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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
David Hsu07334242016-08-09 14:57:46 -0700342 pwmchip_sysfs_unexport_children(chip);
343
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100344 mutex_lock(&pwm_lock);
345
Thierry Redingf051c462011-12-14 11:12:23 +0100346 for (i = 0; i < chip->npwm; i++) {
347 struct pwm_device *pwm = &chip->pwms[i];
348
349 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
350 ret = -EBUSY;
351 goto out;
352 }
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100353 }
354
Thierry Redingf051c462011-12-14 11:12:23 +0100355 list_del_init(&chip->list);
Thierry Reding7299ab72011-12-14 11:10:32 +0100356
357 if (IS_ENABLED(CONFIG_OF))
358 of_pwmchip_remove(chip);
359
Thierry Redingf051c462011-12-14 11:12:23 +0100360 free_pwms(chip);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100361
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700362 pwmchip_sysfs_unexport(chip);
363
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100364out:
365 mutex_unlock(&pwm_lock);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100366 return ret;
367}
368EXPORT_SYMBOL_GPL(pwmchip_remove);
369
370/**
371 * pwm_request() - request a PWM device
Thierry Reding04883802015-07-27 11:58:32 +0200372 * @pwm: global PWM device index
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100373 * @label: PWM device label
Thierry Reding8138d2d2012-03-26 08:42:48 +0200374 *
375 * This function is deprecated, use pwm_get() instead.
Thierry Reding04883802015-07-27 11:58:32 +0200376 *
377 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
378 * failure.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100379 */
Thierry Redingf051c462011-12-14 11:12:23 +0100380struct pwm_device *pwm_request(int pwm, const char *label)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100381{
Thierry Redingf051c462011-12-14 11:12:23 +0100382 struct pwm_device *dev;
383 int err;
384
385 if (pwm < 0 || pwm >= MAX_PWMS)
386 return ERR_PTR(-EINVAL);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100387
388 mutex_lock(&pwm_lock);
389
Thierry Redingf051c462011-12-14 11:12:23 +0100390 dev = pwm_to_device(pwm);
391 if (!dev) {
392 dev = ERR_PTR(-EPROBE_DEFER);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100393 goto out;
394 }
395
Thierry Redingf051c462011-12-14 11:12:23 +0100396 err = pwm_device_request(dev, label);
397 if (err < 0)
398 dev = ERR_PTR(err);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100399
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100400out:
401 mutex_unlock(&pwm_lock);
402
Thierry Redingf051c462011-12-14 11:12:23 +0100403 return dev;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100404}
405EXPORT_SYMBOL_GPL(pwm_request);
406
407/**
Thierry Redingf051c462011-12-14 11:12:23 +0100408 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
409 * @chip: PWM chip
410 * @index: per-chip index of the PWM to request
411 * @label: a literal description string of this PWM
412 *
Thierry Reding04883802015-07-27 11:58:32 +0200413 * Returns: A pointer to the PWM device at the given index of the given PWM
414 * chip. A negative error code is returned if the index is not valid for the
415 * specified PWM chip or if the PWM device cannot be requested.
Thierry Redingf051c462011-12-14 11:12:23 +0100416 */
417struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
418 unsigned int index,
419 const char *label)
420{
421 struct pwm_device *pwm;
422 int err;
423
424 if (!chip || index >= chip->npwm)
425 return ERR_PTR(-EINVAL);
426
427 mutex_lock(&pwm_lock);
428 pwm = &chip->pwms[index];
429
430 err = pwm_device_request(pwm, label);
431 if (err < 0)
432 pwm = ERR_PTR(err);
433
434 mutex_unlock(&pwm_lock);
435 return pwm;
436}
437EXPORT_SYMBOL_GPL(pwm_request_from_chip);
438
439/**
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100440 * pwm_free() - free a PWM device
441 * @pwm: PWM device
Thierry Reding8138d2d2012-03-26 08:42:48 +0200442 *
443 * This function is deprecated, use pwm_put() instead.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100444 */
445void pwm_free(struct pwm_device *pwm)
446{
Thierry Reding8138d2d2012-03-26 08:42:48 +0200447 pwm_put(pwm);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100448}
449EXPORT_SYMBOL_GPL(pwm_free);
450
451/**
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200452 * pwm_apply_state() - atomically apply a new state to a PWM device
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100453 * @pwm: PWM device
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200454 * @state: new state to apply. This can be adjusted by the PWM driver
455 * if the requested config is not achievable, for example,
456 * ->duty_cycle and ->period might be approximated.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100457 */
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200458int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100459{
H Hartley Sweeten76abbdde2013-06-11 10:38:59 -0700460 int err;
461
Brian Norrisef2bf492016-05-27 09:45:49 -0700462 if (!pwm || !state || !state->period ||
463 state->duty_cycle > state->period)
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700464 return -EINVAL;
465
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200466 if (!memcmp(state, &pwm->state, sizeof(*state)))
467 return 0;
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700468
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200469 if (pwm->chip->ops->apply) {
470 err = pwm->chip->ops->apply(pwm->chip, pwm, state);
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700471 if (err)
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200472 return err;
473
474 pwm->state = *state;
475 } else {
476 /*
477 * FIXME: restore the initial state in case of error.
478 */
479 if (state->polarity != pwm->state.polarity) {
480 if (!pwm->chip->ops->set_polarity)
481 return -ENOTSUPP;
482
483 /*
484 * Changing the polarity of a running PWM is
485 * only allowed when the PWM driver implements
486 * ->apply().
487 */
488 if (pwm->state.enabled) {
489 pwm->chip->ops->disable(pwm->chip, pwm);
490 pwm->state.enabled = false;
491 }
492
493 err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
494 state->polarity);
495 if (err)
496 return err;
497
498 pwm->state.polarity = state->polarity;
499 }
500
501 if (state->period != pwm->state.period ||
502 state->duty_cycle != pwm->state.duty_cycle) {
503 err = pwm->chip->ops->config(pwm->chip, pwm,
504 state->duty_cycle,
505 state->period);
506 if (err)
507 return err;
508
509 pwm->state.duty_cycle = state->duty_cycle;
510 pwm->state.period = state->period;
511 }
512
513 if (state->enabled != pwm->state.enabled) {
514 if (state->enabled) {
515 err = pwm->chip->ops->enable(pwm->chip, pwm);
516 if (err)
517 return err;
518 } else {
519 pwm->chip->ops->disable(pwm->chip, pwm);
520 }
521
522 pwm->state.enabled = state->enabled;
523 }
Jonathan Richardsond1cd2142015-10-16 17:40:58 -0700524 }
525
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200526 return 0;
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100527}
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200528EXPORT_SYMBOL_GPL(pwm_apply_state);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100529
530/**
Lee Jones3a3d1a42016-06-08 10:21:23 +0100531 * pwm_capture() - capture and report a PWM signal
532 * @pwm: PWM device
533 * @result: structure to fill with capture result
534 * @timeout: time to wait, in milliseconds, before giving up on capture
535 *
536 * Returns: 0 on success or a negative error code on failure.
537 */
538int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
539 unsigned long timeout)
540{
541 int err;
542
543 if (!pwm || !pwm->chip->ops)
544 return -EINVAL;
545
546 if (!pwm->chip->ops->capture)
547 return -ENOSYS;
548
549 mutex_lock(&pwm_lock);
550 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
551 mutex_unlock(&pwm_lock);
552
553 return err;
554}
555EXPORT_SYMBOL_GPL(pwm_capture);
556
557/**
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200558 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100559 * @pwm: PWM device
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200560 *
561 * This function will adjust the PWM config to the PWM arguments provided
562 * by the DT or PWM lookup table. This is particularly useful to adapt
563 * the bootloader config to the Linux one.
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100564 */
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200565int pwm_adjust_config(struct pwm_device *pwm)
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100566{
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200567 struct pwm_state state;
568 struct pwm_args pargs;
Boris Brezillon09a7e4a2016-04-14 21:17:39 +0200569
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200570 pwm_get_args(pwm, &pargs);
571 pwm_get_state(pwm, &state);
572
573 /*
574 * If the current period is zero it means that either the PWM driver
575 * does not support initial state retrieval or the PWM has not yet
576 * been configured.
577 *
578 * In either case, we setup the new period and polarity, and assign a
579 * duty cycle of 0.
580 */
581 if (!state.period) {
582 state.duty_cycle = 0;
583 state.period = pargs.period;
584 state.polarity = pargs.polarity;
585
586 return pwm_apply_state(pwm, &state);
Boris Brezillon09a7e4a2016-04-14 21:17:39 +0200587 }
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200588
589 /*
590 * Adjust the PWM duty cycle/period based on the period value provided
591 * in PWM args.
592 */
593 if (pargs.period != state.period) {
594 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
595
596 do_div(dutycycle, state.period);
597 state.duty_cycle = dutycycle;
598 state.period = pargs.period;
599 }
600
601 /*
602 * If the polarity changed, we should also change the duty cycle.
603 */
604 if (pargs.polarity != state.polarity) {
605 state.polarity = pargs.polarity;
606 state.duty_cycle = state.period - state.duty_cycle;
607 }
608
609 return pwm_apply_state(pwm, &state);
Sascha Hauer0c2498f2011-01-28 09:40:40 +0100610}
Boris Brezillon5ec803e2016-04-14 21:17:41 +0200611EXPORT_SYMBOL_GPL(pwm_adjust_config);
Thierry Reding62099ab2012-03-26 09:31:48 +0200612
Thierry Reding7299ab72011-12-14 11:10:32 +0100613static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
614{
615 struct pwm_chip *chip;
616
617 mutex_lock(&pwm_lock);
618
619 list_for_each_entry(chip, &pwm_chips, list)
620 if (chip->dev && chip->dev->of_node == np) {
621 mutex_unlock(&pwm_lock);
622 return chip;
623 }
624
625 mutex_unlock(&pwm_lock);
626
627 return ERR_PTR(-EPROBE_DEFER);
628}
629
630/**
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800631 * of_pwm_get() - request a PWM via the PWM framework
Thierry Reding7299ab72011-12-14 11:10:32 +0100632 * @np: device node to get the PWM from
633 * @con_id: consumer name
634 *
635 * Returns the PWM device parsed from the phandle and index specified in the
636 * "pwms" property of a device tree node or a negative error-code on failure.
637 * Values parsed from the device tree are stored in the returned PWM device
638 * object.
639 *
640 * If con_id is NULL, the first PWM device listed in the "pwms" property will
641 * be requested. Otherwise the "pwm-names" property is used to do a reverse
642 * lookup of the PWM index. This also means that the "pwm-names" property
643 * becomes mandatory for devices that look up the PWM device via the con_id
644 * parameter.
Thierry Reding04883802015-07-27 11:58:32 +0200645 *
646 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
647 * error code on failure.
Thierry Reding7299ab72011-12-14 11:10:32 +0100648 */
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800649struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
Thierry Reding7299ab72011-12-14 11:10:32 +0100650{
651 struct pwm_device *pwm = NULL;
652 struct of_phandle_args args;
653 struct pwm_chip *pc;
654 int index = 0;
655 int err;
656
657 if (con_id) {
658 index = of_property_match_string(np, "pwm-names", con_id);
659 if (index < 0)
660 return ERR_PTR(index);
661 }
662
663 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
664 &args);
665 if (err) {
666 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
667 return ERR_PTR(err);
668 }
669
670 pc = of_node_to_pwmchip(args.np);
671 if (IS_ERR(pc)) {
672 pr_debug("%s(): PWM chip not found\n", __func__);
673 pwm = ERR_CAST(pc);
674 goto put;
675 }
676
677 if (args.args_count != pc->of_pwm_n_cells) {
678 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
679 args.np->full_name);
680 pwm = ERR_PTR(-EINVAL);
681 goto put;
682 }
683
684 pwm = pc->of_xlate(pc, &args);
685 if (IS_ERR(pwm))
686 goto put;
687
688 /*
689 * If a consumer name was not given, try to look it up from the
690 * "pwm-names" property if it exists. Otherwise use the name of
691 * the user device node.
692 */
693 if (!con_id) {
694 err = of_property_read_string_index(np, "pwm-names", index,
695 &con_id);
696 if (err < 0)
697 con_id = np->name;
698 }
699
700 pwm->label = con_id;
701
702put:
703 of_node_put(args.np);
704
705 return pwm;
706}
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800707EXPORT_SYMBOL_GPL(of_pwm_get);
Thierry Reding7299ab72011-12-14 11:10:32 +0100708
Thierry Reding8138d2d2012-03-26 08:42:48 +0200709/**
710 * pwm_add_table() - register PWM device consumers
711 * @table: array of consumers to register
712 * @num: number of consumers in table
713 */
Shobhit Kumarc264f112015-03-12 22:01:31 +0530714void pwm_add_table(struct pwm_lookup *table, size_t num)
Thierry Reding8138d2d2012-03-26 08:42:48 +0200715{
716 mutex_lock(&pwm_lookup_lock);
717
718 while (num--) {
719 list_add_tail(&table->list, &pwm_lookup_list);
720 table++;
721 }
722
723 mutex_unlock(&pwm_lookup_lock);
724}
725
726/**
Shobhit Kumarefb0de52015-05-05 15:04:18 +0530727 * pwm_remove_table() - unregister PWM device consumers
728 * @table: array of consumers to unregister
729 * @num: number of consumers in table
730 */
731void pwm_remove_table(struct pwm_lookup *table, size_t num)
732{
733 mutex_lock(&pwm_lookup_lock);
734
735 while (num--) {
736 list_del(&table->list);
737 table++;
738 }
739
740 mutex_unlock(&pwm_lookup_lock);
741}
742
743/**
Thierry Reding8138d2d2012-03-26 08:42:48 +0200744 * pwm_get() - look up and request a PWM device
745 * @dev: device for PWM consumer
746 * @con_id: consumer name
747 *
Thierry Reding7299ab72011-12-14 11:10:32 +0100748 * Lookup is first attempted using DT. If the device was not instantiated from
749 * a device tree, a PWM chip and a relative index is looked up via a table
750 * supplied by board setup code (see pwm_add_table()).
Thierry Reding8138d2d2012-03-26 08:42:48 +0200751 *
752 * Once a PWM chip has been found the specified PWM device will be requested
753 * and is ready to be used.
Thierry Reding04883802015-07-27 11:58:32 +0200754 *
755 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
756 * error code on failure.
Thierry Reding8138d2d2012-03-26 08:42:48 +0200757 */
758struct pwm_device *pwm_get(struct device *dev, const char *con_id)
759{
760 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
Sachin Kamate50d3522012-08-10 16:41:13 +0530761 const char *dev_id = dev ? dev_name(dev) : NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200762 struct pwm_chip *chip = NULL;
763 unsigned int best = 0;
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200764 struct pwm_lookup *p, *chosen = NULL;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200765 unsigned int match;
766
Thierry Reding7299ab72011-12-14 11:10:32 +0100767 /* look up via DT first */
768 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
Peter Ujfalusi8eb96122012-12-21 01:43:58 -0800769 return of_pwm_get(dev->of_node, con_id);
Thierry Reding7299ab72011-12-14 11:10:32 +0100770
Thierry Reding8138d2d2012-03-26 08:42:48 +0200771 /*
772 * We look up the provider in the static table typically provided by
773 * board setup code. We first try to lookup the consumer device by
774 * name. If the consumer device was passed in as NULL or if no match
775 * was found, we try to find the consumer by directly looking it up
776 * by name.
777 *
778 * If a match is found, the provider PWM chip is looked up by name
779 * and a PWM device is requested using the PWM device per-chip index.
780 *
781 * The lookup algorithm was shamelessly taken from the clock
782 * framework:
783 *
784 * We do slightly fuzzy matching here:
785 * An entry with a NULL ID is assumed to be a wildcard.
786 * If an entry has a device ID, it must match
787 * If an entry has a connection ID, it must match
788 * Then we take the most specific entry - with the following order
789 * of precedence: dev+con > dev only > con only.
790 */
791 mutex_lock(&pwm_lookup_lock);
792
793 list_for_each_entry(p, &pwm_lookup_list, list) {
794 match = 0;
795
796 if (p->dev_id) {
797 if (!dev_id || strcmp(p->dev_id, dev_id))
798 continue;
799
800 match += 2;
801 }
802
803 if (p->con_id) {
804 if (!con_id || strcmp(p->con_id, con_id))
805 continue;
806
807 match += 1;
808 }
809
810 if (match > best) {
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200811 chosen = p;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200812
813 if (match != 3)
814 best = match;
815 else
816 break;
817 }
818 }
819
Thierry Reding655a0352015-10-05 14:38:32 +0200820 if (!chosen) {
821 pwm = ERR_PTR(-ENODEV);
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200822 goto out;
Thierry Reding655a0352015-10-05 14:38:32 +0200823 }
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200824
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200825 chip = pwmchip_find_by_name(chosen->provider);
826 if (!chip)
827 goto out;
828
829 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
Alexandre Belloni3796ce12014-05-19 22:42:32 +0200830 if (IS_ERR(pwm))
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200831 goto out;
Thierry Reding8138d2d2012-03-26 08:42:48 +0200832
Boris Brezillonfbd45a12016-05-17 14:27:25 +0200833 pwm->args.period = chosen->period;
834 pwm->args.polarity = chosen->polarity;
835
Geert Uytterhoeven70145f82014-08-28 11:03:14 +0200836out:
837 mutex_unlock(&pwm_lookup_lock);
Thierry Reding8138d2d2012-03-26 08:42:48 +0200838 return pwm;
839}
840EXPORT_SYMBOL_GPL(pwm_get);
841
842/**
843 * pwm_put() - release a PWM device
844 * @pwm: PWM device
845 */
846void pwm_put(struct pwm_device *pwm)
847{
848 if (!pwm)
849 return;
850
851 mutex_lock(&pwm_lock);
852
853 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
Sachin Kamate50d3522012-08-10 16:41:13 +0530854 pr_warn("PWM device already freed\n");
Thierry Reding8138d2d2012-03-26 08:42:48 +0200855 goto out;
856 }
857
858 if (pwm->chip->ops->free)
859 pwm->chip->ops->free(pwm->chip, pwm);
860
861 pwm->label = NULL;
862
863 module_put(pwm->chip->ops->owner);
864out:
865 mutex_unlock(&pwm_lock);
866}
867EXPORT_SYMBOL_GPL(pwm_put);
868
Alexandre Courbot63543162012-08-01 19:20:58 +0900869static void devm_pwm_release(struct device *dev, void *res)
870{
871 pwm_put(*(struct pwm_device **)res);
872}
873
874/**
875 * devm_pwm_get() - resource managed pwm_get()
876 * @dev: device for PWM consumer
877 * @con_id: consumer name
878 *
879 * This function performs like pwm_get() but the acquired PWM device will
880 * automatically be released on driver detach.
Thierry Reding04883802015-07-27 11:58:32 +0200881 *
882 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
883 * error code on failure.
Alexandre Courbot63543162012-08-01 19:20:58 +0900884 */
885struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
886{
887 struct pwm_device **ptr, *pwm;
888
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200889 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Alexandre Courbot63543162012-08-01 19:20:58 +0900890 if (!ptr)
891 return ERR_PTR(-ENOMEM);
892
893 pwm = pwm_get(dev, con_id);
894 if (!IS_ERR(pwm)) {
895 *ptr = pwm;
896 devres_add(dev, ptr);
897 } else {
898 devres_free(ptr);
899 }
900
901 return pwm;
902}
903EXPORT_SYMBOL_GPL(devm_pwm_get);
904
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800905/**
906 * devm_of_pwm_get() - resource managed of_pwm_get()
907 * @dev: device for PWM consumer
908 * @np: device node to get the PWM from
909 * @con_id: consumer name
910 *
911 * This function performs like of_pwm_get() but the acquired PWM device will
912 * automatically be released on driver detach.
Thierry Reding04883802015-07-27 11:58:32 +0200913 *
914 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
915 * error code on failure.
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800916 */
917struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
918 const char *con_id)
919{
920 struct pwm_device **ptr, *pwm;
921
Wolfram Sang77f0b9d2013-06-03 22:27:17 +0200922 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
Peter Ujfalusi261a5ed2012-12-21 01:43:59 -0800923 if (!ptr)
924 return ERR_PTR(-ENOMEM);
925
926 pwm = of_pwm_get(np, con_id);
927 if (!IS_ERR(pwm)) {
928 *ptr = pwm;
929 devres_add(dev, ptr);
930 } else {
931 devres_free(ptr);
932 }
933
934 return pwm;
935}
936EXPORT_SYMBOL_GPL(devm_of_pwm_get);
937
Alexandre Courbot63543162012-08-01 19:20:58 +0900938static int devm_pwm_match(struct device *dev, void *res, void *data)
939{
940 struct pwm_device **p = res;
941
942 if (WARN_ON(!p || !*p))
943 return 0;
944
945 return *p == data;
946}
947
948/**
949 * devm_pwm_put() - resource managed pwm_put()
950 * @dev: device for PWM consumer
951 * @pwm: PWM device
952 *
953 * Release a PWM previously allocated using devm_pwm_get(). Calling this
954 * function is usually not needed because devm-allocated resources are
955 * automatically released on driver detach.
956 */
957void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
958{
959 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
960}
961EXPORT_SYMBOL_GPL(devm_pwm_put);
962
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100963/**
964 * pwm_can_sleep() - report whether PWM access will sleep
965 * @pwm: PWM device
966 *
Thierry Reding04883802015-07-27 11:58:32 +0200967 * Returns: True if accessing the PWM can sleep, false otherwise.
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100968 */
969bool pwm_can_sleep(struct pwm_device *pwm)
970{
Thierry Redingff01c942016-01-21 15:04:59 +0100971 return true;
Florian Vaussard6e69ab12013-01-28 15:00:57 +0100972}
973EXPORT_SYMBOL_GPL(pwm_can_sleep);
974
Thierry Reding62099ab2012-03-26 09:31:48 +0200975#ifdef CONFIG_DEBUG_FS
976static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
977{
978 unsigned int i;
979
980 for (i = 0; i < chip->npwm; i++) {
981 struct pwm_device *pwm = &chip->pwms[i];
Boris Brezillon39100ce2016-04-14 21:17:43 +0200982 struct pwm_state state;
983
984 pwm_get_state(pwm, &state);
Thierry Reding62099ab2012-03-26 09:31:48 +0200985
986 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
987
988 if (test_bit(PWMF_REQUESTED, &pwm->flags))
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900989 seq_puts(s, " requested");
Thierry Reding62099ab2012-03-26 09:31:48 +0200990
Boris Brezillon39100ce2016-04-14 21:17:43 +0200991 if (state.enabled)
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900992 seq_puts(s, " enabled");
Thierry Reding62099ab2012-03-26 09:31:48 +0200993
Heiko Stübner23e35232016-04-14 21:17:44 +0200994 seq_printf(s, " period: %u ns", state.period);
995 seq_printf(s, " duty: %u ns", state.duty_cycle);
996 seq_printf(s, " polarity: %s",
997 state.polarity ? "inverse" : "normal");
998
Jingoo Hanadcba1e2013-12-19 13:31:24 +0900999 seq_puts(s, "\n");
Thierry Reding62099ab2012-03-26 09:31:48 +02001000 }
1001}
1002
1003static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1004{
1005 mutex_lock(&pwm_lock);
1006 s->private = "";
1007
1008 return seq_list_start(&pwm_chips, *pos);
1009}
1010
1011static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1012{
1013 s->private = "\n";
1014
1015 return seq_list_next(v, &pwm_chips, pos);
1016}
1017
1018static void pwm_seq_stop(struct seq_file *s, void *v)
1019{
1020 mutex_unlock(&pwm_lock);
1021}
1022
1023static int pwm_seq_show(struct seq_file *s, void *v)
1024{
1025 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1026
1027 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1028 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1029 dev_name(chip->dev), chip->npwm,
1030 (chip->npwm != 1) ? "s" : "");
1031
1032 if (chip->ops->dbg_show)
1033 chip->ops->dbg_show(chip, s);
1034 else
1035 pwm_dbg_show(chip, s);
1036
1037 return 0;
1038}
1039
1040static const struct seq_operations pwm_seq_ops = {
1041 .start = pwm_seq_start,
1042 .next = pwm_seq_next,
1043 .stop = pwm_seq_stop,
1044 .show = pwm_seq_show,
1045};
1046
1047static int pwm_seq_open(struct inode *inode, struct file *file)
1048{
1049 return seq_open(file, &pwm_seq_ops);
1050}
1051
1052static const struct file_operations pwm_debugfs_ops = {
1053 .owner = THIS_MODULE,
1054 .open = pwm_seq_open,
1055 .read = seq_read,
1056 .llseek = seq_lseek,
1057 .release = seq_release,
1058};
1059
1060static int __init pwm_debugfs_init(void)
1061{
1062 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1063 &pwm_debugfs_ops);
1064
1065 return 0;
1066}
Thierry Reding62099ab2012-03-26 09:31:48 +02001067subsys_initcall(pwm_debugfs_init);
1068#endif /* CONFIG_DEBUG_FS */