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/devfreq_cooling.h>
15 #include <linux/errno.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/export.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>
29 #include <linux/pm_qos.h>
30 #include <linux/units.h>
33 #define CREATE_TRACE_POINTS
34 #include <trace/events/devfreq.h>
36 #define IS_SUPPORTED_FLAG(f, name) ((f & DEVFREQ_GOV_FLAG_##name) ? true : false)
37 #define IS_SUPPORTED_ATTR(f, name) ((f & DEVFREQ_GOV_ATTR_##name) ? true : false)
39 static struct class *devfreq_class;
40 static struct dentry *devfreq_debugfs;
43 * devfreq core provides delayed work based load monitoring helper
44 * functions. Governors can use these or can implement their own
45 * monitoring mechanism.
47 static struct workqueue_struct *devfreq_wq;
49 /* The list of all device-devfreq governors */
50 static LIST_HEAD(devfreq_governor_list);
51 /* The list of all device-devfreq */
52 static LIST_HEAD(devfreq_list);
53 static DEFINE_MUTEX(devfreq_list_lock);
55 static const char timer_name[][DEVFREQ_NAME_LEN] = {
56 [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" },
57 [DEVFREQ_TIMER_DELAYED] = { "delayed" },
61 * find_device_devfreq() - find devfreq struct using device pointer
62 * @dev: device pointer used to lookup device devfreq.
64 * Search the list of device devfreqs and return the matched device's
65 * devfreq info. devfreq_list_lock should be held by the caller.
67 static struct devfreq *find_device_devfreq(struct device *dev)
69 struct devfreq *tmp_devfreq;
71 lockdep_assert_held(&devfreq_list_lock);
73 if (IS_ERR_OR_NULL(dev)) {
74 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
75 return ERR_PTR(-EINVAL);
78 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
79 if (tmp_devfreq->dev.parent == dev)
83 return ERR_PTR(-ENODEV);
86 static unsigned long find_available_min_freq(struct devfreq *devfreq)
88 struct dev_pm_opp *opp;
89 unsigned long min_freq = 0;
91 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq);
100 static unsigned long find_available_max_freq(struct devfreq *devfreq)
102 struct dev_pm_opp *opp;
103 unsigned long max_freq = ULONG_MAX;
105 opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq);
115 * get_freq_range() - Get the current freq range
116 * @devfreq: the devfreq instance
117 * @min_freq: the min frequency
118 * @max_freq: the max frequency
120 * This takes into consideration all constraints.
122 static void get_freq_range(struct devfreq *devfreq,
123 unsigned long *min_freq,
124 unsigned long *max_freq)
126 unsigned long *freq_table = devfreq->profile->freq_table;
127 s32 qos_min_freq, qos_max_freq;
129 lockdep_assert_held(&devfreq->lock);
132 * Initialize minimum/maximum frequency from freq table.
133 * The devfreq drivers can initialize this in either ascending or
134 * descending order and devfreq core supports both.
136 if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) {
137 *min_freq = freq_table[0];
138 *max_freq = freq_table[devfreq->profile->max_state - 1];
140 *min_freq = freq_table[devfreq->profile->max_state - 1];
141 *max_freq = freq_table[0];
144 /* Apply constraints from PM QoS */
145 qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,
146 DEV_PM_QOS_MIN_FREQUENCY);
147 qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,
148 DEV_PM_QOS_MAX_FREQUENCY);
149 *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);
150 if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)
151 *max_freq = min(*max_freq,
152 (unsigned long)HZ_PER_KHZ * qos_max_freq);
154 /* Apply constraints from OPP interface */
155 *min_freq = max(*min_freq, devfreq->scaling_min_freq);
156 *max_freq = min(*max_freq, devfreq->scaling_max_freq);
158 if (*min_freq > *max_freq)
159 *min_freq = *max_freq;
163 * devfreq_get_freq_level() - Lookup freq_table for the frequency
164 * @devfreq: the devfreq instance
165 * @freq: the target frequency
167 static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
171 for (lev = 0; lev < devfreq->profile->max_state; lev++)
172 if (freq == devfreq->profile->freq_table[lev])
178 static int set_freq_table(struct devfreq *devfreq)
180 struct devfreq_dev_profile *profile = devfreq->profile;
181 struct dev_pm_opp *opp;
185 /* Initialize the freq_table from OPP table */
186 count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
190 profile->max_state = count;
191 profile->freq_table = devm_kcalloc(devfreq->dev.parent,
193 sizeof(*profile->freq_table),
195 if (!profile->freq_table) {
196 profile->max_state = 0;
200 for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
201 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
203 devm_kfree(devfreq->dev.parent, profile->freq_table);
204 profile->max_state = 0;
208 profile->freq_table[i] = freq;
215 * devfreq_update_status() - Update statistics of devfreq behavior
216 * @devfreq: the devfreq instance
217 * @freq: the update target frequency
219 int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
221 int lev, prev_lev, ret = 0;
224 lockdep_assert_held(&devfreq->lock);
225 cur_time = get_jiffies_64();
227 /* Immediately exit if previous_freq is not initialized yet. */
228 if (!devfreq->previous_freq)
231 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
237 devfreq->stats.time_in_state[prev_lev] +=
238 cur_time - devfreq->stats.last_update;
240 lev = devfreq_get_freq_level(devfreq, freq);
246 if (lev != prev_lev) {
247 devfreq->stats.trans_table[
248 (prev_lev * devfreq->profile->max_state) + lev]++;
249 devfreq->stats.total_trans++;
253 devfreq->stats.last_update = cur_time;
256 EXPORT_SYMBOL(devfreq_update_status);
259 * find_devfreq_governor() - find devfreq governor from name
260 * @name: name of the governor
262 * Search the list of devfreq governors and return the matched
263 * governor's pointer. devfreq_list_lock should be held by the caller.
265 static struct devfreq_governor *find_devfreq_governor(const char *name)
267 struct devfreq_governor *tmp_governor;
269 lockdep_assert_held(&devfreq_list_lock);
271 if (IS_ERR_OR_NULL(name)) {
272 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
273 return ERR_PTR(-EINVAL);
276 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
277 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
281 return ERR_PTR(-ENODEV);
285 * try_then_request_governor() - Try to find the governor and request the
286 * module if is not found.
287 * @name: name of the governor
289 * Search the list of devfreq governors and request the module and try again
290 * if is not found. This can happen when both drivers (the governor driver
291 * and the driver that call devfreq_add_device) are built as modules.
292 * devfreq_list_lock should be held by the caller. Returns the matched
293 * governor's pointer or an error pointer.
295 static struct devfreq_governor *try_then_request_governor(const char *name)
297 struct devfreq_governor *governor;
300 lockdep_assert_held(&devfreq_list_lock);
302 if (IS_ERR_OR_NULL(name)) {
303 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
304 return ERR_PTR(-EINVAL);
307 governor = find_devfreq_governor(name);
308 if (IS_ERR(governor)) {
309 mutex_unlock(&devfreq_list_lock);
311 if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND,
313 err = request_module("governor_%s", "simpleondemand");
315 err = request_module("governor_%s", name);
316 /* Restore previous state before return */
317 mutex_lock(&devfreq_list_lock);
319 return (err < 0) ? ERR_PTR(err) : ERR_PTR(-EINVAL);
321 governor = find_devfreq_governor(name);
327 static int devfreq_notify_transition(struct devfreq *devfreq,
328 struct devfreq_freqs *freqs, unsigned int state)
334 case DEVFREQ_PRECHANGE:
335 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
336 DEVFREQ_PRECHANGE, freqs);
339 case DEVFREQ_POSTCHANGE:
340 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
341 DEVFREQ_POSTCHANGE, freqs);
350 static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
353 struct devfreq_freqs freqs;
354 unsigned long cur_freq;
357 if (devfreq->profile->get_cur_freq)
358 devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
360 cur_freq = devfreq->previous_freq;
362 freqs.old = cur_freq;
363 freqs.new = new_freq;
364 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
366 err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
368 freqs.new = cur_freq;
369 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
374 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
375 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
376 * change order of between devfreq device and passive devfreq device.
378 if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
379 trace_devfreq_frequency(devfreq, new_freq, cur_freq);
381 freqs.new = new_freq;
382 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
384 if (devfreq_update_status(devfreq, new_freq))
385 dev_err(&devfreq->dev,
386 "Couldn't update frequency transition information.\n");
388 devfreq->previous_freq = new_freq;
390 if (devfreq->suspend_freq)
391 devfreq->resume_freq = new_freq;
397 * devfreq_update_target() - Reevaluate the device and configure frequency
398 * on the final stage.
399 * @devfreq: the devfreq instance.
400 * @freq: the new frequency of parent device. This argument
401 * is only used for devfreq device using passive governor.
403 * Note: Lock devfreq->lock before calling devfreq_update_target. This function
404 * should be only used by both update_devfreq() and devfreq governors.
406 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
408 unsigned long min_freq, max_freq;
412 lockdep_assert_held(&devfreq->lock);
414 if (!devfreq->governor)
417 /* Reevaluate the proper frequency */
418 err = devfreq->governor->get_target_freq(devfreq, &freq);
421 get_freq_range(devfreq, &min_freq, &max_freq);
423 if (freq < min_freq) {
425 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
427 if (freq > max_freq) {
429 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
432 return devfreq_set_target(devfreq, freq, flags);
434 EXPORT_SYMBOL(devfreq_update_target);
436 /* Load monitoring helper functions for governors use */
439 * update_devfreq() - Reevaluate the device and configure frequency.
440 * @devfreq: the devfreq instance.
442 * Note: Lock devfreq->lock before calling update_devfreq
443 * This function is exported for governors.
445 int update_devfreq(struct devfreq *devfreq)
447 return devfreq_update_target(devfreq, 0L);
449 EXPORT_SYMBOL(update_devfreq);
452 * devfreq_monitor() - Periodically poll devfreq objects.
453 * @work: the work struct used to run devfreq_monitor periodically.
456 static void devfreq_monitor(struct work_struct *work)
459 struct devfreq *devfreq = container_of(work,
460 struct devfreq, work.work);
462 mutex_lock(&devfreq->lock);
463 err = update_devfreq(devfreq);
465 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
467 queue_delayed_work(devfreq_wq, &devfreq->work,
468 msecs_to_jiffies(devfreq->profile->polling_ms));
469 mutex_unlock(&devfreq->lock);
471 trace_devfreq_monitor(devfreq);
475 * devfreq_monitor_start() - Start load monitoring of devfreq instance
476 * @devfreq: the devfreq instance.
478 * Helper function for starting devfreq device load monitoring. By
479 * default delayed work based monitoring is supported. Function
480 * to be called from governor in response to DEVFREQ_GOV_START
481 * event when device is added to devfreq framework.
483 void devfreq_monitor_start(struct devfreq *devfreq)
485 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
488 switch (devfreq->profile->timer) {
489 case DEVFREQ_TIMER_DEFERRABLE:
490 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
492 case DEVFREQ_TIMER_DELAYED:
493 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
499 if (devfreq->profile->polling_ms)
500 queue_delayed_work(devfreq_wq, &devfreq->work,
501 msecs_to_jiffies(devfreq->profile->polling_ms));
503 EXPORT_SYMBOL(devfreq_monitor_start);
506 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
507 * @devfreq: the devfreq instance.
509 * Helper function to stop devfreq device load monitoring. Function
510 * to be called from governor in response to DEVFREQ_GOV_STOP
511 * event when device is removed from devfreq framework.
513 void devfreq_monitor_stop(struct devfreq *devfreq)
515 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
518 cancel_delayed_work_sync(&devfreq->work);
520 EXPORT_SYMBOL(devfreq_monitor_stop);
523 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
524 * @devfreq: the devfreq instance.
526 * Helper function to suspend devfreq device load monitoring. Function
527 * to be called from governor in response to DEVFREQ_GOV_SUSPEND
528 * event or when polling interval is set to zero.
530 * Note: Though this function is same as devfreq_monitor_stop(),
531 * intentionally kept separate to provide hooks for collecting
532 * transition statistics.
534 void devfreq_monitor_suspend(struct devfreq *devfreq)
536 mutex_lock(&devfreq->lock);
537 if (devfreq->stop_polling) {
538 mutex_unlock(&devfreq->lock);
542 devfreq_update_status(devfreq, devfreq->previous_freq);
543 devfreq->stop_polling = true;
544 mutex_unlock(&devfreq->lock);
546 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
549 cancel_delayed_work_sync(&devfreq->work);
551 EXPORT_SYMBOL(devfreq_monitor_suspend);
554 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
555 * @devfreq: the devfreq instance.
557 * Helper function to resume devfreq device load monitoring. Function
558 * to be called from governor in response to DEVFREQ_GOV_RESUME
559 * event or when polling interval is set to non-zero.
561 void devfreq_monitor_resume(struct devfreq *devfreq)
565 mutex_lock(&devfreq->lock);
567 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
570 if (!devfreq->stop_polling)
573 if (!delayed_work_pending(&devfreq->work) &&
574 devfreq->profile->polling_ms)
575 queue_delayed_work(devfreq_wq, &devfreq->work,
576 msecs_to_jiffies(devfreq->profile->polling_ms));
579 devfreq->stats.last_update = get_jiffies_64();
580 devfreq->stop_polling = false;
582 if (devfreq->profile->get_cur_freq &&
583 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
584 devfreq->previous_freq = freq;
587 mutex_unlock(&devfreq->lock);
589 EXPORT_SYMBOL(devfreq_monitor_resume);
592 * devfreq_update_interval() - Update device devfreq monitoring interval
593 * @devfreq: the devfreq instance.
594 * @delay: new polling interval to be set.
596 * Helper function to set new load monitoring polling interval. Function
597 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.
599 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)
601 unsigned int cur_delay = devfreq->profile->polling_ms;
602 unsigned int new_delay = *delay;
604 mutex_lock(&devfreq->lock);
605 devfreq->profile->polling_ms = new_delay;
607 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
610 if (devfreq->stop_polling)
613 /* if new delay is zero, stop polling */
615 mutex_unlock(&devfreq->lock);
616 cancel_delayed_work_sync(&devfreq->work);
620 /* if current delay is zero, start polling with new delay */
622 queue_delayed_work(devfreq_wq, &devfreq->work,
623 msecs_to_jiffies(devfreq->profile->polling_ms));
627 /* if current delay is greater than new delay, restart polling */
628 if (cur_delay > new_delay) {
629 mutex_unlock(&devfreq->lock);
630 cancel_delayed_work_sync(&devfreq->work);
631 mutex_lock(&devfreq->lock);
632 if (!devfreq->stop_polling)
633 queue_delayed_work(devfreq_wq, &devfreq->work,
634 msecs_to_jiffies(devfreq->profile->polling_ms));
637 mutex_unlock(&devfreq->lock);
639 EXPORT_SYMBOL(devfreq_update_interval);
642 * devfreq_notifier_call() - Notify that the device frequency requirements
643 * has been changed out of devfreq framework.
644 * @nb: the notifier_block (supposed to be devfreq->nb)
648 * Called by a notifier that uses devfreq->nb.
650 static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
653 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
656 mutex_lock(&devfreq->lock);
658 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
659 if (!devfreq->scaling_min_freq)
662 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
663 if (!devfreq->scaling_max_freq) {
664 devfreq->scaling_max_freq = ULONG_MAX;
668 err = update_devfreq(devfreq);
671 mutex_unlock(&devfreq->lock);
673 dev_err(devfreq->dev.parent,
674 "failed to update frequency from OPP notifier (%d)\n",
681 * qos_notifier_call() - Common handler for QoS constraints.
682 * @devfreq: the devfreq instance.
684 static int qos_notifier_call(struct devfreq *devfreq)
688 mutex_lock(&devfreq->lock);
689 err = update_devfreq(devfreq);
690 mutex_unlock(&devfreq->lock);
692 dev_err(devfreq->dev.parent,
693 "failed to update frequency from PM QoS (%d)\n",
700 * qos_min_notifier_call() - Callback for QoS min_freq changes.
701 * @nb: Should be devfreq->nb_min
703 static int qos_min_notifier_call(struct notifier_block *nb,
704 unsigned long val, void *ptr)
706 return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
710 * qos_max_notifier_call() - Callback for QoS max_freq changes.
711 * @nb: Should be devfreq->nb_max
713 static int qos_max_notifier_call(struct notifier_block *nb,
714 unsigned long val, void *ptr)
716 return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
720 * devfreq_dev_release() - Callback for struct device to release the device.
721 * @dev: the devfreq device
723 * Remove devfreq from the list and release its resources.
725 static void devfreq_dev_release(struct device *dev)
727 struct devfreq *devfreq = to_devfreq(dev);
730 mutex_lock(&devfreq_list_lock);
731 list_del(&devfreq->node);
732 mutex_unlock(&devfreq_list_lock);
734 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
735 DEV_PM_QOS_MAX_FREQUENCY);
736 if (err && err != -ENOENT)
737 dev_warn(dev->parent,
738 "Failed to remove max_freq notifier: %d\n", err);
739 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
740 DEV_PM_QOS_MIN_FREQUENCY);
741 if (err && err != -ENOENT)
742 dev_warn(dev->parent,
743 "Failed to remove min_freq notifier: %d\n", err);
745 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
746 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
748 dev_warn(dev->parent,
749 "Failed to remove max_freq request: %d\n", err);
751 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
752 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
754 dev_warn(dev->parent,
755 "Failed to remove min_freq request: %d\n", err);
758 if (devfreq->profile->exit)
759 devfreq->profile->exit(devfreq->dev.parent);
761 if (devfreq->opp_table)
762 dev_pm_opp_put_opp_table(devfreq->opp_table);
764 mutex_destroy(&devfreq->lock);
768 static void create_sysfs_files(struct devfreq *devfreq,
769 const struct devfreq_governor *gov);
770 static void remove_sysfs_files(struct devfreq *devfreq,
771 const struct devfreq_governor *gov);
774 * devfreq_add_device() - Add devfreq feature to the device
775 * @dev: the device to add devfreq feature.
776 * @profile: device-specific profile to run devfreq.
777 * @governor_name: name of the policy to choose frequency.
778 * @data: devfreq driver pass to governors, governor should not change it.
780 struct devfreq *devfreq_add_device(struct device *dev,
781 struct devfreq_dev_profile *profile,
782 const char *governor_name,
785 struct devfreq *devfreq;
786 struct devfreq_governor *governor;
789 if (!dev || !profile || !governor_name) {
790 dev_err(dev, "%s: Invalid parameters.\n", __func__);
791 return ERR_PTR(-EINVAL);
794 mutex_lock(&devfreq_list_lock);
795 devfreq = find_device_devfreq(dev);
796 mutex_unlock(&devfreq_list_lock);
797 if (!IS_ERR(devfreq)) {
798 dev_err(dev, "%s: devfreq device already exists!\n",
804 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
810 mutex_init(&devfreq->lock);
811 mutex_lock(&devfreq->lock);
812 devfreq->dev.parent = dev;
813 devfreq->dev.class = devfreq_class;
814 devfreq->dev.release = devfreq_dev_release;
815 INIT_LIST_HEAD(&devfreq->node);
816 devfreq->profile = profile;
817 devfreq->previous_freq = profile->initial_freq;
818 devfreq->last_status.current_frequency = profile->initial_freq;
819 devfreq->data = data;
820 devfreq->nb.notifier_call = devfreq_notifier_call;
822 if (devfreq->profile->timer < 0
823 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {
824 mutex_unlock(&devfreq->lock);
829 if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
830 mutex_unlock(&devfreq->lock);
831 err = set_freq_table(devfreq);
834 mutex_lock(&devfreq->lock);
837 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
838 if (!devfreq->scaling_min_freq) {
839 mutex_unlock(&devfreq->lock);
844 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
845 if (!devfreq->scaling_max_freq) {
846 mutex_unlock(&devfreq->lock);
851 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
852 devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
853 if (IS_ERR(devfreq->opp_table))
854 devfreq->opp_table = NULL;
856 atomic_set(&devfreq->suspend_count, 0);
858 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
859 err = device_register(&devfreq->dev);
861 mutex_unlock(&devfreq->lock);
862 put_device(&devfreq->dev);
866 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
867 array3_size(sizeof(unsigned int),
868 devfreq->profile->max_state,
869 devfreq->profile->max_state),
871 if (!devfreq->stats.trans_table) {
872 mutex_unlock(&devfreq->lock);
877 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
878 devfreq->profile->max_state,
879 sizeof(*devfreq->stats.time_in_state),
881 if (!devfreq->stats.time_in_state) {
882 mutex_unlock(&devfreq->lock);
887 devfreq->stats.total_trans = 0;
888 devfreq->stats.last_update = get_jiffies_64();
890 srcu_init_notifier_head(&devfreq->transition_notifier_list);
892 mutex_unlock(&devfreq->lock);
894 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
895 DEV_PM_QOS_MIN_FREQUENCY, 0);
898 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
899 DEV_PM_QOS_MAX_FREQUENCY,
900 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
904 devfreq->nb_min.notifier_call = qos_min_notifier_call;
905 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min,
906 DEV_PM_QOS_MIN_FREQUENCY);
910 devfreq->nb_max.notifier_call = qos_max_notifier_call;
911 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max,
912 DEV_PM_QOS_MAX_FREQUENCY);
916 mutex_lock(&devfreq_list_lock);
918 governor = try_then_request_governor(governor_name);
919 if (IS_ERR(governor)) {
920 dev_err(dev, "%s: Unable to find governor for the device\n",
922 err = PTR_ERR(governor);
926 devfreq->governor = governor;
927 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
930 dev_err(dev, "%s: Unable to start governor for the device\n",
934 create_sysfs_files(devfreq, devfreq->governor);
936 list_add(&devfreq->node, &devfreq_list);
938 mutex_unlock(&devfreq_list_lock);
940 if (devfreq->profile->is_cooling_device) {
941 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
942 if (IS_ERR(devfreq->cdev))
943 devfreq->cdev = NULL;
949 mutex_unlock(&devfreq_list_lock);
951 devfreq_remove_device(devfreq);
958 EXPORT_SYMBOL(devfreq_add_device);
961 * devfreq_remove_device() - Remove devfreq feature from a device.
962 * @devfreq: the devfreq instance to be removed
964 * The opposite of devfreq_add_device().
966 int devfreq_remove_device(struct devfreq *devfreq)
971 devfreq_cooling_unregister(devfreq->cdev);
973 if (devfreq->governor) {
974 devfreq->governor->event_handler(devfreq,
975 DEVFREQ_GOV_STOP, NULL);
976 remove_sysfs_files(devfreq, devfreq->governor);
979 device_unregister(&devfreq->dev);
983 EXPORT_SYMBOL(devfreq_remove_device);
985 static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
987 struct devfreq **r = res;
989 if (WARN_ON(!r || !*r))
995 static void devm_devfreq_dev_release(struct device *dev, void *res)
997 devfreq_remove_device(*(struct devfreq **)res);
1001 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
1002 * @dev: the device to add devfreq feature.
1003 * @profile: device-specific profile to run devfreq.
1004 * @governor_name: name of the policy to choose frequency.
1005 * @data: devfreq driver pass to governors, governor should not change it.
1007 * This function manages automatically the memory of devfreq device using device
1008 * resource management and simplify the free operation for memory of devfreq
1011 struct devfreq *devm_devfreq_add_device(struct device *dev,
1012 struct devfreq_dev_profile *profile,
1013 const char *governor_name,
1016 struct devfreq **ptr, *devfreq;
1018 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
1020 return ERR_PTR(-ENOMEM);
1022 devfreq = devfreq_add_device(dev, profile, governor_name, data);
1023 if (IS_ERR(devfreq)) {
1029 devres_add(dev, ptr);
1033 EXPORT_SYMBOL(devm_devfreq_add_device);
1037 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree
1038 * @node - pointer to device_node
1040 * return the instance of devfreq device
1042 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1044 struct devfreq *devfreq;
1047 return ERR_PTR(-EINVAL);
1049 mutex_lock(&devfreq_list_lock);
1050 list_for_each_entry(devfreq, &devfreq_list, node) {
1051 if (devfreq->dev.parent
1052 && devfreq->dev.parent->of_node == node) {
1053 mutex_unlock(&devfreq_list_lock);
1057 mutex_unlock(&devfreq_list_lock);
1059 return ERR_PTR(-ENODEV);
1063 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
1064 * @dev - instance to the given device
1065 * @phandle_name - name of property holding a phandle value
1066 * @index - index into list of devfreq
1068 * return the instance of devfreq device
1070 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1071 const char *phandle_name, int index)
1073 struct device_node *node;
1074 struct devfreq *devfreq;
1076 if (!dev || !phandle_name)
1077 return ERR_PTR(-EINVAL);
1080 return ERR_PTR(-EINVAL);
1082 node = of_parse_phandle(dev->of_node, phandle_name, index);
1084 return ERR_PTR(-ENODEV);
1086 devfreq = devfreq_get_devfreq_by_node(node);
1093 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1095 return ERR_PTR(-ENODEV);
1098 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1099 const char *phandle_name, int index)
1101 return ERR_PTR(-ENODEV);
1103 #endif /* CONFIG_OF */
1104 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
1105 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
1108 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
1109 * @dev: the device from which to remove devfreq feature.
1110 * @devfreq: the devfreq instance to be removed
1112 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
1114 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
1115 devm_devfreq_dev_match, devfreq));
1117 EXPORT_SYMBOL(devm_devfreq_remove_device);
1120 * devfreq_suspend_device() - Suspend devfreq of a device.
1121 * @devfreq: the devfreq instance to be suspended
1123 * This function is intended to be called by the pm callbacks
1124 * (e.g., runtime_suspend, suspend) of the device driver that
1125 * holds the devfreq.
1127 int devfreq_suspend_device(struct devfreq *devfreq)
1134 if (atomic_inc_return(&devfreq->suspend_count) > 1)
1137 if (devfreq->governor) {
1138 ret = devfreq->governor->event_handler(devfreq,
1139 DEVFREQ_GOV_SUSPEND, NULL);
1144 if (devfreq->suspend_freq) {
1145 mutex_lock(&devfreq->lock);
1146 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
1147 mutex_unlock(&devfreq->lock);
1154 EXPORT_SYMBOL(devfreq_suspend_device);
1157 * devfreq_resume_device() - Resume devfreq of a device.
1158 * @devfreq: the devfreq instance to be resumed
1160 * This function is intended to be called by the pm callbacks
1161 * (e.g., runtime_resume, resume) of the device driver that
1162 * holds the devfreq.
1164 int devfreq_resume_device(struct devfreq *devfreq)
1171 if (atomic_dec_return(&devfreq->suspend_count) >= 1)
1174 if (devfreq->resume_freq) {
1175 mutex_lock(&devfreq->lock);
1176 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
1177 mutex_unlock(&devfreq->lock);
1182 if (devfreq->governor) {
1183 ret = devfreq->governor->event_handler(devfreq,
1184 DEVFREQ_GOV_RESUME, NULL);
1191 EXPORT_SYMBOL(devfreq_resume_device);
1194 * devfreq_suspend() - Suspend devfreq governors and devices
1196 * Called during system wide Suspend/Hibernate cycles for suspending governors
1197 * and devices preserving the state for resume. On some platforms the devfreq
1198 * device must have precise state (frequency) after resume in order to provide
1199 * fully operating setup.
1201 void devfreq_suspend(void)
1203 struct devfreq *devfreq;
1206 mutex_lock(&devfreq_list_lock);
1207 list_for_each_entry(devfreq, &devfreq_list, node) {
1208 ret = devfreq_suspend_device(devfreq);
1210 dev_err(&devfreq->dev,
1211 "failed to suspend devfreq device\n");
1213 mutex_unlock(&devfreq_list_lock);
1217 * devfreq_resume() - Resume devfreq governors and devices
1219 * Called during system wide Suspend/Hibernate cycle for resuming governors and
1220 * devices that are suspended with devfreq_suspend().
1222 void devfreq_resume(void)
1224 struct devfreq *devfreq;
1227 mutex_lock(&devfreq_list_lock);
1228 list_for_each_entry(devfreq, &devfreq_list, node) {
1229 ret = devfreq_resume_device(devfreq);
1231 dev_warn(&devfreq->dev,
1232 "failed to resume devfreq device\n");
1234 mutex_unlock(&devfreq_list_lock);
1238 * devfreq_add_governor() - Add devfreq governor
1239 * @governor: the devfreq governor to be added
1241 int devfreq_add_governor(struct devfreq_governor *governor)
1243 struct devfreq_governor *g;
1244 struct devfreq *devfreq;
1248 pr_err("%s: Invalid parameters.\n", __func__);
1252 mutex_lock(&devfreq_list_lock);
1253 g = find_devfreq_governor(governor->name);
1255 pr_err("%s: governor %s already registered\n", __func__,
1261 list_add(&governor->node, &devfreq_governor_list);
1263 list_for_each_entry(devfreq, &devfreq_list, node) {
1265 struct device *dev = devfreq->dev.parent;
1267 if (!strncmp(devfreq->governor->name, governor->name,
1268 DEVFREQ_NAME_LEN)) {
1269 /* The following should never occur */
1270 if (devfreq->governor) {
1272 "%s: Governor %s already present\n",
1273 __func__, devfreq->governor->name);
1274 ret = devfreq->governor->event_handler(devfreq,
1275 DEVFREQ_GOV_STOP, NULL);
1278 "%s: Governor %s stop = %d\n",
1280 devfreq->governor->name, ret);
1284 devfreq->governor = governor;
1285 ret = devfreq->governor->event_handler(devfreq,
1286 DEVFREQ_GOV_START, NULL);
1288 dev_warn(dev, "%s: Governor %s start=%d\n",
1289 __func__, devfreq->governor->name,
1296 mutex_unlock(&devfreq_list_lock);
1300 EXPORT_SYMBOL(devfreq_add_governor);
1303 * devfreq_remove_governor() - Remove devfreq feature from a device.
1304 * @governor: the devfreq governor to be removed
1306 int devfreq_remove_governor(struct devfreq_governor *governor)
1308 struct devfreq_governor *g;
1309 struct devfreq *devfreq;
1313 pr_err("%s: Invalid parameters.\n", __func__);
1317 mutex_lock(&devfreq_list_lock);
1318 g = find_devfreq_governor(governor->name);
1320 pr_err("%s: governor %s not registered\n", __func__,
1325 list_for_each_entry(devfreq, &devfreq_list, node) {
1327 struct device *dev = devfreq->dev.parent;
1329 if (!strncmp(devfreq->governor->name, governor->name,
1330 DEVFREQ_NAME_LEN)) {
1331 /* we should have a devfreq governor! */
1332 if (!devfreq->governor) {
1333 dev_warn(dev, "%s: Governor %s NOT present\n",
1334 __func__, governor->name);
1338 ret = devfreq->governor->event_handler(devfreq,
1339 DEVFREQ_GOV_STOP, NULL);
1341 dev_warn(dev, "%s: Governor %s stop=%d\n",
1342 __func__, devfreq->governor->name,
1345 devfreq->governor = NULL;
1349 list_del(&governor->node);
1351 mutex_unlock(&devfreq_list_lock);
1355 EXPORT_SYMBOL(devfreq_remove_governor);
1357 static ssize_t name_show(struct device *dev,
1358 struct device_attribute *attr, char *buf)
1360 struct devfreq *df = to_devfreq(dev);
1361 return sprintf(buf, "%s\n", dev_name(df->dev.parent));
1363 static DEVICE_ATTR_RO(name);
1365 static ssize_t governor_show(struct device *dev,
1366 struct device_attribute *attr, char *buf)
1368 struct devfreq *df = to_devfreq(dev);
1373 return sprintf(buf, "%s\n", df->governor->name);
1376 static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
1377 const char *buf, size_t count)
1379 struct devfreq *df = to_devfreq(dev);
1381 char str_governor[DEVFREQ_NAME_LEN + 1];
1382 const struct devfreq_governor *governor, *prev_governor;
1387 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
1391 mutex_lock(&devfreq_list_lock);
1392 governor = try_then_request_governor(str_governor);
1393 if (IS_ERR(governor)) {
1394 ret = PTR_ERR(governor);
1397 if (df->governor == governor) {
1400 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
1401 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
1407 * Stop the current governor and remove the specific sysfs files
1408 * which depend on current governor.
1410 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1412 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1413 __func__, df->governor->name, ret);
1416 remove_sysfs_files(df, df->governor);
1419 * Start the new governor and create the specific sysfs files
1420 * which depend on the new governor.
1422 prev_governor = df->governor;
1423 df->governor = governor;
1424 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1426 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1427 __func__, df->governor->name, ret);
1429 /* Restore previous governor */
1430 df->governor = prev_governor;
1431 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1434 "%s: reverting to Governor %s failed (%d)\n",
1435 __func__, prev_governor->name, ret);
1436 df->governor = NULL;
1442 * Create the sysfs files for the new governor. But if failed to start
1443 * the new governor, restore the sysfs files of previous governor.
1445 create_sysfs_files(df, df->governor);
1448 mutex_unlock(&devfreq_list_lock);
1454 static DEVICE_ATTR_RW(governor);
1456 static ssize_t available_governors_show(struct device *d,
1457 struct device_attribute *attr,
1460 struct devfreq *df = to_devfreq(d);
1466 mutex_lock(&devfreq_list_lock);
1469 * The devfreq with immutable governor (e.g., passive) shows
1470 * only own governor.
1472 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
1473 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
1474 "%s ", df->governor->name);
1476 * The devfreq device shows the registered governor except for
1477 * immutable governors such as passive governor .
1480 struct devfreq_governor *governor;
1482 list_for_each_entry(governor, &devfreq_governor_list, node) {
1483 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
1485 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1486 "%s ", governor->name);
1490 mutex_unlock(&devfreq_list_lock);
1492 /* Truncate the trailing space */
1496 count += sprintf(&buf[count], "\n");
1500 static DEVICE_ATTR_RO(available_governors);
1502 static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
1506 struct devfreq *df = to_devfreq(dev);
1511 if (df->profile->get_cur_freq &&
1512 !df->profile->get_cur_freq(df->dev.parent, &freq))
1513 return sprintf(buf, "%lu\n", freq);
1515 return sprintf(buf, "%lu\n", df->previous_freq);
1517 static DEVICE_ATTR_RO(cur_freq);
1519 static ssize_t target_freq_show(struct device *dev,
1520 struct device_attribute *attr, char *buf)
1522 struct devfreq *df = to_devfreq(dev);
1524 return sprintf(buf, "%lu\n", df->previous_freq);
1526 static DEVICE_ATTR_RO(target_freq);
1528 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
1529 const char *buf, size_t count)
1531 struct devfreq *df = to_devfreq(dev);
1532 unsigned long value;
1536 * Protect against theoretical sysfs writes between
1537 * device_add and dev_pm_qos_add_request
1539 if (!dev_pm_qos_request_active(&df->user_min_freq_req))
1542 ret = sscanf(buf, "%lu", &value);
1546 /* Round down to kHz for PM QoS */
1547 ret = dev_pm_qos_update_request(&df->user_min_freq_req,
1548 value / HZ_PER_KHZ);
1555 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
1558 struct devfreq *df = to_devfreq(dev);
1559 unsigned long min_freq, max_freq;
1561 mutex_lock(&df->lock);
1562 get_freq_range(df, &min_freq, &max_freq);
1563 mutex_unlock(&df->lock);
1565 return sprintf(buf, "%lu\n", min_freq);
1567 static DEVICE_ATTR_RW(min_freq);
1569 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
1570 const char *buf, size_t count)
1572 struct devfreq *df = to_devfreq(dev);
1573 unsigned long value;
1577 * Protect against theoretical sysfs writes between
1578 * device_add and dev_pm_qos_add_request
1580 if (!dev_pm_qos_request_active(&df->user_max_freq_req))
1583 ret = sscanf(buf, "%lu", &value);
1588 * PM QoS frequencies are in kHz so we need to convert. Convert by
1589 * rounding upwards so that the acceptable interval never shrinks.
1591 * For example if the user writes "666666666" to sysfs this value will
1592 * be converted to 666667 kHz and back to 666667000 Hz before an OPP
1593 * lookup, this ensures that an OPP of 666666666Hz is still accepted.
1595 * A value of zero means "no limit".
1598 value = DIV_ROUND_UP(value, HZ_PER_KHZ);
1600 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
1602 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
1609 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
1612 struct devfreq *df = to_devfreq(dev);
1613 unsigned long min_freq, max_freq;
1615 mutex_lock(&df->lock);
1616 get_freq_range(df, &min_freq, &max_freq);
1617 mutex_unlock(&df->lock);
1619 return sprintf(buf, "%lu\n", max_freq);
1621 static DEVICE_ATTR_RW(max_freq);
1623 static ssize_t available_frequencies_show(struct device *d,
1624 struct device_attribute *attr,
1627 struct devfreq *df = to_devfreq(d);
1634 mutex_lock(&df->lock);
1636 for (i = 0; i < df->profile->max_state; i++)
1637 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1638 "%lu ", df->profile->freq_table[i]);
1640 mutex_unlock(&df->lock);
1641 /* Truncate the trailing space */
1645 count += sprintf(&buf[count], "\n");
1649 static DEVICE_ATTR_RO(available_frequencies);
1651 static ssize_t trans_stat_show(struct device *dev,
1652 struct device_attribute *attr, char *buf)
1654 struct devfreq *df = to_devfreq(dev);
1657 unsigned int max_state;
1661 max_state = df->profile->max_state;
1664 return sprintf(buf, "Not Supported.\n");
1666 mutex_lock(&df->lock);
1667 if (!df->stop_polling &&
1668 devfreq_update_status(df, df->previous_freq)) {
1669 mutex_unlock(&df->lock);
1672 mutex_unlock(&df->lock);
1674 len = sprintf(buf, " From : To\n");
1675 len += sprintf(buf + len, " :");
1676 for (i = 0; i < max_state; i++)
1677 len += sprintf(buf + len, "%10lu",
1678 df->profile->freq_table[i]);
1680 len += sprintf(buf + len, " time(ms)\n");
1682 for (i = 0; i < max_state; i++) {
1683 if (df->profile->freq_table[i]
1684 == df->previous_freq) {
1685 len += sprintf(buf + len, "*");
1687 len += sprintf(buf + len, " ");
1689 len += sprintf(buf + len, "%10lu:",
1690 df->profile->freq_table[i]);
1691 for (j = 0; j < max_state; j++)
1692 len += sprintf(buf + len, "%10u",
1693 df->stats.trans_table[(i * max_state) + j]);
1695 len += sprintf(buf + len, "%10llu\n", (u64)
1696 jiffies64_to_msecs(df->stats.time_in_state[i]));
1699 len += sprintf(buf + len, "Total transition : %u\n",
1700 df->stats.total_trans);
1704 static ssize_t trans_stat_store(struct device *dev,
1705 struct device_attribute *attr,
1706 const char *buf, size_t count)
1708 struct devfreq *df = to_devfreq(dev);
1714 if (df->profile->max_state == 0)
1717 err = kstrtoint(buf, 10, &value);
1718 if (err || value != 0)
1721 mutex_lock(&df->lock);
1722 memset(df->stats.time_in_state, 0, (df->profile->max_state *
1723 sizeof(*df->stats.time_in_state)));
1724 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
1725 df->profile->max_state,
1726 df->profile->max_state));
1727 df->stats.total_trans = 0;
1728 df->stats.last_update = get_jiffies_64();
1729 mutex_unlock(&df->lock);
1733 static DEVICE_ATTR_RW(trans_stat);
1735 static struct attribute *devfreq_attrs[] = {
1736 &dev_attr_name.attr,
1737 &dev_attr_governor.attr,
1738 &dev_attr_available_governors.attr,
1739 &dev_attr_cur_freq.attr,
1740 &dev_attr_available_frequencies.attr,
1741 &dev_attr_target_freq.attr,
1742 &dev_attr_min_freq.attr,
1743 &dev_attr_max_freq.attr,
1744 &dev_attr_trans_stat.attr,
1747 ATTRIBUTE_GROUPS(devfreq);
1749 static ssize_t polling_interval_show(struct device *dev,
1750 struct device_attribute *attr, char *buf)
1752 struct devfreq *df = to_devfreq(dev);
1757 return sprintf(buf, "%d\n", df->profile->polling_ms);
1760 static ssize_t polling_interval_store(struct device *dev,
1761 struct device_attribute *attr,
1762 const char *buf, size_t count)
1764 struct devfreq *df = to_devfreq(dev);
1771 ret = sscanf(buf, "%u", &value);
1775 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1780 static DEVICE_ATTR_RW(polling_interval);
1782 static ssize_t timer_show(struct device *dev,
1783 struct device_attribute *attr, char *buf)
1785 struct devfreq *df = to_devfreq(dev);
1790 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
1793 static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
1794 const char *buf, size_t count)
1796 struct devfreq *df = to_devfreq(dev);
1797 char str_timer[DEVFREQ_NAME_LEN + 1];
1801 if (!df->governor || !df->profile)
1804 ret = sscanf(buf, "%16s", str_timer);
1808 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
1809 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
1820 if (df->profile->timer == timer) {
1825 mutex_lock(&df->lock);
1826 df->profile->timer = timer;
1827 mutex_unlock(&df->lock);
1829 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1831 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1832 __func__, df->governor->name, ret);
1836 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1838 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1839 __func__, df->governor->name, ret);
1841 return ret ? ret : count;
1843 static DEVICE_ATTR_RW(timer);
1845 #define CREATE_SYSFS_FILE(df, name) \
1848 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \
1850 dev_warn(&df->dev, \
1851 "Unable to create attr(%s)\n", "##name"); \
1855 /* Create the specific sysfs files which depend on each governor. */
1856 static void create_sysfs_files(struct devfreq *devfreq,
1857 const struct devfreq_governor *gov)
1859 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1860 CREATE_SYSFS_FILE(devfreq, polling_interval);
1861 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1862 CREATE_SYSFS_FILE(devfreq, timer);
1865 /* Remove the specific sysfs files which depend on each governor. */
1866 static void remove_sysfs_files(struct devfreq *devfreq,
1867 const struct devfreq_governor *gov)
1869 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1870 sysfs_remove_file(&devfreq->dev.kobj,
1871 &dev_attr_polling_interval.attr);
1872 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1873 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);
1877 * devfreq_summary_show() - Show the summary of the devfreq devices
1878 * @s: seq_file instance to show the summary of devfreq devices
1881 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
1882 * It helps that user can know the detailed information of the devfreq devices.
1884 * Return 0 always because it shows the information without any data change.
1886 static int devfreq_summary_show(struct seq_file *s, void *data)
1888 struct devfreq *devfreq;
1889 struct devfreq *p_devfreq = NULL;
1890 unsigned long cur_freq, min_freq, max_freq;
1891 unsigned int polling_ms;
1894 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
1903 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
1904 "------------------------------",
1905 "------------------------------",
1913 mutex_lock(&devfreq_list_lock);
1915 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
1916 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
1917 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
1918 DEVFREQ_NAME_LEN)) {
1919 struct devfreq_passive_data *data = devfreq->data;
1922 p_devfreq = data->parent;
1928 mutex_lock(&devfreq->lock);
1929 cur_freq = devfreq->previous_freq;
1930 get_freq_range(devfreq, &min_freq, &max_freq);
1931 timer = devfreq->profile->timer;
1933 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
1934 polling_ms = devfreq->profile->polling_ms;
1937 mutex_unlock(&devfreq->lock);
1940 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
1941 dev_name(&devfreq->dev),
1942 p_devfreq ? dev_name(&p_devfreq->dev) : "null",
1943 devfreq->governor->name,
1944 polling_ms ? timer_name[timer] : "null",
1951 mutex_unlock(&devfreq_list_lock);
1955 DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
1957 static int __init devfreq_init(void)
1959 devfreq_class = class_create(THIS_MODULE, "devfreq");
1960 if (IS_ERR(devfreq_class)) {
1961 pr_err("%s: couldn't create class\n", __FILE__);
1962 return PTR_ERR(devfreq_class);
1965 devfreq_wq = create_freezable_workqueue("devfreq_wq");
1967 class_destroy(devfreq_class);
1968 pr_err("%s: couldn't create workqueue\n", __FILE__);
1971 devfreq_class->dev_groups = devfreq_groups;
1973 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
1974 debugfs_create_file("devfreq_summary", 0444,
1975 devfreq_debugfs, NULL,
1976 &devfreq_summary_fops);
1980 subsys_initcall(devfreq_init);
1983 * The following are helper functions for devfreq user device drivers with
1988 * devfreq_recommended_opp() - Helper function to get proper OPP for the
1989 * freq value given to target callback.
1990 * @dev: The devfreq user device. (parent of devfreq)
1991 * @freq: The frequency given to target function
1992 * @flags: Flags handed from devfreq framework.
1994 * The callers are required to call dev_pm_opp_put() for the returned OPP after
1997 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
1998 unsigned long *freq,
2001 struct dev_pm_opp *opp;
2003 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
2004 /* The freq is an upper bound. opp should be lower */
2005 opp = dev_pm_opp_find_freq_floor(dev, freq);
2007 /* If not available, use the closest opp */
2008 if (opp == ERR_PTR(-ERANGE))
2009 opp = dev_pm_opp_find_freq_ceil(dev, freq);
2011 /* The freq is an lower bound. opp should be higher */
2012 opp = dev_pm_opp_find_freq_ceil(dev, freq);
2014 /* If not available, use the closest opp */
2015 if (opp == ERR_PTR(-ERANGE))
2016 opp = dev_pm_opp_find_freq_floor(dev, freq);
2021 EXPORT_SYMBOL(devfreq_recommended_opp);
2024 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
2025 * for any changes in the OPP availability
2027 * @dev: The devfreq user device. (parent of devfreq)
2028 * @devfreq: The devfreq object.
2030 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
2032 return dev_pm_opp_register_notifier(dev, &devfreq->nb);
2034 EXPORT_SYMBOL(devfreq_register_opp_notifier);
2037 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
2038 * notified for any changes in the OPP
2039 * availability changes anymore.
2040 * @dev: The devfreq user device. (parent of devfreq)
2041 * @devfreq: The devfreq object.
2043 * At exit() callback of devfreq_dev_profile, this must be included if
2044 * devfreq_recommended_opp is used.
2046 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
2048 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
2050 EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
2052 static void devm_devfreq_opp_release(struct device *dev, void *res)
2054 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
2058 * devm_devfreq_register_opp_notifier() - Resource-managed
2059 * devfreq_register_opp_notifier()
2060 * @dev: The devfreq user device. (parent of devfreq)
2061 * @devfreq: The devfreq object.
2063 int devm_devfreq_register_opp_notifier(struct device *dev,
2064 struct devfreq *devfreq)
2066 struct devfreq **ptr;
2069 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
2073 ret = devfreq_register_opp_notifier(dev, devfreq);
2080 devres_add(dev, ptr);
2084 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
2087 * devm_devfreq_unregister_opp_notifier() - Resource-managed
2088 * devfreq_unregister_opp_notifier()
2089 * @dev: The devfreq user device. (parent of devfreq)
2090 * @devfreq: The devfreq object.
2092 void devm_devfreq_unregister_opp_notifier(struct device *dev,
2093 struct devfreq *devfreq)
2095 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
2096 devm_devfreq_dev_match, devfreq));
2098 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
2101 * devfreq_register_notifier() - Register a driver with devfreq
2102 * @devfreq: The devfreq object.
2103 * @nb: The notifier block to register.
2104 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2106 int devfreq_register_notifier(struct devfreq *devfreq,
2107 struct notifier_block *nb,
2116 case DEVFREQ_TRANSITION_NOTIFIER:
2117 ret = srcu_notifier_chain_register(
2118 &devfreq->transition_notifier_list, nb);
2126 EXPORT_SYMBOL(devfreq_register_notifier);
2129 * devfreq_unregister_notifier() - Unregister a driver with devfreq
2130 * @devfreq: The devfreq object.
2131 * @nb: The notifier block to be unregistered.
2132 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2134 int devfreq_unregister_notifier(struct devfreq *devfreq,
2135 struct notifier_block *nb,
2144 case DEVFREQ_TRANSITION_NOTIFIER:
2145 ret = srcu_notifier_chain_unregister(
2146 &devfreq->transition_notifier_list, nb);
2154 EXPORT_SYMBOL(devfreq_unregister_notifier);
2156 struct devfreq_notifier_devres {
2157 struct devfreq *devfreq;
2158 struct notifier_block *nb;
2162 static void devm_devfreq_notifier_release(struct device *dev, void *res)
2164 struct devfreq_notifier_devres *this = res;
2166 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
2170 * devm_devfreq_register_notifier()
2171 * - Resource-managed devfreq_register_notifier()
2172 * @dev: The devfreq user device. (parent of devfreq)
2173 * @devfreq: The devfreq object.
2174 * @nb: The notifier block to be unregistered.
2175 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2177 int devm_devfreq_register_notifier(struct device *dev,
2178 struct devfreq *devfreq,
2179 struct notifier_block *nb,
2182 struct devfreq_notifier_devres *ptr;
2185 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
2190 ret = devfreq_register_notifier(devfreq, nb, list);
2196 ptr->devfreq = devfreq;
2199 devres_add(dev, ptr);
2203 EXPORT_SYMBOL(devm_devfreq_register_notifier);
2206 * devm_devfreq_unregister_notifier()
2207 * - Resource-managed devfreq_unregister_notifier()
2208 * @dev: The devfreq user device. (parent of devfreq)
2209 * @devfreq: The devfreq object.
2210 * @nb: The notifier block to be unregistered.
2211 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2213 void devm_devfreq_unregister_notifier(struct device *dev,
2214 struct devfreq *devfreq,
2215 struct notifier_block *nb,
2218 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
2219 devm_devfreq_dev_match, devfreq));
2221 EXPORT_SYMBOL(devm_devfreq_unregister_notifier);