Commit | Line | Data |
---|---|---|
8ae12a0d | 1 | /* |
ca632f55 | 2 | * SPI init/core code |
8ae12a0d DB |
3 | * |
4 | * Copyright (C) 2005 David Brownell | |
d57a4282 | 5 | * Copyright (C) 2008 Secret Lab Technologies Ltd. |
8ae12a0d DB |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
8ae12a0d | 22 | #include <linux/kernel.h> |
d57a4282 | 23 | #include <linux/kmod.h> |
8ae12a0d DB |
24 | #include <linux/device.h> |
25 | #include <linux/init.h> | |
26 | #include <linux/cache.h> | |
99adef31 MB |
27 | #include <linux/dma-mapping.h> |
28 | #include <linux/dmaengine.h> | |
94040828 | 29 | #include <linux/mutex.h> |
2b7a32f7 | 30 | #include <linux/of_device.h> |
d57a4282 | 31 | #include <linux/of_irq.h> |
86be408b | 32 | #include <linux/clk/clk-conf.h> |
5a0e3ad6 | 33 | #include <linux/slab.h> |
e0626e38 | 34 | #include <linux/mod_devicetable.h> |
8ae12a0d | 35 | #include <linux/spi/spi.h> |
74317984 | 36 | #include <linux/of_gpio.h> |
3ae22e8c | 37 | #include <linux/pm_runtime.h> |
025ed130 | 38 | #include <linux/export.h> |
8bd75c77 | 39 | #include <linux/sched/rt.h> |
ffbbdd21 LW |
40 | #include <linux/delay.h> |
41 | #include <linux/kthread.h> | |
64bee4d2 MW |
42 | #include <linux/ioport.h> |
43 | #include <linux/acpi.h> | |
8ae12a0d | 44 | |
56ec1978 MB |
45 | #define CREATE_TRACE_POINTS |
46 | #include <trace/events/spi.h> | |
47 | ||
8ae12a0d DB |
48 | static void spidev_release(struct device *dev) |
49 | { | |
0ffa0285 | 50 | struct spi_device *spi = to_spi_device(dev); |
8ae12a0d DB |
51 | |
52 | /* spi masters may cleanup for released devices */ | |
53 | if (spi->master->cleanup) | |
54 | spi->master->cleanup(spi); | |
55 | ||
0c868461 | 56 | spi_master_put(spi->master); |
07a389fe | 57 | kfree(spi); |
8ae12a0d DB |
58 | } |
59 | ||
60 | static ssize_t | |
61 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) | |
62 | { | |
63 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
64 | int len; |
65 | ||
66 | len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); | |
67 | if (len != -ENODEV) | |
68 | return len; | |
8ae12a0d | 69 | |
d8e328b3 | 70 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d | 71 | } |
aa7da564 | 72 | static DEVICE_ATTR_RO(modalias); |
8ae12a0d | 73 | |
aa7da564 GKH |
74 | static struct attribute *spi_dev_attrs[] = { |
75 | &dev_attr_modalias.attr, | |
76 | NULL, | |
8ae12a0d | 77 | }; |
aa7da564 | 78 | ATTRIBUTE_GROUPS(spi_dev); |
8ae12a0d DB |
79 | |
80 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, | |
81 | * and the sysfs version makes coldplug work too. | |
82 | */ | |
83 | ||
75368bf6 AV |
84 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
85 | const struct spi_device *sdev) | |
86 | { | |
87 | while (id->name[0]) { | |
88 | if (!strcmp(sdev->modalias, id->name)) | |
89 | return id; | |
90 | id++; | |
91 | } | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) | |
96 | { | |
97 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); | |
98 | ||
99 | return spi_match_id(sdrv->id_table, sdev); | |
100 | } | |
101 | EXPORT_SYMBOL_GPL(spi_get_device_id); | |
102 | ||
8ae12a0d DB |
103 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
104 | { | |
105 | const struct spi_device *spi = to_spi_device(dev); | |
75368bf6 AV |
106 | const struct spi_driver *sdrv = to_spi_driver(drv); |
107 | ||
2b7a32f7 SA |
108 | /* Attempt an OF style match */ |
109 | if (of_driver_match_device(dev, drv)) | |
110 | return 1; | |
111 | ||
64bee4d2 MW |
112 | /* Then try ACPI */ |
113 | if (acpi_driver_match_device(dev, drv)) | |
114 | return 1; | |
115 | ||
75368bf6 AV |
116 | if (sdrv->id_table) |
117 | return !!spi_match_id(sdrv->id_table, spi); | |
8ae12a0d | 118 | |
35f74fca | 119 | return strcmp(spi->modalias, drv->name) == 0; |
8ae12a0d DB |
120 | } |
121 | ||
7eff2e7a | 122 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
8ae12a0d DB |
123 | { |
124 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
125 | int rc; |
126 | ||
127 | rc = acpi_device_uevent_modalias(dev, env); | |
128 | if (rc != -ENODEV) | |
129 | return rc; | |
8ae12a0d | 130 | |
e0626e38 | 131 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d DB |
132 | return 0; |
133 | } | |
134 | ||
3ae22e8c MB |
135 | #ifdef CONFIG_PM_SLEEP |
136 | static int spi_legacy_suspend(struct device *dev, pm_message_t message) | |
8ae12a0d | 137 | { |
3c72426f | 138 | int value = 0; |
b885244e | 139 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 140 | |
8ae12a0d | 141 | /* suspend will stop irqs and dma; no more i/o */ |
3c72426f DB |
142 | if (drv) { |
143 | if (drv->suspend) | |
144 | value = drv->suspend(to_spi_device(dev), message); | |
145 | else | |
146 | dev_dbg(dev, "... can't suspend\n"); | |
147 | } | |
8ae12a0d DB |
148 | return value; |
149 | } | |
150 | ||
3ae22e8c | 151 | static int spi_legacy_resume(struct device *dev) |
8ae12a0d | 152 | { |
3c72426f | 153 | int value = 0; |
b885244e | 154 | struct spi_driver *drv = to_spi_driver(dev->driver); |
8ae12a0d | 155 | |
8ae12a0d | 156 | /* resume may restart the i/o queue */ |
3c72426f DB |
157 | if (drv) { |
158 | if (drv->resume) | |
159 | value = drv->resume(to_spi_device(dev)); | |
160 | else | |
161 | dev_dbg(dev, "... can't resume\n"); | |
162 | } | |
8ae12a0d DB |
163 | return value; |
164 | } | |
165 | ||
3ae22e8c MB |
166 | static int spi_pm_suspend(struct device *dev) |
167 | { | |
168 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
169 | ||
170 | if (pm) | |
171 | return pm_generic_suspend(dev); | |
172 | else | |
173 | return spi_legacy_suspend(dev, PMSG_SUSPEND); | |
174 | } | |
175 | ||
176 | static int spi_pm_resume(struct device *dev) | |
177 | { | |
178 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
179 | ||
180 | if (pm) | |
181 | return pm_generic_resume(dev); | |
182 | else | |
183 | return spi_legacy_resume(dev); | |
184 | } | |
185 | ||
186 | static int spi_pm_freeze(struct device *dev) | |
187 | { | |
188 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
189 | ||
190 | if (pm) | |
191 | return pm_generic_freeze(dev); | |
192 | else | |
193 | return spi_legacy_suspend(dev, PMSG_FREEZE); | |
194 | } | |
195 | ||
196 | static int spi_pm_thaw(struct device *dev) | |
197 | { | |
198 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
199 | ||
200 | if (pm) | |
201 | return pm_generic_thaw(dev); | |
202 | else | |
203 | return spi_legacy_resume(dev); | |
204 | } | |
205 | ||
206 | static int spi_pm_poweroff(struct device *dev) | |
207 | { | |
208 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
209 | ||
210 | if (pm) | |
211 | return pm_generic_poweroff(dev); | |
212 | else | |
213 | return spi_legacy_suspend(dev, PMSG_HIBERNATE); | |
214 | } | |
215 | ||
216 | static int spi_pm_restore(struct device *dev) | |
217 | { | |
218 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
219 | ||
220 | if (pm) | |
221 | return pm_generic_restore(dev); | |
222 | else | |
223 | return spi_legacy_resume(dev); | |
224 | } | |
8ae12a0d | 225 | #else |
3ae22e8c MB |
226 | #define spi_pm_suspend NULL |
227 | #define spi_pm_resume NULL | |
228 | #define spi_pm_freeze NULL | |
229 | #define spi_pm_thaw NULL | |
230 | #define spi_pm_poweroff NULL | |
231 | #define spi_pm_restore NULL | |
8ae12a0d DB |
232 | #endif |
233 | ||
3ae22e8c MB |
234 | static const struct dev_pm_ops spi_pm = { |
235 | .suspend = spi_pm_suspend, | |
236 | .resume = spi_pm_resume, | |
237 | .freeze = spi_pm_freeze, | |
238 | .thaw = spi_pm_thaw, | |
239 | .poweroff = spi_pm_poweroff, | |
240 | .restore = spi_pm_restore, | |
241 | SET_RUNTIME_PM_OPS( | |
242 | pm_generic_runtime_suspend, | |
243 | pm_generic_runtime_resume, | |
45f0a85c | 244 | NULL |
3ae22e8c MB |
245 | ) |
246 | }; | |
247 | ||
8ae12a0d DB |
248 | struct bus_type spi_bus_type = { |
249 | .name = "spi", | |
aa7da564 | 250 | .dev_groups = spi_dev_groups, |
8ae12a0d DB |
251 | .match = spi_match_device, |
252 | .uevent = spi_uevent, | |
3ae22e8c | 253 | .pm = &spi_pm, |
8ae12a0d DB |
254 | }; |
255 | EXPORT_SYMBOL_GPL(spi_bus_type); | |
256 | ||
b885244e DB |
257 | |
258 | static int spi_drv_probe(struct device *dev) | |
259 | { | |
260 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
261 | int ret; |
262 | ||
86be408b SN |
263 | ret = of_clk_set_defaults(dev->of_node, false); |
264 | if (ret) | |
265 | return ret; | |
266 | ||
aec35f4e JD |
267 | acpi_dev_pm_attach(dev, true); |
268 | ret = sdrv->probe(to_spi_device(dev)); | |
33cf00e5 | 269 | if (ret) |
aec35f4e | 270 | acpi_dev_pm_detach(dev, true); |
b885244e | 271 | |
33cf00e5 | 272 | return ret; |
b885244e DB |
273 | } |
274 | ||
275 | static int spi_drv_remove(struct device *dev) | |
276 | { | |
277 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
278 | int ret; |
279 | ||
aec35f4e JD |
280 | ret = sdrv->remove(to_spi_device(dev)); |
281 | acpi_dev_pm_detach(dev, true); | |
b885244e | 282 | |
33cf00e5 | 283 | return ret; |
b885244e DB |
284 | } |
285 | ||
286 | static void spi_drv_shutdown(struct device *dev) | |
287 | { | |
288 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
289 | ||
290 | sdrv->shutdown(to_spi_device(dev)); | |
291 | } | |
292 | ||
33e34dc6 DB |
293 | /** |
294 | * spi_register_driver - register a SPI driver | |
295 | * @sdrv: the driver to register | |
296 | * Context: can sleep | |
297 | */ | |
b885244e DB |
298 | int spi_register_driver(struct spi_driver *sdrv) |
299 | { | |
300 | sdrv->driver.bus = &spi_bus_type; | |
301 | if (sdrv->probe) | |
302 | sdrv->driver.probe = spi_drv_probe; | |
303 | if (sdrv->remove) | |
304 | sdrv->driver.remove = spi_drv_remove; | |
305 | if (sdrv->shutdown) | |
306 | sdrv->driver.shutdown = spi_drv_shutdown; | |
307 | return driver_register(&sdrv->driver); | |
308 | } | |
309 | EXPORT_SYMBOL_GPL(spi_register_driver); | |
310 | ||
8ae12a0d DB |
311 | /*-------------------------------------------------------------------------*/ |
312 | ||
313 | /* SPI devices should normally not be created by SPI device drivers; that | |
314 | * would make them board-specific. Similarly with SPI master drivers. | |
315 | * Device registration normally goes into like arch/.../mach.../board-YYY.c | |
316 | * with other readonly (flashable) information about mainboard devices. | |
317 | */ | |
318 | ||
319 | struct boardinfo { | |
320 | struct list_head list; | |
2b9603a0 | 321 | struct spi_board_info board_info; |
8ae12a0d DB |
322 | }; |
323 | ||
324 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
325 | static LIST_HEAD(spi_master_list); |
326 | ||
327 | /* | |
328 | * Used to protect add/del opertion for board_info list and | |
329 | * spi_master list, and their matching process | |
330 | */ | |
94040828 | 331 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 332 | |
dc87c98e GL |
333 | /** |
334 | * spi_alloc_device - Allocate a new SPI device | |
335 | * @master: Controller to which device is connected | |
336 | * Context: can sleep | |
337 | * | |
338 | * Allows a driver to allocate and initialize a spi_device without | |
339 | * registering it immediately. This allows a driver to directly | |
340 | * fill the spi_device with device parameters before calling | |
341 | * spi_add_device() on it. | |
342 | * | |
343 | * Caller is responsible to call spi_add_device() on the returned | |
344 | * spi_device structure to add it to the SPI master. If the caller | |
345 | * needs to discard the spi_device without adding it, then it should | |
346 | * call spi_dev_put() on it. | |
347 | * | |
348 | * Returns a pointer to the new device, or NULL. | |
349 | */ | |
350 | struct spi_device *spi_alloc_device(struct spi_master *master) | |
351 | { | |
352 | struct spi_device *spi; | |
dc87c98e GL |
353 | |
354 | if (!spi_master_get(master)) | |
355 | return NULL; | |
356 | ||
5fe5f05e | 357 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e | 358 | if (!spi) { |
dc87c98e GL |
359 | spi_master_put(master); |
360 | return NULL; | |
361 | } | |
362 | ||
363 | spi->master = master; | |
178db7d3 | 364 | spi->dev.parent = &master->dev; |
dc87c98e GL |
365 | spi->dev.bus = &spi_bus_type; |
366 | spi->dev.release = spidev_release; | |
446411e1 | 367 | spi->cs_gpio = -ENOENT; |
dc87c98e GL |
368 | device_initialize(&spi->dev); |
369 | return spi; | |
370 | } | |
371 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
372 | ||
e13ac47b JN |
373 | static void spi_dev_set_name(struct spi_device *spi) |
374 | { | |
375 | struct acpi_device *adev = ACPI_COMPANION(&spi->dev); | |
376 | ||
377 | if (adev) { | |
378 | dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); | |
379 | return; | |
380 | } | |
381 | ||
382 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), | |
383 | spi->chip_select); | |
384 | } | |
385 | ||
b6fb8d3a MW |
386 | static int spi_dev_check(struct device *dev, void *data) |
387 | { | |
388 | struct spi_device *spi = to_spi_device(dev); | |
389 | struct spi_device *new_spi = data; | |
390 | ||
391 | if (spi->master == new_spi->master && | |
392 | spi->chip_select == new_spi->chip_select) | |
393 | return -EBUSY; | |
394 | return 0; | |
395 | } | |
396 | ||
dc87c98e GL |
397 | /** |
398 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
399 | * @spi: spi_device to register | |
400 | * | |
401 | * Companion function to spi_alloc_device. Devices allocated with | |
402 | * spi_alloc_device can be added onto the spi bus with this function. | |
403 | * | |
e48880e0 | 404 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
405 | */ |
406 | int spi_add_device(struct spi_device *spi) | |
407 | { | |
e48880e0 | 408 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
409 | struct spi_master *master = spi->master; |
410 | struct device *dev = master->dev.parent; | |
dc87c98e GL |
411 | int status; |
412 | ||
413 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 414 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
415 | dev_err(dev, "cs%d >= max %d\n", |
416 | spi->chip_select, | |
74317984 | 417 | master->num_chipselect); |
dc87c98e GL |
418 | return -EINVAL; |
419 | } | |
420 | ||
421 | /* Set the bus ID string */ | |
e13ac47b | 422 | spi_dev_set_name(spi); |
e48880e0 DB |
423 | |
424 | /* We need to make sure there's no other device with this | |
425 | * chipselect **BEFORE** we call setup(), else we'll trash | |
426 | * its configuration. Lock against concurrent add() calls. | |
427 | */ | |
428 | mutex_lock(&spi_add_lock); | |
429 | ||
b6fb8d3a MW |
430 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
431 | if (status) { | |
e48880e0 DB |
432 | dev_err(dev, "chipselect %d already in use\n", |
433 | spi->chip_select); | |
e48880e0 DB |
434 | goto done; |
435 | } | |
436 | ||
74317984 JCPV |
437 | if (master->cs_gpios) |
438 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
439 | ||
e48880e0 DB |
440 | /* Drivers may modify this initial i/o setup, but will |
441 | * normally rely on the device being setup. Devices | |
442 | * using SPI_CS_HIGH can't coexist well otherwise... | |
443 | */ | |
7d077197 | 444 | status = spi_setup(spi); |
dc87c98e | 445 | if (status < 0) { |
eb288a1f LW |
446 | dev_err(dev, "can't setup %s, status %d\n", |
447 | dev_name(&spi->dev), status); | |
e48880e0 | 448 | goto done; |
dc87c98e GL |
449 | } |
450 | ||
e48880e0 | 451 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 452 | status = device_add(&spi->dev); |
e48880e0 | 453 | if (status < 0) |
eb288a1f LW |
454 | dev_err(dev, "can't add %s, status %d\n", |
455 | dev_name(&spi->dev), status); | |
e48880e0 | 456 | else |
35f74fca | 457 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 458 | |
e48880e0 DB |
459 | done: |
460 | mutex_unlock(&spi_add_lock); | |
461 | return status; | |
dc87c98e GL |
462 | } |
463 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 464 | |
33e34dc6 DB |
465 | /** |
466 | * spi_new_device - instantiate one new SPI device | |
467 | * @master: Controller to which device is connected | |
468 | * @chip: Describes the SPI device | |
469 | * Context: can sleep | |
470 | * | |
471 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
472 | * after board init creates the hard-wired devices. Some development |
473 | * platforms may not be able to use spi_register_board_info though, and | |
474 | * this is exported so that for example a USB or parport based adapter | |
475 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 DB |
476 | * |
477 | * Returns the new device, or NULL. | |
8ae12a0d | 478 | */ |
e9d5a461 AB |
479 | struct spi_device *spi_new_device(struct spi_master *master, |
480 | struct spi_board_info *chip) | |
8ae12a0d DB |
481 | { |
482 | struct spi_device *proxy; | |
8ae12a0d DB |
483 | int status; |
484 | ||
082c8cb4 DB |
485 | /* NOTE: caller did any chip->bus_num checks necessary. |
486 | * | |
487 | * Also, unless we change the return value convention to use | |
488 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
489 | * suggests syslogged diagnostics are best here (ugh). | |
490 | */ | |
491 | ||
dc87c98e GL |
492 | proxy = spi_alloc_device(master); |
493 | if (!proxy) | |
8ae12a0d DB |
494 | return NULL; |
495 | ||
102eb975 GL |
496 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
497 | ||
8ae12a0d DB |
498 | proxy->chip_select = chip->chip_select; |
499 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 500 | proxy->mode = chip->mode; |
8ae12a0d | 501 | proxy->irq = chip->irq; |
102eb975 | 502 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
503 | proxy->dev.platform_data = (void *) chip->platform_data; |
504 | proxy->controller_data = chip->controller_data; | |
505 | proxy->controller_state = NULL; | |
8ae12a0d | 506 | |
dc87c98e | 507 | status = spi_add_device(proxy); |
8ae12a0d | 508 | if (status < 0) { |
dc87c98e GL |
509 | spi_dev_put(proxy); |
510 | return NULL; | |
8ae12a0d DB |
511 | } |
512 | ||
8ae12a0d DB |
513 | return proxy; |
514 | } | |
515 | EXPORT_SYMBOL_GPL(spi_new_device); | |
516 | ||
2b9603a0 FT |
517 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
518 | struct spi_board_info *bi) | |
519 | { | |
520 | struct spi_device *dev; | |
521 | ||
522 | if (master->bus_num != bi->bus_num) | |
523 | return; | |
524 | ||
525 | dev = spi_new_device(master, bi); | |
526 | if (!dev) | |
527 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
528 | bi->modalias); | |
529 | } | |
530 | ||
33e34dc6 DB |
531 | /** |
532 | * spi_register_board_info - register SPI devices for a given board | |
533 | * @info: array of chip descriptors | |
534 | * @n: how many descriptors are provided | |
535 | * Context: can sleep | |
536 | * | |
8ae12a0d DB |
537 | * Board-specific early init code calls this (probably during arch_initcall) |
538 | * with segments of the SPI device table. Any device nodes are created later, | |
539 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
540 | * this table of devices forever, so that reloading a controller driver will | |
541 | * not make Linux forget about these hard-wired devices. | |
542 | * | |
543 | * Other code can also call this, e.g. a particular add-on board might provide | |
544 | * SPI devices through its expansion connector, so code initializing that board | |
545 | * would naturally declare its SPI devices. | |
546 | * | |
547 | * The board info passed can safely be __initdata ... but be careful of | |
548 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
549 | */ | |
fd4a319b | 550 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 551 | { |
2b9603a0 FT |
552 | struct boardinfo *bi; |
553 | int i; | |
8ae12a0d | 554 | |
2b9603a0 | 555 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
556 | if (!bi) |
557 | return -ENOMEM; | |
8ae12a0d | 558 | |
2b9603a0 FT |
559 | for (i = 0; i < n; i++, bi++, info++) { |
560 | struct spi_master *master; | |
8ae12a0d | 561 | |
2b9603a0 FT |
562 | memcpy(&bi->board_info, info, sizeof(*info)); |
563 | mutex_lock(&board_lock); | |
564 | list_add_tail(&bi->list, &board_list); | |
565 | list_for_each_entry(master, &spi_master_list, list) | |
566 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
567 | mutex_unlock(&board_lock); | |
8ae12a0d | 568 | } |
2b9603a0 FT |
569 | |
570 | return 0; | |
8ae12a0d DB |
571 | } |
572 | ||
573 | /*-------------------------------------------------------------------------*/ | |
574 | ||
b158935f MB |
575 | static void spi_set_cs(struct spi_device *spi, bool enable) |
576 | { | |
577 | if (spi->mode & SPI_CS_HIGH) | |
578 | enable = !enable; | |
579 | ||
580 | if (spi->cs_gpio >= 0) | |
581 | gpio_set_value(spi->cs_gpio, !enable); | |
582 | else if (spi->master->set_cs) | |
583 | spi->master->set_cs(spi, !enable); | |
584 | } | |
585 | ||
2de440f5 | 586 | #ifdef CONFIG_HAS_DMA |
6ad45a27 MB |
587 | static int spi_map_buf(struct spi_master *master, struct device *dev, |
588 | struct sg_table *sgt, void *buf, size_t len, | |
589 | enum dma_data_direction dir) | |
590 | { | |
591 | const bool vmalloced_buf = is_vmalloc_addr(buf); | |
592 | const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len; | |
593 | const int sgs = DIV_ROUND_UP(len, desc_len); | |
594 | struct page *vm_page; | |
595 | void *sg_buf; | |
596 | size_t min; | |
597 | int i, ret; | |
598 | ||
599 | ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); | |
600 | if (ret != 0) | |
601 | return ret; | |
602 | ||
603 | for (i = 0; i < sgs; i++) { | |
604 | min = min_t(size_t, len, desc_len); | |
605 | ||
606 | if (vmalloced_buf) { | |
607 | vm_page = vmalloc_to_page(buf); | |
608 | if (!vm_page) { | |
609 | sg_free_table(sgt); | |
610 | return -ENOMEM; | |
611 | } | |
612 | sg_buf = page_address(vm_page) + | |
613 | ((size_t)buf & ~PAGE_MASK); | |
614 | } else { | |
615 | sg_buf = buf; | |
616 | } | |
617 | ||
618 | sg_set_buf(&sgt->sgl[i], sg_buf, min); | |
619 | ||
620 | buf += min; | |
621 | len -= min; | |
622 | } | |
623 | ||
624 | ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); | |
89e4b66a GU |
625 | if (!ret) |
626 | ret = -ENOMEM; | |
6ad45a27 MB |
627 | if (ret < 0) { |
628 | sg_free_table(sgt); | |
629 | return ret; | |
630 | } | |
631 | ||
632 | sgt->nents = ret; | |
633 | ||
634 | return 0; | |
635 | } | |
636 | ||
637 | static void spi_unmap_buf(struct spi_master *master, struct device *dev, | |
638 | struct sg_table *sgt, enum dma_data_direction dir) | |
639 | { | |
640 | if (sgt->orig_nents) { | |
641 | dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); | |
642 | sg_free_table(sgt); | |
643 | } | |
644 | } | |
645 | ||
2de440f5 | 646 | static int __spi_map_msg(struct spi_master *master, struct spi_message *msg) |
99adef31 | 647 | { |
99adef31 MB |
648 | struct device *tx_dev, *rx_dev; |
649 | struct spi_transfer *xfer; | |
6ad45a27 | 650 | int ret; |
3a2eba9b | 651 | |
6ad45a27 | 652 | if (!master->can_dma) |
99adef31 MB |
653 | return 0; |
654 | ||
3fc25421 GU |
655 | tx_dev = master->dma_tx->device->dev; |
656 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
657 | |
658 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
659 | if (!master->can_dma(master, msg->spi, xfer)) | |
660 | continue; | |
661 | ||
662 | if (xfer->tx_buf != NULL) { | |
6ad45a27 MB |
663 | ret = spi_map_buf(master, tx_dev, &xfer->tx_sg, |
664 | (void *)xfer->tx_buf, xfer->len, | |
665 | DMA_TO_DEVICE); | |
666 | if (ret != 0) | |
667 | return ret; | |
99adef31 MB |
668 | } |
669 | ||
670 | if (xfer->rx_buf != NULL) { | |
6ad45a27 MB |
671 | ret = spi_map_buf(master, rx_dev, &xfer->rx_sg, |
672 | xfer->rx_buf, xfer->len, | |
673 | DMA_FROM_DEVICE); | |
674 | if (ret != 0) { | |
675 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, | |
676 | DMA_TO_DEVICE); | |
677 | return ret; | |
99adef31 MB |
678 | } |
679 | } | |
680 | } | |
681 | ||
682 | master->cur_msg_mapped = true; | |
683 | ||
684 | return 0; | |
685 | } | |
686 | ||
687 | static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg) | |
688 | { | |
689 | struct spi_transfer *xfer; | |
690 | struct device *tx_dev, *rx_dev; | |
691 | ||
6ad45a27 | 692 | if (!master->cur_msg_mapped || !master->can_dma) |
99adef31 MB |
693 | return 0; |
694 | ||
3fc25421 GU |
695 | tx_dev = master->dma_tx->device->dev; |
696 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
697 | |
698 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
699 | if (!master->can_dma(master, msg->spi, xfer)) | |
700 | continue; | |
701 | ||
6ad45a27 MB |
702 | spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
703 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); | |
99adef31 MB |
704 | } |
705 | ||
706 | return 0; | |
707 | } | |
2de440f5 GU |
708 | #else /* !CONFIG_HAS_DMA */ |
709 | static inline int __spi_map_msg(struct spi_master *master, | |
710 | struct spi_message *msg) | |
711 | { | |
712 | return 0; | |
713 | } | |
714 | ||
715 | static inline int spi_unmap_msg(struct spi_master *master, | |
716 | struct spi_message *msg) | |
717 | { | |
718 | return 0; | |
719 | } | |
720 | #endif /* !CONFIG_HAS_DMA */ | |
721 | ||
722 | static int spi_map_msg(struct spi_master *master, struct spi_message *msg) | |
723 | { | |
724 | struct spi_transfer *xfer; | |
725 | void *tmp; | |
726 | unsigned int max_tx, max_rx; | |
727 | ||
728 | if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) { | |
729 | max_tx = 0; | |
730 | max_rx = 0; | |
731 | ||
732 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
733 | if ((master->flags & SPI_MASTER_MUST_TX) && | |
734 | !xfer->tx_buf) | |
735 | max_tx = max(xfer->len, max_tx); | |
736 | if ((master->flags & SPI_MASTER_MUST_RX) && | |
737 | !xfer->rx_buf) | |
738 | max_rx = max(xfer->len, max_rx); | |
739 | } | |
740 | ||
741 | if (max_tx) { | |
742 | tmp = krealloc(master->dummy_tx, max_tx, | |
743 | GFP_KERNEL | GFP_DMA); | |
744 | if (!tmp) | |
745 | return -ENOMEM; | |
746 | master->dummy_tx = tmp; | |
747 | memset(tmp, 0, max_tx); | |
748 | } | |
749 | ||
750 | if (max_rx) { | |
751 | tmp = krealloc(master->dummy_rx, max_rx, | |
752 | GFP_KERNEL | GFP_DMA); | |
753 | if (!tmp) | |
754 | return -ENOMEM; | |
755 | master->dummy_rx = tmp; | |
756 | } | |
757 | ||
758 | if (max_tx || max_rx) { | |
759 | list_for_each_entry(xfer, &msg->transfers, | |
760 | transfer_list) { | |
761 | if (!xfer->tx_buf) | |
762 | xfer->tx_buf = master->dummy_tx; | |
763 | if (!xfer->rx_buf) | |
764 | xfer->rx_buf = master->dummy_rx; | |
765 | } | |
766 | } | |
767 | } | |
768 | ||
769 | return __spi_map_msg(master, msg); | |
770 | } | |
99adef31 | 771 | |
b158935f MB |
772 | /* |
773 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
774 | * | |
775 | * This is a standard implementation of transfer_one_message() for | |
776 | * drivers which impelment a transfer_one() operation. It provides | |
777 | * standard handling of delays and chip select management. | |
778 | */ | |
779 | static int spi_transfer_one_message(struct spi_master *master, | |
780 | struct spi_message *msg) | |
781 | { | |
782 | struct spi_transfer *xfer; | |
b158935f MB |
783 | bool keep_cs = false; |
784 | int ret = 0; | |
16a0ce4e | 785 | int ms = 1; |
b158935f MB |
786 | |
787 | spi_set_cs(msg->spi, true); | |
788 | ||
789 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
790 | trace_spi_transfer_start(msg, xfer); | |
791 | ||
16735d02 | 792 | reinit_completion(&master->xfer_completion); |
b158935f MB |
793 | |
794 | ret = master->transfer_one(master, msg->spi, xfer); | |
795 | if (ret < 0) { | |
796 | dev_err(&msg->spi->dev, | |
797 | "SPI transfer failed: %d\n", ret); | |
798 | goto out; | |
799 | } | |
800 | ||
13a42798 AL |
801 | if (ret > 0) { |
802 | ret = 0; | |
16a0ce4e | 803 | ms = xfer->len * 8 * 1000 / xfer->speed_hz; |
eee668a9 | 804 | ms += ms + 100; /* some tolerance */ |
16a0ce4e MB |
805 | |
806 | ms = wait_for_completion_timeout(&master->xfer_completion, | |
807 | msecs_to_jiffies(ms)); | |
808 | } | |
809 | ||
810 | if (ms == 0) { | |
811 | dev_err(&msg->spi->dev, "SPI transfer timed out\n"); | |
812 | msg->status = -ETIMEDOUT; | |
13a42798 | 813 | } |
b158935f MB |
814 | |
815 | trace_spi_transfer_stop(msg, xfer); | |
816 | ||
817 | if (msg->status != -EINPROGRESS) | |
818 | goto out; | |
819 | ||
820 | if (xfer->delay_usecs) | |
821 | udelay(xfer->delay_usecs); | |
822 | ||
823 | if (xfer->cs_change) { | |
824 | if (list_is_last(&xfer->transfer_list, | |
825 | &msg->transfers)) { | |
826 | keep_cs = true; | |
827 | } else { | |
0b73aa63 MB |
828 | spi_set_cs(msg->spi, false); |
829 | udelay(10); | |
830 | spi_set_cs(msg->spi, true); | |
b158935f MB |
831 | } |
832 | } | |
833 | ||
834 | msg->actual_length += xfer->len; | |
835 | } | |
836 | ||
837 | out: | |
838 | if (ret != 0 || !keep_cs) | |
839 | spi_set_cs(msg->spi, false); | |
840 | ||
841 | if (msg->status == -EINPROGRESS) | |
842 | msg->status = ret; | |
843 | ||
844 | spi_finalize_current_message(master); | |
845 | ||
846 | return ret; | |
847 | } | |
848 | ||
849 | /** | |
850 | * spi_finalize_current_transfer - report completion of a transfer | |
2c675689 | 851 | * @master: the master reporting completion |
b158935f MB |
852 | * |
853 | * Called by SPI drivers using the core transfer_one_message() | |
854 | * implementation to notify it that the current interrupt driven | |
9e8f4882 | 855 | * transfer has finished and the next one may be scheduled. |
b158935f MB |
856 | */ |
857 | void spi_finalize_current_transfer(struct spi_master *master) | |
858 | { | |
859 | complete(&master->xfer_completion); | |
860 | } | |
861 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
862 | ||
ffbbdd21 LW |
863 | /** |
864 | * spi_pump_messages - kthread work function which processes spi message queue | |
865 | * @work: pointer to kthread work struct contained in the master struct | |
866 | * | |
867 | * This function checks if there is any spi message in the queue that | |
868 | * needs processing and if so call out to the driver to initialize hardware | |
869 | * and transfer each message. | |
870 | * | |
871 | */ | |
872 | static void spi_pump_messages(struct kthread_work *work) | |
873 | { | |
874 | struct spi_master *master = | |
875 | container_of(work, struct spi_master, pump_messages); | |
876 | unsigned long flags; | |
877 | bool was_busy = false; | |
878 | int ret; | |
879 | ||
880 | /* Lock queue and check for queue work */ | |
881 | spin_lock_irqsave(&master->queue_lock, flags); | |
882 | if (list_empty(&master->queue) || !master->running) { | |
b0b36b86 BF |
883 | if (!master->busy) { |
884 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
885 | return; | |
ffbbdd21 LW |
886 | } |
887 | master->busy = false; | |
888 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
3a2eba9b MB |
889 | kfree(master->dummy_rx); |
890 | master->dummy_rx = NULL; | |
891 | kfree(master->dummy_tx); | |
892 | master->dummy_tx = NULL; | |
b0b36b86 BF |
893 | if (master->unprepare_transfer_hardware && |
894 | master->unprepare_transfer_hardware(master)) | |
895 | dev_err(&master->dev, | |
896 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
897 | if (master->auto_runtime_pm) { |
898 | pm_runtime_mark_last_busy(master->dev.parent); | |
899 | pm_runtime_put_autosuspend(master->dev.parent); | |
900 | } | |
56ec1978 | 901 | trace_spi_master_idle(master); |
ffbbdd21 LW |
902 | return; |
903 | } | |
904 | ||
905 | /* Make sure we are not already running a message */ | |
906 | if (master->cur_msg) { | |
907 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
908 | return; | |
909 | } | |
910 | /* Extract head of queue */ | |
911 | master->cur_msg = | |
a89e2d27 | 912 | list_first_entry(&master->queue, struct spi_message, queue); |
ffbbdd21 LW |
913 | |
914 | list_del_init(&master->cur_msg->queue); | |
915 | if (master->busy) | |
916 | was_busy = true; | |
917 | else | |
918 | master->busy = true; | |
919 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
920 | ||
49834de2 MB |
921 | if (!was_busy && master->auto_runtime_pm) { |
922 | ret = pm_runtime_get_sync(master->dev.parent); | |
923 | if (ret < 0) { | |
924 | dev_err(&master->dev, "Failed to power device: %d\n", | |
925 | ret); | |
926 | return; | |
927 | } | |
928 | } | |
929 | ||
56ec1978 MB |
930 | if (!was_busy) |
931 | trace_spi_master_busy(master); | |
932 | ||
7dfd2bd7 | 933 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
934 | ret = master->prepare_transfer_hardware(master); |
935 | if (ret) { | |
936 | dev_err(&master->dev, | |
937 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
938 | |
939 | if (master->auto_runtime_pm) | |
940 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
941 | return; |
942 | } | |
943 | } | |
944 | ||
56ec1978 MB |
945 | trace_spi_message_start(master->cur_msg); |
946 | ||
2841a5fc MB |
947 | if (master->prepare_message) { |
948 | ret = master->prepare_message(master, master->cur_msg); | |
949 | if (ret) { | |
950 | dev_err(&master->dev, | |
951 | "failed to prepare message: %d\n", ret); | |
952 | master->cur_msg->status = ret; | |
953 | spi_finalize_current_message(master); | |
954 | return; | |
955 | } | |
956 | master->cur_msg_prepared = true; | |
957 | } | |
958 | ||
99adef31 MB |
959 | ret = spi_map_msg(master, master->cur_msg); |
960 | if (ret) { | |
961 | master->cur_msg->status = ret; | |
962 | spi_finalize_current_message(master); | |
963 | return; | |
964 | } | |
965 | ||
ffbbdd21 LW |
966 | ret = master->transfer_one_message(master, master->cur_msg); |
967 | if (ret) { | |
968 | dev_err(&master->dev, | |
1f802f82 | 969 | "failed to transfer one message from queue\n"); |
ffbbdd21 LW |
970 | return; |
971 | } | |
972 | } | |
973 | ||
974 | static int spi_init_queue(struct spi_master *master) | |
975 | { | |
976 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
977 | ||
978 | INIT_LIST_HEAD(&master->queue); | |
979 | spin_lock_init(&master->queue_lock); | |
980 | ||
981 | master->running = false; | |
982 | master->busy = false; | |
983 | ||
984 | init_kthread_worker(&master->kworker); | |
985 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 986 | &master->kworker, "%s", |
ffbbdd21 LW |
987 | dev_name(&master->dev)); |
988 | if (IS_ERR(master->kworker_task)) { | |
989 | dev_err(&master->dev, "failed to create message pump task\n"); | |
990 | return -ENOMEM; | |
991 | } | |
992 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
993 | ||
994 | /* | |
995 | * Master config will indicate if this controller should run the | |
996 | * message pump with high (realtime) priority to reduce the transfer | |
997 | * latency on the bus by minimising the delay between a transfer | |
998 | * request and the scheduling of the message pump thread. Without this | |
999 | * setting the message pump thread will remain at default priority. | |
1000 | */ | |
1001 | if (master->rt) { | |
1002 | dev_info(&master->dev, | |
1003 | "will run message pump with realtime priority\n"); | |
1004 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
1005 | } | |
1006 | ||
1007 | return 0; | |
1008 | } | |
1009 | ||
1010 | /** | |
1011 | * spi_get_next_queued_message() - called by driver to check for queued | |
1012 | * messages | |
1013 | * @master: the master to check for queued messages | |
1014 | * | |
1015 | * If there are more messages in the queue, the next message is returned from | |
1016 | * this call. | |
1017 | */ | |
1018 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
1019 | { | |
1020 | struct spi_message *next; | |
1021 | unsigned long flags; | |
1022 | ||
1023 | /* get a pointer to the next message, if any */ | |
1024 | spin_lock_irqsave(&master->queue_lock, flags); | |
1cfd97f9 AL |
1025 | next = list_first_entry_or_null(&master->queue, struct spi_message, |
1026 | queue); | |
ffbbdd21 LW |
1027 | spin_unlock_irqrestore(&master->queue_lock, flags); |
1028 | ||
1029 | return next; | |
1030 | } | |
1031 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
1032 | ||
1033 | /** | |
1034 | * spi_finalize_current_message() - the current message is complete | |
1035 | * @master: the master to return the message to | |
1036 | * | |
1037 | * Called by the driver to notify the core that the message in the front of the | |
1038 | * queue is complete and can be removed from the queue. | |
1039 | */ | |
1040 | void spi_finalize_current_message(struct spi_master *master) | |
1041 | { | |
1042 | struct spi_message *mesg; | |
1043 | unsigned long flags; | |
2841a5fc | 1044 | int ret; |
ffbbdd21 LW |
1045 | |
1046 | spin_lock_irqsave(&master->queue_lock, flags); | |
1047 | mesg = master->cur_msg; | |
1048 | master->cur_msg = NULL; | |
1049 | ||
1050 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1051 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1052 | ||
99adef31 MB |
1053 | spi_unmap_msg(master, mesg); |
1054 | ||
2841a5fc MB |
1055 | if (master->cur_msg_prepared && master->unprepare_message) { |
1056 | ret = master->unprepare_message(master, mesg); | |
1057 | if (ret) { | |
1058 | dev_err(&master->dev, | |
1059 | "failed to unprepare message: %d\n", ret); | |
1060 | } | |
1061 | } | |
1062 | master->cur_msg_prepared = false; | |
1063 | ||
ffbbdd21 LW |
1064 | mesg->state = NULL; |
1065 | if (mesg->complete) | |
1066 | mesg->complete(mesg->context); | |
56ec1978 MB |
1067 | |
1068 | trace_spi_message_done(mesg); | |
ffbbdd21 LW |
1069 | } |
1070 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
1071 | ||
1072 | static int spi_start_queue(struct spi_master *master) | |
1073 | { | |
1074 | unsigned long flags; | |
1075 | ||
1076 | spin_lock_irqsave(&master->queue_lock, flags); | |
1077 | ||
1078 | if (master->running || master->busy) { | |
1079 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1080 | return -EBUSY; | |
1081 | } | |
1082 | ||
1083 | master->running = true; | |
1084 | master->cur_msg = NULL; | |
1085 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1086 | ||
1087 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1088 | ||
1089 | return 0; | |
1090 | } | |
1091 | ||
1092 | static int spi_stop_queue(struct spi_master *master) | |
1093 | { | |
1094 | unsigned long flags; | |
1095 | unsigned limit = 500; | |
1096 | int ret = 0; | |
1097 | ||
1098 | spin_lock_irqsave(&master->queue_lock, flags); | |
1099 | ||
1100 | /* | |
1101 | * This is a bit lame, but is optimized for the common execution path. | |
1102 | * A wait_queue on the master->busy could be used, but then the common | |
1103 | * execution path (pump_messages) would be required to call wake_up or | |
1104 | * friends on every SPI message. Do this instead. | |
1105 | */ | |
1106 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
1107 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
f97b26b0 | 1108 | usleep_range(10000, 11000); |
ffbbdd21 LW |
1109 | spin_lock_irqsave(&master->queue_lock, flags); |
1110 | } | |
1111 | ||
1112 | if (!list_empty(&master->queue) || master->busy) | |
1113 | ret = -EBUSY; | |
1114 | else | |
1115 | master->running = false; | |
1116 | ||
1117 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1118 | ||
1119 | if (ret) { | |
1120 | dev_warn(&master->dev, | |
1121 | "could not stop message queue\n"); | |
1122 | return ret; | |
1123 | } | |
1124 | return ret; | |
1125 | } | |
1126 | ||
1127 | static int spi_destroy_queue(struct spi_master *master) | |
1128 | { | |
1129 | int ret; | |
1130 | ||
1131 | ret = spi_stop_queue(master); | |
1132 | ||
1133 | /* | |
1134 | * flush_kthread_worker will block until all work is done. | |
1135 | * If the reason that stop_queue timed out is that the work will never | |
1136 | * finish, then it does no good to call flush/stop thread, so | |
1137 | * return anyway. | |
1138 | */ | |
1139 | if (ret) { | |
1140 | dev_err(&master->dev, "problem destroying queue\n"); | |
1141 | return ret; | |
1142 | } | |
1143 | ||
1144 | flush_kthread_worker(&master->kworker); | |
1145 | kthread_stop(master->kworker_task); | |
1146 | ||
1147 | return 0; | |
1148 | } | |
1149 | ||
1150 | /** | |
1151 | * spi_queued_transfer - transfer function for queued transfers | |
1152 | * @spi: spi device which is requesting transfer | |
1153 | * @msg: spi message which is to handled is queued to driver queue | |
1154 | */ | |
1155 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
1156 | { | |
1157 | struct spi_master *master = spi->master; | |
1158 | unsigned long flags; | |
1159 | ||
1160 | spin_lock_irqsave(&master->queue_lock, flags); | |
1161 | ||
1162 | if (!master->running) { | |
1163 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1164 | return -ESHUTDOWN; | |
1165 | } | |
1166 | msg->actual_length = 0; | |
1167 | msg->status = -EINPROGRESS; | |
1168 | ||
1169 | list_add_tail(&msg->queue, &master->queue); | |
96b3eace | 1170 | if (!master->busy) |
ffbbdd21 LW |
1171 | queue_kthread_work(&master->kworker, &master->pump_messages); |
1172 | ||
1173 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1174 | return 0; | |
1175 | } | |
1176 | ||
1177 | static int spi_master_initialize_queue(struct spi_master *master) | |
1178 | { | |
1179 | int ret; | |
1180 | ||
ffbbdd21 | 1181 | master->transfer = spi_queued_transfer; |
b158935f MB |
1182 | if (!master->transfer_one_message) |
1183 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
1184 | |
1185 | /* Initialize and start queue */ | |
1186 | ret = spi_init_queue(master); | |
1187 | if (ret) { | |
1188 | dev_err(&master->dev, "problem initializing queue\n"); | |
1189 | goto err_init_queue; | |
1190 | } | |
c3676d5c | 1191 | master->queued = true; |
ffbbdd21 LW |
1192 | ret = spi_start_queue(master); |
1193 | if (ret) { | |
1194 | dev_err(&master->dev, "problem starting queue\n"); | |
1195 | goto err_start_queue; | |
1196 | } | |
1197 | ||
1198 | return 0; | |
1199 | ||
1200 | err_start_queue: | |
ffbbdd21 | 1201 | spi_destroy_queue(master); |
c3676d5c | 1202 | err_init_queue: |
ffbbdd21 LW |
1203 | return ret; |
1204 | } | |
1205 | ||
1206 | /*-------------------------------------------------------------------------*/ | |
1207 | ||
7cb94361 | 1208 | #if defined(CONFIG_OF) |
d57a4282 GL |
1209 | /** |
1210 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
1211 | * @master: Pointer to spi_master device | |
1212 | * | |
1213 | * Registers an spi_device for each child node of master node which has a 'reg' | |
1214 | * property. | |
1215 | */ | |
1216 | static void of_register_spi_devices(struct spi_master *master) | |
1217 | { | |
1218 | struct spi_device *spi; | |
1219 | struct device_node *nc; | |
d57a4282 | 1220 | int rc; |
89da4293 | 1221 | u32 value; |
d57a4282 GL |
1222 | |
1223 | if (!master->dev.of_node) | |
1224 | return; | |
1225 | ||
f3b6159e | 1226 | for_each_available_child_of_node(master->dev.of_node, nc) { |
d57a4282 GL |
1227 | /* Alloc an spi_device */ |
1228 | spi = spi_alloc_device(master); | |
1229 | if (!spi) { | |
1230 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
1231 | nc->full_name); | |
1232 | spi_dev_put(spi); | |
1233 | continue; | |
1234 | } | |
1235 | ||
1236 | /* Select device driver */ | |
1237 | if (of_modalias_node(nc, spi->modalias, | |
1238 | sizeof(spi->modalias)) < 0) { | |
1239 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
1240 | nc->full_name); | |
1241 | spi_dev_put(spi); | |
1242 | continue; | |
1243 | } | |
1244 | ||
1245 | /* Device address */ | |
89da4293 TP |
1246 | rc = of_property_read_u32(nc, "reg", &value); |
1247 | if (rc) { | |
1248 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
1249 | nc->full_name, rc); | |
d57a4282 GL |
1250 | spi_dev_put(spi); |
1251 | continue; | |
1252 | } | |
89da4293 | 1253 | spi->chip_select = value; |
d57a4282 GL |
1254 | |
1255 | /* Mode (clock phase/polarity/etc.) */ | |
1256 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1257 | spi->mode |= SPI_CPHA; | |
1258 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1259 | spi->mode |= SPI_CPOL; | |
1260 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1261 | spi->mode |= SPI_CS_HIGH; | |
c20151df LPC |
1262 | if (of_find_property(nc, "spi-3wire", NULL)) |
1263 | spi->mode |= SPI_3WIRE; | |
cd6339e6 ZQ |
1264 | if (of_find_property(nc, "spi-lsb-first", NULL)) |
1265 | spi->mode |= SPI_LSB_FIRST; | |
d57a4282 | 1266 | |
f477b7fb | 1267 | /* Device DUAL/QUAD mode */ |
89da4293 TP |
1268 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { |
1269 | switch (value) { | |
1270 | case 1: | |
a822e99c | 1271 | break; |
89da4293 | 1272 | case 2: |
a822e99c MB |
1273 | spi->mode |= SPI_TX_DUAL; |
1274 | break; | |
89da4293 | 1275 | case 4: |
a822e99c MB |
1276 | spi->mode |= SPI_TX_QUAD; |
1277 | break; | |
1278 | default: | |
80874d8c GU |
1279 | dev_warn(&master->dev, |
1280 | "spi-tx-bus-width %d not supported\n", | |
1281 | value); | |
1282 | break; | |
a822e99c | 1283 | } |
f477b7fb | 1284 | } |
1285 | ||
89da4293 TP |
1286 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { |
1287 | switch (value) { | |
1288 | case 1: | |
a822e99c | 1289 | break; |
89da4293 | 1290 | case 2: |
a822e99c MB |
1291 | spi->mode |= SPI_RX_DUAL; |
1292 | break; | |
89da4293 | 1293 | case 4: |
a822e99c MB |
1294 | spi->mode |= SPI_RX_QUAD; |
1295 | break; | |
1296 | default: | |
80874d8c GU |
1297 | dev_warn(&master->dev, |
1298 | "spi-rx-bus-width %d not supported\n", | |
1299 | value); | |
1300 | break; | |
a822e99c | 1301 | } |
f477b7fb | 1302 | } |
1303 | ||
d57a4282 | 1304 | /* Device speed */ |
89da4293 TP |
1305 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); |
1306 | if (rc) { | |
1307 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1308 | nc->full_name, rc); | |
d57a4282 GL |
1309 | spi_dev_put(spi); |
1310 | continue; | |
1311 | } | |
89da4293 | 1312 | spi->max_speed_hz = value; |
d57a4282 GL |
1313 | |
1314 | /* IRQ */ | |
1315 | spi->irq = irq_of_parse_and_map(nc, 0); | |
1316 | ||
1317 | /* Store a pointer to the node in the device structure */ | |
1318 | of_node_get(nc); | |
1319 | spi->dev.of_node = nc; | |
1320 | ||
1321 | /* Register the new device */ | |
70fac17c | 1322 | request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias); |
d57a4282 GL |
1323 | rc = spi_add_device(spi); |
1324 | if (rc) { | |
1325 | dev_err(&master->dev, "spi_device register error %s\n", | |
1326 | nc->full_name); | |
1327 | spi_dev_put(spi); | |
1328 | } | |
1329 | ||
1330 | } | |
1331 | } | |
1332 | #else | |
1333 | static void of_register_spi_devices(struct spi_master *master) { } | |
1334 | #endif | |
1335 | ||
64bee4d2 MW |
1336 | #ifdef CONFIG_ACPI |
1337 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1338 | { | |
1339 | struct spi_device *spi = data; | |
1340 | ||
1341 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1342 | struct acpi_resource_spi_serialbus *sb; | |
1343 | ||
1344 | sb = &ares->data.spi_serial_bus; | |
1345 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1346 | spi->chip_select = sb->device_selection; | |
1347 | spi->max_speed_hz = sb->connection_speed; | |
1348 | ||
1349 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1350 | spi->mode |= SPI_CPHA; | |
1351 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1352 | spi->mode |= SPI_CPOL; | |
1353 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1354 | spi->mode |= SPI_CS_HIGH; | |
1355 | } | |
1356 | } else if (spi->irq < 0) { | |
1357 | struct resource r; | |
1358 | ||
1359 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1360 | spi->irq = r.start; | |
1361 | } | |
1362 | ||
1363 | /* Always tell the ACPI core to skip this resource */ | |
1364 | return 1; | |
1365 | } | |
1366 | ||
1367 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1368 | void *data, void **return_value) | |
1369 | { | |
1370 | struct spi_master *master = data; | |
1371 | struct list_head resource_list; | |
1372 | struct acpi_device *adev; | |
1373 | struct spi_device *spi; | |
1374 | int ret; | |
1375 | ||
1376 | if (acpi_bus_get_device(handle, &adev)) | |
1377 | return AE_OK; | |
1378 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1379 | return AE_OK; | |
1380 | ||
1381 | spi = spi_alloc_device(master); | |
1382 | if (!spi) { | |
1383 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1384 | dev_name(&adev->dev)); | |
1385 | return AE_NO_MEMORY; | |
1386 | } | |
1387 | ||
7b199811 | 1388 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1389 | spi->irq = -1; |
1390 | ||
1391 | INIT_LIST_HEAD(&resource_list); | |
1392 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1393 | acpi_spi_add_resource, spi); | |
1394 | acpi_dev_free_resource_list(&resource_list); | |
1395 | ||
1396 | if (ret < 0 || !spi->max_speed_hz) { | |
1397 | spi_dev_put(spi); | |
1398 | return AE_OK; | |
1399 | } | |
1400 | ||
33cf00e5 | 1401 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1402 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1403 | if (spi_add_device(spi)) { |
33cf00e5 | 1404 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1405 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
1406 | dev_name(&adev->dev)); | |
1407 | spi_dev_put(spi); | |
1408 | } | |
1409 | ||
1410 | return AE_OK; | |
1411 | } | |
1412 | ||
1413 | static void acpi_register_spi_devices(struct spi_master *master) | |
1414 | { | |
1415 | acpi_status status; | |
1416 | acpi_handle handle; | |
1417 | ||
29896178 | 1418 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1419 | if (!handle) |
1420 | return; | |
1421 | ||
1422 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1423 | acpi_spi_add_device, NULL, | |
1424 | master, NULL); | |
1425 | if (ACPI_FAILURE(status)) | |
1426 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1427 | } | |
1428 | #else | |
1429 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1430 | #endif /* CONFIG_ACPI */ | |
1431 | ||
49dce689 | 1432 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1433 | { |
1434 | struct spi_master *master; | |
1435 | ||
49dce689 | 1436 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1437 | kfree(master); |
1438 | } | |
1439 | ||
1440 | static struct class spi_master_class = { | |
1441 | .name = "spi_master", | |
1442 | .owner = THIS_MODULE, | |
49dce689 | 1443 | .dev_release = spi_master_release, |
8ae12a0d DB |
1444 | }; |
1445 | ||
1446 | ||
ffbbdd21 | 1447 | |
8ae12a0d DB |
1448 | /** |
1449 | * spi_alloc_master - allocate SPI master controller | |
1450 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1451 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1452 | * memory is in the driver_data field of the returned device, |
0c868461 | 1453 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1454 | * Context: can sleep |
8ae12a0d DB |
1455 | * |
1456 | * This call is used only by SPI master controller drivers, which are the | |
1457 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1458 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1459 | * |
1460 | * This must be called from context that can sleep. It returns the SPI | |
1461 | * master structure on success, else NULL. | |
1462 | * | |
1463 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1464 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1465 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1466 | * leak. | |
8ae12a0d | 1467 | */ |
e9d5a461 | 1468 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1469 | { |
1470 | struct spi_master *master; | |
1471 | ||
0c868461 DB |
1472 | if (!dev) |
1473 | return NULL; | |
1474 | ||
5fe5f05e | 1475 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1476 | if (!master) |
1477 | return NULL; | |
1478 | ||
49dce689 | 1479 | device_initialize(&master->dev); |
1e8a52e1 GL |
1480 | master->bus_num = -1; |
1481 | master->num_chipselect = 1; | |
49dce689 TJ |
1482 | master->dev.class = &spi_master_class; |
1483 | master->dev.parent = get_device(dev); | |
0c868461 | 1484 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1485 | |
1486 | return master; | |
1487 | } | |
1488 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1489 | ||
74317984 JCPV |
1490 | #ifdef CONFIG_OF |
1491 | static int of_spi_register_master(struct spi_master *master) | |
1492 | { | |
e80beb27 | 1493 | int nb, i, *cs; |
74317984 JCPV |
1494 | struct device_node *np = master->dev.of_node; |
1495 | ||
1496 | if (!np) | |
1497 | return 0; | |
1498 | ||
1499 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1500 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1501 | |
8ec5d84e AL |
1502 | /* Return error only for an incorrectly formed cs-gpios property */ |
1503 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1504 | return 0; |
8ec5d84e AL |
1505 | else if (nb < 0) |
1506 | return nb; | |
74317984 JCPV |
1507 | |
1508 | cs = devm_kzalloc(&master->dev, | |
1509 | sizeof(int) * master->num_chipselect, | |
1510 | GFP_KERNEL); | |
1511 | master->cs_gpios = cs; | |
1512 | ||
1513 | if (!master->cs_gpios) | |
1514 | return -ENOMEM; | |
1515 | ||
0da83bb1 | 1516 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1517 | cs[i] = -ENOENT; |
74317984 JCPV |
1518 | |
1519 | for (i = 0; i < nb; i++) | |
1520 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1521 | ||
1522 | return 0; | |
1523 | } | |
1524 | #else | |
1525 | static int of_spi_register_master(struct spi_master *master) | |
1526 | { | |
1527 | return 0; | |
1528 | } | |
1529 | #endif | |
1530 | ||
8ae12a0d DB |
1531 | /** |
1532 | * spi_register_master - register SPI master controller | |
1533 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1534 | * Context: can sleep |
8ae12a0d DB |
1535 | * |
1536 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1537 | * such as the platform bus. The final stage of probe() in that code | |
1538 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1539 | * | |
1540 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1541 | * and board-specific addressing for SPI devices combines those numbers | |
1542 | * with chip select numbers. Since SPI does not directly support dynamic | |
1543 | * device identification, boards need configuration tables telling which | |
1544 | * chip is at which address. | |
1545 | * | |
1546 | * This must be called from context that can sleep. It returns zero on | |
1547 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1548 | * After a successful return, the caller is responsible for calling |
1549 | * spi_unregister_master(). | |
8ae12a0d | 1550 | */ |
e9d5a461 | 1551 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1552 | { |
e44a45ae | 1553 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1554 | struct device *dev = master->dev.parent; |
2b9603a0 | 1555 | struct boardinfo *bi; |
8ae12a0d DB |
1556 | int status = -ENODEV; |
1557 | int dynamic = 0; | |
1558 | ||
0c868461 DB |
1559 | if (!dev) |
1560 | return -ENODEV; | |
1561 | ||
74317984 JCPV |
1562 | status = of_spi_register_master(master); |
1563 | if (status) | |
1564 | return status; | |
1565 | ||
082c8cb4 DB |
1566 | /* even if it's just one always-selected device, there must |
1567 | * be at least one chipselect | |
1568 | */ | |
1569 | if (master->num_chipselect == 0) | |
1570 | return -EINVAL; | |
1571 | ||
bb29785e GL |
1572 | if ((master->bus_num < 0) && master->dev.of_node) |
1573 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1574 | ||
8ae12a0d | 1575 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1576 | if (master->bus_num < 0) { |
082c8cb4 DB |
1577 | /* FIXME switch to an IDR based scheme, something like |
1578 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1579 | */ | |
8ae12a0d | 1580 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1581 | dynamic = 1; |
8ae12a0d DB |
1582 | } |
1583 | ||
cf32b71e ES |
1584 | spin_lock_init(&master->bus_lock_spinlock); |
1585 | mutex_init(&master->bus_lock_mutex); | |
1586 | master->bus_lock_flag = 0; | |
b158935f | 1587 | init_completion(&master->xfer_completion); |
6ad45a27 MB |
1588 | if (!master->max_dma_len) |
1589 | master->max_dma_len = INT_MAX; | |
cf32b71e | 1590 | |
8ae12a0d DB |
1591 | /* register the device, then userspace will see it. |
1592 | * registration fails if the bus ID is in use. | |
1593 | */ | |
35f74fca | 1594 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1595 | status = device_add(&master->dev); |
b885244e | 1596 | if (status < 0) |
8ae12a0d | 1597 | goto done; |
35f74fca | 1598 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1599 | dynamic ? " (dynamic)" : ""); |
1600 | ||
ffbbdd21 LW |
1601 | /* If we're using a queued driver, start the queue */ |
1602 | if (master->transfer) | |
1603 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1604 | else { | |
1605 | status = spi_master_initialize_queue(master); | |
1606 | if (status) { | |
e93b0724 | 1607 | device_del(&master->dev); |
ffbbdd21 LW |
1608 | goto done; |
1609 | } | |
1610 | } | |
1611 | ||
2b9603a0 FT |
1612 | mutex_lock(&board_lock); |
1613 | list_add_tail(&master->list, &spi_master_list); | |
1614 | list_for_each_entry(bi, &board_list, list) | |
1615 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1616 | mutex_unlock(&board_lock); | |
1617 | ||
64bee4d2 | 1618 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1619 | of_register_spi_devices(master); |
64bee4d2 | 1620 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1621 | done: |
1622 | return status; | |
1623 | } | |
1624 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1625 | ||
666d5b4c MB |
1626 | static void devm_spi_unregister(struct device *dev, void *res) |
1627 | { | |
1628 | spi_unregister_master(*(struct spi_master **)res); | |
1629 | } | |
1630 | ||
1631 | /** | |
1632 | * dev_spi_register_master - register managed SPI master controller | |
1633 | * @dev: device managing SPI master | |
1634 | * @master: initialized master, originally from spi_alloc_master() | |
1635 | * Context: can sleep | |
1636 | * | |
1637 | * Register a SPI device as with spi_register_master() which will | |
1638 | * automatically be unregister | |
1639 | */ | |
1640 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1641 | { | |
1642 | struct spi_master **ptr; | |
1643 | int ret; | |
1644 | ||
1645 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1646 | if (!ptr) | |
1647 | return -ENOMEM; | |
1648 | ||
1649 | ret = spi_register_master(master); | |
4b92894e | 1650 | if (!ret) { |
666d5b4c MB |
1651 | *ptr = master; |
1652 | devres_add(dev, ptr); | |
1653 | } else { | |
1654 | devres_free(ptr); | |
1655 | } | |
1656 | ||
1657 | return ret; | |
1658 | } | |
1659 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1660 | ||
34860089 | 1661 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1662 | { |
34860089 | 1663 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1664 | return 0; |
1665 | } | |
1666 | ||
1667 | /** | |
1668 | * spi_unregister_master - unregister SPI master controller | |
1669 | * @master: the master being unregistered | |
33e34dc6 | 1670 | * Context: can sleep |
8ae12a0d DB |
1671 | * |
1672 | * This call is used only by SPI master controller drivers, which are the | |
1673 | * only ones directly touching chip registers. | |
1674 | * | |
1675 | * This must be called from context that can sleep. | |
1676 | */ | |
1677 | void spi_unregister_master(struct spi_master *master) | |
1678 | { | |
89fc9a1a JG |
1679 | int dummy; |
1680 | ||
ffbbdd21 LW |
1681 | if (master->queued) { |
1682 | if (spi_destroy_queue(master)) | |
1683 | dev_err(&master->dev, "queue remove failed\n"); | |
1684 | } | |
1685 | ||
2b9603a0 FT |
1686 | mutex_lock(&board_lock); |
1687 | list_del(&master->list); | |
1688 | mutex_unlock(&board_lock); | |
1689 | ||
97dbf37d | 1690 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1691 | device_unregister(&master->dev); |
8ae12a0d DB |
1692 | } |
1693 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1694 | ||
ffbbdd21 LW |
1695 | int spi_master_suspend(struct spi_master *master) |
1696 | { | |
1697 | int ret; | |
1698 | ||
1699 | /* Basically no-ops for non-queued masters */ | |
1700 | if (!master->queued) | |
1701 | return 0; | |
1702 | ||
1703 | ret = spi_stop_queue(master); | |
1704 | if (ret) | |
1705 | dev_err(&master->dev, "queue stop failed\n"); | |
1706 | ||
1707 | return ret; | |
1708 | } | |
1709 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1710 | ||
1711 | int spi_master_resume(struct spi_master *master) | |
1712 | { | |
1713 | int ret; | |
1714 | ||
1715 | if (!master->queued) | |
1716 | return 0; | |
1717 | ||
1718 | ret = spi_start_queue(master); | |
1719 | if (ret) | |
1720 | dev_err(&master->dev, "queue restart failed\n"); | |
1721 | ||
1722 | return ret; | |
1723 | } | |
1724 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1725 | ||
9f3b795a | 1726 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1727 | { |
1728 | struct spi_master *m; | |
9f3b795a | 1729 | const u16 *bus_num = data; |
5ed2c832 DY |
1730 | |
1731 | m = container_of(dev, struct spi_master, dev); | |
1732 | return m->bus_num == *bus_num; | |
1733 | } | |
1734 | ||
8ae12a0d DB |
1735 | /** |
1736 | * spi_busnum_to_master - look up master associated with bus_num | |
1737 | * @bus_num: the master's bus number | |
33e34dc6 | 1738 | * Context: can sleep |
8ae12a0d DB |
1739 | * |
1740 | * This call may be used with devices that are registered after | |
1741 | * arch init time. It returns a refcounted pointer to the relevant | |
1742 | * spi_master (which the caller must release), or NULL if there is | |
1743 | * no such master registered. | |
1744 | */ | |
1745 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1746 | { | |
49dce689 | 1747 | struct device *dev; |
1e9a51dc | 1748 | struct spi_master *master = NULL; |
5ed2c832 | 1749 | |
695794ae | 1750 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1751 | __spi_master_match); |
1752 | if (dev) | |
1753 | master = container_of(dev, struct spi_master, dev); | |
1754 | /* reference got in class_find_device */ | |
1e9a51dc | 1755 | return master; |
8ae12a0d DB |
1756 | } |
1757 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1758 | ||
1759 | ||
1760 | /*-------------------------------------------------------------------------*/ | |
1761 | ||
7d077197 DB |
1762 | /* Core methods for SPI master protocol drivers. Some of the |
1763 | * other core methods are currently defined as inline functions. | |
1764 | */ | |
1765 | ||
1766 | /** | |
1767 | * spi_setup - setup SPI mode and clock rate | |
1768 | * @spi: the device whose settings are being modified | |
1769 | * Context: can sleep, and no requests are queued to the device | |
1770 | * | |
1771 | * SPI protocol drivers may need to update the transfer mode if the | |
1772 | * device doesn't work with its default. They may likewise need | |
1773 | * to update clock rates or word sizes from initial values. This function | |
1774 | * changes those settings, and must be called from a context that can sleep. | |
1775 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
1776 | * effect the next time the device is selected and data is transferred to | |
1777 | * or from it. When this function returns, the spi device is deselected. | |
1778 | * | |
1779 | * Note that this call will fail if the protocol driver specifies an option | |
1780 | * that the underlying controller or its driver does not support. For | |
1781 | * example, not all hardware supports wire transfers using nine bit words, | |
1782 | * LSB-first wire encoding, or active-high chipselects. | |
1783 | */ | |
1784 | int spi_setup(struct spi_device *spi) | |
1785 | { | |
83596fbe | 1786 | unsigned bad_bits, ugly_bits; |
caae070c | 1787 | int status = 0; |
7d077197 | 1788 | |
f477b7fb | 1789 | /* check mode to prevent that DUAL and QUAD set at the same time |
1790 | */ | |
1791 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
1792 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
1793 | dev_err(&spi->dev, | |
1794 | "setup: can not select dual and quad at the same time\n"); | |
1795 | return -EINVAL; | |
1796 | } | |
1797 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
1798 | */ | |
1799 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
1800 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
1801 | return -EINVAL; | |
e7db06b5 DB |
1802 | /* help drivers fail *cleanly* when they need options |
1803 | * that aren't supported with their current master | |
1804 | */ | |
1805 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
83596fbe GU |
1806 | ugly_bits = bad_bits & |
1807 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); | |
1808 | if (ugly_bits) { | |
1809 | dev_warn(&spi->dev, | |
1810 | "setup: ignoring unsupported mode bits %x\n", | |
1811 | ugly_bits); | |
1812 | spi->mode &= ~ugly_bits; | |
1813 | bad_bits &= ~ugly_bits; | |
1814 | } | |
e7db06b5 | 1815 | if (bad_bits) { |
eb288a1f | 1816 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1817 | bad_bits); |
1818 | return -EINVAL; | |
1819 | } | |
1820 | ||
7d077197 DB |
1821 | if (!spi->bits_per_word) |
1822 | spi->bits_per_word = 8; | |
1823 | ||
052eb2d4 AL |
1824 | if (!spi->max_speed_hz) |
1825 | spi->max_speed_hz = spi->master->max_speed_hz; | |
1826 | ||
caae070c LD |
1827 | if (spi->master->setup) |
1828 | status = spi->master->setup(spi); | |
7d077197 | 1829 | |
5fe5f05e | 1830 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1831 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
1832 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
1833 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
1834 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
1835 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
1836 | spi->bits_per_word, spi->max_speed_hz, | |
1837 | status); | |
1838 | ||
1839 | return status; | |
1840 | } | |
1841 | EXPORT_SYMBOL_GPL(spi_setup); | |
1842 | ||
90808738 | 1843 | static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
cf32b71e ES |
1844 | { |
1845 | struct spi_master *master = spi->master; | |
e6811d1d | 1846 | struct spi_transfer *xfer; |
6ea31293 | 1847 | int w_size; |
cf32b71e | 1848 | |
24a0013a MB |
1849 | if (list_empty(&message->transfers)) |
1850 | return -EINVAL; | |
24a0013a | 1851 | |
cf32b71e ES |
1852 | /* Half-duplex links include original MicroWire, and ones with |
1853 | * only one data pin like SPI_3WIRE (switches direction) or where | |
1854 | * either MOSI or MISO is missing. They can also be caused by | |
1855 | * software limitations. | |
1856 | */ | |
1857 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
1858 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
1859 | unsigned flags = master->flags; |
1860 | ||
1861 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
1862 | if (xfer->rx_buf && xfer->tx_buf) | |
1863 | return -EINVAL; | |
1864 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
1865 | return -EINVAL; | |
1866 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
1867 | return -EINVAL; | |
1868 | } | |
1869 | } | |
1870 | ||
e6811d1d | 1871 | /** |
059b8ffe LD |
1872 | * Set transfer bits_per_word and max speed as spi device default if |
1873 | * it is not set for this transfer. | |
f477b7fb | 1874 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1875 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1876 | */ |
1877 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1878 | message->frame_length += xfer->len; |
e6811d1d LD |
1879 | if (!xfer->bits_per_word) |
1880 | xfer->bits_per_word = spi->bits_per_word; | |
a6f87fad AL |
1881 | |
1882 | if (!xfer->speed_hz) | |
059b8ffe | 1883 | xfer->speed_hz = spi->max_speed_hz; |
a6f87fad AL |
1884 | |
1885 | if (master->max_speed_hz && | |
1886 | xfer->speed_hz > master->max_speed_hz) | |
1887 | xfer->speed_hz = master->max_speed_hz; | |
56ede94a | 1888 | |
543bb255 SW |
1889 | if (master->bits_per_word_mask) { |
1890 | /* Only 32 bits fit in the mask */ | |
1891 | if (xfer->bits_per_word > 32) | |
1892 | return -EINVAL; | |
1893 | if (!(master->bits_per_word_mask & | |
1894 | BIT(xfer->bits_per_word - 1))) | |
1895 | return -EINVAL; | |
1896 | } | |
a2fd4f9f | 1897 | |
4d94bd21 II |
1898 | /* |
1899 | * SPI transfer length should be multiple of SPI word size | |
1900 | * where SPI word size should be power-of-two multiple | |
1901 | */ | |
1902 | if (xfer->bits_per_word <= 8) | |
1903 | w_size = 1; | |
1904 | else if (xfer->bits_per_word <= 16) | |
1905 | w_size = 2; | |
1906 | else | |
1907 | w_size = 4; | |
1908 | ||
4d94bd21 | 1909 | /* No partial transfers accepted */ |
6ea31293 | 1910 | if (xfer->len % w_size) |
4d94bd21 II |
1911 | return -EINVAL; |
1912 | ||
a2fd4f9f MB |
1913 | if (xfer->speed_hz && master->min_speed_hz && |
1914 | xfer->speed_hz < master->min_speed_hz) | |
1915 | return -EINVAL; | |
f477b7fb | 1916 | |
1917 | if (xfer->tx_buf && !xfer->tx_nbits) | |
1918 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
1919 | if (xfer->rx_buf && !xfer->rx_nbits) | |
1920 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
1921 | /* check transfer tx/rx_nbits: | |
1afd9989 GU |
1922 | * 1. check the value matches one of single, dual and quad |
1923 | * 2. check tx/rx_nbits match the mode in spi_device | |
f477b7fb | 1924 | */ |
db90a441 SP |
1925 | if (xfer->tx_buf) { |
1926 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
1927 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
1928 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
1929 | return -EINVAL; | |
1930 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
1931 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
1932 | return -EINVAL; | |
1933 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
1934 | !(spi->mode & SPI_TX_QUAD)) | |
1935 | return -EINVAL; | |
db90a441 | 1936 | } |
f477b7fb | 1937 | /* check transfer rx_nbits */ |
db90a441 SP |
1938 | if (xfer->rx_buf) { |
1939 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
1940 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
1941 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
1942 | return -EINVAL; | |
1943 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
1944 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
1945 | return -EINVAL; | |
1946 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
1947 | !(spi->mode & SPI_RX_QUAD)) | |
1948 | return -EINVAL; | |
db90a441 | 1949 | } |
e6811d1d LD |
1950 | } |
1951 | ||
cf32b71e | 1952 | message->status = -EINPROGRESS; |
90808738 MB |
1953 | |
1954 | return 0; | |
1955 | } | |
1956 | ||
1957 | static int __spi_async(struct spi_device *spi, struct spi_message *message) | |
1958 | { | |
1959 | struct spi_master *master = spi->master; | |
1960 | ||
1961 | message->spi = spi; | |
1962 | ||
1963 | trace_spi_message_submit(message); | |
1964 | ||
cf32b71e ES |
1965 | return master->transfer(spi, message); |
1966 | } | |
1967 | ||
568d0697 DB |
1968 | /** |
1969 | * spi_async - asynchronous SPI transfer | |
1970 | * @spi: device with which data will be exchanged | |
1971 | * @message: describes the data transfers, including completion callback | |
1972 | * Context: any (irqs may be blocked, etc) | |
1973 | * | |
1974 | * This call may be used in_irq and other contexts which can't sleep, | |
1975 | * as well as from task contexts which can sleep. | |
1976 | * | |
1977 | * The completion callback is invoked in a context which can't sleep. | |
1978 | * Before that invocation, the value of message->status is undefined. | |
1979 | * When the callback is issued, message->status holds either zero (to | |
1980 | * indicate complete success) or a negative error code. After that | |
1981 | * callback returns, the driver which issued the transfer request may | |
1982 | * deallocate the associated memory; it's no longer in use by any SPI | |
1983 | * core or controller driver code. | |
1984 | * | |
1985 | * Note that although all messages to a spi_device are handled in | |
1986 | * FIFO order, messages may go to different devices in other orders. | |
1987 | * Some device might be higher priority, or have various "hard" access | |
1988 | * time requirements, for example. | |
1989 | * | |
1990 | * On detection of any fault during the transfer, processing of | |
1991 | * the entire message is aborted, and the device is deselected. | |
1992 | * Until returning from the associated message completion callback, | |
1993 | * no other spi_message queued to that device will be processed. | |
1994 | * (This rule applies equally to all the synchronous transfer calls, | |
1995 | * which are wrappers around this core asynchronous primitive.) | |
1996 | */ | |
1997 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
1998 | { | |
1999 | struct spi_master *master = spi->master; | |
cf32b71e ES |
2000 | int ret; |
2001 | unsigned long flags; | |
568d0697 | 2002 | |
90808738 MB |
2003 | ret = __spi_validate(spi, message); |
2004 | if (ret != 0) | |
2005 | return ret; | |
2006 | ||
cf32b71e | 2007 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 2008 | |
cf32b71e ES |
2009 | if (master->bus_lock_flag) |
2010 | ret = -EBUSY; | |
2011 | else | |
2012 | ret = __spi_async(spi, message); | |
568d0697 | 2013 | |
cf32b71e ES |
2014 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
2015 | ||
2016 | return ret; | |
568d0697 DB |
2017 | } |
2018 | EXPORT_SYMBOL_GPL(spi_async); | |
2019 | ||
cf32b71e ES |
2020 | /** |
2021 | * spi_async_locked - version of spi_async with exclusive bus usage | |
2022 | * @spi: device with which data will be exchanged | |
2023 | * @message: describes the data transfers, including completion callback | |
2024 | * Context: any (irqs may be blocked, etc) | |
2025 | * | |
2026 | * This call may be used in_irq and other contexts which can't sleep, | |
2027 | * as well as from task contexts which can sleep. | |
2028 | * | |
2029 | * The completion callback is invoked in a context which can't sleep. | |
2030 | * Before that invocation, the value of message->status is undefined. | |
2031 | * When the callback is issued, message->status holds either zero (to | |
2032 | * indicate complete success) or a negative error code. After that | |
2033 | * callback returns, the driver which issued the transfer request may | |
2034 | * deallocate the associated memory; it's no longer in use by any SPI | |
2035 | * core or controller driver code. | |
2036 | * | |
2037 | * Note that although all messages to a spi_device are handled in | |
2038 | * FIFO order, messages may go to different devices in other orders. | |
2039 | * Some device might be higher priority, or have various "hard" access | |
2040 | * time requirements, for example. | |
2041 | * | |
2042 | * On detection of any fault during the transfer, processing of | |
2043 | * the entire message is aborted, and the device is deselected. | |
2044 | * Until returning from the associated message completion callback, | |
2045 | * no other spi_message queued to that device will be processed. | |
2046 | * (This rule applies equally to all the synchronous transfer calls, | |
2047 | * which are wrappers around this core asynchronous primitive.) | |
2048 | */ | |
2049 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
2050 | { | |
2051 | struct spi_master *master = spi->master; | |
2052 | int ret; | |
2053 | unsigned long flags; | |
2054 | ||
90808738 MB |
2055 | ret = __spi_validate(spi, message); |
2056 | if (ret != 0) | |
2057 | return ret; | |
2058 | ||
cf32b71e ES |
2059 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
2060 | ||
2061 | ret = __spi_async(spi, message); | |
2062 | ||
2063 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2064 | ||
2065 | return ret; | |
2066 | ||
2067 | } | |
2068 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
2069 | ||
7d077197 DB |
2070 | |
2071 | /*-------------------------------------------------------------------------*/ | |
2072 | ||
2073 | /* Utility methods for SPI master protocol drivers, layered on | |
2074 | * top of the core. Some other utility methods are defined as | |
2075 | * inline functions. | |
2076 | */ | |
2077 | ||
5d870c8e AM |
2078 | static void spi_complete(void *arg) |
2079 | { | |
2080 | complete(arg); | |
2081 | } | |
2082 | ||
cf32b71e ES |
2083 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
2084 | int bus_locked) | |
2085 | { | |
2086 | DECLARE_COMPLETION_ONSTACK(done); | |
2087 | int status; | |
2088 | struct spi_master *master = spi->master; | |
2089 | ||
2090 | message->complete = spi_complete; | |
2091 | message->context = &done; | |
2092 | ||
2093 | if (!bus_locked) | |
2094 | mutex_lock(&master->bus_lock_mutex); | |
2095 | ||
2096 | status = spi_async_locked(spi, message); | |
2097 | ||
2098 | if (!bus_locked) | |
2099 | mutex_unlock(&master->bus_lock_mutex); | |
2100 | ||
2101 | if (status == 0) { | |
2102 | wait_for_completion(&done); | |
2103 | status = message->status; | |
2104 | } | |
2105 | message->context = NULL; | |
2106 | return status; | |
2107 | } | |
2108 | ||
8ae12a0d DB |
2109 | /** |
2110 | * spi_sync - blocking/synchronous SPI data transfers | |
2111 | * @spi: device with which data will be exchanged | |
2112 | * @message: describes the data transfers | |
33e34dc6 | 2113 | * Context: can sleep |
8ae12a0d DB |
2114 | * |
2115 | * This call may only be used from a context that may sleep. The sleep | |
2116 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2117 | * drivers may DMA directly into and out of the message buffers. | |
2118 | * | |
2119 | * Note that the SPI device's chip select is active during the message, | |
2120 | * and then is normally disabled between messages. Drivers for some | |
2121 | * frequently-used devices may want to minimize costs of selecting a chip, | |
2122 | * by leaving it selected in anticipation that the next message will go | |
2123 | * to the same chip. (That may increase power usage.) | |
2124 | * | |
0c868461 DB |
2125 | * Also, the caller is guaranteeing that the memory associated with the |
2126 | * message will not be freed before this call returns. | |
2127 | * | |
9b938b74 | 2128 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
2129 | */ |
2130 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
2131 | { | |
cf32b71e | 2132 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
2133 | } |
2134 | EXPORT_SYMBOL_GPL(spi_sync); | |
2135 | ||
cf32b71e ES |
2136 | /** |
2137 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
2138 | * @spi: device with which data will be exchanged | |
2139 | * @message: describes the data transfers | |
2140 | * Context: can sleep | |
2141 | * | |
2142 | * This call may only be used from a context that may sleep. The sleep | |
2143 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2144 | * drivers may DMA directly into and out of the message buffers. | |
2145 | * | |
2146 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 2147 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
2148 | * be released by a spi_bus_unlock call when the exclusive access is over. |
2149 | * | |
2150 | * It returns zero on success, else a negative error code. | |
2151 | */ | |
2152 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
2153 | { | |
2154 | return __spi_sync(spi, message, 1); | |
2155 | } | |
2156 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
2157 | ||
2158 | /** | |
2159 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
2160 | * @master: SPI bus master that should be locked for exclusive bus access | |
2161 | * Context: can sleep | |
2162 | * | |
2163 | * This call may only be used from a context that may sleep. The sleep | |
2164 | * is non-interruptible, and has no timeout. | |
2165 | * | |
2166 | * This call should be used by drivers that require exclusive access to the | |
2167 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
2168 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
2169 | * and spi_async_locked calls when the SPI bus lock is held. | |
2170 | * | |
2171 | * It returns zero on success, else a negative error code. | |
2172 | */ | |
2173 | int spi_bus_lock(struct spi_master *master) | |
2174 | { | |
2175 | unsigned long flags; | |
2176 | ||
2177 | mutex_lock(&master->bus_lock_mutex); | |
2178 | ||
2179 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2180 | master->bus_lock_flag = 1; | |
2181 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2182 | ||
2183 | /* mutex remains locked until spi_bus_unlock is called */ | |
2184 | ||
2185 | return 0; | |
2186 | } | |
2187 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
2188 | ||
2189 | /** | |
2190 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
2191 | * @master: SPI bus master that was locked for exclusive bus access | |
2192 | * Context: can sleep | |
2193 | * | |
2194 | * This call may only be used from a context that may sleep. The sleep | |
2195 | * is non-interruptible, and has no timeout. | |
2196 | * | |
2197 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
2198 | * call. | |
2199 | * | |
2200 | * It returns zero on success, else a negative error code. | |
2201 | */ | |
2202 | int spi_bus_unlock(struct spi_master *master) | |
2203 | { | |
2204 | master->bus_lock_flag = 0; | |
2205 | ||
2206 | mutex_unlock(&master->bus_lock_mutex); | |
2207 | ||
2208 | return 0; | |
2209 | } | |
2210 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
2211 | ||
a9948b61 | 2212 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 2213 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
2214 | |
2215 | static u8 *buf; | |
2216 | ||
2217 | /** | |
2218 | * spi_write_then_read - SPI synchronous write followed by read | |
2219 | * @spi: device with which data will be exchanged | |
2220 | * @txbuf: data to be written (need not be dma-safe) | |
2221 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
2222 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
2223 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 2224 | * Context: can sleep |
8ae12a0d DB |
2225 | * |
2226 | * This performs a half duplex MicroWire style transaction with the | |
2227 | * device, sending txbuf and then reading rxbuf. The return value | |
2228 | * is zero for success, else a negative errno status code. | |
b885244e | 2229 | * This call may only be used from a context that may sleep. |
8ae12a0d | 2230 | * |
0c868461 | 2231 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
2232 | * portable code should never use this for more than 32 bytes. |
2233 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 2234 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
2235 | */ |
2236 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
2237 | const void *txbuf, unsigned n_tx, |
2238 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 2239 | { |
068f4070 | 2240 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
2241 | |
2242 | int status; | |
2243 | struct spi_message message; | |
bdff549e | 2244 | struct spi_transfer x[2]; |
8ae12a0d DB |
2245 | u8 *local_buf; |
2246 | ||
b3a223ee MB |
2247 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
2248 | * copying here, (as a pure convenience thing), but we can | |
2249 | * keep heap costs out of the hot path unless someone else is | |
2250 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 2251 | */ |
b3a223ee | 2252 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
2253 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
2254 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
2255 | if (!local_buf) |
2256 | return -ENOMEM; | |
2257 | } else { | |
2258 | local_buf = buf; | |
2259 | } | |
8ae12a0d | 2260 | |
8275c642 | 2261 | spi_message_init(&message); |
5fe5f05e | 2262 | memset(x, 0, sizeof(x)); |
bdff549e DB |
2263 | if (n_tx) { |
2264 | x[0].len = n_tx; | |
2265 | spi_message_add_tail(&x[0], &message); | |
2266 | } | |
2267 | if (n_rx) { | |
2268 | x[1].len = n_rx; | |
2269 | spi_message_add_tail(&x[1], &message); | |
2270 | } | |
8275c642 | 2271 | |
8ae12a0d | 2272 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2273 | x[0].tx_buf = local_buf; |
2274 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2275 | |
2276 | /* do the i/o */ | |
8ae12a0d | 2277 | status = spi_sync(spi, &message); |
9b938b74 | 2278 | if (status == 0) |
bdff549e | 2279 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2280 | |
bdff549e | 2281 | if (x[0].tx_buf == buf) |
068f4070 | 2282 | mutex_unlock(&lock); |
8ae12a0d DB |
2283 | else |
2284 | kfree(local_buf); | |
2285 | ||
2286 | return status; | |
2287 | } | |
2288 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2289 | ||
2290 | /*-------------------------------------------------------------------------*/ | |
2291 | ||
2292 | static int __init spi_init(void) | |
2293 | { | |
b885244e DB |
2294 | int status; |
2295 | ||
e94b1766 | 2296 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2297 | if (!buf) { |
2298 | status = -ENOMEM; | |
2299 | goto err0; | |
2300 | } | |
2301 | ||
2302 | status = bus_register(&spi_bus_type); | |
2303 | if (status < 0) | |
2304 | goto err1; | |
8ae12a0d | 2305 | |
b885244e DB |
2306 | status = class_register(&spi_master_class); |
2307 | if (status < 0) | |
2308 | goto err2; | |
8ae12a0d | 2309 | return 0; |
b885244e DB |
2310 | |
2311 | err2: | |
2312 | bus_unregister(&spi_bus_type); | |
2313 | err1: | |
2314 | kfree(buf); | |
2315 | buf = NULL; | |
2316 | err0: | |
2317 | return status; | |
8ae12a0d | 2318 | } |
b885244e | 2319 | |
8ae12a0d DB |
2320 | /* board_info is normally registered in arch_initcall(), |
2321 | * but even essential drivers wait till later | |
b885244e DB |
2322 | * |
2323 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2324 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2325 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2326 | */ |
673c0c00 | 2327 | postcore_initcall(spi_init); |
8ae12a0d | 2328 |