/* * 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/module.h>#include <linux/slab.h>#include <linux/stat.h>#include <linux/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 "governor.h" 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 (unlikely(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);} /** * 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;} /** * devfreq_update_status() - Update statistics of devfreq behavior * @devfreq: the devfreq instance * @freq: the update target frequency */static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq){ int lev, prev_lev; unsigned long cur_time; lev = devfreq_get_freq_level(devfreq, freq); if (lev < 0) return lev; cur_time = jiffies; devfreq->time_in_state[lev] += cur_time - devfreq->last_stat_updated; if (freq != devfreq->previous_freq) { prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); devfreq->trans_table[(prev_lev * devfreq->profile->max_state) + lev]++; devfreq->total_trans++; } devfreq->last_stat_updated = cur_time; return 0;} /** * 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 (unlikely(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);} /* 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){ unsigned long 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 freuqency with user freq and QoS. * * List from the highest proiority * max_freq (probably called by thermal when it's too hot) * min_freq */ if (devfreq->min_freq && freq < devfreq->min_freq) { freq = devfreq->min_freq; flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ } if (devfreq->max_freq && freq > devfreq->max_freq) { freq = devfreq->max_freq; flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ } err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); if (err) return err; if (devfreq->profile->freq_table) 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->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){ 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->stop_polling = false; 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); ret = update_devfreq(devfreq); mutex_unlock(&devfreq->lock); return ret;} /** * _remove_devfreq() - Remove devfreq from the list and release its resources. * @devfreq: the devfreq struct * @skip: skip calling device_unregister(). */static void _remove_devfreq(struct devfreq *devfreq, bool skip){ mutex_lock(&devfreq_list_lock); if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { mutex_unlock(&devfreq_list_lock); dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); return; } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); if (devfreq->governor) devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_STOP, NULL); if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); if (!skip && get_device(&devfreq->dev)) { device_unregister(&devfreq->dev); put_device(&devfreq->dev); } mutex_destroy(&devfreq->lock); kfree(devfreq);} /** * devfreq_dev_release() - Callback for struct device to release the device. * @dev: the devfreq device * * This calls _remove_devfreq() if _remove_devfreq() is not called. * Note that devfreq_dev_release() could be called by _remove_devfreq() as * well as by others unregistering the device. */static void devfreq_dev_release(struct device *dev){ struct devfreq *devfreq = to_devfreq(dev); _remove_devfreq(devfreq, true);} /** * devfreq_add_device() - Add devfreq feature to the device * @dev: the device to add devfreq feature. * @profile: device-specific profile to run devfreq. * @governor_name: name of the policy to choose frequency. * @data: private data for the governor. The devfreq framework does not * touch this value. */struct devfreq *devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data){ struct devfreq *devfreq; struct devfreq_governor *governor; int err = 0; if (!dev || !profile || !governor_name) { dev_err(dev, "%s: Invalid parameters.\n", __func__); return ERR_PTR(-EINVAL); } mutex_lock(&devfreq_list_lock); devfreq = find_device_devfreq(dev); mutex_unlock(&devfreq_list_lock); if (!IS_ERR(devfreq)) { dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); err = -EINVAL; goto err_out; } devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); if (!devfreq) { dev_err(dev, "%s: Unable to create devfreq for the device\n", __func__); err = -ENOMEM; goto err_out; } mutex_init(&devfreq->lock); mutex_lock(&devfreq->lock); devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; devfreq->profile = profile; strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; devfreq->data = data; devfreq->nb.notifier_call = devfreq_notifier_call; devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * devfreq->profile->max_state * devfreq->profile->max_state, GFP_KERNEL); devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) * devfreq->profile->max_state, GFP_KERNEL); devfreq->last_stat_updated = jiffies; dev_set_name(&devfreq->dev, dev_name(dev)); err = device_register(&devfreq->dev); if (err) { put_device(&devfreq->dev); mutex_unlock(&devfreq->lock); goto err_dev; } mutex_unlock(&devfreq->lock); mutex_lock(&devfreq_list_lock); list_add(&devfreq->node, &devfreq_list); governor = find_devfreq_governor(devfreq->governor_name); if (!IS_ERR(governor)) devfreq->governor = governor; if (devfreq->governor) err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START, NULL); mutex_unlock(&devfreq_list_lock); if (err) {Lines 1–500 of 1073. 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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/module.h> #include <linux/slab.h> #include <linux/stat.h> #include <linux/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 "governor.h" 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 (unlikely(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); } /** * 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; } /** * devfreq_update_status() - Update statistics of devfreq behavior * @devfreq: the devfreq instance * @freq: the update target frequency */ static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) { int lev, prev_lev; unsigned long cur_time; lev = devfreq_get_freq_level(devfreq, freq); if (lev < 0) return lev; cur_time = jiffies; devfreq->time_in_state[lev] += cur_time - devfreq->last_stat_updated; if (freq != devfreq->previous_freq) { prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); devfreq->trans_table[(prev_lev * devfreq->profile->max_state) + lev]++; devfreq->total_trans++; } devfreq->last_stat_updated = cur_time; return 0; } /** * 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 (unlikely(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); } /* 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) { unsigned long 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 freuqency with user freq and QoS. * * List from the highest proiority * max_freq (probably called by thermal when it's too hot) * min_freq */ if (devfreq->min_freq && freq < devfreq->min_freq) { freq = devfreq->min_freq; flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ } if (devfreq->max_freq && freq > devfreq->max_freq) { freq = devfreq->max_freq; flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ } err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); if (err) return err; if (devfreq->profile->freq_table) 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->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) { 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->stop_polling = false; 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); ret = update_devfreq(devfreq); mutex_unlock(&devfreq->lock); return ret; } /** * _remove_devfreq() - Remove devfreq from the list and release its resources. * @devfreq: the devfreq struct * @skip: skip calling device_unregister(). */ static void _remove_devfreq(struct devfreq *devfreq, bool skip) { mutex_lock(&devfreq_list_lock); if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { mutex_unlock(&devfreq_list_lock); dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); return; } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); if (devfreq->governor) devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_STOP, NULL); if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); if (!skip && get_device(&devfreq->dev)) { device_unregister(&devfreq->dev); put_device(&devfreq->dev); } mutex_destroy(&devfreq->lock); kfree(devfreq); } /** * devfreq_dev_release() - Callback for struct device to release the device. * @dev: the devfreq device * * This calls _remove_devfreq() if _remove_devfreq() is not called. * Note that devfreq_dev_release() could be called by _remove_devfreq() as * well as by others unregistering the device. */ static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); _remove_devfreq(devfreq, true); } /** * devfreq_add_device() - Add devfreq feature to the device * @dev: the device to add devfreq feature. * @profile: device-specific profile to run devfreq. * @governor_name: name of the policy to choose frequency. * @data: private data for the governor. The devfreq framework does not * touch this value. */ struct devfreq *devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, const char *governor_name, void *data) { struct devfreq *devfreq; struct devfreq_governor *governor; int err = 0; if (!dev || !profile || !governor_name) { dev_err(dev, "%s: Invalid parameters.\n", __func__); return ERR_PTR(-EINVAL); } mutex_lock(&devfreq_list_lock); devfreq = find_device_devfreq(dev); mutex_unlock(&devfreq_list_lock); if (!IS_ERR(devfreq)) { dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); err = -EINVAL; goto err_out; } devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); if (!devfreq) { dev_err(dev, "%s: Unable to create devfreq for the device\n", __func__); err = -ENOMEM; goto err_out; } mutex_init(&devfreq->lock); mutex_lock(&devfreq->lock); devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; devfreq->profile = profile; strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; devfreq->data = data; devfreq->nb.notifier_call = devfreq_notifier_call; devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * devfreq->profile->max_state * devfreq->profile->max_state, GFP_KERNEL); devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) * devfreq->profile->max_state, GFP_KERNEL); devfreq->last_stat_updated = jiffies; dev_set_name(&devfreq->dev, dev_name(dev)); err = device_register(&devfreq->dev); if (err) { put_device(&devfreq->dev); mutex_unlock(&devfreq->lock); goto err_dev; } mutex_unlock(&devfreq->lock); mutex_lock(&devfreq_list_lock); list_add(&devfreq->node, &devfreq_list); governor = find_devfreq_governor(devfreq->governor_name); if (!IS_ERR(governor)) devfreq->governor = governor; if (devfreq->governor) err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START, NULL); mutex_unlock(&devfreq_list_lock); if (err) {