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]; | |
83a98864 | 78 | |
f051c466 | 79 | radix_tree_delete(&pwm_tree, pwm->pwm); |
0c2498f1 SH |
80 | } |
81 | ||
f051c466 TR |
82 | bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
83 | ||
84 | kfree(chip->pwms); | |
85 | chip->pwms = NULL; | |
86 | } | |
87 | ||
8138d2dd TR |
88 | static struct pwm_chip *pwmchip_find_by_name(const char *name) |
89 | { | |
90 | struct pwm_chip *chip; | |
91 | ||
92 | if (!name) | |
93 | return NULL; | |
94 | ||
95 | mutex_lock(&pwm_lock); | |
96 | ||
97 | list_for_each_entry(chip, &pwm_chips, list) { | |
98 | const char *chip_name = dev_name(chip->dev); | |
99 | ||
100 | if (chip_name && strcmp(chip_name, name) == 0) { | |
101 | mutex_unlock(&pwm_lock); | |
102 | return chip; | |
103 | } | |
104 | } | |
105 | ||
106 | mutex_unlock(&pwm_lock); | |
107 | ||
108 | return NULL; | |
109 | } | |
110 | ||
f051c466 TR |
111 | static int pwm_device_request(struct pwm_device *pwm, const char *label) |
112 | { | |
113 | int err; | |
114 | ||
115 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
116 | return -EBUSY; | |
117 | ||
118 | if (!try_module_get(pwm->chip->ops->owner)) | |
119 | return -ENODEV; | |
120 | ||
121 | if (pwm->chip->ops->request) { | |
122 | err = pwm->chip->ops->request(pwm->chip, pwm); | |
123 | if (err) { | |
124 | module_put(pwm->chip->ops->owner); | |
125 | return err; | |
126 | } | |
127 | } | |
128 | ||
129 | set_bit(PWMF_REQUESTED, &pwm->flags); | |
130 | pwm->label = label; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
83af2402 PA |
135 | struct pwm_device * |
136 | of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) | |
137 | { | |
138 | struct pwm_device *pwm; | |
139 | ||
140 | if (pc->of_pwm_n_cells < 3) | |
141 | return ERR_PTR(-EINVAL); | |
142 | ||
143 | if (args->args[0] >= pc->npwm) | |
144 | return ERR_PTR(-EINVAL); | |
145 | ||
146 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
147 | if (IS_ERR(pwm)) | |
148 | return pwm; | |
149 | ||
e39c0df1 | 150 | pwm->args.period = args->args[1]; |
83af2402 | 151 | |
208be769 | 152 | if (args->args[2] & PWM_POLARITY_INVERTED) |
e39c0df1 | 153 | pwm->args.polarity = PWM_POLARITY_INVERSED; |
83af2402 | 154 | else |
e39c0df1 | 155 | pwm->args.polarity = PWM_POLARITY_NORMAL; |
83af2402 PA |
156 | |
157 | return pwm; | |
158 | } | |
417328c3 | 159 | EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
83af2402 | 160 | |
e50d3523 SK |
161 | static struct pwm_device * |
162 | of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) | |
7299ab70 TR |
163 | { |
164 | struct pwm_device *pwm; | |
165 | ||
166 | if (pc->of_pwm_n_cells < 2) | |
167 | return ERR_PTR(-EINVAL); | |
168 | ||
169 | if (args->args[0] >= pc->npwm) | |
170 | return ERR_PTR(-EINVAL); | |
171 | ||
172 | pwm = pwm_request_from_chip(pc, args->args[0], NULL); | |
173 | if (IS_ERR(pwm)) | |
174 | return pwm; | |
175 | ||
e39c0df1 | 176 | pwm->args.period = args->args[1]; |
7299ab70 TR |
177 | |
178 | return pwm; | |
179 | } | |
180 | ||
dfeb86ec | 181 | static void of_pwmchip_add(struct pwm_chip *chip) |
7299ab70 TR |
182 | { |
183 | if (!chip->dev || !chip->dev->of_node) | |
184 | return; | |
185 | ||
186 | if (!chip->of_xlate) { | |
187 | chip->of_xlate = of_pwm_simple_xlate; | |
188 | chip->of_pwm_n_cells = 2; | |
189 | } | |
190 | ||
191 | of_node_get(chip->dev->of_node); | |
192 | } | |
193 | ||
dfeb86ec | 194 | static void of_pwmchip_remove(struct pwm_chip *chip) |
7299ab70 | 195 | { |
8d6cc073 | 196 | if (chip->dev) |
7299ab70 TR |
197 | of_node_put(chip->dev->of_node); |
198 | } | |
199 | ||
f051c466 TR |
200 | /** |
201 | * pwm_set_chip_data() - set private chip data for a PWM | |
202 | * @pwm: PWM device | |
203 | * @data: pointer to chip-specific data | |
04883802 TR |
204 | * |
205 | * Returns: 0 on success or a negative error code on failure. | |
f051c466 TR |
206 | */ |
207 | int pwm_set_chip_data(struct pwm_device *pwm, void *data) | |
208 | { | |
209 | if (!pwm) | |
210 | return -EINVAL; | |
211 | ||
212 | pwm->chip_data = data; | |
213 | ||
214 | return 0; | |
215 | } | |
928c4477 | 216 | EXPORT_SYMBOL_GPL(pwm_set_chip_data); |
f051c466 TR |
217 | |
218 | /** | |
219 | * pwm_get_chip_data() - get private chip data for a PWM | |
220 | * @pwm: PWM device | |
04883802 TR |
221 | * |
222 | * Returns: A pointer to the chip-private data for the PWM device. | |
f051c466 TR |
223 | */ |
224 | void *pwm_get_chip_data(struct pwm_device *pwm) | |
225 | { | |
226 | return pwm ? pwm->chip_data : NULL; | |
0c2498f1 | 227 | } |
928c4477 | 228 | EXPORT_SYMBOL_GPL(pwm_get_chip_data); |
0c2498f1 | 229 | |
5ec803ed BB |
230 | static bool pwm_ops_check(const struct pwm_ops *ops) |
231 | { | |
232 | /* driver supports legacy, non-atomic operation */ | |
233 | if (ops->config && ops->enable && ops->disable) | |
234 | return true; | |
235 | ||
236 | /* driver supports atomic operation */ | |
237 | if (ops->apply) | |
238 | return true; | |
239 | ||
240 | return false; | |
241 | } | |
242 | ||
0c2498f1 | 243 | /** |
b6a00fae | 244 | * pwmchip_add_with_polarity() - register a new PWM chip |
0c2498f1 | 245 | * @chip: the PWM chip to add |
b6a00fae | 246 | * @polarity: initial polarity of PWM channels |
f051c466 TR |
247 | * |
248 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
b6a00fae TK |
249 | * will be used. The initial polarity for all channels is specified by the |
250 | * @polarity parameter. | |
04883802 TR |
251 | * |
252 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 | 253 | */ |
b6a00fae TK |
254 | int pwmchip_add_with_polarity(struct pwm_chip *chip, |
255 | enum pwm_polarity polarity) | |
0c2498f1 SH |
256 | { |
257 | struct pwm_device *pwm; | |
f051c466 TR |
258 | unsigned int i; |
259 | int ret; | |
0c2498f1 | 260 | |
5ec803ed BB |
261 | if (!chip || !chip->dev || !chip->ops || !chip->npwm) |
262 | return -EINVAL; | |
263 | ||
264 | if (!pwm_ops_check(chip->ops)) | |
f051c466 | 265 | return -EINVAL; |
0c2498f1 SH |
266 | |
267 | mutex_lock(&pwm_lock); | |
268 | ||
f051c466 TR |
269 | ret = alloc_pwms(chip->base, chip->npwm); |
270 | if (ret < 0) | |
271 | goto out; | |
272 | ||
2907f8ab | 273 | chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL); |
f051c466 TR |
274 | if (!chip->pwms) { |
275 | ret = -ENOMEM; | |
0c2498f1 SH |
276 | goto out; |
277 | } | |
278 | ||
f051c466 TR |
279 | chip->base = ret; |
280 | ||
281 | for (i = 0; i < chip->npwm; i++) { | |
282 | pwm = &chip->pwms[i]; | |
283 | ||
284 | pwm->chip = chip; | |
285 | pwm->pwm = chip->base + i; | |
286 | pwm->hwpwm = i; | |
43a276b0 | 287 | pwm->state.polarity = polarity; |
0c2498f1 | 288 | |
15fa8a43 BB |
289 | if (chip->ops->get_state) |
290 | chip->ops->get_state(chip, pwm, &pwm->state); | |
0c2498f1 | 291 | |
f051c466 TR |
292 | radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
293 | } | |
294 | ||
295 | bitmap_set(allocated_pwms, chip->base, chip->npwm); | |
296 | ||
297 | INIT_LIST_HEAD(&chip->list); | |
298 | list_add(&chip->list, &pwm_chips); | |
0c2498f1 | 299 | |
f051c466 TR |
300 | ret = 0; |
301 | ||
7299ab70 TR |
302 | if (IS_ENABLED(CONFIG_OF)) |
303 | of_pwmchip_add(chip); | |
304 | ||
76abbdde HS |
305 | pwmchip_sysfs_export(chip); |
306 | ||
f051c466 TR |
307 | out: |
308 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
309 | return ret; |
310 | } | |
b6a00fae TK |
311 | EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); |
312 | ||
313 | /** | |
314 | * pwmchip_add() - register a new PWM chip | |
315 | * @chip: the PWM chip to add | |
316 | * | |
317 | * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base | |
318 | * will be used. The initial polarity for all channels is normal. | |
04883802 TR |
319 | * |
320 | * Returns: 0 on success or a negative error code on failure. | |
b6a00fae TK |
321 | */ |
322 | int pwmchip_add(struct pwm_chip *chip) | |
323 | { | |
324 | return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); | |
325 | } | |
0c2498f1 SH |
326 | EXPORT_SYMBOL_GPL(pwmchip_add); |
327 | ||
328 | /** | |
329 | * pwmchip_remove() - remove a PWM chip | |
330 | * @chip: the PWM chip to remove | |
331 | * | |
332 | * Removes a PWM chip. This function may return busy if the PWM chip provides | |
333 | * a PWM device that is still requested. | |
04883802 TR |
334 | * |
335 | * Returns: 0 on success or a negative error code on failure. | |
0c2498f1 SH |
336 | */ |
337 | int pwmchip_remove(struct pwm_chip *chip) | |
338 | { | |
f051c466 | 339 | unsigned int i; |
0c2498f1 SH |
340 | int ret = 0; |
341 | ||
342 | mutex_lock(&pwm_lock); | |
343 | ||
f051c466 TR |
344 | for (i = 0; i < chip->npwm; i++) { |
345 | struct pwm_device *pwm = &chip->pwms[i]; | |
0c2498f1 | 346 | |
f051c466 TR |
347 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
348 | ret = -EBUSY; | |
349 | goto out; | |
350 | } | |
0c2498f1 SH |
351 | } |
352 | ||
f051c466 | 353 | list_del_init(&chip->list); |
7299ab70 TR |
354 | |
355 | if (IS_ENABLED(CONFIG_OF)) | |
356 | of_pwmchip_remove(chip); | |
357 | ||
f051c466 | 358 | free_pwms(chip); |
0c2498f1 | 359 | |
76abbdde HS |
360 | pwmchip_sysfs_unexport(chip); |
361 | ||
0c2498f1 SH |
362 | out: |
363 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
364 | return ret; |
365 | } | |
366 | EXPORT_SYMBOL_GPL(pwmchip_remove); | |
367 | ||
368 | /** | |
369 | * pwm_request() - request a PWM device | |
04883802 | 370 | * @pwm: global PWM device index |
0c2498f1 | 371 | * @label: PWM device label |
8138d2dd TR |
372 | * |
373 | * This function is deprecated, use pwm_get() instead. | |
04883802 TR |
374 | * |
375 | * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on | |
376 | * failure. | |
0c2498f1 | 377 | */ |
f051c466 | 378 | struct pwm_device *pwm_request(int pwm, const char *label) |
0c2498f1 | 379 | { |
f051c466 TR |
380 | struct pwm_device *dev; |
381 | int err; | |
382 | ||
383 | if (pwm < 0 || pwm >= MAX_PWMS) | |
384 | return ERR_PTR(-EINVAL); | |
0c2498f1 SH |
385 | |
386 | mutex_lock(&pwm_lock); | |
387 | ||
f051c466 TR |
388 | dev = pwm_to_device(pwm); |
389 | if (!dev) { | |
390 | dev = ERR_PTR(-EPROBE_DEFER); | |
0c2498f1 SH |
391 | goto out; |
392 | } | |
393 | ||
f051c466 TR |
394 | err = pwm_device_request(dev, label); |
395 | if (err < 0) | |
396 | dev = ERR_PTR(err); | |
0c2498f1 | 397 | |
f051c466 TR |
398 | out: |
399 | mutex_unlock(&pwm_lock); | |
0c2498f1 | 400 | |
f051c466 TR |
401 | return dev; |
402 | } | |
403 | EXPORT_SYMBOL_GPL(pwm_request); | |
0c2498f1 | 404 | |
f051c466 TR |
405 | /** |
406 | * pwm_request_from_chip() - request a PWM device relative to a PWM chip | |
407 | * @chip: PWM chip | |
408 | * @index: per-chip index of the PWM to request | |
409 | * @label: a literal description string of this PWM | |
410 | * | |
04883802 TR |
411 | * Returns: A pointer to the PWM device at the given index of the given PWM |
412 | * chip. A negative error code is returned if the index is not valid for the | |
413 | * specified PWM chip or if the PWM device cannot be requested. | |
f051c466 TR |
414 | */ |
415 | struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, | |
416 | unsigned int index, | |
417 | const char *label) | |
418 | { | |
419 | struct pwm_device *pwm; | |
420 | int err; | |
0c2498f1 | 421 | |
f051c466 TR |
422 | if (!chip || index >= chip->npwm) |
423 | return ERR_PTR(-EINVAL); | |
0c2498f1 | 424 | |
f051c466 TR |
425 | mutex_lock(&pwm_lock); |
426 | pwm = &chip->pwms[index]; | |
0c2498f1 | 427 | |
f051c466 TR |
428 | err = pwm_device_request(pwm, label); |
429 | if (err < 0) | |
430 | pwm = ERR_PTR(err); | |
431 | ||
432 | mutex_unlock(&pwm_lock); | |
0c2498f1 SH |
433 | return pwm; |
434 | } | |
f051c466 | 435 | EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
0c2498f1 SH |
436 | |
437 | /** | |
438 | * pwm_free() - free a PWM device | |
439 | * @pwm: PWM device | |
8138d2dd TR |
440 | * |
441 | * This function is deprecated, use pwm_put() instead. | |
0c2498f1 SH |
442 | */ |
443 | void pwm_free(struct pwm_device *pwm) | |
444 | { | |
8138d2dd | 445 | pwm_put(pwm); |
0c2498f1 SH |
446 | } |
447 | EXPORT_SYMBOL_GPL(pwm_free); | |
448 | ||
449 | /** | |
5ec803ed | 450 | * pwm_apply_state() - atomically apply a new state to a PWM device |
0c2498f1 | 451 | * @pwm: PWM device |
5ec803ed BB |
452 | * @state: new state to apply. This can be adjusted by the PWM driver |
453 | * if the requested config is not achievable, for example, | |
454 | * ->duty_cycle and ->period might be approximated. | |
0c2498f1 | 455 | */ |
5ec803ed | 456 | int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state) |
0c2498f1 | 457 | { |
76abbdde HS |
458 | int err; |
459 | ||
ef2bf499 BN |
460 | if (!pwm || !state || !state->period || |
461 | state->duty_cycle > state->period) | |
f051c466 TR |
462 | return -EINVAL; |
463 | ||
5ec803ed BB |
464 | if (!memcmp(state, &pwm->state, sizeof(*state))) |
465 | return 0; | |
76abbdde | 466 | |
5ec803ed BB |
467 | if (pwm->chip->ops->apply) { |
468 | err = pwm->chip->ops->apply(pwm->chip, pwm, state); | |
469 | if (err) | |
470 | return err; | |
0c2498f1 | 471 | |
5ec803ed BB |
472 | pwm->state = *state; |
473 | } else { | |
474 | /* | |
475 | * FIXME: restore the initial state in case of error. | |
476 | */ | |
477 | if (state->polarity != pwm->state.polarity) { | |
478 | if (!pwm->chip->ops->set_polarity) | |
479 | return -ENOTSUPP; | |
480 | ||
481 | /* | |
482 | * Changing the polarity of a running PWM is | |
483 | * only allowed when the PWM driver implements | |
484 | * ->apply(). | |
485 | */ | |
486 | if (pwm->state.enabled) { | |
487 | pwm->chip->ops->disable(pwm->chip, pwm); | |
488 | pwm->state.enabled = false; | |
489 | } | |
490 | ||
491 | err = pwm->chip->ops->set_polarity(pwm->chip, pwm, | |
492 | state->polarity); | |
493 | if (err) | |
494 | return err; | |
495 | ||
496 | pwm->state.polarity = state->polarity; | |
497 | } | |
76abbdde | 498 | |
5ec803ed BB |
499 | if (state->period != pwm->state.period || |
500 | state->duty_cycle != pwm->state.duty_cycle) { | |
501 | err = pwm->chip->ops->config(pwm->chip, pwm, | |
502 | state->duty_cycle, | |
503 | state->period); | |
504 | if (err) | |
505 | return err; | |
0aa0869c | 506 | |
5ec803ed BB |
507 | pwm->state.duty_cycle = state->duty_cycle; |
508 | pwm->state.period = state->period; | |
509 | } | |
0aa0869c | 510 | |
5ec803ed BB |
511 | if (state->enabled != pwm->state.enabled) { |
512 | if (state->enabled) { | |
513 | err = pwm->chip->ops->enable(pwm->chip, pwm); | |
514 | if (err) | |
515 | return err; | |
516 | } else { | |
517 | pwm->chip->ops->disable(pwm->chip, pwm); | |
518 | } | |
d1cd2142 | 519 | |
5ec803ed BB |
520 | pwm->state.enabled = state->enabled; |
521 | } | |
d1cd2142 | 522 | } |
0aa0869c | 523 | |
459a25af | 524 | return 0; |
0aa0869c | 525 | } |
5ec803ed | 526 | EXPORT_SYMBOL_GPL(pwm_apply_state); |
0aa0869c | 527 | |
3a3d1a4e LJ |
528 | /** |
529 | * pwm_capture() - capture and report a PWM signal | |
530 | * @pwm: PWM device | |
531 | * @result: structure to fill with capture result | |
532 | * @timeout: time to wait, in milliseconds, before giving up on capture | |
533 | * | |
534 | * Returns: 0 on success or a negative error code on failure. | |
535 | */ | |
536 | int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, | |
537 | unsigned long timeout) | |
538 | { | |
539 | int err; | |
540 | ||
541 | if (!pwm || !pwm->chip->ops) | |
542 | return -EINVAL; | |
543 | ||
544 | if (!pwm->chip->ops->capture) | |
545 | return -ENOSYS; | |
546 | ||
547 | mutex_lock(&pwm_lock); | |
548 | err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout); | |
549 | mutex_unlock(&pwm_lock); | |
550 | ||
551 | return err; | |
552 | } | |
553 | EXPORT_SYMBOL_GPL(pwm_capture); | |
554 | ||
0c2498f1 | 555 | /** |
5ec803ed | 556 | * pwm_adjust_config() - adjust the current PWM config to the PWM arguments |
0c2498f1 | 557 | * @pwm: PWM device |
04883802 | 558 | * |
5ec803ed BB |
559 | * This function will adjust the PWM config to the PWM arguments provided |
560 | * by the DT or PWM lookup table. This is particularly useful to adapt | |
561 | * the bootloader config to the Linux one. | |
0c2498f1 | 562 | */ |
5ec803ed | 563 | int pwm_adjust_config(struct pwm_device *pwm) |
0c2498f1 | 564 | { |
5ec803ed BB |
565 | struct pwm_state state; |
566 | struct pwm_args pargs; | |
d1cd2142 | 567 | |
5ec803ed BB |
568 | pwm_get_args(pwm, &pargs); |
569 | pwm_get_state(pwm, &state); | |
d1cd2142 | 570 | |
5ec803ed BB |
571 | /* |
572 | * If the current period is zero it means that either the PWM driver | |
573 | * does not support initial state retrieval or the PWM has not yet | |
574 | * been configured. | |
575 | * | |
576 | * In either case, we setup the new period and polarity, and assign a | |
577 | * duty cycle of 0. | |
578 | */ | |
579 | if (!state.period) { | |
580 | state.duty_cycle = 0; | |
581 | state.period = pargs.period; | |
582 | state.polarity = pargs.polarity; | |
d1cd2142 | 583 | |
5ec803ed | 584 | return pwm_apply_state(pwm, &state); |
d1cd2142 JR |
585 | } |
586 | ||
5ec803ed BB |
587 | /* |
588 | * Adjust the PWM duty cycle/period based on the period value provided | |
589 | * in PWM args. | |
590 | */ | |
591 | if (pargs.period != state.period) { | |
592 | u64 dutycycle = (u64)state.duty_cycle * pargs.period; | |
0c2498f1 | 593 | |
5ec803ed BB |
594 | do_div(dutycycle, state.period); |
595 | state.duty_cycle = dutycycle; | |
596 | state.period = pargs.period; | |
597 | } | |
0c2498f1 | 598 | |
5ec803ed BB |
599 | /* |
600 | * If the polarity changed, we should also change the duty cycle. | |
601 | */ | |
602 | if (pargs.polarity != state.polarity) { | |
603 | state.polarity = pargs.polarity; | |
604 | state.duty_cycle = state.period - state.duty_cycle; | |
09a7e4a3 | 605 | } |
5ec803ed BB |
606 | |
607 | return pwm_apply_state(pwm, &state); | |
0c2498f1 | 608 | } |
5ec803ed | 609 | EXPORT_SYMBOL_GPL(pwm_adjust_config); |
62099abf | 610 | |
7299ab70 TR |
611 | static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
612 | { | |
613 | struct pwm_chip *chip; | |
614 | ||
615 | mutex_lock(&pwm_lock); | |
616 | ||
617 | list_for_each_entry(chip, &pwm_chips, list) | |
618 | if (chip->dev && chip->dev->of_node == np) { | |
619 | mutex_unlock(&pwm_lock); | |
620 | return chip; | |
621 | } | |
622 | ||
623 | mutex_unlock(&pwm_lock); | |
624 | ||
625 | return ERR_PTR(-EPROBE_DEFER); | |
626 | } | |
627 | ||
628 | /** | |
8eb96127 | 629 | * of_pwm_get() - request a PWM via the PWM framework |
7299ab70 TR |
630 | * @np: device node to get the PWM from |
631 | * @con_id: consumer name | |
632 | * | |
633 | * Returns the PWM device parsed from the phandle and index specified in the | |
634 | * "pwms" property of a device tree node or a negative error-code on failure. | |
635 | * Values parsed from the device tree are stored in the returned PWM device | |
636 | * object. | |
637 | * | |
638 | * If con_id is NULL, the first PWM device listed in the "pwms" property will | |
639 | * be requested. Otherwise the "pwm-names" property is used to do a reverse | |
640 | * lookup of the PWM index. This also means that the "pwm-names" property | |
641 | * becomes mandatory for devices that look up the PWM device via the con_id | |
642 | * parameter. | |
04883802 TR |
643 | * |
644 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
645 | * error code on failure. | |
7299ab70 | 646 | */ |
8eb96127 | 647 | struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id) |
7299ab70 TR |
648 | { |
649 | struct pwm_device *pwm = NULL; | |
650 | struct of_phandle_args args; | |
651 | struct pwm_chip *pc; | |
652 | int index = 0; | |
653 | int err; | |
654 | ||
655 | if (con_id) { | |
656 | index = of_property_match_string(np, "pwm-names", con_id); | |
657 | if (index < 0) | |
658 | return ERR_PTR(index); | |
659 | } | |
660 | ||
661 | err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, | |
662 | &args); | |
663 | if (err) { | |
664 | pr_debug("%s(): can't parse \"pwms\" property\n", __func__); | |
665 | return ERR_PTR(err); | |
666 | } | |
667 | ||
668 | pc = of_node_to_pwmchip(args.np); | |
669 | if (IS_ERR(pc)) { | |
670 | pr_debug("%s(): PWM chip not found\n", __func__); | |
671 | pwm = ERR_CAST(pc); | |
672 | goto put; | |
673 | } | |
674 | ||
675 | if (args.args_count != pc->of_pwm_n_cells) { | |
676 | pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, | |
677 | args.np->full_name); | |
678 | pwm = ERR_PTR(-EINVAL); | |
679 | goto put; | |
680 | } | |
681 | ||
682 | pwm = pc->of_xlate(pc, &args); | |
683 | if (IS_ERR(pwm)) | |
684 | goto put; | |
685 | ||
686 | /* | |
687 | * If a consumer name was not given, try to look it up from the | |
688 | * "pwm-names" property if it exists. Otherwise use the name of | |
689 | * the user device node. | |
690 | */ | |
691 | if (!con_id) { | |
692 | err = of_property_read_string_index(np, "pwm-names", index, | |
693 | &con_id); | |
694 | if (err < 0) | |
695 | con_id = np->name; | |
696 | } | |
697 | ||
698 | pwm->label = con_id; | |
699 | ||
700 | put: | |
701 | of_node_put(args.np); | |
702 | ||
703 | return pwm; | |
704 | } | |
8eb96127 | 705 | EXPORT_SYMBOL_GPL(of_pwm_get); |
7299ab70 | 706 | |
8138d2dd TR |
707 | /** |
708 | * pwm_add_table() - register PWM device consumers | |
709 | * @table: array of consumers to register | |
710 | * @num: number of consumers in table | |
711 | */ | |
c264f111 | 712 | void pwm_add_table(struct pwm_lookup *table, size_t num) |
8138d2dd TR |
713 | { |
714 | mutex_lock(&pwm_lookup_lock); | |
715 | ||
716 | while (num--) { | |
717 | list_add_tail(&table->list, &pwm_lookup_list); | |
718 | table++; | |
719 | } | |
720 | ||
721 | mutex_unlock(&pwm_lookup_lock); | |
722 | } | |
723 | ||
efb0de55 SK |
724 | /** |
725 | * pwm_remove_table() - unregister PWM device consumers | |
726 | * @table: array of consumers to unregister | |
727 | * @num: number of consumers in table | |
728 | */ | |
729 | void pwm_remove_table(struct pwm_lookup *table, size_t num) | |
730 | { | |
731 | mutex_lock(&pwm_lookup_lock); | |
732 | ||
733 | while (num--) { | |
734 | list_del(&table->list); | |
735 | table++; | |
736 | } | |
737 | ||
738 | mutex_unlock(&pwm_lookup_lock); | |
739 | } | |
740 | ||
8138d2dd TR |
741 | /** |
742 | * pwm_get() - look up and request a PWM device | |
743 | * @dev: device for PWM consumer | |
744 | * @con_id: consumer name | |
745 | * | |
7299ab70 TR |
746 | * Lookup is first attempted using DT. If the device was not instantiated from |
747 | * a device tree, a PWM chip and a relative index is looked up via a table | |
748 | * supplied by board setup code (see pwm_add_table()). | |
8138d2dd TR |
749 | * |
750 | * Once a PWM chip has been found the specified PWM device will be requested | |
751 | * and is ready to be used. | |
04883802 TR |
752 | * |
753 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
754 | * error code on failure. | |
8138d2dd TR |
755 | */ |
756 | struct pwm_device *pwm_get(struct device *dev, const char *con_id) | |
757 | { | |
758 | struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); | |
e50d3523 | 759 | const char *dev_id = dev ? dev_name(dev) : NULL; |
8138d2dd TR |
760 | struct pwm_chip *chip = NULL; |
761 | unsigned int best = 0; | |
70145f87 | 762 | struct pwm_lookup *p, *chosen = NULL; |
8138d2dd TR |
763 | unsigned int match; |
764 | ||
7299ab70 TR |
765 | /* look up via DT first */ |
766 | if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) | |
8eb96127 | 767 | return of_pwm_get(dev->of_node, con_id); |
7299ab70 | 768 | |
8138d2dd TR |
769 | /* |
770 | * We look up the provider in the static table typically provided by | |
771 | * board setup code. We first try to lookup the consumer device by | |
772 | * name. If the consumer device was passed in as NULL or if no match | |
773 | * was found, we try to find the consumer by directly looking it up | |
774 | * by name. | |
775 | * | |
776 | * If a match is found, the provider PWM chip is looked up by name | |
777 | * and a PWM device is requested using the PWM device per-chip index. | |
778 | * | |
779 | * The lookup algorithm was shamelessly taken from the clock | |
780 | * framework: | |
781 | * | |
782 | * We do slightly fuzzy matching here: | |
783 | * An entry with a NULL ID is assumed to be a wildcard. | |
784 | * If an entry has a device ID, it must match | |
785 | * If an entry has a connection ID, it must match | |
786 | * Then we take the most specific entry - with the following order | |
787 | * of precedence: dev+con > dev only > con only. | |
788 | */ | |
789 | mutex_lock(&pwm_lookup_lock); | |
790 | ||
791 | list_for_each_entry(p, &pwm_lookup_list, list) { | |
792 | match = 0; | |
793 | ||
794 | if (p->dev_id) { | |
795 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
796 | continue; | |
797 | ||
798 | match += 2; | |
799 | } | |
800 | ||
801 | if (p->con_id) { | |
802 | if (!con_id || strcmp(p->con_id, con_id)) | |
803 | continue; | |
804 | ||
805 | match += 1; | |
806 | } | |
807 | ||
808 | if (match > best) { | |
70145f87 | 809 | chosen = p; |
8138d2dd TR |
810 | |
811 | if (match != 3) | |
812 | best = match; | |
813 | else | |
814 | break; | |
815 | } | |
816 | } | |
817 | ||
655a0355 TR |
818 | if (!chosen) { |
819 | pwm = ERR_PTR(-ENODEV); | |
70145f87 | 820 | goto out; |
655a0355 | 821 | } |
3796ce1d | 822 | |
70145f87 GU |
823 | chip = pwmchip_find_by_name(chosen->provider); |
824 | if (!chip) | |
825 | goto out; | |
3796ce1d | 826 | |
70145f87 GU |
827 | pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
828 | if (IS_ERR(pwm)) | |
829 | goto out; | |
8138d2dd | 830 | |
fbd45a12 BB |
831 | pwm->args.period = chosen->period; |
832 | pwm->args.polarity = chosen->polarity; | |
833 | ||
70145f87 GU |
834 | out: |
835 | mutex_unlock(&pwm_lookup_lock); | |
8138d2dd TR |
836 | return pwm; |
837 | } | |
838 | EXPORT_SYMBOL_GPL(pwm_get); | |
839 | ||
840 | /** | |
841 | * pwm_put() - release a PWM device | |
842 | * @pwm: PWM device | |
843 | */ | |
844 | void pwm_put(struct pwm_device *pwm) | |
845 | { | |
846 | if (!pwm) | |
847 | return; | |
848 | ||
849 | mutex_lock(&pwm_lock); | |
850 | ||
851 | if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { | |
e50d3523 | 852 | pr_warn("PWM device already freed\n"); |
8138d2dd TR |
853 | goto out; |
854 | } | |
855 | ||
856 | if (pwm->chip->ops->free) | |
857 | pwm->chip->ops->free(pwm->chip, pwm); | |
858 | ||
859 | pwm->label = NULL; | |
860 | ||
861 | module_put(pwm->chip->ops->owner); | |
862 | out: | |
863 | mutex_unlock(&pwm_lock); | |
864 | } | |
865 | EXPORT_SYMBOL_GPL(pwm_put); | |
866 | ||
6354316d AC |
867 | static void devm_pwm_release(struct device *dev, void *res) |
868 | { | |
869 | pwm_put(*(struct pwm_device **)res); | |
870 | } | |
871 | ||
872 | /** | |
873 | * devm_pwm_get() - resource managed pwm_get() | |
874 | * @dev: device for PWM consumer | |
875 | * @con_id: consumer name | |
876 | * | |
877 | * This function performs like pwm_get() but the acquired PWM device will | |
878 | * automatically be released on driver detach. | |
04883802 TR |
879 | * |
880 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
881 | * error code on failure. | |
6354316d AC |
882 | */ |
883 | struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) | |
884 | { | |
885 | struct pwm_device **ptr, *pwm; | |
886 | ||
77f0b9d2 | 887 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
6354316d AC |
888 | if (!ptr) |
889 | return ERR_PTR(-ENOMEM); | |
890 | ||
891 | pwm = pwm_get(dev, con_id); | |
892 | if (!IS_ERR(pwm)) { | |
893 | *ptr = pwm; | |
894 | devres_add(dev, ptr); | |
895 | } else { | |
896 | devres_free(ptr); | |
897 | } | |
898 | ||
899 | return pwm; | |
900 | } | |
901 | EXPORT_SYMBOL_GPL(devm_pwm_get); | |
902 | ||
261a5edd PU |
903 | /** |
904 | * devm_of_pwm_get() - resource managed of_pwm_get() | |
905 | * @dev: device for PWM consumer | |
906 | * @np: device node to get the PWM from | |
907 | * @con_id: consumer name | |
908 | * | |
909 | * This function performs like of_pwm_get() but the acquired PWM device will | |
910 | * automatically be released on driver detach. | |
04883802 TR |
911 | * |
912 | * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded | |
913 | * error code on failure. | |
261a5edd PU |
914 | */ |
915 | struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, | |
916 | const char *con_id) | |
917 | { | |
918 | struct pwm_device **ptr, *pwm; | |
919 | ||
77f0b9d2 | 920 | ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
261a5edd PU |
921 | if (!ptr) |
922 | return ERR_PTR(-ENOMEM); | |
923 | ||
924 | pwm = of_pwm_get(np, con_id); | |
925 | if (!IS_ERR(pwm)) { | |
926 | *ptr = pwm; | |
927 | devres_add(dev, ptr); | |
928 | } else { | |
929 | devres_free(ptr); | |
930 | } | |
931 | ||
932 | return pwm; | |
933 | } | |
934 | EXPORT_SYMBOL_GPL(devm_of_pwm_get); | |
935 | ||
6354316d AC |
936 | static int devm_pwm_match(struct device *dev, void *res, void *data) |
937 | { | |
938 | struct pwm_device **p = res; | |
939 | ||
940 | if (WARN_ON(!p || !*p)) | |
941 | return 0; | |
942 | ||
943 | return *p == data; | |
944 | } | |
945 | ||
946 | /** | |
947 | * devm_pwm_put() - resource managed pwm_put() | |
948 | * @dev: device for PWM consumer | |
949 | * @pwm: PWM device | |
950 | * | |
951 | * Release a PWM previously allocated using devm_pwm_get(). Calling this | |
952 | * function is usually not needed because devm-allocated resources are | |
953 | * automatically released on driver detach. | |
954 | */ | |
955 | void devm_pwm_put(struct device *dev, struct pwm_device *pwm) | |
956 | { | |
957 | WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); | |
958 | } | |
959 | EXPORT_SYMBOL_GPL(devm_pwm_put); | |
960 | ||
6e69ab13 FV |
961 | /** |
962 | * pwm_can_sleep() - report whether PWM access will sleep | |
963 | * @pwm: PWM device | |
964 | * | |
04883802 | 965 | * Returns: True if accessing the PWM can sleep, false otherwise. |
6e69ab13 FV |
966 | */ |
967 | bool pwm_can_sleep(struct pwm_device *pwm) | |
968 | { | |
ff01c944 | 969 | return true; |
6e69ab13 FV |
970 | } |
971 | EXPORT_SYMBOL_GPL(pwm_can_sleep); | |
972 | ||
62099abf TR |
973 | #ifdef CONFIG_DEBUG_FS |
974 | static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) | |
975 | { | |
976 | unsigned int i; | |
977 | ||
978 | for (i = 0; i < chip->npwm; i++) { | |
979 | struct pwm_device *pwm = &chip->pwms[i]; | |
39100cee BB |
980 | struct pwm_state state; |
981 | ||
982 | pwm_get_state(pwm, &state); | |
62099abf TR |
983 | |
984 | seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); | |
985 | ||
986 | if (test_bit(PWMF_REQUESTED, &pwm->flags)) | |
adcba1e3 | 987 | seq_puts(s, " requested"); |
62099abf | 988 | |
39100cee | 989 | if (state.enabled) |
adcba1e3 | 990 | seq_puts(s, " enabled"); |
62099abf | 991 | |
23e3523f HS |
992 | seq_printf(s, " period: %u ns", state.period); |
993 | seq_printf(s, " duty: %u ns", state.duty_cycle); | |
994 | seq_printf(s, " polarity: %s", | |
995 | state.polarity ? "inverse" : "normal"); | |
996 | ||
adcba1e3 | 997 | seq_puts(s, "\n"); |
62099abf TR |
998 | } |
999 | } | |
1000 | ||
1001 | static void *pwm_seq_start(struct seq_file *s, loff_t *pos) | |
1002 | { | |
1003 | mutex_lock(&pwm_lock); | |
1004 | s->private = ""; | |
1005 | ||
1006 | return seq_list_start(&pwm_chips, *pos); | |
1007 | } | |
1008 | ||
1009 | static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1010 | { | |
1011 | s->private = "\n"; | |
1012 | ||
1013 | return seq_list_next(v, &pwm_chips, pos); | |
1014 | } | |
1015 | ||
1016 | static void pwm_seq_stop(struct seq_file *s, void *v) | |
1017 | { | |
1018 | mutex_unlock(&pwm_lock); | |
1019 | } | |
1020 | ||
1021 | static int pwm_seq_show(struct seq_file *s, void *v) | |
1022 | { | |
1023 | struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); | |
1024 | ||
1025 | seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, | |
1026 | chip->dev->bus ? chip->dev->bus->name : "no-bus", | |
1027 | dev_name(chip->dev), chip->npwm, | |
1028 | (chip->npwm != 1) ? "s" : ""); | |
1029 | ||
1030 | if (chip->ops->dbg_show) | |
1031 | chip->ops->dbg_show(chip, s); | |
1032 | else | |
1033 | pwm_dbg_show(chip, s); | |
1034 | ||
1035 | return 0; | |
1036 | } | |
1037 | ||
1038 | static const struct seq_operations pwm_seq_ops = { | |
1039 | .start = pwm_seq_start, | |
1040 | .next = pwm_seq_next, | |
1041 | .stop = pwm_seq_stop, | |
1042 | .show = pwm_seq_show, | |
1043 | }; | |
1044 | ||
1045 | static int pwm_seq_open(struct inode *inode, struct file *file) | |
1046 | { | |
1047 | return seq_open(file, &pwm_seq_ops); | |
1048 | } | |
1049 | ||
1050 | static const struct file_operations pwm_debugfs_ops = { | |
1051 | .owner = THIS_MODULE, | |
1052 | .open = pwm_seq_open, | |
1053 | .read = seq_read, | |
1054 | .llseek = seq_lseek, | |
1055 | .release = seq_release, | |
1056 | }; | |
1057 | ||
1058 | static int __init pwm_debugfs_init(void) | |
1059 | { | |
1060 | debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, | |
1061 | &pwm_debugfs_ops); | |
1062 | ||
1063 | return 0; | |
1064 | } | |
62099abf TR |
1065 | subsys_initcall(pwm_debugfs_init); |
1066 | #endif /* CONFIG_DEBUG_FS */ |