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. | |
8ae12a0d DB |
16 | */ |
17 | ||
8ae12a0d DB |
18 | #include <linux/kernel.h> |
19 | #include <linux/device.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/cache.h> | |
99adef31 MB |
22 | #include <linux/dma-mapping.h> |
23 | #include <linux/dmaengine.h> | |
94040828 | 24 | #include <linux/mutex.h> |
2b7a32f7 | 25 | #include <linux/of_device.h> |
d57a4282 | 26 | #include <linux/of_irq.h> |
86be408b | 27 | #include <linux/clk/clk-conf.h> |
5a0e3ad6 | 28 | #include <linux/slab.h> |
e0626e38 | 29 | #include <linux/mod_devicetable.h> |
8ae12a0d | 30 | #include <linux/spi/spi.h> |
74317984 | 31 | #include <linux/of_gpio.h> |
3ae22e8c | 32 | #include <linux/pm_runtime.h> |
f48c767c | 33 | #include <linux/pm_domain.h> |
025ed130 | 34 | #include <linux/export.h> |
8bd75c77 | 35 | #include <linux/sched/rt.h> |
ffbbdd21 LW |
36 | #include <linux/delay.h> |
37 | #include <linux/kthread.h> | |
64bee4d2 MW |
38 | #include <linux/ioport.h> |
39 | #include <linux/acpi.h> | |
8ae12a0d | 40 | |
56ec1978 MB |
41 | #define CREATE_TRACE_POINTS |
42 | #include <trace/events/spi.h> | |
43 | ||
8ae12a0d DB |
44 | static void spidev_release(struct device *dev) |
45 | { | |
0ffa0285 | 46 | struct spi_device *spi = to_spi_device(dev); |
8ae12a0d DB |
47 | |
48 | /* spi masters may cleanup for released devices */ | |
49 | if (spi->master->cleanup) | |
50 | spi->master->cleanup(spi); | |
51 | ||
0c868461 | 52 | spi_master_put(spi->master); |
07a389fe | 53 | kfree(spi); |
8ae12a0d DB |
54 | } |
55 | ||
56 | static ssize_t | |
57 | modalias_show(struct device *dev, struct device_attribute *a, char *buf) | |
58 | { | |
59 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
60 | int len; |
61 | ||
62 | len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1); | |
63 | if (len != -ENODEV) | |
64 | return len; | |
8ae12a0d | 65 | |
d8e328b3 | 66 | return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d | 67 | } |
aa7da564 | 68 | static DEVICE_ATTR_RO(modalias); |
8ae12a0d | 69 | |
aa7da564 GKH |
70 | static struct attribute *spi_dev_attrs[] = { |
71 | &dev_attr_modalias.attr, | |
72 | NULL, | |
8ae12a0d | 73 | }; |
aa7da564 | 74 | ATTRIBUTE_GROUPS(spi_dev); |
8ae12a0d DB |
75 | |
76 | /* modalias support makes "modprobe $MODALIAS" new-style hotplug work, | |
77 | * and the sysfs version makes coldplug work too. | |
78 | */ | |
79 | ||
75368bf6 AV |
80 | static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, |
81 | const struct spi_device *sdev) | |
82 | { | |
83 | while (id->name[0]) { | |
84 | if (!strcmp(sdev->modalias, id->name)) | |
85 | return id; | |
86 | id++; | |
87 | } | |
88 | return NULL; | |
89 | } | |
90 | ||
91 | const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev) | |
92 | { | |
93 | const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver); | |
94 | ||
95 | return spi_match_id(sdrv->id_table, sdev); | |
96 | } | |
97 | EXPORT_SYMBOL_GPL(spi_get_device_id); | |
98 | ||
8ae12a0d DB |
99 | static int spi_match_device(struct device *dev, struct device_driver *drv) |
100 | { | |
101 | const struct spi_device *spi = to_spi_device(dev); | |
75368bf6 AV |
102 | const struct spi_driver *sdrv = to_spi_driver(drv); |
103 | ||
2b7a32f7 SA |
104 | /* Attempt an OF style match */ |
105 | if (of_driver_match_device(dev, drv)) | |
106 | return 1; | |
107 | ||
64bee4d2 MW |
108 | /* Then try ACPI */ |
109 | if (acpi_driver_match_device(dev, drv)) | |
110 | return 1; | |
111 | ||
75368bf6 AV |
112 | if (sdrv->id_table) |
113 | return !!spi_match_id(sdrv->id_table, spi); | |
8ae12a0d | 114 | |
35f74fca | 115 | return strcmp(spi->modalias, drv->name) == 0; |
8ae12a0d DB |
116 | } |
117 | ||
7eff2e7a | 118 | static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) |
8ae12a0d DB |
119 | { |
120 | const struct spi_device *spi = to_spi_device(dev); | |
8c4ff6d0 ZR |
121 | int rc; |
122 | ||
123 | rc = acpi_device_uevent_modalias(dev, env); | |
124 | if (rc != -ENODEV) | |
125 | return rc; | |
8ae12a0d | 126 | |
e0626e38 | 127 | add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); |
8ae12a0d DB |
128 | return 0; |
129 | } | |
130 | ||
8ae12a0d DB |
131 | struct bus_type spi_bus_type = { |
132 | .name = "spi", | |
aa7da564 | 133 | .dev_groups = spi_dev_groups, |
8ae12a0d DB |
134 | .match = spi_match_device, |
135 | .uevent = spi_uevent, | |
8ae12a0d DB |
136 | }; |
137 | EXPORT_SYMBOL_GPL(spi_bus_type); | |
138 | ||
b885244e DB |
139 | |
140 | static int spi_drv_probe(struct device *dev) | |
141 | { | |
142 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
143 | int ret; |
144 | ||
86be408b SN |
145 | ret = of_clk_set_defaults(dev->of_node, false); |
146 | if (ret) | |
147 | return ret; | |
148 | ||
676e7c25 UH |
149 | ret = dev_pm_domain_attach(dev, true); |
150 | if (ret != -EPROBE_DEFER) { | |
151 | ret = sdrv->probe(to_spi_device(dev)); | |
152 | if (ret) | |
153 | dev_pm_domain_detach(dev, true); | |
154 | } | |
b885244e | 155 | |
33cf00e5 | 156 | return ret; |
b885244e DB |
157 | } |
158 | ||
159 | static int spi_drv_remove(struct device *dev) | |
160 | { | |
161 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
33cf00e5 MW |
162 | int ret; |
163 | ||
aec35f4e | 164 | ret = sdrv->remove(to_spi_device(dev)); |
676e7c25 | 165 | dev_pm_domain_detach(dev, true); |
b885244e | 166 | |
33cf00e5 | 167 | return ret; |
b885244e DB |
168 | } |
169 | ||
170 | static void spi_drv_shutdown(struct device *dev) | |
171 | { | |
172 | const struct spi_driver *sdrv = to_spi_driver(dev->driver); | |
173 | ||
174 | sdrv->shutdown(to_spi_device(dev)); | |
175 | } | |
176 | ||
33e34dc6 DB |
177 | /** |
178 | * spi_register_driver - register a SPI driver | |
179 | * @sdrv: the driver to register | |
180 | * Context: can sleep | |
181 | */ | |
b885244e DB |
182 | int spi_register_driver(struct spi_driver *sdrv) |
183 | { | |
184 | sdrv->driver.bus = &spi_bus_type; | |
185 | if (sdrv->probe) | |
186 | sdrv->driver.probe = spi_drv_probe; | |
187 | if (sdrv->remove) | |
188 | sdrv->driver.remove = spi_drv_remove; | |
189 | if (sdrv->shutdown) | |
190 | sdrv->driver.shutdown = spi_drv_shutdown; | |
191 | return driver_register(&sdrv->driver); | |
192 | } | |
193 | EXPORT_SYMBOL_GPL(spi_register_driver); | |
194 | ||
8ae12a0d DB |
195 | /*-------------------------------------------------------------------------*/ |
196 | ||
197 | /* SPI devices should normally not be created by SPI device drivers; that | |
198 | * would make them board-specific. Similarly with SPI master drivers. | |
199 | * Device registration normally goes into like arch/.../mach.../board-YYY.c | |
200 | * with other readonly (flashable) information about mainboard devices. | |
201 | */ | |
202 | ||
203 | struct boardinfo { | |
204 | struct list_head list; | |
2b9603a0 | 205 | struct spi_board_info board_info; |
8ae12a0d DB |
206 | }; |
207 | ||
208 | static LIST_HEAD(board_list); | |
2b9603a0 FT |
209 | static LIST_HEAD(spi_master_list); |
210 | ||
211 | /* | |
212 | * Used to protect add/del opertion for board_info list and | |
213 | * spi_master list, and their matching process | |
214 | */ | |
94040828 | 215 | static DEFINE_MUTEX(board_lock); |
8ae12a0d | 216 | |
dc87c98e GL |
217 | /** |
218 | * spi_alloc_device - Allocate a new SPI device | |
219 | * @master: Controller to which device is connected | |
220 | * Context: can sleep | |
221 | * | |
222 | * Allows a driver to allocate and initialize a spi_device without | |
223 | * registering it immediately. This allows a driver to directly | |
224 | * fill the spi_device with device parameters before calling | |
225 | * spi_add_device() on it. | |
226 | * | |
227 | * Caller is responsible to call spi_add_device() on the returned | |
228 | * spi_device structure to add it to the SPI master. If the caller | |
229 | * needs to discard the spi_device without adding it, then it should | |
230 | * call spi_dev_put() on it. | |
231 | * | |
232 | * Returns a pointer to the new device, or NULL. | |
233 | */ | |
234 | struct spi_device *spi_alloc_device(struct spi_master *master) | |
235 | { | |
236 | struct spi_device *spi; | |
dc87c98e GL |
237 | |
238 | if (!spi_master_get(master)) | |
239 | return NULL; | |
240 | ||
5fe5f05e | 241 | spi = kzalloc(sizeof(*spi), GFP_KERNEL); |
dc87c98e | 242 | if (!spi) { |
dc87c98e GL |
243 | spi_master_put(master); |
244 | return NULL; | |
245 | } | |
246 | ||
247 | spi->master = master; | |
178db7d3 | 248 | spi->dev.parent = &master->dev; |
dc87c98e GL |
249 | spi->dev.bus = &spi_bus_type; |
250 | spi->dev.release = spidev_release; | |
446411e1 | 251 | spi->cs_gpio = -ENOENT; |
dc87c98e GL |
252 | device_initialize(&spi->dev); |
253 | return spi; | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(spi_alloc_device); | |
256 | ||
e13ac47b JN |
257 | static void spi_dev_set_name(struct spi_device *spi) |
258 | { | |
259 | struct acpi_device *adev = ACPI_COMPANION(&spi->dev); | |
260 | ||
261 | if (adev) { | |
262 | dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev)); | |
263 | return; | |
264 | } | |
265 | ||
266 | dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), | |
267 | spi->chip_select); | |
268 | } | |
269 | ||
b6fb8d3a MW |
270 | static int spi_dev_check(struct device *dev, void *data) |
271 | { | |
272 | struct spi_device *spi = to_spi_device(dev); | |
273 | struct spi_device *new_spi = data; | |
274 | ||
275 | if (spi->master == new_spi->master && | |
276 | spi->chip_select == new_spi->chip_select) | |
277 | return -EBUSY; | |
278 | return 0; | |
279 | } | |
280 | ||
dc87c98e GL |
281 | /** |
282 | * spi_add_device - Add spi_device allocated with spi_alloc_device | |
283 | * @spi: spi_device to register | |
284 | * | |
285 | * Companion function to spi_alloc_device. Devices allocated with | |
286 | * spi_alloc_device can be added onto the spi bus with this function. | |
287 | * | |
e48880e0 | 288 | * Returns 0 on success; negative errno on failure |
dc87c98e GL |
289 | */ |
290 | int spi_add_device(struct spi_device *spi) | |
291 | { | |
e48880e0 | 292 | static DEFINE_MUTEX(spi_add_lock); |
74317984 JCPV |
293 | struct spi_master *master = spi->master; |
294 | struct device *dev = master->dev.parent; | |
dc87c98e GL |
295 | int status; |
296 | ||
297 | /* Chipselects are numbered 0..max; validate. */ | |
74317984 | 298 | if (spi->chip_select >= master->num_chipselect) { |
dc87c98e GL |
299 | dev_err(dev, "cs%d >= max %d\n", |
300 | spi->chip_select, | |
74317984 | 301 | master->num_chipselect); |
dc87c98e GL |
302 | return -EINVAL; |
303 | } | |
304 | ||
305 | /* Set the bus ID string */ | |
e13ac47b | 306 | spi_dev_set_name(spi); |
e48880e0 DB |
307 | |
308 | /* We need to make sure there's no other device with this | |
309 | * chipselect **BEFORE** we call setup(), else we'll trash | |
310 | * its configuration. Lock against concurrent add() calls. | |
311 | */ | |
312 | mutex_lock(&spi_add_lock); | |
313 | ||
b6fb8d3a MW |
314 | status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); |
315 | if (status) { | |
e48880e0 DB |
316 | dev_err(dev, "chipselect %d already in use\n", |
317 | spi->chip_select); | |
e48880e0 DB |
318 | goto done; |
319 | } | |
320 | ||
74317984 JCPV |
321 | if (master->cs_gpios) |
322 | spi->cs_gpio = master->cs_gpios[spi->chip_select]; | |
323 | ||
e48880e0 DB |
324 | /* Drivers may modify this initial i/o setup, but will |
325 | * normally rely on the device being setup. Devices | |
326 | * using SPI_CS_HIGH can't coexist well otherwise... | |
327 | */ | |
7d077197 | 328 | status = spi_setup(spi); |
dc87c98e | 329 | if (status < 0) { |
eb288a1f LW |
330 | dev_err(dev, "can't setup %s, status %d\n", |
331 | dev_name(&spi->dev), status); | |
e48880e0 | 332 | goto done; |
dc87c98e GL |
333 | } |
334 | ||
e48880e0 | 335 | /* Device may be bound to an active driver when this returns */ |
dc87c98e | 336 | status = device_add(&spi->dev); |
e48880e0 | 337 | if (status < 0) |
eb288a1f LW |
338 | dev_err(dev, "can't add %s, status %d\n", |
339 | dev_name(&spi->dev), status); | |
e48880e0 | 340 | else |
35f74fca | 341 | dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); |
dc87c98e | 342 | |
e48880e0 DB |
343 | done: |
344 | mutex_unlock(&spi_add_lock); | |
345 | return status; | |
dc87c98e GL |
346 | } |
347 | EXPORT_SYMBOL_GPL(spi_add_device); | |
8ae12a0d | 348 | |
33e34dc6 DB |
349 | /** |
350 | * spi_new_device - instantiate one new SPI device | |
351 | * @master: Controller to which device is connected | |
352 | * @chip: Describes the SPI device | |
353 | * Context: can sleep | |
354 | * | |
355 | * On typical mainboards, this is purely internal; and it's not needed | |
8ae12a0d DB |
356 | * after board init creates the hard-wired devices. Some development |
357 | * platforms may not be able to use spi_register_board_info though, and | |
358 | * this is exported so that for example a USB or parport based adapter | |
359 | * driver could add devices (which it would learn about out-of-band). | |
082c8cb4 DB |
360 | * |
361 | * Returns the new device, or NULL. | |
8ae12a0d | 362 | */ |
e9d5a461 AB |
363 | struct spi_device *spi_new_device(struct spi_master *master, |
364 | struct spi_board_info *chip) | |
8ae12a0d DB |
365 | { |
366 | struct spi_device *proxy; | |
8ae12a0d DB |
367 | int status; |
368 | ||
082c8cb4 DB |
369 | /* NOTE: caller did any chip->bus_num checks necessary. |
370 | * | |
371 | * Also, unless we change the return value convention to use | |
372 | * error-or-pointer (not NULL-or-pointer), troubleshootability | |
373 | * suggests syslogged diagnostics are best here (ugh). | |
374 | */ | |
375 | ||
dc87c98e GL |
376 | proxy = spi_alloc_device(master); |
377 | if (!proxy) | |
8ae12a0d DB |
378 | return NULL; |
379 | ||
102eb975 GL |
380 | WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); |
381 | ||
8ae12a0d DB |
382 | proxy->chip_select = chip->chip_select; |
383 | proxy->max_speed_hz = chip->max_speed_hz; | |
980a01c9 | 384 | proxy->mode = chip->mode; |
8ae12a0d | 385 | proxy->irq = chip->irq; |
102eb975 | 386 | strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); |
8ae12a0d DB |
387 | proxy->dev.platform_data = (void *) chip->platform_data; |
388 | proxy->controller_data = chip->controller_data; | |
389 | proxy->controller_state = NULL; | |
8ae12a0d | 390 | |
dc87c98e | 391 | status = spi_add_device(proxy); |
8ae12a0d | 392 | if (status < 0) { |
dc87c98e GL |
393 | spi_dev_put(proxy); |
394 | return NULL; | |
8ae12a0d DB |
395 | } |
396 | ||
8ae12a0d DB |
397 | return proxy; |
398 | } | |
399 | EXPORT_SYMBOL_GPL(spi_new_device); | |
400 | ||
2b9603a0 FT |
401 | static void spi_match_master_to_boardinfo(struct spi_master *master, |
402 | struct spi_board_info *bi) | |
403 | { | |
404 | struct spi_device *dev; | |
405 | ||
406 | if (master->bus_num != bi->bus_num) | |
407 | return; | |
408 | ||
409 | dev = spi_new_device(master, bi); | |
410 | if (!dev) | |
411 | dev_err(master->dev.parent, "can't create new device for %s\n", | |
412 | bi->modalias); | |
413 | } | |
414 | ||
33e34dc6 DB |
415 | /** |
416 | * spi_register_board_info - register SPI devices for a given board | |
417 | * @info: array of chip descriptors | |
418 | * @n: how many descriptors are provided | |
419 | * Context: can sleep | |
420 | * | |
8ae12a0d DB |
421 | * Board-specific early init code calls this (probably during arch_initcall) |
422 | * with segments of the SPI device table. Any device nodes are created later, | |
423 | * after the relevant parent SPI controller (bus_num) is defined. We keep | |
424 | * this table of devices forever, so that reloading a controller driver will | |
425 | * not make Linux forget about these hard-wired devices. | |
426 | * | |
427 | * Other code can also call this, e.g. a particular add-on board might provide | |
428 | * SPI devices through its expansion connector, so code initializing that board | |
429 | * would naturally declare its SPI devices. | |
430 | * | |
431 | * The board info passed can safely be __initdata ... but be careful of | |
432 | * any embedded pointers (platform_data, etc), they're copied as-is. | |
433 | */ | |
fd4a319b | 434 | int spi_register_board_info(struct spi_board_info const *info, unsigned n) |
8ae12a0d | 435 | { |
2b9603a0 FT |
436 | struct boardinfo *bi; |
437 | int i; | |
8ae12a0d | 438 | |
c7908a37 XL |
439 | if (!n) |
440 | return -EINVAL; | |
441 | ||
2b9603a0 | 442 | bi = kzalloc(n * sizeof(*bi), GFP_KERNEL); |
8ae12a0d DB |
443 | if (!bi) |
444 | return -ENOMEM; | |
8ae12a0d | 445 | |
2b9603a0 FT |
446 | for (i = 0; i < n; i++, bi++, info++) { |
447 | struct spi_master *master; | |
8ae12a0d | 448 | |
2b9603a0 FT |
449 | memcpy(&bi->board_info, info, sizeof(*info)); |
450 | mutex_lock(&board_lock); | |
451 | list_add_tail(&bi->list, &board_list); | |
452 | list_for_each_entry(master, &spi_master_list, list) | |
453 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
454 | mutex_unlock(&board_lock); | |
8ae12a0d | 455 | } |
2b9603a0 FT |
456 | |
457 | return 0; | |
8ae12a0d DB |
458 | } |
459 | ||
460 | /*-------------------------------------------------------------------------*/ | |
461 | ||
b158935f MB |
462 | static void spi_set_cs(struct spi_device *spi, bool enable) |
463 | { | |
464 | if (spi->mode & SPI_CS_HIGH) | |
465 | enable = !enable; | |
466 | ||
467 | if (spi->cs_gpio >= 0) | |
468 | gpio_set_value(spi->cs_gpio, !enable); | |
469 | else if (spi->master->set_cs) | |
470 | spi->master->set_cs(spi, !enable); | |
471 | } | |
472 | ||
2de440f5 | 473 | #ifdef CONFIG_HAS_DMA |
6ad45a27 MB |
474 | static int spi_map_buf(struct spi_master *master, struct device *dev, |
475 | struct sg_table *sgt, void *buf, size_t len, | |
476 | enum dma_data_direction dir) | |
477 | { | |
478 | const bool vmalloced_buf = is_vmalloc_addr(buf); | |
479 | const int desc_len = vmalloced_buf ? PAGE_SIZE : master->max_dma_len; | |
480 | const int sgs = DIV_ROUND_UP(len, desc_len); | |
481 | struct page *vm_page; | |
482 | void *sg_buf; | |
483 | size_t min; | |
484 | int i, ret; | |
485 | ||
486 | ret = sg_alloc_table(sgt, sgs, GFP_KERNEL); | |
487 | if (ret != 0) | |
488 | return ret; | |
489 | ||
490 | for (i = 0; i < sgs; i++) { | |
491 | min = min_t(size_t, len, desc_len); | |
492 | ||
493 | if (vmalloced_buf) { | |
494 | vm_page = vmalloc_to_page(buf); | |
495 | if (!vm_page) { | |
496 | sg_free_table(sgt); | |
497 | return -ENOMEM; | |
498 | } | |
c1aefbdd CK |
499 | sg_set_page(&sgt->sgl[i], vm_page, |
500 | min, offset_in_page(buf)); | |
6ad45a27 MB |
501 | } else { |
502 | sg_buf = buf; | |
c1aefbdd | 503 | sg_set_buf(&sgt->sgl[i], sg_buf, min); |
6ad45a27 MB |
504 | } |
505 | ||
6ad45a27 MB |
506 | |
507 | buf += min; | |
508 | len -= min; | |
509 | } | |
510 | ||
511 | ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir); | |
89e4b66a GU |
512 | if (!ret) |
513 | ret = -ENOMEM; | |
6ad45a27 MB |
514 | if (ret < 0) { |
515 | sg_free_table(sgt); | |
516 | return ret; | |
517 | } | |
518 | ||
519 | sgt->nents = ret; | |
520 | ||
521 | return 0; | |
522 | } | |
523 | ||
524 | static void spi_unmap_buf(struct spi_master *master, struct device *dev, | |
525 | struct sg_table *sgt, enum dma_data_direction dir) | |
526 | { | |
527 | if (sgt->orig_nents) { | |
528 | dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir); | |
529 | sg_free_table(sgt); | |
530 | } | |
531 | } | |
532 | ||
2de440f5 | 533 | static int __spi_map_msg(struct spi_master *master, struct spi_message *msg) |
99adef31 | 534 | { |
99adef31 MB |
535 | struct device *tx_dev, *rx_dev; |
536 | struct spi_transfer *xfer; | |
6ad45a27 | 537 | int ret; |
3a2eba9b | 538 | |
6ad45a27 | 539 | if (!master->can_dma) |
99adef31 MB |
540 | return 0; |
541 | ||
3fc25421 GU |
542 | tx_dev = master->dma_tx->device->dev; |
543 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
544 | |
545 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
546 | if (!master->can_dma(master, msg->spi, xfer)) | |
547 | continue; | |
548 | ||
549 | if (xfer->tx_buf != NULL) { | |
6ad45a27 MB |
550 | ret = spi_map_buf(master, tx_dev, &xfer->tx_sg, |
551 | (void *)xfer->tx_buf, xfer->len, | |
552 | DMA_TO_DEVICE); | |
553 | if (ret != 0) | |
554 | return ret; | |
99adef31 MB |
555 | } |
556 | ||
557 | if (xfer->rx_buf != NULL) { | |
6ad45a27 MB |
558 | ret = spi_map_buf(master, rx_dev, &xfer->rx_sg, |
559 | xfer->rx_buf, xfer->len, | |
560 | DMA_FROM_DEVICE); | |
561 | if (ret != 0) { | |
562 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, | |
563 | DMA_TO_DEVICE); | |
564 | return ret; | |
99adef31 MB |
565 | } |
566 | } | |
567 | } | |
568 | ||
569 | master->cur_msg_mapped = true; | |
570 | ||
571 | return 0; | |
572 | } | |
573 | ||
574 | static int spi_unmap_msg(struct spi_master *master, struct spi_message *msg) | |
575 | { | |
576 | struct spi_transfer *xfer; | |
577 | struct device *tx_dev, *rx_dev; | |
578 | ||
6ad45a27 | 579 | if (!master->cur_msg_mapped || !master->can_dma) |
99adef31 MB |
580 | return 0; |
581 | ||
3fc25421 GU |
582 | tx_dev = master->dma_tx->device->dev; |
583 | rx_dev = master->dma_rx->device->dev; | |
99adef31 MB |
584 | |
585 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
586 | if (!master->can_dma(master, msg->spi, xfer)) | |
587 | continue; | |
588 | ||
6ad45a27 MB |
589 | spi_unmap_buf(master, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE); |
590 | spi_unmap_buf(master, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE); | |
99adef31 MB |
591 | } |
592 | ||
593 | return 0; | |
594 | } | |
2de440f5 GU |
595 | #else /* !CONFIG_HAS_DMA */ |
596 | static inline int __spi_map_msg(struct spi_master *master, | |
597 | struct spi_message *msg) | |
598 | { | |
599 | return 0; | |
600 | } | |
601 | ||
602 | static inline int spi_unmap_msg(struct spi_master *master, | |
603 | struct spi_message *msg) | |
604 | { | |
605 | return 0; | |
606 | } | |
607 | #endif /* !CONFIG_HAS_DMA */ | |
608 | ||
609 | static int spi_map_msg(struct spi_master *master, struct spi_message *msg) | |
610 | { | |
611 | struct spi_transfer *xfer; | |
612 | void *tmp; | |
613 | unsigned int max_tx, max_rx; | |
614 | ||
615 | if (master->flags & (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX)) { | |
616 | max_tx = 0; | |
617 | max_rx = 0; | |
618 | ||
619 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
620 | if ((master->flags & SPI_MASTER_MUST_TX) && | |
621 | !xfer->tx_buf) | |
622 | max_tx = max(xfer->len, max_tx); | |
623 | if ((master->flags & SPI_MASTER_MUST_RX) && | |
624 | !xfer->rx_buf) | |
625 | max_rx = max(xfer->len, max_rx); | |
626 | } | |
627 | ||
628 | if (max_tx) { | |
629 | tmp = krealloc(master->dummy_tx, max_tx, | |
630 | GFP_KERNEL | GFP_DMA); | |
631 | if (!tmp) | |
632 | return -ENOMEM; | |
633 | master->dummy_tx = tmp; | |
634 | memset(tmp, 0, max_tx); | |
635 | } | |
636 | ||
637 | if (max_rx) { | |
638 | tmp = krealloc(master->dummy_rx, max_rx, | |
639 | GFP_KERNEL | GFP_DMA); | |
640 | if (!tmp) | |
641 | return -ENOMEM; | |
642 | master->dummy_rx = tmp; | |
643 | } | |
644 | ||
645 | if (max_tx || max_rx) { | |
646 | list_for_each_entry(xfer, &msg->transfers, | |
647 | transfer_list) { | |
648 | if (!xfer->tx_buf) | |
649 | xfer->tx_buf = master->dummy_tx; | |
650 | if (!xfer->rx_buf) | |
651 | xfer->rx_buf = master->dummy_rx; | |
652 | } | |
653 | } | |
654 | } | |
655 | ||
656 | return __spi_map_msg(master, msg); | |
657 | } | |
99adef31 | 658 | |
b158935f MB |
659 | /* |
660 | * spi_transfer_one_message - Default implementation of transfer_one_message() | |
661 | * | |
662 | * This is a standard implementation of transfer_one_message() for | |
663 | * drivers which impelment a transfer_one() operation. It provides | |
664 | * standard handling of delays and chip select management. | |
665 | */ | |
666 | static int spi_transfer_one_message(struct spi_master *master, | |
667 | struct spi_message *msg) | |
668 | { | |
669 | struct spi_transfer *xfer; | |
b158935f MB |
670 | bool keep_cs = false; |
671 | int ret = 0; | |
682a71b2 | 672 | unsigned long ms = 1; |
b158935f MB |
673 | |
674 | spi_set_cs(msg->spi, true); | |
675 | ||
676 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | |
677 | trace_spi_transfer_start(msg, xfer); | |
678 | ||
38ec10f6 MB |
679 | if (xfer->tx_buf || xfer->rx_buf) { |
680 | reinit_completion(&master->xfer_completion); | |
b158935f | 681 | |
38ec10f6 MB |
682 | ret = master->transfer_one(master, msg->spi, xfer); |
683 | if (ret < 0) { | |
684 | dev_err(&msg->spi->dev, | |
685 | "SPI transfer failed: %d\n", ret); | |
686 | goto out; | |
687 | } | |
b158935f | 688 | |
38ec10f6 MB |
689 | if (ret > 0) { |
690 | ret = 0; | |
691 | ms = xfer->len * 8 * 1000 / xfer->speed_hz; | |
692 | ms += ms + 100; /* some tolerance */ | |
16a0ce4e | 693 | |
38ec10f6 MB |
694 | ms = wait_for_completion_timeout(&master->xfer_completion, |
695 | msecs_to_jiffies(ms)); | |
696 | } | |
16a0ce4e | 697 | |
38ec10f6 MB |
698 | if (ms == 0) { |
699 | dev_err(&msg->spi->dev, | |
700 | "SPI transfer timed out\n"); | |
701 | msg->status = -ETIMEDOUT; | |
702 | } | |
703 | } else { | |
704 | if (xfer->len) | |
705 | dev_err(&msg->spi->dev, | |
706 | "Bufferless transfer has length %u\n", | |
707 | xfer->len); | |
13a42798 | 708 | } |
b158935f MB |
709 | |
710 | trace_spi_transfer_stop(msg, xfer); | |
711 | ||
712 | if (msg->status != -EINPROGRESS) | |
713 | goto out; | |
714 | ||
715 | if (xfer->delay_usecs) | |
716 | udelay(xfer->delay_usecs); | |
717 | ||
718 | if (xfer->cs_change) { | |
719 | if (list_is_last(&xfer->transfer_list, | |
720 | &msg->transfers)) { | |
721 | keep_cs = true; | |
722 | } else { | |
0b73aa63 MB |
723 | spi_set_cs(msg->spi, false); |
724 | udelay(10); | |
725 | spi_set_cs(msg->spi, true); | |
b158935f MB |
726 | } |
727 | } | |
728 | ||
729 | msg->actual_length += xfer->len; | |
730 | } | |
731 | ||
732 | out: | |
733 | if (ret != 0 || !keep_cs) | |
734 | spi_set_cs(msg->spi, false); | |
735 | ||
736 | if (msg->status == -EINPROGRESS) | |
737 | msg->status = ret; | |
738 | ||
ff61eb42 | 739 | if (msg->status && master->handle_err) |
b716c4ff AS |
740 | master->handle_err(master, msg); |
741 | ||
b158935f MB |
742 | spi_finalize_current_message(master); |
743 | ||
744 | return ret; | |
745 | } | |
746 | ||
747 | /** | |
748 | * spi_finalize_current_transfer - report completion of a transfer | |
2c675689 | 749 | * @master: the master reporting completion |
b158935f MB |
750 | * |
751 | * Called by SPI drivers using the core transfer_one_message() | |
752 | * implementation to notify it that the current interrupt driven | |
9e8f4882 | 753 | * transfer has finished and the next one may be scheduled. |
b158935f MB |
754 | */ |
755 | void spi_finalize_current_transfer(struct spi_master *master) | |
756 | { | |
757 | complete(&master->xfer_completion); | |
758 | } | |
759 | EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); | |
760 | ||
ffbbdd21 | 761 | /** |
fc9e0f71 MB |
762 | * __spi_pump_messages - function which processes spi message queue |
763 | * @master: master to process queue for | |
764 | * @in_kthread: true if we are in the context of the message pump thread | |
ffbbdd21 LW |
765 | * |
766 | * This function checks if there is any spi message in the queue that | |
767 | * needs processing and if so call out to the driver to initialize hardware | |
768 | * and transfer each message. | |
769 | * | |
0461a414 MB |
770 | * Note that it is called both from the kthread itself and also from |
771 | * inside spi_sync(); the queue extraction handling at the top of the | |
772 | * function should deal with this safely. | |
ffbbdd21 | 773 | */ |
fc9e0f71 | 774 | static void __spi_pump_messages(struct spi_master *master, bool in_kthread) |
ffbbdd21 | 775 | { |
ffbbdd21 LW |
776 | unsigned long flags; |
777 | bool was_busy = false; | |
778 | int ret; | |
779 | ||
983aee5d | 780 | /* Lock queue */ |
ffbbdd21 | 781 | spin_lock_irqsave(&master->queue_lock, flags); |
983aee5d MB |
782 | |
783 | /* Make sure we are not already running a message */ | |
784 | if (master->cur_msg) { | |
785 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
786 | return; | |
787 | } | |
788 | ||
0461a414 MB |
789 | /* If another context is idling the device then defer */ |
790 | if (master->idling) { | |
791 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
792 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
793 | return; | |
794 | } | |
795 | ||
983aee5d | 796 | /* Check if the queue is idle */ |
ffbbdd21 | 797 | if (list_empty(&master->queue) || !master->running) { |
b0b36b86 BF |
798 | if (!master->busy) { |
799 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
800 | return; | |
ffbbdd21 | 801 | } |
fc9e0f71 MB |
802 | |
803 | /* Only do teardown in the thread */ | |
804 | if (!in_kthread) { | |
805 | queue_kthread_work(&master->kworker, | |
806 | &master->pump_messages); | |
807 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
808 | return; | |
809 | } | |
810 | ||
ffbbdd21 | 811 | master->busy = false; |
0461a414 | 812 | master->idling = true; |
ffbbdd21 | 813 | spin_unlock_irqrestore(&master->queue_lock, flags); |
0461a414 | 814 | |
3a2eba9b MB |
815 | kfree(master->dummy_rx); |
816 | master->dummy_rx = NULL; | |
817 | kfree(master->dummy_tx); | |
818 | master->dummy_tx = NULL; | |
b0b36b86 BF |
819 | if (master->unprepare_transfer_hardware && |
820 | master->unprepare_transfer_hardware(master)) | |
821 | dev_err(&master->dev, | |
822 | "failed to unprepare transfer hardware\n"); | |
49834de2 MB |
823 | if (master->auto_runtime_pm) { |
824 | pm_runtime_mark_last_busy(master->dev.parent); | |
825 | pm_runtime_put_autosuspend(master->dev.parent); | |
826 | } | |
56ec1978 | 827 | trace_spi_master_idle(master); |
ffbbdd21 | 828 | |
0461a414 MB |
829 | spin_lock_irqsave(&master->queue_lock, flags); |
830 | master->idling = false; | |
ffbbdd21 LW |
831 | spin_unlock_irqrestore(&master->queue_lock, flags); |
832 | return; | |
833 | } | |
ffbbdd21 | 834 | |
ffbbdd21 LW |
835 | /* Extract head of queue */ |
836 | master->cur_msg = | |
a89e2d27 | 837 | list_first_entry(&master->queue, struct spi_message, queue); |
ffbbdd21 LW |
838 | |
839 | list_del_init(&master->cur_msg->queue); | |
840 | if (master->busy) | |
841 | was_busy = true; | |
842 | else | |
843 | master->busy = true; | |
844 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
845 | ||
49834de2 MB |
846 | if (!was_busy && master->auto_runtime_pm) { |
847 | ret = pm_runtime_get_sync(master->dev.parent); | |
848 | if (ret < 0) { | |
849 | dev_err(&master->dev, "Failed to power device: %d\n", | |
850 | ret); | |
851 | return; | |
852 | } | |
853 | } | |
854 | ||
56ec1978 MB |
855 | if (!was_busy) |
856 | trace_spi_master_busy(master); | |
857 | ||
7dfd2bd7 | 858 | if (!was_busy && master->prepare_transfer_hardware) { |
ffbbdd21 LW |
859 | ret = master->prepare_transfer_hardware(master); |
860 | if (ret) { | |
861 | dev_err(&master->dev, | |
862 | "failed to prepare transfer hardware\n"); | |
49834de2 MB |
863 | |
864 | if (master->auto_runtime_pm) | |
865 | pm_runtime_put(master->dev.parent); | |
ffbbdd21 LW |
866 | return; |
867 | } | |
868 | } | |
869 | ||
56ec1978 MB |
870 | trace_spi_message_start(master->cur_msg); |
871 | ||
2841a5fc MB |
872 | if (master->prepare_message) { |
873 | ret = master->prepare_message(master, master->cur_msg); | |
874 | if (ret) { | |
875 | dev_err(&master->dev, | |
876 | "failed to prepare message: %d\n", ret); | |
877 | master->cur_msg->status = ret; | |
878 | spi_finalize_current_message(master); | |
879 | return; | |
880 | } | |
881 | master->cur_msg_prepared = true; | |
882 | } | |
883 | ||
99adef31 MB |
884 | ret = spi_map_msg(master, master->cur_msg); |
885 | if (ret) { | |
886 | master->cur_msg->status = ret; | |
887 | spi_finalize_current_message(master); | |
888 | return; | |
889 | } | |
890 | ||
ffbbdd21 LW |
891 | ret = master->transfer_one_message(master, master->cur_msg); |
892 | if (ret) { | |
893 | dev_err(&master->dev, | |
1f802f82 | 894 | "failed to transfer one message from queue\n"); |
ffbbdd21 LW |
895 | return; |
896 | } | |
897 | } | |
898 | ||
fc9e0f71 MB |
899 | /** |
900 | * spi_pump_messages - kthread work function which processes spi message queue | |
901 | * @work: pointer to kthread work struct contained in the master struct | |
902 | */ | |
903 | static void spi_pump_messages(struct kthread_work *work) | |
904 | { | |
905 | struct spi_master *master = | |
906 | container_of(work, struct spi_master, pump_messages); | |
907 | ||
908 | __spi_pump_messages(master, true); | |
909 | } | |
910 | ||
ffbbdd21 LW |
911 | static int spi_init_queue(struct spi_master *master) |
912 | { | |
913 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
914 | ||
ffbbdd21 LW |
915 | master->running = false; |
916 | master->busy = false; | |
917 | ||
918 | init_kthread_worker(&master->kworker); | |
919 | master->kworker_task = kthread_run(kthread_worker_fn, | |
f170168b | 920 | &master->kworker, "%s", |
ffbbdd21 LW |
921 | dev_name(&master->dev)); |
922 | if (IS_ERR(master->kworker_task)) { | |
923 | dev_err(&master->dev, "failed to create message pump task\n"); | |
98a8f5a0 | 924 | return PTR_ERR(master->kworker_task); |
ffbbdd21 LW |
925 | } |
926 | init_kthread_work(&master->pump_messages, spi_pump_messages); | |
927 | ||
928 | /* | |
929 | * Master config will indicate if this controller should run the | |
930 | * message pump with high (realtime) priority to reduce the transfer | |
931 | * latency on the bus by minimising the delay between a transfer | |
932 | * request and the scheduling of the message pump thread. Without this | |
933 | * setting the message pump thread will remain at default priority. | |
934 | */ | |
935 | if (master->rt) { | |
936 | dev_info(&master->dev, | |
937 | "will run message pump with realtime priority\n"); | |
938 | sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m); | |
939 | } | |
940 | ||
941 | return 0; | |
942 | } | |
943 | ||
944 | /** | |
945 | * spi_get_next_queued_message() - called by driver to check for queued | |
946 | * messages | |
947 | * @master: the master to check for queued messages | |
948 | * | |
949 | * If there are more messages in the queue, the next message is returned from | |
950 | * this call. | |
951 | */ | |
952 | struct spi_message *spi_get_next_queued_message(struct spi_master *master) | |
953 | { | |
954 | struct spi_message *next; | |
955 | unsigned long flags; | |
956 | ||
957 | /* get a pointer to the next message, if any */ | |
958 | spin_lock_irqsave(&master->queue_lock, flags); | |
1cfd97f9 AL |
959 | next = list_first_entry_or_null(&master->queue, struct spi_message, |
960 | queue); | |
ffbbdd21 LW |
961 | spin_unlock_irqrestore(&master->queue_lock, flags); |
962 | ||
963 | return next; | |
964 | } | |
965 | EXPORT_SYMBOL_GPL(spi_get_next_queued_message); | |
966 | ||
967 | /** | |
968 | * spi_finalize_current_message() - the current message is complete | |
969 | * @master: the master to return the message to | |
970 | * | |
971 | * Called by the driver to notify the core that the message in the front of the | |
972 | * queue is complete and can be removed from the queue. | |
973 | */ | |
974 | void spi_finalize_current_message(struct spi_master *master) | |
975 | { | |
976 | struct spi_message *mesg; | |
977 | unsigned long flags; | |
2841a5fc | 978 | int ret; |
ffbbdd21 LW |
979 | |
980 | spin_lock_irqsave(&master->queue_lock, flags); | |
981 | mesg = master->cur_msg; | |
982 | master->cur_msg = NULL; | |
983 | ||
984 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
985 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
986 | ||
99adef31 MB |
987 | spi_unmap_msg(master, mesg); |
988 | ||
2841a5fc MB |
989 | if (master->cur_msg_prepared && master->unprepare_message) { |
990 | ret = master->unprepare_message(master, mesg); | |
991 | if (ret) { | |
992 | dev_err(&master->dev, | |
993 | "failed to unprepare message: %d\n", ret); | |
994 | } | |
995 | } | |
391949b6 UKK |
996 | |
997 | trace_spi_message_done(mesg); | |
998 | ||
2841a5fc MB |
999 | master->cur_msg_prepared = false; |
1000 | ||
ffbbdd21 LW |
1001 | mesg->state = NULL; |
1002 | if (mesg->complete) | |
1003 | mesg->complete(mesg->context); | |
1004 | } | |
1005 | EXPORT_SYMBOL_GPL(spi_finalize_current_message); | |
1006 | ||
1007 | static int spi_start_queue(struct spi_master *master) | |
1008 | { | |
1009 | unsigned long flags; | |
1010 | ||
1011 | spin_lock_irqsave(&master->queue_lock, flags); | |
1012 | ||
1013 | if (master->running || master->busy) { | |
1014 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1015 | return -EBUSY; | |
1016 | } | |
1017 | ||
1018 | master->running = true; | |
1019 | master->cur_msg = NULL; | |
1020 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1021 | ||
1022 | queue_kthread_work(&master->kworker, &master->pump_messages); | |
1023 | ||
1024 | return 0; | |
1025 | } | |
1026 | ||
1027 | static int spi_stop_queue(struct spi_master *master) | |
1028 | { | |
1029 | unsigned long flags; | |
1030 | unsigned limit = 500; | |
1031 | int ret = 0; | |
1032 | ||
1033 | spin_lock_irqsave(&master->queue_lock, flags); | |
1034 | ||
1035 | /* | |
1036 | * This is a bit lame, but is optimized for the common execution path. | |
1037 | * A wait_queue on the master->busy could be used, but then the common | |
1038 | * execution path (pump_messages) would be required to call wake_up or | |
1039 | * friends on every SPI message. Do this instead. | |
1040 | */ | |
1041 | while ((!list_empty(&master->queue) || master->busy) && limit--) { | |
1042 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
f97b26b0 | 1043 | usleep_range(10000, 11000); |
ffbbdd21 LW |
1044 | spin_lock_irqsave(&master->queue_lock, flags); |
1045 | } | |
1046 | ||
1047 | if (!list_empty(&master->queue) || master->busy) | |
1048 | ret = -EBUSY; | |
1049 | else | |
1050 | master->running = false; | |
1051 | ||
1052 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1053 | ||
1054 | if (ret) { | |
1055 | dev_warn(&master->dev, | |
1056 | "could not stop message queue\n"); | |
1057 | return ret; | |
1058 | } | |
1059 | return ret; | |
1060 | } | |
1061 | ||
1062 | static int spi_destroy_queue(struct spi_master *master) | |
1063 | { | |
1064 | int ret; | |
1065 | ||
1066 | ret = spi_stop_queue(master); | |
1067 | ||
1068 | /* | |
1069 | * flush_kthread_worker will block until all work is done. | |
1070 | * If the reason that stop_queue timed out is that the work will never | |
1071 | * finish, then it does no good to call flush/stop thread, so | |
1072 | * return anyway. | |
1073 | */ | |
1074 | if (ret) { | |
1075 | dev_err(&master->dev, "problem destroying queue\n"); | |
1076 | return ret; | |
1077 | } | |
1078 | ||
1079 | flush_kthread_worker(&master->kworker); | |
1080 | kthread_stop(master->kworker_task); | |
1081 | ||
1082 | return 0; | |
1083 | } | |
1084 | ||
0461a414 MB |
1085 | static int __spi_queued_transfer(struct spi_device *spi, |
1086 | struct spi_message *msg, | |
1087 | bool need_pump) | |
ffbbdd21 LW |
1088 | { |
1089 | struct spi_master *master = spi->master; | |
1090 | unsigned long flags; | |
1091 | ||
1092 | spin_lock_irqsave(&master->queue_lock, flags); | |
1093 | ||
1094 | if (!master->running) { | |
1095 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1096 | return -ESHUTDOWN; | |
1097 | } | |
1098 | msg->actual_length = 0; | |
1099 | msg->status = -EINPROGRESS; | |
1100 | ||
1101 | list_add_tail(&msg->queue, &master->queue); | |
0461a414 | 1102 | if (!master->busy && need_pump) |
ffbbdd21 LW |
1103 | queue_kthread_work(&master->kworker, &master->pump_messages); |
1104 | ||
1105 | spin_unlock_irqrestore(&master->queue_lock, flags); | |
1106 | return 0; | |
1107 | } | |
1108 | ||
0461a414 MB |
1109 | /** |
1110 | * spi_queued_transfer - transfer function for queued transfers | |
1111 | * @spi: spi device which is requesting transfer | |
1112 | * @msg: spi message which is to handled is queued to driver queue | |
1113 | */ | |
1114 | static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg) | |
1115 | { | |
1116 | return __spi_queued_transfer(spi, msg, true); | |
1117 | } | |
1118 | ||
ffbbdd21 LW |
1119 | static int spi_master_initialize_queue(struct spi_master *master) |
1120 | { | |
1121 | int ret; | |
1122 | ||
ffbbdd21 | 1123 | master->transfer = spi_queued_transfer; |
b158935f MB |
1124 | if (!master->transfer_one_message) |
1125 | master->transfer_one_message = spi_transfer_one_message; | |
ffbbdd21 LW |
1126 | |
1127 | /* Initialize and start queue */ | |
1128 | ret = spi_init_queue(master); | |
1129 | if (ret) { | |
1130 | dev_err(&master->dev, "problem initializing queue\n"); | |
1131 | goto err_init_queue; | |
1132 | } | |
c3676d5c | 1133 | master->queued = true; |
ffbbdd21 LW |
1134 | ret = spi_start_queue(master); |
1135 | if (ret) { | |
1136 | dev_err(&master->dev, "problem starting queue\n"); | |
1137 | goto err_start_queue; | |
1138 | } | |
1139 | ||
1140 | return 0; | |
1141 | ||
1142 | err_start_queue: | |
ffbbdd21 | 1143 | spi_destroy_queue(master); |
c3676d5c | 1144 | err_init_queue: |
ffbbdd21 LW |
1145 | return ret; |
1146 | } | |
1147 | ||
1148 | /*-------------------------------------------------------------------------*/ | |
1149 | ||
7cb94361 | 1150 | #if defined(CONFIG_OF) |
aff5e3f8 PA |
1151 | static struct spi_device * |
1152 | of_register_spi_device(struct spi_master *master, struct device_node *nc) | |
1153 | { | |
1154 | struct spi_device *spi; | |
1155 | int rc; | |
1156 | u32 value; | |
1157 | ||
1158 | /* Alloc an spi_device */ | |
1159 | spi = spi_alloc_device(master); | |
1160 | if (!spi) { | |
1161 | dev_err(&master->dev, "spi_device alloc error for %s\n", | |
1162 | nc->full_name); | |
1163 | rc = -ENOMEM; | |
1164 | goto err_out; | |
1165 | } | |
1166 | ||
1167 | /* Select device driver */ | |
1168 | rc = of_modalias_node(nc, spi->modalias, | |
1169 | sizeof(spi->modalias)); | |
1170 | if (rc < 0) { | |
1171 | dev_err(&master->dev, "cannot find modalias for %s\n", | |
1172 | nc->full_name); | |
1173 | goto err_out; | |
1174 | } | |
1175 | ||
1176 | /* Device address */ | |
1177 | rc = of_property_read_u32(nc, "reg", &value); | |
1178 | if (rc) { | |
1179 | dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n", | |
1180 | nc->full_name, rc); | |
1181 | goto err_out; | |
1182 | } | |
1183 | spi->chip_select = value; | |
1184 | ||
1185 | /* Mode (clock phase/polarity/etc.) */ | |
1186 | if (of_find_property(nc, "spi-cpha", NULL)) | |
1187 | spi->mode |= SPI_CPHA; | |
1188 | if (of_find_property(nc, "spi-cpol", NULL)) | |
1189 | spi->mode |= SPI_CPOL; | |
1190 | if (of_find_property(nc, "spi-cs-high", NULL)) | |
1191 | spi->mode |= SPI_CS_HIGH; | |
1192 | if (of_find_property(nc, "spi-3wire", NULL)) | |
1193 | spi->mode |= SPI_3WIRE; | |
1194 | if (of_find_property(nc, "spi-lsb-first", NULL)) | |
1195 | spi->mode |= SPI_LSB_FIRST; | |
1196 | ||
1197 | /* Device DUAL/QUAD mode */ | |
1198 | if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { | |
1199 | switch (value) { | |
1200 | case 1: | |
1201 | break; | |
1202 | case 2: | |
1203 | spi->mode |= SPI_TX_DUAL; | |
1204 | break; | |
1205 | case 4: | |
1206 | spi->mode |= SPI_TX_QUAD; | |
1207 | break; | |
1208 | default: | |
1209 | dev_warn(&master->dev, | |
1210 | "spi-tx-bus-width %d not supported\n", | |
1211 | value); | |
1212 | break; | |
1213 | } | |
1214 | } | |
1215 | ||
1216 | if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { | |
1217 | switch (value) { | |
1218 | case 1: | |
1219 | break; | |
1220 | case 2: | |
1221 | spi->mode |= SPI_RX_DUAL; | |
1222 | break; | |
1223 | case 4: | |
1224 | spi->mode |= SPI_RX_QUAD; | |
1225 | break; | |
1226 | default: | |
1227 | dev_warn(&master->dev, | |
1228 | "spi-rx-bus-width %d not supported\n", | |
1229 | value); | |
1230 | break; | |
1231 | } | |
1232 | } | |
1233 | ||
1234 | /* Device speed */ | |
1235 | rc = of_property_read_u32(nc, "spi-max-frequency", &value); | |
1236 | if (rc) { | |
1237 | dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n", | |
1238 | nc->full_name, rc); | |
1239 | goto err_out; | |
1240 | } | |
1241 | spi->max_speed_hz = value; | |
1242 | ||
1243 | /* IRQ */ | |
1244 | spi->irq = irq_of_parse_and_map(nc, 0); | |
1245 | ||
1246 | /* Store a pointer to the node in the device structure */ | |
1247 | of_node_get(nc); | |
1248 | spi->dev.of_node = nc; | |
1249 | ||
1250 | /* Register the new device */ | |
aff5e3f8 PA |
1251 | rc = spi_add_device(spi); |
1252 | if (rc) { | |
1253 | dev_err(&master->dev, "spi_device register error %s\n", | |
1254 | nc->full_name); | |
1255 | goto err_out; | |
1256 | } | |
1257 | ||
1258 | return spi; | |
1259 | ||
1260 | err_out: | |
1261 | spi_dev_put(spi); | |
1262 | return ERR_PTR(rc); | |
1263 | } | |
1264 | ||
d57a4282 GL |
1265 | /** |
1266 | * of_register_spi_devices() - Register child devices onto the SPI bus | |
1267 | * @master: Pointer to spi_master device | |
1268 | * | |
1269 | * Registers an spi_device for each child node of master node which has a 'reg' | |
1270 | * property. | |
1271 | */ | |
1272 | static void of_register_spi_devices(struct spi_master *master) | |
1273 | { | |
1274 | struct spi_device *spi; | |
1275 | struct device_node *nc; | |
d57a4282 GL |
1276 | |
1277 | if (!master->dev.of_node) | |
1278 | return; | |
1279 | ||
f3b6159e | 1280 | for_each_available_child_of_node(master->dev.of_node, nc) { |
aff5e3f8 PA |
1281 | spi = of_register_spi_device(master, nc); |
1282 | if (IS_ERR(spi)) | |
1283 | dev_warn(&master->dev, "Failed to create SPI device for %s\n", | |
d57a4282 | 1284 | nc->full_name); |
d57a4282 GL |
1285 | } |
1286 | } | |
1287 | #else | |
1288 | static void of_register_spi_devices(struct spi_master *master) { } | |
1289 | #endif | |
1290 | ||
64bee4d2 MW |
1291 | #ifdef CONFIG_ACPI |
1292 | static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) | |
1293 | { | |
1294 | struct spi_device *spi = data; | |
1295 | ||
1296 | if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { | |
1297 | struct acpi_resource_spi_serialbus *sb; | |
1298 | ||
1299 | sb = &ares->data.spi_serial_bus; | |
1300 | if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { | |
1301 | spi->chip_select = sb->device_selection; | |
1302 | spi->max_speed_hz = sb->connection_speed; | |
1303 | ||
1304 | if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) | |
1305 | spi->mode |= SPI_CPHA; | |
1306 | if (sb->clock_polarity == ACPI_SPI_START_HIGH) | |
1307 | spi->mode |= SPI_CPOL; | |
1308 | if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) | |
1309 | spi->mode |= SPI_CS_HIGH; | |
1310 | } | |
1311 | } else if (spi->irq < 0) { | |
1312 | struct resource r; | |
1313 | ||
1314 | if (acpi_dev_resource_interrupt(ares, 0, &r)) | |
1315 | spi->irq = r.start; | |
1316 | } | |
1317 | ||
1318 | /* Always tell the ACPI core to skip this resource */ | |
1319 | return 1; | |
1320 | } | |
1321 | ||
1322 | static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, | |
1323 | void *data, void **return_value) | |
1324 | { | |
1325 | struct spi_master *master = data; | |
1326 | struct list_head resource_list; | |
1327 | struct acpi_device *adev; | |
1328 | struct spi_device *spi; | |
1329 | int ret; | |
1330 | ||
1331 | if (acpi_bus_get_device(handle, &adev)) | |
1332 | return AE_OK; | |
1333 | if (acpi_bus_get_status(adev) || !adev->status.present) | |
1334 | return AE_OK; | |
1335 | ||
1336 | spi = spi_alloc_device(master); | |
1337 | if (!spi) { | |
1338 | dev_err(&master->dev, "failed to allocate SPI device for %s\n", | |
1339 | dev_name(&adev->dev)); | |
1340 | return AE_NO_MEMORY; | |
1341 | } | |
1342 | ||
7b199811 | 1343 | ACPI_COMPANION_SET(&spi->dev, adev); |
64bee4d2 MW |
1344 | spi->irq = -1; |
1345 | ||
1346 | INIT_LIST_HEAD(&resource_list); | |
1347 | ret = acpi_dev_get_resources(adev, &resource_list, | |
1348 | acpi_spi_add_resource, spi); | |
1349 | acpi_dev_free_resource_list(&resource_list); | |
1350 | ||
1351 | if (ret < 0 || !spi->max_speed_hz) { | |
1352 | spi_dev_put(spi); | |
1353 | return AE_OK; | |
1354 | } | |
1355 | ||
33cf00e5 | 1356 | adev->power.flags.ignore_parent = true; |
cf9eb39c | 1357 | strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); |
64bee4d2 | 1358 | if (spi_add_device(spi)) { |
33cf00e5 | 1359 | adev->power.flags.ignore_parent = false; |
64bee4d2 MW |
1360 | dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", |
1361 | dev_name(&adev->dev)); | |
1362 | spi_dev_put(spi); | |
1363 | } | |
1364 | ||
1365 | return AE_OK; | |
1366 | } | |
1367 | ||
1368 | static void acpi_register_spi_devices(struct spi_master *master) | |
1369 | { | |
1370 | acpi_status status; | |
1371 | acpi_handle handle; | |
1372 | ||
29896178 | 1373 | handle = ACPI_HANDLE(master->dev.parent); |
64bee4d2 MW |
1374 | if (!handle) |
1375 | return; | |
1376 | ||
1377 | status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
1378 | acpi_spi_add_device, NULL, | |
1379 | master, NULL); | |
1380 | if (ACPI_FAILURE(status)) | |
1381 | dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); | |
1382 | } | |
1383 | #else | |
1384 | static inline void acpi_register_spi_devices(struct spi_master *master) {} | |
1385 | #endif /* CONFIG_ACPI */ | |
1386 | ||
49dce689 | 1387 | static void spi_master_release(struct device *dev) |
8ae12a0d DB |
1388 | { |
1389 | struct spi_master *master; | |
1390 | ||
49dce689 | 1391 | master = container_of(dev, struct spi_master, dev); |
8ae12a0d DB |
1392 | kfree(master); |
1393 | } | |
1394 | ||
1395 | static struct class spi_master_class = { | |
1396 | .name = "spi_master", | |
1397 | .owner = THIS_MODULE, | |
49dce689 | 1398 | .dev_release = spi_master_release, |
8ae12a0d DB |
1399 | }; |
1400 | ||
1401 | ||
ffbbdd21 | 1402 | |
8ae12a0d DB |
1403 | /** |
1404 | * spi_alloc_master - allocate SPI master controller | |
1405 | * @dev: the controller, possibly using the platform_bus | |
33e34dc6 | 1406 | * @size: how much zeroed driver-private data to allocate; the pointer to this |
49dce689 | 1407 | * memory is in the driver_data field of the returned device, |
0c868461 | 1408 | * accessible with spi_master_get_devdata(). |
33e34dc6 | 1409 | * Context: can sleep |
8ae12a0d DB |
1410 | * |
1411 | * This call is used only by SPI master controller drivers, which are the | |
1412 | * only ones directly touching chip registers. It's how they allocate | |
ba1a0513 | 1413 | * an spi_master structure, prior to calling spi_register_master(). |
8ae12a0d DB |
1414 | * |
1415 | * This must be called from context that can sleep. It returns the SPI | |
1416 | * master structure on success, else NULL. | |
1417 | * | |
1418 | * The caller is responsible for assigning the bus number and initializing | |
ba1a0513 | 1419 | * the master's methods before calling spi_register_master(); and (after errors |
eb4af0f5 UKK |
1420 | * adding the device) calling spi_master_put() and kfree() to prevent a memory |
1421 | * leak. | |
8ae12a0d | 1422 | */ |
e9d5a461 | 1423 | struct spi_master *spi_alloc_master(struct device *dev, unsigned size) |
8ae12a0d DB |
1424 | { |
1425 | struct spi_master *master; | |
1426 | ||
0c868461 DB |
1427 | if (!dev) |
1428 | return NULL; | |
1429 | ||
5fe5f05e | 1430 | master = kzalloc(size + sizeof(*master), GFP_KERNEL); |
8ae12a0d DB |
1431 | if (!master) |
1432 | return NULL; | |
1433 | ||
49dce689 | 1434 | device_initialize(&master->dev); |
1e8a52e1 GL |
1435 | master->bus_num = -1; |
1436 | master->num_chipselect = 1; | |
49dce689 TJ |
1437 | master->dev.class = &spi_master_class; |
1438 | master->dev.parent = get_device(dev); | |
0c868461 | 1439 | spi_master_set_devdata(master, &master[1]); |
8ae12a0d DB |
1440 | |
1441 | return master; | |
1442 | } | |
1443 | EXPORT_SYMBOL_GPL(spi_alloc_master); | |
1444 | ||
74317984 JCPV |
1445 | #ifdef CONFIG_OF |
1446 | static int of_spi_register_master(struct spi_master *master) | |
1447 | { | |
e80beb27 | 1448 | int nb, i, *cs; |
74317984 JCPV |
1449 | struct device_node *np = master->dev.of_node; |
1450 | ||
1451 | if (!np) | |
1452 | return 0; | |
1453 | ||
1454 | nb = of_gpio_named_count(np, "cs-gpios"); | |
5fe5f05e | 1455 | master->num_chipselect = max_t(int, nb, master->num_chipselect); |
74317984 | 1456 | |
8ec5d84e AL |
1457 | /* Return error only for an incorrectly formed cs-gpios property */ |
1458 | if (nb == 0 || nb == -ENOENT) | |
74317984 | 1459 | return 0; |
8ec5d84e AL |
1460 | else if (nb < 0) |
1461 | return nb; | |
74317984 JCPV |
1462 | |
1463 | cs = devm_kzalloc(&master->dev, | |
1464 | sizeof(int) * master->num_chipselect, | |
1465 | GFP_KERNEL); | |
1466 | master->cs_gpios = cs; | |
1467 | ||
1468 | if (!master->cs_gpios) | |
1469 | return -ENOMEM; | |
1470 | ||
0da83bb1 | 1471 | for (i = 0; i < master->num_chipselect; i++) |
446411e1 | 1472 | cs[i] = -ENOENT; |
74317984 JCPV |
1473 | |
1474 | for (i = 0; i < nb; i++) | |
1475 | cs[i] = of_get_named_gpio(np, "cs-gpios", i); | |
1476 | ||
1477 | return 0; | |
1478 | } | |
1479 | #else | |
1480 | static int of_spi_register_master(struct spi_master *master) | |
1481 | { | |
1482 | return 0; | |
1483 | } | |
1484 | #endif | |
1485 | ||
8ae12a0d DB |
1486 | /** |
1487 | * spi_register_master - register SPI master controller | |
1488 | * @master: initialized master, originally from spi_alloc_master() | |
33e34dc6 | 1489 | * Context: can sleep |
8ae12a0d DB |
1490 | * |
1491 | * SPI master controllers connect to their drivers using some non-SPI bus, | |
1492 | * such as the platform bus. The final stage of probe() in that code | |
1493 | * includes calling spi_register_master() to hook up to this SPI bus glue. | |
1494 | * | |
1495 | * SPI controllers use board specific (often SOC specific) bus numbers, | |
1496 | * and board-specific addressing for SPI devices combines those numbers | |
1497 | * with chip select numbers. Since SPI does not directly support dynamic | |
1498 | * device identification, boards need configuration tables telling which | |
1499 | * chip is at which address. | |
1500 | * | |
1501 | * This must be called from context that can sleep. It returns zero on | |
1502 | * success, else a negative error code (dropping the master's refcount). | |
0c868461 DB |
1503 | * After a successful return, the caller is responsible for calling |
1504 | * spi_unregister_master(). | |
8ae12a0d | 1505 | */ |
e9d5a461 | 1506 | int spi_register_master(struct spi_master *master) |
8ae12a0d | 1507 | { |
e44a45ae | 1508 | static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); |
49dce689 | 1509 | struct device *dev = master->dev.parent; |
2b9603a0 | 1510 | struct boardinfo *bi; |
8ae12a0d DB |
1511 | int status = -ENODEV; |
1512 | int dynamic = 0; | |
1513 | ||
0c868461 DB |
1514 | if (!dev) |
1515 | return -ENODEV; | |
1516 | ||
74317984 JCPV |
1517 | status = of_spi_register_master(master); |
1518 | if (status) | |
1519 | return status; | |
1520 | ||
082c8cb4 DB |
1521 | /* even if it's just one always-selected device, there must |
1522 | * be at least one chipselect | |
1523 | */ | |
1524 | if (master->num_chipselect == 0) | |
1525 | return -EINVAL; | |
1526 | ||
bb29785e GL |
1527 | if ((master->bus_num < 0) && master->dev.of_node) |
1528 | master->bus_num = of_alias_get_id(master->dev.of_node, "spi"); | |
1529 | ||
8ae12a0d | 1530 | /* convention: dynamically assigned bus IDs count down from the max */ |
a020ed75 | 1531 | if (master->bus_num < 0) { |
082c8cb4 DB |
1532 | /* FIXME switch to an IDR based scheme, something like |
1533 | * I2C now uses, so we can't run out of "dynamic" IDs | |
1534 | */ | |
8ae12a0d | 1535 | master->bus_num = atomic_dec_return(&dyn_bus_id); |
b885244e | 1536 | dynamic = 1; |
8ae12a0d DB |
1537 | } |
1538 | ||
5424d43e MB |
1539 | INIT_LIST_HEAD(&master->queue); |
1540 | spin_lock_init(&master->queue_lock); | |
cf32b71e ES |
1541 | spin_lock_init(&master->bus_lock_spinlock); |
1542 | mutex_init(&master->bus_lock_mutex); | |
1543 | master->bus_lock_flag = 0; | |
b158935f | 1544 | init_completion(&master->xfer_completion); |
6ad45a27 MB |
1545 | if (!master->max_dma_len) |
1546 | master->max_dma_len = INT_MAX; | |
cf32b71e | 1547 | |
8ae12a0d DB |
1548 | /* register the device, then userspace will see it. |
1549 | * registration fails if the bus ID is in use. | |
1550 | */ | |
35f74fca | 1551 | dev_set_name(&master->dev, "spi%u", master->bus_num); |
49dce689 | 1552 | status = device_add(&master->dev); |
b885244e | 1553 | if (status < 0) |
8ae12a0d | 1554 | goto done; |
35f74fca | 1555 | dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), |
8ae12a0d DB |
1556 | dynamic ? " (dynamic)" : ""); |
1557 | ||
ffbbdd21 LW |
1558 | /* If we're using a queued driver, start the queue */ |
1559 | if (master->transfer) | |
1560 | dev_info(dev, "master is unqueued, this is deprecated\n"); | |
1561 | else { | |
1562 | status = spi_master_initialize_queue(master); | |
1563 | if (status) { | |
e93b0724 | 1564 | device_del(&master->dev); |
ffbbdd21 LW |
1565 | goto done; |
1566 | } | |
1567 | } | |
1568 | ||
2b9603a0 FT |
1569 | mutex_lock(&board_lock); |
1570 | list_add_tail(&master->list, &spi_master_list); | |
1571 | list_for_each_entry(bi, &board_list, list) | |
1572 | spi_match_master_to_boardinfo(master, &bi->board_info); | |
1573 | mutex_unlock(&board_lock); | |
1574 | ||
64bee4d2 | 1575 | /* Register devices from the device tree and ACPI */ |
12b15e83 | 1576 | of_register_spi_devices(master); |
64bee4d2 | 1577 | acpi_register_spi_devices(master); |
8ae12a0d DB |
1578 | done: |
1579 | return status; | |
1580 | } | |
1581 | EXPORT_SYMBOL_GPL(spi_register_master); | |
1582 | ||
666d5b4c MB |
1583 | static void devm_spi_unregister(struct device *dev, void *res) |
1584 | { | |
1585 | spi_unregister_master(*(struct spi_master **)res); | |
1586 | } | |
1587 | ||
1588 | /** | |
1589 | * dev_spi_register_master - register managed SPI master controller | |
1590 | * @dev: device managing SPI master | |
1591 | * @master: initialized master, originally from spi_alloc_master() | |
1592 | * Context: can sleep | |
1593 | * | |
1594 | * Register a SPI device as with spi_register_master() which will | |
1595 | * automatically be unregister | |
1596 | */ | |
1597 | int devm_spi_register_master(struct device *dev, struct spi_master *master) | |
1598 | { | |
1599 | struct spi_master **ptr; | |
1600 | int ret; | |
1601 | ||
1602 | ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL); | |
1603 | if (!ptr) | |
1604 | return -ENOMEM; | |
1605 | ||
1606 | ret = spi_register_master(master); | |
4b92894e | 1607 | if (!ret) { |
666d5b4c MB |
1608 | *ptr = master; |
1609 | devres_add(dev, ptr); | |
1610 | } else { | |
1611 | devres_free(ptr); | |
1612 | } | |
1613 | ||
1614 | return ret; | |
1615 | } | |
1616 | EXPORT_SYMBOL_GPL(devm_spi_register_master); | |
1617 | ||
34860089 | 1618 | static int __unregister(struct device *dev, void *null) |
8ae12a0d | 1619 | { |
34860089 | 1620 | spi_unregister_device(to_spi_device(dev)); |
8ae12a0d DB |
1621 | return 0; |
1622 | } | |
1623 | ||
1624 | /** | |
1625 | * spi_unregister_master - unregister SPI master controller | |
1626 | * @master: the master being unregistered | |
33e34dc6 | 1627 | * Context: can sleep |
8ae12a0d DB |
1628 | * |
1629 | * This call is used only by SPI master controller drivers, which are the | |
1630 | * only ones directly touching chip registers. | |
1631 | * | |
1632 | * This must be called from context that can sleep. | |
1633 | */ | |
1634 | void spi_unregister_master(struct spi_master *master) | |
1635 | { | |
89fc9a1a JG |
1636 | int dummy; |
1637 | ||
ffbbdd21 LW |
1638 | if (master->queued) { |
1639 | if (spi_destroy_queue(master)) | |
1640 | dev_err(&master->dev, "queue remove failed\n"); | |
1641 | } | |
1642 | ||
2b9603a0 FT |
1643 | mutex_lock(&board_lock); |
1644 | list_del(&master->list); | |
1645 | mutex_unlock(&board_lock); | |
1646 | ||
97dbf37d | 1647 | dummy = device_for_each_child(&master->dev, NULL, __unregister); |
49dce689 | 1648 | device_unregister(&master->dev); |
8ae12a0d DB |
1649 | } |
1650 | EXPORT_SYMBOL_GPL(spi_unregister_master); | |
1651 | ||
ffbbdd21 LW |
1652 | int spi_master_suspend(struct spi_master *master) |
1653 | { | |
1654 | int ret; | |
1655 | ||
1656 | /* Basically no-ops for non-queued masters */ | |
1657 | if (!master->queued) | |
1658 | return 0; | |
1659 | ||
1660 | ret = spi_stop_queue(master); | |
1661 | if (ret) | |
1662 | dev_err(&master->dev, "queue stop failed\n"); | |
1663 | ||
1664 | return ret; | |
1665 | } | |
1666 | EXPORT_SYMBOL_GPL(spi_master_suspend); | |
1667 | ||
1668 | int spi_master_resume(struct spi_master *master) | |
1669 | { | |
1670 | int ret; | |
1671 | ||
1672 | if (!master->queued) | |
1673 | return 0; | |
1674 | ||
1675 | ret = spi_start_queue(master); | |
1676 | if (ret) | |
1677 | dev_err(&master->dev, "queue restart failed\n"); | |
1678 | ||
1679 | return ret; | |
1680 | } | |
1681 | EXPORT_SYMBOL_GPL(spi_master_resume); | |
1682 | ||
9f3b795a | 1683 | static int __spi_master_match(struct device *dev, const void *data) |
5ed2c832 DY |
1684 | { |
1685 | struct spi_master *m; | |
9f3b795a | 1686 | const u16 *bus_num = data; |
5ed2c832 DY |
1687 | |
1688 | m = container_of(dev, struct spi_master, dev); | |
1689 | return m->bus_num == *bus_num; | |
1690 | } | |
1691 | ||
8ae12a0d DB |
1692 | /** |
1693 | * spi_busnum_to_master - look up master associated with bus_num | |
1694 | * @bus_num: the master's bus number | |
33e34dc6 | 1695 | * Context: can sleep |
8ae12a0d DB |
1696 | * |
1697 | * This call may be used with devices that are registered after | |
1698 | * arch init time. It returns a refcounted pointer to the relevant | |
1699 | * spi_master (which the caller must release), or NULL if there is | |
1700 | * no such master registered. | |
1701 | */ | |
1702 | struct spi_master *spi_busnum_to_master(u16 bus_num) | |
1703 | { | |
49dce689 | 1704 | struct device *dev; |
1e9a51dc | 1705 | struct spi_master *master = NULL; |
5ed2c832 | 1706 | |
695794ae | 1707 | dev = class_find_device(&spi_master_class, NULL, &bus_num, |
5ed2c832 DY |
1708 | __spi_master_match); |
1709 | if (dev) | |
1710 | master = container_of(dev, struct spi_master, dev); | |
1711 | /* reference got in class_find_device */ | |
1e9a51dc | 1712 | return master; |
8ae12a0d DB |
1713 | } |
1714 | EXPORT_SYMBOL_GPL(spi_busnum_to_master); | |
1715 | ||
1716 | ||
1717 | /*-------------------------------------------------------------------------*/ | |
1718 | ||
7d077197 DB |
1719 | /* Core methods for SPI master protocol drivers. Some of the |
1720 | * other core methods are currently defined as inline functions. | |
1721 | */ | |
1722 | ||
1723 | /** | |
1724 | * spi_setup - setup SPI mode and clock rate | |
1725 | * @spi: the device whose settings are being modified | |
1726 | * Context: can sleep, and no requests are queued to the device | |
1727 | * | |
1728 | * SPI protocol drivers may need to update the transfer mode if the | |
1729 | * device doesn't work with its default. They may likewise need | |
1730 | * to update clock rates or word sizes from initial values. This function | |
1731 | * changes those settings, and must be called from a context that can sleep. | |
1732 | * Except for SPI_CS_HIGH, which takes effect immediately, the changes take | |
1733 | * effect the next time the device is selected and data is transferred to | |
1734 | * or from it. When this function returns, the spi device is deselected. | |
1735 | * | |
1736 | * Note that this call will fail if the protocol driver specifies an option | |
1737 | * that the underlying controller or its driver does not support. For | |
1738 | * example, not all hardware supports wire transfers using nine bit words, | |
1739 | * LSB-first wire encoding, or active-high chipselects. | |
1740 | */ | |
1741 | int spi_setup(struct spi_device *spi) | |
1742 | { | |
83596fbe | 1743 | unsigned bad_bits, ugly_bits; |
caae070c | 1744 | int status = 0; |
7d077197 | 1745 | |
f477b7fb | 1746 | /* check mode to prevent that DUAL and QUAD set at the same time |
1747 | */ | |
1748 | if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) || | |
1749 | ((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) { | |
1750 | dev_err(&spi->dev, | |
1751 | "setup: can not select dual and quad at the same time\n"); | |
1752 | return -EINVAL; | |
1753 | } | |
1754 | /* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden | |
1755 | */ | |
1756 | if ((spi->mode & SPI_3WIRE) && (spi->mode & | |
1757 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD))) | |
1758 | return -EINVAL; | |
e7db06b5 DB |
1759 | /* help drivers fail *cleanly* when they need options |
1760 | * that aren't supported with their current master | |
1761 | */ | |
1762 | bad_bits = spi->mode & ~spi->master->mode_bits; | |
83596fbe GU |
1763 | ugly_bits = bad_bits & |
1764 | (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD); | |
1765 | if (ugly_bits) { | |
1766 | dev_warn(&spi->dev, | |
1767 | "setup: ignoring unsupported mode bits %x\n", | |
1768 | ugly_bits); | |
1769 | spi->mode &= ~ugly_bits; | |
1770 | bad_bits &= ~ugly_bits; | |
1771 | } | |
e7db06b5 | 1772 | if (bad_bits) { |
eb288a1f | 1773 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
e7db06b5 DB |
1774 | bad_bits); |
1775 | return -EINVAL; | |
1776 | } | |
1777 | ||
7d077197 DB |
1778 | if (!spi->bits_per_word) |
1779 | spi->bits_per_word = 8; | |
1780 | ||
052eb2d4 AL |
1781 | if (!spi->max_speed_hz) |
1782 | spi->max_speed_hz = spi->master->max_speed_hz; | |
1783 | ||
1a7b7ee7 II |
1784 | spi_set_cs(spi, false); |
1785 | ||
caae070c LD |
1786 | if (spi->master->setup) |
1787 | status = spi->master->setup(spi); | |
7d077197 | 1788 | |
5fe5f05e | 1789 | dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", |
7d077197 DB |
1790 | (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), |
1791 | (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", | |
1792 | (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", | |
1793 | (spi->mode & SPI_3WIRE) ? "3wire, " : "", | |
1794 | (spi->mode & SPI_LOOP) ? "loopback, " : "", | |
1795 | spi->bits_per_word, spi->max_speed_hz, | |
1796 | status); | |
1797 | ||
1798 | return status; | |
1799 | } | |
1800 | EXPORT_SYMBOL_GPL(spi_setup); | |
1801 | ||
90808738 | 1802 | static int __spi_validate(struct spi_device *spi, struct spi_message *message) |
cf32b71e ES |
1803 | { |
1804 | struct spi_master *master = spi->master; | |
e6811d1d | 1805 | struct spi_transfer *xfer; |
6ea31293 | 1806 | int w_size; |
cf32b71e | 1807 | |
24a0013a MB |
1808 | if (list_empty(&message->transfers)) |
1809 | return -EINVAL; | |
24a0013a | 1810 | |
cf32b71e ES |
1811 | /* Half-duplex links include original MicroWire, and ones with |
1812 | * only one data pin like SPI_3WIRE (switches direction) or where | |
1813 | * either MOSI or MISO is missing. They can also be caused by | |
1814 | * software limitations. | |
1815 | */ | |
1816 | if ((master->flags & SPI_MASTER_HALF_DUPLEX) | |
1817 | || (spi->mode & SPI_3WIRE)) { | |
cf32b71e ES |
1818 | unsigned flags = master->flags; |
1819 | ||
1820 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
1821 | if (xfer->rx_buf && xfer->tx_buf) | |
1822 | return -EINVAL; | |
1823 | if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) | |
1824 | return -EINVAL; | |
1825 | if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) | |
1826 | return -EINVAL; | |
1827 | } | |
1828 | } | |
1829 | ||
e6811d1d | 1830 | /** |
059b8ffe LD |
1831 | * Set transfer bits_per_word and max speed as spi device default if |
1832 | * it is not set for this transfer. | |
f477b7fb | 1833 | * Set transfer tx_nbits and rx_nbits as single transfer default |
1834 | * (SPI_NBITS_SINGLE) if it is not set for this transfer. | |
e6811d1d LD |
1835 | */ |
1836 | list_for_each_entry(xfer, &message->transfers, transfer_list) { | |
078726ce | 1837 | message->frame_length += xfer->len; |
e6811d1d LD |
1838 | if (!xfer->bits_per_word) |
1839 | xfer->bits_per_word = spi->bits_per_word; | |
a6f87fad AL |
1840 | |
1841 | if (!xfer->speed_hz) | |
059b8ffe | 1842 | xfer->speed_hz = spi->max_speed_hz; |
a6f87fad AL |
1843 | |
1844 | if (master->max_speed_hz && | |
1845 | xfer->speed_hz > master->max_speed_hz) | |
1846 | xfer->speed_hz = master->max_speed_hz; | |
56ede94a | 1847 | |
543bb255 SW |
1848 | if (master->bits_per_word_mask) { |
1849 | /* Only 32 bits fit in the mask */ | |
1850 | if (xfer->bits_per_word > 32) | |
1851 | return -EINVAL; | |
1852 | if (!(master->bits_per_word_mask & | |
1853 | BIT(xfer->bits_per_word - 1))) | |
1854 | return -EINVAL; | |
1855 | } | |
a2fd4f9f | 1856 | |
4d94bd21 II |
1857 | /* |
1858 | * SPI transfer length should be multiple of SPI word size | |
1859 | * where SPI word size should be power-of-two multiple | |
1860 | */ | |
1861 | if (xfer->bits_per_word <= 8) | |
1862 | w_size = 1; | |
1863 | else if (xfer->bits_per_word <= 16) | |
1864 | w_size = 2; | |
1865 | else | |
1866 | w_size = 4; | |
1867 | ||
4d94bd21 | 1868 | /* No partial transfers accepted */ |
6ea31293 | 1869 | if (xfer->len % w_size) |
4d94bd21 II |
1870 | return -EINVAL; |
1871 | ||
a2fd4f9f MB |
1872 | if (xfer->speed_hz && master->min_speed_hz && |
1873 | xfer->speed_hz < master->min_speed_hz) | |
1874 | return -EINVAL; | |
f477b7fb | 1875 | |
1876 | if (xfer->tx_buf && !xfer->tx_nbits) | |
1877 | xfer->tx_nbits = SPI_NBITS_SINGLE; | |
1878 | if (xfer->rx_buf && !xfer->rx_nbits) | |
1879 | xfer->rx_nbits = SPI_NBITS_SINGLE; | |
1880 | /* check transfer tx/rx_nbits: | |
1afd9989 GU |
1881 | * 1. check the value matches one of single, dual and quad |
1882 | * 2. check tx/rx_nbits match the mode in spi_device | |
f477b7fb | 1883 | */ |
db90a441 SP |
1884 | if (xfer->tx_buf) { |
1885 | if (xfer->tx_nbits != SPI_NBITS_SINGLE && | |
1886 | xfer->tx_nbits != SPI_NBITS_DUAL && | |
1887 | xfer->tx_nbits != SPI_NBITS_QUAD) | |
1888 | return -EINVAL; | |
1889 | if ((xfer->tx_nbits == SPI_NBITS_DUAL) && | |
1890 | !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) | |
1891 | return -EINVAL; | |
1892 | if ((xfer->tx_nbits == SPI_NBITS_QUAD) && | |
1893 | !(spi->mode & SPI_TX_QUAD)) | |
1894 | return -EINVAL; | |
db90a441 | 1895 | } |
f477b7fb | 1896 | /* check transfer rx_nbits */ |
db90a441 SP |
1897 | if (xfer->rx_buf) { |
1898 | if (xfer->rx_nbits != SPI_NBITS_SINGLE && | |
1899 | xfer->rx_nbits != SPI_NBITS_DUAL && | |
1900 | xfer->rx_nbits != SPI_NBITS_QUAD) | |
1901 | return -EINVAL; | |
1902 | if ((xfer->rx_nbits == SPI_NBITS_DUAL) && | |
1903 | !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) | |
1904 | return -EINVAL; | |
1905 | if ((xfer->rx_nbits == SPI_NBITS_QUAD) && | |
1906 | !(spi->mode & SPI_RX_QUAD)) | |
1907 | return -EINVAL; | |
db90a441 | 1908 | } |
e6811d1d LD |
1909 | } |
1910 | ||
cf32b71e | 1911 | message->status = -EINPROGRESS; |
90808738 MB |
1912 | |
1913 | return 0; | |
1914 | } | |
1915 | ||
1916 | static int __spi_async(struct spi_device *spi, struct spi_message *message) | |
1917 | { | |
1918 | struct spi_master *master = spi->master; | |
1919 | ||
1920 | message->spi = spi; | |
1921 | ||
1922 | trace_spi_message_submit(message); | |
1923 | ||
cf32b71e ES |
1924 | return master->transfer(spi, message); |
1925 | } | |
1926 | ||
568d0697 DB |
1927 | /** |
1928 | * spi_async - asynchronous SPI transfer | |
1929 | * @spi: device with which data will be exchanged | |
1930 | * @message: describes the data transfers, including completion callback | |
1931 | * Context: any (irqs may be blocked, etc) | |
1932 | * | |
1933 | * This call may be used in_irq and other contexts which can't sleep, | |
1934 | * as well as from task contexts which can sleep. | |
1935 | * | |
1936 | * The completion callback is invoked in a context which can't sleep. | |
1937 | * Before that invocation, the value of message->status is undefined. | |
1938 | * When the callback is issued, message->status holds either zero (to | |
1939 | * indicate complete success) or a negative error code. After that | |
1940 | * callback returns, the driver which issued the transfer request may | |
1941 | * deallocate the associated memory; it's no longer in use by any SPI | |
1942 | * core or controller driver code. | |
1943 | * | |
1944 | * Note that although all messages to a spi_device are handled in | |
1945 | * FIFO order, messages may go to different devices in other orders. | |
1946 | * Some device might be higher priority, or have various "hard" access | |
1947 | * time requirements, for example. | |
1948 | * | |
1949 | * On detection of any fault during the transfer, processing of | |
1950 | * the entire message is aborted, and the device is deselected. | |
1951 | * Until returning from the associated message completion callback, | |
1952 | * no other spi_message queued to that device will be processed. | |
1953 | * (This rule applies equally to all the synchronous transfer calls, | |
1954 | * which are wrappers around this core asynchronous primitive.) | |
1955 | */ | |
1956 | int spi_async(struct spi_device *spi, struct spi_message *message) | |
1957 | { | |
1958 | struct spi_master *master = spi->master; | |
cf32b71e ES |
1959 | int ret; |
1960 | unsigned long flags; | |
568d0697 | 1961 | |
90808738 MB |
1962 | ret = __spi_validate(spi, message); |
1963 | if (ret != 0) | |
1964 | return ret; | |
1965 | ||
cf32b71e | 1966 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
568d0697 | 1967 | |
cf32b71e ES |
1968 | if (master->bus_lock_flag) |
1969 | ret = -EBUSY; | |
1970 | else | |
1971 | ret = __spi_async(spi, message); | |
568d0697 | 1972 | |
cf32b71e ES |
1973 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); |
1974 | ||
1975 | return ret; | |
568d0697 DB |
1976 | } |
1977 | EXPORT_SYMBOL_GPL(spi_async); | |
1978 | ||
cf32b71e ES |
1979 | /** |
1980 | * spi_async_locked - version of spi_async with exclusive bus usage | |
1981 | * @spi: device with which data will be exchanged | |
1982 | * @message: describes the data transfers, including completion callback | |
1983 | * Context: any (irqs may be blocked, etc) | |
1984 | * | |
1985 | * This call may be used in_irq and other contexts which can't sleep, | |
1986 | * as well as from task contexts which can sleep. | |
1987 | * | |
1988 | * The completion callback is invoked in a context which can't sleep. | |
1989 | * Before that invocation, the value of message->status is undefined. | |
1990 | * When the callback is issued, message->status holds either zero (to | |
1991 | * indicate complete success) or a negative error code. After that | |
1992 | * callback returns, the driver which issued the transfer request may | |
1993 | * deallocate the associated memory; it's no longer in use by any SPI | |
1994 | * core or controller driver code. | |
1995 | * | |
1996 | * Note that although all messages to a spi_device are handled in | |
1997 | * FIFO order, messages may go to different devices in other orders. | |
1998 | * Some device might be higher priority, or have various "hard" access | |
1999 | * time requirements, for example. | |
2000 | * | |
2001 | * On detection of any fault during the transfer, processing of | |
2002 | * the entire message is aborted, and the device is deselected. | |
2003 | * Until returning from the associated message completion callback, | |
2004 | * no other spi_message queued to that device will be processed. | |
2005 | * (This rule applies equally to all the synchronous transfer calls, | |
2006 | * which are wrappers around this core asynchronous primitive.) | |
2007 | */ | |
2008 | int spi_async_locked(struct spi_device *spi, struct spi_message *message) | |
2009 | { | |
2010 | struct spi_master *master = spi->master; | |
2011 | int ret; | |
2012 | unsigned long flags; | |
2013 | ||
90808738 MB |
2014 | ret = __spi_validate(spi, message); |
2015 | if (ret != 0) | |
2016 | return ret; | |
2017 | ||
cf32b71e ES |
2018 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); |
2019 | ||
2020 | ret = __spi_async(spi, message); | |
2021 | ||
2022 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2023 | ||
2024 | return ret; | |
2025 | ||
2026 | } | |
2027 | EXPORT_SYMBOL_GPL(spi_async_locked); | |
2028 | ||
7d077197 DB |
2029 | |
2030 | /*-------------------------------------------------------------------------*/ | |
2031 | ||
2032 | /* Utility methods for SPI master protocol drivers, layered on | |
2033 | * top of the core. Some other utility methods are defined as | |
2034 | * inline functions. | |
2035 | */ | |
2036 | ||
5d870c8e AM |
2037 | static void spi_complete(void *arg) |
2038 | { | |
2039 | complete(arg); | |
2040 | } | |
2041 | ||
cf32b71e ES |
2042 | static int __spi_sync(struct spi_device *spi, struct spi_message *message, |
2043 | int bus_locked) | |
2044 | { | |
2045 | DECLARE_COMPLETION_ONSTACK(done); | |
2046 | int status; | |
2047 | struct spi_master *master = spi->master; | |
0461a414 MB |
2048 | unsigned long flags; |
2049 | ||
2050 | status = __spi_validate(spi, message); | |
2051 | if (status != 0) | |
2052 | return status; | |
cf32b71e ES |
2053 | |
2054 | message->complete = spi_complete; | |
2055 | message->context = &done; | |
0461a414 | 2056 | message->spi = spi; |
cf32b71e ES |
2057 | |
2058 | if (!bus_locked) | |
2059 | mutex_lock(&master->bus_lock_mutex); | |
2060 | ||
0461a414 MB |
2061 | /* If we're not using the legacy transfer method then we will |
2062 | * try to transfer in the calling context so special case. | |
2063 | * This code would be less tricky if we could remove the | |
2064 | * support for driver implemented message queues. | |
2065 | */ | |
2066 | if (master->transfer == spi_queued_transfer) { | |
2067 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2068 | ||
2069 | trace_spi_message_submit(message); | |
2070 | ||
2071 | status = __spi_queued_transfer(spi, message, false); | |
2072 | ||
2073 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2074 | } else { | |
2075 | status = spi_async_locked(spi, message); | |
2076 | } | |
cf32b71e ES |
2077 | |
2078 | if (!bus_locked) | |
2079 | mutex_unlock(&master->bus_lock_mutex); | |
2080 | ||
2081 | if (status == 0) { | |
0461a414 MB |
2082 | /* Push out the messages in the calling context if we |
2083 | * can. | |
2084 | */ | |
2085 | if (master->transfer == spi_queued_transfer) | |
fc9e0f71 | 2086 | __spi_pump_messages(master, false); |
0461a414 | 2087 | |
cf32b71e ES |
2088 | wait_for_completion(&done); |
2089 | status = message->status; | |
2090 | } | |
2091 | message->context = NULL; | |
2092 | return status; | |
2093 | } | |
2094 | ||
8ae12a0d DB |
2095 | /** |
2096 | * spi_sync - blocking/synchronous SPI data transfers | |
2097 | * @spi: device with which data will be exchanged | |
2098 | * @message: describes the data transfers | |
33e34dc6 | 2099 | * Context: can sleep |
8ae12a0d DB |
2100 | * |
2101 | * This call may only be used from a context that may sleep. The sleep | |
2102 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2103 | * drivers may DMA directly into and out of the message buffers. | |
2104 | * | |
2105 | * Note that the SPI device's chip select is active during the message, | |
2106 | * and then is normally disabled between messages. Drivers for some | |
2107 | * frequently-used devices may want to minimize costs of selecting a chip, | |
2108 | * by leaving it selected in anticipation that the next message will go | |
2109 | * to the same chip. (That may increase power usage.) | |
2110 | * | |
0c868461 DB |
2111 | * Also, the caller is guaranteeing that the memory associated with the |
2112 | * message will not be freed before this call returns. | |
2113 | * | |
9b938b74 | 2114 | * It returns zero on success, else a negative error code. |
8ae12a0d DB |
2115 | */ |
2116 | int spi_sync(struct spi_device *spi, struct spi_message *message) | |
2117 | { | |
cf32b71e | 2118 | return __spi_sync(spi, message, 0); |
8ae12a0d DB |
2119 | } |
2120 | EXPORT_SYMBOL_GPL(spi_sync); | |
2121 | ||
cf32b71e ES |
2122 | /** |
2123 | * spi_sync_locked - version of spi_sync with exclusive bus usage | |
2124 | * @spi: device with which data will be exchanged | |
2125 | * @message: describes the data transfers | |
2126 | * Context: can sleep | |
2127 | * | |
2128 | * This call may only be used from a context that may sleep. The sleep | |
2129 | * is non-interruptible, and has no timeout. Low-overhead controller | |
2130 | * drivers may DMA directly into and out of the message buffers. | |
2131 | * | |
2132 | * This call should be used by drivers that require exclusive access to the | |
25985edc | 2133 | * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must |
cf32b71e ES |
2134 | * be released by a spi_bus_unlock call when the exclusive access is over. |
2135 | * | |
2136 | * It returns zero on success, else a negative error code. | |
2137 | */ | |
2138 | int spi_sync_locked(struct spi_device *spi, struct spi_message *message) | |
2139 | { | |
2140 | return __spi_sync(spi, message, 1); | |
2141 | } | |
2142 | EXPORT_SYMBOL_GPL(spi_sync_locked); | |
2143 | ||
2144 | /** | |
2145 | * spi_bus_lock - obtain a lock for exclusive SPI bus usage | |
2146 | * @master: SPI bus master that should be locked for exclusive bus access | |
2147 | * Context: can sleep | |
2148 | * | |
2149 | * This call may only be used from a context that may sleep. The sleep | |
2150 | * is non-interruptible, and has no timeout. | |
2151 | * | |
2152 | * This call should be used by drivers that require exclusive access to the | |
2153 | * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the | |
2154 | * exclusive access is over. Data transfer must be done by spi_sync_locked | |
2155 | * and spi_async_locked calls when the SPI bus lock is held. | |
2156 | * | |
2157 | * It returns zero on success, else a negative error code. | |
2158 | */ | |
2159 | int spi_bus_lock(struct spi_master *master) | |
2160 | { | |
2161 | unsigned long flags; | |
2162 | ||
2163 | mutex_lock(&master->bus_lock_mutex); | |
2164 | ||
2165 | spin_lock_irqsave(&master->bus_lock_spinlock, flags); | |
2166 | master->bus_lock_flag = 1; | |
2167 | spin_unlock_irqrestore(&master->bus_lock_spinlock, flags); | |
2168 | ||
2169 | /* mutex remains locked until spi_bus_unlock is called */ | |
2170 | ||
2171 | return 0; | |
2172 | } | |
2173 | EXPORT_SYMBOL_GPL(spi_bus_lock); | |
2174 | ||
2175 | /** | |
2176 | * spi_bus_unlock - release the lock for exclusive SPI bus usage | |
2177 | * @master: SPI bus master that was locked for exclusive bus access | |
2178 | * Context: can sleep | |
2179 | * | |
2180 | * This call may only be used from a context that may sleep. The sleep | |
2181 | * is non-interruptible, and has no timeout. | |
2182 | * | |
2183 | * This call releases an SPI bus lock previously obtained by an spi_bus_lock | |
2184 | * call. | |
2185 | * | |
2186 | * It returns zero on success, else a negative error code. | |
2187 | */ | |
2188 | int spi_bus_unlock(struct spi_master *master) | |
2189 | { | |
2190 | master->bus_lock_flag = 0; | |
2191 | ||
2192 | mutex_unlock(&master->bus_lock_mutex); | |
2193 | ||
2194 | return 0; | |
2195 | } | |
2196 | EXPORT_SYMBOL_GPL(spi_bus_unlock); | |
2197 | ||
a9948b61 | 2198 | /* portable code must never pass more than 32 bytes */ |
5fe5f05e | 2199 | #define SPI_BUFSIZ max(32, SMP_CACHE_BYTES) |
8ae12a0d DB |
2200 | |
2201 | static u8 *buf; | |
2202 | ||
2203 | /** | |
2204 | * spi_write_then_read - SPI synchronous write followed by read | |
2205 | * @spi: device with which data will be exchanged | |
2206 | * @txbuf: data to be written (need not be dma-safe) | |
2207 | * @n_tx: size of txbuf, in bytes | |
27570497 JP |
2208 | * @rxbuf: buffer into which data will be read (need not be dma-safe) |
2209 | * @n_rx: size of rxbuf, in bytes | |
33e34dc6 | 2210 | * Context: can sleep |
8ae12a0d DB |
2211 | * |
2212 | * This performs a half duplex MicroWire style transaction with the | |
2213 | * device, sending txbuf and then reading rxbuf. The return value | |
2214 | * is zero for success, else a negative errno status code. | |
b885244e | 2215 | * This call may only be used from a context that may sleep. |
8ae12a0d | 2216 | * |
0c868461 | 2217 | * Parameters to this routine are always copied using a small buffer; |
33e34dc6 DB |
2218 | * portable code should never use this for more than 32 bytes. |
2219 | * Performance-sensitive or bulk transfer code should instead use | |
0c868461 | 2220 | * spi_{async,sync}() calls with dma-safe buffers. |
8ae12a0d DB |
2221 | */ |
2222 | int spi_write_then_read(struct spi_device *spi, | |
0c4a1590 MB |
2223 | const void *txbuf, unsigned n_tx, |
2224 | void *rxbuf, unsigned n_rx) | |
8ae12a0d | 2225 | { |
068f4070 | 2226 | static DEFINE_MUTEX(lock); |
8ae12a0d DB |
2227 | |
2228 | int status; | |
2229 | struct spi_message message; | |
bdff549e | 2230 | struct spi_transfer x[2]; |
8ae12a0d DB |
2231 | u8 *local_buf; |
2232 | ||
b3a223ee MB |
2233 | /* Use preallocated DMA-safe buffer if we can. We can't avoid |
2234 | * copying here, (as a pure convenience thing), but we can | |
2235 | * keep heap costs out of the hot path unless someone else is | |
2236 | * using the pre-allocated buffer or the transfer is too large. | |
8ae12a0d | 2237 | */ |
b3a223ee | 2238 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { |
2cd94c8a MB |
2239 | local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), |
2240 | GFP_KERNEL | GFP_DMA); | |
b3a223ee MB |
2241 | if (!local_buf) |
2242 | return -ENOMEM; | |
2243 | } else { | |
2244 | local_buf = buf; | |
2245 | } | |
8ae12a0d | 2246 | |
8275c642 | 2247 | spi_message_init(&message); |
5fe5f05e | 2248 | memset(x, 0, sizeof(x)); |
bdff549e DB |
2249 | if (n_tx) { |
2250 | x[0].len = n_tx; | |
2251 | spi_message_add_tail(&x[0], &message); | |
2252 | } | |
2253 | if (n_rx) { | |
2254 | x[1].len = n_rx; | |
2255 | spi_message_add_tail(&x[1], &message); | |
2256 | } | |
8275c642 | 2257 | |
8ae12a0d | 2258 | memcpy(local_buf, txbuf, n_tx); |
bdff549e DB |
2259 | x[0].tx_buf = local_buf; |
2260 | x[1].rx_buf = local_buf + n_tx; | |
8ae12a0d DB |
2261 | |
2262 | /* do the i/o */ | |
8ae12a0d | 2263 | status = spi_sync(spi, &message); |
9b938b74 | 2264 | if (status == 0) |
bdff549e | 2265 | memcpy(rxbuf, x[1].rx_buf, n_rx); |
8ae12a0d | 2266 | |
bdff549e | 2267 | if (x[0].tx_buf == buf) |
068f4070 | 2268 | mutex_unlock(&lock); |
8ae12a0d DB |
2269 | else |
2270 | kfree(local_buf); | |
2271 | ||
2272 | return status; | |
2273 | } | |
2274 | EXPORT_SYMBOL_GPL(spi_write_then_read); | |
2275 | ||
2276 | /*-------------------------------------------------------------------------*/ | |
2277 | ||
ce79d54a PA |
2278 | #if IS_ENABLED(CONFIG_OF_DYNAMIC) |
2279 | static int __spi_of_device_match(struct device *dev, void *data) | |
2280 | { | |
2281 | return dev->of_node == data; | |
2282 | } | |
2283 | ||
2284 | /* must call put_device() when done with returned spi_device device */ | |
2285 | static struct spi_device *of_find_spi_device_by_node(struct device_node *node) | |
2286 | { | |
2287 | struct device *dev = bus_find_device(&spi_bus_type, NULL, node, | |
2288 | __spi_of_device_match); | |
2289 | return dev ? to_spi_device(dev) : NULL; | |
2290 | } | |
2291 | ||
2292 | static int __spi_of_master_match(struct device *dev, const void *data) | |
2293 | { | |
2294 | return dev->of_node == data; | |
2295 | } | |
2296 | ||
2297 | /* the spi masters are not using spi_bus, so we find it with another way */ | |
2298 | static struct spi_master *of_find_spi_master_by_node(struct device_node *node) | |
2299 | { | |
2300 | struct device *dev; | |
2301 | ||
2302 | dev = class_find_device(&spi_master_class, NULL, node, | |
2303 | __spi_of_master_match); | |
2304 | if (!dev) | |
2305 | return NULL; | |
2306 | ||
2307 | /* reference got in class_find_device */ | |
2308 | return container_of(dev, struct spi_master, dev); | |
2309 | } | |
2310 | ||
2311 | static int of_spi_notify(struct notifier_block *nb, unsigned long action, | |
2312 | void *arg) | |
2313 | { | |
2314 | struct of_reconfig_data *rd = arg; | |
2315 | struct spi_master *master; | |
2316 | struct spi_device *spi; | |
2317 | ||
2318 | switch (of_reconfig_get_state_change(action, arg)) { | |
2319 | case OF_RECONFIG_CHANGE_ADD: | |
2320 | master = of_find_spi_master_by_node(rd->dn->parent); | |
2321 | if (master == NULL) | |
2322 | return NOTIFY_OK; /* not for us */ | |
2323 | ||
2324 | spi = of_register_spi_device(master, rd->dn); | |
2325 | put_device(&master->dev); | |
2326 | ||
2327 | if (IS_ERR(spi)) { | |
2328 | pr_err("%s: failed to create for '%s'\n", | |
2329 | __func__, rd->dn->full_name); | |
2330 | return notifier_from_errno(PTR_ERR(spi)); | |
2331 | } | |
2332 | break; | |
2333 | ||
2334 | case OF_RECONFIG_CHANGE_REMOVE: | |
2335 | /* find our device by node */ | |
2336 | spi = of_find_spi_device_by_node(rd->dn); | |
2337 | if (spi == NULL) | |
2338 | return NOTIFY_OK; /* no? not meant for us */ | |
2339 | ||
2340 | /* unregister takes one ref away */ | |
2341 | spi_unregister_device(spi); | |
2342 | ||
2343 | /* and put the reference of the find */ | |
2344 | put_device(&spi->dev); | |
2345 | break; | |
2346 | } | |
2347 | ||
2348 | return NOTIFY_OK; | |
2349 | } | |
2350 | ||
2351 | static struct notifier_block spi_of_notifier = { | |
2352 | .notifier_call = of_spi_notify, | |
2353 | }; | |
2354 | #else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2355 | extern struct notifier_block spi_of_notifier; | |
2356 | #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ | |
2357 | ||
8ae12a0d DB |
2358 | static int __init spi_init(void) |
2359 | { | |
b885244e DB |
2360 | int status; |
2361 | ||
e94b1766 | 2362 | buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); |
b885244e DB |
2363 | if (!buf) { |
2364 | status = -ENOMEM; | |
2365 | goto err0; | |
2366 | } | |
2367 | ||
2368 | status = bus_register(&spi_bus_type); | |
2369 | if (status < 0) | |
2370 | goto err1; | |
8ae12a0d | 2371 | |
b885244e DB |
2372 | status = class_register(&spi_master_class); |
2373 | if (status < 0) | |
2374 | goto err2; | |
ce79d54a | 2375 | |
5267720e | 2376 | if (IS_ENABLED(CONFIG_OF_DYNAMIC)) |
ce79d54a PA |
2377 | WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); |
2378 | ||
8ae12a0d | 2379 | return 0; |
b885244e DB |
2380 | |
2381 | err2: | |
2382 | bus_unregister(&spi_bus_type); | |
2383 | err1: | |
2384 | kfree(buf); | |
2385 | buf = NULL; | |
2386 | err0: | |
2387 | return status; | |
8ae12a0d | 2388 | } |
b885244e | 2389 | |
8ae12a0d DB |
2390 | /* board_info is normally registered in arch_initcall(), |
2391 | * but even essential drivers wait till later | |
b885244e DB |
2392 | * |
2393 | * REVISIT only boardinfo really needs static linking. the rest (device and | |
2394 | * driver registration) _could_ be dynamically linked (modular) ... costs | |
2395 | * include needing to have boardinfo data structures be much more public. | |
8ae12a0d | 2396 | */ |
673c0c00 | 2397 | postcore_initcall(spi_init); |
8ae12a0d | 2398 |