/* * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework * for Non-CPU Devices. * * Copyright (C) 2011 Samsung Electronics * MyungJoo Ham <myungjoo.ham@samsung.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h>#include <linux/sched.h>#include <linux/errno.h>#include <linux/err.h>#include <linux/init.h>#include <linux/export.h>#include <linux/slab.h>#include <linux/stat.h>#include <linux/pm_opp.h>#include <linux/devfreq.h>#include <linux/workqueue.h>#include <linux/platform_device.h>#include <linux/list.h>#include <linux/printk.h>#include <linux/hrtimer.h>#include <linux/of.h>#include "governor.h" #define MAX(a,b) ((a > b) ? a : b)#define MIN(a,b) ((a < b) ? a : b) static struct class *devfreq_class; /* * devfreq core provides delayed work based load monitoring helper * functions. Governors can use these or can implement their own * monitoring mechanism. */static struct workqueue_struct *devfreq_wq; /* The list of all device-devfreq governors */static LIST_HEAD(devfreq_governor_list);/* The list of all device-devfreq */static LIST_HEAD(devfreq_list);static DEFINE_MUTEX(devfreq_list_lock); /** * find_device_devfreq() - find devfreq struct using device pointer * @dev: device pointer used to lookup device devfreq. * * Search the list of device devfreqs and return the matched device's * devfreq info. devfreq_list_lock should be held by the caller. */static struct devfreq *find_device_devfreq(struct device *dev){ struct devfreq *tmp_devfreq; if (IS_ERR_OR_NULL(dev)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } WARN(!mutex_is_locked(&devfreq_list_lock), "devfreq_list_lock must be locked."); list_for_each_entry(tmp_devfreq, &devfreq_list, node) { if (tmp_devfreq->dev.parent == dev) return tmp_devfreq; } return ERR_PTR(-ENODEV);} static unsigned long find_available_min_freq(struct devfreq *devfreq){ struct dev_pm_opp *opp; unsigned long min_freq = 0; opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq); if (IS_ERR(opp)) min_freq = 0; else dev_pm_opp_put(opp); return min_freq;} static unsigned long find_available_max_freq(struct devfreq *devfreq){ struct dev_pm_opp *opp; unsigned long max_freq = ULONG_MAX; opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq); if (IS_ERR(opp)) max_freq = 0; else dev_pm_opp_put(opp); return max_freq;} /** * devfreq_get_freq_level() - Lookup freq_table for the frequency * @devfreq: the devfreq instance * @freq: the target frequency */static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq){ int lev; for (lev = 0; lev < devfreq->profile->max_state; lev++) if (freq == devfreq->profile->freq_table[lev]) return lev; return -EINVAL;} static int set_freq_table(struct devfreq *devfreq){ struct devfreq_dev_profile *profile = devfreq->profile; struct dev_pm_opp *opp; unsigned long freq; int i, count; /* Initialize the freq_table from OPP table */ count = dev_pm_opp_get_opp_count(devfreq->dev.parent); if (count <= 0) return -EINVAL; profile->max_state = count; profile->freq_table = devm_kcalloc(devfreq->dev.parent, profile->max_state, sizeof(*profile->freq_table), GFP_KERNEL); if (!profile->freq_table) { profile->max_state = 0; return -ENOMEM; } for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq); if (IS_ERR(opp)) { devm_kfree(devfreq->dev.parent, profile->freq_table); profile->max_state = 0; return PTR_ERR(opp); } dev_pm_opp_put(opp); profile->freq_table[i] = freq; } return 0;} /** * devfreq_update_status() - Update statistics of devfreq behavior * @devfreq: the devfreq instance * @freq: the update target frequency */int devfreq_update_status(struct devfreq *devfreq, unsigned long freq){ int lev, prev_lev, ret = 0; unsigned long cur_time; cur_time = jiffies; /* Immediately exit if previous_freq is not initialized yet. */ if (!devfreq->previous_freq) goto out; prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); if (prev_lev < 0) { ret = prev_lev; goto out; } devfreq->time_in_state[prev_lev] += cur_time - devfreq->last_stat_updated; lev = devfreq_get_freq_level(devfreq, freq); if (lev < 0) { ret = lev; goto out; } if (lev != prev_lev) { devfreq->trans_table[(prev_lev * devfreq->profile->max_state) + lev]++; devfreq->total_trans++; } out: devfreq->last_stat_updated = cur_time; return ret;}EXPORT_SYMBOL(devfreq_update_status); /** * find_devfreq_governor() - find devfreq governor from name * @name: name of the governor * * Search the list of devfreq governors and return the matched * governor's pointer. devfreq_list_lock should be held by the caller. */static struct devfreq_governor *find_devfreq_governor(const char *name){ struct devfreq_governor *tmp_governor; if (IS_ERR_OR_NULL(name)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } WARN(!mutex_is_locked(&devfreq_list_lock), "devfreq_list_lock must be locked."); list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) return tmp_governor; } return ERR_PTR(-ENODEV);} static int devfreq_notify_transition(struct devfreq *devfreq, struct devfreq_freqs *freqs, unsigned int state){ if (!devfreq) return -EINVAL; switch (state) { case DEVFREQ_PRECHANGE: srcu_notifier_call_chain(&devfreq->transition_notifier_list, DEVFREQ_PRECHANGE, freqs); break; case DEVFREQ_POSTCHANGE: srcu_notifier_call_chain(&devfreq->transition_notifier_list, DEVFREQ_POSTCHANGE, freqs); break; default: return -EINVAL; } return 0;} /* Load monitoring helper functions for governors use */ /** * update_devfreq() - Reevaluate the device and configure frequency. * @devfreq: the devfreq instance. * * Note: Lock devfreq->lock before calling update_devfreq * This function is exported for governors. */int update_devfreq(struct devfreq *devfreq){ struct devfreq_freqs freqs; unsigned long freq, cur_freq, min_freq, max_freq; int err = 0; u32 flags = 0; if (!mutex_is_locked(&devfreq->lock)) { WARN(true, "devfreq->lock must be locked by the caller.\n"); return -EINVAL; } if (!devfreq->governor) return -EINVAL; /* Reevaluate the proper frequency */ err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) return err; /* * Adjust the frequency with user freq, QoS and available freq. * * List from the highest priority * max_freq * min_freq */ max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq); min_freq = MAX(devfreq->scaling_min_freq, devfreq->min_freq); if (min_freq && freq < min_freq) { freq = min_freq; flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ } if (max_freq && freq > max_freq) { freq = max_freq; flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ } if (devfreq->profile->get_cur_freq) devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); else cur_freq = devfreq->previous_freq; freqs.old = cur_freq; freqs.new = freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); if (err) { freqs.new = cur_freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); return err; } freqs.new = freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); if (devfreq_update_status(devfreq, freq)) dev_err(&devfreq->dev, "Couldn't update frequency transition information.\n"); devfreq->previous_freq = freq; return err;}EXPORT_SYMBOL(update_devfreq); /** * devfreq_monitor() - Periodically poll devfreq objects. * @work: the work struct used to run devfreq_monitor periodically. * */static void devfreq_monitor(struct work_struct *work){ int err; struct devfreq *devfreq = container_of(work, struct devfreq, work.work); mutex_lock(&devfreq->lock); err = update_devfreq(devfreq); if (err) dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err); queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); mutex_unlock(&devfreq->lock);} /** * devfreq_monitor_start() - Start load monitoring of devfreq instance * @devfreq: the devfreq instance. * * Helper function for starting devfreq device load monitoing. By * default delayed work based monitoring is supported. Function * to be called from governor in response to DEVFREQ_GOV_START * event when device is added to devfreq framework. */void devfreq_monitor_start(struct devfreq *devfreq){ INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); if (devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms));}EXPORT_SYMBOL(devfreq_monitor_start); /** * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to stop devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_STOP * event when device is removed from devfreq framework. */void devfreq_monitor_stop(struct devfreq *devfreq){ cancel_delayed_work_sync(&devfreq->work);}EXPORT_SYMBOL(devfreq_monitor_stop); /** * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to suspend devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_SUSPEND * event or when polling interval is set to zero. * * Note: Though this function is same as devfreq_monitor_stop(), * intentionally kept separate to provide hooks for collecting * transition statistics. */void devfreq_monitor_suspend(struct devfreq *devfreq){ mutex_lock(&devfreq->lock); if (devfreq->stop_polling) { mutex_unlock(&devfreq->lock); return; } devfreq_update_status(devfreq, devfreq->previous_freq); devfreq->stop_polling = true; mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work);}EXPORT_SYMBOL(devfreq_monitor_suspend); /** * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to resume devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_RESUME * event or when polling interval is set to non-zero. */void devfreq_monitor_resume(struct devfreq *devfreq){ unsigned long freq; mutex_lock(&devfreq->lock); if (!devfreq->stop_polling) goto out; if (!delayed_work_pending(&devfreq->work) && devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); devfreq->last_stat_updated = jiffies; devfreq->stop_polling = false; if (devfreq->profile->get_cur_freq && !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) devfreq->previous_freq = freq; out: mutex_unlock(&devfreq->lock);}EXPORT_SYMBOL(devfreq_monitor_resume); /** * devfreq_interval_update() - Update device devfreq monitoring interval * @devfreq: the devfreq instance. * @delay: new polling interval to be set. * * Helper function to set new load monitoring polling interval. Function * to be called from governor in response to DEVFREQ_GOV_INTERVAL event. */void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay){ unsigned int cur_delay = devfreq->profile->polling_ms; unsigned int new_delay = *delay; mutex_lock(&devfreq->lock); devfreq->profile->polling_ms = new_delay; if (devfreq->stop_polling) goto out; /* if new delay is zero, stop polling */ if (!new_delay) { mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work); return; } /* if current delay is zero, start polling with new delay */ if (!cur_delay) { queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); goto out; } /* if current delay is greater than new delay, restart polling */ if (cur_delay > new_delay) { mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work); mutex_lock(&devfreq->lock); if (!devfreq->stop_polling) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); }out: mutex_unlock(&devfreq->lock);}EXPORT_SYMBOL(devfreq_interval_update); /** * devfreq_notifier_call() - Notify that the device frequency requirements * has been changed out of devfreq framework. * @nb: the notifier_block (supposed to be devfreq->nb) * @type: not used * @devp: not used * * Called by a notifier that uses devfreq->nb. */static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, void *devp){ struct devfreq *devfreq = container_of(nb, struct devfreq, nb); int ret; mutex_lock(&devfreq->lock); devfreq->scaling_min_freq = find_available_min_freq(devfreq);Lines 1–500 of 1533. 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/* * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework * for Non-CPU Devices. * * Copyright (C) 2011 Samsung Electronics * MyungJoo Ham <myungjoo.ham@samsung.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/errno.h> #include <linux/err.h> #include <linux/init.h> #include <linux/export.h> #include <linux/slab.h> #include <linux/stat.h> #include <linux/pm_opp.h> #include <linux/devfreq.h> #include <linux/workqueue.h> #include <linux/platform_device.h> #include <linux/list.h> #include <linux/printk.h> #include <linux/hrtimer.h> #include <linux/of.h> #include "governor.h" #define MAX(a,b) ((a > b) ? a : b) #define MIN(a,b) ((a < b) ? a : b) static struct class *devfreq_class; /* * devfreq core provides delayed work based load monitoring helper * functions. Governors can use these or can implement their own * monitoring mechanism. */ static struct workqueue_struct *devfreq_wq; /* The list of all device-devfreq governors */ static LIST_HEAD(devfreq_governor_list); /* The list of all device-devfreq */ static LIST_HEAD(devfreq_list); static DEFINE_MUTEX(devfreq_list_lock); /** * find_device_devfreq() - find devfreq struct using device pointer * @dev: device pointer used to lookup device devfreq. * * Search the list of device devfreqs and return the matched device's * devfreq info. devfreq_list_lock should be held by the caller. */ static struct devfreq *find_device_devfreq(struct device *dev) { struct devfreq *tmp_devfreq; if (IS_ERR_OR_NULL(dev)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } WARN(!mutex_is_locked(&devfreq_list_lock), "devfreq_list_lock must be locked."); list_for_each_entry(tmp_devfreq, &devfreq_list, node) { if (tmp_devfreq->dev.parent == dev) return tmp_devfreq; } return ERR_PTR(-ENODEV); } static unsigned long find_available_min_freq(struct devfreq *devfreq) { struct dev_pm_opp *opp; unsigned long min_freq = 0; opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq); if (IS_ERR(opp)) min_freq = 0; else dev_pm_opp_put(opp); return min_freq; } static unsigned long find_available_max_freq(struct devfreq *devfreq) { struct dev_pm_opp *opp; unsigned long max_freq = ULONG_MAX; opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq); if (IS_ERR(opp)) max_freq = 0; else dev_pm_opp_put(opp); return max_freq; } /** * devfreq_get_freq_level() - Lookup freq_table for the frequency * @devfreq: the devfreq instance * @freq: the target frequency */ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) { int lev; for (lev = 0; lev < devfreq->profile->max_state; lev++) if (freq == devfreq->profile->freq_table[lev]) return lev; return -EINVAL; } static int set_freq_table(struct devfreq *devfreq) { struct devfreq_dev_profile *profile = devfreq->profile; struct dev_pm_opp *opp; unsigned long freq; int i, count; /* Initialize the freq_table from OPP table */ count = dev_pm_opp_get_opp_count(devfreq->dev.parent); if (count <= 0) return -EINVAL; profile->max_state = count; profile->freq_table = devm_kcalloc(devfreq->dev.parent, profile->max_state, sizeof(*profile->freq_table), GFP_KERNEL); if (!profile->freq_table) { profile->max_state = 0; return -ENOMEM; } for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq); if (IS_ERR(opp)) { devm_kfree(devfreq->dev.parent, profile->freq_table); profile->max_state = 0; return PTR_ERR(opp); } dev_pm_opp_put(opp); profile->freq_table[i] = freq; } return 0; } /** * devfreq_update_status() - Update statistics of devfreq behavior * @devfreq: the devfreq instance * @freq: the update target frequency */ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) { int lev, prev_lev, ret = 0; unsigned long cur_time; cur_time = jiffies; /* Immediately exit if previous_freq is not initialized yet. */ if (!devfreq->previous_freq) goto out; prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); if (prev_lev < 0) { ret = prev_lev; goto out; } devfreq->time_in_state[prev_lev] += cur_time - devfreq->last_stat_updated; lev = devfreq_get_freq_level(devfreq, freq); if (lev < 0) { ret = lev; goto out; } if (lev != prev_lev) { devfreq->trans_table[(prev_lev * devfreq->profile->max_state) + lev]++; devfreq->total_trans++; } out: devfreq->last_stat_updated = cur_time; return ret; } EXPORT_SYMBOL(devfreq_update_status); /** * find_devfreq_governor() - find devfreq governor from name * @name: name of the governor * * Search the list of devfreq governors and return the matched * governor's pointer. devfreq_list_lock should be held by the caller. */ static struct devfreq_governor *find_devfreq_governor(const char *name) { struct devfreq_governor *tmp_governor; if (IS_ERR_OR_NULL(name)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } WARN(!mutex_is_locked(&devfreq_list_lock), "devfreq_list_lock must be locked."); list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) return tmp_governor; } return ERR_PTR(-ENODEV); } static int devfreq_notify_transition(struct devfreq *devfreq, struct devfreq_freqs *freqs, unsigned int state) { if (!devfreq) return -EINVAL; switch (state) { case DEVFREQ_PRECHANGE: srcu_notifier_call_chain(&devfreq->transition_notifier_list, DEVFREQ_PRECHANGE, freqs); break; case DEVFREQ_POSTCHANGE: srcu_notifier_call_chain(&devfreq->transition_notifier_list, DEVFREQ_POSTCHANGE, freqs); break; default: return -EINVAL; } return 0; } /* Load monitoring helper functions for governors use */ /** * update_devfreq() - Reevaluate the device and configure frequency. * @devfreq: the devfreq instance. * * Note: Lock devfreq->lock before calling update_devfreq * This function is exported for governors. */ int update_devfreq(struct devfreq *devfreq) { struct devfreq_freqs freqs; unsigned long freq, cur_freq, min_freq, max_freq; int err = 0; u32 flags = 0; if (!mutex_is_locked(&devfreq->lock)) { WARN(true, "devfreq->lock must be locked by the caller.\n"); return -EINVAL; } if (!devfreq->governor) return -EINVAL; /* Reevaluate the proper frequency */ err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) return err; /* * Adjust the frequency with user freq, QoS and available freq. * * List from the highest priority * max_freq * min_freq */ max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq); min_freq = MAX(devfreq->scaling_min_freq, devfreq->min_freq); if (min_freq && freq < min_freq) { freq = min_freq; flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ } if (max_freq && freq > max_freq) { freq = max_freq; flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ } if (devfreq->profile->get_cur_freq) devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); else cur_freq = devfreq->previous_freq; freqs.old = cur_freq; freqs.new = freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); if (err) { freqs.new = cur_freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); return err; } freqs.new = freq; devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); if (devfreq_update_status(devfreq, freq)) dev_err(&devfreq->dev, "Couldn't update frequency transition information.\n"); devfreq->previous_freq = freq; return err; } EXPORT_SYMBOL(update_devfreq); /** * devfreq_monitor() - Periodically poll devfreq objects. * @work: the work struct used to run devfreq_monitor periodically. * */ static void devfreq_monitor(struct work_struct *work) { int err; struct devfreq *devfreq = container_of(work, struct devfreq, work.work); mutex_lock(&devfreq->lock); err = update_devfreq(devfreq); if (err) dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err); queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); mutex_unlock(&devfreq->lock); } /** * devfreq_monitor_start() - Start load monitoring of devfreq instance * @devfreq: the devfreq instance. * * Helper function for starting devfreq device load monitoing. By * default delayed work based monitoring is supported. Function * to be called from governor in response to DEVFREQ_GOV_START * event when device is added to devfreq framework. */ void devfreq_monitor_start(struct devfreq *devfreq) { INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); if (devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); } EXPORT_SYMBOL(devfreq_monitor_start); /** * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to stop devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_STOP * event when device is removed from devfreq framework. */ void devfreq_monitor_stop(struct devfreq *devfreq) { cancel_delayed_work_sync(&devfreq->work); } EXPORT_SYMBOL(devfreq_monitor_stop); /** * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to suspend devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_SUSPEND * event or when polling interval is set to zero. * * Note: Though this function is same as devfreq_monitor_stop(), * intentionally kept separate to provide hooks for collecting * transition statistics. */ void devfreq_monitor_suspend(struct devfreq *devfreq) { mutex_lock(&devfreq->lock); if (devfreq->stop_polling) { mutex_unlock(&devfreq->lock); return; } devfreq_update_status(devfreq, devfreq->previous_freq); devfreq->stop_polling = true; mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work); } EXPORT_SYMBOL(devfreq_monitor_suspend); /** * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance * @devfreq: the devfreq instance. * * Helper function to resume devfreq device load monitoing. Function * to be called from governor in response to DEVFREQ_GOV_RESUME * event or when polling interval is set to non-zero. */ void devfreq_monitor_resume(struct devfreq *devfreq) { unsigned long freq; mutex_lock(&devfreq->lock); if (!devfreq->stop_polling) goto out; if (!delayed_work_pending(&devfreq->work) && devfreq->profile->polling_ms) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); devfreq->last_stat_updated = jiffies; devfreq->stop_polling = false; if (devfreq->profile->get_cur_freq && !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) devfreq->previous_freq = freq; out: mutex_unlock(&devfreq->lock); } EXPORT_SYMBOL(devfreq_monitor_resume); /** * devfreq_interval_update() - Update device devfreq monitoring interval * @devfreq: the devfreq instance. * @delay: new polling interval to be set. * * Helper function to set new load monitoring polling interval. Function * to be called from governor in response to DEVFREQ_GOV_INTERVAL event. */ void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay) { unsigned int cur_delay = devfreq->profile->polling_ms; unsigned int new_delay = *delay; mutex_lock(&devfreq->lock); devfreq->profile->polling_ms = new_delay; if (devfreq->stop_polling) goto out; /* if new delay is zero, stop polling */ if (!new_delay) { mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work); return; } /* if current delay is zero, start polling with new delay */ if (!cur_delay) { queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); goto out; } /* if current delay is greater than new delay, restart polling */ if (cur_delay > new_delay) { mutex_unlock(&devfreq->lock); cancel_delayed_work_sync(&devfreq->work); mutex_lock(&devfreq->lock); if (!devfreq->stop_polling) queue_delayed_work(devfreq_wq, &devfreq->work, msecs_to_jiffies(devfreq->profile->polling_ms)); } out: mutex_unlock(&devfreq->lock); } EXPORT_SYMBOL(devfreq_interval_update); /** * devfreq_notifier_call() - Notify that the device frequency requirements * has been changed out of devfreq framework. * @nb: the notifier_block (supposed to be devfreq->nb) * @type: not used * @devp: not used * * Called by a notifier that uses devfreq->nb. */ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, void *devp) { struct devfreq *devfreq = container_of(nb, struct devfreq, nb); int ret; mutex_lock(&devfreq->lock); devfreq->scaling_min_freq = find_available_min_freq(devfreq);