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1/*
2 * Generic pwmlib implementation
3 *
4 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
5 * Copyright (C) 2011-2012 Avionic Design GmbH
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; see the file COPYING. If not, write to
19 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/pwm.h>
24#include <linux/radix-tree.h>
25#include <linux/list.h>
26#include <linux/mutex.h>
27#include <linux/err.h>
28#include <linux/slab.h>
29#include <linux/device.h>
30#include <linux/debugfs.h>
31#include <linux/seq_file.h>
32
33#include <dt-bindings/pwm/pwm.h>
34
35#define MAX_PWMS 1024
36
37static DEFINE_MUTEX(pwm_lookup_lock);
38static LIST_HEAD(pwm_lookup_list);
39static DEFINE_MUTEX(pwm_lock);
40static LIST_HEAD(pwm_chips);
41static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42static RADIX_TREE(pwm_tree, GFP_KERNEL);
43
44static struct pwm_device *pwm_to_device(unsigned int pwm)
45{
46 return radix_tree_lookup(&pwm_tree, pwm);
47}
48
49static 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);
79 }
80
81 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
82
83 kfree(chip->pwms);
84 chip->pwms = NULL;
85}
86
87static 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
110static 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
134struct 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
151 if (args->args[2] & PWM_POLARITY_INVERTED)
152 pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
153 else
154 pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
155
156 return pwm;
157}
158EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
159
160static struct pwm_device *
161of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
162{
163 struct pwm_device *pwm;
164
165 if (pc->of_pwm_n_cells < 2)
166 return ERR_PTR(-EINVAL);
167
168 if (args->args[0] >= pc->npwm)
169 return ERR_PTR(-EINVAL);
170
171 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
172 if (IS_ERR(pwm))
173 return pwm;
174
175 pwm_set_period(pwm, args->args[1]);
176
177 return pwm;
178}
179
180static void of_pwmchip_add(struct pwm_chip *chip)
181{
182 if (!chip->dev || !chip->dev->of_node)
183 return;
184
185 if (!chip->of_xlate) {
186 chip->of_xlate = of_pwm_simple_xlate;
187 chip->of_pwm_n_cells = 2;
188 }
189
190 of_node_get(chip->dev->of_node);
191}
192
193static void of_pwmchip_remove(struct pwm_chip *chip)
194{
195 if (chip->dev)
196 of_node_put(chip->dev->of_node);
197}
198
199/**
200 * pwm_set_chip_data() - set private chip data for a PWM
201 * @pwm: PWM device
202 * @data: pointer to chip-specific data
203 *
204 * Returns: 0 on success or a negative error code on failure.
205 */
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}
215EXPORT_SYMBOL_GPL(pwm_set_chip_data);
216
217/**
218 * pwm_get_chip_data() - get private chip data for a PWM
219 * @pwm: PWM device
220 *
221 * Returns: A pointer to the chip-private data for the PWM device.
222 */
223void *pwm_get_chip_data(struct pwm_device *pwm)
224{
225 return pwm ? pwm->chip_data : NULL;
226}
227EXPORT_SYMBOL_GPL(pwm_get_chip_data);
228
229/**
230 * pwmchip_add_with_polarity() - register a new PWM chip
231 * @chip: the PWM chip to add
232 * @polarity: initial polarity of PWM channels
233 *
234 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
235 * will be used. The initial polarity for all channels is specified by the
236 * @polarity parameter.
237 *
238 * Returns: 0 on success or a negative error code on failure.
239 */
240int pwmchip_add_with_polarity(struct pwm_chip *chip,
241 enum pwm_polarity polarity)
242{
243 struct pwm_device *pwm;
244 unsigned int i;
245 int ret;
246
247 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
248 !chip->ops->enable || !chip->ops->disable || !chip->npwm)
249 return -EINVAL;
250
251 mutex_lock(&pwm_lock);
252
253 ret = alloc_pwms(chip->base, chip->npwm);
254 if (ret < 0)
255 goto out;
256
257 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
258 if (!chip->pwms) {
259 ret = -ENOMEM;
260 goto out;
261 }
262
263 chip->base = ret;
264
265 for (i = 0; i < chip->npwm; i++) {
266 pwm = &chip->pwms[i];
267
268 pwm->chip = chip;
269 pwm->pwm = chip->base + i;
270 pwm->hwpwm = i;
271 pwm->polarity = polarity;
272 mutex_init(&pwm->lock);
273
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
284 if (IS_ENABLED(CONFIG_OF))
285 of_pwmchip_add(chip);
286
287 pwmchip_sysfs_export(chip);
288
289out:
290 mutex_unlock(&pwm_lock);
291 return ret;
292}
293EXPORT_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.
301 *
302 * Returns: 0 on success or a negative error code on failure.
303 */
304int pwmchip_add(struct pwm_chip *chip)
305{
306 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
307}
308EXPORT_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.
316 *
317 * Returns: 0 on success or a negative error code on failure.
318 */
319int pwmchip_remove(struct pwm_chip *chip)
320{
321 unsigned int i;
322 int ret = 0;
323
324 mutex_lock(&pwm_lock);
325
326 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 }
333 }
334
335 list_del_init(&chip->list);
336
337 if (IS_ENABLED(CONFIG_OF))
338 of_pwmchip_remove(chip);
339
340 free_pwms(chip);
341
342 pwmchip_sysfs_unexport(chip);
343
344out:
345 mutex_unlock(&pwm_lock);
346 return ret;
347}
348EXPORT_SYMBOL_GPL(pwmchip_remove);
349
350/**
351 * pwm_request() - request a PWM device
352 * @pwm: global PWM device index
353 * @label: PWM device label
354 *
355 * This function is deprecated, use pwm_get() instead.
356 *
357 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
358 * failure.
359 */
360struct pwm_device *pwm_request(int pwm, const char *label)
361{
362 struct pwm_device *dev;
363 int err;
364
365 if (pwm < 0 || pwm >= MAX_PWMS)
366 return ERR_PTR(-EINVAL);
367
368 mutex_lock(&pwm_lock);
369
370 dev = pwm_to_device(pwm);
371 if (!dev) {
372 dev = ERR_PTR(-EPROBE_DEFER);
373 goto out;
374 }
375
376 err = pwm_device_request(dev, label);
377 if (err < 0)
378 dev = ERR_PTR(err);
379
380out:
381 mutex_unlock(&pwm_lock);
382
383 return dev;
384}
385EXPORT_SYMBOL_GPL(pwm_request);
386
387/**
388 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
389 * @chip: PWM chip
390 * @index: per-chip index of the PWM to request
391 * @label: a literal description string of this PWM
392 *
393 * Returns: A pointer to the PWM device at the given index of the given PWM
394 * chip. A negative error code is returned if the index is not valid for the
395 * specified PWM chip or if the PWM device cannot be requested.
396 */
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/**
420 * pwm_free() - free a PWM device
421 * @pwm: PWM device
422 *
423 * This function is deprecated, use pwm_put() instead.
424 */
425void pwm_free(struct pwm_device *pwm)
426{
427 pwm_put(pwm);
428}
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
436 *
437 * Returns: 0 on success or a negative error code on failure.
438 */
439int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
440{
441 int err;
442
443 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
444 return -EINVAL;
445
446 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
447 if (err)
448 return err;
449
450 pwm->duty_cycle = duty_ns;
451 pwm->period = period_ns;
452
453 return 0;
454}
455EXPORT_SYMBOL_GPL(pwm_config);
456
457/**
458 * pwm_set_polarity() - configure the polarity of a PWM signal
459 * @pwm: PWM device
460 * @polarity: new polarity of the PWM signal
461 *
462 * Note that the polarity cannot be configured while the PWM device is
463 * enabled.
464 *
465 * Returns: 0 on success or a negative error code on failure.
466 */
467int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
468{
469 int err;
470
471 if (!pwm || !pwm->chip->ops)
472 return -EINVAL;
473
474 if (!pwm->chip->ops->set_polarity)
475 return -ENOSYS;
476
477 mutex_lock(&pwm->lock);
478
479 if (pwm_is_enabled(pwm)) {
480 err = -EBUSY;
481 goto unlock;
482 }
483
484 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
485 if (err)
486 goto unlock;
487
488 pwm->polarity = polarity;
489
490unlock:
491 mutex_unlock(&pwm->lock);
492 return err;
493}
494EXPORT_SYMBOL_GPL(pwm_set_polarity);
495
496/**
497 * pwm_enable() - start a PWM output toggling
498 * @pwm: PWM device
499 *
500 * Returns: 0 on success or a negative error code on failure.
501 */
502int pwm_enable(struct pwm_device *pwm)
503{
504 int err = 0;
505
506 if (!pwm)
507 return -EINVAL;
508
509 mutex_lock(&pwm->lock);
510
511 if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
512 err = pwm->chip->ops->enable(pwm->chip, pwm);
513 if (err)
514 clear_bit(PWMF_ENABLED, &pwm->flags);
515 }
516
517 mutex_unlock(&pwm->lock);
518
519 return err;
520}
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{
529 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
530 pwm->chip->ops->disable(pwm->chip, pwm);
531}
532EXPORT_SYMBOL_GPL(pwm_disable);
533
534static 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/**
552 * of_pwm_get() - request a PWM via the PWM framework
553 * @np: device node to get the PWM from
554 * @con_id: consumer name
555 *
556 * Returns the PWM device parsed from the phandle and index specified in the
557 * "pwms" property of a device tree node or a negative error-code on failure.
558 * Values parsed from the device tree are stored in the returned PWM device
559 * object.
560 *
561 * If con_id is NULL, the first PWM device listed in the "pwms" property will
562 * be requested. Otherwise the "pwm-names" property is used to do a reverse
563 * lookup of the PWM index. This also means that the "pwm-names" property
564 * becomes mandatory for devices that look up the PWM device via the con_id
565 * parameter.
566 *
567 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
568 * error code on failure.
569 */
570struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
571{
572 struct pwm_device *pwm = NULL;
573 struct of_phandle_args args;
574 struct pwm_chip *pc;
575 int index = 0;
576 int err;
577
578 if (con_id) {
579 index = of_property_match_string(np, "pwm-names", con_id);
580 if (index < 0)
581 return ERR_PTR(index);
582 }
583
584 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
585 &args);
586 if (err) {
587 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
588 return ERR_PTR(err);
589 }
590
591 pc = of_node_to_pwmchip(args.np);
592 if (IS_ERR(pc)) {
593 pr_debug("%s(): PWM chip not found\n", __func__);
594 pwm = ERR_CAST(pc);
595 goto put;
596 }
597
598 if (args.args_count != pc->of_pwm_n_cells) {
599 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
600 args.np->full_name);
601 pwm = ERR_PTR(-EINVAL);
602 goto put;
603 }
604
605 pwm = pc->of_xlate(pc, &args);
606 if (IS_ERR(pwm))
607 goto put;
608
609 /*
610 * If a consumer name was not given, try to look it up from the
611 * "pwm-names" property if it exists. Otherwise use the name of
612 * the user device node.
613 */
614 if (!con_id) {
615 err = of_property_read_string_index(np, "pwm-names", index,
616 &con_id);
617 if (err < 0)
618 con_id = np->name;
619 }
620
621 pwm->label = con_id;
622
623put:
624 of_node_put(args.np);
625
626 return pwm;
627}
628EXPORT_SYMBOL_GPL(of_pwm_get);
629
630/**
631 * pwm_add_table() - register PWM device consumers
632 * @table: array of consumers to register
633 * @num: number of consumers in table
634 */
635void pwm_add_table(struct pwm_lookup *table, size_t num)
636{
637 mutex_lock(&pwm_lookup_lock);
638
639 while (num--) {
640 list_add_tail(&table->list, &pwm_lookup_list);
641 table++;
642 }
643
644 mutex_unlock(&pwm_lookup_lock);
645}
646
647/**
648 * 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/**
665 * pwm_get() - look up and request a PWM device
666 * @dev: device for PWM consumer
667 * @con_id: consumer name
668 *
669 * Lookup is first attempted using DT. If the device was not instantiated from
670 * a device tree, a PWM chip and a relative index is looked up via a table
671 * supplied by board setup code (see pwm_add_table()).
672 *
673 * Once a PWM chip has been found the specified PWM device will be requested
674 * and is ready to be used.
675 *
676 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
677 * error code on failure.
678 */
679struct pwm_device *pwm_get(struct device *dev, const char *con_id)
680{
681 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
682 const char *dev_id = dev ? dev_name(dev) : NULL;
683 struct pwm_chip *chip = NULL;
684 unsigned int best = 0;
685 struct pwm_lookup *p, *chosen = NULL;
686 unsigned int match;
687
688 /* look up via DT first */
689 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
690 return of_pwm_get(dev->of_node, con_id);
691
692 /*
693 * We look up the provider in the static table typically provided by
694 * board setup code. We first try to lookup the consumer device by
695 * name. If the consumer device was passed in as NULL or if no match
696 * was found, we try to find the consumer by directly looking it up
697 * by name.
698 *
699 * If a match is found, the provider PWM chip is looked up by name
700 * and a PWM device is requested using the PWM device per-chip index.
701 *
702 * The lookup algorithm was shamelessly taken from the clock
703 * framework:
704 *
705 * We do slightly fuzzy matching here:
706 * An entry with a NULL ID is assumed to be a wildcard.
707 * If an entry has a device ID, it must match
708 * If an entry has a connection ID, it must match
709 * Then we take the most specific entry - with the following order
710 * of precedence: dev+con > dev only > con only.
711 */
712 mutex_lock(&pwm_lookup_lock);
713
714 list_for_each_entry(p, &pwm_lookup_list, list) {
715 match = 0;
716
717 if (p->dev_id) {
718 if (!dev_id || strcmp(p->dev_id, dev_id))
719 continue;
720
721 match += 2;
722 }
723
724 if (p->con_id) {
725 if (!con_id || strcmp(p->con_id, con_id))
726 continue;
727
728 match += 1;
729 }
730
731 if (match > best) {
732 chosen = p;
733
734 if (match != 3)
735 best = match;
736 else
737 break;
738 }
739 }
740
741 if (!chosen) {
742 pwm = ERR_PTR(-ENODEV);
743 goto out;
744 }
745
746 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);
751 if (IS_ERR(pwm))
752 goto out;
753
754 pwm_set_period(pwm, chosen->period);
755 pwm_set_polarity(pwm, chosen->polarity);
756
757out:
758 mutex_unlock(&pwm_lookup_lock);
759 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)) {
775 pr_warn("PWM device already freed\n");
776 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
790static 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.
802 *
803 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
804 * error code on failure.
805 */
806struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
807{
808 struct pwm_device **ptr, *pwm;
809
810 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
811 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
826/**
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.
834 *
835 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
836 * error code on failure.
837 */
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
843 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
844 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
859static 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
884/**
885 * pwm_can_sleep() - report whether PWM access will sleep
886 * @pwm: PWM device
887 *
888 * Returns: True if accessing the PWM can sleep, false otherwise.
889 */
890bool pwm_can_sleep(struct pwm_device *pwm)
891{
892 return true;
893}
894EXPORT_SYMBOL_GPL(pwm_can_sleep);
895
896#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))
907 seq_puts(s, " requested");
908
909 if (pwm_is_enabled(pwm))
910 seq_puts(s, " enabled");
911
912 seq_puts(s, "\n");
913 }
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}
980subsys_initcall(pwm_debugfs_init);
981#endif /* CONFIG_DEBUG_FS */
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#include <linux/acpi.h>
10#include <linux/module.h>
11#include <linux/pwm.h>
12#include <linux/radix-tree.h>
13#include <linux/list.h>
14#include <linux/mutex.h>
15#include <linux/err.h>
16#include <linux/slab.h>
17#include <linux/device.h>
18#include <linux/debugfs.h>
19#include <linux/seq_file.h>
20
21#include <dt-bindings/pwm/pwm.h>
22
23#define CREATE_TRACE_POINTS
24#include <trace/events/pwm.h>
25
26#define MAX_PWMS 1024
27
28static DEFINE_MUTEX(pwm_lookup_lock);
29static LIST_HEAD(pwm_lookup_list);
30static DEFINE_MUTEX(pwm_lock);
31static LIST_HEAD(pwm_chips);
32static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
33static RADIX_TREE(pwm_tree, GFP_KERNEL);
34
35static struct pwm_device *pwm_to_device(unsigned int pwm)
36{
37 return radix_tree_lookup(&pwm_tree, pwm);
38}
39
40static int alloc_pwms(int pwm, unsigned int count)
41{
42 unsigned int from = 0;
43 unsigned int start;
44
45 if (pwm >= MAX_PWMS)
46 return -EINVAL;
47
48 if (pwm >= 0)
49 from = pwm;
50
51 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
52 count, 0);
53
54 if (pwm >= 0 && start != pwm)
55 return -EEXIST;
56
57 if (start + count > MAX_PWMS)
58 return -ENOSPC;
59
60 return start;
61}
62
63static void free_pwms(struct pwm_chip *chip)
64{
65 unsigned int i;
66
67 for (i = 0; i < chip->npwm; i++) {
68 struct pwm_device *pwm = &chip->pwms[i];
69
70 radix_tree_delete(&pwm_tree, pwm->pwm);
71 }
72
73 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
74
75 kfree(chip->pwms);
76 chip->pwms = NULL;
77}
78
79static struct pwm_chip *pwmchip_find_by_name(const char *name)
80{
81 struct pwm_chip *chip;
82
83 if (!name)
84 return NULL;
85
86 mutex_lock(&pwm_lock);
87
88 list_for_each_entry(chip, &pwm_chips, list) {
89 const char *chip_name = dev_name(chip->dev);
90
91 if (chip_name && strcmp(chip_name, name) == 0) {
92 mutex_unlock(&pwm_lock);
93 return chip;
94 }
95 }
96
97 mutex_unlock(&pwm_lock);
98
99 return NULL;
100}
101
102static int pwm_device_request(struct pwm_device *pwm, const char *label)
103{
104 int err;
105
106 if (test_bit(PWMF_REQUESTED, &pwm->flags))
107 return -EBUSY;
108
109 if (!try_module_get(pwm->chip->ops->owner))
110 return -ENODEV;
111
112 if (pwm->chip->ops->request) {
113 err = pwm->chip->ops->request(pwm->chip, pwm);
114 if (err) {
115 module_put(pwm->chip->ops->owner);
116 return err;
117 }
118 }
119
120 if (pwm->chip->ops->get_state) {
121 pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
122 trace_pwm_get(pwm, &pwm->state);
123
124 if (IS_ENABLED(CONFIG_PWM_DEBUG))
125 pwm->last = pwm->state;
126 }
127
128 set_bit(PWMF_REQUESTED, &pwm->flags);
129 pwm->label = label;
130
131 return 0;
132}
133
134struct 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 /* check, whether the driver supports a third cell for flags */
140 if (pc->of_pwm_n_cells < 3)
141 return ERR_PTR(-EINVAL);
142
143 /* flags in the third cell are optional */
144 if (args->args_count < 2)
145 return ERR_PTR(-EINVAL);
146
147 if (args->args[0] >= pc->npwm)
148 return ERR_PTR(-EINVAL);
149
150 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
151 if (IS_ERR(pwm))
152 return pwm;
153
154 pwm->args.period = args->args[1];
155 pwm->args.polarity = PWM_POLARITY_NORMAL;
156
157 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
158 pwm->args.polarity = PWM_POLARITY_INVERSED;
159
160 return pwm;
161}
162EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
163
164static struct pwm_device *
165of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
166{
167 struct pwm_device *pwm;
168
169 /* sanity check driver support */
170 if (pc->of_pwm_n_cells < 2)
171 return ERR_PTR(-EINVAL);
172
173 /* all cells are required */
174 if (args->args_count != pc->of_pwm_n_cells)
175 return ERR_PTR(-EINVAL);
176
177 if (args->args[0] >= pc->npwm)
178 return ERR_PTR(-EINVAL);
179
180 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
181 if (IS_ERR(pwm))
182 return pwm;
183
184 pwm->args.period = args->args[1];
185
186 return pwm;
187}
188
189static void of_pwmchip_add(struct pwm_chip *chip)
190{
191 if (!chip->dev || !chip->dev->of_node)
192 return;
193
194 if (!chip->of_xlate) {
195 chip->of_xlate = of_pwm_simple_xlate;
196 chip->of_pwm_n_cells = 2;
197 }
198
199 of_node_get(chip->dev->of_node);
200}
201
202static void of_pwmchip_remove(struct pwm_chip *chip)
203{
204 if (chip->dev)
205 of_node_put(chip->dev->of_node);
206}
207
208/**
209 * pwm_set_chip_data() - set private chip data for a PWM
210 * @pwm: PWM device
211 * @data: pointer to chip-specific data
212 *
213 * Returns: 0 on success or a negative error code on failure.
214 */
215int pwm_set_chip_data(struct pwm_device *pwm, void *data)
216{
217 if (!pwm)
218 return -EINVAL;
219
220 pwm->chip_data = data;
221
222 return 0;
223}
224EXPORT_SYMBOL_GPL(pwm_set_chip_data);
225
226/**
227 * pwm_get_chip_data() - get private chip data for a PWM
228 * @pwm: PWM device
229 *
230 * Returns: A pointer to the chip-private data for the PWM device.
231 */
232void *pwm_get_chip_data(struct pwm_device *pwm)
233{
234 return pwm ? pwm->chip_data : NULL;
235}
236EXPORT_SYMBOL_GPL(pwm_get_chip_data);
237
238static bool pwm_ops_check(const struct pwm_chip *chip)
239{
240
241 const struct pwm_ops *ops = chip->ops;
242
243 /* driver supports legacy, non-atomic operation */
244 if (ops->config && ops->enable && ops->disable) {
245 if (IS_ENABLED(CONFIG_PWM_DEBUG))
246 dev_warn(chip->dev,
247 "Driver needs updating to atomic API\n");
248
249 return true;
250 }
251
252 if (!ops->apply)
253 return false;
254
255 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
256 dev_warn(chip->dev,
257 "Please implement the .get_state() callback\n");
258
259 return true;
260}
261
262/**
263 * pwmchip_add_with_polarity() - register a new PWM chip
264 * @chip: the PWM chip to add
265 * @polarity: initial polarity of PWM channels
266 *
267 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
268 * will be used. The initial polarity for all channels is specified by the
269 * @polarity parameter.
270 *
271 * Returns: 0 on success or a negative error code on failure.
272 */
273int pwmchip_add_with_polarity(struct pwm_chip *chip,
274 enum pwm_polarity polarity)
275{
276 struct pwm_device *pwm;
277 unsigned int i;
278 int ret;
279
280 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
281 return -EINVAL;
282
283 if (!pwm_ops_check(chip))
284 return -EINVAL;
285
286 mutex_lock(&pwm_lock);
287
288 ret = alloc_pwms(chip->base, chip->npwm);
289 if (ret < 0)
290 goto out;
291
292 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
293 if (!chip->pwms) {
294 ret = -ENOMEM;
295 goto out;
296 }
297
298 chip->base = ret;
299
300 for (i = 0; i < chip->npwm; i++) {
301 pwm = &chip->pwms[i];
302
303 pwm->chip = chip;
304 pwm->pwm = chip->base + i;
305 pwm->hwpwm = i;
306 pwm->state.polarity = polarity;
307
308 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
309 }
310
311 bitmap_set(allocated_pwms, chip->base, chip->npwm);
312
313 INIT_LIST_HEAD(&chip->list);
314 list_add(&chip->list, &pwm_chips);
315
316 ret = 0;
317
318 if (IS_ENABLED(CONFIG_OF))
319 of_pwmchip_add(chip);
320
321out:
322 mutex_unlock(&pwm_lock);
323
324 if (!ret)
325 pwmchip_sysfs_export(chip);
326
327 return ret;
328}
329EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
330
331/**
332 * pwmchip_add() - register a new PWM chip
333 * @chip: the PWM chip to add
334 *
335 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
336 * will be used. The initial polarity for all channels is normal.
337 *
338 * Returns: 0 on success or a negative error code on failure.
339 */
340int pwmchip_add(struct pwm_chip *chip)
341{
342 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
343}
344EXPORT_SYMBOL_GPL(pwmchip_add);
345
346/**
347 * pwmchip_remove() - remove a PWM chip
348 * @chip: the PWM chip to remove
349 *
350 * Removes a PWM chip. This function may return busy if the PWM chip provides
351 * a PWM device that is still requested.
352 *
353 * Returns: 0 on success or a negative error code on failure.
354 */
355int pwmchip_remove(struct pwm_chip *chip)
356{
357 unsigned int i;
358 int ret = 0;
359
360 pwmchip_sysfs_unexport(chip);
361
362 mutex_lock(&pwm_lock);
363
364 for (i = 0; i < chip->npwm; i++) {
365 struct pwm_device *pwm = &chip->pwms[i];
366
367 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
368 ret = -EBUSY;
369 goto out;
370 }
371 }
372
373 list_del_init(&chip->list);
374
375 if (IS_ENABLED(CONFIG_OF))
376 of_pwmchip_remove(chip);
377
378 free_pwms(chip);
379
380out:
381 mutex_unlock(&pwm_lock);
382 return ret;
383}
384EXPORT_SYMBOL_GPL(pwmchip_remove);
385
386/**
387 * pwm_request() - request a PWM device
388 * @pwm: global PWM device index
389 * @label: PWM device label
390 *
391 * This function is deprecated, use pwm_get() instead.
392 *
393 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
394 * failure.
395 */
396struct pwm_device *pwm_request(int pwm, const char *label)
397{
398 struct pwm_device *dev;
399 int err;
400
401 if (pwm < 0 || pwm >= MAX_PWMS)
402 return ERR_PTR(-EINVAL);
403
404 mutex_lock(&pwm_lock);
405
406 dev = pwm_to_device(pwm);
407 if (!dev) {
408 dev = ERR_PTR(-EPROBE_DEFER);
409 goto out;
410 }
411
412 err = pwm_device_request(dev, label);
413 if (err < 0)
414 dev = ERR_PTR(err);
415
416out:
417 mutex_unlock(&pwm_lock);
418
419 return dev;
420}
421EXPORT_SYMBOL_GPL(pwm_request);
422
423/**
424 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
425 * @chip: PWM chip
426 * @index: per-chip index of the PWM to request
427 * @label: a literal description string of this PWM
428 *
429 * Returns: A pointer to the PWM device at the given index of the given PWM
430 * chip. A negative error code is returned if the index is not valid for the
431 * specified PWM chip or if the PWM device cannot be requested.
432 */
433struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
434 unsigned int index,
435 const char *label)
436{
437 struct pwm_device *pwm;
438 int err;
439
440 if (!chip || index >= chip->npwm)
441 return ERR_PTR(-EINVAL);
442
443 mutex_lock(&pwm_lock);
444 pwm = &chip->pwms[index];
445
446 err = pwm_device_request(pwm, label);
447 if (err < 0)
448 pwm = ERR_PTR(err);
449
450 mutex_unlock(&pwm_lock);
451 return pwm;
452}
453EXPORT_SYMBOL_GPL(pwm_request_from_chip);
454
455/**
456 * pwm_free() - free a PWM device
457 * @pwm: PWM device
458 *
459 * This function is deprecated, use pwm_put() instead.
460 */
461void pwm_free(struct pwm_device *pwm)
462{
463 pwm_put(pwm);
464}
465EXPORT_SYMBOL_GPL(pwm_free);
466
467static void pwm_apply_state_debug(struct pwm_device *pwm,
468 const struct pwm_state *state)
469{
470 struct pwm_state *last = &pwm->last;
471 struct pwm_chip *chip = pwm->chip;
472 struct pwm_state s1, s2;
473 int err;
474
475 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
476 return;
477
478 /* No reasonable diagnosis possible without .get_state() */
479 if (!chip->ops->get_state)
480 return;
481
482 /*
483 * *state was just applied. Read out the hardware state and do some
484 * checks.
485 */
486
487 chip->ops->get_state(chip, pwm, &s1);
488 trace_pwm_get(pwm, &s1);
489
490 /*
491 * The lowlevel driver either ignored .polarity (which is a bug) or as
492 * best effort inverted .polarity and fixed .duty_cycle respectively.
493 * Undo this inversion and fixup for further tests.
494 */
495 if (s1.enabled && s1.polarity != state->polarity) {
496 s2.polarity = state->polarity;
497 s2.duty_cycle = s1.period - s1.duty_cycle;
498 s2.period = s1.period;
499 s2.enabled = s1.enabled;
500 } else {
501 s2 = s1;
502 }
503
504 if (s2.polarity != state->polarity &&
505 state->duty_cycle < state->period)
506 dev_warn(chip->dev, ".apply ignored .polarity\n");
507
508 if (state->enabled &&
509 last->polarity == state->polarity &&
510 last->period > s2.period &&
511 last->period <= state->period)
512 dev_warn(chip->dev,
513 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
514 state->period, s2.period, last->period);
515
516 if (state->enabled && state->period < s2.period)
517 dev_warn(chip->dev,
518 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
519 state->period, s2.period);
520
521 if (state->enabled &&
522 last->polarity == state->polarity &&
523 last->period == s2.period &&
524 last->duty_cycle > s2.duty_cycle &&
525 last->duty_cycle <= state->duty_cycle)
526 dev_warn(chip->dev,
527 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
528 state->duty_cycle, state->period,
529 s2.duty_cycle, s2.period,
530 last->duty_cycle, last->period);
531
532 if (state->enabled && state->duty_cycle < s2.duty_cycle)
533 dev_warn(chip->dev,
534 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
535 state->duty_cycle, state->period,
536 s2.duty_cycle, s2.period);
537
538 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
539 dev_warn(chip->dev,
540 "requested disabled, but yielded enabled with duty > 0\n");
541
542 /* reapply the state that the driver reported being configured. */
543 err = chip->ops->apply(chip, pwm, &s1);
544 if (err) {
545 *last = s1;
546 dev_err(chip->dev, "failed to reapply current setting\n");
547 return;
548 }
549
550 trace_pwm_apply(pwm, &s1);
551
552 chip->ops->get_state(chip, pwm, last);
553 trace_pwm_get(pwm, last);
554
555 /* reapplication of the current state should give an exact match */
556 if (s1.enabled != last->enabled ||
557 s1.polarity != last->polarity ||
558 (s1.enabled && s1.period != last->period) ||
559 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
560 dev_err(chip->dev,
561 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
562 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
563 last->enabled, last->polarity, last->duty_cycle,
564 last->period);
565 }
566}
567
568/**
569 * pwm_apply_state() - atomically apply a new state to a PWM device
570 * @pwm: PWM device
571 * @state: new state to apply
572 */
573int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
574{
575 struct pwm_chip *chip;
576 int err;
577
578 if (!pwm || !state || !state->period ||
579 state->duty_cycle > state->period)
580 return -EINVAL;
581
582 chip = pwm->chip;
583
584 if (state->period == pwm->state.period &&
585 state->duty_cycle == pwm->state.duty_cycle &&
586 state->polarity == pwm->state.polarity &&
587 state->enabled == pwm->state.enabled)
588 return 0;
589
590 if (chip->ops->apply) {
591 err = chip->ops->apply(chip, pwm, state);
592 if (err)
593 return err;
594
595 trace_pwm_apply(pwm, state);
596
597 pwm->state = *state;
598
599 /*
600 * only do this after pwm->state was applied as some
601 * implementations of .get_state depend on this
602 */
603 pwm_apply_state_debug(pwm, state);
604 } else {
605 /*
606 * FIXME: restore the initial state in case of error.
607 */
608 if (state->polarity != pwm->state.polarity) {
609 if (!chip->ops->set_polarity)
610 return -ENOTSUPP;
611
612 /*
613 * Changing the polarity of a running PWM is
614 * only allowed when the PWM driver implements
615 * ->apply().
616 */
617 if (pwm->state.enabled) {
618 chip->ops->disable(chip, pwm);
619 pwm->state.enabled = false;
620 }
621
622 err = chip->ops->set_polarity(chip, pwm,
623 state->polarity);
624 if (err)
625 return err;
626
627 pwm->state.polarity = state->polarity;
628 }
629
630 if (state->period != pwm->state.period ||
631 state->duty_cycle != pwm->state.duty_cycle) {
632 err = chip->ops->config(pwm->chip, pwm,
633 state->duty_cycle,
634 state->period);
635 if (err)
636 return err;
637
638 pwm->state.duty_cycle = state->duty_cycle;
639 pwm->state.period = state->period;
640 }
641
642 if (state->enabled != pwm->state.enabled) {
643 if (state->enabled) {
644 err = chip->ops->enable(chip, pwm);
645 if (err)
646 return err;
647 } else {
648 chip->ops->disable(chip, pwm);
649 }
650
651 pwm->state.enabled = state->enabled;
652 }
653 }
654
655 return 0;
656}
657EXPORT_SYMBOL_GPL(pwm_apply_state);
658
659/**
660 * pwm_capture() - capture and report a PWM signal
661 * @pwm: PWM device
662 * @result: structure to fill with capture result
663 * @timeout: time to wait, in milliseconds, before giving up on capture
664 *
665 * Returns: 0 on success or a negative error code on failure.
666 */
667int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
668 unsigned long timeout)
669{
670 int err;
671
672 if (!pwm || !pwm->chip->ops)
673 return -EINVAL;
674
675 if (!pwm->chip->ops->capture)
676 return -ENOSYS;
677
678 mutex_lock(&pwm_lock);
679 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
680 mutex_unlock(&pwm_lock);
681
682 return err;
683}
684EXPORT_SYMBOL_GPL(pwm_capture);
685
686/**
687 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
688 * @pwm: PWM device
689 *
690 * This function will adjust the PWM config to the PWM arguments provided
691 * by the DT or PWM lookup table. This is particularly useful to adapt
692 * the bootloader config to the Linux one.
693 */
694int pwm_adjust_config(struct pwm_device *pwm)
695{
696 struct pwm_state state;
697 struct pwm_args pargs;
698
699 pwm_get_args(pwm, &pargs);
700 pwm_get_state(pwm, &state);
701
702 /*
703 * If the current period is zero it means that either the PWM driver
704 * does not support initial state retrieval or the PWM has not yet
705 * been configured.
706 *
707 * In either case, we setup the new period and polarity, and assign a
708 * duty cycle of 0.
709 */
710 if (!state.period) {
711 state.duty_cycle = 0;
712 state.period = pargs.period;
713 state.polarity = pargs.polarity;
714
715 return pwm_apply_state(pwm, &state);
716 }
717
718 /*
719 * Adjust the PWM duty cycle/period based on the period value provided
720 * in PWM args.
721 */
722 if (pargs.period != state.period) {
723 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
724
725 do_div(dutycycle, state.period);
726 state.duty_cycle = dutycycle;
727 state.period = pargs.period;
728 }
729
730 /*
731 * If the polarity changed, we should also change the duty cycle.
732 */
733 if (pargs.polarity != state.polarity) {
734 state.polarity = pargs.polarity;
735 state.duty_cycle = state.period - state.duty_cycle;
736 }
737
738 return pwm_apply_state(pwm, &state);
739}
740EXPORT_SYMBOL_GPL(pwm_adjust_config);
741
742static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
743{
744 struct pwm_chip *chip;
745
746 mutex_lock(&pwm_lock);
747
748 list_for_each_entry(chip, &pwm_chips, list)
749 if (chip->dev && chip->dev->of_node == np) {
750 mutex_unlock(&pwm_lock);
751 return chip;
752 }
753
754 mutex_unlock(&pwm_lock);
755
756 return ERR_PTR(-EPROBE_DEFER);
757}
758
759static struct device_link *pwm_device_link_add(struct device *dev,
760 struct pwm_device *pwm)
761{
762 struct device_link *dl;
763
764 if (!dev) {
765 /*
766 * No device for the PWM consumer has been provided. It may
767 * impact the PM sequence ordering: the PWM supplier may get
768 * suspended before the consumer.
769 */
770 dev_warn(pwm->chip->dev,
771 "No consumer device specified to create a link to\n");
772 return NULL;
773 }
774
775 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
776 if (!dl) {
777 dev_err(dev, "failed to create device link to %s\n",
778 dev_name(pwm->chip->dev));
779 return ERR_PTR(-EINVAL);
780 }
781
782 return dl;
783}
784
785/**
786 * of_pwm_get() - request a PWM via the PWM framework
787 * @dev: device for PWM consumer
788 * @np: device node to get the PWM from
789 * @con_id: consumer name
790 *
791 * Returns the PWM device parsed from the phandle and index specified in the
792 * "pwms" property of a device tree node or a negative error-code on failure.
793 * Values parsed from the device tree are stored in the returned PWM device
794 * object.
795 *
796 * If con_id is NULL, the first PWM device listed in the "pwms" property will
797 * be requested. Otherwise the "pwm-names" property is used to do a reverse
798 * lookup of the PWM index. This also means that the "pwm-names" property
799 * becomes mandatory for devices that look up the PWM device via the con_id
800 * parameter.
801 *
802 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
803 * error code on failure.
804 */
805struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
806 const char *con_id)
807{
808 struct pwm_device *pwm = NULL;
809 struct of_phandle_args args;
810 struct device_link *dl;
811 struct pwm_chip *pc;
812 int index = 0;
813 int err;
814
815 if (con_id) {
816 index = of_property_match_string(np, "pwm-names", con_id);
817 if (index < 0)
818 return ERR_PTR(index);
819 }
820
821 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
822 &args);
823 if (err) {
824 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
825 return ERR_PTR(err);
826 }
827
828 pc = of_node_to_pwmchip(args.np);
829 if (IS_ERR(pc)) {
830 if (PTR_ERR(pc) != -EPROBE_DEFER)
831 pr_err("%s(): PWM chip not found\n", __func__);
832
833 pwm = ERR_CAST(pc);
834 goto put;
835 }
836
837 pwm = pc->of_xlate(pc, &args);
838 if (IS_ERR(pwm))
839 goto put;
840
841 dl = pwm_device_link_add(dev, pwm);
842 if (IS_ERR(dl)) {
843 /* of_xlate ended up calling pwm_request_from_chip() */
844 pwm_free(pwm);
845 pwm = ERR_CAST(dl);
846 goto put;
847 }
848
849 /*
850 * If a consumer name was not given, try to look it up from the
851 * "pwm-names" property if it exists. Otherwise use the name of
852 * the user device node.
853 */
854 if (!con_id) {
855 err = of_property_read_string_index(np, "pwm-names", index,
856 &con_id);
857 if (err < 0)
858 con_id = np->name;
859 }
860
861 pwm->label = con_id;
862
863put:
864 of_node_put(args.np);
865
866 return pwm;
867}
868EXPORT_SYMBOL_GPL(of_pwm_get);
869
870#if IS_ENABLED(CONFIG_ACPI)
871static struct pwm_chip *device_to_pwmchip(struct device *dev)
872{
873 struct pwm_chip *chip;
874
875 mutex_lock(&pwm_lock);
876
877 list_for_each_entry(chip, &pwm_chips, list) {
878 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
879
880 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
881 mutex_unlock(&pwm_lock);
882 return chip;
883 }
884 }
885
886 mutex_unlock(&pwm_lock);
887
888 return ERR_PTR(-EPROBE_DEFER);
889}
890#endif
891
892/**
893 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
894 * @fwnode: firmware node to get the "pwm" property from
895 *
896 * Returns the PWM device parsed from the fwnode and index specified in the
897 * "pwms" property or a negative error-code on failure.
898 * Values parsed from the device tree are stored in the returned PWM device
899 * object.
900 *
901 * This is analogous to of_pwm_get() except con_id is not yet supported.
902 * ACPI entries must look like
903 * Package () {"pwms", Package ()
904 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
905 *
906 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
907 * error code on failure.
908 */
909static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
910{
911 struct pwm_device *pwm = ERR_PTR(-ENODEV);
912#if IS_ENABLED(CONFIG_ACPI)
913 struct fwnode_reference_args args;
914 struct acpi_device *acpi;
915 struct pwm_chip *chip;
916 int ret;
917
918 memset(&args, 0, sizeof(args));
919
920 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
921 if (ret < 0)
922 return ERR_PTR(ret);
923
924 acpi = to_acpi_device_node(args.fwnode);
925 if (!acpi)
926 return ERR_PTR(-EINVAL);
927
928 if (args.nargs < 2)
929 return ERR_PTR(-EPROTO);
930
931 chip = device_to_pwmchip(&acpi->dev);
932 if (IS_ERR(chip))
933 return ERR_CAST(chip);
934
935 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
936 if (IS_ERR(pwm))
937 return pwm;
938
939 pwm->args.period = args.args[1];
940 pwm->args.polarity = PWM_POLARITY_NORMAL;
941
942 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
943 pwm->args.polarity = PWM_POLARITY_INVERSED;
944#endif
945
946 return pwm;
947}
948
949/**
950 * pwm_add_table() - register PWM device consumers
951 * @table: array of consumers to register
952 * @num: number of consumers in table
953 */
954void pwm_add_table(struct pwm_lookup *table, size_t num)
955{
956 mutex_lock(&pwm_lookup_lock);
957
958 while (num--) {
959 list_add_tail(&table->list, &pwm_lookup_list);
960 table++;
961 }
962
963 mutex_unlock(&pwm_lookup_lock);
964}
965
966/**
967 * pwm_remove_table() - unregister PWM device consumers
968 * @table: array of consumers to unregister
969 * @num: number of consumers in table
970 */
971void pwm_remove_table(struct pwm_lookup *table, size_t num)
972{
973 mutex_lock(&pwm_lookup_lock);
974
975 while (num--) {
976 list_del(&table->list);
977 table++;
978 }
979
980 mutex_unlock(&pwm_lookup_lock);
981}
982
983/**
984 * pwm_get() - look up and request a PWM device
985 * @dev: device for PWM consumer
986 * @con_id: consumer name
987 *
988 * Lookup is first attempted using DT. If the device was not instantiated from
989 * a device tree, a PWM chip and a relative index is looked up via a table
990 * supplied by board setup code (see pwm_add_table()).
991 *
992 * Once a PWM chip has been found the specified PWM device will be requested
993 * and is ready to be used.
994 *
995 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
996 * error code on failure.
997 */
998struct pwm_device *pwm_get(struct device *dev, const char *con_id)
999{
1000 const char *dev_id = dev ? dev_name(dev) : NULL;
1001 struct pwm_device *pwm;
1002 struct pwm_chip *chip;
1003 struct device_link *dl;
1004 unsigned int best = 0;
1005 struct pwm_lookup *p, *chosen = NULL;
1006 unsigned int match;
1007 int err;
1008
1009 /* look up via DT first */
1010 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
1011 return of_pwm_get(dev, dev->of_node, con_id);
1012
1013 /* then lookup via ACPI */
1014 if (dev && is_acpi_node(dev->fwnode)) {
1015 pwm = acpi_pwm_get(dev->fwnode);
1016 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
1017 return pwm;
1018 }
1019
1020 /*
1021 * We look up the provider in the static table typically provided by
1022 * board setup code. We first try to lookup the consumer device by
1023 * name. If the consumer device was passed in as NULL or if no match
1024 * was found, we try to find the consumer by directly looking it up
1025 * by name.
1026 *
1027 * If a match is found, the provider PWM chip is looked up by name
1028 * and a PWM device is requested using the PWM device per-chip index.
1029 *
1030 * The lookup algorithm was shamelessly taken from the clock
1031 * framework:
1032 *
1033 * We do slightly fuzzy matching here:
1034 * An entry with a NULL ID is assumed to be a wildcard.
1035 * If an entry has a device ID, it must match
1036 * If an entry has a connection ID, it must match
1037 * Then we take the most specific entry - with the following order
1038 * of precedence: dev+con > dev only > con only.
1039 */
1040 mutex_lock(&pwm_lookup_lock);
1041
1042 list_for_each_entry(p, &pwm_lookup_list, list) {
1043 match = 0;
1044
1045 if (p->dev_id) {
1046 if (!dev_id || strcmp(p->dev_id, dev_id))
1047 continue;
1048
1049 match += 2;
1050 }
1051
1052 if (p->con_id) {
1053 if (!con_id || strcmp(p->con_id, con_id))
1054 continue;
1055
1056 match += 1;
1057 }
1058
1059 if (match > best) {
1060 chosen = p;
1061
1062 if (match != 3)
1063 best = match;
1064 else
1065 break;
1066 }
1067 }
1068
1069 mutex_unlock(&pwm_lookup_lock);
1070
1071 if (!chosen)
1072 return ERR_PTR(-ENODEV);
1073
1074 chip = pwmchip_find_by_name(chosen->provider);
1075
1076 /*
1077 * If the lookup entry specifies a module, load the module and retry
1078 * the PWM chip lookup. This can be used to work around driver load
1079 * ordering issues if driver's can't be made to properly support the
1080 * deferred probe mechanism.
1081 */
1082 if (!chip && chosen->module) {
1083 err = request_module(chosen->module);
1084 if (err == 0)
1085 chip = pwmchip_find_by_name(chosen->provider);
1086 }
1087
1088 if (!chip)
1089 return ERR_PTR(-EPROBE_DEFER);
1090
1091 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1092 if (IS_ERR(pwm))
1093 return pwm;
1094
1095 dl = pwm_device_link_add(dev, pwm);
1096 if (IS_ERR(dl)) {
1097 pwm_free(pwm);
1098 return ERR_CAST(dl);
1099 }
1100
1101 pwm->args.period = chosen->period;
1102 pwm->args.polarity = chosen->polarity;
1103
1104 return pwm;
1105}
1106EXPORT_SYMBOL_GPL(pwm_get);
1107
1108/**
1109 * pwm_put() - release a PWM device
1110 * @pwm: PWM device
1111 */
1112void pwm_put(struct pwm_device *pwm)
1113{
1114 if (!pwm)
1115 return;
1116
1117 mutex_lock(&pwm_lock);
1118
1119 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1120 pr_warn("PWM device already freed\n");
1121 goto out;
1122 }
1123
1124 if (pwm->chip->ops->free)
1125 pwm->chip->ops->free(pwm->chip, pwm);
1126
1127 pwm_set_chip_data(pwm, NULL);
1128 pwm->label = NULL;
1129
1130 module_put(pwm->chip->ops->owner);
1131out:
1132 mutex_unlock(&pwm_lock);
1133}
1134EXPORT_SYMBOL_GPL(pwm_put);
1135
1136static void devm_pwm_release(struct device *dev, void *res)
1137{
1138 pwm_put(*(struct pwm_device **)res);
1139}
1140
1141/**
1142 * devm_pwm_get() - resource managed pwm_get()
1143 * @dev: device for PWM consumer
1144 * @con_id: consumer name
1145 *
1146 * This function performs like pwm_get() but the acquired PWM device will
1147 * automatically be released on driver detach.
1148 *
1149 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1150 * error code on failure.
1151 */
1152struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1153{
1154 struct pwm_device **ptr, *pwm;
1155
1156 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1157 if (!ptr)
1158 return ERR_PTR(-ENOMEM);
1159
1160 pwm = pwm_get(dev, con_id);
1161 if (!IS_ERR(pwm)) {
1162 *ptr = pwm;
1163 devres_add(dev, ptr);
1164 } else {
1165 devres_free(ptr);
1166 }
1167
1168 return pwm;
1169}
1170EXPORT_SYMBOL_GPL(devm_pwm_get);
1171
1172/**
1173 * devm_of_pwm_get() - resource managed of_pwm_get()
1174 * @dev: device for PWM consumer
1175 * @np: device node to get the PWM from
1176 * @con_id: consumer name
1177 *
1178 * This function performs like of_pwm_get() but the acquired PWM device will
1179 * automatically be released on driver detach.
1180 *
1181 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1182 * error code on failure.
1183 */
1184struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1185 const char *con_id)
1186{
1187 struct pwm_device **ptr, *pwm;
1188
1189 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1190 if (!ptr)
1191 return ERR_PTR(-ENOMEM);
1192
1193 pwm = of_pwm_get(dev, np, con_id);
1194 if (!IS_ERR(pwm)) {
1195 *ptr = pwm;
1196 devres_add(dev, ptr);
1197 } else {
1198 devres_free(ptr);
1199 }
1200
1201 return pwm;
1202}
1203EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1204
1205/**
1206 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1207 * @dev: device for PWM consumer
1208 * @fwnode: firmware node to get the PWM from
1209 * @con_id: consumer name
1210 *
1211 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1212 * acpi_pwm_get() for a detailed description.
1213 *
1214 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1215 * error code on failure.
1216 */
1217struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1218 struct fwnode_handle *fwnode,
1219 const char *con_id)
1220{
1221 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1222
1223 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1224 if (!ptr)
1225 return ERR_PTR(-ENOMEM);
1226
1227 if (is_of_node(fwnode))
1228 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1229 else if (is_acpi_node(fwnode))
1230 pwm = acpi_pwm_get(fwnode);
1231
1232 if (!IS_ERR(pwm)) {
1233 *ptr = pwm;
1234 devres_add(dev, ptr);
1235 } else {
1236 devres_free(ptr);
1237 }
1238
1239 return pwm;
1240}
1241EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1242
1243static int devm_pwm_match(struct device *dev, void *res, void *data)
1244{
1245 struct pwm_device **p = res;
1246
1247 if (WARN_ON(!p || !*p))
1248 return 0;
1249
1250 return *p == data;
1251}
1252
1253/**
1254 * devm_pwm_put() - resource managed pwm_put()
1255 * @dev: device for PWM consumer
1256 * @pwm: PWM device
1257 *
1258 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1259 * function is usually not needed because devm-allocated resources are
1260 * automatically released on driver detach.
1261 */
1262void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1263{
1264 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1265}
1266EXPORT_SYMBOL_GPL(devm_pwm_put);
1267
1268#ifdef CONFIG_DEBUG_FS
1269static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1270{
1271 unsigned int i;
1272
1273 for (i = 0; i < chip->npwm; i++) {
1274 struct pwm_device *pwm = &chip->pwms[i];
1275 struct pwm_state state;
1276
1277 pwm_get_state(pwm, &state);
1278
1279 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1280
1281 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1282 seq_puts(s, " requested");
1283
1284 if (state.enabled)
1285 seq_puts(s, " enabled");
1286
1287 seq_printf(s, " period: %llu ns", state.period);
1288 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1289 seq_printf(s, " polarity: %s",
1290 state.polarity ? "inverse" : "normal");
1291
1292 seq_puts(s, "\n");
1293 }
1294}
1295
1296static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1297{
1298 mutex_lock(&pwm_lock);
1299 s->private = "";
1300
1301 return seq_list_start(&pwm_chips, *pos);
1302}
1303
1304static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1305{
1306 s->private = "\n";
1307
1308 return seq_list_next(v, &pwm_chips, pos);
1309}
1310
1311static void pwm_seq_stop(struct seq_file *s, void *v)
1312{
1313 mutex_unlock(&pwm_lock);
1314}
1315
1316static int pwm_seq_show(struct seq_file *s, void *v)
1317{
1318 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1319
1320 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1321 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1322 dev_name(chip->dev), chip->npwm,
1323 (chip->npwm != 1) ? "s" : "");
1324
1325 pwm_dbg_show(chip, s);
1326
1327 return 0;
1328}
1329
1330static const struct seq_operations pwm_seq_ops = {
1331 .start = pwm_seq_start,
1332 .next = pwm_seq_next,
1333 .stop = pwm_seq_stop,
1334 .show = pwm_seq_show,
1335};
1336
1337static int pwm_seq_open(struct inode *inode, struct file *file)
1338{
1339 return seq_open(file, &pwm_seq_ops);
1340}
1341
1342static const struct file_operations pwm_debugfs_ops = {
1343 .owner = THIS_MODULE,
1344 .open = pwm_seq_open,
1345 .read = seq_read,
1346 .llseek = seq_lseek,
1347 .release = seq_release,
1348};
1349
1350static int __init pwm_debugfs_init(void)
1351{
1352 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1353 &pwm_debugfs_ops);
1354
1355 return 0;
1356}
1357subsys_initcall(pwm_debugfs_init);
1358#endif /* CONFIG_DEBUG_FS */