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22#include <linux/module.h>
23#include <linux/pwm.h>
24#include <linux/radix-tree.h>
25#include <linux/list.h>
26#include <linux/mutex.h>
27#include <linux/err.h>
28#include <linux/slab.h>
29#include <linux/device.h>
30#include <linux/debugfs.h>
31#include <linux/seq_file.h>
32
33#include <dt-bindings/pwm/pwm.h>
34
35#define MAX_PWMS 1024
36
37static DEFINE_MUTEX(pwm_lookup_lock);
38static LIST_HEAD(pwm_lookup_list);
39static DEFINE_MUTEX(pwm_lock);
40static LIST_HEAD(pwm_chips);
41static DECLARE_BITMAP(allocated_pwms, MAX_PWMS);
42static RADIX_TREE(pwm_tree, GFP_KERNEL);
43
44static struct pwm_device *pwm_to_device(unsigned int pwm)
45{
46 return radix_tree_lookup(&pwm_tree, pwm);
47}
48
49static int alloc_pwms(int pwm, unsigned int count)
50{
51 unsigned int from = 0;
52 unsigned int start;
53
54 if (pwm >= MAX_PWMS)
55 return -EINVAL;
56
57 if (pwm >= 0)
58 from = pwm;
59
60 start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from,
61 count, 0);
62
63 if (pwm >= 0 && start != pwm)
64 return -EEXIST;
65
66 if (start + count > MAX_PWMS)
67 return -ENOSPC;
68
69 return start;
70}
71
72static void free_pwms(struct pwm_chip *chip)
73{
74 unsigned int i;
75
76 for (i = 0; i < chip->npwm; i++) {
77 struct pwm_device *pwm = &chip->pwms[i];
78 radix_tree_delete(&pwm_tree, pwm->pwm);
79 }
80
81 bitmap_clear(allocated_pwms, chip->base, chip->npwm);
82
83 kfree(chip->pwms);
84 chip->pwms = NULL;
85}
86
87static struct pwm_chip *pwmchip_find_by_name(const char *name)
88{
89 struct pwm_chip *chip;
90
91 if (!name)
92 return NULL;
93
94 mutex_lock(&pwm_lock);
95
96 list_for_each_entry(chip, &pwm_chips, list) {
97 const char *chip_name = dev_name(chip->dev);
98
99 if (chip_name && strcmp(chip_name, name) == 0) {
100 mutex_unlock(&pwm_lock);
101 return chip;
102 }
103 }
104
105 mutex_unlock(&pwm_lock);
106
107 return NULL;
108}
109
110static int pwm_device_request(struct pwm_device *pwm, const char *label)
111{
112 int err;
113
114 if (test_bit(PWMF_REQUESTED, &pwm->flags))
115 return -EBUSY;
116
117 if (!try_module_get(pwm->chip->ops->owner))
118 return -ENODEV;
119
120 if (pwm->chip->ops->request) {
121 err = pwm->chip->ops->request(pwm->chip, pwm);
122 if (err) {
123 module_put(pwm->chip->ops->owner);
124 return err;
125 }
126 }
127
128 set_bit(PWMF_REQUESTED, &pwm->flags);
129 pwm->label = label;
130
131 return 0;
132}
133
134struct pwm_device *
135of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
136{
137 struct pwm_device *pwm;
138
139 if (pc->of_pwm_n_cells < 3)
140 return ERR_PTR(-EINVAL);
141
142 if (args->args[0] >= pc->npwm)
143 return ERR_PTR(-EINVAL);
144
145 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
146 if (IS_ERR(pwm))
147 return pwm;
148
149 pwm_set_period(pwm, args->args[1]);
150
151 if (args->args[2] & PWM_POLARITY_INVERTED)
152 pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
153 else
154 pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
155
156 return pwm;
157}
158EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);
159
160static struct pwm_device *
161of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
162{
163 struct pwm_device *pwm;
164
165 if (pc->of_pwm_n_cells < 2)
166 return ERR_PTR(-EINVAL);
167
168 if (args->args[0] >= pc->npwm)
169 return ERR_PTR(-EINVAL);
170
171 pwm = pwm_request_from_chip(pc, args->args[0], NULL);
172 if (IS_ERR(pwm))
173 return pwm;
174
175 pwm_set_period(pwm, args->args[1]);
176
177 return pwm;
178}
179
180static void of_pwmchip_add(struct pwm_chip *chip)
181{
182 if (!chip->dev || !chip->dev->of_node)
183 return;
184
185 if (!chip->of_xlate) {
186 chip->of_xlate = of_pwm_simple_xlate;
187 chip->of_pwm_n_cells = 2;
188 }
189
190 of_node_get(chip->dev->of_node);
191}
192
193static void of_pwmchip_remove(struct pwm_chip *chip)
194{
195 if (chip->dev)
196 of_node_put(chip->dev->of_node);
197}
198
199
200
201
202
203
204
205
206int pwm_set_chip_data(struct pwm_device *pwm, void *data)
207{
208 if (!pwm)
209 return -EINVAL;
210
211 pwm->chip_data = data;
212
213 return 0;
214}
215EXPORT_SYMBOL_GPL(pwm_set_chip_data);
216
217
218
219
220
221
222
223void *pwm_get_chip_data(struct pwm_device *pwm)
224{
225 return pwm ? pwm->chip_data : NULL;
226}
227EXPORT_SYMBOL_GPL(pwm_get_chip_data);
228
229
230
231
232
233
234
235
236
237
238
239
240int pwmchip_add_with_polarity(struct pwm_chip *chip,
241 enum pwm_polarity polarity)
242{
243 struct pwm_device *pwm;
244 unsigned int i;
245 int ret;
246
247 if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
248 !chip->ops->enable || !chip->ops->disable || !chip->npwm)
249 return -EINVAL;
250
251 mutex_lock(&pwm_lock);
252
253 ret = alloc_pwms(chip->base, chip->npwm);
254 if (ret < 0)
255 goto out;
256
257 chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
258 if (!chip->pwms) {
259 ret = -ENOMEM;
260 goto out;
261 }
262
263 chip->base = ret;
264
265 for (i = 0; i < chip->npwm; i++) {
266 pwm = &chip->pwms[i];
267
268 pwm->chip = chip;
269 pwm->pwm = chip->base + i;
270 pwm->hwpwm = i;
271 pwm->polarity = polarity;
272
273 radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
274 }
275
276 bitmap_set(allocated_pwms, chip->base, chip->npwm);
277
278 INIT_LIST_HEAD(&chip->list);
279 list_add(&chip->list, &pwm_chips);
280
281 ret = 0;
282
283 if (IS_ENABLED(CONFIG_OF))
284 of_pwmchip_add(chip);
285
286 pwmchip_sysfs_export(chip);
287
288out:
289 mutex_unlock(&pwm_lock);
290 return ret;
291}
292EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity);
293
294
295
296
297
298
299
300
301
302
303int pwmchip_add(struct pwm_chip *chip)
304{
305 return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL);
306}
307EXPORT_SYMBOL_GPL(pwmchip_add);
308
309
310
311
312
313
314
315
316
317
318int pwmchip_remove(struct pwm_chip *chip)
319{
320 unsigned int i;
321 int ret = 0;
322
323 mutex_lock(&pwm_lock);
324
325 for (i = 0; i < chip->npwm; i++) {
326 struct pwm_device *pwm = &chip->pwms[i];
327
328 if (test_bit(PWMF_REQUESTED, &pwm->flags)) {
329 ret = -EBUSY;
330 goto out;
331 }
332 }
333
334 list_del_init(&chip->list);
335
336 if (IS_ENABLED(CONFIG_OF))
337 of_pwmchip_remove(chip);
338
339 free_pwms(chip);
340
341 pwmchip_sysfs_unexport(chip);
342
343out:
344 mutex_unlock(&pwm_lock);
345 return ret;
346}
347EXPORT_SYMBOL_GPL(pwmchip_remove);
348
349
350
351
352
353
354
355
356
357
358
359struct pwm_device *pwm_request(int pwm, const char *label)
360{
361 struct pwm_device *dev;
362 int err;
363
364 if (pwm < 0 || pwm >= MAX_PWMS)
365 return ERR_PTR(-EINVAL);
366
367 mutex_lock(&pwm_lock);
368
369 dev = pwm_to_device(pwm);
370 if (!dev) {
371 dev = ERR_PTR(-EPROBE_DEFER);
372 goto out;
373 }
374
375 err = pwm_device_request(dev, label);
376 if (err < 0)
377 dev = ERR_PTR(err);
378
379out:
380 mutex_unlock(&pwm_lock);
381
382 return dev;
383}
384EXPORT_SYMBOL_GPL(pwm_request);
385
386
387
388
389
390
391
392
393
394
395
396struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,
397 unsigned int index,
398 const char *label)
399{
400 struct pwm_device *pwm;
401 int err;
402
403 if (!chip || index >= chip->npwm)
404 return ERR_PTR(-EINVAL);
405
406 mutex_lock(&pwm_lock);
407 pwm = &chip->pwms[index];
408
409 err = pwm_device_request(pwm, label);
410 if (err < 0)
411 pwm = ERR_PTR(err);
412
413 mutex_unlock(&pwm_lock);
414 return pwm;
415}
416EXPORT_SYMBOL_GPL(pwm_request_from_chip);
417
418
419
420
421
422
423
424void pwm_free(struct pwm_device *pwm)
425{
426 pwm_put(pwm);
427}
428EXPORT_SYMBOL_GPL(pwm_free);
429
430
431
432
433
434
435
436
437
438int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
439{
440 int err;
441
442 if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
443 return -EINVAL;
444
445 err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
446 if (err)
447 return err;
448
449 pwm->duty_cycle = duty_ns;
450 pwm->period = period_ns;
451
452 return 0;
453}
454EXPORT_SYMBOL_GPL(pwm_config);
455
456
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458
459
460
461
462
463
464
465
466int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
467{
468 int err;
469
470 if (!pwm || !pwm->chip->ops)
471 return -EINVAL;
472
473 if (!pwm->chip->ops->set_polarity)
474 return -ENOSYS;
475
476 if (pwm_is_enabled(pwm))
477 return -EBUSY;
478
479 err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
480 if (err)
481 return err;
482
483 pwm->polarity = polarity;
484
485 return 0;
486}
487EXPORT_SYMBOL_GPL(pwm_set_polarity);
488
489
490
491
492
493
494
495int pwm_enable(struct pwm_device *pwm)
496{
497 if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
498 return pwm->chip->ops->enable(pwm->chip, pwm);
499
500 return pwm ? 0 : -EINVAL;
501}
502EXPORT_SYMBOL_GPL(pwm_enable);
503
504
505
506
507
508void pwm_disable(struct pwm_device *pwm)
509{
510 if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
511 pwm->chip->ops->disable(pwm->chip, pwm);
512}
513EXPORT_SYMBOL_GPL(pwm_disable);
514
515static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
516{
517 struct pwm_chip *chip;
518
519 mutex_lock(&pwm_lock);
520
521 list_for_each_entry(chip, &pwm_chips, list)
522 if (chip->dev && chip->dev->of_node == np) {
523 mutex_unlock(&pwm_lock);
524 return chip;
525 }
526
527 mutex_unlock(&pwm_lock);
528
529 return ERR_PTR(-EPROBE_DEFER);
530}
531
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541
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549
550
551struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
552{
553 struct pwm_device *pwm = NULL;
554 struct of_phandle_args args;
555 struct pwm_chip *pc;
556 int index = 0;
557 int err;
558
559 if (con_id) {
560 index = of_property_match_string(np, "pwm-names", con_id);
561 if (index < 0)
562 return ERR_PTR(index);
563 }
564
565 err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
566 &args);
567 if (err) {
568 pr_debug("%s(): can't parse \"pwms\" property\n", __func__);
569 return ERR_PTR(err);
570 }
571
572 pc = of_node_to_pwmchip(args.np);
573 if (IS_ERR(pc)) {
574 pr_debug("%s(): PWM chip not found\n", __func__);
575 pwm = ERR_CAST(pc);
576 goto put;
577 }
578
579 if (args.args_count != pc->of_pwm_n_cells) {
580 pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name,
581 args.np->full_name);
582 pwm = ERR_PTR(-EINVAL);
583 goto put;
584 }
585
586 pwm = pc->of_xlate(pc, &args);
587 if (IS_ERR(pwm))
588 goto put;
589
590
591
592
593
594
595 if (!con_id) {
596 err = of_property_read_string_index(np, "pwm-names", index,
597 &con_id);
598 if (err < 0)
599 con_id = np->name;
600 }
601
602 pwm->label = con_id;
603
604put:
605 of_node_put(args.np);
606
607 return pwm;
608}
609EXPORT_SYMBOL_GPL(of_pwm_get);
610
611
612
613
614
615
616void pwm_add_table(struct pwm_lookup *table, size_t num)
617{
618 mutex_lock(&pwm_lookup_lock);
619
620 while (num--) {
621 list_add_tail(&table->list, &pwm_lookup_list);
622 table++;
623 }
624
625 mutex_unlock(&pwm_lookup_lock);
626}
627
628
629
630
631
632
633void pwm_remove_table(struct pwm_lookup *table, size_t num)
634{
635 mutex_lock(&pwm_lookup_lock);
636
637 while (num--) {
638 list_del(&table->list);
639 table++;
640 }
641
642 mutex_unlock(&pwm_lookup_lock);
643}
644
645
646
647
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649
650
651
652
653
654
655
656
657
658
659
660struct pwm_device *pwm_get(struct device *dev, const char *con_id)
661{
662 struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER);
663 const char *dev_id = dev ? dev_name(dev) : NULL;
664 struct pwm_chip *chip = NULL;
665 unsigned int best = 0;
666 struct pwm_lookup *p, *chosen = NULL;
667 unsigned int match;
668
669
670 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
671 return of_pwm_get(dev->of_node, con_id);
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693 mutex_lock(&pwm_lookup_lock);
694
695 list_for_each_entry(p, &pwm_lookup_list, list) {
696 match = 0;
697
698 if (p->dev_id) {
699 if (!dev_id || strcmp(p->dev_id, dev_id))
700 continue;
701
702 match += 2;
703 }
704
705 if (p->con_id) {
706 if (!con_id || strcmp(p->con_id, con_id))
707 continue;
708
709 match += 1;
710 }
711
712 if (match > best) {
713 chosen = p;
714
715 if (match != 3)
716 best = match;
717 else
718 break;
719 }
720 }
721
722 if (!chosen)
723 goto out;
724
725 chip = pwmchip_find_by_name(chosen->provider);
726 if (!chip)
727 goto out;
728
729 pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
730 if (IS_ERR(pwm))
731 goto out;
732
733 pwm_set_period(pwm, chosen->period);
734 pwm_set_polarity(pwm, chosen->polarity);
735
736out:
737 mutex_unlock(&pwm_lookup_lock);
738 return pwm;
739}
740EXPORT_SYMBOL_GPL(pwm_get);
741
742
743
744
745
746void pwm_put(struct pwm_device *pwm)
747{
748 if (!pwm)
749 return;
750
751 mutex_lock(&pwm_lock);
752
753 if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) {
754 pr_warn("PWM device already freed\n");
755 goto out;
756 }
757
758 if (pwm->chip->ops->free)
759 pwm->chip->ops->free(pwm->chip, pwm);
760
761 pwm->label = NULL;
762
763 module_put(pwm->chip->ops->owner);
764out:
765 mutex_unlock(&pwm_lock);
766}
767EXPORT_SYMBOL_GPL(pwm_put);
768
769static void devm_pwm_release(struct device *dev, void *res)
770{
771 pwm_put(*(struct pwm_device **)res);
772}
773
774
775
776
777
778
779
780
781
782
783
784
785struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
786{
787 struct pwm_device **ptr, *pwm;
788
789 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
790 if (!ptr)
791 return ERR_PTR(-ENOMEM);
792
793 pwm = pwm_get(dev, con_id);
794 if (!IS_ERR(pwm)) {
795 *ptr = pwm;
796 devres_add(dev, ptr);
797 } else {
798 devres_free(ptr);
799 }
800
801 return pwm;
802}
803EXPORT_SYMBOL_GPL(devm_pwm_get);
804
805
806
807
808
809
810
811
812
813
814
815
816
817struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
818 const char *con_id)
819{
820 struct pwm_device **ptr, *pwm;
821
822 ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
823 if (!ptr)
824 return ERR_PTR(-ENOMEM);
825
826 pwm = of_pwm_get(np, con_id);
827 if (!IS_ERR(pwm)) {
828 *ptr = pwm;
829 devres_add(dev, ptr);
830 } else {
831 devres_free(ptr);
832 }
833
834 return pwm;
835}
836EXPORT_SYMBOL_GPL(devm_of_pwm_get);
837
838static int devm_pwm_match(struct device *dev, void *res, void *data)
839{
840 struct pwm_device **p = res;
841
842 if (WARN_ON(!p || !*p))
843 return 0;
844
845 return *p == data;
846}
847
848
849
850
851
852
853
854
855
856
857void devm_pwm_put(struct device *dev, struct pwm_device *pwm)
858{
859 WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm));
860}
861EXPORT_SYMBOL_GPL(devm_pwm_put);
862
863
864
865
866
867
868
869bool pwm_can_sleep(struct pwm_device *pwm)
870{
871 return pwm->chip->can_sleep;
872}
873EXPORT_SYMBOL_GPL(pwm_can_sleep);
874
875#ifdef CONFIG_DEBUG_FS
876static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
877{
878 unsigned int i;
879
880 for (i = 0; i < chip->npwm; i++) {
881 struct pwm_device *pwm = &chip->pwms[i];
882
883 seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);
884
885 if (test_bit(PWMF_REQUESTED, &pwm->flags))
886 seq_puts(s, " requested");
887
888 if (pwm_is_enabled(pwm))
889 seq_puts(s, " enabled");
890
891 seq_puts(s, "\n");
892 }
893}
894
895static void *pwm_seq_start(struct seq_file *s, loff_t *pos)
896{
897 mutex_lock(&pwm_lock);
898 s->private = "";
899
900 return seq_list_start(&pwm_chips, *pos);
901}
902
903static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos)
904{
905 s->private = "\n";
906
907 return seq_list_next(v, &pwm_chips, pos);
908}
909
910static void pwm_seq_stop(struct seq_file *s, void *v)
911{
912 mutex_unlock(&pwm_lock);
913}
914
915static int pwm_seq_show(struct seq_file *s, void *v)
916{
917 struct pwm_chip *chip = list_entry(v, struct pwm_chip, list);
918
919 seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private,
920 chip->dev->bus ? chip->dev->bus->name : "no-bus",
921 dev_name(chip->dev), chip->npwm,
922 (chip->npwm != 1) ? "s" : "");
923
924 if (chip->ops->dbg_show)
925 chip->ops->dbg_show(chip, s);
926 else
927 pwm_dbg_show(chip, s);
928
929 return 0;
930}
931
932static const struct seq_operations pwm_seq_ops = {
933 .start = pwm_seq_start,
934 .next = pwm_seq_next,
935 .stop = pwm_seq_stop,
936 .show = pwm_seq_show,
937};
938
939static int pwm_seq_open(struct inode *inode, struct file *file)
940{
941 return seq_open(file, &pwm_seq_ops);
942}
943
944static const struct file_operations pwm_debugfs_ops = {
945 .owner = THIS_MODULE,
946 .open = pwm_seq_open,
947 .read = seq_read,
948 .llseek = seq_lseek,
949 .release = seq_release,
950};
951
952static int __init pwm_debugfs_init(void)
953{
954 debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL,
955 &pwm_debugfs_ops);
956
957 return 0;
958}
959subsys_initcall(pwm_debugfs_init);
960#endif
961