Commit | Line | Data |
---|---|---|
0c2498f1 SH |
1 | /* |
2 | * Generic pwmlib implementation | |
3 | * | |
4 | * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> | |
f051c466 | 5 | * Copyright (C) 2011-2012 Avionic Design GmbH |
0c2498f1 SH |
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, or (at your option) | |
10 | * 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; see the file COPYING. If not, write to | |
19 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/pwm.h> | |
f051c466 | 24 | #include <linux/radix-tree.h> |
0c2498f1 SH |
25 | #include <linux/list.h> |
26 | #include <linux/mutex.h> | |
27 | #include <linux/err.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/device.h> | |
62099abf TR |
30 | #include <linux/debugfs.h> |
31 | #include <linux/seq_file.h> | |
0c2498f1 | 32 | |
208be769 | 33 | #include <dt-bindings/pwm/pwm.h> |
0c2498f1 | 34 | |
208be769 | 35 | #define MAX_PWMS 1024 |
83af2402 | 36 | |
8138d2dd TR |
37 | static DEFINE_MUTEX(pwm_lookup_lock); |
38 | static LIST_HEAD(pwm_lookup_list); | |
0c2498f1 | 39 | static DEFINE_MUTEX(pwm_lock); |
f051c466 TR |
40 | static LIST_HEAD(pwm_chips); |
41 | static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); | |
42 | static RADIX_TREE(pwm_tree, GFP_KERNEL); | |
0c2498f1 | 43 | |
f051c466 | 44 | static struct pwm_device *pwm_to_device(unsigned int pwm) |
0c2498f1 | 45 | { |
f051c466 TR |
46 | return radix_tree_lookup(&pwm_tree, pwm); |
47 | } | |
48 | ||
49 | static int alloc_pwms(int pwm, unsigned int count) | |
50 | { | |
51 | unsigned int from = 0; | |
52 | unsigned int start; | |
53 | ||
54 | if (pwm >= MAX_PWMS) | |
55 | return -EINVAL; | |
56 | ||
57 | if (pwm >= 0) | |
58 | from = pwm; | |
0c2498f1 | 59 | |
f051c466 TR |
60 | start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
61 | count, 0); | |
62 | ||
63 | if (pwm >= 0 && start != pwm) | |
64 | return -EEXIST; | |
65 | ||
66 | if (start + count > MAX_PWMS) | |
67 | return -ENOSPC; | |
68 | ||
69 | return start; | |
70 | } | |
71 | ||
72 | static void free_pwms(struct pwm_chip *chip) | |
73 | { | |
74 | unsigned int i; | |
75 | ||
76 | for (i = 0; i < chip->npwm; i++) { | |
77 | struct pwm_device *pwm = &chip->pwms[i]; | |
78 | radix_tree_delete(&pwm_tree, pwm->pwm); | |
0c2498f1 SH |
79 | } |
80 | ||
f051c466 TR |
81 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
82 | ||
83 | kfree(chip->pwms); | |
84 | chip->pwms = NULL; | |
85 | } | |
86 | ||
8138d2dd TR |
87 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
88 | { | |
89 | struct pwm_chip *chip; | |
90 | ||
91 | if (!name) | |
92 | return NULL; | |
93 | ||
94 | mutex_lock(&pwm_lock); | |
95 | ||
96 | list_for_each_entry(chip, &pwm_chips, list) { | |
97 | const char *chip_name = dev_name(chip->dev); | |
98 | ||
99 | if (chip_name && strcmp(chip_name, name) == 0) { | |
100 | mutex_unlock(&pwm_lock); | |
101 | return chip; | |
102 | } | |
103 | } | |
104 | ||
105 | mutex_unlock(&pwm_lock); | |
106 | ||
107 | return NULL; | |
108 | } | |
109 | ||
f051c466 TR |
110 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
111 | { | |
112 | int err; | |
113 | ||
114 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
115 | return -EBUSY; | |
116 | ||
117 | if (!try_module_get(pwm->chip->ops->owner)) | |
118 | return -ENODEV; | |
119 | ||
120 | if (pwm->chip->ops->request) { | |
121 | err = pwm->chip->ops->request(pwm->chip, pwm); | |
122 | if (err) { | |
123 | module_put(pwm->chip->ops->owner); | |
124 | return err; | |
125 | } | |
126 | } | |
127 | ||
128 | set_bit(PWMF_REQUESTED, &pwm->flags); | |
129 | pwm->label = label; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
83af2402 PA |
134 | struct pwm_device * |
135 | of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) | |
136 | { | |
137 | struct pwm_device *pwm; | |
138 | ||
139 | if (pc->of_pwm_n_cells < 3) | |
140 | return ERR_PTR(-EINVAL); | |
141 | ||
142 | if (args->args[0] >= pc->npwm) | |
143 | return ERR_PTR(-EINVAL); | |
144 | ||
145 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
146 | if (IS_ERR(pwm)) | |
147 | return pwm; | |
148 | ||
149 | pwm_set_period(pwm, args->args[1]); | |
150 | ||
208be769 | 151 | if (args->args[2] & PWM_POLARITY_INVERTED) |
83af2402 PA |
152 | pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); |
153 | else | |
154 | pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); | |
155 | ||
156 | return pwm; | |
157 | } | |
417328c3 | 158 | EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
83af2402 | 159 | |
e50d3523 SK |
160 | static struct pwm_device * |
161 | of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) | |
7299ab70 TR |
162 | { |
163 | struct pwm_device *pwm; | |
164 | ||
165 | if (pc->of_pwm_n_cells < 2) | |
166 | return ERR_PTR(-EINVAL); | |
167 | ||
168 | if (args->args[0] >= pc->npwm) | |
169 | return ERR_PTR(-EINVAL); | |
170 | ||
171 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
172 | if (IS_ERR(pwm)) | |
173 | return pwm; | |
174 | ||
175 | pwm_set_period(pwm, args->args[1]); | |
176 | ||
177 | return pwm; | |
178 | } | |
179 | ||
dfeb86ec | 180 | static void of_pwmchip_add(struct pwm_chip *chip) |
7299ab70 TR |
181 | { |
182 | if (!chip->dev || !chip->dev->of_node) | |
183 | return; | |
184 | ||
185 | if (!chip->of_xlate) { | |
186 | chip->of_xlate = of_pwm_simple_xlate; | |
187 | chip->of_pwm_n_cells = 2; | |
188 | } | |
189 | ||
190 | of_node_get(chip->dev->of_node); | |
191 | } | |
192 | ||
dfeb86ec | 193 | static void of_pwmchip_remove(struct pwm_chip *chip) |
7299ab70 | 194 | { |
8d6cc073 | 195 | if (chip->dev) |
7299ab70 TR |
196 | of_node_put(chip->dev->of_node); |
197 | } | |
198 | ||
f051c466 TR |
199 | /** |
200 | * pwm_set_chip_data() - set private chip data for a PWM | |
201 | * @pwm: PWM device | |
202 | * @data: pointer to chip-specific data | |
04883802 TR |
203 | * |
204 | * Returns: 0 on success or a negative error code on failure. | |
f051c466 TR |
205 | */ |
206 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) | |
207 | { | |
208 | if (!pwm) | |
209 | return -EINVAL; | |
210 | ||
211 | pwm->chip_data = data; | |
212 | ||
213 | return 0; | |
214 | } | |
928c4477 | 215 | EXPORT_SYMBOL_GPL(pwm_set_chip_data); |
f051c466 TR |
216 | |
217 | /** | |
218 | * pwm_get_chip_data() - get private chip data for a PWM | |
219 | * @pwm: PWM device | |
04883802 TR |
220 | * |
221 | * Returns: A pointer to the chip-private data for the PWM device. | |
f051c466 TR |
222 | */ |
223 | void *pwm_get_chip_data(struct pwm_device *pwm) | |
224 | { | |
225 | return pwm ? pwm->chip_data : NULL; | |
0c2498f1 | 226 | } |
928c4477 | 227 | EXPORT_SYMBOL_GPL(pwm_get_chip_data); |
0c2498f1 SH |
228 | |
229 | /** | |
b6a00fae | 230 | * pwmchip_add_with_polarity() - register a new PWM chip |
0c2498f1 | 231 | * @chip: the PWM chip to add |
b6a00fae | 232 | * @polarity: initial polarity of PWM channels |
f051c466 TR |
233 | * |
234 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
b6a00fae TK |
235 | * will be used. The initial polarity for all channels is specified by the |
236 | * @polarity parameter. | |
04883802 TR |
237 | * |
238 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 | 239 | */ |
b6a00fae TK |
240 | int pwmchip_add_with_polarity(struct pwm_chip *chip, |
241 | enum pwm_polarity polarity) | |
0c2498f1 SH |
242 | { |
243 | struct pwm_device *pwm; | |
f051c466 TR |
244 | unsigned int i; |
245 | int ret; | |
0c2498f1 | 246 | |
f051c466 | 247 | if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
533acc0e | 248 | !chip->ops->enable || !chip->ops->disable || !chip->npwm) |
f051c466 | 249 | return -EINVAL; |
0c2498f1 SH |
250 | |
251 | mutex_lock(&pwm_lock); | |
252 | ||
f051c466 TR |
253 | ret = alloc_pwms(chip->base, chip->npwm); |
254 | if (ret < 0) | |
255 | goto out; | |
256 | ||
257 | chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); | |
258 | if (!chip->pwms) { | |
259 | ret = -ENOMEM; | |
0c2498f1 SH |
260 | goto out; |
261 | } | |
262 | ||
f051c466 TR |
263 | chip->base = ret; |
264 | ||
265 | for (i = 0; i < chip->npwm; i++) { | |
266 | pwm = &chip->pwms[i]; | |
267 | ||
268 | pwm->chip = chip; | |
269 | pwm->pwm = chip->base + i; | |
270 | pwm->hwpwm = i; | |
b6a00fae | 271 | pwm->polarity = polarity; |
0c2498f1 | 272 | |
f051c466 TR |
273 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
274 | } | |
275 | ||
276 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
277 | ||
278 | INIT_LIST_HEAD(&chip->list); | |
279 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 280 | |
f051c466 TR |
281 | ret = 0; |
282 | ||
7299ab70 TR |
283 | if (IS_ENABLED(CONFIG_OF)) |
284 | of_pwmchip_add(chip); | |
285 | ||
76abbdde HS |
286 | pwmchip_sysfs_export(chip); |
287 | ||
f051c466 TR |
288 | out: |
289 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
290 | return ret; |
291 | } | |
b6a00fae TK |
292 | EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); |
293 | ||
294 | /** | |
295 | * pwmchip_add() - register a new PWM chip | |
296 | * @chip: the PWM chip to add | |
297 | * | |
298 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
299 | * will be used. The initial polarity for all channels is normal. | |
04883802 TR |
300 | * |
301 | * Returns: 0 on success or a negative error code on failure. | |
b6a00fae TK |
302 | */ |
303 | int pwmchip_add(struct pwm_chip *chip) | |
304 | { | |
305 | return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); | |
306 | } | |
0c2498f1 SH |
307 | EXPORT_SYMBOL_GPL(pwmchip_add); |
308 | ||
309 | /** | |
310 | * pwmchip_remove() - remove a PWM chip | |
311 | * @chip: the PWM chip to remove | |
312 | * | |
313 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
314 | * a PWM device that is still requested. | |
04883802 TR |
315 | * |
316 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
317 | */ |
318 | int pwmchip_remove(struct pwm_chip *chip) | |
319 | { | |
f051c466 | 320 | unsigned int i; |
0c2498f1 SH |
321 | int ret = 0; |
322 | ||
323 | mutex_lock(&pwm_lock); | |
324 | ||
f051c466 TR |
325 | for (i = 0; i < chip->npwm; i++) { |
326 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 327 | |
f051c466 TR |
328 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
329 | ret = -EBUSY; | |
330 | goto out; | |
331 | } | |
0c2498f1 SH |
332 | } |
333 | ||
f051c466 | 334 | list_del_init(&chip->list); |
7299ab70 TR |
335 | |
336 | if (IS_ENABLED(CONFIG_OF)) | |
337 | of_pwmchip_remove(chip); | |
338 | ||
f051c466 | 339 | free_pwms(chip); |
0c2498f1 | 340 | |
76abbdde HS |
341 | pwmchip_sysfs_unexport(chip); |
342 | ||
0c2498f1 SH |
343 | out: |
344 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
345 | return ret; |
346 | } | |
347 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
348 | ||
349 | /** | |
350 | * pwm_request() - request a PWM device | |
04883802 | 351 | * @pwm: global PWM device index |
0c2498f1 | 352 | * @label: PWM device label |
8138d2dd TR |
353 | * |
354 | * This function is deprecated, use pwm_get() instead. | |
04883802 TR |
355 | * |
356 | * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on | |
357 | * failure. | |
0c2498f1 | 358 | */ |
f051c466 | 359 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 360 | { |
f051c466 TR |
361 | struct pwm_device *dev; |
362 | int err; | |
363 | ||
364 | if (pwm < 0 || pwm >= MAX_PWMS) | |
365 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
366 | |
367 | mutex_lock(&pwm_lock); | |
368 | ||
f051c466 TR |
369 | dev = pwm_to_device(pwm); |
370 | if (!dev) { | |
371 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
372 | goto out; |
373 | } | |
374 | ||
f051c466 TR |
375 | err = pwm_device_request(dev, label); |
376 | if (err < 0) | |
377 | dev = ERR_PTR(err); | |
0c2498f1 | 378 | |
f051c466 TR |
379 | out: |
380 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 381 | |
f051c466 TR |
382 | return dev; |
383 | } | |
384 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 385 | |
f051c466 TR |
386 | /** |
387 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
388 | * @chip: PWM chip | |
389 | * @index: per-chip index of the PWM to request | |
390 | * @label: a literal description string of this PWM | |
391 | * | |
04883802 TR |
392 | * Returns: A pointer to the PWM device at the given index of the given PWM |
393 | * chip. A negative error code is returned if the index is not valid for the | |
394 | * specified PWM chip or if the PWM device cannot be requested. | |
f051c466 TR |
395 | */ |
396 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
397 | unsigned int index, | |
398 | const char *label) | |
399 | { | |
400 | struct pwm_device *pwm; | |
401 | int err; | |
0c2498f1 | 402 | |
f051c466 TR |
403 | if (!chip || index >= chip->npwm) |
404 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 405 | |
f051c466 TR |
406 | mutex_lock(&pwm_lock); |
407 | pwm = &chip->pwms[index]; | |
0c2498f1 | 408 | |
f051c466 TR |
409 | err = pwm_device_request(pwm, label); |
410 | if (err < 0) | |
411 | pwm = ERR_PTR(err); | |
412 | ||
413 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
414 | return pwm; |
415 | } | |
f051c466 | 416 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
417 | |
418 | /** | |
419 | * pwm_free() - free a PWM device | |
420 | * @pwm: PWM device | |
8138d2dd TR |
421 | * |
422 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
423 | */ |
424 | void pwm_free(struct pwm_device *pwm) | |
425 | { | |
8138d2dd | 426 | pwm_put(pwm); |
0c2498f1 SH |
427 | } |
428 | EXPORT_SYMBOL_GPL(pwm_free); | |
429 | ||
430 | /** | |
431 | * pwm_config() - change a PWM device configuration | |
432 | * @pwm: PWM device | |
433 | * @duty_ns: "on" time (in nanoseconds) | |
434 | * @period_ns: duration (in nanoseconds) of one cycle | |
04883802 TR |
435 | * |
436 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
437 | */ |
438 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
439 | { | |
76abbdde HS |
440 | int err; |
441 | ||
c2d476a9 | 442 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
443 | return -EINVAL; |
444 | ||
76abbdde HS |
445 | err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
446 | if (err) | |
447 | return err; | |
448 | ||
449 | pwm->duty_cycle = duty_ns; | |
450 | pwm->period = period_ns; | |
451 | ||
452 | return 0; | |
0c2498f1 SH |
453 | } |
454 | EXPORT_SYMBOL_GPL(pwm_config); | |
455 | ||
0aa0869c PA |
456 | /** |
457 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
458 | * @pwm: PWM device | |
459 | * @polarity: new polarity of the PWM signal | |
460 | * | |
04883802 TR |
461 | * Note that the polarity cannot be configured while the PWM device is |
462 | * enabled. | |
463 | * | |
464 | * Returns: 0 on success or a negative error code on failure. | |
0aa0869c PA |
465 | */ |
466 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
467 | { | |
76abbdde HS |
468 | int err; |
469 | ||
0aa0869c PA |
470 | if (!pwm || !pwm->chip->ops) |
471 | return -EINVAL; | |
472 | ||
473 | if (!pwm->chip->ops->set_polarity) | |
474 | return -ENOSYS; | |
475 | ||
5c31252c | 476 | if (pwm_is_enabled(pwm)) |
0aa0869c PA |
477 | return -EBUSY; |
478 | ||
76abbdde HS |
479 | err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); |
480 | if (err) | |
481 | return err; | |
482 | ||
483 | pwm->polarity = polarity; | |
484 | ||
485 | return 0; | |
0aa0869c PA |
486 | } |
487 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
488 | ||
0c2498f1 SH |
489 | /** |
490 | * pwm_enable() - start a PWM output toggling | |
491 | * @pwm: PWM device | |
04883802 TR |
492 | * |
493 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
494 | */ |
495 | int pwm_enable(struct pwm_device *pwm) | |
496 | { | |
f051c466 TR |
497 | if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
498 | return pwm->chip->ops->enable(pwm->chip, pwm); | |
0c2498f1 | 499 | |
f051c466 | 500 | return pwm ? 0 : -EINVAL; |
0c2498f1 SH |
501 | } |
502 | EXPORT_SYMBOL_GPL(pwm_enable); | |
503 | ||
504 | /** | |
505 | * pwm_disable() - stop a PWM output toggling | |
506 | * @pwm: PWM device | |
507 | */ | |
508 | void pwm_disable(struct pwm_device *pwm) | |
509 | { | |
f051c466 TR |
510 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
511 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
512 | } |
513 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 514 | |
7299ab70 TR |
515 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
516 | { | |
517 | struct pwm_chip *chip; | |
518 | ||
519 | mutex_lock(&pwm_lock); | |
520 | ||
521 | list_for_each_entry(chip, &pwm_chips, list) | |
522 | if (chip->dev && chip->dev->of_node == np) { | |
523 | mutex_unlock(&pwm_lock); | |
524 | return chip; | |
525 | } | |
526 | ||
527 | mutex_unlock(&pwm_lock); | |
528 | ||
529 | return ERR_PTR(-EPROBE_DEFER); | |
530 | } | |
531 | ||
532 | /** | |
8eb96127 | 533 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
534 | * @np: device node to get the PWM from |
535 | * @con_id: consumer name | |
536 | * | |
537 | * Returns the PWM device parsed from the phandle and index specified in the | |
538 | * "pwms" property of a device tree node or a negative error-code on failure. | |
539 | * Values parsed from the device tree are stored in the returned PWM device | |
540 | * object. | |
541 | * | |
542 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
543 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
544 | * lookup of the PWM index. This also means that the "pwm-names" property | |
545 | * becomes mandatory for devices that look up the PWM device via the con_id | |
546 | * parameter. | |
04883802 TR |
547 | * |
548 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
549 | * error code on failure. | |
7299ab70 | 550 | */ |
8eb96127 | 551 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
552 | { |
553 | struct pwm_device *pwm = NULL; | |
554 | struct of_phandle_args args; | |
555 | struct pwm_chip *pc; | |
556 | int index = 0; | |
557 | int err; | |
558 | ||
559 | if (con_id) { | |
560 | index = of_property_match_string(np, "pwm-names", con_id); | |
561 | if (index < 0) | |
562 | return ERR_PTR(index); | |
563 | } | |
564 | ||
565 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
566 | &args); | |
567 | if (err) { | |
568 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
569 | return ERR_PTR(err); | |
570 | } | |
571 | ||
572 | pc = of_node_to_pwmchip(args.np); | |
573 | if (IS_ERR(pc)) { | |
574 | pr_debug("%s(): PWM chip not found\n", __func__); | |
575 | pwm = ERR_CAST(pc); | |
576 | goto put; | |
577 | } | |
578 | ||
579 | if (args.args_count != pc->of_pwm_n_cells) { | |
580 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
581 | args.np->full_name); | |
582 | pwm = ERR_PTR(-EINVAL); | |
583 | goto put; | |
584 | } | |
585 | ||
586 | pwm = pc->of_xlate(pc, &args); | |
587 | if (IS_ERR(pwm)) | |
588 | goto put; | |
589 | ||
590 | /* | |
591 | * If a consumer name was not given, try to look it up from the | |
592 | * "pwm-names" property if it exists. Otherwise use the name of | |
593 | * the user device node. | |
594 | */ | |
595 | if (!con_id) { | |
596 | err = of_property_read_string_index(np, "pwm-names", index, | |
597 | &con_id); | |
598 | if (err < 0) | |
599 | con_id = np->name; | |
600 | } | |
601 | ||
602 | pwm->label = con_id; | |
603 | ||
604 | put: | |
605 | of_node_put(args.np); | |
606 | ||
607 | return pwm; | |
608 | } | |
8eb96127 | 609 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 610 | |
8138d2dd TR |
611 | /** |
612 | * pwm_add_table() - register PWM device consumers | |
613 | * @table: array of consumers to register | |
614 | * @num: number of consumers in table | |
615 | */ | |
c264f111 | 616 | void pwm_add_table(struct pwm_lookup *table, size_t num) |
8138d2dd TR |
617 | { |
618 | mutex_lock(&pwm_lookup_lock); | |
619 | ||
620 | while (num--) { | |
621 | list_add_tail(&table->list, &pwm_lookup_list); | |
622 | table++; | |
623 | } | |
624 | ||
625 | mutex_unlock(&pwm_lookup_lock); | |
626 | } | |
627 | ||
efb0de55 SK |
628 | /** |
629 | * pwm_remove_table() - unregister PWM device consumers | |
630 | * @table: array of consumers to unregister | |
631 | * @num: number of consumers in table | |
632 | */ | |
633 | void pwm_remove_table(struct pwm_lookup *table, size_t num) | |
634 | { | |
635 | mutex_lock(&pwm_lookup_lock); | |
636 | ||
637 | while (num--) { | |
638 | list_del(&table->list); | |
639 | table++; | |
640 | } | |
641 | ||
642 | mutex_unlock(&pwm_lookup_lock); | |
643 | } | |
644 | ||
8138d2dd TR |
645 | /** |
646 | * pwm_get() - look up and request a PWM device | |
647 | * @dev: device for PWM consumer | |
648 | * @con_id: consumer name | |
649 | * | |
7299ab70 TR |
650 | * Lookup is first attempted using DT. If the device was not instantiated from |
651 | * a device tree, a PWM chip and a relative index is looked up via a table | |
652 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
653 | * |
654 | * Once a PWM chip has been found the specified PWM device will be requested | |
655 | * and is ready to be used. | |
04883802 TR |
656 | * |
657 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
658 | * error code on failure. | |
8138d2dd TR |
659 | */ |
660 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
661 | { | |
662 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 663 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd TR |
664 | struct pwm_chip *chip = NULL; |
665 | unsigned int best = 0; | |
70145f87 | 666 | struct pwm_lookup *p, *chosen = NULL; |
8138d2dd TR |
667 | unsigned int match; |
668 | ||
7299ab70 TR |
669 | /* look up via DT first */ |
670 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 671 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 672 | |
8138d2dd TR |
673 | /* |
674 | * We look up the provider in the static table typically provided by | |
675 | * board setup code. We first try to lookup the consumer device by | |
676 | * name. If the consumer device was passed in as NULL or if no match | |
677 | * was found, we try to find the consumer by directly looking it up | |
678 | * by name. | |
679 | * | |
680 | * If a match is found, the provider PWM chip is looked up by name | |
681 | * and a PWM device is requested using the PWM device per-chip index. | |
682 | * | |
683 | * The lookup algorithm was shamelessly taken from the clock | |
684 | * framework: | |
685 | * | |
686 | * We do slightly fuzzy matching here: | |
687 | * An entry with a NULL ID is assumed to be a wildcard. | |
688 | * If an entry has a device ID, it must match | |
689 | * If an entry has a connection ID, it must match | |
690 | * Then we take the most specific entry - with the following order | |
691 | * of precedence: dev+con > dev only > con only. | |
692 | */ | |
693 | mutex_lock(&pwm_lookup_lock); | |
694 | ||
695 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
696 | match = 0; | |
697 | ||
698 | if (p->dev_id) { | |
699 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
700 | continue; | |
701 | ||
702 | match += 2; | |
703 | } | |
704 | ||
705 | if (p->con_id) { | |
706 | if (!con_id || strcmp(p->con_id, con_id)) | |
707 | continue; | |
708 | ||
709 | match += 1; | |
710 | } | |
711 | ||
712 | if (match > best) { | |
70145f87 | 713 | chosen = p; |
8138d2dd TR |
714 | |
715 | if (match != 3) | |
716 | best = match; | |
717 | else | |
718 | break; | |
719 | } | |
720 | } | |
721 | ||
70145f87 GU |
722 | if (!chosen) |
723 | goto out; | |
3796ce1d | 724 | |
70145f87 GU |
725 | chip = pwmchip_find_by_name(chosen->provider); |
726 | if (!chip) | |
727 | goto out; | |
3796ce1d | 728 | |
70145f87 GU |
729 | pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
730 | if (IS_ERR(pwm)) | |
731 | goto out; | |
8138d2dd | 732 | |
70145f87 GU |
733 | pwm_set_period(pwm, chosen->period); |
734 | pwm_set_polarity(pwm, chosen->polarity); | |
8138d2dd | 735 | |
70145f87 GU |
736 | out: |
737 | mutex_unlock(&pwm_lookup_lock); | |
8138d2dd TR |
738 | return pwm; |
739 | } | |
740 | EXPORT_SYMBOL_GPL(pwm_get); | |
741 | ||
742 | /** | |
743 | * pwm_put() - release a PWM device | |
744 | * @pwm: PWM device | |
745 | */ | |
746 | void pwm_put(struct pwm_device *pwm) | |
747 | { | |
748 | if (!pwm) | |
749 | return; | |
750 | ||
751 | mutex_lock(&pwm_lock); | |
752 | ||
753 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 754 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
755 | goto out; |
756 | } | |
757 | ||
758 | if (pwm->chip->ops->free) | |
759 | pwm->chip->ops->free(pwm->chip, pwm); | |
760 | ||
761 | pwm->label = NULL; | |
762 | ||
763 | module_put(pwm->chip->ops->owner); | |
764 | out: | |
765 | mutex_unlock(&pwm_lock); | |
766 | } | |
767 | EXPORT_SYMBOL_GPL(pwm_put); | |
768 | ||
6354316d AC |
769 | static void devm_pwm_release(struct device *dev, void *res) |
770 | { | |
771 | pwm_put(*(struct pwm_device **)res); | |
772 | } | |
773 | ||
774 | /** | |
775 | * devm_pwm_get() - resource managed pwm_get() | |
776 | * @dev: device for PWM consumer | |
777 | * @con_id: consumer name | |
778 | * | |
779 | * This function performs like pwm_get() but the acquired PWM device will | |
780 | * automatically be released on driver detach. | |
04883802 TR |
781 | * |
782 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
783 | * error code on failure. | |
6354316d AC |
784 | */ |
785 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
786 | { | |
787 | struct pwm_device **ptr, *pwm; | |
788 | ||
77f0b9d2 | 789 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
6354316d AC |
790 | if (!ptr) |
791 | return ERR_PTR(-ENOMEM); | |
792 | ||
793 | pwm = pwm_get(dev, con_id); | |
794 | if (!IS_ERR(pwm)) { | |
795 | *ptr = pwm; | |
796 | devres_add(dev, ptr); | |
797 | } else { | |
798 | devres_free(ptr); | |
799 | } | |
800 | ||
801 | return pwm; | |
802 | } | |
803 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
804 | ||
261a5edd PU |
805 | /** |
806 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
807 | * @dev: device for PWM consumer | |
808 | * @np: device node to get the PWM from | |
809 | * @con_id: consumer name | |
810 | * | |
811 | * This function performs like of_pwm_get() but the acquired PWM device will | |
812 | * automatically be released on driver detach. | |
04883802 TR |
813 | * |
814 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
815 | * error code on failure. | |
261a5edd PU |
816 | */ |
817 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
818 | const char *con_id) | |
819 | { | |
820 | struct pwm_device **ptr, *pwm; | |
821 | ||
77f0b9d2 | 822 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
261a5edd PU |
823 | if (!ptr) |
824 | return ERR_PTR(-ENOMEM); | |
825 | ||
826 | pwm = of_pwm_get(np, con_id); | |
827 | if (!IS_ERR(pwm)) { | |
828 | *ptr = pwm; | |
829 | devres_add(dev, ptr); | |
830 | } else { | |
831 | devres_free(ptr); | |
832 | } | |
833 | ||
834 | return pwm; | |
835 | } | |
836 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
837 | ||
6354316d AC |
838 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
839 | { | |
840 | struct pwm_device **p = res; | |
841 | ||
842 | if (WARN_ON(!p || !*p)) | |
843 | return 0; | |
844 | ||
845 | return *p == data; | |
846 | } | |
847 | ||
848 | /** | |
849 | * devm_pwm_put() - resource managed pwm_put() | |
850 | * @dev: device for PWM consumer | |
851 | * @pwm: PWM device | |
852 | * | |
853 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
854 | * function is usually not needed because devm-allocated resources are | |
855 | * automatically released on driver detach. | |
856 | */ | |
857 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
858 | { | |
859 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
860 | } | |
861 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
862 | ||
6e69ab13 FV |
863 | /** |
864 | * pwm_can_sleep() - report whether PWM access will sleep | |
865 | * @pwm: PWM device | |
866 | * | |
04883802 | 867 | * Returns: True if accessing the PWM can sleep, false otherwise. |
6e69ab13 FV |
868 | */ |
869 | bool pwm_can_sleep(struct pwm_device *pwm) | |
870 | { | |
871 | return pwm->chip->can_sleep; | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
874 | ||
62099abf TR |
875 | #ifdef CONFIG_DEBUG_FS |
876 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
877 | { | |
878 | unsigned int i; | |
879 | ||
880 | for (i = 0; i < chip->npwm; i++) { | |
881 | struct pwm_device *pwm = &chip->pwms[i]; | |
882 | ||
883 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
884 | ||
885 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
adcba1e3 | 886 | seq_puts(s, " requested"); |
62099abf | 887 | |
5c31252c | 888 | if (pwm_is_enabled(pwm)) |
adcba1e3 | 889 | seq_puts(s, " enabled"); |
62099abf | 890 | |
adcba1e3 | 891 | seq_puts(s, "\n"); |
62099abf TR |
892 | } |
893 | } | |
894 | ||
895 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
896 | { | |
897 | mutex_lock(&pwm_lock); | |
898 | s->private = ""; | |
899 | ||
900 | return seq_list_start(&pwm_chips, *pos); | |
901 | } | |
902 | ||
903 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
904 | { | |
905 | s->private = "\n"; | |
906 | ||
907 | return seq_list_next(v, &pwm_chips, pos); | |
908 | } | |
909 | ||
910 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
911 | { | |
912 | mutex_unlock(&pwm_lock); | |
913 | } | |
914 | ||
915 | static int pwm_seq_show(struct seq_file *s, void *v) | |
916 | { | |
917 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
918 | ||
919 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
920 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
921 | dev_name(chip->dev), chip->npwm, | |
922 | (chip->npwm != 1) ? "s" : ""); | |
923 | ||
924 | if (chip->ops->dbg_show) | |
925 | chip->ops->dbg_show(chip, s); | |
926 | else | |
927 | pwm_dbg_show(chip, s); | |
928 | ||
929 | return 0; | |
930 | } | |
931 | ||
932 | static const struct seq_operations pwm_seq_ops = { | |
933 | .start = pwm_seq_start, | |
934 | .next = pwm_seq_next, | |
935 | .stop = pwm_seq_stop, | |
936 | .show = pwm_seq_show, | |
937 | }; | |
938 | ||
939 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
940 | { | |
941 | return seq_open(file, &pwm_seq_ops); | |
942 | } | |
943 | ||
944 | static const struct file_operations pwm_debugfs_ops = { | |
945 | .owner = THIS_MODULE, | |
946 | .open = pwm_seq_open, | |
947 | .read = seq_read, | |
948 | .llseek = seq_lseek, | |
949 | .release = seq_release, | |
950 | }; | |
951 | ||
952 | static int __init pwm_debugfs_init(void) | |
953 | { | |
954 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
955 | &pwm_debugfs_ops); | |
956 | ||
957 | return 0; | |
958 | } | |
62099abf TR |
959 | subsys_initcall(pwm_debugfs_init); |
960 | #endif /* CONFIG_DEBUG_FS */ |