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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Generic pwmlib implementation
4 *
5 * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de>
6 * Copyright (C) 2011-2012 Avionic Design GmbH
7 */
8
9#include <linux/acpi.h>
10#include <linux/module.h>
11#include <linux/pwm.h>
12#include <linux/radix-tree.h>
13#include <linux/list.h>
14#include <linux/mutex.h>
15#include <linux/err.h>
16#include <linux/slab.h>
17#include <linux/device.h>
18#include <linux/debugfs.h>
19#include <linux/seq_file.h>
20
21#include <dt-bindings/pwm/pwm.h>
22
23#define CREATE_TRACE_POINTS
24#include <trace/events/pwm.h>
25
26#define MAX_PWMS 1024
27
28static DEFINE_MUTEX(pwm_lookup_lock);
29static LIST_HEAD(pwm_lookup_list);
30
31/* protects access to pwm_chips, allocated_pwms, and pwm_tree */
32static DEFINE_MUTEX(pwm_lock);
33
34static LIST_HEAD(pwm_chips);
35static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
36static RADIX_TREE(pwm_tree, GFP_KERNEL);
37
38static struct pwm_device *pwm_to_device(unsigned int pwm)
39{
40 return radix_tree_lookup(&pwm_tree, pwm);
41}
42
43/* Called with pwm_lock held */
44static int alloc_pwms(unsigned int count)
45{
46 unsigned int start;
47
48 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, 0,
49 count, 0);
50
51 if (start + count > MAX_PWMS)
52 return -ENOSPC;
53
54 bitmap_set(allocated_pwms, start, count);
55
56 return start;
57}
58
59/* Called with pwm_lock held */
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 if (pwm->chip->ops->get_state) {
118 struct pwm_state state;
119
120 err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
121 trace_pwm_get(pwm, &state, err);
122
123 if (!err)
124 pwm->state = state;
125
126 if (IS_ENABLED(CONFIG_PWM_DEBUG))
127 pwm->last = pwm->state;
128 }
129
130 set_bit(PWMF_REQUESTED, &pwm->flags);
131 pwm->label = label;
132
133 return 0;
134}
135
136struct pwm_device *
137of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
138{
139 struct pwm_device *pwm;
140
141 if (pc->of_pwm_n_cells < 2)
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 (pc->of_pwm_n_cells >= 3) {
159 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
160 pwm->args.polarity = PWM_POLARITY_INVERSED;
161 }
162
163 return pwm;
164}
165EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
166
167struct pwm_device *
168of_pwm_single_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
169{
170 struct pwm_device *pwm;
171
172 if (pc->of_pwm_n_cells < 1)
173 return ERR_PTR(-EINVAL);
174
175 /* validate that one cell is specified, optionally with flags */
176 if (args->args_count != 1 && args->args_count != 2)
177 return ERR_PTR(-EINVAL);
178
179 pwm = pwm_request_from_chip(pc, 0, NULL);
180 if (IS_ERR(pwm))
181 return pwm;
182
183 pwm->args.period = args->args[0];
184 pwm->args.polarity = PWM_POLARITY_NORMAL;
185
186 if (args->args_count == 2 && args->args[2] & PWM_POLARITY_INVERTED)
187 pwm->args.polarity = PWM_POLARITY_INVERSED;
188
189 return pwm;
190}
191EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
192
193static void of_pwmchip_add(struct pwm_chip *chip)
194{
195 if (!chip->dev || !chip->dev->of_node)
196 return;
197
198 if (!chip->of_xlate) {
199 u32 pwm_cells;
200
201 if (of_property_read_u32(chip->dev->of_node, "#pwm-cells",
202 &pwm_cells))
203 pwm_cells = 2;
204
205 chip->of_xlate = of_pwm_xlate_with_flags;
206 chip->of_pwm_n_cells = pwm_cells;
207 }
208
209 of_node_get(chip->dev->of_node);
210}
211
212static void of_pwmchip_remove(struct pwm_chip *chip)
213{
214 if (chip->dev)
215 of_node_put(chip->dev->of_node);
216}
217
218/**
219 * pwm_set_chip_data() - set private chip data for a PWM
220 * @pwm: PWM device
221 * @data: pointer to chip-specific data
222 *
223 * Returns: 0 on success or a negative error code on failure.
224 */
225int pwm_set_chip_data(struct pwm_device *pwm, void *data)
226{
227 if (!pwm)
228 return -EINVAL;
229
230 pwm->chip_data = data;
231
232 return 0;
233}
234EXPORT_SYMBOL_GPL(pwm_set_chip_data);
235
236/**
237 * pwm_get_chip_data() - get private chip data for a PWM
238 * @pwm: PWM device
239 *
240 * Returns: A pointer to the chip-private data for the PWM device.
241 */
242void *pwm_get_chip_data(struct pwm_device *pwm)
243{
244 return pwm ? pwm->chip_data : NULL;
245}
246EXPORT_SYMBOL_GPL(pwm_get_chip_data);
247
248static bool pwm_ops_check(const struct pwm_chip *chip)
249{
250 const struct pwm_ops *ops = chip->ops;
251
252 if (!ops->apply)
253 return false;
254
255 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
256 dev_warn(chip->dev,
257 "Please implement the .get_state() callback\n");
258
259 return true;
260}
261
262/**
263 * pwmchip_add() - register a new PWM chip
264 * @chip: the PWM chip to add
265 *
266 * Register a new PWM chip.
267 *
268 * Returns: 0 on success or a negative error code on failure.
269 */
270int pwmchip_add(struct pwm_chip *chip)
271{
272 struct pwm_device *pwm;
273 unsigned int i;
274 int ret;
275
276 if (!chip || !chip->dev || !chip->ops || !chip->npwm)
277 return -EINVAL;
278
279 if (!pwm_ops_check(chip))
280 return -EINVAL;
281
282 chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
283 if (!chip->pwms)
284 return -ENOMEM;
285
286 mutex_lock(&pwm_lock);
287
288 ret = alloc_pwms(chip->npwm);
289 if (ret < 0) {
290 mutex_unlock(&pwm_lock);
291 kfree(chip->pwms);
292 return ret;
293 }
294
295 chip->base = ret;
296
297 for (i = 0; i < chip->npwm; i++) {
298 pwm = &chip->pwms[i];
299
300 pwm->chip = chip;
301 pwm->pwm = chip->base + i;
302 pwm->hwpwm = i;
303
304 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
305 }
306
307 list_add(&chip->list, &pwm_chips);
308
309 mutex_unlock(&pwm_lock);
310
311 if (IS_ENABLED(CONFIG_OF))
312 of_pwmchip_add(chip);
313
314 pwmchip_sysfs_export(chip);
315
316 return 0;
317}
318EXPORT_SYMBOL_GPL(pwmchip_add);
319
320/**
321 * pwmchip_remove() - remove a PWM chip
322 * @chip: the PWM chip to remove
323 *
324 * Removes a PWM chip. This function may return busy if the PWM chip provides
325 * a PWM device that is still requested.
326 *
327 * Returns: 0 on success or a negative error code on failure.
328 */
329void pwmchip_remove(struct pwm_chip *chip)
330{
331 pwmchip_sysfs_unexport(chip);
332
333 mutex_lock(&pwm_lock);
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 mutex_unlock(&pwm_lock);
343}
344EXPORT_SYMBOL_GPL(pwmchip_remove);
345
346static void devm_pwmchip_remove(void *data)
347{
348 struct pwm_chip *chip = data;
349
350 pwmchip_remove(chip);
351}
352
353int devm_pwmchip_add(struct device *dev, struct pwm_chip *chip)
354{
355 int ret;
356
357 ret = pwmchip_add(chip);
358 if (ret)
359 return ret;
360
361 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
362}
363EXPORT_SYMBOL_GPL(devm_pwmchip_add);
364
365/**
366 * pwm_request() - request a PWM device
367 * @pwm: global PWM device index
368 * @label: PWM device label
369 *
370 * This function is deprecated, use pwm_get() instead.
371 *
372 * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on
373 * failure.
374 */
375struct pwm_device *pwm_request(int pwm, const char *label)
376{
377 struct pwm_device *dev;
378 int err;
379
380 if (pwm < 0 || pwm >= MAX_PWMS)
381 return ERR_PTR(-EINVAL);
382
383 mutex_lock(&pwm_lock);
384
385 dev = pwm_to_device(pwm);
386 if (!dev) {
387 dev = ERR_PTR(-EPROBE_DEFER);
388 goto out;
389 }
390
391 err = pwm_device_request(dev, label);
392 if (err < 0)
393 dev = ERR_PTR(err);
394
395out:
396 mutex_unlock(&pwm_lock);
397
398 return dev;
399}
400EXPORT_SYMBOL_GPL(pwm_request);
401
402/**
403 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
404 * @chip: PWM chip
405 * @index: per-chip index of the PWM to request
406 * @label: a literal description string of this PWM
407 *
408 * Returns: A pointer to the PWM device at the given index of the given PWM
409 * chip. A negative error code is returned if the index is not valid for the
410 * specified PWM chip or if the PWM device cannot be requested.
411 */
412struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
413 unsigned int index,
414 const char *label)
415{
416 struct pwm_device *pwm;
417 int err;
418
419 if (!chip || index >= chip->npwm)
420 return ERR_PTR(-EINVAL);
421
422 mutex_lock(&pwm_lock);
423 pwm = &chip->pwms[index];
424
425 err = pwm_device_request(pwm, label);
426 if (err < 0)
427 pwm = ERR_PTR(err);
428
429 mutex_unlock(&pwm_lock);
430 return pwm;
431}
432EXPORT_SYMBOL_GPL(pwm_request_from_chip);
433
434/**
435 * pwm_free() - free a PWM device
436 * @pwm: PWM device
437 *
438 * This function is deprecated, use pwm_put() instead.
439 */
440void pwm_free(struct pwm_device *pwm)
441{
442 pwm_put(pwm);
443}
444EXPORT_SYMBOL_GPL(pwm_free);
445
446static void pwm_apply_state_debug(struct pwm_device *pwm,
447 const struct pwm_state *state)
448{
449 struct pwm_state *last = &pwm->last;
450 struct pwm_chip *chip = pwm->chip;
451 struct pwm_state s1, s2;
452 int err;
453
454 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
455 return;
456
457 /* No reasonable diagnosis possible without .get_state() */
458 if (!chip->ops->get_state)
459 return;
460
461 /*
462 * *state was just applied. Read out the hardware state and do some
463 * checks.
464 */
465
466 err = chip->ops->get_state(chip, pwm, &s1);
467 trace_pwm_get(pwm, &s1, err);
468 if (err)
469 /* If that failed there isn't much to debug */
470 return;
471
472 /*
473 * The lowlevel driver either ignored .polarity (which is a bug) or as
474 * best effort inverted .polarity and fixed .duty_cycle respectively.
475 * Undo this inversion and fixup for further tests.
476 */
477 if (s1.enabled && s1.polarity != state->polarity) {
478 s2.polarity = state->polarity;
479 s2.duty_cycle = s1.period - s1.duty_cycle;
480 s2.period = s1.period;
481 s2.enabled = s1.enabled;
482 } else {
483 s2 = s1;
484 }
485
486 if (s2.polarity != state->polarity &&
487 state->duty_cycle < state->period)
488 dev_warn(chip->dev, ".apply ignored .polarity\n");
489
490 if (state->enabled &&
491 last->polarity == state->polarity &&
492 last->period > s2.period &&
493 last->period <= state->period)
494 dev_warn(chip->dev,
495 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
496 state->period, s2.period, last->period);
497
498 if (state->enabled && state->period < s2.period)
499 dev_warn(chip->dev,
500 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
501 state->period, s2.period);
502
503 if (state->enabled &&
504 last->polarity == state->polarity &&
505 last->period == s2.period &&
506 last->duty_cycle > s2.duty_cycle &&
507 last->duty_cycle <= state->duty_cycle)
508 dev_warn(chip->dev,
509 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
510 state->duty_cycle, state->period,
511 s2.duty_cycle, s2.period,
512 last->duty_cycle, last->period);
513
514 if (state->enabled && state->duty_cycle < s2.duty_cycle)
515 dev_warn(chip->dev,
516 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
517 state->duty_cycle, state->period,
518 s2.duty_cycle, s2.period);
519
520 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
521 dev_warn(chip->dev,
522 "requested disabled, but yielded enabled with duty > 0\n");
523
524 /* reapply the state that the driver reported being configured. */
525 err = chip->ops->apply(chip, pwm, &s1);
526 trace_pwm_apply(pwm, &s1, err);
527 if (err) {
528 *last = s1;
529 dev_err(chip->dev, "failed to reapply current setting\n");
530 return;
531 }
532
533 err = chip->ops->get_state(chip, pwm, last);
534 trace_pwm_get(pwm, last, err);
535 if (err)
536 return;
537
538 /* reapplication of the current state should give an exact match */
539 if (s1.enabled != last->enabled ||
540 s1.polarity != last->polarity ||
541 (s1.enabled && s1.period != last->period) ||
542 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
543 dev_err(chip->dev,
544 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
545 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
546 last->enabled, last->polarity, last->duty_cycle,
547 last->period);
548 }
549}
550
551/**
552 * pwm_apply_state() - atomically apply a new state to a PWM device
553 * @pwm: PWM device
554 * @state: new state to apply
555 */
556int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
557{
558 struct pwm_chip *chip;
559 int err;
560
561 /*
562 * Some lowlevel driver's implementations of .apply() make use of
563 * mutexes, also with some drivers only returning when the new
564 * configuration is active calling pwm_apply_state() from atomic context
565 * is a bad idea. So make it explicit that calling this function might
566 * sleep.
567 */
568 might_sleep();
569
570 if (!pwm || !state || !state->period ||
571 state->duty_cycle > state->period)
572 return -EINVAL;
573
574 chip = pwm->chip;
575
576 if (state->period == pwm->state.period &&
577 state->duty_cycle == pwm->state.duty_cycle &&
578 state->polarity == pwm->state.polarity &&
579 state->enabled == pwm->state.enabled &&
580 state->usage_power == pwm->state.usage_power)
581 return 0;
582
583 err = chip->ops->apply(chip, pwm, state);
584 trace_pwm_apply(pwm, state, err);
585 if (err)
586 return err;
587
588 pwm->state = *state;
589
590 /*
591 * only do this after pwm->state was applied as some
592 * implementations of .get_state depend on this
593 */
594 pwm_apply_state_debug(pwm, state);
595
596 return 0;
597}
598EXPORT_SYMBOL_GPL(pwm_apply_state);
599
600/**
601 * pwm_capture() - capture and report a PWM signal
602 * @pwm: PWM device
603 * @result: structure to fill with capture result
604 * @timeout: time to wait, in milliseconds, before giving up on capture
605 *
606 * Returns: 0 on success or a negative error code on failure.
607 */
608int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
609 unsigned long timeout)
610{
611 int err;
612
613 if (!pwm || !pwm->chip->ops)
614 return -EINVAL;
615
616 if (!pwm->chip->ops->capture)
617 return -ENOSYS;
618
619 mutex_lock(&pwm_lock);
620 err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
621 mutex_unlock(&pwm_lock);
622
623 return err;
624}
625EXPORT_SYMBOL_GPL(pwm_capture);
626
627/**
628 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
629 * @pwm: PWM device
630 *
631 * This function will adjust the PWM config to the PWM arguments provided
632 * by the DT or PWM lookup table. This is particularly useful to adapt
633 * the bootloader config to the Linux one.
634 */
635int pwm_adjust_config(struct pwm_device *pwm)
636{
637 struct pwm_state state;
638 struct pwm_args pargs;
639
640 pwm_get_args(pwm, &pargs);
641 pwm_get_state(pwm, &state);
642
643 /*
644 * If the current period is zero it means that either the PWM driver
645 * does not support initial state retrieval or the PWM has not yet
646 * been configured.
647 *
648 * In either case, we setup the new period and polarity, and assign a
649 * duty cycle of 0.
650 */
651 if (!state.period) {
652 state.duty_cycle = 0;
653 state.period = pargs.period;
654 state.polarity = pargs.polarity;
655
656 return pwm_apply_state(pwm, &state);
657 }
658
659 /*
660 * Adjust the PWM duty cycle/period based on the period value provided
661 * in PWM args.
662 */
663 if (pargs.period != state.period) {
664 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
665
666 do_div(dutycycle, state.period);
667 state.duty_cycle = dutycycle;
668 state.period = pargs.period;
669 }
670
671 /*
672 * If the polarity changed, we should also change the duty cycle.
673 */
674 if (pargs.polarity != state.polarity) {
675 state.polarity = pargs.polarity;
676 state.duty_cycle = state.period - state.duty_cycle;
677 }
678
679 return pwm_apply_state(pwm, &state);
680}
681EXPORT_SYMBOL_GPL(pwm_adjust_config);
682
683static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
684{
685 struct pwm_chip *chip;
686
687 mutex_lock(&pwm_lock);
688
689 list_for_each_entry(chip, &pwm_chips, list)
690 if (chip->dev && device_match_fwnode(chip->dev, fwnode)) {
691 mutex_unlock(&pwm_lock);
692 return chip;
693 }
694
695 mutex_unlock(&pwm_lock);
696
697 return ERR_PTR(-EPROBE_DEFER);
698}
699
700static struct device_link *pwm_device_link_add(struct device *dev,
701 struct pwm_device *pwm)
702{
703 struct device_link *dl;
704
705 if (!dev) {
706 /*
707 * No device for the PWM consumer has been provided. It may
708 * impact the PM sequence ordering: the PWM supplier may get
709 * suspended before the consumer.
710 */
711 dev_warn(pwm->chip->dev,
712 "No consumer device specified to create a link to\n");
713 return NULL;
714 }
715
716 dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
717 if (!dl) {
718 dev_err(dev, "failed to create device link to %s\n",
719 dev_name(pwm->chip->dev));
720 return ERR_PTR(-EINVAL);
721 }
722
723 return dl;
724}
725
726/**
727 * of_pwm_get() - request a PWM via the PWM framework
728 * @dev: device for PWM consumer
729 * @np: device node to get the PWM from
730 * @con_id: consumer name
731 *
732 * Returns the PWM device parsed from the phandle and index specified in the
733 * "pwms" property of a device tree node or a negative error-code on failure.
734 * Values parsed from the device tree are stored in the returned PWM device
735 * object.
736 *
737 * If con_id is NULL, the first PWM device listed in the "pwms" property will
738 * be requested. Otherwise the "pwm-names" property is used to do a reverse
739 * lookup of the PWM index. This also means that the "pwm-names" property
740 * becomes mandatory for devices that look up the PWM device via the con_id
741 * parameter.
742 *
743 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
744 * error code on failure.
745 */
746static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
747 const char *con_id)
748{
749 struct pwm_device *pwm = NULL;
750 struct of_phandle_args args;
751 struct device_link *dl;
752 struct pwm_chip *pc;
753 int index = 0;
754 int err;
755
756 if (con_id) {
757 index = of_property_match_string(np, "pwm-names", con_id);
758 if (index < 0)
759 return ERR_PTR(index);
760 }
761
762 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
763 &args);
764 if (err) {
765 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
766 return ERR_PTR(err);
767 }
768
769 pc = fwnode_to_pwmchip(of_fwnode_handle(args.np));
770 if (IS_ERR(pc)) {
771 if (PTR_ERR(pc) != -EPROBE_DEFER)
772 pr_err("%s(): PWM chip not found\n", __func__);
773
774 pwm = ERR_CAST(pc);
775 goto put;
776 }
777
778 pwm = pc->of_xlate(pc, &args);
779 if (IS_ERR(pwm))
780 goto put;
781
782 dl = pwm_device_link_add(dev, pwm);
783 if (IS_ERR(dl)) {
784 /* of_xlate ended up calling pwm_request_from_chip() */
785 pwm_free(pwm);
786 pwm = ERR_CAST(dl);
787 goto put;
788 }
789
790 /*
791 * If a consumer name was not given, try to look it up from the
792 * "pwm-names" property if it exists. Otherwise use the name of
793 * the user device node.
794 */
795 if (!con_id) {
796 err = of_property_read_string_index(np, "pwm-names", index,
797 &con_id);
798 if (err < 0)
799 con_id = np->name;
800 }
801
802 pwm->label = con_id;
803
804put:
805 of_node_put(args.np);
806
807 return pwm;
808}
809
810/**
811 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
812 * @fwnode: firmware node to get the "pwms" property from
813 *
814 * Returns the PWM device parsed from the fwnode and index specified in the
815 * "pwms" property or a negative error-code on failure.
816 * Values parsed from the device tree are stored in the returned PWM device
817 * object.
818 *
819 * This is analogous to of_pwm_get() except con_id is not yet supported.
820 * ACPI entries must look like
821 * Package () {"pwms", Package ()
822 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
823 *
824 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
825 * error code on failure.
826 */
827static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
828{
829 struct pwm_device *pwm;
830 struct fwnode_reference_args args;
831 struct pwm_chip *chip;
832 int ret;
833
834 memset(&args, 0, sizeof(args));
835
836 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
837 if (ret < 0)
838 return ERR_PTR(ret);
839
840 if (args.nargs < 2)
841 return ERR_PTR(-EPROTO);
842
843 chip = fwnode_to_pwmchip(args.fwnode);
844 if (IS_ERR(chip))
845 return ERR_CAST(chip);
846
847 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
848 if (IS_ERR(pwm))
849 return pwm;
850
851 pwm->args.period = args.args[1];
852 pwm->args.polarity = PWM_POLARITY_NORMAL;
853
854 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
855 pwm->args.polarity = PWM_POLARITY_INVERSED;
856
857 return pwm;
858}
859
860/**
861 * pwm_add_table() - register PWM device consumers
862 * @table: array of consumers to register
863 * @num: number of consumers in table
864 */
865void pwm_add_table(struct pwm_lookup *table, size_t num)
866{
867 mutex_lock(&pwm_lookup_lock);
868
869 while (num--) {
870 list_add_tail(&table->list, &pwm_lookup_list);
871 table++;
872 }
873
874 mutex_unlock(&pwm_lookup_lock);
875}
876
877/**
878 * pwm_remove_table() - unregister PWM device consumers
879 * @table: array of consumers to unregister
880 * @num: number of consumers in table
881 */
882void pwm_remove_table(struct pwm_lookup *table, size_t num)
883{
884 mutex_lock(&pwm_lookup_lock);
885
886 while (num--) {
887 list_del(&table->list);
888 table++;
889 }
890
891 mutex_unlock(&pwm_lookup_lock);
892}
893
894/**
895 * pwm_get() - look up and request a PWM device
896 * @dev: device for PWM consumer
897 * @con_id: consumer name
898 *
899 * Lookup is first attempted using DT. If the device was not instantiated from
900 * a device tree, a PWM chip and a relative index is looked up via a table
901 * supplied by board setup code (see pwm_add_table()).
902 *
903 * Once a PWM chip has been found the specified PWM device will be requested
904 * and is ready to be used.
905 *
906 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
907 * error code on failure.
908 */
909struct pwm_device *pwm_get(struct device *dev, const char *con_id)
910{
911 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
912 const char *dev_id = dev ? dev_name(dev) : NULL;
913 struct pwm_device *pwm;
914 struct pwm_chip *chip;
915 struct device_link *dl;
916 unsigned int best = 0;
917 struct pwm_lookup *p, *chosen = NULL;
918 unsigned int match;
919 int err;
920
921 /* look up via DT first */
922 if (is_of_node(fwnode))
923 return of_pwm_get(dev, to_of_node(fwnode), con_id);
924
925 /* then lookup via ACPI */
926 if (is_acpi_node(fwnode)) {
927 pwm = acpi_pwm_get(fwnode);
928 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
929 return pwm;
930 }
931
932 /*
933 * We look up the provider in the static table typically provided by
934 * board setup code. We first try to lookup the consumer device by
935 * name. If the consumer device was passed in as NULL or if no match
936 * was found, we try to find the consumer by directly looking it up
937 * by name.
938 *
939 * If a match is found, the provider PWM chip is looked up by name
940 * and a PWM device is requested using the PWM device per-chip index.
941 *
942 * The lookup algorithm was shamelessly taken from the clock
943 * framework:
944 *
945 * We do slightly fuzzy matching here:
946 * An entry with a NULL ID is assumed to be a wildcard.
947 * If an entry has a device ID, it must match
948 * If an entry has a connection ID, it must match
949 * Then we take the most specific entry - with the following order
950 * of precedence: dev+con > dev only > con only.
951 */
952 mutex_lock(&pwm_lookup_lock);
953
954 list_for_each_entry(p, &pwm_lookup_list, list) {
955 match = 0;
956
957 if (p->dev_id) {
958 if (!dev_id || strcmp(p->dev_id, dev_id))
959 continue;
960
961 match += 2;
962 }
963
964 if (p->con_id) {
965 if (!con_id || strcmp(p->con_id, con_id))
966 continue;
967
968 match += 1;
969 }
970
971 if (match > best) {
972 chosen = p;
973
974 if (match != 3)
975 best = match;
976 else
977 break;
978 }
979 }
980
981 mutex_unlock(&pwm_lookup_lock);
982
983 if (!chosen)
984 return ERR_PTR(-ENODEV);
985
986 chip = pwmchip_find_by_name(chosen->provider);
987
988 /*
989 * If the lookup entry specifies a module, load the module and retry
990 * the PWM chip lookup. This can be used to work around driver load
991 * ordering issues if driver's can't be made to properly support the
992 * deferred probe mechanism.
993 */
994 if (!chip && chosen->module) {
995 err = request_module(chosen->module);
996 if (err == 0)
997 chip = pwmchip_find_by_name(chosen->provider);
998 }
999
1000 if (!chip)
1001 return ERR_PTR(-EPROBE_DEFER);
1002
1003 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1004 if (IS_ERR(pwm))
1005 return pwm;
1006
1007 dl = pwm_device_link_add(dev, pwm);
1008 if (IS_ERR(dl)) {
1009 pwm_free(pwm);
1010 return ERR_CAST(dl);
1011 }
1012
1013 pwm->args.period = chosen->period;
1014 pwm->args.polarity = chosen->polarity;
1015
1016 return pwm;
1017}
1018EXPORT_SYMBOL_GPL(pwm_get);
1019
1020/**
1021 * pwm_put() - release a PWM device
1022 * @pwm: PWM device
1023 */
1024void pwm_put(struct pwm_device *pwm)
1025{
1026 if (!pwm)
1027 return;
1028
1029 mutex_lock(&pwm_lock);
1030
1031 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1032 pr_warn("PWM device already freed\n");
1033 goto out;
1034 }
1035
1036 if (pwm->chip->ops->free)
1037 pwm->chip->ops->free(pwm->chip, pwm);
1038
1039 pwm_set_chip_data(pwm, NULL);
1040 pwm->label = NULL;
1041
1042 module_put(pwm->chip->ops->owner);
1043out:
1044 mutex_unlock(&pwm_lock);
1045}
1046EXPORT_SYMBOL_GPL(pwm_put);
1047
1048static void devm_pwm_release(void *pwm)
1049{
1050 pwm_put(pwm);
1051}
1052
1053/**
1054 * devm_pwm_get() - resource managed pwm_get()
1055 * @dev: device for PWM consumer
1056 * @con_id: consumer name
1057 *
1058 * This function performs like pwm_get() but the acquired PWM device will
1059 * automatically be released on driver detach.
1060 *
1061 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1062 * error code on failure.
1063 */
1064struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1065{
1066 struct pwm_device *pwm;
1067 int ret;
1068
1069 pwm = pwm_get(dev, con_id);
1070 if (IS_ERR(pwm))
1071 return pwm;
1072
1073 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1074 if (ret)
1075 return ERR_PTR(ret);
1076
1077 return pwm;
1078}
1079EXPORT_SYMBOL_GPL(devm_pwm_get);
1080
1081/**
1082 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
1083 * @dev: device for PWM consumer
1084 * @fwnode: firmware node to get the PWM from
1085 * @con_id: consumer name
1086 *
1087 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
1088 * acpi_pwm_get() for a detailed description.
1089 *
1090 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1091 * error code on failure.
1092 */
1093struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
1094 struct fwnode_handle *fwnode,
1095 const char *con_id)
1096{
1097 struct pwm_device *pwm = ERR_PTR(-ENODEV);
1098 int ret;
1099
1100 if (is_of_node(fwnode))
1101 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
1102 else if (is_acpi_node(fwnode))
1103 pwm = acpi_pwm_get(fwnode);
1104 if (IS_ERR(pwm))
1105 return pwm;
1106
1107 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
1108 if (ret)
1109 return ERR_PTR(ret);
1110
1111 return pwm;
1112}
1113EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
1114
1115#ifdef CONFIG_DEBUG_FS
1116static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
1117{
1118 unsigned int i;
1119
1120 for (i = 0; i < chip->npwm; i++) {
1121 struct pwm_device *pwm = &chip->pwms[i];
1122 struct pwm_state state;
1123
1124 pwm_get_state(pwm, &state);
1125
1126 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
1127
1128 if (test_bit(PWMF_REQUESTED, &pwm->flags))
1129 seq_puts(s, " requested");
1130
1131 if (state.enabled)
1132 seq_puts(s, " enabled");
1133
1134 seq_printf(s, " period: %llu ns", state.period);
1135 seq_printf(s, " duty: %llu ns", state.duty_cycle);
1136 seq_printf(s, " polarity: %s",
1137 state.polarity ? "inverse" : "normal");
1138
1139 if (state.usage_power)
1140 seq_puts(s, " usage_power");
1141
1142 seq_puts(s, "\n");
1143 }
1144}
1145
1146static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
1147{
1148 mutex_lock(&pwm_lock);
1149 s->private = "";
1150
1151 return seq_list_start(&pwm_chips, *pos);
1152}
1153
1154static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
1155{
1156 s->private = "\n";
1157
1158 return seq_list_next(v, &pwm_chips, pos);
1159}
1160
1161static void pwm_seq_stop(struct seq_file *s, void *v)
1162{
1163 mutex_unlock(&pwm_lock);
1164}
1165
1166static int pwm_seq_show(struct seq_file *s, void *v)
1167{
1168 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
1169
1170 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
1171 chip->dev->bus ? chip->dev->bus->name : "no-bus",
1172 dev_name(chip->dev), chip->npwm,
1173 (chip->npwm != 1) ? "s" : "");
1174
1175 pwm_dbg_show(chip, s);
1176
1177 return 0;
1178}
1179
1180static const struct seq_operations pwm_debugfs_sops = {
1181 .start = pwm_seq_start,
1182 .next = pwm_seq_next,
1183 .stop = pwm_seq_stop,
1184 .show = pwm_seq_show,
1185};
1186
1187DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
1188
1189static int __init pwm_debugfs_init(void)
1190{
1191 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
1192
1193 return 0;
1194}
1195subsys_initcall(pwm_debugfs_init);
1196#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#define DEFAULT_SYMBOL_NAMESPACE "PWM"
10
11#include <linux/acpi.h>
12#include <linux/module.h>
13#include <linux/idr.h>
14#include <linux/of.h>
15#include <linux/pwm.h>
16#include <linux/list.h>
17#include <linux/mutex.h>
18#include <linux/err.h>
19#include <linux/slab.h>
20#include <linux/device.h>
21#include <linux/debugfs.h>
22#include <linux/seq_file.h>
23
24#include <dt-bindings/pwm/pwm.h>
25
26#define CREATE_TRACE_POINTS
27#include <trace/events/pwm.h>
28
29/* protects access to pwm_chips */
30static DEFINE_MUTEX(pwm_lock);
31
32static DEFINE_IDR(pwm_chips);
33
34static void pwmchip_lock(struct pwm_chip *chip)
35{
36 if (chip->atomic)
37 spin_lock(&chip->atomic_lock);
38 else
39 mutex_lock(&chip->nonatomic_lock);
40}
41
42static void pwmchip_unlock(struct pwm_chip *chip)
43{
44 if (chip->atomic)
45 spin_unlock(&chip->atomic_lock);
46 else
47 mutex_unlock(&chip->nonatomic_lock);
48}
49
50DEFINE_GUARD(pwmchip, struct pwm_chip *, pwmchip_lock(_T), pwmchip_unlock(_T))
51
52static bool pwm_wf_valid(const struct pwm_waveform *wf)
53{
54 /*
55 * For now restrict waveforms to period_length_ns <= S64_MAX to provide
56 * some space for future extensions. One possibility is to simplify
57 * representing waveforms with inverted polarity using negative values
58 * somehow.
59 */
60 if (wf->period_length_ns > S64_MAX)
61 return false;
62
63 if (wf->duty_length_ns > wf->period_length_ns)
64 return false;
65
66 /*
67 * .duty_offset_ns is supposed to be smaller than .period_length_ns, apart
68 * from the corner case .duty_offset_ns == 0 && .period_length_ns == 0.
69 */
70 if (wf->duty_offset_ns && wf->duty_offset_ns >= wf->period_length_ns)
71 return false;
72
73 return true;
74}
75
76static void pwm_wf2state(const struct pwm_waveform *wf, struct pwm_state *state)
77{
78 if (wf->period_length_ns) {
79 if (wf->duty_length_ns + wf->duty_offset_ns < wf->period_length_ns)
80 *state = (struct pwm_state){
81 .enabled = true,
82 .polarity = PWM_POLARITY_NORMAL,
83 .period = wf->period_length_ns,
84 .duty_cycle = wf->duty_length_ns,
85 };
86 else
87 *state = (struct pwm_state){
88 .enabled = true,
89 .polarity = PWM_POLARITY_INVERSED,
90 .period = wf->period_length_ns,
91 .duty_cycle = wf->period_length_ns - wf->duty_length_ns,
92 };
93 } else {
94 *state = (struct pwm_state){
95 .enabled = false,
96 };
97 }
98}
99
100static void pwm_state2wf(const struct pwm_state *state, struct pwm_waveform *wf)
101{
102 if (state->enabled) {
103 if (state->polarity == PWM_POLARITY_NORMAL)
104 *wf = (struct pwm_waveform){
105 .period_length_ns = state->period,
106 .duty_length_ns = state->duty_cycle,
107 .duty_offset_ns = 0,
108 };
109 else
110 *wf = (struct pwm_waveform){
111 .period_length_ns = state->period,
112 .duty_length_ns = state->period - state->duty_cycle,
113 .duty_offset_ns = state->duty_cycle,
114 };
115 } else {
116 *wf = (struct pwm_waveform){
117 .period_length_ns = 0,
118 };
119 }
120}
121
122static int pwmwfcmp(const struct pwm_waveform *a, const struct pwm_waveform *b)
123{
124 if (a->period_length_ns > b->period_length_ns)
125 return 1;
126
127 if (a->period_length_ns < b->period_length_ns)
128 return -1;
129
130 if (a->duty_length_ns > b->duty_length_ns)
131 return 1;
132
133 if (a->duty_length_ns < b->duty_length_ns)
134 return -1;
135
136 if (a->duty_offset_ns > b->duty_offset_ns)
137 return 1;
138
139 if (a->duty_offset_ns < b->duty_offset_ns)
140 return -1;
141
142 return 0;
143}
144
145static bool pwm_check_rounding(const struct pwm_waveform *wf,
146 const struct pwm_waveform *wf_rounded)
147{
148 if (!wf->period_length_ns)
149 return true;
150
151 if (wf->period_length_ns < wf_rounded->period_length_ns)
152 return false;
153
154 if (wf->duty_length_ns < wf_rounded->duty_length_ns)
155 return false;
156
157 if (wf->duty_offset_ns < wf_rounded->duty_offset_ns)
158 return false;
159
160 return true;
161}
162
163static int __pwm_round_waveform_tohw(struct pwm_chip *chip, struct pwm_device *pwm,
164 const struct pwm_waveform *wf, void *wfhw)
165{
166 const struct pwm_ops *ops = chip->ops;
167 int ret;
168
169 ret = ops->round_waveform_tohw(chip, pwm, wf, wfhw);
170 trace_pwm_round_waveform_tohw(pwm, wf, wfhw, ret);
171
172 return ret;
173}
174
175static int __pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,
176 const void *wfhw, struct pwm_waveform *wf)
177{
178 const struct pwm_ops *ops = chip->ops;
179 int ret;
180
181 ret = ops->round_waveform_fromhw(chip, pwm, wfhw, wf);
182 trace_pwm_round_waveform_fromhw(pwm, wfhw, wf, ret);
183
184 return ret;
185}
186
187static int __pwm_read_waveform(struct pwm_chip *chip, struct pwm_device *pwm, void *wfhw)
188{
189 const struct pwm_ops *ops = chip->ops;
190 int ret;
191
192 ret = ops->read_waveform(chip, pwm, wfhw);
193 trace_pwm_read_waveform(pwm, wfhw, ret);
194
195 return ret;
196}
197
198static int __pwm_write_waveform(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw)
199{
200 const struct pwm_ops *ops = chip->ops;
201 int ret;
202
203 ret = ops->write_waveform(chip, pwm, wfhw);
204 trace_pwm_write_waveform(pwm, wfhw, ret);
205
206 return ret;
207}
208
209#define WFHWSIZE 20
210
211/**
212 * pwm_round_waveform_might_sleep - Query hardware capabilities
213 * Cannot be used in atomic context.
214 * @pwm: PWM device
215 * @wf: waveform to round and output parameter
216 *
217 * Typically a given waveform cannot be implemented exactly by hardware, e.g.
218 * because hardware only supports coarse period resolution or no duty_offset.
219 * This function returns the actually implemented waveform if you pass wf to
220 * pwm_set_waveform_might_sleep now.
221 *
222 * Note however that the world doesn't stop turning when you call it, so when
223 * doing
224 *
225 * pwm_round_waveform_might_sleep(mypwm, &wf);
226 * pwm_set_waveform_might_sleep(mypwm, &wf, true);
227 *
228 * the latter might fail, e.g. because an input clock changed its rate between
229 * these two calls and the waveform determined by
230 * pwm_round_waveform_might_sleep() cannot be implemented any more.
231 *
232 * Returns 0 on success, 1 if there is no valid hardware configuration matching
233 * the input waveform under the PWM rounding rules or a negative errno.
234 */
235int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf)
236{
237 struct pwm_chip *chip = pwm->chip;
238 const struct pwm_ops *ops = chip->ops;
239 struct pwm_waveform wf_req = *wf;
240 char wfhw[WFHWSIZE];
241 int ret_tohw, ret_fromhw;
242
243 BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
244
245 if (!pwmchip_supports_waveform(chip))
246 return -EOPNOTSUPP;
247
248 if (!pwm_wf_valid(wf))
249 return -EINVAL;
250
251 guard(pwmchip)(chip);
252
253 if (!chip->operational)
254 return -ENODEV;
255
256 ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, wfhw);
257 if (ret_tohw < 0)
258 return ret_tohw;
259
260 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_tohw > 1)
261 dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_tohw: requested %llu/%llu [+%llu], return value %d\n",
262 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_tohw);
263
264 ret_fromhw = __pwm_round_waveform_fromhw(chip, pwm, wfhw, wf);
265 if (ret_fromhw < 0)
266 return ret_fromhw;
267
268 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_fromhw > 0)
269 dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_fromhw: requested %llu/%llu [+%llu], return value %d\n",
270 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_tohw);
271
272 if (IS_ENABLED(CONFIG_PWM_DEBUG) &&
273 ret_tohw == 0 && !pwm_check_rounding(&wf_req, wf))
274 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",
275 wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns,
276 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns);
277
278 return ret_tohw;
279}
280EXPORT_SYMBOL_GPL(pwm_round_waveform_might_sleep);
281
282/**
283 * pwm_get_waveform_might_sleep - Query hardware about current configuration
284 * Cannot be used in atomic context.
285 * @pwm: PWM device
286 * @wf: output parameter
287 *
288 * Stores the current configuration of the PWM in @wf. Note this is the
289 * equivalent of pwm_get_state_hw() (and not pwm_get_state()) for pwm_waveform.
290 */
291int pwm_get_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf)
292{
293 struct pwm_chip *chip = pwm->chip;
294 const struct pwm_ops *ops = chip->ops;
295 char wfhw[WFHWSIZE];
296 int err;
297
298 BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
299
300 if (!pwmchip_supports_waveform(chip) || !ops->read_waveform)
301 return -EOPNOTSUPP;
302
303 guard(pwmchip)(chip);
304
305 if (!chip->operational)
306 return -ENODEV;
307
308 err = __pwm_read_waveform(chip, pwm, &wfhw);
309 if (err)
310 return err;
311
312 return __pwm_round_waveform_fromhw(chip, pwm, &wfhw, wf);
313}
314EXPORT_SYMBOL_GPL(pwm_get_waveform_might_sleep);
315
316/* Called with the pwmchip lock held */
317static int __pwm_set_waveform(struct pwm_device *pwm,
318 const struct pwm_waveform *wf,
319 bool exact)
320{
321 struct pwm_chip *chip = pwm->chip;
322 const struct pwm_ops *ops = chip->ops;
323 char wfhw[WFHWSIZE];
324 struct pwm_waveform wf_rounded;
325 int err;
326
327 BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
328
329 if (!pwmchip_supports_waveform(chip))
330 return -EOPNOTSUPP;
331
332 if (!pwm_wf_valid(wf))
333 return -EINVAL;
334
335 err = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);
336 if (err)
337 return err;
338
339 if ((IS_ENABLED(CONFIG_PWM_DEBUG) || exact) && wf->period_length_ns) {
340 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);
341 if (err)
342 return err;
343
344 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !pwm_check_rounding(wf, &wf_rounded))
345 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",
346 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
347 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
348
349 if (exact && pwmwfcmp(wf, &wf_rounded)) {
350 dev_dbg(&chip->dev, "Requested no rounding, but %llu/%llu [+%llu] -> %llu/%llu [+%llu]\n",
351 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
352 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
353
354 return 1;
355 }
356 }
357
358 err = __pwm_write_waveform(chip, pwm, &wfhw);
359 if (err)
360 return err;
361
362 /* update .state */
363 pwm_wf2state(wf, &pwm->state);
364
365 if (IS_ENABLED(CONFIG_PWM_DEBUG) && ops->read_waveform && wf->period_length_ns) {
366 struct pwm_waveform wf_set;
367
368 err = __pwm_read_waveform(chip, pwm, &wfhw);
369 if (err)
370 /* maybe ignore? */
371 return err;
372
373 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_set);
374 if (err)
375 /* maybe ignore? */
376 return err;
377
378 if (pwmwfcmp(&wf_set, &wf_rounded) != 0)
379 dev_err(&chip->dev,
380 "Unexpected setting: requested %llu/%llu [+%llu], expected %llu/%llu [+%llu], set %llu/%llu [+%llu]\n",
381 wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
382 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns,
383 wf_set.duty_length_ns, wf_set.period_length_ns, wf_set.duty_offset_ns);
384 }
385 return 0;
386}
387
388/**
389 * pwm_set_waveform_might_sleep - Apply a new waveform
390 * Cannot be used in atomic context.
391 * @pwm: PWM device
392 * @wf: The waveform to apply
393 * @exact: If true no rounding is allowed
394 *
395 * Typically a requested waveform cannot be implemented exactly, e.g. because
396 * you requested .period_length_ns = 100 ns, but the hardware can only set
397 * periods that are a multiple of 8.5 ns. With that hardware passing exact =
398 * true results in pwm_set_waveform_might_sleep() failing and returning 1. If
399 * exact = false you get a period of 93.5 ns (i.e. the biggest period not bigger
400 * than the requested value).
401 * Note that even with exact = true, some rounding by less than 1 is
402 * possible/needed. In the above example requesting .period_length_ns = 94 and
403 * exact = true, you get the hardware configured with period = 93.5 ns.
404 */
405int pwm_set_waveform_might_sleep(struct pwm_device *pwm,
406 const struct pwm_waveform *wf, bool exact)
407{
408 struct pwm_chip *chip = pwm->chip;
409 int err;
410
411 might_sleep();
412
413 guard(pwmchip)(chip);
414
415 if (!chip->operational)
416 return -ENODEV;
417
418 if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) {
419 /*
420 * Catch any drivers that have been marked as atomic but
421 * that will sleep anyway.
422 */
423 non_block_start();
424 err = __pwm_set_waveform(pwm, wf, exact);
425 non_block_end();
426 } else {
427 err = __pwm_set_waveform(pwm, wf, exact);
428 }
429
430 return err;
431}
432EXPORT_SYMBOL_GPL(pwm_set_waveform_might_sleep);
433
434static void pwm_apply_debug(struct pwm_device *pwm,
435 const struct pwm_state *state)
436{
437 struct pwm_state *last = &pwm->last;
438 struct pwm_chip *chip = pwm->chip;
439 struct pwm_state s1 = { 0 }, s2 = { 0 };
440 int err;
441
442 if (!IS_ENABLED(CONFIG_PWM_DEBUG))
443 return;
444
445 /* No reasonable diagnosis possible without .get_state() */
446 if (!chip->ops->get_state)
447 return;
448
449 /*
450 * *state was just applied. Read out the hardware state and do some
451 * checks.
452 */
453
454 err = chip->ops->get_state(chip, pwm, &s1);
455 trace_pwm_get(pwm, &s1, err);
456 if (err)
457 /* If that failed there isn't much to debug */
458 return;
459
460 /*
461 * The lowlevel driver either ignored .polarity (which is a bug) or as
462 * best effort inverted .polarity and fixed .duty_cycle respectively.
463 * Undo this inversion and fixup for further tests.
464 */
465 if (s1.enabled && s1.polarity != state->polarity) {
466 s2.polarity = state->polarity;
467 s2.duty_cycle = s1.period - s1.duty_cycle;
468 s2.period = s1.period;
469 s2.enabled = s1.enabled;
470 } else {
471 s2 = s1;
472 }
473
474 if (s2.polarity != state->polarity &&
475 state->duty_cycle < state->period)
476 dev_warn(pwmchip_parent(chip), ".apply ignored .polarity\n");
477
478 if (state->enabled && s2.enabled &&
479 last->polarity == state->polarity &&
480 last->period > s2.period &&
481 last->period <= state->period)
482 dev_warn(pwmchip_parent(chip),
483 ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n",
484 state->period, s2.period, last->period);
485
486 /*
487 * Rounding period up is fine only if duty_cycle is 0 then, because a
488 * flat line doesn't have a characteristic period.
489 */
490 if (state->enabled && s2.enabled && state->period < s2.period && s2.duty_cycle)
491 dev_warn(pwmchip_parent(chip),
492 ".apply is supposed to round down period (requested: %llu, applied: %llu)\n",
493 state->period, s2.period);
494
495 if (state->enabled &&
496 last->polarity == state->polarity &&
497 last->period == s2.period &&
498 last->duty_cycle > s2.duty_cycle &&
499 last->duty_cycle <= state->duty_cycle)
500 dev_warn(pwmchip_parent(chip),
501 ".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n",
502 state->duty_cycle, state->period,
503 s2.duty_cycle, s2.period,
504 last->duty_cycle, last->period);
505
506 if (state->enabled && s2.enabled && state->duty_cycle < s2.duty_cycle)
507 dev_warn(pwmchip_parent(chip),
508 ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n",
509 state->duty_cycle, state->period,
510 s2.duty_cycle, s2.period);
511
512 if (!state->enabled && s2.enabled && s2.duty_cycle > 0)
513 dev_warn(pwmchip_parent(chip),
514 "requested disabled, but yielded enabled with duty > 0\n");
515
516 /* reapply the state that the driver reported being configured. */
517 err = chip->ops->apply(chip, pwm, &s1);
518 trace_pwm_apply(pwm, &s1, err);
519 if (err) {
520 *last = s1;
521 dev_err(pwmchip_parent(chip), "failed to reapply current setting\n");
522 return;
523 }
524
525 *last = (struct pwm_state){ 0 };
526 err = chip->ops->get_state(chip, pwm, last);
527 trace_pwm_get(pwm, last, err);
528 if (err)
529 return;
530
531 /* reapplication of the current state should give an exact match */
532 if (s1.enabled != last->enabled ||
533 s1.polarity != last->polarity ||
534 (s1.enabled && s1.period != last->period) ||
535 (s1.enabled && s1.duty_cycle != last->duty_cycle)) {
536 dev_err(pwmchip_parent(chip),
537 ".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n",
538 s1.enabled, s1.polarity, s1.duty_cycle, s1.period,
539 last->enabled, last->polarity, last->duty_cycle,
540 last->period);
541 }
542}
543
544static bool pwm_state_valid(const struct pwm_state *state)
545{
546 /*
547 * For a disabled state all other state description is irrelevant and
548 * and supposed to be ignored. So also ignore any strange values and
549 * consider the state ok.
550 */
551 if (state->enabled)
552 return true;
553
554 if (!state->period)
555 return false;
556
557 if (state->duty_cycle > state->period)
558 return false;
559
560 return true;
561}
562
563/**
564 * __pwm_apply() - atomically apply a new state to a PWM device
565 * @pwm: PWM device
566 * @state: new state to apply
567 */
568static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state)
569{
570 struct pwm_chip *chip;
571 const struct pwm_ops *ops;
572 int err;
573
574 if (!pwm || !state)
575 return -EINVAL;
576
577 if (!pwm_state_valid(state)) {
578 /*
579 * Allow to transition from one invalid state to another.
580 * This ensures that you can e.g. change the polarity while
581 * the period is zero. (This happens on stm32 when the hardware
582 * is in its poweron default state.) This greatly simplifies
583 * working with the sysfs API where you can only change one
584 * parameter at a time.
585 */
586 if (!pwm_state_valid(&pwm->state)) {
587 pwm->state = *state;
588 return 0;
589 }
590
591 return -EINVAL;
592 }
593
594 chip = pwm->chip;
595 ops = chip->ops;
596
597 if (state->period == pwm->state.period &&
598 state->duty_cycle == pwm->state.duty_cycle &&
599 state->polarity == pwm->state.polarity &&
600 state->enabled == pwm->state.enabled &&
601 state->usage_power == pwm->state.usage_power)
602 return 0;
603
604 if (pwmchip_supports_waveform(chip)) {
605 struct pwm_waveform wf;
606 char wfhw[WFHWSIZE];
607
608 BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
609
610 pwm_state2wf(state, &wf);
611
612 /*
613 * The rounding is wrong here for states with inverted polarity.
614 * While .apply() rounds down duty_cycle (which represents the
615 * time from the start of the period to the inner edge),
616 * .round_waveform_tohw() rounds down the time the PWM is high.
617 * Can be fixed if the need arises, until reported otherwise
618 * let's assume that consumers don't care.
619 */
620
621 err = __pwm_round_waveform_tohw(chip, pwm, &wf, &wfhw);
622 if (err) {
623 if (err > 0)
624 /*
625 * This signals an invalid request, typically
626 * the requested period (or duty_offset) is
627 * smaller than possible with the hardware.
628 */
629 return -EINVAL;
630
631 return err;
632 }
633
634 if (IS_ENABLED(CONFIG_PWM_DEBUG)) {
635 struct pwm_waveform wf_rounded;
636
637 err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);
638 if (err)
639 return err;
640
641 if (!pwm_check_rounding(&wf, &wf_rounded))
642 dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",
643 wf.duty_length_ns, wf.period_length_ns, wf.duty_offset_ns,
644 wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
645 }
646
647 err = __pwm_write_waveform(chip, pwm, &wfhw);
648 if (err)
649 return err;
650
651 pwm->state = *state;
652
653 } else {
654 err = ops->apply(chip, pwm, state);
655 trace_pwm_apply(pwm, state, err);
656 if (err)
657 return err;
658
659 pwm->state = *state;
660
661 /*
662 * only do this after pwm->state was applied as some
663 * implementations of .get_state() depend on this
664 */
665 pwm_apply_debug(pwm, state);
666 }
667
668 return 0;
669}
670
671/**
672 * pwm_apply_might_sleep() - atomically apply a new state to a PWM device
673 * Cannot be used in atomic context.
674 * @pwm: PWM device
675 * @state: new state to apply
676 */
677int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state)
678{
679 int err;
680 struct pwm_chip *chip = pwm->chip;
681
682 /*
683 * Some lowlevel driver's implementations of .apply() make use of
684 * mutexes, also with some drivers only returning when the new
685 * configuration is active calling pwm_apply_might_sleep() from atomic context
686 * is a bad idea. So make it explicit that calling this function might
687 * sleep.
688 */
689 might_sleep();
690
691 guard(pwmchip)(chip);
692
693 if (!chip->operational)
694 return -ENODEV;
695
696 if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) {
697 /*
698 * Catch any drivers that have been marked as atomic but
699 * that will sleep anyway.
700 */
701 non_block_start();
702 err = __pwm_apply(pwm, state);
703 non_block_end();
704 } else {
705 err = __pwm_apply(pwm, state);
706 }
707
708 return err;
709}
710EXPORT_SYMBOL_GPL(pwm_apply_might_sleep);
711
712/**
713 * pwm_apply_atomic() - apply a new state to a PWM device from atomic context
714 * Not all PWM devices support this function, check with pwm_might_sleep().
715 * @pwm: PWM device
716 * @state: new state to apply
717 */
718int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state)
719{
720 struct pwm_chip *chip = pwm->chip;
721
722 WARN_ONCE(!chip->atomic,
723 "sleeping PWM driver used in atomic context\n");
724
725 guard(pwmchip)(chip);
726
727 if (!chip->operational)
728 return -ENODEV;
729
730 return __pwm_apply(pwm, state);
731}
732EXPORT_SYMBOL_GPL(pwm_apply_atomic);
733
734/**
735 * pwm_get_state_hw() - get the current PWM state from hardware
736 * @pwm: PWM device
737 * @state: state to fill with the current PWM state
738 *
739 * Similar to pwm_get_state() but reads the current PWM state from hardware
740 * instead of the requested state.
741 *
742 * Returns: 0 on success or a negative error code on failure.
743 * Context: May sleep.
744 */
745int pwm_get_state_hw(struct pwm_device *pwm, struct pwm_state *state)
746{
747 struct pwm_chip *chip = pwm->chip;
748 const struct pwm_ops *ops = chip->ops;
749 int ret = -EOPNOTSUPP;
750
751 might_sleep();
752
753 guard(pwmchip)(chip);
754
755 if (!chip->operational)
756 return -ENODEV;
757
758 if (pwmchip_supports_waveform(chip) && ops->read_waveform) {
759 char wfhw[WFHWSIZE];
760 struct pwm_waveform wf;
761
762 BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
763
764 ret = __pwm_read_waveform(chip, pwm, &wfhw);
765 if (ret)
766 return ret;
767
768 ret = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf);
769 if (ret)
770 return ret;
771
772 pwm_wf2state(&wf, state);
773
774 } else if (ops->get_state) {
775 ret = ops->get_state(chip, pwm, state);
776 trace_pwm_get(pwm, state, ret);
777 }
778
779 return ret;
780}
781EXPORT_SYMBOL_GPL(pwm_get_state_hw);
782
783/**
784 * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
785 * @pwm: PWM device
786 *
787 * This function will adjust the PWM config to the PWM arguments provided
788 * by the DT or PWM lookup table. This is particularly useful to adapt
789 * the bootloader config to the Linux one.
790 */
791int pwm_adjust_config(struct pwm_device *pwm)
792{
793 struct pwm_state state;
794 struct pwm_args pargs;
795
796 pwm_get_args(pwm, &pargs);
797 pwm_get_state(pwm, &state);
798
799 /*
800 * If the current period is zero it means that either the PWM driver
801 * does not support initial state retrieval or the PWM has not yet
802 * been configured.
803 *
804 * In either case, we setup the new period and polarity, and assign a
805 * duty cycle of 0.
806 */
807 if (!state.period) {
808 state.duty_cycle = 0;
809 state.period = pargs.period;
810 state.polarity = pargs.polarity;
811
812 return pwm_apply_might_sleep(pwm, &state);
813 }
814
815 /*
816 * Adjust the PWM duty cycle/period based on the period value provided
817 * in PWM args.
818 */
819 if (pargs.period != state.period) {
820 u64 dutycycle = (u64)state.duty_cycle * pargs.period;
821
822 do_div(dutycycle, state.period);
823 state.duty_cycle = dutycycle;
824 state.period = pargs.period;
825 }
826
827 /*
828 * If the polarity changed, we should also change the duty cycle.
829 */
830 if (pargs.polarity != state.polarity) {
831 state.polarity = pargs.polarity;
832 state.duty_cycle = state.period - state.duty_cycle;
833 }
834
835 return pwm_apply_might_sleep(pwm, &state);
836}
837EXPORT_SYMBOL_GPL(pwm_adjust_config);
838
839/**
840 * pwm_capture() - capture and report a PWM signal
841 * @pwm: PWM device
842 * @result: structure to fill with capture result
843 * @timeout: time to wait, in milliseconds, before giving up on capture
844 *
845 * Returns: 0 on success or a negative error code on failure.
846 */
847static int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
848 unsigned long timeout)
849{
850 struct pwm_chip *chip = pwm->chip;
851 const struct pwm_ops *ops = chip->ops;
852
853 if (!ops->capture)
854 return -ENOSYS;
855
856 /*
857 * Holding the pwm_lock is probably not needed. If you use pwm_capture()
858 * and you're interested to speed it up, please convince yourself it's
859 * really not needed, test and then suggest a patch on the mailing list.
860 */
861 guard(mutex)(&pwm_lock);
862
863 guard(pwmchip)(chip);
864
865 if (!chip->operational)
866 return -ENODEV;
867
868 return ops->capture(chip, pwm, result, timeout);
869}
870
871static struct pwm_chip *pwmchip_find_by_name(const char *name)
872{
873 struct pwm_chip *chip;
874 unsigned long id, tmp;
875
876 if (!name)
877 return NULL;
878
879 guard(mutex)(&pwm_lock);
880
881 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) {
882 if (device_match_name(pwmchip_parent(chip), name))
883 return chip;
884 }
885
886 return NULL;
887}
888
889static int pwm_device_request(struct pwm_device *pwm, const char *label)
890{
891 int err;
892 struct pwm_chip *chip = pwm->chip;
893 const struct pwm_ops *ops = chip->ops;
894
895 if (test_bit(PWMF_REQUESTED, &pwm->flags))
896 return -EBUSY;
897
898 /*
899 * This function is called while holding pwm_lock. As .operational only
900 * changes while holding this lock, checking it here without holding the
901 * chip lock is fine.
902 */
903 if (!chip->operational)
904 return -ENODEV;
905
906 if (!try_module_get(chip->owner))
907 return -ENODEV;
908
909 if (!get_device(&chip->dev)) {
910 err = -ENODEV;
911 goto err_get_device;
912 }
913
914 if (ops->request) {
915 err = ops->request(chip, pwm);
916 if (err) {
917 put_device(&chip->dev);
918err_get_device:
919 module_put(chip->owner);
920 return err;
921 }
922 }
923
924 if (ops->read_waveform || ops->get_state) {
925 /*
926 * Zero-initialize state because most drivers are unaware of
927 * .usage_power. The other members of state are supposed to be
928 * set by lowlevel drivers. We still initialize the whole
929 * structure for simplicity even though this might paper over
930 * faulty implementations of .get_state().
931 */
932 struct pwm_state state = { 0, };
933
934 err = pwm_get_state_hw(pwm, &state);
935 if (!err)
936 pwm->state = state;
937
938 if (IS_ENABLED(CONFIG_PWM_DEBUG))
939 pwm->last = pwm->state;
940 }
941
942 set_bit(PWMF_REQUESTED, &pwm->flags);
943 pwm->label = label;
944
945 return 0;
946}
947
948/**
949 * pwm_request_from_chip() - request a PWM device relative to a PWM chip
950 * @chip: PWM chip
951 * @index: per-chip index of the PWM to request
952 * @label: a literal description string of this PWM
953 *
954 * Returns: A pointer to the PWM device at the given index of the given PWM
955 * chip. A negative error code is returned if the index is not valid for the
956 * specified PWM chip or if the PWM device cannot be requested.
957 */
958static struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
959 unsigned int index,
960 const char *label)
961{
962 struct pwm_device *pwm;
963 int err;
964
965 if (!chip || index >= chip->npwm)
966 return ERR_PTR(-EINVAL);
967
968 guard(mutex)(&pwm_lock);
969
970 pwm = &chip->pwms[index];
971
972 err = pwm_device_request(pwm, label);
973 if (err < 0)
974 return ERR_PTR(err);
975
976 return pwm;
977}
978
979struct pwm_device *
980of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args)
981{
982 struct pwm_device *pwm;
983
984 /* period in the second cell and flags in the third cell are optional */
985 if (args->args_count < 1)
986 return ERR_PTR(-EINVAL);
987
988 pwm = pwm_request_from_chip(chip, args->args[0], NULL);
989 if (IS_ERR(pwm))
990 return pwm;
991
992 if (args->args_count > 1)
993 pwm->args.period = args->args[1];
994
995 pwm->args.polarity = PWM_POLARITY_NORMAL;
996 if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
997 pwm->args.polarity = PWM_POLARITY_INVERSED;
998
999 return pwm;
1000}
1001EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
1002
1003struct pwm_device *
1004of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
1005{
1006 struct pwm_device *pwm;
1007
1008 pwm = pwm_request_from_chip(chip, 0, NULL);
1009 if (IS_ERR(pwm))
1010 return pwm;
1011
1012 if (args->args_count > 0)
1013 pwm->args.period = args->args[0];
1014
1015 pwm->args.polarity = PWM_POLARITY_NORMAL;
1016 if (args->args_count > 1 && args->args[1] & PWM_POLARITY_INVERTED)
1017 pwm->args.polarity = PWM_POLARITY_INVERSED;
1018
1019 return pwm;
1020}
1021EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
1022
1023struct pwm_export {
1024 struct device pwm_dev;
1025 struct pwm_device *pwm;
1026 struct mutex lock;
1027 struct pwm_state suspend;
1028};
1029
1030static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)
1031{
1032 return container_of(pwmchip_dev, struct pwm_chip, dev);
1033}
1034
1035static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
1036{
1037 return container_of(pwm_dev, struct pwm_export, pwm_dev);
1038}
1039
1040static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev)
1041{
1042 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1043
1044 return export->pwm;
1045}
1046
1047static ssize_t period_show(struct device *pwm_dev,
1048 struct device_attribute *attr,
1049 char *buf)
1050{
1051 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1052 struct pwm_state state;
1053
1054 pwm_get_state(pwm, &state);
1055
1056 return sysfs_emit(buf, "%llu\n", state.period);
1057}
1058
1059static ssize_t period_store(struct device *pwm_dev,
1060 struct device_attribute *attr,
1061 const char *buf, size_t size)
1062{
1063 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1064 struct pwm_device *pwm = export->pwm;
1065 struct pwm_state state;
1066 u64 val;
1067 int ret;
1068
1069 ret = kstrtou64(buf, 0, &val);
1070 if (ret)
1071 return ret;
1072
1073 guard(mutex)(&export->lock);
1074
1075 pwm_get_state(pwm, &state);
1076 state.period = val;
1077 ret = pwm_apply_might_sleep(pwm, &state);
1078
1079 return ret ? : size;
1080}
1081
1082static ssize_t duty_cycle_show(struct device *pwm_dev,
1083 struct device_attribute *attr,
1084 char *buf)
1085{
1086 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1087 struct pwm_state state;
1088
1089 pwm_get_state(pwm, &state);
1090
1091 return sysfs_emit(buf, "%llu\n", state.duty_cycle);
1092}
1093
1094static ssize_t duty_cycle_store(struct device *pwm_dev,
1095 struct device_attribute *attr,
1096 const char *buf, size_t size)
1097{
1098 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1099 struct pwm_device *pwm = export->pwm;
1100 struct pwm_state state;
1101 u64 val;
1102 int ret;
1103
1104 ret = kstrtou64(buf, 0, &val);
1105 if (ret)
1106 return ret;
1107
1108 guard(mutex)(&export->lock);
1109
1110 pwm_get_state(pwm, &state);
1111 state.duty_cycle = val;
1112 ret = pwm_apply_might_sleep(pwm, &state);
1113
1114 return ret ? : size;
1115}
1116
1117static ssize_t enable_show(struct device *pwm_dev,
1118 struct device_attribute *attr,
1119 char *buf)
1120{
1121 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1122 struct pwm_state state;
1123
1124 pwm_get_state(pwm, &state);
1125
1126 return sysfs_emit(buf, "%d\n", state.enabled);
1127}
1128
1129static ssize_t enable_store(struct device *pwm_dev,
1130 struct device_attribute *attr,
1131 const char *buf, size_t size)
1132{
1133 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1134 struct pwm_device *pwm = export->pwm;
1135 struct pwm_state state;
1136 int val, ret;
1137
1138 ret = kstrtoint(buf, 0, &val);
1139 if (ret)
1140 return ret;
1141
1142 guard(mutex)(&export->lock);
1143
1144 pwm_get_state(pwm, &state);
1145
1146 switch (val) {
1147 case 0:
1148 state.enabled = false;
1149 break;
1150 case 1:
1151 state.enabled = true;
1152 break;
1153 default:
1154 return -EINVAL;
1155 }
1156
1157 ret = pwm_apply_might_sleep(pwm, &state);
1158
1159 return ret ? : size;
1160}
1161
1162static ssize_t polarity_show(struct device *pwm_dev,
1163 struct device_attribute *attr,
1164 char *buf)
1165{
1166 const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1167 const char *polarity = "unknown";
1168 struct pwm_state state;
1169
1170 pwm_get_state(pwm, &state);
1171
1172 switch (state.polarity) {
1173 case PWM_POLARITY_NORMAL:
1174 polarity = "normal";
1175 break;
1176
1177 case PWM_POLARITY_INVERSED:
1178 polarity = "inversed";
1179 break;
1180 }
1181
1182 return sysfs_emit(buf, "%s\n", polarity);
1183}
1184
1185static ssize_t polarity_store(struct device *pwm_dev,
1186 struct device_attribute *attr,
1187 const char *buf, size_t size)
1188{
1189 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1190 struct pwm_device *pwm = export->pwm;
1191 enum pwm_polarity polarity;
1192 struct pwm_state state;
1193 int ret;
1194
1195 if (sysfs_streq(buf, "normal"))
1196 polarity = PWM_POLARITY_NORMAL;
1197 else if (sysfs_streq(buf, "inversed"))
1198 polarity = PWM_POLARITY_INVERSED;
1199 else
1200 return -EINVAL;
1201
1202 guard(mutex)(&export->lock);
1203
1204 pwm_get_state(pwm, &state);
1205 state.polarity = polarity;
1206 ret = pwm_apply_might_sleep(pwm, &state);
1207
1208 return ret ? : size;
1209}
1210
1211static ssize_t capture_show(struct device *pwm_dev,
1212 struct device_attribute *attr,
1213 char *buf)
1214{
1215 struct pwm_device *pwm = pwm_from_dev(pwm_dev);
1216 struct pwm_capture result;
1217 int ret;
1218
1219 ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
1220 if (ret)
1221 return ret;
1222
1223 return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle);
1224}
1225
1226static DEVICE_ATTR_RW(period);
1227static DEVICE_ATTR_RW(duty_cycle);
1228static DEVICE_ATTR_RW(enable);
1229static DEVICE_ATTR_RW(polarity);
1230static DEVICE_ATTR_RO(capture);
1231
1232static struct attribute *pwm_attrs[] = {
1233 &dev_attr_period.attr,
1234 &dev_attr_duty_cycle.attr,
1235 &dev_attr_enable.attr,
1236 &dev_attr_polarity.attr,
1237 &dev_attr_capture.attr,
1238 NULL
1239};
1240ATTRIBUTE_GROUPS(pwm);
1241
1242static void pwm_export_release(struct device *pwm_dev)
1243{
1244 struct pwm_export *export = pwmexport_from_dev(pwm_dev);
1245
1246 kfree(export);
1247}
1248
1249static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
1250{
1251 struct pwm_export *export;
1252 char *pwm_prop[2];
1253 int ret;
1254
1255 if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
1256 return -EBUSY;
1257
1258 export = kzalloc(sizeof(*export), GFP_KERNEL);
1259 if (!export) {
1260 clear_bit(PWMF_EXPORTED, &pwm->flags);
1261 return -ENOMEM;
1262 }
1263
1264 export->pwm = pwm;
1265 mutex_init(&export->lock);
1266
1267 export->pwm_dev.release = pwm_export_release;
1268 export->pwm_dev.parent = pwmchip_dev;
1269 export->pwm_dev.devt = MKDEV(0, 0);
1270 export->pwm_dev.groups = pwm_groups;
1271 dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm);
1272
1273 ret = device_register(&export->pwm_dev);
1274 if (ret) {
1275 clear_bit(PWMF_EXPORTED, &pwm->flags);
1276 put_device(&export->pwm_dev);
1277 export = NULL;
1278 return ret;
1279 }
1280 pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
1281 pwm_prop[1] = NULL;
1282 kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
1283 kfree(pwm_prop[0]);
1284
1285 return 0;
1286}
1287
1288static int pwm_unexport_match(struct device *pwm_dev, void *data)
1289{
1290 return pwm_from_dev(pwm_dev) == data;
1291}
1292
1293static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm)
1294{
1295 struct device *pwm_dev;
1296 char *pwm_prop[2];
1297
1298 if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
1299 return -ENODEV;
1300
1301 pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
1302 if (!pwm_dev)
1303 return -ENODEV;
1304
1305 pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
1306 pwm_prop[1] = NULL;
1307 kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
1308 kfree(pwm_prop[0]);
1309
1310 /* for device_find_child() */
1311 put_device(pwm_dev);
1312 device_unregister(pwm_dev);
1313 pwm_put(pwm);
1314
1315 return 0;
1316}
1317
1318static ssize_t export_store(struct device *pwmchip_dev,
1319 struct device_attribute *attr,
1320 const char *buf, size_t len)
1321{
1322 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1323 struct pwm_device *pwm;
1324 unsigned int hwpwm;
1325 int ret;
1326
1327 ret = kstrtouint(buf, 0, &hwpwm);
1328 if (ret < 0)
1329 return ret;
1330
1331 if (hwpwm >= chip->npwm)
1332 return -ENODEV;
1333
1334 pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
1335 if (IS_ERR(pwm))
1336 return PTR_ERR(pwm);
1337
1338 ret = pwm_export_child(pwmchip_dev, pwm);
1339 if (ret < 0)
1340 pwm_put(pwm);
1341
1342 return ret ? : len;
1343}
1344static DEVICE_ATTR_WO(export);
1345
1346static ssize_t unexport_store(struct device *pwmchip_dev,
1347 struct device_attribute *attr,
1348 const char *buf, size_t len)
1349{
1350 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1351 unsigned int hwpwm;
1352 int ret;
1353
1354 ret = kstrtouint(buf, 0, &hwpwm);
1355 if (ret < 0)
1356 return ret;
1357
1358 if (hwpwm >= chip->npwm)
1359 return -ENODEV;
1360
1361 ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]);
1362
1363 return ret ? : len;
1364}
1365static DEVICE_ATTR_WO(unexport);
1366
1367static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr,
1368 char *buf)
1369{
1370 const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1371
1372 return sysfs_emit(buf, "%u\n", chip->npwm);
1373}
1374static DEVICE_ATTR_RO(npwm);
1375
1376static struct attribute *pwm_chip_attrs[] = {
1377 &dev_attr_export.attr,
1378 &dev_attr_unexport.attr,
1379 &dev_attr_npwm.attr,
1380 NULL,
1381};
1382ATTRIBUTE_GROUPS(pwm_chip);
1383
1384/* takes export->lock on success */
1385static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev,
1386 struct pwm_device *pwm,
1387 struct pwm_state *state)
1388{
1389 struct device *pwm_dev;
1390 struct pwm_export *export;
1391
1392 if (!test_bit(PWMF_EXPORTED, &pwm->flags))
1393 return NULL;
1394
1395 pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
1396 if (!pwm_dev)
1397 return NULL;
1398
1399 export = pwmexport_from_dev(pwm_dev);
1400 put_device(pwm_dev); /* for device_find_child() */
1401
1402 mutex_lock(&export->lock);
1403 pwm_get_state(pwm, state);
1404
1405 return export;
1406}
1407
1408static int pwm_class_apply_state(struct pwm_export *export,
1409 struct pwm_device *pwm,
1410 struct pwm_state *state)
1411{
1412 int ret = pwm_apply_might_sleep(pwm, state);
1413
1414 /* release lock taken in pwm_class_get_state */
1415 mutex_unlock(&export->lock);
1416
1417 return ret;
1418}
1419
1420static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm)
1421{
1422 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1423 unsigned int i;
1424 int ret = 0;
1425
1426 for (i = 0; i < npwm; i++) {
1427 struct pwm_device *pwm = &chip->pwms[i];
1428 struct pwm_state state;
1429 struct pwm_export *export;
1430
1431 export = pwm_class_get_state(pwmchip_dev, pwm, &state);
1432 if (!export)
1433 continue;
1434
1435 /* If pwmchip was not enabled before suspend, do nothing. */
1436 if (!export->suspend.enabled) {
1437 /* release lock taken in pwm_class_get_state */
1438 mutex_unlock(&export->lock);
1439 continue;
1440 }
1441
1442 state.enabled = export->suspend.enabled;
1443 ret = pwm_class_apply_state(export, pwm, &state);
1444 if (ret < 0)
1445 break;
1446 }
1447
1448 return ret;
1449}
1450
1451static int pwm_class_suspend(struct device *pwmchip_dev)
1452{
1453 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1454 unsigned int i;
1455 int ret = 0;
1456
1457 for (i = 0; i < chip->npwm; i++) {
1458 struct pwm_device *pwm = &chip->pwms[i];
1459 struct pwm_state state;
1460 struct pwm_export *export;
1461
1462 export = pwm_class_get_state(pwmchip_dev, pwm, &state);
1463 if (!export)
1464 continue;
1465
1466 /*
1467 * If pwmchip was not enabled before suspend, save
1468 * state for resume time and do nothing else.
1469 */
1470 export->suspend = state;
1471 if (!state.enabled) {
1472 /* release lock taken in pwm_class_get_state */
1473 mutex_unlock(&export->lock);
1474 continue;
1475 }
1476
1477 state.enabled = false;
1478 ret = pwm_class_apply_state(export, pwm, &state);
1479 if (ret < 0) {
1480 /*
1481 * roll back the PWM devices that were disabled by
1482 * this suspend function.
1483 */
1484 pwm_class_resume_npwm(pwmchip_dev, i);
1485 break;
1486 }
1487 }
1488
1489 return ret;
1490}
1491
1492static int pwm_class_resume(struct device *pwmchip_dev)
1493{
1494 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1495
1496 return pwm_class_resume_npwm(pwmchip_dev, chip->npwm);
1497}
1498
1499static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
1500
1501static struct class pwm_class = {
1502 .name = "pwm",
1503 .dev_groups = pwm_chip_groups,
1504 .pm = pm_sleep_ptr(&pwm_class_pm_ops),
1505};
1506
1507static void pwmchip_sysfs_unexport(struct pwm_chip *chip)
1508{
1509 unsigned int i;
1510
1511 for (i = 0; i < chip->npwm; i++) {
1512 struct pwm_device *pwm = &chip->pwms[i];
1513
1514 if (test_bit(PWMF_EXPORTED, &pwm->flags))
1515 pwm_unexport_child(&chip->dev, pwm);
1516 }
1517}
1518
1519#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
1520
1521static void *pwmchip_priv(struct pwm_chip *chip)
1522{
1523 return (void *)chip + ALIGN(struct_size(chip, pwms, chip->npwm), PWMCHIP_ALIGN);
1524}
1525
1526/* This is the counterpart to pwmchip_alloc() */
1527void pwmchip_put(struct pwm_chip *chip)
1528{
1529 put_device(&chip->dev);
1530}
1531EXPORT_SYMBOL_GPL(pwmchip_put);
1532
1533static void pwmchip_release(struct device *pwmchip_dev)
1534{
1535 struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
1536
1537 kfree(chip);
1538}
1539
1540struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
1541{
1542 struct pwm_chip *chip;
1543 struct device *pwmchip_dev;
1544 size_t alloc_size;
1545 unsigned int i;
1546
1547 alloc_size = size_add(ALIGN(struct_size(chip, pwms, npwm), PWMCHIP_ALIGN),
1548 sizeof_priv);
1549
1550 chip = kzalloc(alloc_size, GFP_KERNEL);
1551 if (!chip)
1552 return ERR_PTR(-ENOMEM);
1553
1554 chip->npwm = npwm;
1555 chip->uses_pwmchip_alloc = true;
1556 chip->operational = false;
1557
1558 pwmchip_dev = &chip->dev;
1559 device_initialize(pwmchip_dev);
1560 pwmchip_dev->class = &pwm_class;
1561 pwmchip_dev->parent = parent;
1562 pwmchip_dev->release = pwmchip_release;
1563
1564 pwmchip_set_drvdata(chip, pwmchip_priv(chip));
1565
1566 for (i = 0; i < chip->npwm; i++) {
1567 struct pwm_device *pwm = &chip->pwms[i];
1568 pwm->chip = chip;
1569 pwm->hwpwm = i;
1570 }
1571
1572 return chip;
1573}
1574EXPORT_SYMBOL_GPL(pwmchip_alloc);
1575
1576static void devm_pwmchip_put(void *data)
1577{
1578 struct pwm_chip *chip = data;
1579
1580 pwmchip_put(chip);
1581}
1582
1583struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv)
1584{
1585 struct pwm_chip *chip;
1586 int ret;
1587
1588 chip = pwmchip_alloc(parent, npwm, sizeof_priv);
1589 if (IS_ERR(chip))
1590 return chip;
1591
1592 ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip);
1593 if (ret)
1594 return ERR_PTR(ret);
1595
1596 return chip;
1597}
1598EXPORT_SYMBOL_GPL(devm_pwmchip_alloc);
1599
1600static void of_pwmchip_add(struct pwm_chip *chip)
1601{
1602 if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node)
1603 return;
1604
1605 if (!chip->of_xlate)
1606 chip->of_xlate = of_pwm_xlate_with_flags;
1607
1608 of_node_get(pwmchip_parent(chip)->of_node);
1609}
1610
1611static void of_pwmchip_remove(struct pwm_chip *chip)
1612{
1613 if (pwmchip_parent(chip))
1614 of_node_put(pwmchip_parent(chip)->of_node);
1615}
1616
1617static bool pwm_ops_check(const struct pwm_chip *chip)
1618{
1619 const struct pwm_ops *ops = chip->ops;
1620
1621 if (ops->write_waveform) {
1622 if (!ops->round_waveform_tohw ||
1623 !ops->round_waveform_fromhw ||
1624 !ops->write_waveform)
1625 return false;
1626
1627 if (WFHWSIZE < ops->sizeof_wfhw) {
1628 dev_warn(pwmchip_parent(chip), "WFHWSIZE < %zu\n", ops->sizeof_wfhw);
1629 return false;
1630 }
1631 } else {
1632 if (!ops->apply)
1633 return false;
1634
1635 if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state)
1636 dev_warn(pwmchip_parent(chip),
1637 "Please implement the .get_state() callback\n");
1638 }
1639
1640 return true;
1641}
1642
1643static struct device_link *pwm_device_link_add(struct device *dev,
1644 struct pwm_device *pwm)
1645{
1646 struct device_link *dl;
1647
1648 if (!dev) {
1649 /*
1650 * No device for the PWM consumer has been provided. It may
1651 * impact the PM sequence ordering: the PWM supplier may get
1652 * suspended before the consumer.
1653 */
1654 dev_warn(pwmchip_parent(pwm->chip),
1655 "No consumer device specified to create a link to\n");
1656 return NULL;
1657 }
1658
1659 dl = device_link_add(dev, pwmchip_parent(pwm->chip), DL_FLAG_AUTOREMOVE_CONSUMER);
1660 if (!dl) {
1661 dev_err(dev, "failed to create device link to %s\n",
1662 dev_name(pwmchip_parent(pwm->chip)));
1663 return ERR_PTR(-EINVAL);
1664 }
1665
1666 return dl;
1667}
1668
1669static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode)
1670{
1671 struct pwm_chip *chip;
1672 unsigned long id, tmp;
1673
1674 guard(mutex)(&pwm_lock);
1675
1676 idr_for_each_entry_ul(&pwm_chips, chip, tmp, id)
1677 if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode))
1678 return chip;
1679
1680 return ERR_PTR(-EPROBE_DEFER);
1681}
1682
1683/**
1684 * of_pwm_get() - request a PWM via the PWM framework
1685 * @dev: device for PWM consumer
1686 * @np: device node to get the PWM from
1687 * @con_id: consumer name
1688 *
1689 * Returns the PWM device parsed from the phandle and index specified in the
1690 * "pwms" property of a device tree node or a negative error-code on failure.
1691 * Values parsed from the device tree are stored in the returned PWM device
1692 * object.
1693 *
1694 * If con_id is NULL, the first PWM device listed in the "pwms" property will
1695 * be requested. Otherwise the "pwm-names" property is used to do a reverse
1696 * lookup of the PWM index. This also means that the "pwm-names" property
1697 * becomes mandatory for devices that look up the PWM device via the con_id
1698 * parameter.
1699 *
1700 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1701 * error code on failure.
1702 */
1703static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
1704 const char *con_id)
1705{
1706 struct pwm_device *pwm = NULL;
1707 struct of_phandle_args args;
1708 struct device_link *dl;
1709 struct pwm_chip *chip;
1710 int index = 0;
1711 int err;
1712
1713 if (con_id) {
1714 index = of_property_match_string(np, "pwm-names", con_id);
1715 if (index < 0)
1716 return ERR_PTR(index);
1717 }
1718
1719 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
1720 &args);
1721 if (err) {
1722 pr_err("%s(): can't parse \"pwms\" property\n", __func__);
1723 return ERR_PTR(err);
1724 }
1725
1726 chip = fwnode_to_pwmchip(of_fwnode_handle(args.np));
1727 if (IS_ERR(chip)) {
1728 if (PTR_ERR(chip) != -EPROBE_DEFER)
1729 pr_err("%s(): PWM chip not found\n", __func__);
1730
1731 pwm = ERR_CAST(chip);
1732 goto put;
1733 }
1734
1735 pwm = chip->of_xlate(chip, &args);
1736 if (IS_ERR(pwm))
1737 goto put;
1738
1739 dl = pwm_device_link_add(dev, pwm);
1740 if (IS_ERR(dl)) {
1741 /* of_xlate ended up calling pwm_request_from_chip() */
1742 pwm_put(pwm);
1743 pwm = ERR_CAST(dl);
1744 goto put;
1745 }
1746
1747 /*
1748 * If a consumer name was not given, try to look it up from the
1749 * "pwm-names" property if it exists. Otherwise use the name of
1750 * the user device node.
1751 */
1752 if (!con_id) {
1753 err = of_property_read_string_index(np, "pwm-names", index,
1754 &con_id);
1755 if (err < 0)
1756 con_id = np->name;
1757 }
1758
1759 pwm->label = con_id;
1760
1761put:
1762 of_node_put(args.np);
1763
1764 return pwm;
1765}
1766
1767/**
1768 * acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI
1769 * @fwnode: firmware node to get the "pwms" property from
1770 *
1771 * Returns the PWM device parsed from the fwnode and index specified in the
1772 * "pwms" property or a negative error-code on failure.
1773 * Values parsed from the device tree are stored in the returned PWM device
1774 * object.
1775 *
1776 * This is analogous to of_pwm_get() except con_id is not yet supported.
1777 * ACPI entries must look like
1778 * Package () {"pwms", Package ()
1779 * { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}}
1780 *
1781 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1782 * error code on failure.
1783 */
1784static struct pwm_device *acpi_pwm_get(const struct fwnode_handle *fwnode)
1785{
1786 struct pwm_device *pwm;
1787 struct fwnode_reference_args args;
1788 struct pwm_chip *chip;
1789 int ret;
1790
1791 memset(&args, 0, sizeof(args));
1792
1793 ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args);
1794 if (ret < 0)
1795 return ERR_PTR(ret);
1796
1797 if (args.nargs < 2)
1798 return ERR_PTR(-EPROTO);
1799
1800 chip = fwnode_to_pwmchip(args.fwnode);
1801 if (IS_ERR(chip))
1802 return ERR_CAST(chip);
1803
1804 pwm = pwm_request_from_chip(chip, args.args[0], NULL);
1805 if (IS_ERR(pwm))
1806 return pwm;
1807
1808 pwm->args.period = args.args[1];
1809 pwm->args.polarity = PWM_POLARITY_NORMAL;
1810
1811 if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED)
1812 pwm->args.polarity = PWM_POLARITY_INVERSED;
1813
1814 return pwm;
1815}
1816
1817static DEFINE_MUTEX(pwm_lookup_lock);
1818static LIST_HEAD(pwm_lookup_list);
1819
1820/**
1821 * pwm_get() - look up and request a PWM device
1822 * @dev: device for PWM consumer
1823 * @con_id: consumer name
1824 *
1825 * Lookup is first attempted using DT. If the device was not instantiated from
1826 * a device tree, a PWM chip and a relative index is looked up via a table
1827 * supplied by board setup code (see pwm_add_table()).
1828 *
1829 * Once a PWM chip has been found the specified PWM device will be requested
1830 * and is ready to be used.
1831 *
1832 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1833 * error code on failure.
1834 */
1835struct pwm_device *pwm_get(struct device *dev, const char *con_id)
1836{
1837 const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
1838 const char *dev_id = dev ? dev_name(dev) : NULL;
1839 struct pwm_device *pwm;
1840 struct pwm_chip *chip;
1841 struct device_link *dl;
1842 unsigned int best = 0;
1843 struct pwm_lookup *p, *chosen = NULL;
1844 unsigned int match;
1845 int err;
1846
1847 /* look up via DT first */
1848 if (is_of_node(fwnode))
1849 return of_pwm_get(dev, to_of_node(fwnode), con_id);
1850
1851 /* then lookup via ACPI */
1852 if (is_acpi_node(fwnode)) {
1853 pwm = acpi_pwm_get(fwnode);
1854 if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT)
1855 return pwm;
1856 }
1857
1858 /*
1859 * We look up the provider in the static table typically provided by
1860 * board setup code. We first try to lookup the consumer device by
1861 * name. If the consumer device was passed in as NULL or if no match
1862 * was found, we try to find the consumer by directly looking it up
1863 * by name.
1864 *
1865 * If a match is found, the provider PWM chip is looked up by name
1866 * and a PWM device is requested using the PWM device per-chip index.
1867 *
1868 * The lookup algorithm was shamelessly taken from the clock
1869 * framework:
1870 *
1871 * We do slightly fuzzy matching here:
1872 * An entry with a NULL ID is assumed to be a wildcard.
1873 * If an entry has a device ID, it must match
1874 * If an entry has a connection ID, it must match
1875 * Then we take the most specific entry - with the following order
1876 * of precedence: dev+con > dev only > con only.
1877 */
1878 scoped_guard(mutex, &pwm_lookup_lock)
1879 list_for_each_entry(p, &pwm_lookup_list, list) {
1880 match = 0;
1881
1882 if (p->dev_id) {
1883 if (!dev_id || strcmp(p->dev_id, dev_id))
1884 continue;
1885
1886 match += 2;
1887 }
1888
1889 if (p->con_id) {
1890 if (!con_id || strcmp(p->con_id, con_id))
1891 continue;
1892
1893 match += 1;
1894 }
1895
1896 if (match > best) {
1897 chosen = p;
1898
1899 if (match != 3)
1900 best = match;
1901 else
1902 break;
1903 }
1904 }
1905
1906 if (!chosen)
1907 return ERR_PTR(-ENODEV);
1908
1909 chip = pwmchip_find_by_name(chosen->provider);
1910
1911 /*
1912 * If the lookup entry specifies a module, load the module and retry
1913 * the PWM chip lookup. This can be used to work around driver load
1914 * ordering issues if driver's can't be made to properly support the
1915 * deferred probe mechanism.
1916 */
1917 if (!chip && chosen->module) {
1918 err = request_module(chosen->module);
1919 if (err == 0)
1920 chip = pwmchip_find_by_name(chosen->provider);
1921 }
1922
1923 if (!chip)
1924 return ERR_PTR(-EPROBE_DEFER);
1925
1926 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
1927 if (IS_ERR(pwm))
1928 return pwm;
1929
1930 dl = pwm_device_link_add(dev, pwm);
1931 if (IS_ERR(dl)) {
1932 pwm_put(pwm);
1933 return ERR_CAST(dl);
1934 }
1935
1936 pwm->args.period = chosen->period;
1937 pwm->args.polarity = chosen->polarity;
1938
1939 return pwm;
1940}
1941EXPORT_SYMBOL_GPL(pwm_get);
1942
1943/**
1944 * pwm_put() - release a PWM device
1945 * @pwm: PWM device
1946 */
1947void pwm_put(struct pwm_device *pwm)
1948{
1949 struct pwm_chip *chip;
1950
1951 if (!pwm)
1952 return;
1953
1954 chip = pwm->chip;
1955
1956 guard(mutex)(&pwm_lock);
1957
1958 /*
1959 * Trigger a warning if a consumer called pwm_put() twice.
1960 * If the chip isn't operational, PWMF_REQUESTED was already cleared in
1961 * pwmchip_remove(). So don't warn in this case.
1962 */
1963 if (chip->operational && !test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
1964 pr_warn("PWM device already freed\n");
1965 return;
1966 }
1967
1968 if (chip->operational && chip->ops->free)
1969 pwm->chip->ops->free(pwm->chip, pwm);
1970
1971 pwm->label = NULL;
1972
1973 put_device(&chip->dev);
1974
1975 module_put(chip->owner);
1976}
1977EXPORT_SYMBOL_GPL(pwm_put);
1978
1979static void devm_pwm_release(void *pwm)
1980{
1981 pwm_put(pwm);
1982}
1983
1984/**
1985 * devm_pwm_get() - resource managed pwm_get()
1986 * @dev: device for PWM consumer
1987 * @con_id: consumer name
1988 *
1989 * This function performs like pwm_get() but the acquired PWM device will
1990 * automatically be released on driver detach.
1991 *
1992 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
1993 * error code on failure.
1994 */
1995struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
1996{
1997 struct pwm_device *pwm;
1998 int ret;
1999
2000 pwm = pwm_get(dev, con_id);
2001 if (IS_ERR(pwm))
2002 return pwm;
2003
2004 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
2005 if (ret)
2006 return ERR_PTR(ret);
2007
2008 return pwm;
2009}
2010EXPORT_SYMBOL_GPL(devm_pwm_get);
2011
2012/**
2013 * devm_fwnode_pwm_get() - request a resource managed PWM from firmware node
2014 * @dev: device for PWM consumer
2015 * @fwnode: firmware node to get the PWM from
2016 * @con_id: consumer name
2017 *
2018 * Returns the PWM device parsed from the firmware node. See of_pwm_get() and
2019 * acpi_pwm_get() for a detailed description.
2020 *
2021 * Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded
2022 * error code on failure.
2023 */
2024struct pwm_device *devm_fwnode_pwm_get(struct device *dev,
2025 struct fwnode_handle *fwnode,
2026 const char *con_id)
2027{
2028 struct pwm_device *pwm = ERR_PTR(-ENODEV);
2029 int ret;
2030
2031 if (is_of_node(fwnode))
2032 pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
2033 else if (is_acpi_node(fwnode))
2034 pwm = acpi_pwm_get(fwnode);
2035 if (IS_ERR(pwm))
2036 return pwm;
2037
2038 ret = devm_add_action_or_reset(dev, devm_pwm_release, pwm);
2039 if (ret)
2040 return ERR_PTR(ret);
2041
2042 return pwm;
2043}
2044EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
2045
2046/**
2047 * __pwmchip_add() - register a new PWM chip
2048 * @chip: the PWM chip to add
2049 * @owner: reference to the module providing the chip.
2050 *
2051 * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the
2052 * pwmchip_add wrapper to do this right.
2053 *
2054 * Returns: 0 on success or a negative error code on failure.
2055 */
2056int __pwmchip_add(struct pwm_chip *chip, struct module *owner)
2057{
2058 int ret;
2059
2060 if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm)
2061 return -EINVAL;
2062
2063 /*
2064 * a struct pwm_chip must be allocated using (devm_)pwmchip_alloc,
2065 * otherwise the embedded struct device might disappear too early
2066 * resulting in memory corruption.
2067 * Catch drivers that were not converted appropriately.
2068 */
2069 if (!chip->uses_pwmchip_alloc)
2070 return -EINVAL;
2071
2072 if (!pwm_ops_check(chip))
2073 return -EINVAL;
2074
2075 chip->owner = owner;
2076
2077 if (chip->atomic)
2078 spin_lock_init(&chip->atomic_lock);
2079 else
2080 mutex_init(&chip->nonatomic_lock);
2081
2082 guard(mutex)(&pwm_lock);
2083
2084 ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL);
2085 if (ret < 0)
2086 return ret;
2087
2088 chip->id = ret;
2089
2090 dev_set_name(&chip->dev, "pwmchip%u", chip->id);
2091
2092 if (IS_ENABLED(CONFIG_OF))
2093 of_pwmchip_add(chip);
2094
2095 scoped_guard(pwmchip, chip)
2096 chip->operational = true;
2097
2098 ret = device_add(&chip->dev);
2099 if (ret)
2100 goto err_device_add;
2101
2102 return 0;
2103
2104err_device_add:
2105 scoped_guard(pwmchip, chip)
2106 chip->operational = false;
2107
2108 if (IS_ENABLED(CONFIG_OF))
2109 of_pwmchip_remove(chip);
2110
2111 idr_remove(&pwm_chips, chip->id);
2112
2113 return ret;
2114}
2115EXPORT_SYMBOL_GPL(__pwmchip_add);
2116
2117/**
2118 * pwmchip_remove() - remove a PWM chip
2119 * @chip: the PWM chip to remove
2120 *
2121 * Removes a PWM chip.
2122 */
2123void pwmchip_remove(struct pwm_chip *chip)
2124{
2125 pwmchip_sysfs_unexport(chip);
2126
2127 scoped_guard(mutex, &pwm_lock) {
2128 unsigned int i;
2129
2130 scoped_guard(pwmchip, chip)
2131 chip->operational = false;
2132
2133 for (i = 0; i < chip->npwm; ++i) {
2134 struct pwm_device *pwm = &chip->pwms[i];
2135
2136 if (test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
2137 dev_warn(&chip->dev, "Freeing requested PWM #%u\n", i);
2138 if (pwm->chip->ops->free)
2139 pwm->chip->ops->free(pwm->chip, pwm);
2140 }
2141 }
2142
2143 if (IS_ENABLED(CONFIG_OF))
2144 of_pwmchip_remove(chip);
2145
2146 idr_remove(&pwm_chips, chip->id);
2147 }
2148
2149 device_del(&chip->dev);
2150}
2151EXPORT_SYMBOL_GPL(pwmchip_remove);
2152
2153static void devm_pwmchip_remove(void *data)
2154{
2155 struct pwm_chip *chip = data;
2156
2157 pwmchip_remove(chip);
2158}
2159
2160int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner)
2161{
2162 int ret;
2163
2164 ret = __pwmchip_add(chip, owner);
2165 if (ret)
2166 return ret;
2167
2168 return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip);
2169}
2170EXPORT_SYMBOL_GPL(__devm_pwmchip_add);
2171
2172/**
2173 * pwm_add_table() - register PWM device consumers
2174 * @table: array of consumers to register
2175 * @num: number of consumers in table
2176 */
2177void pwm_add_table(struct pwm_lookup *table, size_t num)
2178{
2179 guard(mutex)(&pwm_lookup_lock);
2180
2181 while (num--) {
2182 list_add_tail(&table->list, &pwm_lookup_list);
2183 table++;
2184 }
2185}
2186
2187/**
2188 * pwm_remove_table() - unregister PWM device consumers
2189 * @table: array of consumers to unregister
2190 * @num: number of consumers in table
2191 */
2192void pwm_remove_table(struct pwm_lookup *table, size_t num)
2193{
2194 guard(mutex)(&pwm_lookup_lock);
2195
2196 while (num--) {
2197 list_del(&table->list);
2198 table++;
2199 }
2200}
2201
2202static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
2203{
2204 unsigned int i;
2205
2206 for (i = 0; i < chip->npwm; i++) {
2207 struct pwm_device *pwm = &chip->pwms[i];
2208 struct pwm_state state;
2209
2210 pwm_get_state(pwm, &state);
2211
2212 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
2213
2214 if (test_bit(PWMF_REQUESTED, &pwm->flags))
2215 seq_puts(s, " requested");
2216
2217 if (state.enabled)
2218 seq_puts(s, " enabled");
2219
2220 seq_printf(s, " period: %llu ns", state.period);
2221 seq_printf(s, " duty: %llu ns", state.duty_cycle);
2222 seq_printf(s, " polarity: %s",
2223 state.polarity ? "inverse" : "normal");
2224
2225 if (state.usage_power)
2226 seq_puts(s, " usage_power");
2227
2228 seq_puts(s, "\n");
2229 }
2230}
2231
2232static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
2233{
2234 unsigned long id = *pos;
2235 void *ret;
2236
2237 mutex_lock(&pwm_lock);
2238 s->private = "";
2239
2240 ret = idr_get_next_ul(&pwm_chips, &id);
2241 *pos = id;
2242 return ret;
2243}
2244
2245static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
2246{
2247 unsigned long id = *pos + 1;
2248 void *ret;
2249
2250 s->private = "\n";
2251
2252 ret = idr_get_next_ul(&pwm_chips, &id);
2253 *pos = id;
2254 return ret;
2255}
2256
2257static void pwm_seq_stop(struct seq_file *s, void *v)
2258{
2259 mutex_unlock(&pwm_lock);
2260}
2261
2262static int pwm_seq_show(struct seq_file *s, void *v)
2263{
2264 struct pwm_chip *chip = v;
2265
2266 seq_printf(s, "%s%d: %s/%s, %d PWM device%s\n",
2267 (char *)s->private, chip->id,
2268 pwmchip_parent(chip)->bus ? pwmchip_parent(chip)->bus->name : "no-bus",
2269 dev_name(pwmchip_parent(chip)), chip->npwm,
2270 (chip->npwm != 1) ? "s" : "");
2271
2272 pwm_dbg_show(chip, s);
2273
2274 return 0;
2275}
2276
2277static const struct seq_operations pwm_debugfs_sops = {
2278 .start = pwm_seq_start,
2279 .next = pwm_seq_next,
2280 .stop = pwm_seq_stop,
2281 .show = pwm_seq_show,
2282};
2283
2284DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
2285
2286static int __init pwm_init(void)
2287{
2288 int ret;
2289
2290 ret = class_register(&pwm_class);
2291 if (ret) {
2292 pr_err("Failed to initialize PWM class (%pe)\n", ERR_PTR(ret));
2293 return ret;
2294 }
2295
2296 if (IS_ENABLED(CONFIG_DEBUG_FS))
2297 debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
2298
2299 return 0;
2300}
2301subsys_initcall(pwm_init);