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; |
d1cd2142 | 272 | mutex_init(&pwm->lock); |
0c2498f1 | 273 | |
f051c466 TR |
274 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
275 | } | |
276 | ||
277 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
278 | ||
279 | INIT_LIST_HEAD(&chip->list); | |
280 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 281 | |
f051c466 TR |
282 | ret = 0; |
283 | ||
7299ab70 TR |
284 | if (IS_ENABLED(CONFIG_OF)) |
285 | of_pwmchip_add(chip); | |
286 | ||
76abbdde HS |
287 | pwmchip_sysfs_export(chip); |
288 | ||
f051c466 TR |
289 | out: |
290 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
291 | return ret; |
292 | } | |
b6a00fae TK |
293 | EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); |
294 | ||
295 | /** | |
296 | * pwmchip_add() - register a new PWM chip | |
297 | * @chip: the PWM chip to add | |
298 | * | |
299 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
300 | * will be used. The initial polarity for all channels is normal. | |
04883802 TR |
301 | * |
302 | * Returns: 0 on success or a negative error code on failure. | |
b6a00fae TK |
303 | */ |
304 | int pwmchip_add(struct pwm_chip *chip) | |
305 | { | |
306 | return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); | |
307 | } | |
0c2498f1 SH |
308 | EXPORT_SYMBOL_GPL(pwmchip_add); |
309 | ||
310 | /** | |
311 | * pwmchip_remove() - remove a PWM chip | |
312 | * @chip: the PWM chip to remove | |
313 | * | |
314 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
315 | * a PWM device that is still requested. | |
04883802 TR |
316 | * |
317 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
318 | */ |
319 | int pwmchip_remove(struct pwm_chip *chip) | |
320 | { | |
f051c466 | 321 | unsigned int i; |
0c2498f1 SH |
322 | int ret = 0; |
323 | ||
324 | mutex_lock(&pwm_lock); | |
325 | ||
f051c466 TR |
326 | for (i = 0; i < chip->npwm; i++) { |
327 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 328 | |
f051c466 TR |
329 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
330 | ret = -EBUSY; | |
331 | goto out; | |
332 | } | |
0c2498f1 SH |
333 | } |
334 | ||
f051c466 | 335 | list_del_init(&chip->list); |
7299ab70 TR |
336 | |
337 | if (IS_ENABLED(CONFIG_OF)) | |
338 | of_pwmchip_remove(chip); | |
339 | ||
f051c466 | 340 | free_pwms(chip); |
0c2498f1 | 341 | |
76abbdde HS |
342 | pwmchip_sysfs_unexport(chip); |
343 | ||
0c2498f1 SH |
344 | out: |
345 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
346 | return ret; |
347 | } | |
348 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
349 | ||
350 | /** | |
351 | * pwm_request() - request a PWM device | |
04883802 | 352 | * @pwm: global PWM device index |
0c2498f1 | 353 | * @label: PWM device label |
8138d2dd TR |
354 | * |
355 | * This function is deprecated, use pwm_get() instead. | |
04883802 TR |
356 | * |
357 | * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on | |
358 | * failure. | |
0c2498f1 | 359 | */ |
f051c466 | 360 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 361 | { |
f051c466 TR |
362 | struct pwm_device *dev; |
363 | int err; | |
364 | ||
365 | if (pwm < 0 || pwm >= MAX_PWMS) | |
366 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
367 | |
368 | mutex_lock(&pwm_lock); | |
369 | ||
f051c466 TR |
370 | dev = pwm_to_device(pwm); |
371 | if (!dev) { | |
372 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
373 | goto out; |
374 | } | |
375 | ||
f051c466 TR |
376 | err = pwm_device_request(dev, label); |
377 | if (err < 0) | |
378 | dev = ERR_PTR(err); | |
0c2498f1 | 379 | |
f051c466 TR |
380 | out: |
381 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 382 | |
f051c466 TR |
383 | return dev; |
384 | } | |
385 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 386 | |
f051c466 TR |
387 | /** |
388 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
389 | * @chip: PWM chip | |
390 | * @index: per-chip index of the PWM to request | |
391 | * @label: a literal description string of this PWM | |
392 | * | |
04883802 TR |
393 | * Returns: A pointer to the PWM device at the given index of the given PWM |
394 | * chip. A negative error code is returned if the index is not valid for the | |
395 | * specified PWM chip or if the PWM device cannot be requested. | |
f051c466 TR |
396 | */ |
397 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
398 | unsigned int index, | |
399 | const char *label) | |
400 | { | |
401 | struct pwm_device *pwm; | |
402 | int err; | |
0c2498f1 | 403 | |
f051c466 TR |
404 | if (!chip || index >= chip->npwm) |
405 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 406 | |
f051c466 TR |
407 | mutex_lock(&pwm_lock); |
408 | pwm = &chip->pwms[index]; | |
0c2498f1 | 409 | |
f051c466 TR |
410 | err = pwm_device_request(pwm, label); |
411 | if (err < 0) | |
412 | pwm = ERR_PTR(err); | |
413 | ||
414 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
415 | return pwm; |
416 | } | |
f051c466 | 417 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
418 | |
419 | /** | |
420 | * pwm_free() - free a PWM device | |
421 | * @pwm: PWM device | |
8138d2dd TR |
422 | * |
423 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
424 | */ |
425 | void pwm_free(struct pwm_device *pwm) | |
426 | { | |
8138d2dd | 427 | pwm_put(pwm); |
0c2498f1 SH |
428 | } |
429 | EXPORT_SYMBOL_GPL(pwm_free); | |
430 | ||
431 | /** | |
432 | * pwm_config() - change a PWM device configuration | |
433 | * @pwm: PWM device | |
434 | * @duty_ns: "on" time (in nanoseconds) | |
435 | * @period_ns: duration (in nanoseconds) of one cycle | |
04883802 TR |
436 | * |
437 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
438 | */ |
439 | int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) | |
440 | { | |
76abbdde HS |
441 | int err; |
442 | ||
c2d476a9 | 443 | if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
f051c466 TR |
444 | return -EINVAL; |
445 | ||
76abbdde HS |
446 | err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
447 | if (err) | |
448 | return err; | |
449 | ||
450 | pwm->duty_cycle = duty_ns; | |
451 | pwm->period = period_ns; | |
452 | ||
453 | return 0; | |
0c2498f1 SH |
454 | } |
455 | EXPORT_SYMBOL_GPL(pwm_config); | |
456 | ||
0aa0869c PA |
457 | /** |
458 | * pwm_set_polarity() - configure the polarity of a PWM signal | |
459 | * @pwm: PWM device | |
460 | * @polarity: new polarity of the PWM signal | |
461 | * | |
04883802 TR |
462 | * Note that the polarity cannot be configured while the PWM device is |
463 | * enabled. | |
464 | * | |
465 | * Returns: 0 on success or a negative error code on failure. | |
0aa0869c PA |
466 | */ |
467 | int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) | |
468 | { | |
76abbdde HS |
469 | int err; |
470 | ||
0aa0869c PA |
471 | if (!pwm || !pwm->chip->ops) |
472 | return -EINVAL; | |
473 | ||
474 | if (!pwm->chip->ops->set_polarity) | |
475 | return -ENOSYS; | |
476 | ||
d1cd2142 JR |
477 | mutex_lock(&pwm->lock); |
478 | ||
479 | if (pwm_is_enabled(pwm)) { | |
480 | err = -EBUSY; | |
481 | goto unlock; | |
482 | } | |
0aa0869c | 483 | |
76abbdde HS |
484 | err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); |
485 | if (err) | |
d1cd2142 | 486 | goto unlock; |
76abbdde HS |
487 | |
488 | pwm->polarity = polarity; | |
489 | ||
d1cd2142 JR |
490 | unlock: |
491 | mutex_unlock(&pwm->lock); | |
492 | return err; | |
0aa0869c PA |
493 | } |
494 | EXPORT_SYMBOL_GPL(pwm_set_polarity); | |
495 | ||
0c2498f1 SH |
496 | /** |
497 | * pwm_enable() - start a PWM output toggling | |
498 | * @pwm: PWM device | |
04883802 TR |
499 | * |
500 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
501 | */ |
502 | int pwm_enable(struct pwm_device *pwm) | |
503 | { | |
d1cd2142 JR |
504 | int err = 0; |
505 | ||
506 | if (!pwm) | |
507 | return -EINVAL; | |
508 | ||
509 | mutex_lock(&pwm->lock); | |
510 | ||
511 | if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) { | |
512 | err = pwm->chip->ops->enable(pwm->chip, pwm); | |
513 | if (err) | |
514 | clear_bit(PWMF_ENABLED, &pwm->flags); | |
515 | } | |
516 | ||
517 | mutex_unlock(&pwm->lock); | |
0c2498f1 | 518 | |
d1cd2142 | 519 | return err; |
0c2498f1 SH |
520 | } |
521 | EXPORT_SYMBOL_GPL(pwm_enable); | |
522 | ||
523 | /** | |
524 | * pwm_disable() - stop a PWM output toggling | |
525 | * @pwm: PWM device | |
526 | */ | |
527 | void pwm_disable(struct pwm_device *pwm) | |
528 | { | |
f051c466 TR |
529 | if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
530 | pwm->chip->ops->disable(pwm->chip, pwm); | |
0c2498f1 SH |
531 | } |
532 | EXPORT_SYMBOL_GPL(pwm_disable); | |
62099abf | 533 | |
7299ab70 TR |
534 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
535 | { | |
536 | struct pwm_chip *chip; | |
537 | ||
538 | mutex_lock(&pwm_lock); | |
539 | ||
540 | list_for_each_entry(chip, &pwm_chips, list) | |
541 | if (chip->dev && chip->dev->of_node == np) { | |
542 | mutex_unlock(&pwm_lock); | |
543 | return chip; | |
544 | } | |
545 | ||
546 | mutex_unlock(&pwm_lock); | |
547 | ||
548 | return ERR_PTR(-EPROBE_DEFER); | |
549 | } | |
550 | ||
551 | /** | |
8eb96127 | 552 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
553 | * @np: device node to get the PWM from |
554 | * @con_id: consumer name | |
555 | * | |
556 | * Returns the PWM device parsed from the phandle and index specified in the | |
557 | * "pwms" property of a device tree node or a negative error-code on failure. | |
558 | * Values parsed from the device tree are stored in the returned PWM device | |
559 | * object. | |
560 | * | |
561 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
562 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
563 | * lookup of the PWM index. This also means that the "pwm-names" property | |
564 | * becomes mandatory for devices that look up the PWM device via the con_id | |
565 | * parameter. | |
04883802 TR |
566 | * |
567 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
568 | * error code on failure. | |
7299ab70 | 569 | */ |
8eb96127 | 570 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
571 | { |
572 | struct pwm_device *pwm = NULL; | |
573 | struct of_phandle_args args; | |
574 | struct pwm_chip *pc; | |
575 | int index = 0; | |
576 | int err; | |
577 | ||
578 | if (con_id) { | |
579 | index = of_property_match_string(np, "pwm-names", con_id); | |
580 | if (index < 0) | |
581 | return ERR_PTR(index); | |
582 | } | |
583 | ||
584 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
585 | &args); | |
586 | if (err) { | |
587 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
588 | return ERR_PTR(err); | |
589 | } | |
590 | ||
591 | pc = of_node_to_pwmchip(args.np); | |
592 | if (IS_ERR(pc)) { | |
593 | pr_debug("%s(): PWM chip not found\n", __func__); | |
594 | pwm = ERR_CAST(pc); | |
595 | goto put; | |
596 | } | |
597 | ||
598 | if (args.args_count != pc->of_pwm_n_cells) { | |
599 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
600 | args.np->full_name); | |
601 | pwm = ERR_PTR(-EINVAL); | |
602 | goto put; | |
603 | } | |
604 | ||
605 | pwm = pc->of_xlate(pc, &args); | |
606 | if (IS_ERR(pwm)) | |
607 | goto put; | |
608 | ||
609 | /* | |
610 | * If a consumer name was not given, try to look it up from the | |
611 | * "pwm-names" property if it exists. Otherwise use the name of | |
612 | * the user device node. | |
613 | */ | |
614 | if (!con_id) { | |
615 | err = of_property_read_string_index(np, "pwm-names", index, | |
616 | &con_id); | |
617 | if (err < 0) | |
618 | con_id = np->name; | |
619 | } | |
620 | ||
621 | pwm->label = con_id; | |
622 | ||
623 | put: | |
624 | of_node_put(args.np); | |
625 | ||
626 | return pwm; | |
627 | } | |
8eb96127 | 628 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 629 | |
8138d2dd TR |
630 | /** |
631 | * pwm_add_table() - register PWM device consumers | |
632 | * @table: array of consumers to register | |
633 | * @num: number of consumers in table | |
634 | */ | |
c264f111 | 635 | void pwm_add_table(struct pwm_lookup *table, size_t num) |
8138d2dd TR |
636 | { |
637 | mutex_lock(&pwm_lookup_lock); | |
638 | ||
639 | while (num--) { | |
640 | list_add_tail(&table->list, &pwm_lookup_list); | |
641 | table++; | |
642 | } | |
643 | ||
644 | mutex_unlock(&pwm_lookup_lock); | |
645 | } | |
646 | ||
efb0de55 SK |
647 | /** |
648 | * pwm_remove_table() - unregister PWM device consumers | |
649 | * @table: array of consumers to unregister | |
650 | * @num: number of consumers in table | |
651 | */ | |
652 | void pwm_remove_table(struct pwm_lookup *table, size_t num) | |
653 | { | |
654 | mutex_lock(&pwm_lookup_lock); | |
655 | ||
656 | while (num--) { | |
657 | list_del(&table->list); | |
658 | table++; | |
659 | } | |
660 | ||
661 | mutex_unlock(&pwm_lookup_lock); | |
662 | } | |
663 | ||
8138d2dd TR |
664 | /** |
665 | * pwm_get() - look up and request a PWM device | |
666 | * @dev: device for PWM consumer | |
667 | * @con_id: consumer name | |
668 | * | |
7299ab70 TR |
669 | * Lookup is first attempted using DT. If the device was not instantiated from |
670 | * a device tree, a PWM chip and a relative index is looked up via a table | |
671 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
672 | * |
673 | * Once a PWM chip has been found the specified PWM device will be requested | |
674 | * and is ready to be used. | |
04883802 TR |
675 | * |
676 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
677 | * error code on failure. | |
8138d2dd TR |
678 | */ |
679 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
680 | { | |
681 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 682 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd TR |
683 | struct pwm_chip *chip = NULL; |
684 | unsigned int best = 0; | |
70145f87 | 685 | struct pwm_lookup *p, *chosen = NULL; |
8138d2dd TR |
686 | unsigned int match; |
687 | ||
7299ab70 TR |
688 | /* look up via DT first */ |
689 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 690 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 691 | |
8138d2dd TR |
692 | /* |
693 | * We look up the provider in the static table typically provided by | |
694 | * board setup code. We first try to lookup the consumer device by | |
695 | * name. If the consumer device was passed in as NULL or if no match | |
696 | * was found, we try to find the consumer by directly looking it up | |
697 | * by name. | |
698 | * | |
699 | * If a match is found, the provider PWM chip is looked up by name | |
700 | * and a PWM device is requested using the PWM device per-chip index. | |
701 | * | |
702 | * The lookup algorithm was shamelessly taken from the clock | |
703 | * framework: | |
704 | * | |
705 | * We do slightly fuzzy matching here: | |
706 | * An entry with a NULL ID is assumed to be a wildcard. | |
707 | * If an entry has a device ID, it must match | |
708 | * If an entry has a connection ID, it must match | |
709 | * Then we take the most specific entry - with the following order | |
710 | * of precedence: dev+con > dev only > con only. | |
711 | */ | |
712 | mutex_lock(&pwm_lookup_lock); | |
713 | ||
714 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
715 | match = 0; | |
716 | ||
717 | if (p->dev_id) { | |
718 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
719 | continue; | |
720 | ||
721 | match += 2; | |
722 | } | |
723 | ||
724 | if (p->con_id) { | |
725 | if (!con_id || strcmp(p->con_id, con_id)) | |
726 | continue; | |
727 | ||
728 | match += 1; | |
729 | } | |
730 | ||
731 | if (match > best) { | |
70145f87 | 732 | chosen = p; |
8138d2dd TR |
733 | |
734 | if (match != 3) | |
735 | best = match; | |
736 | else | |
737 | break; | |
738 | } | |
739 | } | |
740 | ||
70145f87 GU |
741 | if (!chosen) |
742 | goto out; | |
3796ce1d | 743 | |
70145f87 GU |
744 | chip = pwmchip_find_by_name(chosen->provider); |
745 | if (!chip) | |
746 | goto out; | |
3796ce1d | 747 | |
70145f87 GU |
748 | pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
749 | if (IS_ERR(pwm)) | |
750 | goto out; | |
8138d2dd | 751 | |
70145f87 GU |
752 | pwm_set_period(pwm, chosen->period); |
753 | pwm_set_polarity(pwm, chosen->polarity); | |
8138d2dd | 754 | |
70145f87 GU |
755 | out: |
756 | mutex_unlock(&pwm_lookup_lock); | |
8138d2dd TR |
757 | return pwm; |
758 | } | |
759 | EXPORT_SYMBOL_GPL(pwm_get); | |
760 | ||
761 | /** | |
762 | * pwm_put() - release a PWM device | |
763 | * @pwm: PWM device | |
764 | */ | |
765 | void pwm_put(struct pwm_device *pwm) | |
766 | { | |
767 | if (!pwm) | |
768 | return; | |
769 | ||
770 | mutex_lock(&pwm_lock); | |
771 | ||
772 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 773 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
774 | goto out; |
775 | } | |
776 | ||
777 | if (pwm->chip->ops->free) | |
778 | pwm->chip->ops->free(pwm->chip, pwm); | |
779 | ||
780 | pwm->label = NULL; | |
781 | ||
782 | module_put(pwm->chip->ops->owner); | |
783 | out: | |
784 | mutex_unlock(&pwm_lock); | |
785 | } | |
786 | EXPORT_SYMBOL_GPL(pwm_put); | |
787 | ||
6354316d AC |
788 | static void devm_pwm_release(struct device *dev, void *res) |
789 | { | |
790 | pwm_put(*(struct pwm_device **)res); | |
791 | } | |
792 | ||
793 | /** | |
794 | * devm_pwm_get() - resource managed pwm_get() | |
795 | * @dev: device for PWM consumer | |
796 | * @con_id: consumer name | |
797 | * | |
798 | * This function performs like pwm_get() but the acquired PWM device will | |
799 | * automatically be released on driver detach. | |
04883802 TR |
800 | * |
801 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
802 | * error code on failure. | |
6354316d AC |
803 | */ |
804 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
805 | { | |
806 | struct pwm_device **ptr, *pwm; | |
807 | ||
77f0b9d2 | 808 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
6354316d AC |
809 | if (!ptr) |
810 | return ERR_PTR(-ENOMEM); | |
811 | ||
812 | pwm = pwm_get(dev, con_id); | |
813 | if (!IS_ERR(pwm)) { | |
814 | *ptr = pwm; | |
815 | devres_add(dev, ptr); | |
816 | } else { | |
817 | devres_free(ptr); | |
818 | } | |
819 | ||
820 | return pwm; | |
821 | } | |
822 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
823 | ||
261a5edd PU |
824 | /** |
825 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
826 | * @dev: device for PWM consumer | |
827 | * @np: device node to get the PWM from | |
828 | * @con_id: consumer name | |
829 | * | |
830 | * This function performs like of_pwm_get() but the acquired PWM device will | |
831 | * automatically be released on driver detach. | |
04883802 TR |
832 | * |
833 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
834 | * error code on failure. | |
261a5edd PU |
835 | */ |
836 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
837 | const char *con_id) | |
838 | { | |
839 | struct pwm_device **ptr, *pwm; | |
840 | ||
77f0b9d2 | 841 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
261a5edd PU |
842 | if (!ptr) |
843 | return ERR_PTR(-ENOMEM); | |
844 | ||
845 | pwm = of_pwm_get(np, con_id); | |
846 | if (!IS_ERR(pwm)) { | |
847 | *ptr = pwm; | |
848 | devres_add(dev, ptr); | |
849 | } else { | |
850 | devres_free(ptr); | |
851 | } | |
852 | ||
853 | return pwm; | |
854 | } | |
855 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
856 | ||
6354316d AC |
857 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
858 | { | |
859 | struct pwm_device **p = res; | |
860 | ||
861 | if (WARN_ON(!p || !*p)) | |
862 | return 0; | |
863 | ||
864 | return *p == data; | |
865 | } | |
866 | ||
867 | /** | |
868 | * devm_pwm_put() - resource managed pwm_put() | |
869 | * @dev: device for PWM consumer | |
870 | * @pwm: PWM device | |
871 | * | |
872 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
873 | * function is usually not needed because devm-allocated resources are | |
874 | * automatically released on driver detach. | |
875 | */ | |
876 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
877 | { | |
878 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
879 | } | |
880 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
881 | ||
6e69ab13 FV |
882 | /** |
883 | * pwm_can_sleep() - report whether PWM access will sleep | |
884 | * @pwm: PWM device | |
885 | * | |
04883802 | 886 | * Returns: True if accessing the PWM can sleep, false otherwise. |
6e69ab13 FV |
887 | */ |
888 | bool pwm_can_sleep(struct pwm_device *pwm) | |
889 | { | |
890 | return pwm->chip->can_sleep; | |
891 | } | |
892 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
893 | ||
62099abf TR |
894 | #ifdef CONFIG_DEBUG_FS |
895 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
896 | { | |
897 | unsigned int i; | |
898 | ||
899 | for (i = 0; i < chip->npwm; i++) { | |
900 | struct pwm_device *pwm = &chip->pwms[i]; | |
901 | ||
902 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
903 | ||
904 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
adcba1e3 | 905 | seq_puts(s, " requested"); |
62099abf | 906 | |
5c31252c | 907 | if (pwm_is_enabled(pwm)) |
adcba1e3 | 908 | seq_puts(s, " enabled"); |
62099abf | 909 | |
adcba1e3 | 910 | seq_puts(s, "\n"); |
62099abf TR |
911 | } |
912 | } | |
913 | ||
914 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
915 | { | |
916 | mutex_lock(&pwm_lock); | |
917 | s->private = ""; | |
918 | ||
919 | return seq_list_start(&pwm_chips, *pos); | |
920 | } | |
921 | ||
922 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
923 | { | |
924 | s->private = "\n"; | |
925 | ||
926 | return seq_list_next(v, &pwm_chips, pos); | |
927 | } | |
928 | ||
929 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
930 | { | |
931 | mutex_unlock(&pwm_lock); | |
932 | } | |
933 | ||
934 | static int pwm_seq_show(struct seq_file *s, void *v) | |
935 | { | |
936 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
937 | ||
938 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
939 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
940 | dev_name(chip->dev), chip->npwm, | |
941 | (chip->npwm != 1) ? "s" : ""); | |
942 | ||
943 | if (chip->ops->dbg_show) | |
944 | chip->ops->dbg_show(chip, s); | |
945 | else | |
946 | pwm_dbg_show(chip, s); | |
947 | ||
948 | return 0; | |
949 | } | |
950 | ||
951 | static const struct seq_operations pwm_seq_ops = { | |
952 | .start = pwm_seq_start, | |
953 | .next = pwm_seq_next, | |
954 | .stop = pwm_seq_stop, | |
955 | .show = pwm_seq_show, | |
956 | }; | |
957 | ||
958 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
959 | { | |
960 | return seq_open(file, &pwm_seq_ops); | |
961 | } | |
962 | ||
963 | static const struct file_operations pwm_debugfs_ops = { | |
964 | .owner = THIS_MODULE, | |
965 | .open = pwm_seq_open, | |
966 | .read = seq_read, | |
967 | .llseek = seq_lseek, | |
968 | .release = seq_release, | |
969 | }; | |
970 | ||
971 | static int __init pwm_debugfs_init(void) | |
972 | { | |
973 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
974 | &pwm_debugfs_ops); | |
975 | ||
976 | return 0; | |
977 | } | |
62099abf TR |
978 | subsys_initcall(pwm_debugfs_init); |
979 | #endif /* CONFIG_DEBUG_FS */ |