpio_set_value(spi->cs_gpio, !enable); | |
584 | else if (spi->master->set_cs) | |
585 | spi->master->set_cs(spi, !enable); | |
586 | } | |
587 | ||
2de440f5 | 588 | #ifdef CONFIG_HAS_DMA |
6ad45a27 MB |
589 | static int spi_map_buf(struct spi_master *master, struct device *dev, |
590 | struct sg_table *sgt, void *buf, size_t len, | |
591 | enum dma_data_direction dir) | |
592 | { | |
593 | const bool vmalloced_buf = is_vmalloc_addr(buf); | |
594 | const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len; | |
595 | const int sgs = DIV_ROUND_UP(len, desc_len); | |
596 | struct page *vm_page; | |
597 | void *sg_buf; | |
598 | size_t min; | |
599 | int i, ret; | |
600 | ||
601 | ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); | |
602 | if (ret != 0) | |
603 | return ret; | |
604 | ||
605 | for (i = 0; i < sgs; i++) { | |
606 | min = min_t(size_t, len, desc_len); | |
607 | ||
608 | if (vmalloced_buf) { | |
609 | vm_page = vmalloc_to_page(buf); | |
610 | if (!vm_page) { | |
611 | sg_free_table(sgt); | |
612 | return -ENOMEM; | |
613 | } | |
c1aefbdd CK |
614 | sg_set_page(&sgt->sgl[i], vm_page, |
615 | min, offset_in_page(buf)); | |
6ad45a27 MB |
616 | } else { |
617 | sg_buf = buf; | |
c1aefbdd | 618 | sg_set_buf(&sgt->sgl[i], sg_buf, min); |
6ad45a27 MB |
619 | } |
620 | ||
6ad45a27 MB |
621 | |
622 | buf += min; | |
623 | len -= min; | |
624 | } | |
625 | ||
626 | ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); | |
89e4b66a GU |
627 | if (!ret) |
628 | ret = -ENOMEM; | |
6ad45a27 MB |
629 | if (ret < 0) { |
630 | sg_free_table(sgt); | |
631 | return ret; | |
632 | } | |
633 | ||
634 | sgt->nents = ret; | |
635 | ||
636 | return 0; | |
637 | } | |
638 | ||
639 | static void spi_unmap_buf(struct spi_master *master, struct device *dev, | |
640 | struct sg_table *sgt, enum dma_data_direction dir) | |
641 | { | |
642 | if (sgt->orig_nents) { | |
643 | dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); | |
644 | sg_free_table(sgt); | |
645 | } | |
646 | } | |
647 | ||
2de440f5 | 648 | static int __spi_map_msg(struct spi_master *master, struct spi_message *msg) |
99adef31 | 649 | { |
99adef31 MB |
650 | struct device *tx_dev, *rx_dev; |
651 | struct spi_transfer *xfer; | |
6ad45a27 | 652 | int ret; |
3a2eba9b | 653 | |
6ad45a27 | 654 | if (!master->can_dma) |
99adef31 MB |
655 | return 0; |
656 | ||
3fc25421 GU |
657 | tx_dev = master->dma_tx->device->dev; |
658 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
659 | |
660 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
661 | if (!master->can_dma(master, msg->spi, xfer)) | |
662 | continue; | |
663 | ||
664 | if (xfer->tx_buf != NULL) { | |
6ad45a27 MB |
665 | ret = spi_map_buf(master, tx_dev, &xfer->tx_sg, |
666 | (void *)xfer->tx_buf, xfer->len, | |
667 | DMA_TO_DEVICE); | |
668 | if (ret != 0) | |
669 | return ret; | |
99adef31 MB |
670 | } |
671 | ||
672 | if (xfer->rx_buf != NULL) { | |
6ad45a27 MB |
673 | ret = spi_map_buf(master, rx_dev, &xfer->rx_sg, |
674 | xfer->rx_buf, xfer->len, | |
675 | DMA_FROM_DEVICE); | |
676 | if (ret != 0) { | |
677 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, | |
678 | DMA_TO_DEVICE); | |
679 | return ret; | |
99adef31 MB |
680 | } |
681 | } | |
682 | } | |
683 | ||
684 | master->cur_msg_mapped = true; | |
685 | ||
686 | return 0; | |
687 | } | |
688 | ||
689 | static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg) | |
690 | { | |
691 | struct spi_transfer *xfer; | |
692 | struct device *tx_dev, *rx_dev; | |
693 | ||
6ad45a27 | 694 | if (!master->cur_msg_mapped || !master->can_dma) |
99adef31 MB |
695 | return 0; |
696 | ||
3fc25421 GU |
697 | tx_dev = master->dma_tx->device->dev; |
698 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
699 | |
700 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
701 | if (!master->can_dma(master, msg->spi, xfer)) | |
702 | continue; | |
703 | ||
6ad45a27 MB |
704 | spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
705 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); | |
99adef31 MB |
706 | } |
707 | ||
708 | return 0; | |
709 | } | |
2de440f5 GU |
710 | #else /* !CONFIG_HAS_DMA */ |
711 | static inline int __spi_map_msg(struct spi_master *master, | |
712 | struct spi_message *msg) | |
713 | { | |
714 | return 0; | |
715 | } | |
716 | ||
717 | static inline int spi_unmap_msg(struct spi_master *master, | |
718 | struct spi_message *msg) | |
719 | { | |
720 | return 0; | |
721 | } | |
722 | #endif /* !CONFIG_HAS_DMA */ | |
723 | ||
724 | static int spi_map_msg(struct spi_master *master, struct spi_message *msg) | |
725 | { | |
726 | struct spi_transfer *xfer; | |
727 | void *tmp; | |
728 | unsigned int max_tx, max_rx; | |
729 | ||
730 | if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) { | |
731 | max_tx = 0; | |
732 | max_rx = 0; | |
733 | ||
734 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
735 | if ((master->flags & SPI_MASTER_MUST_TX) && | |
736 | !xfer->tx_buf) | |
737 | max_tx = max(xfer->len, max_tx); | |
738 | if ((master->flags & SPI_MASTER_MUST_RX) && | |
739 | !xfer->rx_buf) | |
740 | max_rx = max(xfer->len, max_rx); | |
741 | } | |
742 | ||
743 | if (max_tx) { | |
744 | tmp = krealloc(master->dummy_tx, max_tx, | |
745 | GFP_KERNEL | GFP_DMA); | |
746 | if (!tmp) | |
747 | return -ENOMEM; | |
748 | master->dummy_tx = tmp; | |
749 | memset(tmp, 0, max_tx); | |
750 | } | |
751 | ||
752 | if (max_rx) { | |
753 | tmp = krealloc(master->dummy_rx, max_rx, | |
754 | GFP_KERNEL | GFP_DMA); | |
755 | if (!tmp) | |
756 | return -ENOMEM; | |
757 | master->dummy_rx = tmp; | |
758 | } | |
759 | ||
760 | if (max_tx || max_rx) { | |
761 | list_for_each_entry(xfer, &msg->transfers, | |
762 | transfer_list) { | |
763 | if (!xfer->tx_buf) | |
764 | xfer->tx_buf = master->dummy_tx; | |
765 | if (!xfer->rx_buf) | |
766 | xfer->rx_buf = master->dummy_rx; | |
767 | } | |
768 | } | |
769 | } | |
770 | ||
771 | return __spi_map_msg(master, msg); | |
772 | } | |
99adef31 | 773 | |
b158935f MB |
774 | /* |
775 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
776 | * | |
777 | * This is a standard implementation of transfer_one_message() for | |
778 | * drivers which impelment a transfer_one() operation. It provides | |
779 | * standard handling of delays and chip select management. | |
780 | */ | |
781 | static int spi_transfer_one_message(struct spi_master *master, | |
782 | struct spi_message *msg) | |
783 | { | |
784 | struct spi_transfer *xfer; | |
b158935f MB |
785 | bool keep_cs = false; |
786 | int ret = 0; | |
682a71b2 | 787 | unsigned long ms = 1; |
b158935f MB |
788 | |
789 | spi_set_cs(msg->spi, true); | |
790 | ||
791 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
792 | trace_spi_transfer_start(msg, xfer); | |
793 | ||
38ec10f6 MB |
794 | if (xfer->tx_buf || xfer->rx_buf) { |
795 | reinit_completion(&master->xfer_completion); | |
b158935f | 796 | |
38ec10f6 MB |
797 | ret = master->transfer_one(master, msg->spi, xfer); |
798 | if (ret < 0) { | |
799 | dev_err(&msg->spi->dev, | |
800 | "SPI transfer failed: %d\n", ret); | |
801 | goto out; | |
802 | } | |
b158935f | 803 | |
38ec10f6 MB |
804 | if (ret > 0) { |
805 | ret = 0; | |
806 | ms = xfer->len * 8 * 1000 / xfer->speed_hz; | |
807 | ms += ms + 100; /* some tolerance */ | |
16a0ce4e | 808 | |
38ec10f6 MB |
809 | ms = wait_for_completion_timeout(&master->xfer_completion, |
810 | msecs_to_jiffies(ms)); | |
811 | } | |
16a0ce4e | 812 | |
38ec10f6 MB |
813 | if (ms == 0) { |
814 | dev_err(&msg->spi->dev, | |
815 | "SPI transfer timed out\n"); | |
816 | msg->status = -ETIMEDOUT; | |
817 | } | |
818 | } else { | |
819 | if (xfer->len) | |
820 | dev_err(&msg->spi->dev, | |
821 | "Bufferless transfer has length %u\n", | |
822 | xfer->len); | |
13a42798 | 823 | } |
b158935f MB |
824 | |
825 | trace_spi_transfer_stop(msg, xfer); | |
826 | ||
827 | if (msg->status != -EINPROGRESS) | |
828 | goto out; | |
829 | ||
830 | if (xfer->delay_usecs) | |
831 | udelay(xfer->delay_usecs); | |
832 | ||
833 | if (xfer->cs_change) { | |
834 | if (list_is_last(&xfer->transfer_list, | |
835 | &msg->transfers)) { | |
836 | keep_cs = true; | |
837 | } else { | |
0b73aa63 MB |
838 | spi_set_cs(msg->spi, false); |
839 | udelay(10); | |
840 | spi_set_cs(msg->spi, true); | |
b158935f MB |
841 | } |
842 | } | |
843 | ||
844 | msg->actual_length += xfer->len; | |
845 | } | |
846 | ||
847 | out: | |
848 | if (ret != 0 || !keep_cs) | |
849 | spi_set_cs(msg->spi, false); | |
850 | ||
851 | if (msg->status == -EINPROGRESS) | |
852 | msg->status = ret; | |
853 | ||
854 | spi_finalize_current_message(master); | |
855 | ||
856 | return ret; | |
857 | } | |
858 | ||
859 | /** | |
860 | * spi_finalize_current_transfer - report completion of a transfer | |
2c675689 | 861 | * @master: the master reporting completion |
b158935f MB |
862 | * |
863 | * Called by SPI drivers using the core transfer_one_message() | |
864 | * implementation to notify it that the current interrupt driven | |
9e8f4882 | 865 | * transfer has finished and the next one may be scheduled. |
b158935f MB |
866 | */ |
867 | void spi_finalize_current_transfer(struct spi_master *master) | |
868 | { | |
869 | complete(&master->xfer_completion); | |
870 | } | |
871 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
872 | ||
ffbbdd21 | 873 | /** |
fc9e0f71 MB |
874 | * __spi_pump_messages - function which processes spi message queue |
875 | * @master: master to process queue for | |
876 | * @in_kthread: true if we are in the context of the message pump thread | |
ffbbdd21 LW |
877 | * |
878 | * This function checks if there is any spi message in the queue that | |
879 | * needs processing and if so call out to the driver to initialize hardware | |
880 | * and transfer each message. | |
881 | * | |
0461a414 MB |
882 | * Note that it is called both from the kthread itself and also from |
883 | * inside spi_sync(); the queue extraction handling at the top of the | |
884 | * function should deal with this safely. | |
ffbbdd21 | 885 | */ |
fc9e0f71 | 886 | static void __spi_pump_messages(struct spi_master *master, bool in_kthread) |
ffbbdd21 | 887 | { |
ffbbdd21 LW |
888 | unsigned long flags; |
889 | bool was_busy = false; | |
890 | int ret; | |
891 | ||
983aee5d | 892 | /* Lock queue */ |
ffbbdd21 | 893 | spin_lock_irqsave(&master->queue_lock, flags); |
983aee5d MB |
894 | |
895 | /* Make sure we are not already running a message */ | |
896 | if (master->cur_msg) { | |
897 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
898 | return; | |
899 | } | |
900 | ||
0461a414 MB |
901 | /* If another context is idling the device then defer */ |
902 | if (master->idling) { | |
903 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
904 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
905 | return; | |
906 | } | |
907 | ||
983aee5d | 908 | /* Check if the queue is idle */ |
ffbbdd21 | 909 | if (list_empty(&master->queue) || !master->running) { |
b0b36b86 BF |
910 | if (!master->busy) { |
911 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
912 | return; | |
ffbbdd21 | 913 | } |
fc9e0f71 MB |
914 | |
915 | /* Only do teardown in the thread */ | |
916 | if (!in_kthread) { | |
917 | queue_kthread_work(&master->kworker, | |
918 | &master->pump_messages); | |
919 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
920 | return; | |
921 | } | |
922 | ||
ffbbdd21 | 923 | master->busy = false; |
0461a414 | 924 | master->idling = true; |
ffbbdd21 | 925 | spin_unlock_irqrestore(&master->queue_lock, flags); |
0461a414 | 926 | |
3a2eba9b MB |
927 | kfree(master->dummy_rx); |
928 | master->dummy_rx = NULL; | |
929 | kfree(master->dummy_tx); | |
930 | master->dummy_tx = NULL; | |
b0b36b86 BF |
931 | if (master->unprepare_transfer_hardware && |
932 | master->unprepare_transfer_hardware(master)) | |
933 | dev_err(&master->dev, | |
934 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
935 | if (master->auto_runtime_pm) { |
936 | pm_runtime_mark_last_busy(master->dev.parent); | |
937 | pm_runtime_put_autosuspend(master->dev.parent); | |
938 | } | |
56ec1978 | 939 | trace_spi_master_idle(master); |
ffbbdd21 | 940 | |
0461a414 MB |
941 | spin_lock_irqsave(&master->queue_lock, flags); |
942 | master->idling = false; | |
ffbbdd21 LW |
943 | spin_unlock_irqrestore(&master->queue_lock, flags); |
944 | return; | |
945 | } | |
ffbbdd21 | 946 | |
ffbbdd21 LW |
947 | /* Extract head of queue */ |
948 | master->cur_msg = | |
a89e2d27 | 949 | list_first_entry(&master->queue, struct spi_message, queue); |
ffbbdd21 LW |
950 | |
951 | list_del_init(&master->cur_msg->queue); | |
952 | if (master->busy) | |
953 | was_busy = true; | |
954 | else | |
955 | master->busy = true; | |
956 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
957 | ||
49834de2 MB |
958 | if (!was_busy && master->auto_runtime_pm) { |
959 | ret = pm_runtime_get_sync(master->dev.parent); | |
960 | if (ret < 0) { | |
961 | dev_err(&master->dev, "Failed to power device: %d\n", | |
962 | ret); | |
963 | return; | |
964 | } | |
965 | } | |
966 | ||
56ec1978 MB |
967 | if (!was_busy) |
968 | trace_spi_master_busy(master); | |
969 | ||
7dfd2bd7 | 970 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
971 | ret = master->prepare_transfer_hardware(master); |
972 | if (ret) { | |
973 | dev_err(&master->dev, | |
974 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
975 | |
976 | if (master->auto_runtime_pm) | |
977 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
978 | return; |
979 | } | |
980 | } | |
981 | ||
56ec1978 MB |
982 | trace_spi_message_start(master->cur_msg); |
983 | ||
2841a5fc MB |
984 | if (master->prepare_message) { |
985 | ret = master->prepare_message(master, master->cur_msg); | |
986 | if (ret) { | |
987 | dev_err(&master->dev, | |
988 | "failed to prepare message: %d\n", ret); | |
989 | master->cur_msg->status = ret; | |
990 | spi_finalize_current_message(master); | |
991 | return; | |
992 | } | |
993 | master->cur_msg_prepared = true; | |
994 | } | |
995 | ||
99adef31 MB |
996 | ret = spi_map_msg(master, master->cur_msg); |
997 | if (ret) { | |
998 | master->cur_msg->status = ret; | |
999 | spi_finalize_current_message(master); | |
1000 | return; | |
1001 | } | |
1002 | ||
ffbbdd21 LW |
1003 | ret = master->transfer_one_message(master, master->cur_msg); |
1004 | if (ret) { | |
1005 | dev_err(&master->dev, | |
1f802f82 | 1006 | "failed to transfer one message from queue\n"); |
ffbbdd21 LW |
1007 | return; |
1008 | } | |
1009 | } | |
1010 | ||
fc9e0f71 MB |
1011 | /** |
1012 | * spi_pump_messages - kthread work function which processes spi message queue | |
1013 | * @work: pointer to kthread work struct contained in the master struct | |
1014 | */ | |
1015 | static void spi_pump_messages(struct kthread_work *work) | |
1016 | { | |
1017 | struct spi_master *master = | |
1018 | container_of(work, struct spi_master, pump_messages); | |
1019 | ||
1020 | __spi_pump_messages(master, true); | |
1021 | } | |
1022 | ||
ffbbdd21 LW |
1023 | static int spi_init_queue(struct spi_master *master) |
1024 | { | |
1025 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
1026 | ||
ffbbdd21 LW |
1027 | master->running = false; |
1028 | master->busy = false; | |
1029 | ||
1030 | init_kthread_worker(&master->kworker); | |
1031 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 1032 | &master->kworker, "%s", |
ffbbdd21 LW |
1033 | dev_name(&master->dev)); |
1034 | if (IS_ERR(master->kworker_task)) { | |
1035 | dev_err(&master->dev, "failed to create message pump task\n"); | |
98a8f5a0 | 1036 | return PTR_ERR(master->kworker_task); |
ffbbdd21 LW |
1037 | } |
1038 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
1039 | ||
1040 | /* | |
1041 | * Master config will indicate if this controller should run the | |
1042 | * message pump with high (realtime) priority to reduce the transfer | |
1043 | * latency on the bus by minimising the delay between a transfer | |
1044 | * request and the scheduling of the message pump thread. Without this | |
1045 | * setting the message pump thread will remain at default priority. | |
1046 | */ | |
1047 | if (master->rt) { | |
1048 | dev_info(&master->dev, | |
1049 | "will run message pump with realtime priority\n"); | |
1050 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
1051 | } | |
1052 | ||
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | /** | |
1057 | * spi_get_next_queued_message() - called by driver to check for queued | |
1058 | * messages | |
1059 | * @master: the master to check for queued messages | |
1060 | * | |
1061 | * If there are more messages in the queue, the next message is returned from | |
1062 | * this call. | |
1063 | */ | |
1064 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
1065 | { | |
1066 | struct spi_message *next; | |
1067 | unsigned long flags; | |
1068 | ||
1069 | /* get a pointer to the next message, if any */ | |
1070 | spin_lock_irqsave(&master->queue_lock, flags); | |
1cfd97f9 AL |
1071 | next = list_first_entry_or_null(&master->queue, struct spi_message, |
1072 | queue); | |
ffbbdd21 LW |
1073 | spin_unlock_irqrestore(&master->queue_lock, flags); |
1074 | ||
1075 | return next; | |
1076 | } | |
1077 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
1078 | ||
1079 | /** | |
1080 | * spi_finalize_current_message() - the current message is complete | |
1081 | * @master: the master to return the message to | |
1082 | * | |
1083 | * Called by the driver to notify the core that the message in the front of the | |
1084 | * queue is complete and can be removed from the queue. | |
1085 | */ | |
1086 | void spi_finalize_current_message(struct spi_master *master) | |
1087 | { | |
1088 | struct spi_message *mesg; | |
1089 | unsigned long flags; | |
2841a5fc | 1090 | int ret; |
ffbbdd21 LW |
1091 | |
1092 | spin_lock_irqsave(&master->queue_lock, flags); | |
1093 | mesg = master->cur_msg; | |
1094 | master->cur_msg = NULL; | |
1095 | ||
1096 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1097 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1098 | ||
99adef31 MB |
1099 | spi_unmap_msg(master, mesg); |
1100 | ||
2841a5fc MB |
1101 | if (master->cur_msg_prepared && master->unprepare_message) { |
1102 | ret = master->unprepare_message(master, mesg); | |
1103 | if (ret) { | |
1104 | dev_err(&master->dev, | |
1105 | "failed to unprepare message: %d\n", ret); | |
1106 | } | |
1107 | } | |
1108 | master->cur_msg_prepared = false; | |
1109 | ||
ffbbdd21 LW |
1110 | mesg->state = NULL; |
1111 | if (mesg->complete) | |
1112 | mesg->complete(mesg->context); | |
56ec1978 MB |
1113 | |
1114 | trace_spi_message_done(mesg); | |
ffbbdd21 LW |
1115 | } |
1116 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
1117 | ||
1118 | static int spi_start_queue(struct spi_master *master) | |
1119 | { | |
1120 | unsigned long flags; | |
1121 | ||
1122 | spin_lock_irqsave(&master->queue_lock, flags); | |
1123 | ||
1124 | if (master->running || master->busy) { | |
1125 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1126 | return -EBUSY; | |
1127 | } | |
1128 | ||
1129 | master->running = true; | |
1130 | master->cur_msg = NULL; | |
1131 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1132 | ||
1133 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1134 | ||
1135 | return 0; | |
1136 | } | |
1137 | ||
1138 | static int spi_stop_queue(struct spi_master *master) | |
1139 | { | |
1140 | unsigned long flags; | |
1141 | unsigned limit = 500; | |
1142 | int ret = 0; | |
1143 | ||
1144 | spin_lock_irqsave(&master->queue_lock, flags); | |
1145 | ||
1146 | /* | |
1147 | * This is a bit lame, but is optimized for the common execution path. | |
1148 | * A wait_queue on the master->busy could be used, but then the common | |
1149 | * execution path (pump_messages) would be required to call wake_up or | |
1150 | * friends on every SPI message. Do this instead. | |
1151 | */ | |
1152 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
1153 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
f97b26b0 | 1154 | usleep_range(10000, 11000); |
ffbbdd21 LW |
1155 | spin_lock_irqsave(&master->queue_lock, flags); |
1156 | } | |
1157 | ||
1158 | if (!list_empty(&master->queue) || master->busy) | |
1159 | ret = -EBUSY; | |
1160 | else | |
1161 | master->running = false; | |
1162 | ||
1163 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1164 | ||
1165 | if (ret) { | |
1166 | dev_warn(&master->dev, | |
1167 | "could not stop message queue\n"); | |
1168 | return ret; | |
1169 | } | |
1170 | return ret; | |
1171 | } | |
1172 | ||
1173 | static int spi_destroy_queue(struct spi_master *master) | |
1174 | { | |
1175 | int ret; | |
1176 | ||
1177 | ret = spi_stop_queue(master); | |
1178 | ||
1179 | /* | |
1180 | * flush_kthread_worker will block until all work is done. | |
1181 | * If the reason that stop_queue timed out is that the work will never | |
1182 | * finish, then it does no good to call flush/stop thread, so | |
1183 | * return anyway. | |
1184 | */ | |
1185 | if (ret) { | |
1186 | dev_err(&master->dev, "problem destroying queue\n"); | |
1187 | return ret; | |
1188 | } | |
1189 | ||
1190 | flush_kthread_worker(&master->kworker); | |
1191 | kthread_stop(master->kworker_task); | |
1192 | ||
1193 | return 0; | |
1194 | } | |
1195 | ||
0461a414 MB |
1196 | static int __spi_queued_transfer(struct spi_device *spi, |
1197 | struct spi_message *msg, | |
1198 | bool need_pump) | |
ffbbdd21 LW |
1199 | { |
1200 | struct spi_master *master = spi->master; | |
1201 | unsigned long flags; | |
1202 | ||
1203 | spin_lock_irqsave(&master->queue_lock, flags); | |
1204 | ||
1205 | if (!master->running) { | |
1206 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1207 | return -ESHUTDOWN; | |
1208 | } | |
1209 | msg->actual_length = 0; | |
1210 | msg->status = -EINPROGRESS; | |
1211 | ||
1212 | list_add_tail(&msg->queue, &master->queue); | |
0461a414 | 1213 | if (!master->busy && need_pump) |
ffbbdd21 LW |
1214 | queue_kthread_work(&master->kworker, &master->pump_messages); |
1215 | ||
1216 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1217 | return 0; | |
1218 | } | |
1219 | ||
0461a414 MB |
1220 | /** |
1221 | * spi_queued_transfer - transfer function for queued transfers | |
1222 | * @spi: spi device which is requesting transfer | |
1223 | * @msg: spi message which is to handled is queued to driver queue | |
1224 | */ | |
1225 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
1226 | { | |
1227 | return __spi_queued_transfer(spi, msg, true); | |
1228 | } | |
1229 | ||
ffbbdd21 LW |
1230 | static int spi_master_initialize_queue(struct spi_master *master) |
1231 | { | |
1232 | int ret; | |
1233 | ||
ffbbdd21 | 1234 | master->transfer = spi_queued_transfer; |
b158935f MB |
1235 | if (!master->transfer_one_message) |
1236 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
1237 | |
1238 | /* Initialize and start queue */ | |
1239 | ret = spi_init_queue(master); | |
1240 | if (ret) { | |
1241 | dev_err(&master->dev, "problem initializing queue\n"); | |
1242 | goto err_init_queue; | |
1243 | } | |
c3676d5c | 1244 | master->queued = true; |
ffbbdd21 LW |
1245 | ret = spi_start_queue(master); |
1246 | if (ret) { | |
1247 | dev_err(&master->dev, "problem starting queue\n"); | |
1248 | goto err_start_queue; | |
1249 | } | |
1250 | ||
1251 | return 0; | |
1252 | ||
1253 | err_start_queue: | |
ffbbdd21 | 1254 | spi_destroy_queue(master); |
c3676d5c | 1255 | err_init_queue: |
ffbbdd21 LW |
1256 | return ret; |
1257 | } | |
1258 | ||
1259 | /*-------------------------------------------------------------------------*/ | |
1260 | ||
7cb94361 | 1261 | #if defined(CONFIG_OF) |
aff5e3f8 PA |
1262 | static struct spi_device * |
1263 | of_register_spi_device(struct spi_master *master, struct device_node *nc) | |
1264 | { | |
1265 | struct spi_device *spi; | |
1266 | int rc; | |
1267 | u32 value; | |
1268 | ||
1269 | /* Alloc an spi_device */ | |
1270 | spi = spi_alloc_device(master); | |
1271 | if (!spi) { | |
1272 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
1273 | nc->full_name); | |
1274 | rc = -ENOMEM; | |
1275 | goto err_out; | |
1276 | } | |
1277 | ||
1278 | /* Select device driver */ | |
1279 | rc = of_modalias_node(nc, spi->modalias, | |
1280 | sizeof(spi->modalias)); | |
1281 | if (rc < 0) { | |
1282 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
1283 | nc->full_name); | |
1284 | goto err_out; | |
1285 | } | |
1286 | ||
1287 | /* Device address */ | |
1288 | rc = of_property_read_u32(nc, "reg", &value); | |
1289 | if (rc) { | |
1290 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
1291 | nc->full_name, rc); | |
1292 | goto err_out; | |
1293 | } | |
1294 | spi->chip_select = value; | |
1295 | ||
1296 | /* Mode (clock phase/polarity/etc.) */ | |
1297 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1298 | spi->mode |= SPI_CPHA; | |
1299 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1300 | spi->mode |= SPI_CPOL; | |
1301 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1302 | spi->mode |= SPI_CS_HIGH; | |
1303 | if (of_find_property(nc, "spi-3wire", NULL)) | |
1304 | spi->mode |= SPI_3WIRE; | |
1305 | if (of_find_property(nc, "spi-lsb-first", NULL)) | |
1306 | spi->mode |= SPI_LSB_FIRST; | |
1307 | ||
1308 | /* Device DUAL/QUAD mode */ | |
1309 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { | |
1310 | switch (value) { | |
1311 | case 1: | |
1312 | break; | |
1313 | case 2: | |
1314 | spi->mode |= SPI_TX_DUAL; | |
1315 | break; | |
1316 | case 4: | |
1317 | spi->mode |= SPI_TX_QUAD; | |
1318 | break; | |
1319 | default: | |
1320 | dev_warn(&master->dev, | |
1321 | "spi-tx-bus-width %d not supported\n", | |
1322 | value); | |
1323 | break; | |
1324 | } | |
1325 | } | |
1326 | ||
1327 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { | |
1328 | switch (value) { | |
1329 | case 1: | |
1330 | break; | |
1331 | case 2: | |
1332 | spi->mode |= SPI_RX_DUAL; | |
1333 | break; | |
1334 | case 4: | |
1335 | spi->mode |= SPI_RX_QUAD; | |
1336 | break; | |
1337 | default: | |
1338 | dev_warn(&master->dev, | |
1339 | "spi-rx-bus-width %d not supported\n", | |
1340 | value); | |
1341 | break; | |
1342 | } | |
1343 | } | |
1344 | ||
1345 | /* Device speed */ | |
1346 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); | |
1347 | if (rc) { | |
1348 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1349 | nc->full_name, rc); | |
1350 | goto err_out; | |
1351 | } | |
1352 | spi->max_speed_hz = value; | |
1353 | ||
1354 | /* IRQ */ | |
1355 | spi->irq = irq_of_parse_and_map(nc, 0); | |
1356 | ||
1357 | /* Store a pointer to the node in the device structure */ | |
1358 | of_node_get(nc); | |
1359 | spi->dev.of_node = nc; | |
1360 | ||
1361 | /* Register the new device */ | |
1362 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); | |
1363 | rc = spi_add_device(spi); | |
1364 | if (rc) { | |
1365 | dev_err(&master->dev, "spi_device register error %s\n", | |
1366 | nc->full_name); | |
1367 | goto err_out; | |
1368 | } | |
1369 | ||
1370 | return spi; | |
1371 | ||
1372 | err_out: | |
1373 | spi_dev_put(spi); | |
1374 | return ERR_PTR(rc); | |
1375 | } | |
1376 | ||
d57a4282 GL |
1377 | /** |
1378 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
1379 | * @master: Pointer to spi_master device | |
1380 | * | |
1381 | * Registers an spi_device for each child node of master node which has a 'reg' | |
1382 | * property. | |
1383 | */ | |
1384 | static void of_register_spi_devices(struct spi_master *master) | |
1385 | { | |
1386 | struct spi_device *spi; | |
1387 | struct device_node *nc; | |
d57a4282 GL |
1388 | |
1389 | if (!master->dev.of_node) | |
1390 | return; | |
1391 | ||
f3b6159e | 1392 | for_each_available_child_of_node(master->dev.of_node, nc) { |
aff5e3f8 PA |
1393 | spi = of_register_spi_device(master, nc); |
1394 | if (IS_ERR(spi)) | |
1395 | dev_warn(&master->dev, "Failed to create SPI device for %s\n", | |
d57a4282 | 1396 | nc->full_name); |
d57a4282 GL |
1397 | } |
1398 | } | |
1399 | #else | |
1400 | static void of_register_spi_devices(struct spi_master *master) { } | |
1401 | #endif | |
1402 | ||
64bee4d2 MW |
1403 | #ifdef CONFIG_ACPI |
1404 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1405 | { | |
1406 | struct spi_device *spi = data; | |
1407 | ||
1408 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1409 | struct acpi_resource_spi_serialbus *sb; | |
1410 | ||
1411 | sb = &ares->data.spi_serial_bus; | |
1412 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1413 | spi->chip_select = sb->device_selection; | |
1414 | spi->max_speed_hz = sb->connection_speed; | |
1415 | ||
1416 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1417 | spi->mode |= SPI_CPHA; | |
1418 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1419 | spi->mode |= SPI_CPOL; | |
1420 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1421 | spi->mode |= SPI_CS_HIGH; | |
1422 | } | |
1423 | } else if (spi->irq < 0) { | |
1424 | struct resource r; | |
1425 | ||
1426 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1427 | spi->irq = r.start; | |
1428 | } | |
1429 | ||
1430 | /* Always tell the ACPI core to skip this resource */ | |
1431 | return 1; | |
1432 | } | |
1433 | ||
1434 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1435 | void *data, void **return_value) | |
1436 | { | |
1437 | struct spi_master *master = data; | |
1438 | struct list_head resource_list; | |
1439 | struct acpi_device *adev; | |
1440 | struct spi_device *spi; | |
1441 | int ret; | |
1442 | ||
1443 | if (acpi_bus_get_device(handle, &adev)) | |
1444 | return AE_OK; | |
1445 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1446 | return AE_OK; | |
1447 | ||
1448 | spi = spi_alloc_device(master); | |
1449 | if (!spi) { | |
1450 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1451 | dev_name(&adev->dev)); | |
1452 | return AE_NO_MEMORY; | |
1453 | } | |
1454 | ||
7b199811 | 1455 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1456 | spi->irq = -1; |
1457 | ||
1458 | INIT_LIST_HEAD(&resource_list); | |
1459 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1460 | acpi_spi_add_resource, spi); | |
1461 | acpi_dev_free_resource_list(&resource_list); | |
1462 | ||
1463 | if (ret < 0 || !spi->max_speed_hz) { | |
1464 | spi_dev_put(spi); | |
1465 | return AE_OK; | |
1466 | } | |
1467 | ||
33cf00e5 | 1468 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1469 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1470 | if (spi_add_device(spi)) { |
33cf00e5 | 1471 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1472 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
1473 | dev_name(&adev->dev)); | |
1474 | spi_dev_put(spi); | |
1475 | } | |
1476 | ||
1477 | return AE_OK; | |
1478 | } | |
1479 | ||
1480 | static void acpi_register_spi_devices(struct spi_master *master) | |
1481 | { | |
1482 | acpi_status status; | |
1483 | acpi_handle handle; | |
1484 | ||
29896178 | 1485 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1486 | if (!handle) |
1487 | return; | |
1488 | ||
1489 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1490 | acpi_spi_add_device, NULL, | |
1491 | master, NULL); | |
1492 | if (ACPI_FAILURE(status)) | |
1493 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1494 | } | |
1495 | #else | |
1496 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1497 | #endif /* CONFIG_ACPI */ | |
1498 | ||
49dce689 | 1499 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1500 | { |
1501 | struct spi_master *master; | |
1502 | ||
49dce689 | 1503 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1504 | kfree(master); |
1505 | } | |
1506 | ||
1507 | static struct class spi_master_class = { | |
1508 | .name = "spi_master", | |
1509 | .owner = THIS_MODULE, | |
49dce689 | 1510 | .dev_release = spi_master_release, |
8ae12a0d DB |
1511 | }; |
1512 | ||
1513 | ||
ffbbdd21 | 1514 | |
8ae12a0d DB |
1515 | /** |
1516 | * spi_alloc_master - allocate SPI master controller | |
1517 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1518 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1519 | * memory is in the driver_data field of the returned device, |
0c868461 | 1520 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1521 | * Context: can sleep |
8ae12a0d DB |
1522 | * |
1523 | * This call is used only by SPI master controller drivers, which are the | |
1524 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1525 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1526 | * |
1527 | * This must be called from context that can sleep. It returns the SPI | |
1528 | * master structure on success, else NULL. | |
1529 | * | |
1530 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1531 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1532 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1533 | * leak. | |
8ae12a0d | 1534 | */ |
e9d5a461 | 1535 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1536 | { |
1537 | struct spi_master *master; | |
1538 | ||
0c868461 DB |
1539 | if (!dev) |
1540 | return NULL; | |
1541 | ||
5fe5f05e | 1542 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1543 | if (!master) |
1544 | return NULL; | |
1545 | ||
49dce689 | 1546 | device_initialize(&master->dev); |
1e8a52e1 GL |
1547 | master->bus_num = -1; |
1548 | master->num_chipselect = 1; | |
49dce689 TJ |
1549 | master->dev.class = &spi_master_class; |
1550 | master->dev.parent = get_device(dev); | |
0c868461 | 1551 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1552 | |
1553 | return master; | |
1554 | } | |
1555 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1556 | ||
74317984 JCPV |
1557 | #ifdef CONFIG_OF |
1558 | static int of_spi_register_master(struct spi_master *master) | |
1559 | { | |
e80beb27 | 1560 | int nb, i, *cs; |
74317984 JCPV |
1561 | struct device_node *np = master->dev.of_node; |
1562 | ||
1563 | if (!np) | |
1564 | return 0; | |
1565 | ||
1566 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1567 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1568 | |
8ec5d84e AL |
1569 | /* Return error only for an incorrectly formed cs-gpios property */ |
1570 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1571 | return 0; |
8ec5d84e AL |
1572 | else if (nb < 0) |
1573 | return nb; | |
74317984 JCPV |
1574 | |
1575 | cs = devm_kzalloc(&master->dev, | |
1576 | sizeof(int) * master->num_chipselect, | |
1577 | GFP_KERNEL); | |
1578 | master->cs_gpios = cs; | |
1579 | ||
1580 | if (!master->cs_gpios) | |
1581 | return -ENOMEM; | |
1582 | ||
0da83bb1 | 1583 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1584 | cs[i] = -ENOENT; |
74317984 JCPV |
1585 | |
1586 | for (i = 0; i < nb; i++) | |
1587 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1588 | ||
1589 | return 0; | |
1590 | } | |
1591 | #else | |
1592 | static int of_spi_register_master(struct spi_master *master) | |
1593 | { | |
1594 | return 0; | |
1595 | } | |
1596 | #endif | |
1597 | ||
8ae12a0d DB |
1598 | /** |
1599 | * spi_register_master - register SPI master controller | |
1600 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1601 | * Context: can sleep |
8ae12a0d DB |
1602 | * |
1603 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1604 | * such as the platform bus. The final stage of probe() in that code | |
1605 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1606 | * | |
1607 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1608 | * and board-specific addressing for SPI devices combines those numbers | |
1609 | * with chip select numbers. Since SPI does not directly support dynamic | |
1610 | * device identification, boards need configuration tables telling which | |
1611 | * chip is at which address. | |
1612 | * | |
1613 | * This must be called from context that can sleep. It returns zero on | |
1614 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1615 | * After a successful return, the caller is responsible for calling |
1616 | * spi_unregister_master(). | |
8ae12a0d | 1617 | */ |
e9d5a461 | 1618 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1619 | { |
e44a45ae | 1620 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1621 | struct device *dev = master->dev.parent; |
2b9603a0 | 1622 | struct boardinfo *bi; |
8ae12a0d DB |
1623 | int status = -ENODEV; |
1624 | int dynamic = 0; | |
1625 | ||
0c868461 DB |
1626 | if (!dev) |
1627 | return -ENODEV; | |
1628 | ||
74317984 JCPV |
1629 | status = of_spi_register_master(master); |
1630 | if (status) | |
1631 | return status; | |
1632 | ||
082c8cb4 DB |
1633 | /* even if it's just one always-selected device, there must |
1634 | * be at least one chipselect | |
1635 | */ | |
1636 | if (master->num_chipselect == 0) | |
1637 | return -EINVAL; | |
1638 | ||
bb29785e GL |
1639 | if ((master->bus_num < 0) && master->dev.of_node) |
1640 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1641 | ||
8ae12a0d | 1642 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1643 | if (master->bus_num < 0) { |
082c8cb4 DB |
1644 | /* FIXME switch to an IDR based scheme, something like |
1645 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1646 | */ | |
8ae12a0d | 1647 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1648 | dynamic = 1; |
8ae12a0d DB |
1649 | } |
1650 | ||
5424d43e MB |
1651 | INIT_LIST_HEAD(&master->queue); |
1652 | spin_lock_init(&master->queue_lock); | |
cf32b71e ES |
1653 | spin_lock_init(&master->bus_lock_spinlock); |
1654 | mutex_init(&master->bus_lock_mutex); | |
1655 | master->bus_lock_flag = 0; | |
b158935f | 1656 | init_completion(&master->xfer_completion); |
6ad45a27 MB |
1657 | if (!master->max_dma_len) |
1658 | master->max_dma_len = INT_MAX; | |
cf32b71e | 1659 | |
8ae12a0d DB |
1660 | /* register the device, then userspace will see it. |
1661 | * registration fails if the bus ID is in use. | |
1662 | */ | |
35f74fca | 1663 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1664 | status = device_add(&master->dev); |
b885244e | 1665 | if (status < 0) |
8ae12a0d | 1666 | goto done; |
35f74fca | 1667 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1668 | dynamic ? " (dynamic)" : ""); |
1669 | ||
ffbbdd21 LW |
1670 | /* If we're using a queued driver, start the queue */ |
1671 | if (master->transfer) | |
1672 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1673 | else { | |
1674 | status = spi_master_initialize_queue(master); | |
1675 | if (status) { | |
e93b0724 | 1676 | device_del(&master->dev); |
ffbbdd21 LW |
1677 | goto done; |
1678 | } | |
1679 | } | |
1680 | ||
2b9603a0 FT |
1681 | mutex_lock(&board_lock); |
1682 | list_add_tail(&master->list, &spi_master_list); | |
1683 | list_for_each_entry(bi, &board_list, list) | |
1684 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1685 | mutex_unlock(&board_lock); | |
1686 | ||
64bee4d2 | 1687 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1688 | of_register_spi_devices(master); |
64bee4d2 | 1689 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1690 | done: |
1691 | return status; | |
1692 | } | |
1693 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1694 | ||
666d5b4c MB |
1695 | static void devm_spi_unregister(struct device *dev, void *res) |
1696 | { | |
1697 | spi_unregister_master(*(struct spi_master **)res); | |
1698 | } | |
1699 | ||
1700 | /** | |
1701 | * dev_spi_register_master - register managed SPI master controller | |
1702 | * @dev: device managing SPI master | |
1703 | * @master: initialized master, originally from spi_alloc_master() | |
1704 | * Context: can sleep | |
1705 | * | |
1706 | * Register a SPI device as with spi_register_master() which will | |
1707 | * automatically be unregister | |
1708 | */ | |
1709 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1710 | { | |
1711 | struct spi_master **ptr; | |
1712 | int ret; | |
1713 | ||
1714 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1715 | if (!ptr) | |
1716 | return -ENOMEM; | |
1717 | ||
1718 | ret = spi_register_master(master); | |
4b92894e | 1719 | if (!ret) { |
666d5b4c MB |
1720 | *ptr = master; |
1721 | devres_add(dev, ptr); | |
1722 | } else { | |
1723 | devres_free(ptr); | |
1724 | } | |
1725 | ||
1726 | return ret; | |
1727 | } | |
1728 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1729 | ||
34860089 | 1730 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1731 | { |
34860089 | 1732 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1733 | return 0; |
1734 | } | |
1735 | ||
1736 | /** | |
1737 | * spi_unregister_master - unregister SPI master controller | |
1738 | * @master: the master being unregistered | |
33e34dc6 | 1739 | * Context: can sleep |
8ae12a0d DB |
1740 | * |
1741 | * This call is used only by SPI master controller drivers, which are the | |
1742 | * only ones directly touching chip registers. | |
1743 | * | |
1744 | * This must be called from context that can sleep. | |
1745 | */ | |
1746 | void spi_unregister_master(struct spi_master *master) | |
1747 | { | |
89fc9a1a JG |
1748 | int dummy; |
1749 | ||
ffbbdd21 LW |
1750 | if (master->queued) { |
1751 | if (spi_destroy_queue(master)) | |
1752 | dev_err(&master->dev, "queue remove failed\n"); | |
1753 | } | |
1754 | ||
2b9603a0 FT |
1755 | mutex_lock(&board_lock); |
1756 | list_del(&master->list); | |
1757 | mutex_unlock(&board_lock); | |
1758 | ||
97dbf37d | 1759 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1760 | device_unregister(&master->dev); |
8ae12a0d DB |
1761 | } |
1762 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1763 | ||
ffbbdd21 LW |
1764 | int spi_master_suspend(struct spi_master *master) |
1765 | { | |
1766 | int ret; | |
1767 | ||
1768 | /* Basically no-ops for non-queued masters */ | |
1769 | if (!master->queued) | |
1770 | return 0; | |
1771 | ||
1772 | ret = spi_stop_queue(master); | |
1773 | if (ret) | |
1774 | dev_err(&master->dev, "queue stop failed\n"); | |
1775 | ||
1776 | return ret; | |
1777 | } | |
1778 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1779 | ||
1780 | int spi_master_resume(struct spi_master *master) | |
1781 | { | |
1782 | int ret; | |
1783 | ||
1784 | if (!master->queued) | |
1785 | return 0; | |
1786 | ||
1787 | ret = spi_start_queue(master); | |
1788 | if (ret) | |
1789 | dev_err(&master->dev, "queue restart failed\n"); | |
1790 | ||
1791 | return ret; | |
1792 | } | |
1793 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1794 | ||
9f3b795a | 1795 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1796 | { |
1797 | struct spi_master *m; | |
9f3b795a | 1798 | const u16 *bus_num = data; |
5ed2c832 DY |
1799 | |
1800 | m = container_of(dev, struct spi_master, dev); | |
1801 | return m->bus_num == *bus_num; | |
1802 | } | |
1803 | ||
8ae12a0d DB |
1804 | /** |
1805 | * spi_busnum_to_master - look up master associated with bus_num | |
1806 | * @bus_num: the master's bus number | |
33e34dc6 | 1807 | * Context: can sleep |
8ae12a0d DB |
1808 | * |
1809 | * This call may be used with devices that are registered after | |
1810 | * arch init time. It returns a refcounted pointer to the relevant | |
1811 | * spi_master (which the caller must release), or NULL if there is | |
1812 | * no such master registered. | |
1813 | */ | |
1814 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1815 | { | |
49dce689 | 1816 | struct device *dev; |
1e9a51dc | 1817 | struct spi_master *master = NULL; |
5ed2c832 | 1818 | |
695794ae | 1819 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1820 | __spi_master_match); |
1821 | if (dev) | |
1822 | master = container_of(dev, struct spi_master, dev); | |
1823 | /* reference got in class_find_device */ | |
1e9a51dc | 1824 | return master; |
8ae12a0d DB |
1825 | } |
1826 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1827 | ||
1828 | ||
1829 | /*-------------------------------------------------------------------------*/ | |
1830 | ||
7d077197 DB |
1831 | /* Core methods for SPI master protocol drivers. Some of the |
1832 | * other core methods are currently defined as inline functions. | |
1833 | */ | |
1834 | ||
1835 | /** | |
1836 | * spi_setup - setup SPI mode and clock rate | |
1837 | * @spi: the device whose settings are being modified | |
1838 | * Context: can sleep, and no requests are queued to the device | |
1839 | * | |
1840 | * SPI protocol drivers may need to update the transfer mode if the | |
1841 | * device doesn't work with its default. They may likewise need | |
1842 | * to update clock rates or word sizes from initial values. This function | |
1843 | * changes those settings, and must be called from a context that can sleep. | |
1844 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
1845 | * effect the next time the device is selected and data is transferred to | |
1846 | * or from it. When this function returns, the spi device is deselected. | |
1847 | * | |
1848 | * Note that this call will fail if the protocol driver specifies an option | |
1849 | * that the underlying controller or its driver does not support. For | |
1850 | * example, not all hardware supports wire transfers using nine bit words, | |
1851 | * LSB-first wire encoding, or active-high chipselects. | |
1852 | */ | |
1853 | int spi_setup(struct spi_device *spi) | |
1854 | { | |
83596fbe | 1855 | unsigned bad_bits, ugly_bits; |
caae070c | 1856 | int status = 0; |
7d077197 | 1857 | |
f477b7fb | 1858 | /* check mode to prevent that DUAL and QUAD set at the same time |
1859 | */ | |
1860 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
1861 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
1862 | dev_err(&spi->dev, | |
1863 | "setup: can not select dual and quad at the same time\n"); | |
1864 | return -EINVAL; | |
1865 | } | |
1866 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
1867 | */ | |
1868 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
1869 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
1870 | return -EINVAL; | |
e7db06b5 DB |
1871 | /* help drivers fail *cleanly* when they need options |
1872 | * that aren't supported with their current master | |
1873 | */ | |
1874 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
83596fbe GU |
1875 | ugly_bits = bad_bits & |
1876 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); | |
1877 | if (ugly_bits) { | |
1878 | dev_warn(&spi->dev, | |
1879 | "setup: ignoring unsupported mode bits %x\n", | |
1880 | ugly_bits); | |
1881 | spi->mode &= ~ugly_bits; | |
1882 | bad_bits &= ~ugly_bits; | |
1883 | } | |
e7db06b5 | 1884 | if (bad_bits) { |
eb288a1f | 1885 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1886 | bad_bits); |
1887 | return -EINVAL; | |
1888 | } | |
1889 | ||
7d077197 DB |
1890 | if (!spi->bits_per_word) |
1891 | spi->bits_per_word = 8; | |
1892 | ||
052eb2d4 AL |
1893 | if (!spi->max_speed_hz) |
1894 | spi->max_speed_hz = spi->master->max_speed_hz; | |
1895 | ||
caae070c LD |
1896 | if (spi->master->setup) |
1897 | status = spi->master->setup(spi); | |
7d077197 | 1898 | |
5fe5f05e | 1899 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1900 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
1901 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
1902 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
1903 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
1904 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
1905 | spi->bits_per_word, spi->max_speed_hz, | |
1906 | status); | |
1907 | ||
1908 | return status; | |
1909 | } | |
1910 | EXPORT_SYMBOL_GPL(spi_setup); | |
1911 | ||
90808738 | 1912 | static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
cf32b71e ES |
1913 | { |
1914 | struct spi_master *master = spi->master; | |
e6811d1d | 1915 | struct spi_transfer *xfer; |
6ea31293 | 1916 | int w_size; |
cf32b71e | 1917 | |
24a0013a MB |
1918 | if (list_empty(&message->transfers)) |
1919 | return -EINVAL; | |
24a0013a | 1920 | |
cf32b71e ES |
1921 | /* Half-duplex links include original MicroWire, and ones with |
1922 | * only one data pin like SPI_3WIRE (switches direction) or where | |
1923 | * either MOSI or MISO is missing. They can also be caused by | |
1924 | * software limitations. | |
1925 | */ | |
1926 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
1927 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
1928 | unsigned flags = master->flags; |
1929 | ||
1930 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
1931 | if (xfer->rx_buf && xfer->tx_buf) | |
1932 | return -EINVAL; | |
1933 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
1934 | return -EINVAL; | |
1935 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
1936 | return -EINVAL; | |
1937 | } | |
1938 | } | |
1939 | ||
e6811d1d | 1940 | /** |
059b8ffe LD |
1941 | * Set transfer bits_per_word and max speed as spi device default if |
1942 | * it is not set for this transfer. | |
f477b7fb | 1943 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1944 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1945 | */ |
1946 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1947 | message->frame_length += xfer->len; |
e6811d1d LD |
1948 | if (!xfer->bits_per_word) |
1949 | xfer->bits_per_word = spi->bits_per_word; | |
a6f87fad AL |
1950 | |
1951 | if (!xfer->speed_hz) | |
059b8ffe | 1952 | xfer->speed_hz = spi->max_speed_hz; |
a6f87fad AL |
1953 | |
1954 | if (master->max_speed_hz && | |
1955 | xfer->speed_hz > master->max_speed_hz) | |
1956 | xfer->speed_hz = master->max_speed_hz; | |
56ede94a | 1957 | |
543bb255 SW |
1958 | if (master->bits_per_word_mask) { |
1959 | /* Only 32 bits fit in the mask */ | |
1960 | if (xfer->bits_per_word > 32) | |
1961 | return -EINVAL; | |
1962 | if (!(master->bits_per_word_mask & | |
1963 | BIT(xfer->bits_per_word - 1))) | |
1964 | return -EINVAL; | |
1965 | } | |
a2fd4f9f | 1966 | |
4d94bd21 II |
1967 | /* |
1968 | * SPI transfer length should be multiple of SPI word size | |
1969 | * where SPI word size should be power-of-two multiple | |
1970 | */ | |
1971 | if (xfer->bits_per_word <= 8) | |
1972 | w_size = 1; | |
1973 | else if (xfer->bits_per_word <= 16) | |
1974 | w_size = 2; | |
1975 | else | |
1976 | w_size = 4; | |
1977 | ||
4d94bd21 | 1978 | /* No partial transfers accepted */ |
6ea31293 | 1979 | if (xfer->len % w_size) |
4d94bd21 II |
1980 | return -EINVAL; |
1981 | ||
a2fd4f9f MB |
1982 | if (xfer->speed_hz && master->min_speed_hz && |
1983 | xfer->speed_hz < master->min_speed_hz) | |
1984 | return -EINVAL; | |
f477b7fb | 1985 | |
1986 | if (xfer->tx_buf && !xfer->tx_nbits) | |
1987 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
1988 | if (xfer->rx_buf && !xfer->rx_nbits) | |
1989 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
1990 | /* check transfer tx/rx_nbits: | |
1afd9989 GU |
1991 | * 1. check the value matches one of single, dual and quad |
1992 | * 2. check tx/rx_nbits match the mode in spi_device | |
f477b7fb | 1993 | */ |
db90a441 SP |
1994 | if (xfer->tx_buf) { |
1995 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
1996 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
1997 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
1998 | return -EINVAL; | |
1999 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
2000 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
2001 | return -EINVAL; | |
2002 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
2003 | !(spi->mode & SPI_TX_QUAD)) | |
2004 | return -EINVAL; | |
db90a441 | 2005 | } |
f477b7fb | 2006 | /* check transfer rx_nbits */ |
db90a441 SP |
2007 | if (xfer->rx_buf) { |
2008 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
2009 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
2010 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
2011 | return -EINVAL; | |
2012 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
2013 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
2014 | return -EINVAL; | |
2015 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
2016 | !(spi->mode & SPI_RX_QUAD)) | |
2017 | return -EINVAL; | |
db90a441 | 2018 | } |
e6811d1d LD |
2019 | } |
2020 | ||
cf32b71e | 2021 | message->status = -EINPROGRESS; |
90808738 MB |
2022 | |
2023 | return 0; | |
2024 | } | |
2025 | ||
2026 | static int __spi_async(struct spi_device *spi, struct spi_message *message) | |
2027 | { | |
2028 | struct spi_master *master = spi->master; | |
2029 | ||
2030 | message->spi = spi; | |
2031 | ||
2032 | trace_spi_message_submit(message); | |
2033 | ||
cf32b71e ES |
2034 | return master->transfer(spi, message); |
2035 | } | |
2036 | ||
568d0697 DB |
2037 | /** |
2038 | * spi_async - asynchronous SPI transfer | |
2039 | * @spi: device with which data will be exchanged | |
2040 | * @message: describes the data transfers, including completion callback | |
2041 | * Context: any (irqs may be blocked, etc) | |
2042 | * | |
2043 | * This call may be used in_irq and other contexts which can't sleep, | |
2044 | * as well as from task contexts which can sleep. | |
2045 | * | |
2046 | * The completion callback is invoked in a context which can't sleep. | |
2047 | * Before that invocation, the value of message->status is undefined. | |
2048 | * When the callback is issued, message->status holds either zero (to | |
2049 | * indicate complete success) or a negative error code. After that | |
2050 | * callback returns, the driver which issued the transfer request may | |
2051 | * deallocate the associated memory; it's no longer in use by any SPI | |
2052 | * core or controller driver code. | |
2053 | * | |
2054 | * Note that although all messages to a spi_device are handled in | |
2055 | * FIFO order, messages may go to different devices in other orders. | |
2056 | * Some device might be higher priority, or have various "hard" access | |
2057 | * time requirements, for example. | |
2058 | * | |
2059 | * On detection of any fault during the transfer, processing of | |
2060 | * the entire message is aborted, and the device is deselected. | |
2061 | * Until returning from the associated message completion callback, | |
2062 | * no other spi_message queued to that device will be processed. | |
2063 | * (This rule applies equally to all the synchronous transfer calls, | |
2064 | * which are wrappers around this core asynchronous primitive.) | |
2065 | */ | |
2066 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
2067 | { | |
2068 | struct spi_master *master = spi->master; | |
cf32b71e ES |
2069 | int ret; |
2070 | unsigned long flags; | |
568d0697 | 2071 | |
90808738 MB |
2072 | ret = __spi_validate(spi, message); |
2073 | if (ret != 0) | |
2074 | return ret; | |
2075 | ||
cf32b71e | 2076 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 2077 | |
cf32b71e ES |
2078 | if (master->bus_lock_flag) |
2079 | ret = -EBUSY; | |
2080 | else | |
2081 | ret = __spi_async(spi, message); | |
568d0697 | 2082 | |
cf32b71e ES |
2083 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
2084 | ||
2085 | return ret; | |
568d0697 DB |
2086 | } |
2087 | EXPORT_SYMBOL_GPL(spi_async); | |
2088 | ||
cf32b71e ES |
2089 | /** |
2090 | * spi_async_locked - version of spi_async with exclusive bus usage | |
2091 | * @spi: device with which data will be exchanged | |
2092 | * @message: describes the data transfers, including completion callback | |
2093 | * Context: any (irqs may be blocked, etc) | |
2094 | * | |
2095 | * This call may be used in_irq and other contexts which can't sleep, | |
2096 | * as well as from task contexts which can sleep. | |
2097 | * | |
2098 | * The completion callback is invoked in a context which can't sleep. | |
2099 | * Before that invocation, the value of message->status is undefined. | |
2100 | * When the callback is issued, message->status holds either zero (to | |
2101 | * indicate complete success) or a negative error code. After that | |
2102 | * callback returns, the driver which issued the transfer request may | |
2103 | * deallocate the associated memory; it's no longer in use by any SPI | |
2104 | * core or controller driver code. | |
2105 | * | |
2106 | * Note that although all messages to a spi_device are handled in | |
2107 | * FIFO order, messages may go to different devices in other orders. | |
2108 | * Some device might be higher priority, or have various "hard" access | |
2109 | * time requirements, for example. | |
2110 | * | |
2111 | * On detection of any fault during the transfer, processing of | |
2112 | * the entire message is aborted, and the device is deselected. | |
2113 | * Until returning from the associated message completion callback, | |
2114 | * no other spi_message queued to that device will be processed. | |
2115 | * (This rule applies equally to all the synchronous transfer calls, | |
2116 | * which are wrappers around this core asynchronous primitive.) | |
2117 | */ | |
2118 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
2119 | { | |
2120 | struct spi_master *master = spi->master; | |
2121 | int ret; | |
2122 | unsigned long flags; | |
2123 | ||
90808738 MB |
2124 | ret = __spi_validate(spi, message); |
2125 | if (ret != 0) | |
2126 | return ret; | |
2127 | ||
cf32b71e ES |
2128 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
2129 | ||
2130 | ret = __spi_async(spi, message); | |
2131 | ||
2132 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2133 | ||
2134 | return ret; | |
2135 | ||
2136 | } | |
2137 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
2138 | ||
7d077197 DB |
2139 | |
2140 | /*-------------------------------------------------------------------------*/ | |
2141 | ||
2142 | /* Utility methods for SPI master protocol drivers, layered on | |
2143 | * top of the core. Some other utility methods are defined as | |
2144 | * inline functions. | |
2145 | */ | |
2146 | ||
5d870c8e AM |
2147 | static void spi_complete(void *arg) |
2148 | { | |
2149 | complete(arg); | |
2150 | } | |
2151 | ||
cf32b71e ES |
2152 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
2153 | int bus_locked) | |
2154 | { | |
2155 | DECLARE_COMPLETION_ONSTACK(done); | |
2156 | int status; | |
2157 | struct spi_master *master = spi->master; | |
0461a414 MB |
2158 | unsigned long flags; |
2159 | ||
2160 | status = __spi_validate(spi, message); | |
2161 | if (status != 0) | |
2162 | return status; | |
cf32b71e ES |
2163 | |
2164 | message->complete = spi_complete; | |
2165 | message->context = &done; | |
0461a414 | 2166 | message->spi = spi; |
cf32b71e ES |
2167 | |
2168 | if (!bus_locked) | |
2169 | mutex_lock(&master->bus_lock_mutex); | |
2170 | ||
0461a414 MB |
2171 | /* If we're not using the legacy transfer method then we will |
2172 | * try to transfer in the calling context so special case. | |
2173 | * This code would be less tricky if we could remove the | |
2174 | * support for driver implemented message queues. | |
2175 | */ | |
2176 | if (master->transfer == spi_queued_transfer) { | |
2177 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2178 | ||
2179 | trace_spi_message_submit(message); | |
2180 | ||
2181 | status = __spi_queued_transfer(spi, message, false); | |
2182 | ||
2183 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2184 | } else { | |
2185 | status = spi_async_locked(spi, message); | |
2186 | } | |
cf32b71e ES |
2187 | |
2188 | if (!bus_locked) | |
2189 | mutex_unlock(&master->bus_lock_mutex); | |
2190 | ||
2191 | if (status == 0) { | |
0461a414 MB |
2192 | /* Push out the messages in the calling context if we |
2193 | * can. | |
2194 | */ | |
2195 | if (master->transfer == spi_queued_transfer) | |
fc9e0f71 | 2196 | __spi_pump_messages(master, false); |
0461a414 | 2197 | |
cf32b71e ES |
2198 | wait_for_completion(&done); |
2199 | status = message->status; | |
2200 | } | |
2201 | message->context = NULL; | |
2202 | return status; | |
2203 | } | |
2204 | ||
8ae12a0d DB |
2205 | /** |
2206 | * spi_sync - blocking/synchronous SPI data transfers | |
2207 | * @spi: device with which data will be exchanged | |
2208 | * @message: describes the data transfers | |
33e34dc6 | 2209 | * Context: can sleep |
8ae12a0d DB |
2210 | * |
2211 | * This call may only be used from a context that may sleep. The sleep | |
2212 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2213 | * drivers may DMA directly into and out of the message buffers. | |
2214 | * | |
2215 | * Note that the SPI device's chip select is active during the message, | |
2216 | * and then is normally disabled between messages. Drivers for some | |
2217 | * frequently-used devices may want to minimize costs of selecting a chip, | |
2218 | * by leaving it selected in anticipation that the next message will go | |
2219 | * to the same chip. (That may increase power usage.) | |
2220 | * | |
0c868461 DB |
2221 | * Also, the caller is guaranteeing that the memory associated with the |
2222 | * message will not be freed before this call returns. | |
2223 | * | |
9b938b74 | 2224 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
2225 | */ |
2226 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
2227 | { | |
cf32b71e | 2228 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
2229 | } |
2230 | EXPORT_SYMBOL_GPL(spi_sync); | |
2231 | ||
cf32b71e ES |
2232 | /** |
2233 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
2234 | * @spi: device with which data will be exchanged | |
2235 | * @message: describes the data transfers | |
2236 | * Context: can sleep | |
2237 | * | |
2238 | * This call may only be used from a context that may sleep. The sleep | |
2239 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2240 | * drivers may DMA directly into and out of the message buffers. | |
2241 | * | |
2242 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 2243 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
2244 | * be released by a spi_bus_unlock call when the exclusive access is over. |
2245 | * | |
2246 | * It returns zero on success, else a negative error code. | |
2247 | */ | |
2248 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
2249 | { | |
2250 | return __spi_sync(spi, message, 1); | |
2251 | } | |
2252 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
2253 | ||
2254 | /** | |
2255 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
2256 | * @master: SPI bus master that should be locked for exclusive bus access | |
2257 | * Context: can sleep | |
2258 | * | |
2259 | * This call may only be used from a context that may sleep. The sleep | |
2260 | * is non-interruptible, and has no timeout. | |
2261 | * | |
2262 | * This call should be used by drivers that require exclusive access to the | |
2263 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
2264 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
2265 | * and spi_async_locked calls when the SPI bus lock is held. | |
2266 | * | |
2267 | * It returns zero on success, else a negative error code. | |
2268 | */ | |
2269 | int spi_bus_lock(struct spi_master *master) | |
2270 | { | |
2271 | unsigned long flags; | |
2272 | ||
2273 | mutex_lock(&master->bus_lock_mutex); | |
2274 | ||
2275 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2276 | master->bus_lock_flag = 1; | |
2277 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2278 | ||
2279 | /* mutex remains locked until spi_bus_unlock is called */ | |
2280 | ||
2281 | return 0; | |
2282 | } | |
2283 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
2284 | ||
2285 | /** | |
2286 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
2287 | * @master: SPI bus master that was locked for exclusive bus access | |
2288 | * Context: can sleep | |
2289 | * | |
2290 | * This call may only be used from a context that may sleep. The sleep | |
2291 | * is non-interruptible, and has no timeout. | |
2292 | * | |
2293 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
2294 | * call. | |
2295 | * | |
2296 | * It returns zero on success, else a negative error code. | |
2297 | */ | |
2298 | int spi_bus_unlock(struct spi_master *master) | |
2299 | { | |
2300 | master->bus_lock_flag = 0; | |
2301 | ||
2302 | mutex_unlock(&master->bus_lock_mutex); | |
2303 | ||
2304 | return 0; | |
2305 | } | |
2306 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
2307 | ||
a9948b61 | 2308 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 2309 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
2310 | |
2311 | static u8 *buf; | |
2312 | ||
2313 | /** | |
2314 | * spi_write_then_read - SPI synchronous write followed by read | |
2315 | * @spi: device with which data will be exchanged | |
2316 | * @txbuf: data to be written (need not be dma-safe) | |
2317 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
2318 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
2319 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 2320 | * Context: can sleep |
8ae12a0d DB |
2321 | * |
2322 | * This performs a half duplex MicroWire style transaction with the | |
2323 | * device, sending txbuf and then reading rxbuf. The return value | |
2324 | * is zero for success, else a negative errno status code. | |
b885244e | 2325 | * This call may only be used from a context that may sleep. |
8ae12a0d | 2326 | * |
0c868461 | 2327 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
2328 | * portable code should never use this for more than 32 bytes. |
2329 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 2330 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
2331 | */ |
2332 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
2333 | const void *txbuf, unsigned n_tx, |
2334 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 2335 | { |
068f4070 | 2336 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
2337 | |
2338 | int status; | |
2339 | struct spi_message message; | |
bdff549e | 2340 | struct spi_transfer x[2]; |
8ae12a0d DB |
2341 | u8 *local_buf; |
2342 | ||
b3a223ee MB |
2343 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
2344 | * copying here, (as a pure convenience thing), but we can | |
2345 | * keep heap costs out of the hot path unless someone else is | |
2346 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 2347 | */ |
b3a223ee | 2348 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
2349 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
2350 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
2351 | if (!local_buf) |
2352 | return -ENOMEM; | |
2353 | } else { | |
2354 | local_buf = buf; | |
2355 | } | |
8ae12a0d | 2356 | |
8275c642 | 2357 | spi_message_init(&message); |
5fe5f05e | 2358 | memset(x, 0, sizeof(x)); |
bdff549e DB |
2359 | if (n_tx) { |
2360 | x[0].len = n_tx; | |
2361 | spi_message_add_tail(&x[0], &message); | |
2362 | } | |
2363 | if (n_rx) { | |
2364 | x[1].len = n_rx; | |
2365 | spi_message_add_tail(&x[1], &message); | |
2366 | } | |
8275c642 | 2367 | |
8ae12a0d | 2368 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2369 | x[0].tx_buf = local_buf; |
2370 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2371 | |
2372 | /* do the i/o */ | |
8ae12a0d | 2373 | status = spi_sync(spi, &message); |
9b938b74 | 2374 | if (status == 0) |
bdff549e | 2375 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2376 | |
bdff549e | 2377 | if (x[0].tx_buf == buf) |
068f4070 | 2378 | mutex_unlock(&lock); |
8ae12a0d DB |
2379 | else |
2380 | kfree(local_buf); | |
2381 | ||
2382 | return status; | |
2383 | } | |
2384 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2385 | ||
2386 | /*-------------------------------------------------------------------------*/ | |
2387 | ||
ce79d54a PA |
2388 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
2389 | static int __spi_of_device_match(struct device *dev, void *data) | |
2390 | { | |
2391 | return dev->of_node == data; | |
2392 | } | |
2393 | ||
2394 | /* must call put_device() when done with returned spi_device device */ | |
2395 | static struct spi_device *of_find_spi_device_by_node(struct device_node *node) | |
2396 | { | |
2397 | struct device *dev = bus_find_device(&spi_bus_type, NULL, node, | |
2398 | __spi_of_device_match); | |
2399 | return dev ? to_spi_device(dev) : NULL; | |
2400 | } | |
2401 | ||
2402 | static int __spi_of_master_match(struct device *dev, const void *data) | |
2403 | { | |
2404 | return dev->of_node == data; | |
2405 | } | |
2406 | ||
2407 | /* the spi masters are not using spi_bus, so we find it with another way */ | |
2408 | static struct spi_master *of_find_spi_master_by_node(struct device_node *node) | |
2409 | { | |
2410 | struct device *dev; | |
2411 | ||
2412 | dev = class_find_device(&spi_master_class, NULL, node, | |
2413 | __spi_of_master_match); | |
2414 | if (!dev) | |
2415 | return NULL; | |
2416 | ||
2417 | /* reference got in class_find_device */ | |
2418 | return container_of(dev, struct spi_master, dev); | |
2419 | } | |
2420 | ||
2421 | static int of_spi_notify(struct notifier_block *nb, unsigned long action, | |
2422 | void *arg) | |
2423 | { | |
2424 | struct of_reconfig_data *rd = arg; | |
2425 | struct spi_master *master; | |
2426 | struct spi_device *spi; | |
2427 | ||
2428 | switch (of_reconfig_get_state_change(action, arg)) { | |
2429 | case OF_RECONFIG_CHANGE_ADD: | |
2430 | master = of_find_spi_master_by_node(rd->dn->parent); | |
2431 | if (master == NULL) | |
2432 | return NOTIFY_OK; /* not for us */ | |
2433 | ||
2434 | spi = of_register_spi_device(master, rd->dn); | |
2435 | put_device(&master->dev); | |
2436 | ||
2437 | if (IS_ERR(spi)) { | |
2438 | pr_err("%s: failed to create for '%s'\n", | |
2439 | __func__, rd->dn->full_name); | |
2440 | return notifier_from_errno(PTR_ERR(spi)); | |
2441 | } | |
2442 | break; | |
2443 | ||
2444 | case OF_RECONFIG_CHANGE_REMOVE: | |
2445 | /* find our device by node */ | |
2446 | spi = of_find_spi_device_by_node(rd->dn); | |
2447 | if (spi == NULL) | |
2448 | return NOTIFY_OK; /* no? not meant for us */ | |
2449 | ||
2450 | /* unregister takes one ref away */ | |
2451 | spi_unregister_device(spi); | |
2452 | ||
2453 | /* and put the reference of the find */ | |
2454 | put_device(&spi->dev); | |
2455 | break; | |
2456 | } | |
2457 | ||
2458 | return NOTIFY_OK; | |
2459 | } | |
2460 | ||
2461 | static struct notifier_block spi_of_notifier = { | |
2462 | .notifier_call = of_spi_notify, | |
2463 | }; | |
2464 | #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2465 | extern struct notifier_block spi_of_notifier; | |
2466 | #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2467 | ||
8ae12a0d DB |
2468 | static int __init spi_init(void) |
2469 | { | |
b885244e DB |
2470 | int status; |
2471 | ||
e94b1766 | 2472 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2473 | if (!buf) { |
2474 | status = -ENOMEM; | |
2475 | goto err0; | |
2476 | } | |
2477 | ||
2478 | status = bus_register(&spi_bus_type); | |
2479 | if (status < 0) | |
2480 | goto err1; | |
8ae12a0d | 2481 | |
b885244e DB |
2482 | status = class_register(&spi_master_class); |
2483 | if (status < 0) | |
2484 | goto err2; | |
ce79d54a | 2485 | |
5267720e | 2486 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
ce79d54a PA |
2487 | WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); |
2488 | ||
8ae12a0d | 2489 | return 0; |
b885244e DB |
2490 | |
2491 | err2: | |
2492 | bus_unregister(&spi_bus_type); | |
2493 | err1: | |
2494 | kfree(buf); | |
2495 | buf = NULL; | |
2496 | err0: | |
2497 | return status; | |
8ae12a0d | 2498 | } |
b885244e | 2499 | |
8ae12a0d DB |
2500 | /* board_info is normally registered in arch_initcall(), |
2501 | * but even essential drivers wait till later | |
b885244e DB |
2502 | * |
2503 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2504 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2505 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2506 | */ |
673c0c00 | 2507 | postcore_initcall(spi_init); |
8ae12a0d | 2508 |