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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 MAX_PWMS 1024
24
25static DEFINE_MUTEX(pwm_lookup_lock);
26static LIST_HEAD(pwm_lookup_list);
27static DEFINE_MUTEX(pwm_lock);
28static LIST_HEAD(pwm_chips);
29static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
30static RADIX_TREE(pwm_tree, GFP_KERNEL);
31
32static struct pwm_device *pwm_to_device(unsigned int pwm)
33{
34 return radix_tree_lookup(&pwm_tree, pwm);
35}
36
37static int alloc_pwms(int pwm, unsigned int count)
38{
39 unsigned int from = 0;
40 unsigned int start;
41
42 if (pwm >= MAX_PWMS)
43 return -EINVAL;
44
45 if (pwm >= 0)
46 from = pwm;
47
48 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
49 count, 0);
50
51 if (pwm >= 0 && start != pwm)
52 return -EEXIST;
53
54 if (start + count > MAX_PWMS)
55 return -ENOSPC;
56
57 return start;
58}
59
60static void free_pwms(struct pwm_chip *chip)
61{
62 unsigned int i;
63
64 for (i = 0; i < chip->npwm; i++) {
65 struct pwm_device *pwm = &chip->pwms[i];
66
67 radix_tree_delete(&pwm_tree, pwm->pwm);
68 }
69
70 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
71
72 kfree(chip->pwms);
73 chip->pwms = NULL;
74}
75
76static struct pwm_chip *pwmchip_find_by_name(const char *name)
77{
78 struct pwm_chip *chip;
79
80 if (!name)
81 return NULL;
82
83 mutex_lock(&pwm_lock);
84
85 list_for_each_entry(chip, &pwm_chips, list) {
86 const char *chip_name = dev_name(chip->dev);
87
88 if (chip_name && strcmp(chip_name, name) == 0) {
89 mutex_unlock(&pwm_lock);
90 return chip;
91 }
92 }
93
94 mutex_unlock(&pwm_lock);
95
96 return NULL;
97}
98
99static int pwm_device_request(struct pwm_device *pwm, const char *label)
100{
101 int err;
102
103 if (test_bit(PWMF_REQUESTED, &pwm->flags))
104 return -EBUSY;
105
106 if (!try_module_get(pwm->chip->ops->owner))
107 return -ENODEV;
108
109 if (pwm->chip->ops->request) {
110 err = pwm->chip->ops->request(pwm->chip, pwm);
111 if (err) {
112 module_put(pwm->chip->ops->owner);
113 return err;
114 }
115 }
116
117 set_bit(PWMF_REQUESTED, &pwm->flags);
118 pwm->label = label;
119
120 return 0;
121}
122
123struct pwm_device *
124of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
125{
126 struct pwm_device *pwm;
127
128 /* check, whether the driver supports a third cell for flags */
129 if (pc->of_pwm_n_cells < 3)
130 return ERR_PTR(-EINVAL);
131
132 /* flags in the third cell are optional */
133 if (args->args_count < 2)
134 return ERR_PTR(-EINVAL);
135
136 if (args->args[0] >= pc->npwm)
137 return ERR_PTR(-EINVAL);
138
139 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
140 if (IS_ERR(pwm))
141 return pwm;
142
143 pwm->args.period = args->args[1];
144 pwm->args.polarity = PWM_POLARITY_NORMAL;
145
146 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
147 pwm->args.polarity = PWM_POLARITY_INVERSED;
148
149 return pwm;
150}
151EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
152
153static struct pwm_device *
154of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
155{
156 struct pwm_device *pwm;
157
158 /* sanity check driver support */
159 if (pc->of_pwm_n_cells < 2)
160 return ERR_PTR(-EINVAL);
161
162 /* all cells are required */
163 if (args->args_count != pc->of_pwm_n_cells)
164 return ERR_PTR(-EINVAL);
165
166 if (args->args[0] >= pc->npwm)
167 return ERR_PTR(-EINVAL);
168
169 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
170 if (IS_ERR(pwm))
171 return pwm;
172
173 pwm->args.period = args->args[1];
174
175 return pwm;
176}
177
178static void of_pwmchip_add(struct pwm_chip *chip)
179{
180 if (!chip->dev || !chip->dev->of_node)
181 return;
182
183 if (!chip->of_xlate) {
184 chip->of_xlate = of_pwm_simple_xlate;
185 chip->of_pwm_n_cells = 2;
186 }
187
188 of_node_get(chip->dev->of_node);
189}
190
191static void of_pwmchip_remove(struct pwm_chip *chip)
192{
193 if (chip->dev)
194 of_node_put(chip->dev->of_node);
195}
196
197/**
198 * pwm_set_chip_data() - set private chip data for a PWM
199 * @pwm: PWM device
200 * @data: pointer to chip-specific data
201 *
202 * Returns: 0 on success or a negative error code on failure.
203 */
204int pwm_set_chip_data(struct pwm_device *pwm, void *data)
205{
206 if (!pwm)
207 return -EINVAL;
208
209 pwm->chip_data = data;
210
211 return 0;
212}
213EXPORT_SYMBOL_GPL(pwm_set_chip_data);
214
215/**
216 * pwm_get_chip_data() - get private chip data for a PWM
217 * @pwm: PWM device
218 *
219 * Returns: A pointer to the chip-private data for the PWM device.
220 */
221void *pwm_get_chip_data(struct pwm_device *pwm)
222{
223 return pwm ? pwm->chip_data : NULL;
224}
225EXPORT_SYMBOL_GPL(pwm_get_chip_data);
226
227static bool pwm_ops_check(const struct pwm_ops *ops)
228{
229 /* driver supports legacy, non-atomic operation */
230 if (ops->config && ops->enable && ops->disable)
231 return true;
232
233 /* driver supports atomic operation */
234 if (ops->apply)
235 return true;
236
237 return false;
238}
239
240/**
241 * pwmchip_add_with_polarity() - register a new PWM chip
242 * @chip: the PWM chip to add
243 * @polarity: initial polarity of PWM channels
244 *
245 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
246 * will be used. The initial polarity for all channels is specified by the
247 * @polarity parameter.
248 *
249 * Returns: 0 on success or a negative error code on failure.
250 */
251int pwmchip_add_with_polarity(struct pwm_chip *chip,
252 enum pwm_polarity polarity)
253{
254 struct pwm_device *pwm;
255 unsigned int i;
256 int ret;
257
258 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
259 return -EINVAL;
260
261 if (!pwm_ops_check(chip->ops))
262 return -EINVAL;
263
264 mutex_lock(&pwm_lock);
265
266 ret = alloc_pwms(chip->base, chip->npwm);
267 if (ret < 0)
268 goto out;
269
270 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
271 if (!chip->pwms) {
272 ret = -ENOMEM;
273 goto out;
274 }
275
276 chip->base = ret;
277
278 for (i = 0; i < chip->npwm; i++) {
279 pwm = &chip->pwms[i];
280
281 pwm->chip = chip;
282 pwm->pwm = chip->base + i;
283 pwm->hwpwm = i;
284 pwm->state.polarity = polarity;
285
286 if (chip->ops->get_state)
287 chip->ops->get_state(chip, pwm, &pwm->state);
288
289 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
290 }
291
292 bitmap_set(allocated_pwms, chip->base, chip->npwm);
293
294 INIT_LIST_HEAD(&chip->list);
295 list_add(&chip->list, &pwm_chips);
296
297 ret = 0;
298
299 if (IS_ENABLED(CONFIG_OF))
300 of_pwmchip_add(chip);
301
302out:
303 mutex_unlock(&pwm_lock);
304
305 if (!ret)
306 pwmchip_sysfs_export(chip);
307
308 return ret;
309}
310EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
311
312/**
313 * pwmchip_add() - register a new PWM chip
314 * @chip: the PWM chip to add
315 *
316 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
317 * will be used. The initial polarity for all channels is normal.
318 *
319 * Returns: 0 on success or a negative error code on failure.
320 */
321int pwmchip_add(struct pwm_chip *chip)
322{
323 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
324}
325EXPORT_SYMBOL_GPL(pwmchip_add);
326
327/**
328 * pwmchip_remove() - remove a PWM chip
329 * @chip: the PWM chip to remove
330 *
331 * Removes a PWM chip. This function may return busy if the PWM chip provides
332 * a PWM device that is still requested.
333 *
334 * Returns: 0 on success or a negative error code on failure.
335 */
336int pwmchip_remove(struct pwm_chip *chip)
337{
338 unsigned int i;
339 int ret = 0;
340
341 pwmchip_sysfs_unexport(chip);
342
343 mutex_lock(&pwm_lock);
344
345 for (i = 0; i < chip->npwm; i++) {
346 struct pwm_device *pwm = &chip->pwms[i];
347
348 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
349 ret = -EBUSY;
350 goto out;
351 }
352 }
353
354 list_del_init(&chip->list);
355
356 if (IS_ENABLED(CONFIG_OF))
357 of_pwmchip_remove(chip);
358
359 free_pwms(chip);
360
361out:
362 mutex_unlock(&pwm_lock);
363 return ret;
364}
365EXPORT_SYMBOL_GPL(pwmchip_remove);
366
367/**
368 * pwm_request() - request a PWM device
369 * @pwm: global PWM device index
370 * @label: PWM device label
371 *
372 * This function is deprecated, use pwm_get() instead.
373 *
374 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
375 * failure.
376 */
377struct pwm_device *pwm_request(int pwm, const char *label)
378{
379 struct pwm_device *dev;
380 int err;
381
382 if (pwm < 0 || pwm >= MAX_PWMS)
383 return ERR_PTR(-EINVAL);
384
385 mutex_lock(&pwm_lock);
386
387 dev = pwm_to_device(pwm);
388 if (!dev) {
389 dev = ERR_PTR(-EPROBE_DEFER);
390 goto out;
391 }
392
393 err = pwm_device_request(dev, label);
394 if (err < 0)
395 dev = ERR_PTR(err);
396
397out:
398 mutex_unlock(&pwm_lock);
399
400 return dev;
401}
402EXPORT_SYMBOL_GPL(pwm_request);
403
404/**
405 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
406 * @chip: PWM chip
407 * @index: per-chip index of the PWM to request
408 * @label: a literal description string of this PWM
409 *
410 * Returns: A pointer to the PWM device at the given index of the given PWM
411 * chip. A negative error code is returned if the index is not valid for the
412 * specified PWM chip or if the PWM device cannot be requested.
413 */
414struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
415 unsigned int index,
416 const char *label)
417{
418 struct pwm_device *pwm;
419 int err;
420
421 if (!chip || index >= chip->npwm)
422 return ERR_PTR(-EINVAL);
423
424 mutex_lock(&pwm_lock);
425 pwm = &chip->pwms[index];
426
427 err = pwm_device_request(pwm, label);
428 if (err < 0)
429 pwm = ERR_PTR(err);
430
431 mutex_unlock(&pwm_lock);
432 return pwm;
433}
434EXPORT_SYMBOL_GPL(pwm_request_from_chip);
435
436/**
437 * pwm_free() - free a PWM device
438 * @pwm: PWM device
439 *
440 * This function is deprecated, use pwm_put() instead.
441 */
442void pwm_free(struct pwm_device *pwm)
443{
444 pwm_put(pwm);
445}
446EXPORT_SYMBOL_GPL(pwm_free);
447
448/**
449 * pwm_apply_state() - atomically apply a new state to a PWM device
450 * @pwm: PWM device
451 * @state: new state to apply
452 */
453int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
454{
455 struct pwm_chip *chip;
456 int err;
457
458 if (!pwm || !state || !state->period ||
459 state->duty_cycle > state->period)
460 return -EINVAL;
461
462 chip = pwm->chip;
463
464 if (state->period == pwm->state.period &&
465 state->duty_cycle == pwm->state.duty_cycle &&
466 state->polarity == pwm->state.polarity &&
467 state->enabled == pwm->state.enabled)
468 return 0;
469
470 if (chip->ops->apply) {
471 err = chip->ops->apply(chip, pwm, state);
472 if (err)
473 return err;
474
475 pwm->state = *state;
476 } else {
477 /*
478 * FIXME: restore the initial state in case of error.
479 */
480 if (state->polarity != pwm->state.polarity) {
481 if (!chip->ops->set_polarity)
482 return -ENOTSUPP;
483
484 /*
485 * Changing the polarity of a running PWM is
486 * only allowed when the PWM driver implements
487 * ->apply().
488 */
489 if (pwm->state.enabled) {
490 chip->ops->disable(chip, pwm);
491 pwm->state.enabled = false;
492 }
493
494 err = chip->ops->set_polarity(chip, pwm,
495 state->polarity);
496 if (err)
497 return err;
498
499 pwm->state.polarity = state->polarity;
500 }
501
502 if (state->period != pwm->state.period ||
503 state->duty_cycle != pwm->state.duty_cycle) {
504 err = chip->ops->config(pwm->chip, pwm,
505 state->duty_cycle,
506 state->period);
507 if (err)
508 return err;
509
510 pwm->state.duty_cycle = state->duty_cycle;
511 pwm->state.period = state->period;
512 }
513
514 if (state->enabled != pwm->state.enabled) {
515 if (state->enabled) {
516 err = chip->ops->enable(chip, pwm);
517 if (err)
518 return err;
519 } else {
520 chip->ops->disable(chip, pwm);
521 }
522
523 pwm->state.enabled = state->enabled;
524 }
525 }
526
527 return 0;
528}
529EXPORT_SYMBOL_GPL(pwm_apply_state);
530
531/**
532 * pwm_capture() - capture and report a PWM signal
533 * @pwm: PWM device
534 * @result: structure to fill with capture result
535 * @timeout: time to wait, in milliseconds, before giving up on capture
536 *
537 * Returns: 0 on success or a negative error code on failure.
538 */
539int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
540 unsigned long timeout)
541{
542 int err;
543
544 if (!pwm || !pwm->chip->ops)
545 return -EINVAL;
546
547 if (!pwm->chip->ops->capture)
548 return -ENOSYS;
549
550 mutex_lock(&pwm_lock);
551 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
552 mutex_unlock(&pwm_lock);
553
554 return err;
555}
556EXPORT_SYMBOL_GPL(pwm_capture);
557
558/**
559 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
560 * @pwm: PWM device
561 *
562 * This function will adjust the PWM config to the PWM arguments provided
563 * by the DT or PWM lookup table. This is particularly useful to adapt
564 * the bootloader config to the Linux one.
565 */
566int pwm_adjust_config(struct pwm_device *pwm)
567{
568 struct pwm_state state;
569 struct pwm_args pargs;
570
571 pwm_get_args(pwm, &pargs);
572 pwm_get_state(pwm, &state);
573
574 /*
575 * If the current period is zero it means that either the PWM driver
576 * does not support initial state retrieval or the PWM has not yet
577 * been configured.
578 *
579 * In either case, we setup the new period and polarity, and assign a
580 * duty cycle of 0.
581 */
582 if (!state.period) {
583 state.duty_cycle = 0;
584 state.period = pargs.period;
585 state.polarity = pargs.polarity;
586
587 return pwm_apply_state(pwm, &state);
588 }
589
590 /*
591 * Adjust the PWM duty cycle/period based on the period value provided
592 * in PWM args.
593 */
594 if (pargs.period != state.period) {
595 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
596
597 do_div(dutycycle, state.period);
598 state.duty_cycle = dutycycle;
599 state.period = pargs.period;
600 }
601
602 /*
603 * If the polarity changed, we should also change the duty cycle.
604 */
605 if (pargs.polarity != state.polarity) {
606 state.polarity = pargs.polarity;
607 state.duty_cycle = state.period - state.duty_cycle;
608 }
609
610 return pwm_apply_state(pwm, &state);
611}
612EXPORT_SYMBOL_GPL(pwm_adjust_config);
613
614static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
615{
616 struct pwm_chip *chip;
617
618 mutex_lock(&pwm_lock);
619
620 list_for_each_entry(chip, &pwm_chips, list)
621 if (chip->dev && chip->dev->of_node == np) {
622 mutex_unlock(&pwm_lock);
623 return chip;
624 }
625
626 mutex_unlock(&pwm_lock);
627
628 return ERR_PTR(-EPROBE_DEFER);
629}
630
631static struct device_link *pwm_device_link_add(struct device *dev,
632 struct pwm_device *pwm)
633{
634 struct device_link *dl;
635
636 if (!dev) {
637 /*
638 * No device for the PWM consumer has been provided. It may
639 * impact the PM sequence ordering: the PWM supplier may get
640 * suspended before the consumer.
641 */
642 dev_warn(pwm->chip->dev,
643 "No consumer device specified to create a link to\n");
644 return NULL;
645 }
646
647 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
648 if (!dl) {
649 dev_err(dev, "failed to create device link to %s\n",
650 dev_name(pwm->chip->dev));
651 return ERR_PTR(-EINVAL);
652 }
653
654 return dl;
655}
656
657/**
658 * of_pwm_get() - request a PWM via the PWM framework
659 * @dev: device for PWM consumer
660 * @np: device node to get the PWM from
661 * @con_id: consumer name
662 *
663 * Returns the PWM device parsed from the phandle and index specified in the
664 * "pwms" property of a device tree node or a negative error-code on failure.
665 * Values parsed from the device tree are stored in the returned PWM device
666 * object.
667 *
668 * If con_id is NULL, the first PWM device listed in the "pwms" property will
669 * be requested. Otherwise the "pwm-names" property is used to do a reverse
670 * lookup of the PWM index. This also means that the "pwm-names" property
671 * becomes mandatory for devices that look up the PWM device via the con_id
672 * parameter.
673 *
674 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
675 * error code on failure.
676 */
677struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
678 const char *con_id)
679{
680 struct pwm_device *pwm = NULL;
681 struct of_phandle_args args;
682 struct device_link *dl;
683 struct pwm_chip *pc;
684 int index = 0;
685 int err;
686
687 if (con_id) {
688 index = of_property_match_string(np, "pwm-names", con_id);
689 if (index < 0)
690 return ERR_PTR(index);
691 }
692
693 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
694 &args);
695 if (err) {
696 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
697 return ERR_PTR(err);
698 }
699
700 pc = of_node_to_pwmchip(args.np);
701 if (IS_ERR(pc)) {
702 if (PTR_ERR(pc) != -EPROBE_DEFER)
703 pr_err("%s(): PWM chip not found\n", __func__);
704
705 pwm = ERR_CAST(pc);
706 goto put;
707 }
708
709 pwm = pc->of_xlate(pc, &args);
710 if (IS_ERR(pwm))
711 goto put;
712
713 dl = pwm_device_link_add(dev, pwm);
714 if (IS_ERR(dl)) {
715 /* of_xlate ended up calling pwm_request_from_chip() */
716 pwm_free(pwm);
717 pwm = ERR_CAST(dl);
718 goto put;
719 }
720
721 /*
722 * If a consumer name was not given, try to look it up from the
723 * "pwm-names" property if it exists. Otherwise use the name of
724 * the user device node.
725 */
726 if (!con_id) {
727 err = of_property_read_string_index(np, "pwm-names", index,
728 &con_id);
729 if (err < 0)
730 con_id = np->name;
731 }
732
733 pwm->label = con_id;
734
735put:
736 of_node_put(args.np);
737
738 return pwm;
739}
740EXPORT_SYMBOL_GPL(of_pwm_get);
741
742#if IS_ENABLED(CONFIG_ACPI)
743static struct pwm_chip *device_to_pwmchip(struct device *dev)
744{
745 struct pwm_chip *chip;
746
747 mutex_lock(&pwm_lock);
748
749 list_for_each_entry(chip, &pwm_chips, list) {
750 struct acpi_device *adev = ACPI_COMPANION(chip->dev);
751
752 if ((chip->dev == dev) || (adev && &adev->dev == dev)) {
753 mutex_unlock(&pwm_lock);
754 return chip;
755 }
756 }
757
758 mutex_unlock(&pwm_lock);
759
760 return ERR_PTR(-EPROBE_DEFER);
761}
762#endif
763
764/**
765 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
766 * @fwnode: firmware node to get the "pwm" property from
767 *
768 * Returns the PWM device parsed from the fwnode and index specified in the
769 * "pwms" property or a negative error-code on failure.
770 * Values parsed from the device tree are stored in the returned PWM device
771 * object.
772 *
773 * This is analogous to of_pwm_get() except con_id is not yet supported.
774 * ACPI entries must look like
775 * Package () {"pwms", Package ()
776 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
777 *
778 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
779 * error code on failure.
780 */
781static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode)
782{
783 struct pwm_device *pwm = ERR_PTR(-ENODEV);
784#if IS_ENABLED(CONFIG_ACPI)
785 struct fwnode_reference_args args;
786 struct acpi_device *acpi;
787 struct pwm_chip *chip;
788 int ret;
789
790 memset(&args, 0, sizeof(args));
791
792 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
793 if (ret < 0)
794 return ERR_PTR(ret);
795
796 acpi = to_acpi_device_node(args.fwnode);
797 if (!acpi)
798 return ERR_PTR(-EINVAL);
799
800 if (args.nargs < 2)
801 return ERR_PTR(-EPROTO);
802
803 chip = device_to_pwmchip(&acpi->dev);
804 if (IS_ERR(chip))
805 return ERR_CAST(chip);
806
807 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
808 if (IS_ERR(pwm))
809 return pwm;
810
811 pwm->args.period = args.args[1];
812 pwm->args.polarity = PWM_POLARITY_NORMAL;
813
814 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
815 pwm->args.polarity = PWM_POLARITY_INVERSED;
816#endif
817
818 return pwm;
819}
820
821/**
822 * pwm_add_table() - register PWM device consumers
823 * @table: array of consumers to register
824 * @num: number of consumers in table
825 */
826void pwm_add_table(struct pwm_lookup *table, size_t num)
827{
828 mutex_lock(&pwm_lookup_lock);
829
830 while (num--) {
831 list_add_tail(&table->list, &pwm_lookup_list);
832 table++;
833 }
834
835 mutex_unlock(&pwm_lookup_lock);
836}
837
838/**
839 * pwm_remove_table() - unregister PWM device consumers
840 * @table: array of consumers to unregister
841 * @num: number of consumers in table
842 */
843void pwm_remove_table(struct pwm_lookup *table, size_t num)
844{
845 mutex_lock(&pwm_lookup_lock);
846
847 while (num--) {
848 list_del(&table->list);
849 table++;
850 }
851
852 mutex_unlock(&pwm_lookup_lock);
853}
854
855/**
856 * pwm_get() - look up and request a PWM device
857 * @dev: device for PWM consumer
858 * @con_id: consumer name
859 *
860 * Lookup is first attempted using DT. If the device was not instantiated from
861 * a device tree, a PWM chip and a relative index is looked up via a table
862 * supplied by board setup code (see pwm_add_table()).
863 *
864 * Once a PWM chip has been found the specified PWM device will be requested
865 * and is ready to be used.
866 *
867 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
868 * error code on failure.
869 */
870struct pwm_device *pwm_get(struct device *dev, const char *con_id)
871{
872 const char *dev_id = dev ? dev_name(dev) : NULL;
873 struct pwm_device *pwm;
874 struct pwm_chip *chip;
875 struct device_link *dl;
876 unsigned int best = 0;
877 struct pwm_lookup *p, *chosen = NULL;
878 unsigned int match;
879 int err;
880
881 /* look up via DT first */
882 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
883 return of_pwm_get(dev, dev->of_node, con_id);
884
885 /* then lookup via ACPI */
886 if (dev && is_acpi_node(dev->fwnode)) {
887 pwm = acpi_pwm_get(dev->fwnode);
888 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
889 return pwm;
890 }
891
892 /*
893 * We look up the provider in the static table typically provided by
894 * board setup code. We first try to lookup the consumer device by
895 * name. If the consumer device was passed in as NULL or if no match
896 * was found, we try to find the consumer by directly looking it up
897 * by name.
898 *
899 * If a match is found, the provider PWM chip is looked up by name
900 * and a PWM device is requested using the PWM device per-chip index.
901 *
902 * The lookup algorithm was shamelessly taken from the clock
903 * framework:
904 *
905 * We do slightly fuzzy matching here:
906 * An entry with a NULL ID is assumed to be a wildcard.
907 * If an entry has a device ID, it must match
908 * If an entry has a connection ID, it must match
909 * Then we take the most specific entry - with the following order
910 * of precedence: dev+con > dev only > con only.
911 */
912 mutex_lock(&pwm_lookup_lock);
913
914 list_for_each_entry(p, &pwm_lookup_list, list) {
915 match = 0;
916
917 if (p->dev_id) {
918 if (!dev_id || strcmp(p->dev_id, dev_id))
919 continue;
920
921 match += 2;
922 }
923
924 if (p->con_id) {
925 if (!con_id || strcmp(p->con_id, con_id))
926 continue;
927
928 match += 1;
929 }
930
931 if (match > best) {
932 chosen = p;
933
934 if (match != 3)
935 best = match;
936 else
937 break;
938 }
939 }
940
941 mutex_unlock(&pwm_lookup_lock);
942
943 if (!chosen)
944 return ERR_PTR(-ENODEV);
945
946 chip = pwmchip_find_by_name(chosen->provider);
947
948 /*
949 * If the lookup entry specifies a module, load the module and retry
950 * the PWM chip lookup. This can be used to work around driver load
951 * ordering issues if driver's can't be made to properly support the
952 * deferred probe mechanism.
953 */
954 if (!chip && chosen->module) {
955 err = request_module(chosen->module);
956 if (err == 0)
957 chip = pwmchip_find_by_name(chosen->provider);
958 }
959
960 if (!chip)
961 return ERR_PTR(-EPROBE_DEFER);
962
963 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
964 if (IS_ERR(pwm))
965 return pwm;
966
967 dl = pwm_device_link_add(dev, pwm);
968 if (IS_ERR(dl)) {
969 pwm_free(pwm);
970 return ERR_CAST(dl);
971 }
972
973 pwm->args.period = chosen->period;
974 pwm->args.polarity = chosen->polarity;
975
976 return pwm;
977}
978EXPORT_SYMBOL_GPL(pwm_get);
979
980/**
981 * pwm_put() - release a PWM device
982 * @pwm: PWM device
983 */
984void pwm_put(struct pwm_device *pwm)
985{
986 if (!pwm)
987 return;
988
989 mutex_lock(&pwm_lock);
990
991 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
992 pr_warn("PWM device already freed\n");
993 goto out;
994 }
995
996 if (pwm->chip->ops->free)
997 pwm->chip->ops->free(pwm->chip, pwm);
998
999 pwm_set_chip_data(pwm, NULL);
1000 pwm->label = NULL;
1001
1002 module_put(pwm->chip->ops->owner);
1003out:
1004 mutex_unlock(&pwm_lock);
1005}
1006EXPORT_SYMBOL_GPL(pwm_put);
1007
1008static void devm_pwm_release(struct device *dev, void *res)
1009{
1010 pwm_put(*(struct pwm_device **)res);
1011}
1012
1013/**
1014 * devm_pwm_get() - resource managed pwm_get()
1015 * @dev: device for PWM consumer
1016 * @con_id: consumer name
1017 *
1018 * This function performs like pwm_get() but the acquired PWM device will
1019 * automatically be released on driver detach.
1020 *
1021 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1022 * error code on failure.
1023 */
1024struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1025{
1026 struct pwm_device **ptr, *pwm;
1027
1028 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1029 if (!ptr)
1030 return ERR_PTR(-ENOMEM);
1031
1032 pwm = pwm_get(dev, con_id);
1033 if (!IS_ERR(pwm)) {
1034 *ptr = pwm;
1035 devres_add(dev, ptr);
1036 } else {
1037 devres_free(ptr);
1038 }
1039
1040 return pwm;
1041}
1042EXPORT_SYMBOL_GPL(devm_pwm_get);
1043
1044/**
1045 * devm_of_pwm_get() - resource managed of_pwm_get()
1046 * @dev: device for PWM consumer
1047 * @np: device node to get the PWM from
1048 * @con_id: consumer name
1049 *
1050 * This function performs like of_pwm_get() but the acquired PWM device will
1051 * automatically be released on driver detach.
1052 *
1053 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1054 * error code on failure.
1055 */
1056struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
1057 const char *con_id)
1058{
1059 struct pwm_device **ptr, *pwm;
1060
1061 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1062 if (!ptr)
1063 return ERR_PTR(-ENOMEM);
1064
1065 pwm = of_pwm_get(dev, np, con_id);
1066 if (!IS_ERR(pwm)) {
1067 *ptr = pwm;
1068 devres_add(dev, ptr);
1069 } else {
1070 devres_free(ptr);
1071 }
1072
1073 return pwm;
1074}
1075EXPORT_SYMBOL_GPL(devm_of_pwm_get);
1076
1077/**
1078 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1079 * @dev: device for PWM consumer
1080 * @fwnode: firmware node to get the PWM from
1081 * @con_id: consumer name
1082 *
1083 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1084 * acpi_pwm_get() for a detailed description.
1085 *
1086 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1087 * error code on failure.
1088 */
1089struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1090 struct fwnode_handle *fwnode,
1091 const char *con_id)
1092{
1093 struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV);
1094
1095 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
1096 if (!ptr)
1097 return ERR_PTR(-ENOMEM);
1098
1099 if (is_of_node(fwnode))
1100 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1101 else if (is_acpi_node(fwnode))
1102 pwm = acpi_pwm_get(fwnode);
1103
1104 if (!IS_ERR(pwm)) {
1105 *ptr = pwm;
1106 devres_add(dev, ptr);
1107 } else {
1108 devres_free(ptr);
1109 }
1110
1111 return pwm;
1112}
1113EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1114
1115static int devm_pwm_match(struct device *dev, void *res, void *data)
1116{
1117 struct pwm_device **p = res;
1118
1119 if (WARN_ON(!p || !*p))
1120 return 0;
1121
1122 return *p == data;
1123}
1124
1125/**
1126 * devm_pwm_put() - resource managed pwm_put()
1127 * @dev: device for PWM consumer
1128 * @pwm: PWM device
1129 *
1130 * Release a PWM previously allocated using devm_pwm_get(). Calling this
1131 * function is usually not needed because devm-allocated resources are
1132 * automatically released on driver detach.
1133 */
1134void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
1135{
1136 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
1137}
1138EXPORT_SYMBOL_GPL(devm_pwm_put);
1139
1140#ifdef CONFIG_DEBUG_FS
1141static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1142{
1143 unsigned int i;
1144
1145 for (i = 0; i < chip->npwm; i++) {
1146 struct pwm_device *pwm = &chip->pwms[i];
1147 struct pwm_state state;
1148
1149 pwm_get_state(pwm, &state);
1150
1151 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1152
1153 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1154 seq_puts(s, " requested");
1155
1156 if (state.enabled)
1157 seq_puts(s, " enabled");
1158
1159 seq_printf(s, " period: %u ns", state.period);
1160 seq_printf(s, " duty: %u ns", state.duty_cycle);
1161 seq_printf(s, " polarity: %s",
1162 state.polarity ? "inverse" : "normal");
1163
1164 seq_puts(s, "\n");
1165 }
1166}
1167
1168static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1169{
1170 mutex_lock(&pwm_lock);
1171 s->private = "";
1172
1173 return seq_list_start(&pwm_chips, *pos);
1174}
1175
1176static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1177{
1178 s->private = "\n";
1179
1180 return seq_list_next(v, &pwm_chips, pos);
1181}
1182
1183static void pwm_seq_stop(struct seq_file *s, void *v)
1184{
1185 mutex_unlock(&pwm_lock);
1186}
1187
1188static int pwm_seq_show(struct seq_file *s, void *v)
1189{
1190 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1191
1192 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1193 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1194 dev_name(chip->dev), chip->npwm,
1195 (chip->npwm != 1) ? "s" : "");
1196
1197 pwm_dbg_show(chip, s);
1198
1199 return 0;
1200}
1201
1202static const struct seq_operations pwm_seq_ops = {
1203 .start = pwm_seq_start,
1204 .next = pwm_seq_next,
1205 .stop = pwm_seq_stop,
1206 .show = pwm_seq_show,
1207};
1208
1209static int pwm_seq_open(struct inode *inode, struct file *file)
1210{
1211 return seq_open(file, &pwm_seq_ops);
1212}
1213
1214static const struct file_operations pwm_debugfs_ops = {
1215 .owner = THIS_MODULE,
1216 .open = pwm_seq_open,
1217 .read = seq_read,
1218 .llseek = seq_lseek,
1219 .release = seq_release,
1220};
1221
1222static int __init pwm_debugfs_init(void)
1223{
1224 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
1225 &pwm_debugfs_ops);
1226
1227 return 0;
1228}
1229subsys_initcall(pwm_debugfs_init);
1230#endif /* CONFIG_DEBUG_FS */