1 // SPDX-License-Identifier: GPL-2.0-only
3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
6 * Copyright (C) 2011 Samsung Electronics
7 * MyungJoo Ham <myungjoo.ham@samsung.com>
10 #include <linux/kernel.h>
11 #include <linux/kmod.h>
12 #include <linux/sched.h>
13 #include <linux/debugfs.h>
14 #include <linux/errno.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/export.h>
18 #include <linux/slab.h>
19 #include <linux/stat.h>
20 #include <linux/pm_opp.h>
21 #include <linux/devfreq.h>
22 #include <linux/workqueue.h>
23 #include <linux/platform_device.h>
24 #include <linux/list.h>
25 #include <linux/printk.h>
26 #include <linux/hrtimer.h>
28 #include <linux/pm_qos.h>
31 #define CREATE_TRACE_POINTS
32 #include <trace/events/devfreq.h>
34 #define HZ_PER_KHZ 1000
36 static struct class *devfreq_class;
37 static struct dentry *devfreq_debugfs;
40 * devfreq core provides delayed work based load monitoring helper
41 * functions. Governors can use these or can implement their own
42 * monitoring mechanism.
44 static struct workqueue_struct *devfreq_wq;
46 /* The list of all device-devfreq governors */
47 static LIST_HEAD(devfreq_governor_list);
48 /* The list of all device-devfreq */
49 static LIST_HEAD(devfreq_list);
50 static DEFINE_MUTEX(devfreq_list_lock);
52 static const char timer_name[][DEVFREQ_NAME_LEN] = {
53 [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" },
54 [DEVFREQ_TIMER_DELAYED] = { "delayed" },
58 * find_device_devfreq() - find devfreq struct using device pointer
59 * @dev: device pointer used to lookup device devfreq.
61 * Search the list of device devfreqs and return the matched device's
62 * devfreq info. devfreq_list_lock should be held by the caller.
64 static struct devfreq *find_device_devfreq(struct device *dev)
66 struct devfreq *tmp_devfreq;
68 lockdep_assert_held(&devfreq_list_lock);
70 if (IS_ERR_OR_NULL(dev)) {
71 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
72 return ERR_PTR(-EINVAL);
75 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
76 if (tmp_devfreq->dev.parent == dev)
80 return ERR_PTR(-ENODEV);
83 static unsigned long find_available_min_freq(struct devfreq *devfreq)
85 struct dev_pm_opp *opp;
86 unsigned long min_freq = 0;
88 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq);
97 static unsigned long find_available_max_freq(struct devfreq *devfreq)
99 struct dev_pm_opp *opp;
100 unsigned long max_freq = ULONG_MAX;
102 opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq);
112 * get_freq_range() - Get the current freq range
113 * @devfreq: the devfreq instance
114 * @min_freq: the min frequency
115 * @max_freq: the max frequency
117 * This takes into consideration all constraints.
119 static void get_freq_range(struct devfreq *devfreq,
120 unsigned long *min_freq,
121 unsigned long *max_freq)
123 unsigned long *freq_table = devfreq->profile->freq_table;
124 s32 qos_min_freq, qos_max_freq;
126 lockdep_assert_held(&devfreq->lock);
129 * Initialize minimum/maximum frequency from freq table.
130 * The devfreq drivers can initialize this in either ascending or
131 * descending order and devfreq core supports both.
133 if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) {
134 *min_freq = freq_table[0];
135 *max_freq = freq_table[devfreq->profile->max_state - 1];
137 *min_freq = freq_table[devfreq->profile->max_state - 1];
138 *max_freq = freq_table[0];
141 /* Apply constraints from PM QoS */
142 qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,
143 DEV_PM_QOS_MIN_FREQUENCY);
144 qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,
145 DEV_PM_QOS_MAX_FREQUENCY);
146 *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);
147 if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)
148 *max_freq = min(*max_freq,
149 (unsigned long)HZ_PER_KHZ * qos_max_freq);
151 /* Apply constraints from OPP interface */
152 *min_freq = max(*min_freq, devfreq->scaling_min_freq);
153 *max_freq = min(*max_freq, devfreq->scaling_max_freq);
155 if (*min_freq > *max_freq)
156 *min_freq = *max_freq;
160 * devfreq_get_freq_level() - Lookup freq_table for the frequency
161 * @devfreq: the devfreq instance
162 * @freq: the target frequency
164 static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
168 for (lev = 0; lev < devfreq->profile->max_state; lev++)
169 if (freq == devfreq->profile->freq_table[lev])
175 static int set_freq_table(struct devfreq *devfreq)
177 struct devfreq_dev_profile *profile = devfreq->profile;
178 struct dev_pm_opp *opp;
182 /* Initialize the freq_table from OPP table */
183 count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
187 profile->max_state = count;
188 profile->freq_table = devm_kcalloc(devfreq->dev.parent,
190 sizeof(*profile->freq_table),
192 if (!profile->freq_table) {
193 profile->max_state = 0;
197 for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
198 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
200 devm_kfree(devfreq->dev.parent, profile->freq_table);
201 profile->max_state = 0;
205 profile->freq_table[i] = freq;
212 * devfreq_update_status() - Update statistics of devfreq behavior
213 * @devfreq: the devfreq instance
214 * @freq: the update target frequency
216 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
218 int lev, prev_lev, ret = 0;
221 lockdep_assert_held(&devfreq->lock);
222 cur_time = get_jiffies_64();
224 /* Immediately exit if previous_freq is not initialized yet. */
225 if (!devfreq->previous_freq)
228 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
234 devfreq->stats.time_in_state[prev_lev] +=
235 cur_time - devfreq->stats.last_update;
237 lev = devfreq_get_freq_level(devfreq, freq);
243 if (lev != prev_lev) {
244 devfreq->stats.trans_table[
245 (prev_lev * devfreq->profile->max_state) + lev]++;
246 devfreq->stats.total_trans++;
250 devfreq->stats.last_update = cur_time;
253 EXPORT_SYMBOL(devfreq_update_status);
256 * find_devfreq_governor() - find devfreq governor from name
257 * @name: name of the governor
259 * Search the list of devfreq governors and return the matched
260 * governor's pointer. devfreq_list_lock should be held by the caller.
262 static struct devfreq_governor *find_devfreq_governor(const char *name)
264 struct devfreq_governor *tmp_governor;
266 lockdep_assert_held(&devfreq_list_lock);
268 if (IS_ERR_OR_NULL(name)) {
269 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
270 return ERR_PTR(-EINVAL);
273 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
274 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
278 return ERR_PTR(-ENODEV);
282 * try_then_request_governor() - Try to find the governor and request the
283 * module if is not found.
284 * @name: name of the governor
286 * Search the list of devfreq governors and request the module and try again
287 * if is not found. This can happen when both drivers (the governor driver
288 * and the driver that call devfreq_add_device) are built as modules.
289 * devfreq_list_lock should be held by the caller. Returns the matched
290 * governor's pointer or an error pointer.
292 static struct devfreq_governor *try_then_request_governor(const char *name)
294 struct devfreq_governor *governor;
297 lockdep_assert_held(&devfreq_list_lock);
299 if (IS_ERR_OR_NULL(name)) {
300 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
301 return ERR_PTR(-EINVAL);
304 governor = find_devfreq_governor(name);
305 if (IS_ERR(governor)) {
306 mutex_unlock(&devfreq_list_lock);
308 if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND,
310 err = request_module("governor_%s", "simpleondemand");
312 err = request_module("governor_%s", name);
313 /* Restore previous state before return */
314 mutex_lock(&devfreq_list_lock);
316 return (err < 0) ? ERR_PTR(err) : ERR_PTR(-EINVAL);
318 governor = find_devfreq_governor(name);
324 static int devfreq_notify_transition(struct devfreq *devfreq,
325 struct devfreq_freqs *freqs, unsigned int state)
331 case DEVFREQ_PRECHANGE:
332 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
333 DEVFREQ_PRECHANGE, freqs);
336 case DEVFREQ_POSTCHANGE:
337 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
338 DEVFREQ_POSTCHANGE, freqs);
347 static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
350 struct devfreq_freqs freqs;
351 unsigned long cur_freq;
354 if (devfreq->profile->get_cur_freq)
355 devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
357 cur_freq = devfreq->previous_freq;
359 freqs.old = cur_freq;
360 freqs.new = new_freq;
361 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
363 err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
365 freqs.new = cur_freq;
366 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
370 freqs.new = new_freq;
371 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
373 if (devfreq_update_status(devfreq, new_freq))
374 dev_err(&devfreq->dev,
375 "Couldn't update frequency transition information.\n");
377 devfreq->previous_freq = new_freq;
379 if (devfreq->suspend_freq)
380 devfreq->resume_freq = new_freq;
385 /* Load monitoring helper functions for governors use */
388 * update_devfreq() - Reevaluate the device and configure frequency.
389 * @devfreq: the devfreq instance.
391 * Note: Lock devfreq->lock before calling update_devfreq
392 * This function is exported for governors.
394 int update_devfreq(struct devfreq *devfreq)
396 unsigned long freq, min_freq, max_freq;
400 lockdep_assert_held(&devfreq->lock);
402 if (!devfreq->governor)
405 /* Reevaluate the proper frequency */
406 err = devfreq->governor->get_target_freq(devfreq, &freq);
409 get_freq_range(devfreq, &min_freq, &max_freq);
411 if (freq < min_freq) {
413 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
415 if (freq > max_freq) {
417 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
420 return devfreq_set_target(devfreq, freq, flags);
423 EXPORT_SYMBOL(update_devfreq);
426 * devfreq_monitor() - Periodically poll devfreq objects.
427 * @work: the work struct used to run devfreq_monitor periodically.
430 static void devfreq_monitor(struct work_struct *work)
433 struct devfreq *devfreq = container_of(work,
434 struct devfreq, work.work);
436 mutex_lock(&devfreq->lock);
437 err = update_devfreq(devfreq);
439 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
441 queue_delayed_work(devfreq_wq, &devfreq->work,
442 msecs_to_jiffies(devfreq->profile->polling_ms));
443 mutex_unlock(&devfreq->lock);
445 trace_devfreq_monitor(devfreq);
449 * devfreq_monitor_start() - Start load monitoring of devfreq instance
450 * @devfreq: the devfreq instance.
452 * Helper function for starting devfreq device load monitoring. By
453 * default delayed work based monitoring is supported. Function
454 * to be called from governor in response to DEVFREQ_GOV_START
455 * event when device is added to devfreq framework.
457 void devfreq_monitor_start(struct devfreq *devfreq)
459 if (devfreq->governor->interrupt_driven)
462 switch (devfreq->profile->timer) {
463 case DEVFREQ_TIMER_DEFERRABLE:
464 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
466 case DEVFREQ_TIMER_DELAYED:
467 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
473 if (devfreq->profile->polling_ms)
474 queue_delayed_work(devfreq_wq, &devfreq->work,
475 msecs_to_jiffies(devfreq->profile->polling_ms));
477 EXPORT_SYMBOL(devfreq_monitor_start);
480 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
481 * @devfreq: the devfreq instance.
483 * Helper function to stop devfreq device load monitoring. Function
484 * to be called from governor in response to DEVFREQ_GOV_STOP
485 * event when device is removed from devfreq framework.
487 void devfreq_monitor_stop(struct devfreq *devfreq)
489 if (devfreq->governor->interrupt_driven)
492 cancel_delayed_work_sync(&devfreq->work);
494 EXPORT_SYMBOL(devfreq_monitor_stop);
497 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
498 * @devfreq: the devfreq instance.
500 * Helper function to suspend devfreq device load monitoring. Function
501 * to be called from governor in response to DEVFREQ_GOV_SUSPEND
502 * event or when polling interval is set to zero.
504 * Note: Though this function is same as devfreq_monitor_stop(),
505 * intentionally kept separate to provide hooks for collecting
506 * transition statistics.
508 void devfreq_monitor_suspend(struct devfreq *devfreq)
510 mutex_lock(&devfreq->lock);
511 if (devfreq->stop_polling) {
512 mutex_unlock(&devfreq->lock);
516 devfreq_update_status(devfreq, devfreq->previous_freq);
517 devfreq->stop_polling = true;
518 mutex_unlock(&devfreq->lock);
520 if (devfreq->governor->interrupt_driven)
523 cancel_delayed_work_sync(&devfreq->work);
525 EXPORT_SYMBOL(devfreq_monitor_suspend);
528 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
529 * @devfreq: the devfreq instance.
531 * Helper function to resume devfreq device load monitoring. Function
532 * to be called from governor in response to DEVFREQ_GOV_RESUME
533 * event or when polling interval is set to non-zero.
535 void devfreq_monitor_resume(struct devfreq *devfreq)
539 mutex_lock(&devfreq->lock);
540 if (!devfreq->stop_polling)
543 if (devfreq->governor->interrupt_driven)
546 if (!delayed_work_pending(&devfreq->work) &&
547 devfreq->profile->polling_ms)
548 queue_delayed_work(devfreq_wq, &devfreq->work,
549 msecs_to_jiffies(devfreq->profile->polling_ms));
552 devfreq->stats.last_update = get_jiffies_64();
553 devfreq->stop_polling = false;
555 if (devfreq->profile->get_cur_freq &&
556 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
557 devfreq->previous_freq = freq;
560 mutex_unlock(&devfreq->lock);
562 EXPORT_SYMBOL(devfreq_monitor_resume);
565 * devfreq_update_interval() - Update device devfreq monitoring interval
566 * @devfreq: the devfreq instance.
567 * @delay: new polling interval to be set.
569 * Helper function to set new load monitoring polling interval. Function
570 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.
572 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)
574 unsigned int cur_delay = devfreq->profile->polling_ms;
575 unsigned int new_delay = *delay;
577 mutex_lock(&devfreq->lock);
578 devfreq->profile->polling_ms = new_delay;
580 if (devfreq->stop_polling)
583 if (devfreq->governor->interrupt_driven)
586 /* if new delay is zero, stop polling */
588 mutex_unlock(&devfreq->lock);
589 cancel_delayed_work_sync(&devfreq->work);
593 /* if current delay is zero, start polling with new delay */
595 queue_delayed_work(devfreq_wq, &devfreq->work,
596 msecs_to_jiffies(devfreq->profile->polling_ms));
600 /* if current delay is greater than new delay, restart polling */
601 if (cur_delay > new_delay) {
602 mutex_unlock(&devfreq->lock);
603 cancel_delayed_work_sync(&devfreq->work);
604 mutex_lock(&devfreq->lock);
605 if (!devfreq->stop_polling)
606 queue_delayed_work(devfreq_wq, &devfreq->work,
607 msecs_to_jiffies(devfreq->profile->polling_ms));
610 mutex_unlock(&devfreq->lock);
612 EXPORT_SYMBOL(devfreq_update_interval);
615 * devfreq_notifier_call() - Notify that the device frequency requirements
616 * has been changed out of devfreq framework.
617 * @nb: the notifier_block (supposed to be devfreq->nb)
621 * Called by a notifier that uses devfreq->nb.
623 static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
626 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
629 mutex_lock(&devfreq->lock);
631 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
632 if (!devfreq->scaling_min_freq)
635 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
636 if (!devfreq->scaling_max_freq) {
637 devfreq->scaling_max_freq = ULONG_MAX;
641 err = update_devfreq(devfreq);
644 mutex_unlock(&devfreq->lock);
646 dev_err(devfreq->dev.parent,
647 "failed to update frequency from OPP notifier (%d)\n",
654 * qos_notifier_call() - Common handler for QoS constraints.
655 * @devfreq: the devfreq instance.
657 static int qos_notifier_call(struct devfreq *devfreq)
661 mutex_lock(&devfreq->lock);
662 err = update_devfreq(devfreq);
663 mutex_unlock(&devfreq->lock);
665 dev_err(devfreq->dev.parent,
666 "failed to update frequency from PM QoS (%d)\n",
673 * qos_min_notifier_call() - Callback for QoS min_freq changes.
674 * @nb: Should be devfreq->nb_min
676 static int qos_min_notifier_call(struct notifier_block *nb,
677 unsigned long val, void *ptr)
679 return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
683 * qos_max_notifier_call() - Callback for QoS max_freq changes.
684 * @nb: Should be devfreq->nb_max
686 static int qos_max_notifier_call(struct notifier_block *nb,
687 unsigned long val, void *ptr)
689 return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
693 * devfreq_dev_release() - Callback for struct device to release the device.
694 * @dev: the devfreq device
696 * Remove devfreq from the list and release its resources.
698 static void devfreq_dev_release(struct device *dev)
700 struct devfreq *devfreq = to_devfreq(dev);
703 mutex_lock(&devfreq_list_lock);
704 list_del(&devfreq->node);
705 mutex_unlock(&devfreq_list_lock);
707 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
708 DEV_PM_QOS_MAX_FREQUENCY);
709 if (err && err != -ENOENT)
710 dev_warn(dev->parent,
711 "Failed to remove max_freq notifier: %d\n", err);
712 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
713 DEV_PM_QOS_MIN_FREQUENCY);
714 if (err && err != -ENOENT)
715 dev_warn(dev->parent,
716 "Failed to remove min_freq notifier: %d\n", err);
718 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
719 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
721 dev_warn(dev->parent,
722 "Failed to remove max_freq request: %d\n", err);
724 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
725 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
727 dev_warn(dev->parent,
728 "Failed to remove min_freq request: %d\n", err);
731 if (devfreq->profile->exit)
732 devfreq->profile->exit(devfreq->dev.parent);
734 mutex_destroy(&devfreq->lock);
739 * devfreq_add_device() - Add devfreq feature to the device
740 * @dev: the device to add devfreq feature.
741 * @profile: device-specific profile to run devfreq.
742 * @governor_name: name of the policy to choose frequency.
743 * @data: private data for the governor. The devfreq framework does not
746 struct devfreq *devfreq_add_device(struct device *dev,
747 struct devfreq_dev_profile *profile,
748 const char *governor_name,
751 struct devfreq *devfreq;
752 struct devfreq_governor *governor;
755 if (!dev || !profile || !governor_name) {
756 dev_err(dev, "%s: Invalid parameters.\n", __func__);
757 return ERR_PTR(-EINVAL);
760 mutex_lock(&devfreq_list_lock);
761 devfreq = find_device_devfreq(dev);
762 mutex_unlock(&devfreq_list_lock);
763 if (!IS_ERR(devfreq)) {
764 dev_err(dev, "%s: devfreq device already exists!\n",
770 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
776 mutex_init(&devfreq->lock);
777 mutex_lock(&devfreq->lock);
778 devfreq->dev.parent = dev;
779 devfreq->dev.class = devfreq_class;
780 devfreq->dev.release = devfreq_dev_release;
781 INIT_LIST_HEAD(&devfreq->node);
782 devfreq->profile = profile;
783 strscpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
784 devfreq->previous_freq = profile->initial_freq;
785 devfreq->last_status.current_frequency = profile->initial_freq;
786 devfreq->data = data;
787 devfreq->nb.notifier_call = devfreq_notifier_call;
789 if (devfreq->profile->timer < 0
790 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {
791 mutex_unlock(&devfreq->lock);
796 if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
797 mutex_unlock(&devfreq->lock);
798 err = set_freq_table(devfreq);
801 mutex_lock(&devfreq->lock);
804 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
805 if (!devfreq->scaling_min_freq) {
806 mutex_unlock(&devfreq->lock);
811 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
812 if (!devfreq->scaling_max_freq) {
813 mutex_unlock(&devfreq->lock);
818 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
819 atomic_set(&devfreq->suspend_count, 0);
821 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
822 err = device_register(&devfreq->dev);
824 mutex_unlock(&devfreq->lock);
825 put_device(&devfreq->dev);
829 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
830 array3_size(sizeof(unsigned int),
831 devfreq->profile->max_state,
832 devfreq->profile->max_state),
834 if (!devfreq->stats.trans_table) {
835 mutex_unlock(&devfreq->lock);
840 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
841 devfreq->profile->max_state,
842 sizeof(*devfreq->stats.time_in_state),
844 if (!devfreq->stats.time_in_state) {
845 mutex_unlock(&devfreq->lock);
850 devfreq->stats.total_trans = 0;
851 devfreq->stats.last_update = get_jiffies_64();
853 srcu_init_notifier_head(&devfreq->transition_notifier_list);
855 mutex_unlock(&devfreq->lock);
857 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
858 DEV_PM_QOS_MIN_FREQUENCY, 0);
861 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
862 DEV_PM_QOS_MAX_FREQUENCY,
863 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
867 devfreq->nb_min.notifier_call = qos_min_notifier_call;
868 err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min,
869 DEV_PM_QOS_MIN_FREQUENCY);
873 devfreq->nb_max.notifier_call = qos_max_notifier_call;
874 err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max,
875 DEV_PM_QOS_MAX_FREQUENCY);
879 mutex_lock(&devfreq_list_lock);
881 governor = try_then_request_governor(devfreq->governor_name);
882 if (IS_ERR(governor)) {
883 dev_err(dev, "%s: Unable to find governor for the device\n",
885 err = PTR_ERR(governor);
889 devfreq->governor = governor;
890 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
893 dev_err(dev, "%s: Unable to start governor for the device\n",
898 list_add(&devfreq->node, &devfreq_list);
900 mutex_unlock(&devfreq_list_lock);
905 mutex_unlock(&devfreq_list_lock);
907 devfreq_remove_device(devfreq);
914 EXPORT_SYMBOL(devfreq_add_device);
917 * devfreq_remove_device() - Remove devfreq feature from a device.
918 * @devfreq: the devfreq instance to be removed
920 * The opposite of devfreq_add_device().
922 int devfreq_remove_device(struct devfreq *devfreq)
927 if (devfreq->governor)
928 devfreq->governor->event_handler(devfreq,
929 DEVFREQ_GOV_STOP, NULL);
930 device_unregister(&devfreq->dev);
934 EXPORT_SYMBOL(devfreq_remove_device);
936 static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
938 struct devfreq **r = res;
940 if (WARN_ON(!r || !*r))
946 static void devm_devfreq_dev_release(struct device *dev, void *res)
948 devfreq_remove_device(*(struct devfreq **)res);
952 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
953 * @dev: the device to add devfreq feature.
954 * @profile: device-specific profile to run devfreq.
955 * @governor_name: name of the policy to choose frequency.
956 * @data: private data for the governor. The devfreq framework does not
959 * This function manages automatically the memory of devfreq device using device
960 * resource management and simplify the free operation for memory of devfreq
963 struct devfreq *devm_devfreq_add_device(struct device *dev,
964 struct devfreq_dev_profile *profile,
965 const char *governor_name,
968 struct devfreq **ptr, *devfreq;
970 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
972 return ERR_PTR(-ENOMEM);
974 devfreq = devfreq_add_device(dev, profile, governor_name, data);
975 if (IS_ERR(devfreq)) {
981 devres_add(dev, ptr);
985 EXPORT_SYMBOL(devm_devfreq_add_device);
989 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree
990 * @node - pointer to device_node
992 * return the instance of devfreq device
994 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
996 struct devfreq *devfreq;
999 return ERR_PTR(-EINVAL);
1001 mutex_lock(&devfreq_list_lock);
1002 list_for_each_entry(devfreq, &devfreq_list, node) {
1003 if (devfreq->dev.parent
1004 && devfreq->dev.parent->of_node == node) {
1005 mutex_unlock(&devfreq_list_lock);
1009 mutex_unlock(&devfreq_list_lock);
1011 return ERR_PTR(-ENODEV);
1015 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
1016 * @dev - instance to the given device
1017 * @phandle_name - name of property holding a phandle value
1018 * @index - index into list of devfreq
1020 * return the instance of devfreq device
1022 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1023 const char *phandle_name, int index)
1025 struct device_node *node;
1026 struct devfreq *devfreq;
1028 if (!dev || !phandle_name)
1029 return ERR_PTR(-EINVAL);
1032 return ERR_PTR(-EINVAL);
1034 node = of_parse_phandle(dev->of_node, phandle_name, index);
1036 return ERR_PTR(-ENODEV);
1038 devfreq = devfreq_get_devfreq_by_node(node);
1045 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1047 return ERR_PTR(-ENODEV);
1050 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1051 const char *phandle_name, int index)
1053 return ERR_PTR(-ENODEV);
1055 #endif /* CONFIG_OF */
1056 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
1057 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
1060 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
1061 * @dev: the device from which to remove devfreq feature.
1062 * @devfreq: the devfreq instance to be removed
1064 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
1066 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
1067 devm_devfreq_dev_match, devfreq));
1069 EXPORT_SYMBOL(devm_devfreq_remove_device);
1072 * devfreq_suspend_device() - Suspend devfreq of a device.
1073 * @devfreq: the devfreq instance to be suspended
1075 * This function is intended to be called by the pm callbacks
1076 * (e.g., runtime_suspend, suspend) of the device driver that
1077 * holds the devfreq.
1079 int devfreq_suspend_device(struct devfreq *devfreq)
1086 if (atomic_inc_return(&devfreq->suspend_count) > 1)
1089 if (devfreq->governor) {
1090 ret = devfreq->governor->event_handler(devfreq,
1091 DEVFREQ_GOV_SUSPEND, NULL);
1096 if (devfreq->suspend_freq) {
1097 mutex_lock(&devfreq->lock);
1098 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
1099 mutex_unlock(&devfreq->lock);
1106 EXPORT_SYMBOL(devfreq_suspend_device);
1109 * devfreq_resume_device() - Resume devfreq of a device.
1110 * @devfreq: the devfreq instance to be resumed
1112 * This function is intended to be called by the pm callbacks
1113 * (e.g., runtime_resume, resume) of the device driver that
1114 * holds the devfreq.
1116 int devfreq_resume_device(struct devfreq *devfreq)
1123 if (atomic_dec_return(&devfreq->suspend_count) >= 1)
1126 if (devfreq->resume_freq) {
1127 mutex_lock(&devfreq->lock);
1128 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
1129 mutex_unlock(&devfreq->lock);
1134 if (devfreq->governor) {
1135 ret = devfreq->governor->event_handler(devfreq,
1136 DEVFREQ_GOV_RESUME, NULL);
1143 EXPORT_SYMBOL(devfreq_resume_device);
1146 * devfreq_suspend() - Suspend devfreq governors and devices
1148 * Called during system wide Suspend/Hibernate cycles for suspending governors
1149 * and devices preserving the state for resume. On some platforms the devfreq
1150 * device must have precise state (frequency) after resume in order to provide
1151 * fully operating setup.
1153 void devfreq_suspend(void)
1155 struct devfreq *devfreq;
1158 mutex_lock(&devfreq_list_lock);
1159 list_for_each_entry(devfreq, &devfreq_list, node) {
1160 ret = devfreq_suspend_device(devfreq);
1162 dev_err(&devfreq->dev,
1163 "failed to suspend devfreq device\n");
1165 mutex_unlock(&devfreq_list_lock);
1169 * devfreq_resume() - Resume devfreq governors and devices
1171 * Called during system wide Suspend/Hibernate cycle for resuming governors and
1172 * devices that are suspended with devfreq_suspend().
1174 void devfreq_resume(void)
1176 struct devfreq *devfreq;
1179 mutex_lock(&devfreq_list_lock);
1180 list_for_each_entry(devfreq, &devfreq_list, node) {
1181 ret = devfreq_resume_device(devfreq);
1183 dev_warn(&devfreq->dev,
1184 "failed to resume devfreq device\n");
1186 mutex_unlock(&devfreq_list_lock);
1190 * devfreq_add_governor() - Add devfreq governor
1191 * @governor: the devfreq governor to be added
1193 int devfreq_add_governor(struct devfreq_governor *governor)
1195 struct devfreq_governor *g;
1196 struct devfreq *devfreq;
1200 pr_err("%s: Invalid parameters.\n", __func__);
1204 mutex_lock(&devfreq_list_lock);
1205 g = find_devfreq_governor(governor->name);
1207 pr_err("%s: governor %s already registered\n", __func__,
1213 list_add(&governor->node, &devfreq_governor_list);
1215 list_for_each_entry(devfreq, &devfreq_list, node) {
1217 struct device *dev = devfreq->dev.parent;
1219 if (!strncmp(devfreq->governor_name, governor->name,
1220 DEVFREQ_NAME_LEN)) {
1221 /* The following should never occur */
1222 if (devfreq->governor) {
1224 "%s: Governor %s already present\n",
1225 __func__, devfreq->governor->name);
1226 ret = devfreq->governor->event_handler(devfreq,
1227 DEVFREQ_GOV_STOP, NULL);
1230 "%s: Governor %s stop = %d\n",
1232 devfreq->governor->name, ret);
1236 devfreq->governor = governor;
1237 ret = devfreq->governor->event_handler(devfreq,
1238 DEVFREQ_GOV_START, NULL);
1240 dev_warn(dev, "%s: Governor %s start=%d\n",
1241 __func__, devfreq->governor->name,
1248 mutex_unlock(&devfreq_list_lock);
1252 EXPORT_SYMBOL(devfreq_add_governor);
1255 * devfreq_remove_governor() - Remove devfreq feature from a device.
1256 * @governor: the devfreq governor to be removed
1258 int devfreq_remove_governor(struct devfreq_governor *governor)
1260 struct devfreq_governor *g;
1261 struct devfreq *devfreq;
1265 pr_err("%s: Invalid parameters.\n", __func__);
1269 mutex_lock(&devfreq_list_lock);
1270 g = find_devfreq_governor(governor->name);
1272 pr_err("%s: governor %s not registered\n", __func__,
1277 list_for_each_entry(devfreq, &devfreq_list, node) {
1279 struct device *dev = devfreq->dev.parent;
1281 if (!strncmp(devfreq->governor_name, governor->name,
1282 DEVFREQ_NAME_LEN)) {
1283 /* we should have a devfreq governor! */
1284 if (!devfreq->governor) {
1285 dev_warn(dev, "%s: Governor %s NOT present\n",
1286 __func__, governor->name);
1290 ret = devfreq->governor->event_handler(devfreq,
1291 DEVFREQ_GOV_STOP, NULL);
1293 dev_warn(dev, "%s: Governor %s stop=%d\n",
1294 __func__, devfreq->governor->name,
1297 devfreq->governor = NULL;
1301 list_del(&governor->node);
1303 mutex_unlock(&devfreq_list_lock);
1307 EXPORT_SYMBOL(devfreq_remove_governor);
1309 static ssize_t name_show(struct device *dev,
1310 struct device_attribute *attr, char *buf)
1312 struct devfreq *df = to_devfreq(dev);
1313 return sprintf(buf, "%s\n", dev_name(df->dev.parent));
1315 static DEVICE_ATTR_RO(name);
1317 static ssize_t governor_show(struct device *dev,
1318 struct device_attribute *attr, char *buf)
1320 struct devfreq *df = to_devfreq(dev);
1325 return sprintf(buf, "%s\n", df->governor->name);
1328 static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
1329 const char *buf, size_t count)
1331 struct devfreq *df = to_devfreq(dev);
1333 char str_governor[DEVFREQ_NAME_LEN + 1];
1334 const struct devfreq_governor *governor, *prev_governor;
1339 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
1343 mutex_lock(&devfreq_list_lock);
1344 governor = try_then_request_governor(str_governor);
1345 if (IS_ERR(governor)) {
1346 ret = PTR_ERR(governor);
1349 if (df->governor == governor) {
1352 } else if (df->governor->immutable || governor->immutable) {
1357 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1359 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1360 __func__, df->governor->name, ret);
1364 prev_governor = df->governor;
1365 df->governor = governor;
1366 strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
1367 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1369 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1370 __func__, df->governor->name, ret);
1371 df->governor = prev_governor;
1372 strncpy(df->governor_name, prev_governor->name,
1374 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1377 "%s: reverting to Governor %s failed (%d)\n",
1378 __func__, df->governor_name, ret);
1379 df->governor = NULL;
1383 mutex_unlock(&devfreq_list_lock);
1389 static DEVICE_ATTR_RW(governor);
1391 static ssize_t available_governors_show(struct device *d,
1392 struct device_attribute *attr,
1395 struct devfreq *df = to_devfreq(d);
1401 mutex_lock(&devfreq_list_lock);
1404 * The devfreq with immutable governor (e.g., passive) shows
1405 * only own governor.
1407 if (df->governor->immutable) {
1408 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
1409 "%s ", df->governor_name);
1411 * The devfreq device shows the registered governor except for
1412 * immutable governors such as passive governor .
1415 struct devfreq_governor *governor;
1417 list_for_each_entry(governor, &devfreq_governor_list, node) {
1418 if (governor->immutable)
1420 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1421 "%s ", governor->name);
1425 mutex_unlock(&devfreq_list_lock);
1427 /* Truncate the trailing space */
1431 count += sprintf(&buf[count], "\n");
1435 static DEVICE_ATTR_RO(available_governors);
1437 static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
1441 struct devfreq *df = to_devfreq(dev);
1446 if (df->profile->get_cur_freq &&
1447 !df->profile->get_cur_freq(df->dev.parent, &freq))
1448 return sprintf(buf, "%lu\n", freq);
1450 return sprintf(buf, "%lu\n", df->previous_freq);
1452 static DEVICE_ATTR_RO(cur_freq);
1454 static ssize_t target_freq_show(struct device *dev,
1455 struct device_attribute *attr, char *buf)
1457 struct devfreq *df = to_devfreq(dev);
1459 return sprintf(buf, "%lu\n", df->previous_freq);
1461 static DEVICE_ATTR_RO(target_freq);
1463 static ssize_t polling_interval_show(struct device *dev,
1464 struct device_attribute *attr, char *buf)
1466 struct devfreq *df = to_devfreq(dev);
1471 return sprintf(buf, "%d\n", df->profile->polling_ms);
1474 static ssize_t polling_interval_store(struct device *dev,
1475 struct device_attribute *attr,
1476 const char *buf, size_t count)
1478 struct devfreq *df = to_devfreq(dev);
1485 ret = sscanf(buf, "%u", &value);
1489 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1494 static DEVICE_ATTR_RW(polling_interval);
1496 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
1497 const char *buf, size_t count)
1499 struct devfreq *df = to_devfreq(dev);
1500 unsigned long value;
1504 * Protect against theoretical sysfs writes between
1505 * device_add and dev_pm_qos_add_request
1507 if (!dev_pm_qos_request_active(&df->user_min_freq_req))
1510 ret = sscanf(buf, "%lu", &value);
1514 /* Round down to kHz for PM QoS */
1515 ret = dev_pm_qos_update_request(&df->user_min_freq_req,
1516 value / HZ_PER_KHZ);
1523 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
1526 struct devfreq *df = to_devfreq(dev);
1527 unsigned long min_freq, max_freq;
1529 mutex_lock(&df->lock);
1530 get_freq_range(df, &min_freq, &max_freq);
1531 mutex_unlock(&df->lock);
1533 return sprintf(buf, "%lu\n", min_freq);
1535 static DEVICE_ATTR_RW(min_freq);
1537 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
1538 const char *buf, size_t count)
1540 struct devfreq *df = to_devfreq(dev);
1541 unsigned long value;
1545 * Protect against theoretical sysfs writes between
1546 * device_add and dev_pm_qos_add_request
1548 if (!dev_pm_qos_request_active(&df->user_max_freq_req))
1551 ret = sscanf(buf, "%lu", &value);
1556 * PM QoS frequencies are in kHz so we need to convert. Convert by
1557 * rounding upwards so that the acceptable interval never shrinks.
1559 * For example if the user writes "666666666" to sysfs this value will
1560 * be converted to 666667 kHz and back to 666667000 Hz before an OPP
1561 * lookup, this ensures that an OPP of 666666666Hz is still accepted.
1563 * A value of zero means "no limit".
1566 value = DIV_ROUND_UP(value, HZ_PER_KHZ);
1568 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
1570 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
1577 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
1580 struct devfreq *df = to_devfreq(dev);
1581 unsigned long min_freq, max_freq;
1583 mutex_lock(&df->lock);
1584 get_freq_range(df, &min_freq, &max_freq);
1585 mutex_unlock(&df->lock);
1587 return sprintf(buf, "%lu\n", max_freq);
1589 static DEVICE_ATTR_RW(max_freq);
1591 static ssize_t available_frequencies_show(struct device *d,
1592 struct device_attribute *attr,
1595 struct devfreq *df = to_devfreq(d);
1602 mutex_lock(&df->lock);
1604 for (i = 0; i < df->profile->max_state; i++)
1605 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1606 "%lu ", df->profile->freq_table[i]);
1608 mutex_unlock(&df->lock);
1609 /* Truncate the trailing space */
1613 count += sprintf(&buf[count], "\n");
1617 static DEVICE_ATTR_RO(available_frequencies);
1619 static ssize_t trans_stat_show(struct device *dev,
1620 struct device_attribute *attr, char *buf)
1622 struct devfreq *df = to_devfreq(dev);
1625 unsigned int max_state;
1629 max_state = df->profile->max_state;
1632 return sprintf(buf, "Not Supported.\n");
1634 mutex_lock(&df->lock);
1635 if (!df->stop_polling &&
1636 devfreq_update_status(df, df->previous_freq)) {
1637 mutex_unlock(&df->lock);
1640 mutex_unlock(&df->lock);
1642 len = sprintf(buf, " From : To\n");
1643 len += sprintf(buf + len, " :");
1644 for (i = 0; i < max_state; i++)
1645 len += sprintf(buf + len, "%10lu",
1646 df->profile->freq_table[i]);
1648 len += sprintf(buf + len, " time(ms)\n");
1650 for (i = 0; i < max_state; i++) {
1651 if (df->profile->freq_table[i]
1652 == df->previous_freq) {
1653 len += sprintf(buf + len, "*");
1655 len += sprintf(buf + len, " ");
1657 len += sprintf(buf + len, "%10lu:",
1658 df->profile->freq_table[i]);
1659 for (j = 0; j < max_state; j++)
1660 len += sprintf(buf + len, "%10u",
1661 df->stats.trans_table[(i * max_state) + j]);
1663 len += sprintf(buf + len, "%10llu\n", (u64)
1664 jiffies64_to_msecs(df->stats.time_in_state[i]));
1667 len += sprintf(buf + len, "Total transition : %u\n",
1668 df->stats.total_trans);
1672 static ssize_t trans_stat_store(struct device *dev,
1673 struct device_attribute *attr,
1674 const char *buf, size_t count)
1676 struct devfreq *df = to_devfreq(dev);
1682 if (df->profile->max_state == 0)
1685 err = kstrtoint(buf, 10, &value);
1686 if (err || value != 0)
1689 mutex_lock(&df->lock);
1690 memset(df->stats.time_in_state, 0, (df->profile->max_state *
1691 sizeof(*df->stats.time_in_state)));
1692 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
1693 df->profile->max_state,
1694 df->profile->max_state));
1695 df->stats.total_trans = 0;
1696 df->stats.last_update = get_jiffies_64();
1697 mutex_unlock(&df->lock);
1701 static DEVICE_ATTR_RW(trans_stat);
1703 static ssize_t timer_show(struct device *dev,
1704 struct device_attribute *attr, char *buf)
1706 struct devfreq *df = to_devfreq(dev);
1711 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
1714 static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
1715 const char *buf, size_t count)
1717 struct devfreq *df = to_devfreq(dev);
1718 char str_timer[DEVFREQ_NAME_LEN + 1];
1722 if (!df->governor || !df->profile)
1725 ret = sscanf(buf, "%16s", str_timer);
1729 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
1730 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
1741 if (df->profile->timer == timer) {
1746 mutex_lock(&df->lock);
1747 df->profile->timer = timer;
1748 mutex_unlock(&df->lock);
1750 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1752 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1753 __func__, df->governor->name, ret);
1757 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1759 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1760 __func__, df->governor->name, ret);
1762 return ret ? ret : count;
1764 static DEVICE_ATTR_RW(timer);
1766 static struct attribute *devfreq_attrs[] = {
1767 &dev_attr_name.attr,
1768 &dev_attr_governor.attr,
1769 &dev_attr_available_governors.attr,
1770 &dev_attr_cur_freq.attr,
1771 &dev_attr_available_frequencies.attr,
1772 &dev_attr_target_freq.attr,
1773 &dev_attr_polling_interval.attr,
1774 &dev_attr_min_freq.attr,
1775 &dev_attr_max_freq.attr,
1776 &dev_attr_trans_stat.attr,
1777 &dev_attr_timer.attr,
1780 ATTRIBUTE_GROUPS(devfreq);
1783 * devfreq_summary_show() - Show the summary of the devfreq devices
1784 * @s: seq_file instance to show the summary of devfreq devices
1787 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
1788 * It helps that user can know the detailed information of the devfreq devices.
1790 * Return 0 always because it shows the information without any data change.
1792 static int devfreq_summary_show(struct seq_file *s, void *data)
1794 struct devfreq *devfreq;
1795 struct devfreq *p_devfreq = NULL;
1796 unsigned long cur_freq, min_freq, max_freq;
1797 unsigned int polling_ms;
1800 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
1809 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
1810 "------------------------------",
1811 "------------------------------",
1819 mutex_lock(&devfreq_list_lock);
1821 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
1822 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
1823 if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
1824 DEVFREQ_NAME_LEN)) {
1825 struct devfreq_passive_data *data = devfreq->data;
1828 p_devfreq = data->parent;
1834 mutex_lock(&devfreq->lock);
1835 cur_freq = devfreq->previous_freq;
1836 get_freq_range(devfreq, &min_freq, &max_freq);
1837 polling_ms = devfreq->profile->polling_ms;
1838 timer = devfreq->profile->timer;
1839 mutex_unlock(&devfreq->lock);
1842 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
1843 dev_name(&devfreq->dev),
1844 p_devfreq ? dev_name(&p_devfreq->dev) : "null",
1845 devfreq->governor_name,
1846 polling_ms ? timer_name[timer] : "null",
1853 mutex_unlock(&devfreq_list_lock);
1857 DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
1859 static int __init devfreq_init(void)
1861 devfreq_class = class_create(THIS_MODULE, "devfreq");
1862 if (IS_ERR(devfreq_class)) {
1863 pr_err("%s: couldn't create class\n", __FILE__);
1864 return PTR_ERR(devfreq_class);
1867 devfreq_wq = create_freezable_workqueue("devfreq_wq");
1869 class_destroy(devfreq_class);
1870 pr_err("%s: couldn't create workqueue\n", __FILE__);
1873 devfreq_class->dev_groups = devfreq_groups;
1875 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
1876 debugfs_create_file("devfreq_summary", 0444,
1877 devfreq_debugfs, NULL,
1878 &devfreq_summary_fops);
1882 subsys_initcall(devfreq_init);
1885 * The following are helper functions for devfreq user device drivers with
1890 * devfreq_recommended_opp() - Helper function to get proper OPP for the
1891 * freq value given to target callback.
1892 * @dev: The devfreq user device. (parent of devfreq)
1893 * @freq: The frequency given to target function
1894 * @flags: Flags handed from devfreq framework.
1896 * The callers are required to call dev_pm_opp_put() for the returned OPP after
1899 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
1900 unsigned long *freq,
1903 struct dev_pm_opp *opp;
1905 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
1906 /* The freq is an upper bound. opp should be lower */
1907 opp = dev_pm_opp_find_freq_floor(dev, freq);
1909 /* If not available, use the closest opp */
1910 if (opp == ERR_PTR(-ERANGE))
1911 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1913 /* The freq is an lower bound. opp should be higher */
1914 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1916 /* If not available, use the closest opp */
1917 if (opp == ERR_PTR(-ERANGE))
1918 opp = dev_pm_opp_find_freq_floor(dev, freq);
1923 EXPORT_SYMBOL(devfreq_recommended_opp);
1926 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
1927 * for any changes in the OPP availability
1929 * @dev: The devfreq user device. (parent of devfreq)
1930 * @devfreq: The devfreq object.
1932 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
1934 return dev_pm_opp_register_notifier(dev, &devfreq->nb);
1936 EXPORT_SYMBOL(devfreq_register_opp_notifier);
1939 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
1940 * notified for any changes in the OPP
1941 * availability changes anymore.
1942 * @dev: The devfreq user device. (parent of devfreq)
1943 * @devfreq: The devfreq object.
1945 * At exit() callback of devfreq_dev_profile, this must be included if
1946 * devfreq_recommended_opp is used.
1948 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
1950 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
1952 EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
1954 static void devm_devfreq_opp_release(struct device *dev, void *res)
1956 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
1960 * devm_devfreq_register_opp_notifier() - Resource-managed
1961 * devfreq_register_opp_notifier()
1962 * @dev: The devfreq user device. (parent of devfreq)
1963 * @devfreq: The devfreq object.
1965 int devm_devfreq_register_opp_notifier(struct device *dev,
1966 struct devfreq *devfreq)
1968 struct devfreq **ptr;
1971 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
1975 ret = devfreq_register_opp_notifier(dev, devfreq);
1982 devres_add(dev, ptr);
1986 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
1989 * devm_devfreq_unregister_opp_notifier() - Resource-managed
1990 * devfreq_unregister_opp_notifier()
1991 * @dev: The devfreq user device. (parent of devfreq)
1992 * @devfreq: The devfreq object.
1994 void devm_devfreq_unregister_opp_notifier(struct device *dev,
1995 struct devfreq *devfreq)
1997 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
1998 devm_devfreq_dev_match, devfreq));
2000 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
2003 * devfreq_register_notifier() - Register a driver with devfreq
2004 * @devfreq: The devfreq object.
2005 * @nb: The notifier block to register.
2006 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2008 int devfreq_register_notifier(struct devfreq *devfreq,
2009 struct notifier_block *nb,
2018 case DEVFREQ_TRANSITION_NOTIFIER:
2019 ret = srcu_notifier_chain_register(
2020 &devfreq->transition_notifier_list, nb);
2028 EXPORT_SYMBOL(devfreq_register_notifier);
2031 * devfreq_unregister_notifier() - Unregister a driver with devfreq
2032 * @devfreq: The devfreq object.
2033 * @nb: The notifier block to be unregistered.
2034 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2036 int devfreq_unregister_notifier(struct devfreq *devfreq,
2037 struct notifier_block *nb,
2046 case DEVFREQ_TRANSITION_NOTIFIER:
2047 ret = srcu_notifier_chain_unregister(
2048 &devfreq->transition_notifier_list, nb);
2056 EXPORT_SYMBOL(devfreq_unregister_notifier);
2058 struct devfreq_notifier_devres {
2059 struct devfreq *devfreq;
2060 struct notifier_block *nb;
2064 static void devm_devfreq_notifier_release(struct device *dev, void *res)
2066 struct devfreq_notifier_devres *this = res;
2068 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
2072 * devm_devfreq_register_notifier()
2073 * - Resource-managed devfreq_register_notifier()
2074 * @dev: The devfreq user device. (parent of devfreq)
2075 * @devfreq: The devfreq object.
2076 * @nb: The notifier block to be unregistered.
2077 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2079 int devm_devfreq_register_notifier(struct device *dev,
2080 struct devfreq *devfreq,
2081 struct notifier_block *nb,
2084 struct devfreq_notifier_devres *ptr;
2087 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
2092 ret = devfreq_register_notifier(devfreq, nb, list);
2098 ptr->devfreq = devfreq;
2101 devres_add(dev, ptr);
2105 EXPORT_SYMBOL(devm_devfreq_register_notifier);
2108 * devm_devfreq_unregister_notifier()
2109 * - Resource-managed devfreq_unregister_notifier()
2110 * @dev: The devfreq user device. (parent of devfreq)
2111 * @devfreq: The devfreq object.
2112 * @nb: The notifier block to be unregistered.
2113 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2115 void devm_devfreq_unregister_notifier(struct device *dev,
2116 struct devfreq *devfreq,
2117 struct notifier_block *nb,
2120 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
2121 devm_devfreq_dev_match, devfreq));
2123 EXPORT_SYMBOL(devm_devfreq_unregister_notifier);