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
37 static DEFINE_MUTEX(pwm_lookup_lock);
38 static LIST_HEAD(pwm_lookup_list);
39 static DEFINE_MUTEX(pwm_lock);
40 static LIST_HEAD(pwm_chips);
41 static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42 static RADIX_TREE(pwm_tree, GFP_KERNEL);
43
pwm_to_device(unsigned int pwm)44 static struct pwm_device *pwm_to_device(unsigned int pwm)
45 {
46 return radix_tree_lookup(&pwm_tree, pwm);
47 }
48
alloc_pwms(int pwm,unsigned int count)49 static 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
free_pwms(struct pwm_chip * chip)72 static 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
pwmchip_find_by_name(const char * name)87 static 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
pwm_device_request(struct pwm_device * pwm,const char * label)110 static 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
134 struct pwm_device *
of_pwm_xlate_with_flags(struct pwm_chip * pc,const struct of_phandle_args * args)135 of_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 }
158 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
159
160 static struct pwm_device *
of_pwm_simple_xlate(struct pwm_chip * pc,const struct of_phandle_args * args)161 of_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
of_pwmchip_add(struct pwm_chip * chip)180 static 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
of_pwmchip_remove(struct pwm_chip * chip)193 static void of_pwmchip_remove(struct pwm_chip *chip)
194 {
195 if (chip->dev && chip->dev->of_node)
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 */
pwm_set_chip_data(struct pwm_device * pwm,void * data)204 int 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 }
213 EXPORT_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 */
pwm_get_chip_data(struct pwm_device * pwm)219 void *pwm_get_chip_data(struct pwm_device *pwm)
220 {
221 return pwm ? pwm->chip_data : NULL;
222 }
223 EXPORT_SYMBOL_GPL(pwm_get_chip_data);
224
225 /**
226 * pwmchip_add() - register a new PWM chip
227 * @chip: the PWM chip to add
228 *
229 * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base
230 * will be used.
231 */
pwmchip_add(struct pwm_chip * chip)232 int pwmchip_add(struct pwm_chip *chip)
233 {
234 struct pwm_device *pwm;
235 unsigned int i;
236 int ret;
237
238 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
239 !chip->ops->enable || !chip->ops->disable || !chip->npwm)
240 return -EINVAL;
241
242 mutex_lock(&pwm_lock);
243
244 ret = alloc_pwms(chip->base, chip->npwm);
245 if (ret < 0)
246 goto out;
247
248 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
249 if (!chip->pwms) {
250 ret = -ENOMEM;
251 goto out;
252 }
253
254 chip->base = ret;
255
256 for (i = 0; i < chip->npwm; i++) {
257 pwm = &chip->pwms[i];
258
259 pwm->chip = chip;
260 pwm->pwm = chip->base + i;
261 pwm->hwpwm = i;
262
263 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
264 }
265
266 bitmap_set(allocated_pwms, chip->base, chip->npwm);
267
268 INIT_LIST_HEAD(&chip->list);
269 list_add(&chip->list, &pwm_chips);
270
271 ret = 0;
272
273 if (IS_ENABLED(CONFIG_OF))
274 of_pwmchip_add(chip);
275
276 pwmchip_sysfs_export(chip);
277
278 out:
279 mutex_unlock(&pwm_lock);
280 return ret;
281 }
282 EXPORT_SYMBOL_GPL(pwmchip_add);
283
284 /**
285 * pwmchip_remove() - remove a PWM chip
286 * @chip: the PWM chip to remove
287 *
288 * Removes a PWM chip. This function may return busy if the PWM chip provides
289 * a PWM device that is still requested.
290 */
pwmchip_remove(struct pwm_chip * chip)291 int pwmchip_remove(struct pwm_chip *chip)
292 {
293 unsigned int i;
294 int ret = 0;
295
296 pwmchip_sysfs_unexport_children(chip);
297
298 mutex_lock(&pwm_lock);
299
300 for (i = 0; i < chip->npwm; i++) {
301 struct pwm_device *pwm = &chip->pwms[i];
302
303 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
304 ret = -EBUSY;
305 goto out;
306 }
307 }
308
309 list_del_init(&chip->list);
310
311 if (IS_ENABLED(CONFIG_OF))
312 of_pwmchip_remove(chip);
313
314 free_pwms(chip);
315
316 pwmchip_sysfs_unexport(chip);
317
318 out:
319 mutex_unlock(&pwm_lock);
320 return ret;
321 }
322 EXPORT_SYMBOL_GPL(pwmchip_remove);
323
324 /**
325 * pwm_request() - request a PWM device
326 * @pwm_id: global PWM device index
327 * @label: PWM device label
328 *
329 * This function is deprecated, use pwm_get() instead.
330 */
pwm_request(int pwm,const char * label)331 struct pwm_device *pwm_request(int pwm, const char *label)
332 {
333 struct pwm_device *dev;
334 int err;
335
336 if (pwm < 0 || pwm >= MAX_PWMS)
337 return ERR_PTR(-EINVAL);
338
339 mutex_lock(&pwm_lock);
340
341 dev = pwm_to_device(pwm);
342 if (!dev) {
343 dev = ERR_PTR(-EPROBE_DEFER);
344 goto out;
345 }
346
347 err = pwm_device_request(dev, label);
348 if (err < 0)
349 dev = ERR_PTR(err);
350
351 out:
352 mutex_unlock(&pwm_lock);
353
354 return dev;
355 }
356 EXPORT_SYMBOL_GPL(pwm_request);
357
358 /**
359 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
360 * @chip: PWM chip
361 * @index: per-chip index of the PWM to request
362 * @label: a literal description string of this PWM
363 *
364 * Returns the PWM at the given index of the given PWM chip. A negative error
365 * code is returned if the index is not valid for the specified PWM chip or
366 * if the PWM device cannot be requested.
367 */
pwm_request_from_chip(struct pwm_chip * chip,unsigned int index,const char * label)368 struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
369 unsigned int index,
370 const char *label)
371 {
372 struct pwm_device *pwm;
373 int err;
374
375 if (!chip || index >= chip->npwm)
376 return ERR_PTR(-EINVAL);
377
378 mutex_lock(&pwm_lock);
379 pwm = &chip->pwms[index];
380
381 err = pwm_device_request(pwm, label);
382 if (err < 0)
383 pwm = ERR_PTR(err);
384
385 mutex_unlock(&pwm_lock);
386 return pwm;
387 }
388 EXPORT_SYMBOL_GPL(pwm_request_from_chip);
389
390 /**
391 * pwm_free() - free a PWM device
392 * @pwm: PWM device
393 *
394 * This function is deprecated, use pwm_put() instead.
395 */
pwm_free(struct pwm_device * pwm)396 void pwm_free(struct pwm_device *pwm)
397 {
398 pwm_put(pwm);
399 }
400 EXPORT_SYMBOL_GPL(pwm_free);
401
402 /**
403 * pwm_config() - change a PWM device configuration
404 * @pwm: PWM device
405 * @duty_ns: "on" time (in nanoseconds)
406 * @period_ns: duration (in nanoseconds) of one cycle
407 */
pwm_config(struct pwm_device * pwm,int duty_ns,int period_ns)408 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
409 {
410 int err;
411
412 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
413 return -EINVAL;
414
415 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
416 if (err)
417 return err;
418
419 pwm->duty_cycle = duty_ns;
420 pwm->period = period_ns;
421
422 return 0;
423 }
424 EXPORT_SYMBOL_GPL(pwm_config);
425
426 /**
427 * pwm_set_polarity() - configure the polarity of a PWM signal
428 * @pwm: PWM device
429 * @polarity: new polarity of the PWM signal
430 *
431 * Note that the polarity cannot be configured while the PWM device is enabled
432 */
pwm_set_polarity(struct pwm_device * pwm,enum pwm_polarity polarity)433 int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
434 {
435 int err;
436
437 if (!pwm || !pwm->chip->ops)
438 return -EINVAL;
439
440 if (!pwm->chip->ops->set_polarity)
441 return -ENOSYS;
442
443 if (test_bit(PWMF_ENABLED, &pwm->flags))
444 return -EBUSY;
445
446 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
447 if (err)
448 return err;
449
450 pwm->polarity = polarity;
451
452 return 0;
453 }
454 EXPORT_SYMBOL_GPL(pwm_set_polarity);
455
456 /**
457 * pwm_enable() - start a PWM output toggling
458 * @pwm: PWM device
459 */
pwm_enable(struct pwm_device * pwm)460 int pwm_enable(struct pwm_device *pwm)
461 {
462 if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
463 return pwm->chip->ops->enable(pwm->chip, pwm);
464
465 return pwm ? 0 : -EINVAL;
466 }
467 EXPORT_SYMBOL_GPL(pwm_enable);
468
469 /**
470 * pwm_disable() - stop a PWM output toggling
471 * @pwm: PWM device
472 */
pwm_disable(struct pwm_device * pwm)473 void pwm_disable(struct pwm_device *pwm)
474 {
475 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
476 pwm->chip->ops->disable(pwm->chip, pwm);
477 }
478 EXPORT_SYMBOL_GPL(pwm_disable);
479
of_node_to_pwmchip(struct device_node * np)480 static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
481 {
482 struct pwm_chip *chip;
483
484 mutex_lock(&pwm_lock);
485
486 list_for_each_entry(chip, &pwm_chips, list)
487 if (chip->dev && chip->dev->of_node == np) {
488 mutex_unlock(&pwm_lock);
489 return chip;
490 }
491
492 mutex_unlock(&pwm_lock);
493
494 return ERR_PTR(-EPROBE_DEFER);
495 }
496
497 /**
498 * of_pwm_get() - request a PWM via the PWM framework
499 * @np: device node to get the PWM from
500 * @con_id: consumer name
501 *
502 * Returns the PWM device parsed from the phandle and index specified in the
503 * "pwms" property of a device tree node or a negative error-code on failure.
504 * Values parsed from the device tree are stored in the returned PWM device
505 * object.
506 *
507 * If con_id is NULL, the first PWM device listed in the "pwms" property will
508 * be requested. Otherwise the "pwm-names" property is used to do a reverse
509 * lookup of the PWM index. This also means that the "pwm-names" property
510 * becomes mandatory for devices that look up the PWM device via the con_id
511 * parameter.
512 */
of_pwm_get(struct device_node * np,const char * con_id)513 struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
514 {
515 struct pwm_device *pwm = NULL;
516 struct of_phandle_args args;
517 struct pwm_chip *pc;
518 int index = 0;
519 int err;
520
521 if (con_id) {
522 index = of_property_match_string(np, "pwm-names", con_id);
523 if (index < 0)
524 return ERR_PTR(index);
525 }
526
527 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
528 &args);
529 if (err) {
530 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
531 return ERR_PTR(err);
532 }
533
534 pc = of_node_to_pwmchip(args.np);
535 if (IS_ERR(pc)) {
536 pr_debug("%s(): PWM chip not found\n", __func__);
537 pwm = ERR_CAST(pc);
538 goto put;
539 }
540
541 if (args.args_count != pc->of_pwm_n_cells) {
542 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
543 args.np->full_name);
544 pwm = ERR_PTR(-EINVAL);
545 goto put;
546 }
547
548 pwm = pc->of_xlate(pc, &args);
549 if (IS_ERR(pwm))
550 goto put;
551
552 /*
553 * If a consumer name was not given, try to look it up from the
554 * "pwm-names" property if it exists. Otherwise use the name of
555 * the user device node.
556 */
557 if (!con_id) {
558 err = of_property_read_string_index(np, "pwm-names", index,
559 &con_id);
560 if (err < 0)
561 con_id = np->name;
562 }
563
564 pwm->label = con_id;
565
566 put:
567 of_node_put(args.np);
568
569 return pwm;
570 }
571 EXPORT_SYMBOL_GPL(of_pwm_get);
572
573 /**
574 * pwm_add_table() - register PWM device consumers
575 * @table: array of consumers to register
576 * @num: number of consumers in table
577 */
pwm_add_table(struct pwm_lookup * table,size_t num)578 void __init pwm_add_table(struct pwm_lookup *table, size_t num)
579 {
580 mutex_lock(&pwm_lookup_lock);
581
582 while (num--) {
583 list_add_tail(&table->list, &pwm_lookup_list);
584 table++;
585 }
586
587 mutex_unlock(&pwm_lookup_lock);
588 }
589
590 /**
591 * pwm_get() - look up and request a PWM device
592 * @dev: device for PWM consumer
593 * @con_id: consumer name
594 *
595 * Lookup is first attempted using DT. If the device was not instantiated from
596 * a device tree, a PWM chip and a relative index is looked up via a table
597 * supplied by board setup code (see pwm_add_table()).
598 *
599 * Once a PWM chip has been found the specified PWM device will be requested
600 * and is ready to be used.
601 */
pwm_get(struct device * dev,const char * con_id)602 struct pwm_device *pwm_get(struct device *dev, const char *con_id)
603 {
604 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
605 const char *dev_id = dev ? dev_name(dev) : NULL;
606 struct pwm_chip *chip = NULL;
607 unsigned int best = 0;
608 struct pwm_lookup *p, *chosen = NULL;
609 unsigned int match;
610
611 /* look up via DT first */
612 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
613 return of_pwm_get(dev->of_node, con_id);
614
615 /*
616 * We look up the provider in the static table typically provided by
617 * board setup code. We first try to lookup the consumer device by
618 * name. If the consumer device was passed in as NULL or if no match
619 * was found, we try to find the consumer by directly looking it up
620 * by name.
621 *
622 * If a match is found, the provider PWM chip is looked up by name
623 * and a PWM device is requested using the PWM device per-chip index.
624 *
625 * The lookup algorithm was shamelessly taken from the clock
626 * framework:
627 *
628 * We do slightly fuzzy matching here:
629 * An entry with a NULL ID is assumed to be a wildcard.
630 * If an entry has a device ID, it must match
631 * If an entry has a connection ID, it must match
632 * Then we take the most specific entry - with the following order
633 * of precedence: dev+con > dev only > con only.
634 */
635 mutex_lock(&pwm_lookup_lock);
636
637 list_for_each_entry(p, &pwm_lookup_list, list) {
638 match = 0;
639
640 if (p->dev_id) {
641 if (!dev_id || strcmp(p->dev_id, dev_id))
642 continue;
643
644 match += 2;
645 }
646
647 if (p->con_id) {
648 if (!con_id || strcmp(p->con_id, con_id))
649 continue;
650
651 match += 1;
652 }
653
654 if (match > best) {
655 chosen = p;
656
657 if (match != 3)
658 best = match;
659 else
660 break;
661 }
662 }
663
664 if (!chosen)
665 goto out;
666
667 chip = pwmchip_find_by_name(chosen->provider);
668 if (!chip)
669 goto out;
670
671 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
672 if (IS_ERR(pwm))
673 goto out;
674
675 pwm_set_period(pwm, chosen->period);
676 pwm_set_polarity(pwm, chosen->polarity);
677
678 out:
679 mutex_unlock(&pwm_lookup_lock);
680 return pwm;
681 }
682 EXPORT_SYMBOL_GPL(pwm_get);
683
684 /**
685 * pwm_put() - release a PWM device
686 * @pwm: PWM device
687 */
pwm_put(struct pwm_device * pwm)688 void pwm_put(struct pwm_device *pwm)
689 {
690 if (!pwm)
691 return;
692
693 mutex_lock(&pwm_lock);
694
695 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
696 pr_warn("PWM device already freed\n");
697 goto out;
698 }
699
700 if (pwm->chip->ops->free)
701 pwm->chip->ops->free(pwm->chip, pwm);
702
703 pwm->label = NULL;
704
705 module_put(pwm->chip->ops->owner);
706 out:
707 mutex_unlock(&pwm_lock);
708 }
709 EXPORT_SYMBOL_GPL(pwm_put);
710
devm_pwm_release(struct device * dev,void * res)711 static void devm_pwm_release(struct device *dev, void *res)
712 {
713 pwm_put(*(struct pwm_device **)res);
714 }
715
716 /**
717 * devm_pwm_get() - resource managed pwm_get()
718 * @dev: device for PWM consumer
719 * @con_id: consumer name
720 *
721 * This function performs like pwm_get() but the acquired PWM device will
722 * automatically be released on driver detach.
723 */
devm_pwm_get(struct device * dev,const char * con_id)724 struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
725 {
726 struct pwm_device **ptr, *pwm;
727
728 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
729 if (!ptr)
730 return ERR_PTR(-ENOMEM);
731
732 pwm = pwm_get(dev, con_id);
733 if (!IS_ERR(pwm)) {
734 *ptr = pwm;
735 devres_add(dev, ptr);
736 } else {
737 devres_free(ptr);
738 }
739
740 return pwm;
741 }
742 EXPORT_SYMBOL_GPL(devm_pwm_get);
743
744 /**
745 * devm_of_pwm_get() - resource managed of_pwm_get()
746 * @dev: device for PWM consumer
747 * @np: device node to get the PWM from
748 * @con_id: consumer name
749 *
750 * This function performs like of_pwm_get() but the acquired PWM device will
751 * automatically be released on driver detach.
752 */
devm_of_pwm_get(struct device * dev,struct device_node * np,const char * con_id)753 struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
754 const char *con_id)
755 {
756 struct pwm_device **ptr, *pwm;
757
758 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
759 if (!ptr)
760 return ERR_PTR(-ENOMEM);
761
762 pwm = of_pwm_get(np, con_id);
763 if (!IS_ERR(pwm)) {
764 *ptr = pwm;
765 devres_add(dev, ptr);
766 } else {
767 devres_free(ptr);
768 }
769
770 return pwm;
771 }
772 EXPORT_SYMBOL_GPL(devm_of_pwm_get);
773
devm_pwm_match(struct device * dev,void * res,void * data)774 static int devm_pwm_match(struct device *dev, void *res, void *data)
775 {
776 struct pwm_device **p = res;
777
778 if (WARN_ON(!p || !*p))
779 return 0;
780
781 return *p == data;
782 }
783
784 /**
785 * devm_pwm_put() - resource managed pwm_put()
786 * @dev: device for PWM consumer
787 * @pwm: PWM device
788 *
789 * Release a PWM previously allocated using devm_pwm_get(). Calling this
790 * function is usually not needed because devm-allocated resources are
791 * automatically released on driver detach.
792 */
devm_pwm_put(struct device * dev,struct pwm_device * pwm)793 void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
794 {
795 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
796 }
797 EXPORT_SYMBOL_GPL(devm_pwm_put);
798
799 /**
800 * pwm_can_sleep() - report whether PWM access will sleep
801 * @pwm: PWM device
802 *
803 * It returns true if accessing the PWM can sleep, false otherwise.
804 */
pwm_can_sleep(struct pwm_device * pwm)805 bool pwm_can_sleep(struct pwm_device *pwm)
806 {
807 return pwm->chip->can_sleep;
808 }
809 EXPORT_SYMBOL_GPL(pwm_can_sleep);
810
811 #ifdef CONFIG_DEBUG_FS
pwm_dbg_show(struct pwm_chip * chip,struct seq_file * s)812 static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
813 {
814 unsigned int i;
815
816 for (i = 0; i < chip->npwm; i++) {
817 struct pwm_device *pwm = &chip->pwms[i];
818
819 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
820
821 if (test_bit(PWMF_REQUESTED, &pwm->flags))
822 seq_puts(s, " requested");
823
824 if (test_bit(PWMF_ENABLED, &pwm->flags))
825 seq_puts(s, " enabled");
826
827 seq_puts(s, "\n");
828 }
829 }
830
pwm_seq_start(struct seq_file * s,loff_t * pos)831 static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
832 {
833 mutex_lock(&pwm_lock);
834 s->private = "";
835
836 return seq_list_start(&pwm_chips, *pos);
837 }
838
pwm_seq_next(struct seq_file * s,void * v,loff_t * pos)839 static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
840 {
841 s->private = "\n";
842
843 return seq_list_next(v, &pwm_chips, pos);
844 }
845
pwm_seq_stop(struct seq_file * s,void * v)846 static void pwm_seq_stop(struct seq_file *s, void *v)
847 {
848 mutex_unlock(&pwm_lock);
849 }
850
pwm_seq_show(struct seq_file * s,void * v)851 static int pwm_seq_show(struct seq_file *s, void *v)
852 {
853 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
854
855 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
856 chip->dev->bus ? chip->dev->bus->name : "no-bus",
857 dev_name(chip->dev), chip->npwm,
858 (chip->npwm != 1) ? "s" : "");
859
860 if (chip->ops->dbg_show)
861 chip->ops->dbg_show(chip, s);
862 else
863 pwm_dbg_show(chip, s);
864
865 return 0;
866 }
867
868 static const struct seq_operations pwm_seq_ops = {
869 .start = pwm_seq_start,
870 .next = pwm_seq_next,
871 .stop = pwm_seq_stop,
872 .show = pwm_seq_show,
873 };
874
pwm_seq_open(struct inode * inode,struct file * file)875 static int pwm_seq_open(struct inode *inode, struct file *file)
876 {
877 return seq_open(file, &pwm_seq_ops);
878 }
879
880 static const struct file_operations pwm_debugfs_ops = {
881 .owner = THIS_MODULE,
882 .open = pwm_seq_open,
883 .read = seq_read,
884 .llseek = seq_lseek,
885 .release = seq_release,
886 };
887
pwm_debugfs_init(void)888 static int __init pwm_debugfs_init(void)
889 {
890 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
891 &pwm_debugfs_ops);
892
893 return 0;
894 }
895
896 subsys_initcall(pwm_debugfs_init);
897 #endif /* CONFIG_DEBUG_FS */
898