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_indexed(devfreq->dev.parent, &min_freq, 0);
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_indexed(devfreq->dev.parent, &max_freq, 0);
115 * devfreq_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 void devfreq_get_freq_range(struct devfreq *devfreq,
123 unsigned long *min_freq,
124 unsigned long *max_freq)
126 unsigned long *freq_table = devfreq->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->max_state - 1]) {
137 *min_freq = freq_table[0];
138 *max_freq = freq_table[devfreq->max_state - 1];
140 *min_freq = freq_table[devfreq->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;
161 EXPORT_SYMBOL(devfreq_get_freq_range);
164 * devfreq_get_freq_level() - Lookup freq_table for the frequency
165 * @devfreq: the devfreq instance
166 * @freq: the target frequency
168 static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
172 for (lev = 0; lev < devfreq->max_state; lev++)
173 if (freq == devfreq->freq_table[lev])
179 static int set_freq_table(struct devfreq *devfreq)
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 devfreq->max_state = count;
191 devfreq->freq_table = devm_kcalloc(devfreq->dev.parent,
193 sizeof(*devfreq->freq_table),
195 if (!devfreq->freq_table)
198 for (i = 0, freq = 0; i < devfreq->max_state; i++, freq++) {
199 opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &freq, 0);
201 devm_kfree(devfreq->dev.parent, devfreq->freq_table);
205 devfreq->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->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);
371 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
372 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
373 * change order of between devfreq device and passive devfreq device.
375 if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
376 trace_devfreq_frequency(devfreq, new_freq, cur_freq);
378 freqs.new = new_freq;
379 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
381 if (devfreq_update_status(devfreq, new_freq))
382 dev_warn(&devfreq->dev,
383 "Couldn't update frequency transition information.\n");
385 devfreq->previous_freq = new_freq;
387 if (devfreq->suspend_freq)
388 devfreq->resume_freq = new_freq;
394 * devfreq_update_target() - Reevaluate the device and configure frequency
395 * on the final stage.
396 * @devfreq: the devfreq instance.
397 * @freq: the new frequency of parent device. This argument
398 * is only used for devfreq device using passive governor.
400 * Note: Lock devfreq->lock before calling devfreq_update_target. This function
401 * should be only used by both update_devfreq() and devfreq governors.
403 int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
405 unsigned long min_freq, max_freq;
409 lockdep_assert_held(&devfreq->lock);
411 if (!devfreq->governor)
414 /* Reevaluate the proper frequency */
415 err = devfreq->governor->get_target_freq(devfreq, &freq);
418 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
420 if (freq < min_freq) {
422 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
424 if (freq > max_freq) {
426 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
429 return devfreq_set_target(devfreq, freq, flags);
431 EXPORT_SYMBOL(devfreq_update_target);
433 /* Load monitoring helper functions for governors use */
436 * update_devfreq() - Reevaluate the device and configure frequency.
437 * @devfreq: the devfreq instance.
439 * Note: Lock devfreq->lock before calling update_devfreq
440 * This function is exported for governors.
442 int update_devfreq(struct devfreq *devfreq)
444 return devfreq_update_target(devfreq, 0L);
446 EXPORT_SYMBOL(update_devfreq);
449 * devfreq_monitor() - Periodically poll devfreq objects.
450 * @work: the work struct used to run devfreq_monitor periodically.
453 static void devfreq_monitor(struct work_struct *work)
456 struct devfreq *devfreq = container_of(work,
457 struct devfreq, work.work);
459 mutex_lock(&devfreq->lock);
460 err = update_devfreq(devfreq);
462 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
464 if (devfreq->stop_polling)
467 queue_delayed_work(devfreq_wq, &devfreq->work,
468 msecs_to_jiffies(devfreq->profile->polling_ms));
471 mutex_unlock(&devfreq->lock);
472 trace_devfreq_monitor(devfreq);
476 * devfreq_monitor_start() - Start load monitoring of devfreq instance
477 * @devfreq: the devfreq instance.
479 * Helper function for starting devfreq device load monitoring. By default,
480 * deferrable timer is used for load monitoring. But the users can change this
481 * behavior using the "timer" type in devfreq_dev_profile. This function will be
482 * called by devfreq governor in response to the DEVFREQ_GOV_START event
483 * generated while adding a device to the devfreq framework.
485 void devfreq_monitor_start(struct devfreq *devfreq)
487 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
490 mutex_lock(&devfreq->lock);
491 if (delayed_work_pending(&devfreq->work))
494 switch (devfreq->profile->timer) {
495 case DEVFREQ_TIMER_DEFERRABLE:
496 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
498 case DEVFREQ_TIMER_DELAYED:
499 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
505 if (devfreq->profile->polling_ms)
506 queue_delayed_work(devfreq_wq, &devfreq->work,
507 msecs_to_jiffies(devfreq->profile->polling_ms));
510 devfreq->stop_polling = false;
511 mutex_unlock(&devfreq->lock);
513 EXPORT_SYMBOL(devfreq_monitor_start);
516 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
517 * @devfreq: the devfreq instance.
519 * Helper function to stop devfreq device load monitoring. Function
520 * to be called from governor in response to DEVFREQ_GOV_STOP
521 * event when device is removed from devfreq framework.
523 void devfreq_monitor_stop(struct devfreq *devfreq)
525 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
528 mutex_lock(&devfreq->lock);
529 if (devfreq->stop_polling) {
530 mutex_unlock(&devfreq->lock);
534 devfreq->stop_polling = true;
535 mutex_unlock(&devfreq->lock);
536 cancel_delayed_work_sync(&devfreq->work);
538 EXPORT_SYMBOL(devfreq_monitor_stop);
541 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
542 * @devfreq: the devfreq instance.
544 * Helper function to suspend devfreq device load monitoring. Function
545 * to be called from governor in response to DEVFREQ_GOV_SUSPEND
546 * event or when polling interval is set to zero.
548 * Note: Though this function is same as devfreq_monitor_stop(),
549 * intentionally kept separate to provide hooks for collecting
550 * transition statistics.
552 void devfreq_monitor_suspend(struct devfreq *devfreq)
554 mutex_lock(&devfreq->lock);
555 if (devfreq->stop_polling) {
556 mutex_unlock(&devfreq->lock);
560 devfreq_update_status(devfreq, devfreq->previous_freq);
561 devfreq->stop_polling = true;
562 mutex_unlock(&devfreq->lock);
564 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
567 cancel_delayed_work_sync(&devfreq->work);
569 EXPORT_SYMBOL(devfreq_monitor_suspend);
572 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
573 * @devfreq: the devfreq instance.
575 * Helper function to resume devfreq device load monitoring. Function
576 * to be called from governor in response to DEVFREQ_GOV_RESUME
577 * event or when polling interval is set to non-zero.
579 void devfreq_monitor_resume(struct devfreq *devfreq)
583 mutex_lock(&devfreq->lock);
585 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
588 if (!devfreq->stop_polling)
591 if (!delayed_work_pending(&devfreq->work) &&
592 devfreq->profile->polling_ms)
593 queue_delayed_work(devfreq_wq, &devfreq->work,
594 msecs_to_jiffies(devfreq->profile->polling_ms));
597 devfreq->stats.last_update = get_jiffies_64();
598 devfreq->stop_polling = false;
600 if (devfreq->profile->get_cur_freq &&
601 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
602 devfreq->previous_freq = freq;
605 mutex_unlock(&devfreq->lock);
607 EXPORT_SYMBOL(devfreq_monitor_resume);
610 * devfreq_update_interval() - Update device devfreq monitoring interval
611 * @devfreq: the devfreq instance.
612 * @delay: new polling interval to be set.
614 * Helper function to set new load monitoring polling interval. Function
615 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.
617 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)
619 unsigned int cur_delay = devfreq->profile->polling_ms;
620 unsigned int new_delay = *delay;
622 mutex_lock(&devfreq->lock);
623 devfreq->profile->polling_ms = new_delay;
625 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
628 if (devfreq->stop_polling)
631 /* if new delay is zero, stop polling */
633 mutex_unlock(&devfreq->lock);
634 cancel_delayed_work_sync(&devfreq->work);
638 /* if current delay is zero, start polling with new delay */
640 queue_delayed_work(devfreq_wq, &devfreq->work,
641 msecs_to_jiffies(devfreq->profile->polling_ms));
645 /* if current delay is greater than new delay, restart polling */
646 if (cur_delay > new_delay) {
647 mutex_unlock(&devfreq->lock);
648 cancel_delayed_work_sync(&devfreq->work);
649 mutex_lock(&devfreq->lock);
650 if (!devfreq->stop_polling)
651 queue_delayed_work(devfreq_wq, &devfreq->work,
652 msecs_to_jiffies(devfreq->profile->polling_ms));
655 mutex_unlock(&devfreq->lock);
657 EXPORT_SYMBOL(devfreq_update_interval);
660 * devfreq_notifier_call() - Notify that the device frequency requirements
661 * has been changed out of devfreq framework.
662 * @nb: the notifier_block (supposed to be devfreq->nb)
666 * Called by a notifier that uses devfreq->nb.
668 static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
671 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
674 mutex_lock(&devfreq->lock);
676 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
677 if (!devfreq->scaling_min_freq)
680 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
681 if (!devfreq->scaling_max_freq) {
682 devfreq->scaling_max_freq = ULONG_MAX;
686 err = update_devfreq(devfreq);
689 mutex_unlock(&devfreq->lock);
691 dev_err(devfreq->dev.parent,
692 "failed to update frequency from OPP notifier (%d)\n",
699 * qos_notifier_call() - Common handler for QoS constraints.
700 * @devfreq: the devfreq instance.
702 static int qos_notifier_call(struct devfreq *devfreq)
706 mutex_lock(&devfreq->lock);
707 err = update_devfreq(devfreq);
708 mutex_unlock(&devfreq->lock);
710 dev_err(devfreq->dev.parent,
711 "failed to update frequency from PM QoS (%d)\n",
718 * qos_min_notifier_call() - Callback for QoS min_freq changes.
719 * @nb: Should be devfreq->nb_min
723 static int qos_min_notifier_call(struct notifier_block *nb,
724 unsigned long val, void *ptr)
726 return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
730 * qos_max_notifier_call() - Callback for QoS max_freq changes.
731 * @nb: Should be devfreq->nb_max
735 static int qos_max_notifier_call(struct notifier_block *nb,
736 unsigned long val, void *ptr)
738 return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
742 * devfreq_dev_release() - Callback for struct device to release the device.
743 * @dev: the devfreq device
745 * Remove devfreq from the list and release its resources.
747 static void devfreq_dev_release(struct device *dev)
749 struct devfreq *devfreq = to_devfreq(dev);
752 mutex_lock(&devfreq_list_lock);
753 list_del(&devfreq->node);
754 mutex_unlock(&devfreq_list_lock);
756 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
757 DEV_PM_QOS_MAX_FREQUENCY);
758 if (err && err != -ENOENT)
759 dev_warn(dev->parent,
760 "Failed to remove max_freq notifier: %d\n", err);
761 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
762 DEV_PM_QOS_MIN_FREQUENCY);
763 if (err && err != -ENOENT)
764 dev_warn(dev->parent,
765 "Failed to remove min_freq notifier: %d\n", err);
767 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
768 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
770 dev_warn(dev->parent,
771 "Failed to remove max_freq request: %d\n", err);
773 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
774 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
776 dev_warn(dev->parent,
777 "Failed to remove min_freq request: %d\n", err);
780 if (devfreq->profile->exit)
781 devfreq->profile->exit(devfreq->dev.parent);
783 if (devfreq->opp_table)
784 dev_pm_opp_put_opp_table(devfreq->opp_table);
786 mutex_destroy(&devfreq->lock);
787 srcu_cleanup_notifier_head(&devfreq->transition_notifier_list);
791 static void create_sysfs_files(struct devfreq *devfreq,
792 const struct devfreq_governor *gov);
793 static void remove_sysfs_files(struct devfreq *devfreq,
794 const struct devfreq_governor *gov);
797 * devfreq_add_device() - Add devfreq feature to the device
798 * @dev: the device to add devfreq feature.
799 * @profile: device-specific profile to run devfreq.
800 * @governor_name: name of the policy to choose frequency.
801 * @data: devfreq driver pass to governors, governor should not change it.
803 struct devfreq *devfreq_add_device(struct device *dev,
804 struct devfreq_dev_profile *profile,
805 const char *governor_name,
808 struct devfreq *devfreq;
809 struct devfreq_governor *governor;
810 unsigned long min_freq, max_freq;
813 if (!dev || !profile || !governor_name) {
814 dev_err(dev, "%s: Invalid parameters.\n", __func__);
815 return ERR_PTR(-EINVAL);
818 mutex_lock(&devfreq_list_lock);
819 devfreq = find_device_devfreq(dev);
820 mutex_unlock(&devfreq_list_lock);
821 if (!IS_ERR(devfreq)) {
822 dev_err(dev, "%s: devfreq device already exists!\n",
828 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
834 mutex_init(&devfreq->lock);
835 mutex_lock(&devfreq->lock);
836 devfreq->dev.parent = dev;
837 devfreq->dev.class = devfreq_class;
838 devfreq->dev.release = devfreq_dev_release;
839 INIT_LIST_HEAD(&devfreq->node);
840 devfreq->profile = profile;
841 devfreq->previous_freq = profile->initial_freq;
842 devfreq->last_status.current_frequency = profile->initial_freq;
843 devfreq->data = data;
844 devfreq->nb.notifier_call = devfreq_notifier_call;
846 if (devfreq->profile->timer < 0
847 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {
848 mutex_unlock(&devfreq->lock);
853 if (!devfreq->profile->max_state || !devfreq->profile->freq_table) {
854 mutex_unlock(&devfreq->lock);
855 err = set_freq_table(devfreq);
858 mutex_lock(&devfreq->lock);
860 devfreq->freq_table = devfreq->profile->freq_table;
861 devfreq->max_state = devfreq->profile->max_state;
864 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
865 if (!devfreq->scaling_min_freq) {
866 mutex_unlock(&devfreq->lock);
871 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
872 if (!devfreq->scaling_max_freq) {
873 mutex_unlock(&devfreq->lock);
878 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
880 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
881 devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
882 if (IS_ERR(devfreq->opp_table))
883 devfreq->opp_table = NULL;
885 atomic_set(&devfreq->suspend_count, 0);
887 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
888 err = device_register(&devfreq->dev);
890 mutex_unlock(&devfreq->lock);
891 put_device(&devfreq->dev);
895 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
896 array3_size(sizeof(unsigned int),
900 if (!devfreq->stats.trans_table) {
901 mutex_unlock(&devfreq->lock);
906 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
908 sizeof(*devfreq->stats.time_in_state),
910 if (!devfreq->stats.time_in_state) {
911 mutex_unlock(&devfreq->lock);
916 devfreq->stats.total_trans = 0;
917 devfreq->stats.last_update = get_jiffies_64();
919 srcu_init_notifier_head(&devfreq->transition_notifier_list);
921 mutex_unlock(&devfreq->lock);
923 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
924 DEV_PM_QOS_MIN_FREQUENCY, 0);
927 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
928 DEV_PM_QOS_MAX_FREQUENCY,
929 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
933 devfreq->nb_min.notifier_call = qos_min_notifier_call;
934 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min,
935 DEV_PM_QOS_MIN_FREQUENCY);
939 devfreq->nb_max.notifier_call = qos_max_notifier_call;
940 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max,
941 DEV_PM_QOS_MAX_FREQUENCY);
945 mutex_lock(&devfreq_list_lock);
947 governor = try_then_request_governor(governor_name);
948 if (IS_ERR(governor)) {
949 dev_err(dev, "%s: Unable to find governor for the device\n",
951 err = PTR_ERR(governor);
955 devfreq->governor = governor;
956 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
959 dev_err_probe(dev, err,
960 "%s: Unable to start governor for the device\n",
964 create_sysfs_files(devfreq, devfreq->governor);
966 list_add(&devfreq->node, &devfreq_list);
968 mutex_unlock(&devfreq_list_lock);
970 if (devfreq->profile->is_cooling_device) {
971 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
972 if (IS_ERR(devfreq->cdev))
973 devfreq->cdev = NULL;
979 mutex_unlock(&devfreq_list_lock);
981 devfreq_remove_device(devfreq);
988 EXPORT_SYMBOL(devfreq_add_device);
991 * devfreq_remove_device() - Remove devfreq feature from a device.
992 * @devfreq: the devfreq instance to be removed
994 * The opposite of devfreq_add_device().
996 int devfreq_remove_device(struct devfreq *devfreq)
1001 devfreq_cooling_unregister(devfreq->cdev);
1003 if (devfreq->governor) {
1004 devfreq->governor->event_handler(devfreq,
1005 DEVFREQ_GOV_STOP, NULL);
1006 remove_sysfs_files(devfreq, devfreq->governor);
1009 device_unregister(&devfreq->dev);
1013 EXPORT_SYMBOL(devfreq_remove_device);
1015 static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
1017 struct devfreq **r = res;
1019 if (WARN_ON(!r || !*r))
1025 static void devm_devfreq_dev_release(struct device *dev, void *res)
1027 devfreq_remove_device(*(struct devfreq **)res);
1031 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
1032 * @dev: the device to add devfreq feature.
1033 * @profile: device-specific profile to run devfreq.
1034 * @governor_name: name of the policy to choose frequency.
1035 * @data: devfreq driver pass to governors, governor should not change it.
1037 * This function manages automatically the memory of devfreq device using device
1038 * resource management and simplify the free operation for memory of devfreq
1041 struct devfreq *devm_devfreq_add_device(struct device *dev,
1042 struct devfreq_dev_profile *profile,
1043 const char *governor_name,
1046 struct devfreq **ptr, *devfreq;
1048 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
1050 return ERR_PTR(-ENOMEM);
1052 devfreq = devfreq_add_device(dev, profile, governor_name, data);
1053 if (IS_ERR(devfreq)) {
1059 devres_add(dev, ptr);
1063 EXPORT_SYMBOL(devm_devfreq_add_device);
1067 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree
1068 * @node - pointer to device_node
1070 * return the instance of devfreq device
1072 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1074 struct devfreq *devfreq;
1077 return ERR_PTR(-EINVAL);
1079 mutex_lock(&devfreq_list_lock);
1080 list_for_each_entry(devfreq, &devfreq_list, node) {
1081 if (devfreq->dev.parent
1082 && device_match_of_node(devfreq->dev.parent, node)) {
1083 mutex_unlock(&devfreq_list_lock);
1087 mutex_unlock(&devfreq_list_lock);
1089 return ERR_PTR(-ENODEV);
1093 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
1094 * @dev - instance to the given device
1095 * @phandle_name - name of property holding a phandle value
1096 * @index - index into list of devfreq
1098 * return the instance of devfreq device
1100 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1101 const char *phandle_name, int index)
1103 struct device_node *node;
1104 struct devfreq *devfreq;
1106 if (!dev || !phandle_name)
1107 return ERR_PTR(-EINVAL);
1110 return ERR_PTR(-EINVAL);
1112 node = of_parse_phandle(dev->of_node, phandle_name, index);
1114 return ERR_PTR(-ENODEV);
1116 devfreq = devfreq_get_devfreq_by_node(node);
1123 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1125 return ERR_PTR(-ENODEV);
1128 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1129 const char *phandle_name, int index)
1131 return ERR_PTR(-ENODEV);
1133 #endif /* CONFIG_OF */
1134 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
1135 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
1138 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
1139 * @dev: the device from which to remove devfreq feature.
1140 * @devfreq: the devfreq instance to be removed
1142 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
1144 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
1145 devm_devfreq_dev_match, devfreq));
1147 EXPORT_SYMBOL(devm_devfreq_remove_device);
1150 * devfreq_suspend_device() - Suspend devfreq of a device.
1151 * @devfreq: the devfreq instance to be suspended
1153 * This function is intended to be called by the pm callbacks
1154 * (e.g., runtime_suspend, suspend) of the device driver that
1155 * holds the devfreq.
1157 int devfreq_suspend_device(struct devfreq *devfreq)
1164 if (atomic_inc_return(&devfreq->suspend_count) > 1)
1167 if (devfreq->governor) {
1168 ret = devfreq->governor->event_handler(devfreq,
1169 DEVFREQ_GOV_SUSPEND, NULL);
1174 if (devfreq->suspend_freq) {
1175 mutex_lock(&devfreq->lock);
1176 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
1177 mutex_unlock(&devfreq->lock);
1184 EXPORT_SYMBOL(devfreq_suspend_device);
1187 * devfreq_resume_device() - Resume devfreq of a device.
1188 * @devfreq: the devfreq instance to be resumed
1190 * This function is intended to be called by the pm callbacks
1191 * (e.g., runtime_resume, resume) of the device driver that
1192 * holds the devfreq.
1194 int devfreq_resume_device(struct devfreq *devfreq)
1201 if (atomic_dec_return(&devfreq->suspend_count) >= 1)
1204 if (devfreq->resume_freq) {
1205 mutex_lock(&devfreq->lock);
1206 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
1207 mutex_unlock(&devfreq->lock);
1212 if (devfreq->governor) {
1213 ret = devfreq->governor->event_handler(devfreq,
1214 DEVFREQ_GOV_RESUME, NULL);
1221 EXPORT_SYMBOL(devfreq_resume_device);
1224 * devfreq_suspend() - Suspend devfreq governors and devices
1226 * Called during system wide Suspend/Hibernate cycles for suspending governors
1227 * and devices preserving the state for resume. On some platforms the devfreq
1228 * device must have precise state (frequency) after resume in order to provide
1229 * fully operating setup.
1231 void devfreq_suspend(void)
1233 struct devfreq *devfreq;
1236 mutex_lock(&devfreq_list_lock);
1237 list_for_each_entry(devfreq, &devfreq_list, node) {
1238 ret = devfreq_suspend_device(devfreq);
1240 dev_err(&devfreq->dev,
1241 "failed to suspend devfreq device\n");
1243 mutex_unlock(&devfreq_list_lock);
1247 * devfreq_resume() - Resume devfreq governors and devices
1249 * Called during system wide Suspend/Hibernate cycle for resuming governors and
1250 * devices that are suspended with devfreq_suspend().
1252 void devfreq_resume(void)
1254 struct devfreq *devfreq;
1257 mutex_lock(&devfreq_list_lock);
1258 list_for_each_entry(devfreq, &devfreq_list, node) {
1259 ret = devfreq_resume_device(devfreq);
1261 dev_warn(&devfreq->dev,
1262 "failed to resume devfreq device\n");
1264 mutex_unlock(&devfreq_list_lock);
1268 * devfreq_add_governor() - Add devfreq governor
1269 * @governor: the devfreq governor to be added
1271 int devfreq_add_governor(struct devfreq_governor *governor)
1273 struct devfreq_governor *g;
1274 struct devfreq *devfreq;
1278 pr_err("%s: Invalid parameters.\n", __func__);
1282 mutex_lock(&devfreq_list_lock);
1283 g = find_devfreq_governor(governor->name);
1285 pr_err("%s: governor %s already registered\n", __func__,
1291 list_add(&governor->node, &devfreq_governor_list);
1293 list_for_each_entry(devfreq, &devfreq_list, node) {
1295 struct device *dev = devfreq->dev.parent;
1297 if (!strncmp(devfreq->governor->name, governor->name,
1298 DEVFREQ_NAME_LEN)) {
1299 /* The following should never occur */
1300 if (devfreq->governor) {
1302 "%s: Governor %s already present\n",
1303 __func__, devfreq->governor->name);
1304 ret = devfreq->governor->event_handler(devfreq,
1305 DEVFREQ_GOV_STOP, NULL);
1308 "%s: Governor %s stop = %d\n",
1310 devfreq->governor->name, ret);
1314 devfreq->governor = governor;
1315 ret = devfreq->governor->event_handler(devfreq,
1316 DEVFREQ_GOV_START, NULL);
1318 dev_warn(dev, "%s: Governor %s start=%d\n",
1319 __func__, devfreq->governor->name,
1326 mutex_unlock(&devfreq_list_lock);
1330 EXPORT_SYMBOL(devfreq_add_governor);
1332 static void devm_devfreq_remove_governor(void *governor)
1334 WARN_ON(devfreq_remove_governor(governor));
1338 * devm_devfreq_add_governor() - Add devfreq governor
1339 * @dev: device which adds devfreq governor
1340 * @governor: the devfreq governor to be added
1342 * This is a resource-managed variant of devfreq_add_governor().
1344 int devm_devfreq_add_governor(struct device *dev,
1345 struct devfreq_governor *governor)
1349 err = devfreq_add_governor(governor);
1353 return devm_add_action_or_reset(dev, devm_devfreq_remove_governor,
1356 EXPORT_SYMBOL(devm_devfreq_add_governor);
1359 * devfreq_remove_governor() - Remove devfreq feature from a device.
1360 * @governor: the devfreq governor to be removed
1362 int devfreq_remove_governor(struct devfreq_governor *governor)
1364 struct devfreq_governor *g;
1365 struct devfreq *devfreq;
1369 pr_err("%s: Invalid parameters.\n", __func__);
1373 mutex_lock(&devfreq_list_lock);
1374 g = find_devfreq_governor(governor->name);
1376 pr_err("%s: governor %s not registered\n", __func__,
1381 list_for_each_entry(devfreq, &devfreq_list, node) {
1383 struct device *dev = devfreq->dev.parent;
1385 if (!strncmp(devfreq->governor->name, governor->name,
1386 DEVFREQ_NAME_LEN)) {
1387 /* we should have a devfreq governor! */
1388 if (!devfreq->governor) {
1389 dev_warn(dev, "%s: Governor %s NOT present\n",
1390 __func__, governor->name);
1394 ret = devfreq->governor->event_handler(devfreq,
1395 DEVFREQ_GOV_STOP, NULL);
1397 dev_warn(dev, "%s: Governor %s stop=%d\n",
1398 __func__, devfreq->governor->name,
1401 devfreq->governor = NULL;
1405 list_del(&governor->node);
1407 mutex_unlock(&devfreq_list_lock);
1411 EXPORT_SYMBOL(devfreq_remove_governor);
1413 static ssize_t name_show(struct device *dev,
1414 struct device_attribute *attr, char *buf)
1416 struct devfreq *df = to_devfreq(dev);
1417 return sprintf(buf, "%s\n", dev_name(df->dev.parent));
1419 static DEVICE_ATTR_RO(name);
1421 static ssize_t governor_show(struct device *dev,
1422 struct device_attribute *attr, char *buf)
1424 struct devfreq *df = to_devfreq(dev);
1429 return sprintf(buf, "%s\n", df->governor->name);
1432 static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
1433 const char *buf, size_t count)
1435 struct devfreq *df = to_devfreq(dev);
1437 char str_governor[DEVFREQ_NAME_LEN + 1];
1438 const struct devfreq_governor *governor, *prev_governor;
1443 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
1447 mutex_lock(&devfreq_list_lock);
1448 governor = try_then_request_governor(str_governor);
1449 if (IS_ERR(governor)) {
1450 ret = PTR_ERR(governor);
1453 if (df->governor == governor) {
1456 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
1457 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
1463 * Stop the current governor and remove the specific sysfs files
1464 * which depend on current governor.
1466 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1468 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1469 __func__, df->governor->name, ret);
1472 remove_sysfs_files(df, df->governor);
1475 * Start the new governor and create the specific sysfs files
1476 * which depend on the new governor.
1478 prev_governor = df->governor;
1479 df->governor = governor;
1480 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1482 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1483 __func__, df->governor->name, ret);
1485 /* Restore previous governor */
1486 df->governor = prev_governor;
1487 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1490 "%s: reverting to Governor %s failed (%d)\n",
1491 __func__, prev_governor->name, ret);
1492 df->governor = NULL;
1498 * Create the sysfs files for the new governor. But if failed to start
1499 * the new governor, restore the sysfs files of previous governor.
1501 create_sysfs_files(df, df->governor);
1504 mutex_unlock(&devfreq_list_lock);
1510 static DEVICE_ATTR_RW(governor);
1512 static ssize_t available_governors_show(struct device *d,
1513 struct device_attribute *attr,
1516 struct devfreq *df = to_devfreq(d);
1522 mutex_lock(&devfreq_list_lock);
1525 * The devfreq with immutable governor (e.g., passive) shows
1526 * only own governor.
1528 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
1529 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
1530 "%s ", df->governor->name);
1532 * The devfreq device shows the registered governor except for
1533 * immutable governors such as passive governor .
1536 struct devfreq_governor *governor;
1538 list_for_each_entry(governor, &devfreq_governor_list, node) {
1539 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
1541 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1542 "%s ", governor->name);
1546 mutex_unlock(&devfreq_list_lock);
1548 /* Truncate the trailing space */
1552 count += sprintf(&buf[count], "\n");
1556 static DEVICE_ATTR_RO(available_governors);
1558 static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
1562 struct devfreq *df = to_devfreq(dev);
1567 if (df->profile->get_cur_freq &&
1568 !df->profile->get_cur_freq(df->dev.parent, &freq))
1569 return sprintf(buf, "%lu\n", freq);
1571 return sprintf(buf, "%lu\n", df->previous_freq);
1573 static DEVICE_ATTR_RO(cur_freq);
1575 static ssize_t target_freq_show(struct device *dev,
1576 struct device_attribute *attr, char *buf)
1578 struct devfreq *df = to_devfreq(dev);
1580 return sprintf(buf, "%lu\n", df->previous_freq);
1582 static DEVICE_ATTR_RO(target_freq);
1584 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
1585 const char *buf, size_t count)
1587 struct devfreq *df = to_devfreq(dev);
1588 unsigned long value;
1592 * Protect against theoretical sysfs writes between
1593 * device_add and dev_pm_qos_add_request
1595 if (!dev_pm_qos_request_active(&df->user_min_freq_req))
1598 ret = sscanf(buf, "%lu", &value);
1602 /* Round down to kHz for PM QoS */
1603 ret = dev_pm_qos_update_request(&df->user_min_freq_req,
1604 value / HZ_PER_KHZ);
1611 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
1614 struct devfreq *df = to_devfreq(dev);
1615 unsigned long min_freq, max_freq;
1617 mutex_lock(&df->lock);
1618 devfreq_get_freq_range(df, &min_freq, &max_freq);
1619 mutex_unlock(&df->lock);
1621 return sprintf(buf, "%lu\n", min_freq);
1623 static DEVICE_ATTR_RW(min_freq);
1625 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
1626 const char *buf, size_t count)
1628 struct devfreq *df = to_devfreq(dev);
1629 unsigned long value;
1633 * Protect against theoretical sysfs writes between
1634 * device_add and dev_pm_qos_add_request
1636 if (!dev_pm_qos_request_active(&df->user_max_freq_req))
1639 ret = sscanf(buf, "%lu", &value);
1644 * PM QoS frequencies are in kHz so we need to convert. Convert by
1645 * rounding upwards so that the acceptable interval never shrinks.
1647 * For example if the user writes "666666666" to sysfs this value will
1648 * be converted to 666667 kHz and back to 666667000 Hz before an OPP
1649 * lookup, this ensures that an OPP of 666666666Hz is still accepted.
1651 * A value of zero means "no limit".
1654 value = DIV_ROUND_UP(value, HZ_PER_KHZ);
1656 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
1658 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
1665 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
1668 struct devfreq *df = to_devfreq(dev);
1669 unsigned long min_freq, max_freq;
1671 mutex_lock(&df->lock);
1672 devfreq_get_freq_range(df, &min_freq, &max_freq);
1673 mutex_unlock(&df->lock);
1675 return sprintf(buf, "%lu\n", max_freq);
1677 static DEVICE_ATTR_RW(max_freq);
1679 static ssize_t available_frequencies_show(struct device *d,
1680 struct device_attribute *attr,
1683 struct devfreq *df = to_devfreq(d);
1690 mutex_lock(&df->lock);
1692 for (i = 0; i < df->max_state; i++)
1693 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1694 "%lu ", df->freq_table[i]);
1696 mutex_unlock(&df->lock);
1697 /* Truncate the trailing space */
1701 count += sprintf(&buf[count], "\n");
1705 static DEVICE_ATTR_RO(available_frequencies);
1707 static ssize_t trans_stat_show(struct device *dev,
1708 struct device_attribute *attr, char *buf)
1710 struct devfreq *df = to_devfreq(dev);
1713 unsigned int max_state;
1717 max_state = df->max_state;
1720 return scnprintf(buf, PAGE_SIZE, "Not Supported.\n");
1722 mutex_lock(&df->lock);
1723 if (!df->stop_polling &&
1724 devfreq_update_status(df, df->previous_freq)) {
1725 mutex_unlock(&df->lock);
1728 mutex_unlock(&df->lock);
1730 len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n");
1731 len += scnprintf(buf + len, PAGE_SIZE - len, " :");
1732 for (i = 0; i < max_state; i++) {
1733 if (len >= PAGE_SIZE - 1)
1735 len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu",
1738 if (len >= PAGE_SIZE - 1)
1739 return PAGE_SIZE - 1;
1741 len += scnprintf(buf + len, PAGE_SIZE - len, " time(ms)\n");
1743 for (i = 0; i < max_state; i++) {
1744 if (len >= PAGE_SIZE - 1)
1746 if (df->freq_table[i] == df->previous_freq)
1747 len += scnprintf(buf + len, PAGE_SIZE - len, "*");
1749 len += scnprintf(buf + len, PAGE_SIZE - len, " ");
1750 if (len >= PAGE_SIZE - 1)
1753 len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu:",
1755 for (j = 0; j < max_state; j++) {
1756 if (len >= PAGE_SIZE - 1)
1758 len += scnprintf(buf + len, PAGE_SIZE - len, "%10u",
1759 df->stats.trans_table[(i * max_state) + j]);
1761 if (len >= PAGE_SIZE - 1)
1763 len += scnprintf(buf + len, PAGE_SIZE - len, "%10llu\n", (u64)
1764 jiffies64_to_msecs(df->stats.time_in_state[i]));
1767 if (len < PAGE_SIZE - 1)
1768 len += scnprintf(buf + len, PAGE_SIZE - len, "Total transition : %u\n",
1769 df->stats.total_trans);
1771 if (len >= PAGE_SIZE - 1) {
1772 pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n");
1779 static ssize_t trans_stat_store(struct device *dev,
1780 struct device_attribute *attr,
1781 const char *buf, size_t count)
1783 struct devfreq *df = to_devfreq(dev);
1789 if (df->max_state == 0)
1792 err = kstrtoint(buf, 10, &value);
1793 if (err || value != 0)
1796 mutex_lock(&df->lock);
1797 memset(df->stats.time_in_state, 0, (df->max_state *
1798 sizeof(*df->stats.time_in_state)));
1799 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
1802 df->stats.total_trans = 0;
1803 df->stats.last_update = get_jiffies_64();
1804 mutex_unlock(&df->lock);
1808 static DEVICE_ATTR_RW(trans_stat);
1810 static struct attribute *devfreq_attrs[] = {
1811 &dev_attr_name.attr,
1812 &dev_attr_governor.attr,
1813 &dev_attr_available_governors.attr,
1814 &dev_attr_cur_freq.attr,
1815 &dev_attr_available_frequencies.attr,
1816 &dev_attr_target_freq.attr,
1817 &dev_attr_min_freq.attr,
1818 &dev_attr_max_freq.attr,
1819 &dev_attr_trans_stat.attr,
1822 ATTRIBUTE_GROUPS(devfreq);
1824 static ssize_t polling_interval_show(struct device *dev,
1825 struct device_attribute *attr, char *buf)
1827 struct devfreq *df = to_devfreq(dev);
1832 return sprintf(buf, "%d\n", df->profile->polling_ms);
1835 static ssize_t polling_interval_store(struct device *dev,
1836 struct device_attribute *attr,
1837 const char *buf, size_t count)
1839 struct devfreq *df = to_devfreq(dev);
1846 ret = sscanf(buf, "%u", &value);
1850 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1855 static DEVICE_ATTR_RW(polling_interval);
1857 static ssize_t timer_show(struct device *dev,
1858 struct device_attribute *attr, char *buf)
1860 struct devfreq *df = to_devfreq(dev);
1865 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
1868 static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
1869 const char *buf, size_t count)
1871 struct devfreq *df = to_devfreq(dev);
1872 char str_timer[DEVFREQ_NAME_LEN + 1];
1876 if (!df->governor || !df->profile)
1879 ret = sscanf(buf, "%16s", str_timer);
1883 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
1884 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
1895 if (df->profile->timer == timer) {
1900 mutex_lock(&df->lock);
1901 df->profile->timer = timer;
1902 mutex_unlock(&df->lock);
1904 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1906 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1907 __func__, df->governor->name, ret);
1911 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1913 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1914 __func__, df->governor->name, ret);
1916 return ret ? ret : count;
1918 static DEVICE_ATTR_RW(timer);
1920 #define CREATE_SYSFS_FILE(df, name) \
1923 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \
1925 dev_warn(&df->dev, \
1926 "Unable to create attr(%s)\n", "##name"); \
1930 /* Create the specific sysfs files which depend on each governor. */
1931 static void create_sysfs_files(struct devfreq *devfreq,
1932 const struct devfreq_governor *gov)
1934 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1935 CREATE_SYSFS_FILE(devfreq, polling_interval);
1936 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1937 CREATE_SYSFS_FILE(devfreq, timer);
1940 /* Remove the specific sysfs files which depend on each governor. */
1941 static void remove_sysfs_files(struct devfreq *devfreq,
1942 const struct devfreq_governor *gov)
1944 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1945 sysfs_remove_file(&devfreq->dev.kobj,
1946 &dev_attr_polling_interval.attr);
1947 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1948 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);
1952 * devfreq_summary_show() - Show the summary of the devfreq devices
1953 * @s: seq_file instance to show the summary of devfreq devices
1956 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
1957 * It helps that user can know the detailed information of the devfreq devices.
1959 * Return 0 always because it shows the information without any data change.
1961 static int devfreq_summary_show(struct seq_file *s, void *data)
1963 struct devfreq *devfreq;
1964 struct devfreq *p_devfreq = NULL;
1965 unsigned long cur_freq, min_freq, max_freq;
1966 unsigned int polling_ms;
1969 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
1978 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
1979 "------------------------------",
1980 "------------------------------",
1988 mutex_lock(&devfreq_list_lock);
1990 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
1991 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
1992 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
1993 DEVFREQ_NAME_LEN)) {
1994 struct devfreq_passive_data *data = devfreq->data;
1997 p_devfreq = data->parent;
2003 mutex_lock(&devfreq->lock);
2004 cur_freq = devfreq->previous_freq;
2005 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
2006 timer = devfreq->profile->timer;
2008 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
2009 polling_ms = devfreq->profile->polling_ms;
2012 mutex_unlock(&devfreq->lock);
2015 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
2016 dev_name(&devfreq->dev),
2017 p_devfreq ? dev_name(&p_devfreq->dev) : "null",
2018 devfreq->governor->name,
2019 polling_ms ? timer_name[timer] : "null",
2026 mutex_unlock(&devfreq_list_lock);
2030 DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
2032 static int __init devfreq_init(void)
2034 devfreq_class = class_create("devfreq");
2035 if (IS_ERR(devfreq_class)) {
2036 pr_err("%s: couldn't create class\n", __FILE__);
2037 return PTR_ERR(devfreq_class);
2040 devfreq_wq = create_freezable_workqueue("devfreq_wq");
2042 class_destroy(devfreq_class);
2043 pr_err("%s: couldn't create workqueue\n", __FILE__);
2046 devfreq_class->dev_groups = devfreq_groups;
2048 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
2049 debugfs_create_file("devfreq_summary", 0444,
2050 devfreq_debugfs, NULL,
2051 &devfreq_summary_fops);
2055 subsys_initcall(devfreq_init);
2058 * The following are helper functions for devfreq user device drivers with
2063 * devfreq_recommended_opp() - Helper function to get proper OPP for the
2064 * freq value given to target callback.
2065 * @dev: The devfreq user device. (parent of devfreq)
2066 * @freq: The frequency given to target function
2067 * @flags: Flags handed from devfreq framework.
2069 * The callers are required to call dev_pm_opp_put() for the returned OPP after
2072 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
2073 unsigned long *freq,
2076 struct dev_pm_opp *opp;
2078 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
2079 /* The freq is an upper bound. opp should be lower */
2080 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
2082 /* If not available, use the closest opp */
2083 if (opp == ERR_PTR(-ERANGE))
2084 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
2086 /* The freq is an lower bound. opp should be higher */
2087 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
2089 /* If not available, use the closest opp */
2090 if (opp == ERR_PTR(-ERANGE))
2091 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
2096 EXPORT_SYMBOL(devfreq_recommended_opp);
2099 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
2100 * for any changes in the OPP availability
2102 * @dev: The devfreq user device. (parent of devfreq)
2103 * @devfreq: The devfreq object.
2105 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
2107 return dev_pm_opp_register_notifier(dev, &devfreq->nb);
2109 EXPORT_SYMBOL(devfreq_register_opp_notifier);
2112 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
2113 * notified for any changes in the OPP
2114 * availability changes anymore.
2115 * @dev: The devfreq user device. (parent of devfreq)
2116 * @devfreq: The devfreq object.
2118 * At exit() callback of devfreq_dev_profile, this must be included if
2119 * devfreq_recommended_opp is used.
2121 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
2123 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
2125 EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
2127 static void devm_devfreq_opp_release(struct device *dev, void *res)
2129 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
2133 * devm_devfreq_register_opp_notifier() - Resource-managed
2134 * devfreq_register_opp_notifier()
2135 * @dev: The devfreq user device. (parent of devfreq)
2136 * @devfreq: The devfreq object.
2138 int devm_devfreq_register_opp_notifier(struct device *dev,
2139 struct devfreq *devfreq)
2141 struct devfreq **ptr;
2144 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
2148 ret = devfreq_register_opp_notifier(dev, devfreq);
2155 devres_add(dev, ptr);
2159 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
2162 * devm_devfreq_unregister_opp_notifier() - Resource-managed
2163 * devfreq_unregister_opp_notifier()
2164 * @dev: The devfreq user device. (parent of devfreq)
2165 * @devfreq: The devfreq object.
2167 void devm_devfreq_unregister_opp_notifier(struct device *dev,
2168 struct devfreq *devfreq)
2170 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
2171 devm_devfreq_dev_match, devfreq));
2173 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
2176 * devfreq_register_notifier() - Register a driver with devfreq
2177 * @devfreq: The devfreq object.
2178 * @nb: The notifier block to register.
2179 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2181 int devfreq_register_notifier(struct devfreq *devfreq,
2182 struct notifier_block *nb,
2191 case DEVFREQ_TRANSITION_NOTIFIER:
2192 ret = srcu_notifier_chain_register(
2193 &devfreq->transition_notifier_list, nb);
2201 EXPORT_SYMBOL(devfreq_register_notifier);
2204 * devfreq_unregister_notifier() - Unregister a driver with devfreq
2205 * @devfreq: The devfreq object.
2206 * @nb: The notifier block to be unregistered.
2207 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2209 int devfreq_unregister_notifier(struct devfreq *devfreq,
2210 struct notifier_block *nb,
2219 case DEVFREQ_TRANSITION_NOTIFIER:
2220 ret = srcu_notifier_chain_unregister(
2221 &devfreq->transition_notifier_list, nb);
2229 EXPORT_SYMBOL(devfreq_unregister_notifier);
2231 struct devfreq_notifier_devres {
2232 struct devfreq *devfreq;
2233 struct notifier_block *nb;
2237 static void devm_devfreq_notifier_release(struct device *dev, void *res)
2239 struct devfreq_notifier_devres *this = res;
2241 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
2245 * devm_devfreq_register_notifier()
2246 * - Resource-managed devfreq_register_notifier()
2247 * @dev: The devfreq user device. (parent of devfreq)
2248 * @devfreq: The devfreq object.
2249 * @nb: The notifier block to be unregistered.
2250 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2252 int devm_devfreq_register_notifier(struct device *dev,
2253 struct devfreq *devfreq,
2254 struct notifier_block *nb,
2257 struct devfreq_notifier_devres *ptr;
2260 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
2265 ret = devfreq_register_notifier(devfreq, nb, list);
2271 ptr->devfreq = devfreq;
2274 devres_add(dev, ptr);
2278 EXPORT_SYMBOL(devm_devfreq_register_notifier);
2281 * devm_devfreq_unregister_notifier()
2282 * - Resource-managed devfreq_unregister_notifier()
2283 * @dev: The devfreq user device. (parent of devfreq)
2284 * @devfreq: The devfreq object.
2285 * @nb: The notifier block to be unregistered.
2286 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2288 void devm_devfreq_unregister_notifier(struct device *dev,
2289 struct devfreq *devfreq,
2290 struct notifier_block *nb,
2293 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
2294 devm_devfreq_dev_match, devfreq));
2296 EXPORT_SYMBOL(devm_devfreq_unregister_notifier);