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13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/errno.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/stat.h>
21#include <linux/pm_opp.h>
22#include <linux/devfreq.h>
23#include <linux/workqueue.h>
24#include <linux/platform_device.h>
25#include <linux/list.h>
26#include <linux/printk.h>
27#include <linux/hrtimer.h>
28#include "governor.h"
29
30static struct class *devfreq_class;
31
32
33
34
35
36
37static struct workqueue_struct *devfreq_wq;
38
39
40static LIST_HEAD(devfreq_governor_list);
41
42static LIST_HEAD(devfreq_list);
43static DEFINE_MUTEX(devfreq_list_lock);
44
45
46
47
48
49
50
51
52static struct devfreq *find_device_devfreq(struct device *dev)
53{
54 struct devfreq *tmp_devfreq;
55
56 if (unlikely(IS_ERR_OR_NULL(dev))) {
57 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
58 return ERR_PTR(-EINVAL);
59 }
60 WARN(!mutex_is_locked(&devfreq_list_lock),
61 "devfreq_list_lock must be locked.");
62
63 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
64 if (tmp_devfreq->dev.parent == dev)
65 return tmp_devfreq;
66 }
67
68 return ERR_PTR(-ENODEV);
69}
70
71
72
73
74
75
76static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
77{
78 int lev;
79
80 for (lev = 0; lev < devfreq->profile->max_state; lev++)
81 if (freq == devfreq->profile->freq_table[lev])
82 return lev;
83
84 return -EINVAL;
85}
86
87
88
89
90
91
92static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
93{
94 int lev, prev_lev, ret = 0;
95 unsigned long cur_time;
96
97 cur_time = jiffies;
98
99 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
100 if (prev_lev < 0) {
101 ret = prev_lev;
102 goto out;
103 }
104
105 devfreq->time_in_state[prev_lev] +=
106 cur_time - devfreq->last_stat_updated;
107
108 lev = devfreq_get_freq_level(devfreq, freq);
109 if (lev < 0) {
110 ret = lev;
111 goto out;
112 }
113
114 if (lev != prev_lev) {
115 devfreq->trans_table[(prev_lev *
116 devfreq->profile->max_state) + lev]++;
117 devfreq->total_trans++;
118 }
119
120out:
121 devfreq->last_stat_updated = cur_time;
122 return ret;
123}
124
125
126
127
128
129
130
131
132static struct devfreq_governor *find_devfreq_governor(const char *name)
133{
134 struct devfreq_governor *tmp_governor;
135
136 if (unlikely(IS_ERR_OR_NULL(name))) {
137 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
138 return ERR_PTR(-EINVAL);
139 }
140 WARN(!mutex_is_locked(&devfreq_list_lock),
141 "devfreq_list_lock must be locked.");
142
143 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
144 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
145 return tmp_governor;
146 }
147
148 return ERR_PTR(-ENODEV);
149}
150
151
152
153
154
155
156
157
158
159
160int update_devfreq(struct devfreq *devfreq)
161{
162 unsigned long freq;
163 int err = 0;
164 u32 flags = 0;
165
166 if (!mutex_is_locked(&devfreq->lock)) {
167 WARN(true, "devfreq->lock must be locked by the caller.\n");
168 return -EINVAL;
169 }
170
171 if (!devfreq->governor)
172 return -EINVAL;
173
174
175 err = devfreq->governor->get_target_freq(devfreq, &freq);
176 if (err)
177 return err;
178
179
180
181
182
183
184
185
186
187 if (devfreq->min_freq && freq < devfreq->min_freq) {
188 freq = devfreq->min_freq;
189 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND;
190 }
191 if (devfreq->max_freq && freq > devfreq->max_freq) {
192 freq = devfreq->max_freq;
193 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND;
194 }
195
196 err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
197 if (err)
198 return err;
199
200 if (devfreq->profile->freq_table)
201 if (devfreq_update_status(devfreq, freq))
202 dev_err(&devfreq->dev,
203 "Couldn't update frequency transition information.\n");
204
205 devfreq->previous_freq = freq;
206 return err;
207}
208EXPORT_SYMBOL(update_devfreq);
209
210
211
212
213
214
215static void devfreq_monitor(struct work_struct *work)
216{
217 int err;
218 struct devfreq *devfreq = container_of(work,
219 struct devfreq, work.work);
220
221 mutex_lock(&devfreq->lock);
222 err = update_devfreq(devfreq);
223 if (err)
224 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
225
226 queue_delayed_work(devfreq_wq, &devfreq->work,
227 msecs_to_jiffies(devfreq->profile->polling_ms));
228 mutex_unlock(&devfreq->lock);
229}
230
231
232
233
234
235
236
237
238
239
240void devfreq_monitor_start(struct devfreq *devfreq)
241{
242 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
243 if (devfreq->profile->polling_ms)
244 queue_delayed_work(devfreq_wq, &devfreq->work,
245 msecs_to_jiffies(devfreq->profile->polling_ms));
246}
247EXPORT_SYMBOL(devfreq_monitor_start);
248
249
250
251
252
253
254
255
256
257void devfreq_monitor_stop(struct devfreq *devfreq)
258{
259 cancel_delayed_work_sync(&devfreq->work);
260}
261EXPORT_SYMBOL(devfreq_monitor_stop);
262
263
264
265
266
267
268
269
270
271
272
273
274
275void devfreq_monitor_suspend(struct devfreq *devfreq)
276{
277 mutex_lock(&devfreq->lock);
278 if (devfreq->stop_polling) {
279 mutex_unlock(&devfreq->lock);
280 return;
281 }
282
283 devfreq_update_status(devfreq, devfreq->previous_freq);
284 devfreq->stop_polling = true;
285 mutex_unlock(&devfreq->lock);
286 cancel_delayed_work_sync(&devfreq->work);
287}
288EXPORT_SYMBOL(devfreq_monitor_suspend);
289
290
291
292
293
294
295
296
297
298void devfreq_monitor_resume(struct devfreq *devfreq)
299{
300 unsigned long freq;
301
302 mutex_lock(&devfreq->lock);
303 if (!devfreq->stop_polling)
304 goto out;
305
306 if (!delayed_work_pending(&devfreq->work) &&
307 devfreq->profile->polling_ms)
308 queue_delayed_work(devfreq_wq, &devfreq->work,
309 msecs_to_jiffies(devfreq->profile->polling_ms));
310
311 devfreq->last_stat_updated = jiffies;
312 devfreq->stop_polling = false;
313
314 if (devfreq->profile->get_cur_freq &&
315 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
316 devfreq->previous_freq = freq;
317
318out:
319 mutex_unlock(&devfreq->lock);
320}
321EXPORT_SYMBOL(devfreq_monitor_resume);
322
323
324
325
326
327
328
329
330
331void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay)
332{
333 unsigned int cur_delay = devfreq->profile->polling_ms;
334 unsigned int new_delay = *delay;
335
336 mutex_lock(&devfreq->lock);
337 devfreq->profile->polling_ms = new_delay;
338
339 if (devfreq->stop_polling)
340 goto out;
341
342
343 if (!new_delay) {
344 mutex_unlock(&devfreq->lock);
345 cancel_delayed_work_sync(&devfreq->work);
346 return;
347 }
348
349
350 if (!cur_delay) {
351 queue_delayed_work(devfreq_wq, &devfreq->work,
352 msecs_to_jiffies(devfreq->profile->polling_ms));
353 goto out;
354 }
355
356
357 if (cur_delay > new_delay) {
358 mutex_unlock(&devfreq->lock);
359 cancel_delayed_work_sync(&devfreq->work);
360 mutex_lock(&devfreq->lock);
361 if (!devfreq->stop_polling)
362 queue_delayed_work(devfreq_wq, &devfreq->work,
363 msecs_to_jiffies(devfreq->profile->polling_ms));
364 }
365out:
366 mutex_unlock(&devfreq->lock);
367}
368EXPORT_SYMBOL(devfreq_interval_update);
369
370
371
372
373
374
375
376
377
378
379static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
380 void *devp)
381{
382 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
383 int ret;
384
385 mutex_lock(&devfreq->lock);
386 ret = update_devfreq(devfreq);
387 mutex_unlock(&devfreq->lock);
388
389 return ret;
390}
391
392
393
394
395
396
397static void _remove_devfreq(struct devfreq *devfreq)
398{
399 mutex_lock(&devfreq_list_lock);
400 if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
401 mutex_unlock(&devfreq_list_lock);
402 dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
403 return;
404 }
405 list_del(&devfreq->node);
406 mutex_unlock(&devfreq_list_lock);
407
408 if (devfreq->governor)
409 devfreq->governor->event_handler(devfreq,
410 DEVFREQ_GOV_STOP, NULL);
411
412 if (devfreq->profile->exit)
413 devfreq->profile->exit(devfreq->dev.parent);
414
415 mutex_destroy(&devfreq->lock);
416 kfree(devfreq);
417}
418
419
420
421
422
423
424
425static void devfreq_dev_release(struct device *dev)
426{
427 struct devfreq *devfreq = to_devfreq(dev);
428
429 _remove_devfreq(devfreq);
430}
431
432
433
434
435
436
437
438
439
440struct devfreq *devfreq_add_device(struct device *dev,
441 struct devfreq_dev_profile *profile,
442 const char *governor_name,
443 void *data)
444{
445 struct devfreq *devfreq;
446 struct devfreq_governor *governor;
447 int err = 0;
448
449 if (!dev || !profile || !governor_name) {
450 dev_err(dev, "%s: Invalid parameters.\n", __func__);
451 return ERR_PTR(-EINVAL);
452 }
453
454 mutex_lock(&devfreq_list_lock);
455 devfreq = find_device_devfreq(dev);
456 mutex_unlock(&devfreq_list_lock);
457 if (!IS_ERR(devfreq)) {
458 dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
459 err = -EINVAL;
460 goto err_out;
461 }
462
463 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
464 if (!devfreq) {
465 dev_err(dev, "%s: Unable to create devfreq for the device\n",
466 __func__);
467 err = -ENOMEM;
468 goto err_out;
469 }
470
471 mutex_init(&devfreq->lock);
472 mutex_lock(&devfreq->lock);
473 devfreq->dev.parent = dev;
474 devfreq->dev.class = devfreq_class;
475 devfreq->dev.release = devfreq_dev_release;
476 devfreq->profile = profile;
477 strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
478 devfreq->previous_freq = profile->initial_freq;
479 devfreq->data = data;
480 devfreq->nb.notifier_call = devfreq_notifier_call;
481
482 devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) *
483 devfreq->profile->max_state *
484 devfreq->profile->max_state,
485 GFP_KERNEL);
486 devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) *
487 devfreq->profile->max_state,
488 GFP_KERNEL);
489 devfreq->last_stat_updated = jiffies;
490
491 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
492 err = device_register(&devfreq->dev);
493 if (err) {
494 put_device(&devfreq->dev);
495 mutex_unlock(&devfreq->lock);
496 goto err_dev;
497 }
498
499 mutex_unlock(&devfreq->lock);
500
501 mutex_lock(&devfreq_list_lock);
502 list_add(&devfreq->node, &devfreq_list);
503
504 governor = find_devfreq_governor(devfreq->governor_name);
505 if (!IS_ERR(governor))
506 devfreq->governor = governor;
507 if (devfreq->governor)
508 err = devfreq->governor->event_handler(devfreq,
509 DEVFREQ_GOV_START, NULL);
510 mutex_unlock(&devfreq_list_lock);
511 if (err) {
512 dev_err(dev, "%s: Unable to start governor for the device\n",
513 __func__);
514 goto err_init;
515 }
516
517 return devfreq;
518
519err_init:
520 list_del(&devfreq->node);
521 device_unregister(&devfreq->dev);
522err_dev:
523 kfree(devfreq);
524err_out:
525 return ERR_PTR(err);
526}
527EXPORT_SYMBOL(devfreq_add_device);
528
529
530
531
532
533
534
535int devfreq_remove_device(struct devfreq *devfreq)
536{
537 if (!devfreq)
538 return -EINVAL;
539
540 device_unregister(&devfreq->dev);
541 put_device(&devfreq->dev);
542
543 return 0;
544}
545EXPORT_SYMBOL(devfreq_remove_device);
546
547static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
548{
549 struct devfreq **r = res;
550
551 if (WARN_ON(!r || !*r))
552 return 0;
553
554 return *r == data;
555}
556
557static void devm_devfreq_dev_release(struct device *dev, void *res)
558{
559 devfreq_remove_device(*(struct devfreq **)res);
560}
561
562
563
564
565
566
567
568
569
570
571
572
573
574struct devfreq *devm_devfreq_add_device(struct device *dev,
575 struct devfreq_dev_profile *profile,
576 const char *governor_name,
577 void *data)
578{
579 struct devfreq **ptr, *devfreq;
580
581 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
582 if (!ptr)
583 return ERR_PTR(-ENOMEM);
584
585 devfreq = devfreq_add_device(dev, profile, governor_name, data);
586 if (IS_ERR(devfreq)) {
587 devres_free(ptr);
588 return ERR_PTR(-ENOMEM);
589 }
590
591 *ptr = devfreq;
592 devres_add(dev, ptr);
593
594 return devfreq;
595}
596EXPORT_SYMBOL(devm_devfreq_add_device);
597
598
599
600
601
602
603void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
604{
605 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
606 devm_devfreq_dev_match, devfreq));
607}
608EXPORT_SYMBOL(devm_devfreq_remove_device);
609
610
611
612
613
614
615
616
617
618int devfreq_suspend_device(struct devfreq *devfreq)
619{
620 if (!devfreq)
621 return -EINVAL;
622
623 if (!devfreq->governor)
624 return 0;
625
626 return devfreq->governor->event_handler(devfreq,
627 DEVFREQ_GOV_SUSPEND, NULL);
628}
629EXPORT_SYMBOL(devfreq_suspend_device);
630
631
632
633
634
635
636
637
638
639int devfreq_resume_device(struct devfreq *devfreq)
640{
641 if (!devfreq)
642 return -EINVAL;
643
644 if (!devfreq->governor)
645 return 0;
646
647 return devfreq->governor->event_handler(devfreq,
648 DEVFREQ_GOV_RESUME, NULL);
649}
650EXPORT_SYMBOL(devfreq_resume_device);
651
652
653
654
655
656int devfreq_add_governor(struct devfreq_governor *governor)
657{
658 struct devfreq_governor *g;
659 struct devfreq *devfreq;
660 int err = 0;
661
662 if (!governor) {
663 pr_err("%s: Invalid parameters.\n", __func__);
664 return -EINVAL;
665 }
666
667 mutex_lock(&devfreq_list_lock);
668 g = find_devfreq_governor(governor->name);
669 if (!IS_ERR(g)) {
670 pr_err("%s: governor %s already registered\n", __func__,
671 g->name);
672 err = -EINVAL;
673 goto err_out;
674 }
675
676 list_add(&governor->node, &devfreq_governor_list);
677
678 list_for_each_entry(devfreq, &devfreq_list, node) {
679 int ret = 0;
680 struct device *dev = devfreq->dev.parent;
681
682 if (!strncmp(devfreq->governor_name, governor->name,
683 DEVFREQ_NAME_LEN)) {
684
685 if (devfreq->governor) {
686 dev_warn(dev,
687 "%s: Governor %s already present\n",
688 __func__, devfreq->governor->name);
689 ret = devfreq->governor->event_handler(devfreq,
690 DEVFREQ_GOV_STOP, NULL);
691 if (ret) {
692 dev_warn(dev,
693 "%s: Governor %s stop = %d\n",
694 __func__,
695 devfreq->governor->name, ret);
696 }
697
698 }
699 devfreq->governor = governor;
700 ret = devfreq->governor->event_handler(devfreq,
701 DEVFREQ_GOV_START, NULL);
702 if (ret) {
703 dev_warn(dev, "%s: Governor %s start=%d\n",
704 __func__, devfreq->governor->name,
705 ret);
706 }
707 }
708 }
709
710err_out:
711 mutex_unlock(&devfreq_list_lock);
712
713 return err;
714}
715EXPORT_SYMBOL(devfreq_add_governor);
716
717
718
719
720
721int devfreq_remove_governor(struct devfreq_governor *governor)
722{
723 struct devfreq_governor *g;
724 struct devfreq *devfreq;
725 int err = 0;
726
727 if (!governor) {
728 pr_err("%s: Invalid parameters.\n", __func__);
729 return -EINVAL;
730 }
731
732 mutex_lock(&devfreq_list_lock);
733 g = find_devfreq_governor(governor->name);
734 if (IS_ERR(g)) {
735 pr_err("%s: governor %s not registered\n", __func__,
736 governor->name);
737 err = PTR_ERR(g);
738 goto err_out;
739 }
740 list_for_each_entry(devfreq, &devfreq_list, node) {
741 int ret;
742 struct device *dev = devfreq->dev.parent;
743
744 if (!strncmp(devfreq->governor_name, governor->name,
745 DEVFREQ_NAME_LEN)) {
746
747 if (!devfreq->governor) {
748 dev_warn(dev, "%s: Governor %s NOT present\n",
749 __func__, governor->name);
750 continue;
751
752 }
753 ret = devfreq->governor->event_handler(devfreq,
754 DEVFREQ_GOV_STOP, NULL);
755 if (ret) {
756 dev_warn(dev, "%s: Governor %s stop=%d\n",
757 __func__, devfreq->governor->name,
758 ret);
759 }
760 devfreq->governor = NULL;
761 }
762 }
763
764 list_del(&governor->node);
765err_out:
766 mutex_unlock(&devfreq_list_lock);
767
768 return err;
769}
770EXPORT_SYMBOL(devfreq_remove_governor);
771
772static ssize_t governor_show(struct device *dev,
773 struct device_attribute *attr, char *buf)
774{
775 if (!to_devfreq(dev)->governor)
776 return -EINVAL;
777
778 return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
779}
780
781static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
782 const char *buf, size_t count)
783{
784 struct devfreq *df = to_devfreq(dev);
785 int ret;
786 char str_governor[DEVFREQ_NAME_LEN + 1];
787 struct devfreq_governor *governor;
788
789 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
790 if (ret != 1)
791 return -EINVAL;
792
793 mutex_lock(&devfreq_list_lock);
794 governor = find_devfreq_governor(str_governor);
795 if (IS_ERR(governor)) {
796 ret = PTR_ERR(governor);
797 goto out;
798 }
799 if (df->governor == governor)
800 goto out;
801
802 if (df->governor) {
803 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
804 if (ret) {
805 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
806 __func__, df->governor->name, ret);
807 goto out;
808 }
809 }
810 df->governor = governor;
811 strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
812 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
813 if (ret)
814 dev_warn(dev, "%s: Governor %s not started(%d)\n",
815 __func__, df->governor->name, ret);
816out:
817 mutex_unlock(&devfreq_list_lock);
818
819 if (!ret)
820 ret = count;
821 return ret;
822}
823static DEVICE_ATTR_RW(governor);
824
825static ssize_t available_governors_show(struct device *d,
826 struct device_attribute *attr,
827 char *buf)
828{
829 struct devfreq_governor *tmp_governor;
830 ssize_t count = 0;
831
832 mutex_lock(&devfreq_list_lock);
833 list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
834 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
835 "%s ", tmp_governor->name);
836 mutex_unlock(&devfreq_list_lock);
837
838
839 if (count)
840 count--;
841
842 count += sprintf(&buf[count], "\n");
843
844 return count;
845}
846static DEVICE_ATTR_RO(available_governors);
847
848static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
849 char *buf)
850{
851 unsigned long freq;
852 struct devfreq *devfreq = to_devfreq(dev);
853
854 if (devfreq->profile->get_cur_freq &&
855 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
856 return sprintf(buf, "%lu\n", freq);
857
858 return sprintf(buf, "%lu\n", devfreq->previous_freq);
859}
860static DEVICE_ATTR_RO(cur_freq);
861
862static ssize_t target_freq_show(struct device *dev,
863 struct device_attribute *attr, char *buf)
864{
865 return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
866}
867static DEVICE_ATTR_RO(target_freq);
868
869static ssize_t polling_interval_show(struct device *dev,
870 struct device_attribute *attr, char *buf)
871{
872 return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
873}
874
875static ssize_t polling_interval_store(struct device *dev,
876 struct device_attribute *attr,
877 const char *buf, size_t count)
878{
879 struct devfreq *df = to_devfreq(dev);
880 unsigned int value;
881 int ret;
882
883 if (!df->governor)
884 return -EINVAL;
885
886 ret = sscanf(buf, "%u", &value);
887 if (ret != 1)
888 return -EINVAL;
889
890 df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value);
891 ret = count;
892
893 return ret;
894}
895static DEVICE_ATTR_RW(polling_interval);
896
897static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
898 const char *buf, size_t count)
899{
900 struct devfreq *df = to_devfreq(dev);
901 unsigned long value;
902 int ret;
903 unsigned long max;
904
905 ret = sscanf(buf, "%lu", &value);
906 if (ret != 1)
907 return -EINVAL;
908
909 mutex_lock(&df->lock);
910 max = df->max_freq;
911 if (value && max && value > max) {
912 ret = -EINVAL;
913 goto unlock;
914 }
915
916 df->min_freq = value;
917 update_devfreq(df);
918 ret = count;
919unlock:
920 mutex_unlock(&df->lock);
921 return ret;
922}
923
924static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
925 char *buf)
926{
927 return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
928}
929
930static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
931 const char *buf, size_t count)
932{
933 struct devfreq *df = to_devfreq(dev);
934 unsigned long value;
935 int ret;
936 unsigned long min;
937
938 ret = sscanf(buf, "%lu", &value);
939 if (ret != 1)
940 return -EINVAL;
941
942 mutex_lock(&df->lock);
943 min = df->min_freq;
944 if (value && min && value < min) {
945 ret = -EINVAL;
946 goto unlock;
947 }
948
949 df->max_freq = value;
950 update_devfreq(df);
951 ret = count;
952unlock:
953 mutex_unlock(&df->lock);
954 return ret;
955}
956static DEVICE_ATTR_RW(min_freq);
957
958static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
959 char *buf)
960{
961 return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
962}
963static DEVICE_ATTR_RW(max_freq);
964
965static ssize_t available_frequencies_show(struct device *d,
966 struct device_attribute *attr,
967 char *buf)
968{
969 struct devfreq *df = to_devfreq(d);
970 struct device *dev = df->dev.parent;
971 struct dev_pm_opp *opp;
972 ssize_t count = 0;
973 unsigned long freq = 0;
974
975 rcu_read_lock();
976 do {
977 opp = dev_pm_opp_find_freq_ceil(dev, &freq);
978 if (IS_ERR(opp))
979 break;
980
981 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
982 "%lu ", freq);
983 freq++;
984 } while (1);
985 rcu_read_unlock();
986
987
988 if (count)
989 count--;
990
991 count += sprintf(&buf[count], "\n");
992
993 return count;
994}
995static DEVICE_ATTR_RO(available_frequencies);
996
997static ssize_t trans_stat_show(struct device *dev,
998 struct device_attribute *attr, char *buf)
999{
1000 struct devfreq *devfreq = to_devfreq(dev);
1001 ssize_t len;
1002 int i, j;
1003 unsigned int max_state = devfreq->profile->max_state;
1004
1005 if (!devfreq->stop_polling &&
1006 devfreq_update_status(devfreq, devfreq->previous_freq))
1007 return 0;
1008
1009 len = sprintf(buf, " From : To\n");
1010 len += sprintf(buf + len, " :");
1011 for (i = 0; i < max_state; i++)
1012 len += sprintf(buf + len, "%8u",
1013 devfreq->profile->freq_table[i]);
1014
1015 len += sprintf(buf + len, " time(ms)\n");
1016
1017 for (i = 0; i < max_state; i++) {
1018 if (devfreq->profile->freq_table[i]
1019 == devfreq->previous_freq) {
1020 len += sprintf(buf + len, "*");
1021 } else {
1022 len += sprintf(buf + len, " ");
1023 }
1024 len += sprintf(buf + len, "%8u:",
1025 devfreq->profile->freq_table[i]);
1026 for (j = 0; j < max_state; j++)
1027 len += sprintf(buf + len, "%8u",
1028 devfreq->trans_table[(i * max_state) + j]);
1029 len += sprintf(buf + len, "%10u\n",
1030 jiffies_to_msecs(devfreq->time_in_state[i]));
1031 }
1032
1033 len += sprintf(buf + len, "Total transition : %u\n",
1034 devfreq->total_trans);
1035 return len;
1036}
1037static DEVICE_ATTR_RO(trans_stat);
1038
1039static struct attribute *devfreq_attrs[] = {
1040 &dev_attr_governor.attr,
1041 &dev_attr_available_governors.attr,
1042 &dev_attr_cur_freq.attr,
1043 &dev_attr_available_frequencies.attr,
1044 &dev_attr_target_freq.attr,
1045 &dev_attr_polling_interval.attr,
1046 &dev_attr_min_freq.attr,
1047 &dev_attr_max_freq.attr,
1048 &dev_attr_trans_stat.attr,
1049 NULL,
1050};
1051ATTRIBUTE_GROUPS(devfreq);
1052
1053static int __init devfreq_init(void)
1054{
1055 devfreq_class = class_create(THIS_MODULE, "devfreq");
1056 if (IS_ERR(devfreq_class)) {
1057 pr_err("%s: couldn't create class\n", __FILE__);
1058 return PTR_ERR(devfreq_class);
1059 }
1060
1061 devfreq_wq = create_freezable_workqueue("devfreq_wq");
1062 if (!devfreq_wq) {
1063 class_destroy(devfreq_class);
1064 pr_err("%s: couldn't create workqueue\n", __FILE__);
1065 return -ENOMEM;
1066 }
1067 devfreq_class->dev_groups = devfreq_groups;
1068
1069 return 0;
1070}
1071subsys_initcall(devfreq_init);
1072
1073static void __exit devfreq_exit(void)
1074{
1075 class_destroy(devfreq_class);
1076 destroy_workqueue(devfreq_wq);
1077}
1078module_exit(devfreq_exit);
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
1099 unsigned long *freq,
1100 u32 flags)
1101{
1102 struct dev_pm_opp *opp;
1103
1104 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
1105
1106 opp = dev_pm_opp_find_freq_floor(dev, freq);
1107
1108
1109 if (opp == ERR_PTR(-ERANGE))
1110 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1111 } else {
1112
1113 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1114
1115
1116 if (opp == ERR_PTR(-ERANGE))
1117 opp = dev_pm_opp_find_freq_floor(dev, freq);
1118 }
1119
1120 return opp;
1121}
1122
1123
1124
1125
1126
1127
1128
1129
1130int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
1131{
1132 struct srcu_notifier_head *nh;
1133 int ret = 0;
1134
1135 rcu_read_lock();
1136 nh = dev_pm_opp_get_notifier(dev);
1137 if (IS_ERR(nh))
1138 ret = PTR_ERR(nh);
1139 rcu_read_unlock();
1140 if (!ret)
1141 ret = srcu_notifier_chain_register(nh, &devfreq->nb);
1142
1143 return ret;
1144}
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
1157{
1158 struct srcu_notifier_head *nh;
1159 int ret = 0;
1160
1161 rcu_read_lock();
1162 nh = dev_pm_opp_get_notifier(dev);
1163 if (IS_ERR(nh))
1164 ret = PTR_ERR(nh);
1165 rcu_read_unlock();
1166 if (!ret)
1167 ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
1168
1169 return ret;
1170}
1171
1172static void devm_devfreq_opp_release(struct device *dev, void *res)
1173{
1174 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
1175}
1176
1177
1178
1179
1180
1181
1182
1183int devm_devfreq_register_opp_notifier(struct device *dev,
1184 struct devfreq *devfreq)
1185{
1186 struct devfreq **ptr;
1187 int ret;
1188
1189 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
1190 if (!ptr)
1191 return -ENOMEM;
1192
1193 ret = devfreq_register_opp_notifier(dev, devfreq);
1194 if (ret) {
1195 devres_free(ptr);
1196 return ret;
1197 }
1198
1199 *ptr = devfreq;
1200 devres_add(dev, ptr);
1201
1202 return 0;
1203}
1204EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
1205
1206
1207
1208
1209
1210
1211
1212void devm_devfreq_unregister_opp_notifier(struct device *dev,
1213 struct devfreq *devfreq)
1214{
1215 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
1216 devm_devfreq_dev_match, devfreq));
1217}
1218EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
1219
1220MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1221MODULE_DESCRIPTION("devfreq class support");
1222MODULE_LICENSE("GPL");
1223