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