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Sascha Hauer0c2498f2011-01-28 09:40:40 +01001/*
2 * Generic pwmlib implementation
3 *
4 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
Thierry Redingf051c462011-12-14 11:12:23 +01005 * Copyright (C) 2011-2012 Avionic Design GmbH
Sascha Hauer0c2498f2011-01-28 09:40:40 +01006 *
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>
Thierry Redingf051c462011-12-14 11:12:23 +010024#include <linux/radix-tree.h>
Sascha Hauer0c2498f2011-01-28 09:40:40 +010025#include <linux/list.h>
26#include <linux/mutex.h>
27#include <linux/err.h>
28#include <linux/slab.h>
29#include <linux/device.h>
Thierry Reding62099ab2012-03-26 09:31:48 +020030#include <linux/debugfs.h>
31#include <linux/seq_file.h>
Sascha Hauer0c2498f2011-01-28 09:40:40 +010032
Laurent Pinchart208be762013-07-18 00:54:22 +020033#include <dt-bindings/pwm/pwm.h>
Sascha Hauer0c2498f2011-01-28 09:40:40 +010034
Laurent Pinchart208be762013-07-18 00:54:22 +020035#define MAX_PWMS 1024
Philip, Avinash83af2402012-11-21 13:10:44 +053036
Thierry Reding8138d2d2012-03-26 08:42:48 +020037static DEFINE_MUTEX(pwm_lookup_lock);
38static LIST_HEAD(pwm_lookup_list);
Sascha Hauer0c2498f2011-01-28 09:40:40 +010039static DEFINE_MUTEX(pwm_lock);
Thierry Redingf051c462011-12-14 11:12:23 +010040static LIST_HEAD(pwm_chips);
41static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42static RADIX_TREE(pwm_tree, GFP_KERNEL);
Sascha Hauer0c2498f2011-01-28 09:40:40 +010043
Thierry Redingf051c462011-12-14 11:12:23 +010044static struct pwm_device *pwm_to_device(unsigned int pwm)
Sascha Hauer0c2498f2011-01-28 09:40:40 +010045{
Thierry Redingf051c462011-12-14 11:12:23 +010046 return radix_tree_lookup(&pwm_tree, pwm);
47}
Sascha Hauer0c2498f2011-01-28 09:40:40 +010048
Thierry Redingf051c462011-12-14 11:12:23 +010049static 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;
59
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
72static 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);
Sascha Hauer0c2498f2011-01-28 09:40:40 +010079 }
80
Thierry Redingf051c462011-12-14 11:12:23 +010081 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
82
83 kfree(chip->pwms);
84 chip->pwms = NULL;
85}
86
Thierry Reding8138d2d2012-03-26 08:42:48 +020087static 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
Thierry Redingf051c462011-12-14 11:12:23 +0100110static 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
Philip, Avinash83af2402012-11-21 13:10:44 +0530134struct pwm_device *
135of_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
Laurent Pinchart208be762013-07-18 00:54:22 +0200151 if (args->args[2] & PWM_POLARITY_INVERTED)
Philip, Avinash83af2402012-11-21 13:10:44 +0530152 pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
153 else
154 pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
155
156 return pwm;
157}
Thierry Reding417328c2012-11-28 15:12:07 +0100158EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
Philip, Avinash83af2402012-11-21 13:10:44 +0530159
Sachin Kamate50d3522012-08-10 16:41:13 +0530160static struct pwm_device *
161of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
Thierry Reding7299ab72011-12-14 11:10:32 +0100162{
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
Sachin Kamatdfeb86e2012-08-02 12:32:42 +0530180static void of_pwmchip_add(struct pwm_chip *chip)
Thierry Reding7299ab72011-12-14 11:10:32 +0100181{
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
Sachin Kamatdfeb86e2012-08-02 12:32:42 +0530193static void of_pwmchip_remove(struct pwm_chip *chip)
Thierry Reding7299ab72011-12-14 11:10:32 +0100194{
Markus Elfring8d6cc072015-02-03 11:54:28 +0100195 if (chip->dev)
Thierry Reding7299ab72011-12-14 11:10:32 +0100196 of_node_put(chip->dev->of_node);
197}
198
Thierry Redingf051c462011-12-14 11:12:23 +0100199/**
200 * pwm_set_chip_data() - set private chip data for a PWM
201 * @pwm: PWM device
202 * @data: pointer to chip-specific data
Thierry Reding04883802015-07-27 11:58:32 +0200203 *
204 * Returns: 0 on success or a negative error code on failure.
Thierry Redingf051c462011-12-14 11:12:23 +0100205 */
206int 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}
Thierry Reding928c4472013-01-30 09:22:24 +0100215EXPORT_SYMBOL_GPL(pwm_set_chip_data);
Thierry Redingf051c462011-12-14 11:12:23 +0100216
217/**
218 * pwm_get_chip_data() - get private chip data for a PWM
219 * @pwm: PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200220 *
221 * Returns: A pointer to the chip-private data for the PWM device.
Thierry Redingf051c462011-12-14 11:12:23 +0100222 */
223void *pwm_get_chip_data(struct pwm_device *pwm)
224{
225 return pwm ? pwm->chip_data : NULL;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100226}
Thierry Reding928c4472013-01-30 09:22:24 +0100227EXPORT_SYMBOL_GPL(pwm_get_chip_data);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100228
229/**
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700230 * pwmchip_add_with_polarity() - register a new PWM chip
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100231 * @chip: the PWM chip to add
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700232 * @polarity: initial polarity of PWM channels
Thierry Redingf051c462011-12-14 11:12:23 +0100233 *
234 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700235 * will be used. The initial polarity for all channels is specified by the
236 * @polarity parameter.
Thierry Reding04883802015-07-27 11:58:32 +0200237 *
238 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100239 */
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700240int pwmchip_add_with_polarity(struct pwm_chip *chip,
241 enum pwm_polarity polarity)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100242{
243 struct pwm_device *pwm;
Thierry Redingf051c462011-12-14 11:12:23 +0100244 unsigned int i;
245 int ret;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100246
Thierry Redingf051c462011-12-14 11:12:23 +0100247 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
Xiubo Li533acc02014-08-18 17:08:44 +0800248 !chip->ops->enable || !chip->ops->disable || !chip->npwm)
Thierry Redingf051c462011-12-14 11:12:23 +0100249 return -EINVAL;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100250
251 mutex_lock(&pwm_lock);
252
Thierry Redingf051c462011-12-14 11:12:23 +0100253 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;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100260 goto out;
261 }
262
Thierry Redingf051c462011-12-14 11:12:23 +0100263 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;
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700271 pwm->polarity = polarity;
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700272 mutex_init(&pwm->lock);
Thierry Redingf051c462011-12-14 11:12:23 +0100273
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);
281
282 ret = 0;
283
Thierry Reding7299ab72011-12-14 11:10:32 +0100284 if (IS_ENABLED(CONFIG_OF))
285 of_pwmchip_add(chip);
286
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700287 pwmchip_sysfs_export(chip);
288
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100289out:
290 mutex_unlock(&pwm_lock);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100291 return ret;
292}
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700293EXPORT_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.
Thierry Reding04883802015-07-27 11:58:32 +0200301 *
302 * Returns: 0 on success or a negative error code on failure.
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700303 */
304int pwmchip_add(struct pwm_chip *chip)
305{
306 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
307}
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100308EXPORT_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.
Thierry Reding04883802015-07-27 11:58:32 +0200316 *
317 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100318 */
319int pwmchip_remove(struct pwm_chip *chip)
320{
Thierry Redingf051c462011-12-14 11:12:23 +0100321 unsigned int i;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100322 int ret = 0;
323
324 mutex_lock(&pwm_lock);
325
Thierry Redingf051c462011-12-14 11:12:23 +0100326 for (i = 0; i < chip->npwm; i++) {
327 struct pwm_device *pwm = &chip->pwms[i];
328
329 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
330 ret = -EBUSY;
331 goto out;
332 }
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100333 }
334
Thierry Redingf051c462011-12-14 11:12:23 +0100335 list_del_init(&chip->list);
Thierry Reding7299ab72011-12-14 11:10:32 +0100336
337 if (IS_ENABLED(CONFIG_OF))
338 of_pwmchip_remove(chip);
339
Thierry Redingf051c462011-12-14 11:12:23 +0100340 free_pwms(chip);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100341
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700342 pwmchip_sysfs_unexport(chip);
343
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100344out:
345 mutex_unlock(&pwm_lock);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100346 return ret;
347}
348EXPORT_SYMBOL_GPL(pwmchip_remove);
349
350/**
351 * pwm_request() - request a PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200352 * @pwm: global PWM device index
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100353 * @label: PWM device label
Thierry Reding8138d2d2012-03-26 08:42:48 +0200354 *
355 * This function is deprecated, use pwm_get() instead.
Thierry Reding04883802015-07-27 11:58:32 +0200356 *
357 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
358 * failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100359 */
Thierry Redingf051c462011-12-14 11:12:23 +0100360struct pwm_device *pwm_request(int pwm, const char *label)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100361{
Thierry Redingf051c462011-12-14 11:12:23 +0100362 struct pwm_device *dev;
363 int err;
364
365 if (pwm < 0 || pwm >= MAX_PWMS)
366 return ERR_PTR(-EINVAL);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100367
368 mutex_lock(&pwm_lock);
369
Thierry Redingf051c462011-12-14 11:12:23 +0100370 dev = pwm_to_device(pwm);
371 if (!dev) {
372 dev = ERR_PTR(-EPROBE_DEFER);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100373 goto out;
374 }
375
Thierry Redingf051c462011-12-14 11:12:23 +0100376 err = pwm_device_request(dev, label);
377 if (err < 0)
378 dev = ERR_PTR(err);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100379
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100380out:
381 mutex_unlock(&pwm_lock);
382
Thierry Redingf051c462011-12-14 11:12:23 +0100383 return dev;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100384}
385EXPORT_SYMBOL_GPL(pwm_request);
386
387/**
Thierry Redingf051c462011-12-14 11:12:23 +0100388 * 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 *
Thierry Reding04883802015-07-27 11:58:32 +0200393 * 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.
Thierry Redingf051c462011-12-14 11:12:23 +0100396 */
397struct 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;
403
404 if (!chip || index >= chip->npwm)
405 return ERR_PTR(-EINVAL);
406
407 mutex_lock(&pwm_lock);
408 pwm = &chip->pwms[index];
409
410 err = pwm_device_request(pwm, label);
411 if (err < 0)
412 pwm = ERR_PTR(err);
413
414 mutex_unlock(&pwm_lock);
415 return pwm;
416}
417EXPORT_SYMBOL_GPL(pwm_request_from_chip);
418
419/**
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100420 * pwm_free() - free a PWM device
421 * @pwm: PWM device
Thierry Reding8138d2d2012-03-26 08:42:48 +0200422 *
423 * This function is deprecated, use pwm_put() instead.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100424 */
425void pwm_free(struct pwm_device *pwm)
426{
Thierry Reding8138d2d2012-03-26 08:42:48 +0200427 pwm_put(pwm);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100428}
429EXPORT_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
Thierry Reding04883802015-07-27 11:58:32 +0200436 *
437 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100438 */
439int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
440{
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700441 int err;
442
Thierry Redingc2d476a2012-09-02 22:13:40 +0200443 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
Thierry Redingf051c462011-12-14 11:12:23 +0100444 return -EINVAL;
445
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700446 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;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100454}
455EXPORT_SYMBOL_GPL(pwm_config);
456
457/**
Philip, Avinash0aa08692012-07-24 19:35:32 +0530458 * pwm_set_polarity() - configure the polarity of a PWM signal
459 * @pwm: PWM device
460 * @polarity: new polarity of the PWM signal
461 *
Thierry Reding04883802015-07-27 11:58:32 +0200462 * 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.
Philip, Avinash0aa08692012-07-24 19:35:32 +0530466 */
467int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
468{
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700469 int err;
470
Philip, Avinash0aa08692012-07-24 19:35:32 +0530471 if (!pwm || !pwm->chip->ops)
472 return -EINVAL;
473
474 if (!pwm->chip->ops->set_polarity)
475 return -ENOSYS;
476
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700477 mutex_lock(&pwm->lock);
478
479 if (pwm_is_enabled(pwm)) {
480 err = -EBUSY;
481 goto unlock;
482 }
Philip, Avinash0aa08692012-07-24 19:35:32 +0530483
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700484 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
485 if (err)
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700486 goto unlock;
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700487
488 pwm->polarity = polarity;
489
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700490unlock:
491 mutex_unlock(&pwm->lock);
492 return err;
Philip, Avinash0aa08692012-07-24 19:35:32 +0530493}
494EXPORT_SYMBOL_GPL(pwm_set_polarity);
495
496/**
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100497 * pwm_enable() - start a PWM output toggling
498 * @pwm: PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200499 *
500 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100501 */
502int pwm_enable(struct pwm_device *pwm)
503{
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700504 int err = 0;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100505
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700506 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);
518
519 return err;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100520}
521EXPORT_SYMBOL_GPL(pwm_enable);
522
523/**
524 * pwm_disable() - stop a PWM output toggling
525 * @pwm: PWM device
526 */
527void pwm_disable(struct pwm_device *pwm)
528{
Thierry Redingf051c462011-12-14 11:12:23 +0100529 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
530 pwm->chip->ops->disable(pwm->chip, pwm);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100531}
532EXPORT_SYMBOL_GPL(pwm_disable);
Thierry Reding62099ab2012-03-26 09:31:48 +0200533
Thierry Reding7299ab72011-12-14 11:10:32 +0100534static 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/**
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800552 * of_pwm_get() - request a PWM via the PWM framework
Thierry Reding7299ab72011-12-14 11:10:32 +0100553 * @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.
Thierry Reding04883802015-07-27 11:58:32 +0200566 *
567 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
568 * error code on failure.
Thierry Reding7299ab72011-12-14 11:10:32 +0100569 */
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800570struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
Thierry Reding7299ab72011-12-14 11:10:32 +0100571{
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
623put:
624 of_node_put(args.np);
625
626 return pwm;
627}
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800628EXPORT_SYMBOL_GPL(of_pwm_get);
Thierry Reding7299ab72011-12-14 11:10:32 +0100629
Thierry Reding8138d2d2012-03-26 08:42:48 +0200630/**
631 * pwm_add_table() - register PWM device consumers
632 * @table: array of consumers to register
633 * @num: number of consumers in table
634 */
Shobhit Kumarc264f112015-03-12 22:01:31 +0530635void pwm_add_table(struct pwm_lookup *table, size_t num)
Thierry Reding8138d2d2012-03-26 08:42:48 +0200636{
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
647/**
Shobhit Kumarefb0de52015-05-05 15:04:18 +0530648 * pwm_remove_table() - unregister PWM device consumers
649 * @table: array of consumers to unregister
650 * @num: number of consumers in table
651 */
652void 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
664/**
Thierry Reding8138d2d2012-03-26 08:42:48 +0200665 * pwm_get() - look up and request a PWM device
666 * @dev: device for PWM consumer
667 * @con_id: consumer name
668 *
Thierry Reding7299ab72011-12-14 11:10:32 +0100669 * 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()).
Thierry Reding8138d2d2012-03-26 08:42:48 +0200672 *
673 * Once a PWM chip has been found the specified PWM device will be requested
674 * and is ready to be used.
Thierry Reding04883802015-07-27 11:58:32 +0200675 *
676 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
677 * error code on failure.
Thierry Reding8138d2d2012-03-26 08:42:48 +0200678 */
679struct pwm_device *pwm_get(struct device *dev, const char *con_id)
680{
681 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
Sachin Kamate50d3522012-08-10 16:41:13 +0530682 const char *dev_id = dev ? dev_name(dev) : NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200683 struct pwm_chip *chip = NULL;
684 unsigned int best = 0;
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200685 struct pwm_lookup *p, *chosen = NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200686 unsigned int match;
687
Thierry Reding7299ab72011-12-14 11:10:32 +0100688 /* look up via DT first */
689 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800690 return of_pwm_get(dev->of_node, con_id);
Thierry Reding7299ab72011-12-14 11:10:32 +0100691
Thierry Reding8138d2d2012-03-26 08:42:48 +0200692 /*
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) {
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200732 chosen = p;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200733
734 if (match != 3)
735 best = match;
736 else
737 break;
738 }
739 }
740
Thierry Reding655a0352015-10-05 14:38:32 +0200741 if (!chosen) {
742 pwm = ERR_PTR(-ENODEV);
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200743 goto out;
Thierry Reding655a0352015-10-05 14:38:32 +0200744 }
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200745
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200746 chip = pwmchip_find_by_name(chosen->provider);
747 if (!chip)
748 goto out;
749
750 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200751 if (IS_ERR(pwm))
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200752 goto out;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200753
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200754 pwm_set_period(pwm, chosen->period);
755 pwm_set_polarity(pwm, chosen->polarity);
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200756
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200757out:
758 mutex_unlock(&pwm_lookup_lock);
Thierry Reding8138d2d2012-03-26 08:42:48 +0200759 return pwm;
760}
761EXPORT_SYMBOL_GPL(pwm_get);
762
763/**
764 * pwm_put() - release a PWM device
765 * @pwm: PWM device
766 */
767void pwm_put(struct pwm_device *pwm)
768{
769 if (!pwm)
770 return;
771
772 mutex_lock(&pwm_lock);
773
774 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
Sachin Kamate50d3522012-08-10 16:41:13 +0530775 pr_warn("PWM device already freed\n");
Thierry Reding8138d2d2012-03-26 08:42:48 +0200776 goto out;
777 }
778
779 if (pwm->chip->ops->free)
780 pwm->chip->ops->free(pwm->chip, pwm);
781
782 pwm->label = NULL;
783
784 module_put(pwm->chip->ops->owner);
785out:
786 mutex_unlock(&pwm_lock);
787}
788EXPORT_SYMBOL_GPL(pwm_put);
789
Alexandre Courbot63543162012-08-01 19:20:58 +0900790static void devm_pwm_release(struct device *dev, void *res)
791{
792 pwm_put(*(struct pwm_device **)res);
793}
794
795/**
796 * devm_pwm_get() - resource managed pwm_get()
797 * @dev: device for PWM consumer
798 * @con_id: consumer name
799 *
800 * This function performs like pwm_get() but the acquired PWM device will
801 * automatically be released on driver detach.
Thierry Reding04883802015-07-27 11:58:32 +0200802 *
803 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
804 * error code on failure.
Alexandre Courbot63543162012-08-01 19:20:58 +0900805 */
806struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
807{
808 struct pwm_device **ptr, *pwm;
809
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200810 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Alexandre Courbot63543162012-08-01 19:20:58 +0900811 if (!ptr)
812 return ERR_PTR(-ENOMEM);
813
814 pwm = pwm_get(dev, con_id);
815 if (!IS_ERR(pwm)) {
816 *ptr = pwm;
817 devres_add(dev, ptr);
818 } else {
819 devres_free(ptr);
820 }
821
822 return pwm;
823}
824EXPORT_SYMBOL_GPL(devm_pwm_get);
825
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800826/**
827 * devm_of_pwm_get() - resource managed of_pwm_get()
828 * @dev: device for PWM consumer
829 * @np: device node to get the PWM from
830 * @con_id: consumer name
831 *
832 * This function performs like of_pwm_get() but the acquired PWM device will
833 * automatically be released on driver detach.
Thierry Reding04883802015-07-27 11:58:32 +0200834 *
835 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
836 * error code on failure.
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800837 */
838struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
839 const char *con_id)
840{
841 struct pwm_device **ptr, *pwm;
842
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200843 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800844 if (!ptr)
845 return ERR_PTR(-ENOMEM);
846
847 pwm = of_pwm_get(np, con_id);
848 if (!IS_ERR(pwm)) {
849 *ptr = pwm;
850 devres_add(dev, ptr);
851 } else {
852 devres_free(ptr);
853 }
854
855 return pwm;
856}
857EXPORT_SYMBOL_GPL(devm_of_pwm_get);
858
Alexandre Courbot63543162012-08-01 19:20:58 +0900859static int devm_pwm_match(struct device *dev, void *res, void *data)
860{
861 struct pwm_device **p = res;
862
863 if (WARN_ON(!p || !*p))
864 return 0;
865
866 return *p == data;
867}
868
869/**
870 * devm_pwm_put() - resource managed pwm_put()
871 * @dev: device for PWM consumer
872 * @pwm: PWM device
873 *
874 * Release a PWM previously allocated using devm_pwm_get(). Calling this
875 * function is usually not needed because devm-allocated resources are
876 * automatically released on driver detach.
877 */
878void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
879{
880 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
881}
882EXPORT_SYMBOL_GPL(devm_pwm_put);
883
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100884/**
885 * pwm_can_sleep() - report whether PWM access will sleep
886 * @pwm: PWM device
887 *
Thierry Reding04883802015-07-27 11:58:32 +0200888 * Returns: True if accessing the PWM can sleep, false otherwise.
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100889 */
890bool pwm_can_sleep(struct pwm_device *pwm)
891{
Thierry Redingff01c942016-01-21 15:04:59 +0100892 return true;
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100893}
894EXPORT_SYMBOL_GPL(pwm_can_sleep);
895
Thierry Reding62099ab2012-03-26 09:31:48 +0200896#ifdef CONFIG_DEBUG_FS
897static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
898{
899 unsigned int i;
900
901 for (i = 0; i < chip->npwm; i++) {
902 struct pwm_device *pwm = &chip->pwms[i];
903
904 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
905
906 if (test_bit(PWMF_REQUESTED, &pwm->flags))
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900907 seq_puts(s, " requested");
Thierry Reding62099ab2012-03-26 09:31:48 +0200908
Boris Brezillon5c312522015-07-01 10:21:47 +0200909 if (pwm_is_enabled(pwm))
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900910 seq_puts(s, " enabled");
Thierry Reding62099ab2012-03-26 09:31:48 +0200911
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900912 seq_puts(s, "\n");
Thierry Reding62099ab2012-03-26 09:31:48 +0200913 }
914}
915
916static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
917{
918 mutex_lock(&pwm_lock);
919 s->private = "";
920
921 return seq_list_start(&pwm_chips, *pos);
922}
923
924static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
925{
926 s->private = "\n";
927
928 return seq_list_next(v, &pwm_chips, pos);
929}
930
931static void pwm_seq_stop(struct seq_file *s, void *v)
932{
933 mutex_unlock(&pwm_lock);
934}
935
936static int pwm_seq_show(struct seq_file *s, void *v)
937{
938 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
939
940 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
941 chip->dev->bus ? chip->dev->bus->name : "no-bus",
942 dev_name(chip->dev), chip->npwm,
943 (chip->npwm != 1) ? "s" : "");
944
945 if (chip->ops->dbg_show)
946 chip->ops->dbg_show(chip, s);
947 else
948 pwm_dbg_show(chip, s);
949
950 return 0;
951}
952
953static const struct seq_operations pwm_seq_ops = {
954 .start = pwm_seq_start,
955 .next = pwm_seq_next,
956 .stop = pwm_seq_stop,
957 .show = pwm_seq_show,
958};
959
960static int pwm_seq_open(struct inode *inode, struct file *file)
961{
962 return seq_open(file, &pwm_seq_ops);
963}
964
965static const struct file_operations pwm_debugfs_ops = {
966 .owner = THIS_MODULE,
967 .open = pwm_seq_open,
968 .read = seq_read,
969 .llseek = seq_lseek,
970 .release = seq_release,
971};
972
973static int __init pwm_debugfs_init(void)
974{
975 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
976 &pwm_debugfs_ops);
977
978 return 0;
979}
Thierry Reding62099ab2012-03-26 09:31:48 +0200980subsys_initcall(pwm_debugfs_init);
981#endif /* CONFIG_DEBUG_FS */