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