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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];
Thierry Reding83a98862016-05-02 12:05:55 +020078
Thierry Redingf051c462011-12-14 11:12:23 +010079 radix_tree_delete(&pwm_tree, pwm->pwm);
Sascha Hauer0c2498f2011-01-28 09:40:40 +010080 }
81
Thierry Redingf051c462011-12-14 11:12:23 +010082 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
83
84 kfree(chip->pwms);
85 chip->pwms = NULL;
86}
87
Thierry Reding8138d2d2012-03-26 08:42:48 +020088static 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
Thierry Redingf051c462011-12-14 11:12:23 +0100111static 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
Philip, Avinash83af2402012-11-21 13:10:44 +0530135struct pwm_device *
136of_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
Boris Brezillone39c0df2016-04-14 21:17:21 +0200150 pwm->args.period = args->args[1];
Philip, Avinash83af2402012-11-21 13:10:44 +0530151
Laurent Pinchart208be762013-07-18 00:54:22 +0200152 if (args->args[2] & PWM_POLARITY_INVERTED)
Boris Brezillone39c0df2016-04-14 21:17:21 +0200153 pwm->args.polarity = PWM_POLARITY_INVERSED;
Philip, Avinash83af2402012-11-21 13:10:44 +0530154 else
Boris Brezillone39c0df2016-04-14 21:17:21 +0200155 pwm->args.polarity = PWM_POLARITY_NORMAL;
Philip, Avinash83af2402012-11-21 13:10:44 +0530156
157 return pwm;
158}
Thierry Reding417328c2012-11-28 15:12:07 +0100159EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
Philip, Avinash83af2402012-11-21 13:10:44 +0530160
Sachin Kamate50d3522012-08-10 16:41:13 +0530161static struct pwm_device *
162of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
Thierry Reding7299ab72011-12-14 11:10:32 +0100163{
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
Boris Brezillone39c0df2016-04-14 21:17:21 +0200176 pwm->args.period = args->args[1];
Thierry Reding7299ab72011-12-14 11:10:32 +0100177
178 return pwm;
179}
180
Sachin Kamatdfeb86e2012-08-02 12:32:42 +0530181static void of_pwmchip_add(struct pwm_chip *chip)
Thierry Reding7299ab72011-12-14 11:10:32 +0100182{
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
Sachin Kamatdfeb86e2012-08-02 12:32:42 +0530194static void of_pwmchip_remove(struct pwm_chip *chip)
Thierry Reding7299ab72011-12-14 11:10:32 +0100195{
Markus Elfring8d6cc072015-02-03 11:54:28 +0100196 if (chip->dev)
Thierry Reding7299ab72011-12-14 11:10:32 +0100197 of_node_put(chip->dev->of_node);
198}
199
Thierry Redingf051c462011-12-14 11:12:23 +0100200/**
201 * pwm_set_chip_data() - set private chip data for a PWM
202 * @pwm: PWM device
203 * @data: pointer to chip-specific data
Thierry Reding04883802015-07-27 11:58:32 +0200204 *
205 * Returns: 0 on success or a negative error code on failure.
Thierry Redingf051c462011-12-14 11:12:23 +0100206 */
207int 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}
Thierry Reding928c4472013-01-30 09:22:24 +0100216EXPORT_SYMBOL_GPL(pwm_set_chip_data);
Thierry Redingf051c462011-12-14 11:12:23 +0100217
218/**
219 * pwm_get_chip_data() - get private chip data for a PWM
220 * @pwm: PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200221 *
222 * Returns: A pointer to the chip-private data for the PWM device.
Thierry Redingf051c462011-12-14 11:12:23 +0100223 */
224void *pwm_get_chip_data(struct pwm_device *pwm)
225{
226 return pwm ? pwm->chip_data : NULL;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100227}
Thierry Reding928c4472013-01-30 09:22:24 +0100228EXPORT_SYMBOL_GPL(pwm_get_chip_data);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100229
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200230static 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
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100243/**
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700244 * pwmchip_add_with_polarity() - register a new PWM chip
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100245 * @chip: the PWM chip to add
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700246 * @polarity: initial polarity of PWM channels
Thierry Redingf051c462011-12-14 11:12:23 +0100247 *
248 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700249 * will be used. The initial polarity for all channels is specified by the
250 * @polarity parameter.
Thierry Reding04883802015-07-27 11:58:32 +0200251 *
252 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100253 */
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700254int pwmchip_add_with_polarity(struct pwm_chip *chip,
255 enum pwm_polarity polarity)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100256{
257 struct pwm_device *pwm;
Thierry Redingf051c462011-12-14 11:12:23 +0100258 unsigned int i;
259 int ret;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100260
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200261 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
262 return -EINVAL;
263
264 if (!pwm_ops_check(chip->ops))
Thierry Redingf051c462011-12-14 11:12:23 +0100265 return -EINVAL;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100266
267 mutex_lock(&pwm_lock);
268
Thierry Redingf051c462011-12-14 11:12:23 +0100269 ret = alloc_pwms(chip->base, chip->npwm);
270 if (ret < 0)
271 goto out;
272
Thierry Reding2907f8a2016-05-02 12:07:34 +0200273 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
Thierry Redingf051c462011-12-14 11:12:23 +0100274 if (!chip->pwms) {
275 ret = -ENOMEM;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100276 goto out;
277 }
278
Thierry Redingf051c462011-12-14 11:12:23 +0100279 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;
Boris Brezillon43a276b2016-04-14 21:17:38 +0200287 pwm->state.polarity = polarity;
Thierry Redingf051c462011-12-14 11:12:23 +0100288
Boris Brezillon15fa8a432016-04-14 21:17:40 +0200289 if (chip->ops->get_state)
290 chip->ops->get_state(chip, pwm, &pwm->state);
Thierry Redingf051c462011-12-14 11:12:23 +0100291
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);
299
300 ret = 0;
301
Thierry Reding7299ab72011-12-14 11:10:32 +0100302 if (IS_ENABLED(CONFIG_OF))
303 of_pwmchip_add(chip);
304
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700305 pwmchip_sysfs_export(chip);
306
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100307out:
308 mutex_unlock(&pwm_lock);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100309 return ret;
310}
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700311EXPORT_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.
Thierry Reding04883802015-07-27 11:58:32 +0200319 *
320 * Returns: 0 on success or a negative error code on failure.
Tim Krygerb6a00fa2015-05-26 13:08:16 -0700321 */
322int pwmchip_add(struct pwm_chip *chip)
323{
324 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
325}
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100326EXPORT_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.
Thierry Reding04883802015-07-27 11:58:32 +0200334 *
335 * Returns: 0 on success or a negative error code on failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100336 */
337int pwmchip_remove(struct pwm_chip *chip)
338{
Thierry Redingf051c462011-12-14 11:12:23 +0100339 unsigned int i;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100340 int ret = 0;
341
342 mutex_lock(&pwm_lock);
343
Thierry Redingf051c462011-12-14 11:12:23 +0100344 for (i = 0; i < chip->npwm; i++) {
345 struct pwm_device *pwm = &chip->pwms[i];
346
347 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
348 ret = -EBUSY;
349 goto out;
350 }
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100351 }
352
Thierry Redingf051c462011-12-14 11:12:23 +0100353 list_del_init(&chip->list);
Thierry Reding7299ab72011-12-14 11:10:32 +0100354
355 if (IS_ENABLED(CONFIG_OF))
356 of_pwmchip_remove(chip);
357
Thierry Redingf051c462011-12-14 11:12:23 +0100358 free_pwms(chip);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100359
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700360 pwmchip_sysfs_unexport(chip);
361
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100362out:
363 mutex_unlock(&pwm_lock);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100364 return ret;
365}
366EXPORT_SYMBOL_GPL(pwmchip_remove);
367
368/**
369 * pwm_request() - request a PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200370 * @pwm: global PWM device index
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100371 * @label: PWM device label
Thierry Reding8138d2d2012-03-26 08:42:48 +0200372 *
373 * This function is deprecated, use pwm_get() instead.
Thierry Reding04883802015-07-27 11:58:32 +0200374 *
375 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
376 * failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100377 */
Thierry Redingf051c462011-12-14 11:12:23 +0100378struct pwm_device *pwm_request(int pwm, const char *label)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100379{
Thierry Redingf051c462011-12-14 11:12:23 +0100380 struct pwm_device *dev;
381 int err;
382
383 if (pwm < 0 || pwm >= MAX_PWMS)
384 return ERR_PTR(-EINVAL);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100385
386 mutex_lock(&pwm_lock);
387
Thierry Redingf051c462011-12-14 11:12:23 +0100388 dev = pwm_to_device(pwm);
389 if (!dev) {
390 dev = ERR_PTR(-EPROBE_DEFER);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100391 goto out;
392 }
393
Thierry Redingf051c462011-12-14 11:12:23 +0100394 err = pwm_device_request(dev, label);
395 if (err < 0)
396 dev = ERR_PTR(err);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100397
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100398out:
399 mutex_unlock(&pwm_lock);
400
Thierry Redingf051c462011-12-14 11:12:23 +0100401 return dev;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100402}
403EXPORT_SYMBOL_GPL(pwm_request);
404
405/**
Thierry Redingf051c462011-12-14 11:12:23 +0100406 * 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 *
Thierry Reding04883802015-07-27 11:58:32 +0200411 * 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.
Thierry Redingf051c462011-12-14 11:12:23 +0100414 */
415struct 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;
421
422 if (!chip || index >= chip->npwm)
423 return ERR_PTR(-EINVAL);
424
425 mutex_lock(&pwm_lock);
426 pwm = &chip->pwms[index];
427
428 err = pwm_device_request(pwm, label);
429 if (err < 0)
430 pwm = ERR_PTR(err);
431
432 mutex_unlock(&pwm_lock);
433 return pwm;
434}
435EXPORT_SYMBOL_GPL(pwm_request_from_chip);
436
437/**
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100438 * pwm_free() - free a PWM device
439 * @pwm: PWM device
Thierry Reding8138d2d2012-03-26 08:42:48 +0200440 *
441 * This function is deprecated, use pwm_put() instead.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100442 */
443void pwm_free(struct pwm_device *pwm)
444{
Thierry Reding8138d2d2012-03-26 08:42:48 +0200445 pwm_put(pwm);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100446}
447EXPORT_SYMBOL_GPL(pwm_free);
448
449/**
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200450 * pwm_apply_state() - atomically apply a new state to a PWM device
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100451 * @pwm: PWM device
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200452 * @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.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100455 */
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200456int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100457{
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700458 int err;
459
Brian Norrisef2bf492016-05-27 09:45:49 -0700460 if (!pwm || !state || !state->period ||
461 state->duty_cycle > state->period)
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700462 return -EINVAL;
463
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200464 if (!memcmp(state, &pwm->state, sizeof(*state)))
465 return 0;
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700466
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200467 if (pwm->chip->ops->apply) {
468 err = pwm->chip->ops->apply(pwm->chip, pwm, state);
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700469 if (err)
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200470 return err;
471
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 }
498
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;
506
507 pwm->state.duty_cycle = state->duty_cycle;
508 pwm->state.period = state->period;
509 }
510
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 }
519
520 pwm->state.enabled = state->enabled;
521 }
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700522 }
523
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200524 return 0;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100525}
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200526EXPORT_SYMBOL_GPL(pwm_apply_state);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100527
528/**
Lee Jones3a3d1a42016-06-08 10:21:23 +0100529 * 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 */
536int 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}
553EXPORT_SYMBOL_GPL(pwm_capture);
554
555/**
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200556 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100557 * @pwm: PWM device
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200558 *
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.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100562 */
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200563int pwm_adjust_config(struct pwm_device *pwm)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100564{
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200565 struct pwm_state state;
566 struct pwm_args pargs;
Boris Brezillon09a7e4a2016-04-14 21:17:39 +0200567
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200568 pwm_get_args(pwm, &pargs);
569 pwm_get_state(pwm, &state);
570
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;
583
584 return pwm_apply_state(pwm, &state);
Boris Brezillon09a7e4a2016-04-14 21:17:39 +0200585 }
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200586
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;
593
594 do_div(dutycycle, state.period);
595 state.duty_cycle = dutycycle;
596 state.period = pargs.period;
597 }
598
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;
605 }
606
607 return pwm_apply_state(pwm, &state);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100608}
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200609EXPORT_SYMBOL_GPL(pwm_adjust_config);
Thierry Reding62099ab2012-03-26 09:31:48 +0200610
Thierry Reding7299ab72011-12-14 11:10:32 +0100611static 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/**
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800629 * of_pwm_get() - request a PWM via the PWM framework
Thierry Reding7299ab72011-12-14 11:10:32 +0100630 * @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.
Thierry Reding04883802015-07-27 11:58:32 +0200643 *
644 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
645 * error code on failure.
Thierry Reding7299ab72011-12-14 11:10:32 +0100646 */
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800647struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
Thierry Reding7299ab72011-12-14 11:10:32 +0100648{
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
700put:
701 of_node_put(args.np);
702
703 return pwm;
704}
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800705EXPORT_SYMBOL_GPL(of_pwm_get);
Thierry Reding7299ab72011-12-14 11:10:32 +0100706
Thierry Reding8138d2d2012-03-26 08:42:48 +0200707/**
708 * pwm_add_table() - register PWM device consumers
709 * @table: array of consumers to register
710 * @num: number of consumers in table
711 */
Shobhit Kumarc264f112015-03-12 22:01:31 +0530712void pwm_add_table(struct pwm_lookup *table, size_t num)
Thierry Reding8138d2d2012-03-26 08:42:48 +0200713{
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
724/**
Shobhit Kumarefb0de52015-05-05 15:04:18 +0530725 * pwm_remove_table() - unregister PWM device consumers
726 * @table: array of consumers to unregister
727 * @num: number of consumers in table
728 */
729void 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
741/**
Thierry Reding8138d2d2012-03-26 08:42:48 +0200742 * pwm_get() - look up and request a PWM device
743 * @dev: device for PWM consumer
744 * @con_id: consumer name
745 *
Thierry Reding7299ab72011-12-14 11:10:32 +0100746 * 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()).
Thierry Reding8138d2d2012-03-26 08:42:48 +0200749 *
750 * Once a PWM chip has been found the specified PWM device will be requested
751 * and is ready to be used.
Thierry Reding04883802015-07-27 11:58:32 +0200752 *
753 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
754 * error code on failure.
Thierry Reding8138d2d2012-03-26 08:42:48 +0200755 */
756struct pwm_device *pwm_get(struct device *dev, const char *con_id)
757{
758 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
Sachin Kamate50d3522012-08-10 16:41:13 +0530759 const char *dev_id = dev ? dev_name(dev) : NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200760 struct pwm_chip *chip = NULL;
761 unsigned int best = 0;
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200762 struct pwm_lookup *p, *chosen = NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200763 unsigned int match;
764
Thierry Reding7299ab72011-12-14 11:10:32 +0100765 /* look up via DT first */
766 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800767 return of_pwm_get(dev->of_node, con_id);
Thierry Reding7299ab72011-12-14 11:10:32 +0100768
Thierry Reding8138d2d2012-03-26 08:42:48 +0200769 /*
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) {
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200809 chosen = p;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200810
811 if (match != 3)
812 best = match;
813 else
814 break;
815 }
816 }
817
Thierry Reding655a0352015-10-05 14:38:32 +0200818 if (!chosen) {
819 pwm = ERR_PTR(-ENODEV);
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200820 goto out;
Thierry Reding655a0352015-10-05 14:38:32 +0200821 }
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200822
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200823 chip = pwmchip_find_by_name(chosen->provider);
824 if (!chip)
825 goto out;
826
827 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200828 if (IS_ERR(pwm))
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200829 goto out;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200830
Boris Brezillonfbd45a12016-05-17 14:27:25 +0200831 pwm->args.period = chosen->period;
832 pwm->args.polarity = chosen->polarity;
833
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200834out:
835 mutex_unlock(&pwm_lookup_lock);
Thierry Reding8138d2d2012-03-26 08:42:48 +0200836 return pwm;
837}
838EXPORT_SYMBOL_GPL(pwm_get);
839
840/**
841 * pwm_put() - release a PWM device
842 * @pwm: PWM device
843 */
844void 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)) {
Sachin Kamate50d3522012-08-10 16:41:13 +0530852 pr_warn("PWM device already freed\n");
Thierry Reding8138d2d2012-03-26 08:42:48 +0200853 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);
862out:
863 mutex_unlock(&pwm_lock);
864}
865EXPORT_SYMBOL_GPL(pwm_put);
866
Alexandre Courbot63543162012-08-01 19:20:58 +0900867static 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.
Thierry Reding04883802015-07-27 11:58:32 +0200879 *
880 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
881 * error code on failure.
Alexandre Courbot63543162012-08-01 19:20:58 +0900882 */
883struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
884{
885 struct pwm_device **ptr, *pwm;
886
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200887 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Alexandre Courbot63543162012-08-01 19:20:58 +0900888 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}
901EXPORT_SYMBOL_GPL(devm_pwm_get);
902
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800903/**
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.
Thierry Reding04883802015-07-27 11:58:32 +0200911 *
912 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
913 * error code on failure.
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800914 */
915struct 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
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200920 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800921 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}
934EXPORT_SYMBOL_GPL(devm_of_pwm_get);
935
Alexandre Courbot63543162012-08-01 19:20:58 +0900936static 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 */
955void 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}
959EXPORT_SYMBOL_GPL(devm_pwm_put);
960
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100961/**
962 * pwm_can_sleep() - report whether PWM access will sleep
963 * @pwm: PWM device
964 *
Thierry Reding04883802015-07-27 11:58:32 +0200965 * Returns: True if accessing the PWM can sleep, false otherwise.
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100966 */
967bool pwm_can_sleep(struct pwm_device *pwm)
968{
Thierry Redingff01c942016-01-21 15:04:59 +0100969 return true;
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100970}
971EXPORT_SYMBOL_GPL(pwm_can_sleep);
972
Thierry Reding62099ab2012-03-26 09:31:48 +0200973#ifdef CONFIG_DEBUG_FS
974static 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];
Boris Brezillon39100ce2016-04-14 21:17:43 +0200980 struct pwm_state state;
981
982 pwm_get_state(pwm, &state);
Thierry Reding62099ab2012-03-26 09:31:48 +0200983
984 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
985
986 if (test_bit(PWMF_REQUESTED, &pwm->flags))
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900987 seq_puts(s, " requested");
Thierry Reding62099ab2012-03-26 09:31:48 +0200988
Boris Brezillon39100ce2016-04-14 21:17:43 +0200989 if (state.enabled)
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900990 seq_puts(s, " enabled");
Thierry Reding62099ab2012-03-26 09:31:48 +0200991
Heiko Stübner23e35232016-04-14 21:17:44 +0200992 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
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900997 seq_puts(s, "\n");
Thierry Reding62099ab2012-03-26 09:31:48 +0200998 }
999}
1000
1001static 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
1009static 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
1016static void pwm_seq_stop(struct seq_file *s, void *v)
1017{
1018 mutex_unlock(&pwm_lock);
1019}
1020
1021static 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
1038static 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
1045static int pwm_seq_open(struct inode *inode, struct file *file)
1046{
1047 return seq_open(file, &pwm_seq_ops);
1048}
1049
1050static 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
1058static 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}
Thierry Reding62099ab2012-03-26 09:31:48 +02001065subsys_initcall(pwm_debugfs_init);
1066#endif /* CONFIG_DEBUG_FS */