| /* |
| * 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/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 "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_set_freq_limits() - Set min and max frequency from freq_table |
| * @devfreq: the devfreq instance |
| */ |
| static void devfreq_set_freq_limits(struct devfreq *devfreq) |
| { |
| int idx; |
| unsigned long min = ~0, max = 0; |
| |
| if (!devfreq->profile->freq_table) |
| return; |
| |
| for (idx = 0; idx < devfreq->profile->max_state; idx++) { |
| if (min > devfreq->profile->freq_table[idx]) |
| min = devfreq->profile->freq_table[idx]; |
| if (max < devfreq->profile->freq_table[idx]) |
| max = devfreq->profile->freq_table[idx]; |
| } |
| |
| devfreq->min_freq = min; |
| devfreq->max_freq = max; |
| } |
| |
| /** |
| * devfreq_get_freq_level() - Lookup freq_table for the frequency |
| * @devfreq: the devfreq instance |
| * @freq: the target frequency |
| */ |
| 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; |
| } |
| EXPORT_SYMBOL(devfreq_get_freq_level); |
| |
| /** |
| * 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, ret = 0; |
| unsigned long cur_time; |
| |
| cur_time = jiffies; |
| |
| 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; |
| } |
| |
| /** |
| * 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, &flags); |
| 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(*(devfreq->time_in_state)) * |
| devfreq->profile->max_state, |
| GFP_KERNEL); |
| devfreq->last_stat_updated = jiffies; |
| devfreq_set_freq_limits(devfreq); |
| |
| 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) { |
| dev_err(dev, "%s: Unable to start governor for the device\n", |
| __func__); |
| goto err_init; |
| } |
| |
| return devfreq; |
| |
| err_init: |
| list_del(&devfreq->node); |
| device_unregister(&devfreq->dev); |
| err_dev: |
| kfree(devfreq); |
| err_out: |
| return ERR_PTR(err); |
| } |
| EXPORT_SYMBOL(devfreq_add_device); |
| |
| /** |
| * devfreq_remove_device() - Remove devfreq feature from a device. |
| * @devfreq: the devfreq instance to be removed |
| */ |
| int devfreq_remove_device(struct devfreq *devfreq) |
| { |
| if (!devfreq) |
| return -EINVAL; |
| |
| _remove_devfreq(devfreq, false); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(devfreq_remove_device); |
| |
| /** |
| * devfreq_suspend_device() - Suspend devfreq of a device. |
| * @devfreq: the devfreq instance to be suspended |
| */ |
| int devfreq_suspend_device(struct devfreq *devfreq) |
| { |
| if (!devfreq) |
| return -EINVAL; |
| |
| if (!devfreq->governor) |
| return 0; |
| |
| return devfreq->governor->event_handler(devfreq, |
| DEVFREQ_GOV_SUSPEND, NULL); |
| } |
| EXPORT_SYMBOL(devfreq_suspend_device); |
| |
| /** |
| * devfreq_resume_device() - Resume devfreq of a device. |
| * @devfreq: the devfreq instance to be resumed |
| */ |
| int devfreq_resume_device(struct devfreq *devfreq) |
| { |
| if (!devfreq) |
| return -EINVAL; |
| |
| if (!devfreq->governor) |
| return 0; |
| |
| return devfreq->governor->event_handler(devfreq, |
| DEVFREQ_GOV_RESUME, NULL); |
| } |
| EXPORT_SYMBOL(devfreq_resume_device); |
| |
| /** |
| * devfreq_add_governor() - Add devfreq governor |
| * @governor: the devfreq governor to be added |
| */ |
| int devfreq_add_governor(struct devfreq_governor *governor) |
| { |
| struct devfreq_governor *g; |
| struct devfreq *devfreq; |
| int err = 0; |
| |
| if (!governor) { |
| pr_err("%s: Invalid parameters.\n", __func__); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&devfreq_list_lock); |
| g = find_devfreq_governor(governor->name); |
| if (!IS_ERR(g)) { |
| pr_err("%s: governor %s already registered\n", __func__, |
| g->name); |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| list_add(&governor->node, &devfreq_governor_list); |
| |
| list_for_each_entry(devfreq, &devfreq_list, node) { |
| int ret = 0; |
| struct device *dev = devfreq->dev.parent; |
| |
| if (!strncmp(devfreq->governor_name, governor->name, |
| DEVFREQ_NAME_LEN)) { |
| /* The following should never occur */ |
| if (devfreq->governor) { |
| dev_warn(dev, |
| "%s: Governor %s already present\n", |
| __func__, devfreq->governor->name); |
| ret = devfreq->governor->event_handler(devfreq, |
| DEVFREQ_GOV_STOP, NULL); |
| if (ret) { |
| dev_warn(dev, |
| "%s: Governor %s stop = %d\n", |
| __func__, |
| devfreq->governor->name, ret); |
| } |
| /* Fall through */ |
| } |
| devfreq->governor = governor; |
| ret = devfreq->governor->event_handler(devfreq, |
| DEVFREQ_GOV_START, NULL); |
| if (ret) { |
| dev_warn(dev, "%s: Governor %s start=%d\n", |
| __func__, devfreq->governor->name, |
| ret); |
| } |
| } |
| } |
| |
| err_out: |
| mutex_unlock(&devfreq_list_lock); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(devfreq_add_governor); |
| |
| /** |
| * devfreq_remove_device() - Remove devfreq feature from a device. |
| * @governor: the devfreq governor to be removed |
| */ |
| int devfreq_remove_governor(struct devfreq_governor *governor) |
| { |
| struct devfreq_governor *g; |
| struct devfreq *devfreq; |
| int err = 0; |
| |
| if (!governor) { |
| pr_err("%s: Invalid parameters.\n", __func__); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&devfreq_list_lock); |
| g = find_devfreq_governor(governor->name); |
| if (IS_ERR(g)) { |
| pr_err("%s: governor %s not registered\n", __func__, |
| governor->name); |
| err = PTR_ERR(g); |
| goto err_out; |
| } |
| list_for_each_entry(devfreq, &devfreq_list, node) { |
| int ret; |
| struct device *dev = devfreq->dev.parent; |
| |
| if (!strncmp(devfreq->governor_name, governor->name, |
| DEVFREQ_NAME_LEN)) { |
| /* we should have a devfreq governor! */ |
| if (!devfreq->governor) { |
| dev_warn(dev, "%s: Governor %s NOT present\n", |
| __func__, governor->name); |
| continue; |
| /* Fall through */ |
| } |
| ret = devfreq->governor->event_handler(devfreq, |
| DEVFREQ_GOV_STOP, NULL); |
| if (ret) { |
| dev_warn(dev, "%s: Governor %s stop=%d\n", |
| __func__, devfreq->governor->name, |
| ret); |
| } |
| devfreq->governor = NULL; |
| } |
| } |
| |
| list_del(&governor->node); |
| err_out: |
| mutex_unlock(&devfreq_list_lock); |
| |
| return err; |
| } |
| EXPORT_SYMBOL(devfreq_remove_governor); |
| |
| static ssize_t show_governor(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| if (!to_devfreq(dev)->governor) |
| return -EINVAL; |
| |
| return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); |
| } |
| |
| static ssize_t store_governor(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct devfreq *df = to_devfreq(dev); |
| int ret; |
| char str_governor[DEVFREQ_NAME_LEN + 1]; |
| struct devfreq_governor *governor; |
| |
| ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); |
| if (ret != 1) |
| return -EINVAL; |
| |
| mutex_lock(&devfreq_list_lock); |
| governor = find_devfreq_governor(str_governor); |
| if (IS_ERR(governor)) { |
| ret = PTR_ERR(governor); |
| goto out; |
| } |
| if (df->governor == governor) |
| goto out; |
| |
| if (df->governor) { |
| ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); |
| if (ret) { |
| dev_warn(dev, "%s: Governor %s not stopped(%d)\n", |
| __func__, df->governor->name, ret); |
| goto out; |
| } |
| } |
| df->governor = governor; |
| strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); |
| ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); |
| if (ret) |
| dev_warn(dev, "%s: Governor %s not started(%d)\n", |
| __func__, df->governor->name, ret); |
| out: |
| mutex_unlock(&devfreq_list_lock); |
| |
| if (!ret) |
| ret = count; |
| return ret; |
| } |
| static ssize_t show_available_governors(struct device *d, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct devfreq_governor *tmp_governor; |
| ssize_t count = 0; |
| |
| mutex_lock(&devfreq_list_lock); |
| list_for_each_entry(tmp_governor, &devfreq_governor_list, node) |
| count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), |
| "%s ", tmp_governor->name); |
| mutex_unlock(&devfreq_list_lock); |
| |
| /* Truncate the trailing space */ |
| if (count) |
| count--; |
| |
| count += sprintf(&buf[count], "\n"); |
| |
| return count; |
| } |
| |
| static ssize_t show_freq(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| unsigned long freq; |
| struct devfreq *devfreq = to_devfreq(dev); |
| |
| if (devfreq->profile->get_cur_freq && |
| !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) |
| return sprintf(buf, "%lu\n", freq); |
| |
| return sprintf(buf, "%lu\n", devfreq->previous_freq); |
| } |
| |
| static ssize_t show_target_freq(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); |
| } |
| |
| static ssize_t show_polling_interval(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); |
| } |
| |
| static ssize_t store_polling_interval(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct devfreq *df = to_devfreq(dev); |
| unsigned int value; |
| int ret; |
| |
| if (!df->governor) |
| return -EINVAL; |
| |
| ret = sscanf(buf, "%u", &value); |
| if (ret != 1) |
| return -EINVAL; |
| |
| df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); |
| ret = count; |
| |
| return ret; |
| } |
| |
| static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct devfreq *df = to_devfreq(dev); |
| unsigned long value; |
| int ret; |
| unsigned long max; |
| |
| ret = sscanf(buf, "%lu", &value); |
| if (ret != 1) |
| return -EINVAL; |
| |
| mutex_lock(&df->lock); |
| max = df->max_freq; |
| if (value && max && value > max) { |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| df->min_freq = value; |
| update_devfreq(df); |
| ret = count; |
| unlock: |
| mutex_unlock(&df->lock); |
| return ret; |
| } |
| |
| static ssize_t show_min_freq(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); |
| } |
| |
| static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct devfreq *df = to_devfreq(dev); |
| unsigned long value; |
| int ret; |
| unsigned long min; |
| |
| ret = sscanf(buf, "%lu", &value); |
| if (ret != 1) |
| return -EINVAL; |
| |
| mutex_lock(&df->lock); |
| min = df->min_freq; |
| if (value && min && value < min) { |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| df->max_freq = value; |
| update_devfreq(df); |
| ret = count; |
| unlock: |
| mutex_unlock(&df->lock); |
| return ret; |
| } |
| |
| static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); |
| } |
| |
| static ssize_t show_available_freqs(struct device *d, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct devfreq *df = to_devfreq(d); |
| struct device *dev = df->dev.parent; |
| struct opp *opp; |
| unsigned int i = 0, max_state = df->profile->max_state; |
| bool use_opp; |
| ssize_t count = 0; |
| unsigned long freq = 0; |
| |
| rcu_read_lock(); |
| use_opp = dev_pm_opp_get_opp_count(dev) > 0; |
| while (use_opp || (!use_opp && i < max_state)) { |
| if (use_opp) { |
| opp = dev_pm_opp_find_freq_ceil(dev, &freq); |
| if (IS_ERR(opp)) |
| break; |
| } else { |
| freq = df->profile->freq_table[i++]; |
| } |
| |
| count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), |
| "%lu ", freq); |
| freq++; |
| } |
| rcu_read_unlock(); |
| |
| /* Truncate the trailing space */ |
| if (count) |
| count--; |
| |
| count += sprintf(&buf[count], "\n"); |
| |
| return count; |
| } |
| |
| static ssize_t show_trans_table(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct devfreq *devfreq = to_devfreq(dev); |
| ssize_t len; |
| int i, j, err; |
| unsigned int max_state = devfreq->profile->max_state; |
| |
| err = devfreq_update_status(devfreq, devfreq->previous_freq); |
| if (err) |
| return 0; |
| |
| len = sprintf(buf, " From : To\n"); |
| len += sprintf(buf + len, " :"); |
| for (i = 0; i < max_state; i++) |
| len += sprintf(buf + len, "%8u", |
| devfreq->profile->freq_table[i]); |
| |
| len += sprintf(buf + len, " time(ms)\n"); |
| |
| for (i = 0; i < max_state; i++) { |
| if (devfreq->profile->freq_table[i] |
| == devfreq->previous_freq) { |
| len += sprintf(buf + len, "*"); |
| } else { |
| len += sprintf(buf + len, " "); |
| } |
| len += sprintf(buf + len, "%8u:", |
| devfreq->profile->freq_table[i]); |
| for (j = 0; j < max_state; j++) |
| len += sprintf(buf + len, "%8u", |
| devfreq->trans_table[(i * max_state) + j]); |
| len += sprintf(buf + len, "%10u\n", |
| jiffies_to_msecs(devfreq->time_in_state[i])); |
| } |
| |
| len += sprintf(buf + len, "Total transition : %u\n", |
| devfreq->total_trans); |
| return len; |
| } |
| |
| static struct device_attribute devfreq_attrs[] = { |
| __ATTR(governor, S_IRUGO | S_IWUSR, show_governor, store_governor), |
| __ATTR(available_governors, S_IRUGO, show_available_governors, NULL), |
| __ATTR(cur_freq, S_IRUGO, show_freq, NULL), |
| __ATTR(available_frequencies, S_IRUGO, show_available_freqs, NULL), |
| __ATTR(target_freq, S_IRUGO, show_target_freq, NULL), |
| __ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval, |
| store_polling_interval), |
| __ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq), |
| __ATTR(max_freq, S_IRUGO | S_IWUSR, show_max_freq, store_max_freq), |
| __ATTR(trans_stat, S_IRUGO, show_trans_table, NULL), |
| { }, |
| }; |
| |
| static int __init devfreq_init(void) |
| { |
| devfreq_class = class_create(THIS_MODULE, "devfreq"); |
| if (IS_ERR(devfreq_class)) { |
| pr_err("%s: couldn't create class\n", __FILE__); |
| return PTR_ERR(devfreq_class); |
| } |
| |
| devfreq_wq = create_freezable_workqueue("devfreq_wq"); |
| if (IS_ERR(devfreq_wq)) { |
| class_destroy(devfreq_class); |
| pr_err("%s: couldn't create workqueue\n", __FILE__); |
| return PTR_ERR(devfreq_wq); |
| } |
| devfreq_class->dev_attrs = devfreq_attrs; |
| |
| return 0; |
| } |
| subsys_initcall(devfreq_init); |
| |
| static void __exit devfreq_exit(void) |
| { |
| class_destroy(devfreq_class); |
| destroy_workqueue(devfreq_wq); |
| } |
| module_exit(devfreq_exit); |
| |
| /* |
| * The followings are helper functions for devfreq user device drivers with |
| * OPP framework. |
| */ |
| |
| /** |
| * devfreq_recommended_opp() - Helper function to get proper OPP for the |
| * freq value given to target callback. |
| * @dev: The devfreq user device. (parent of devfreq) |
| * @freq: The frequency given to target function |
| * @flags: Flags handed from devfreq framework. |
| * |
| * Locking: This function must be called under rcu_read_lock(). opp is a rcu |
| * protected pointer. The reason for the same is that the opp pointer which is |
| * returned will remain valid for use with opp_get_{voltage, freq} only while |
| * under the locked area. The pointer returned must be used prior to unlocking |
| * with rcu_read_unlock() to maintain the integrity of the pointer. |
| */ |
| struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, |
| u32 flags) |
| { |
| struct opp *opp; |
| |
| if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { |
| /* The freq is an upper bound. opp should be lower */ |
| opp = dev_pm_opp_find_freq_floor(dev, freq); |
| |
| /* If not available, use the closest opp */ |
| if (opp == ERR_PTR(-ERANGE)) |
| opp = dev_pm_opp_find_freq_ceil(dev, freq); |
| } else { |
| /* The freq is an lower bound. opp should be higher */ |
| opp = dev_pm_opp_find_freq_ceil(dev, freq); |
| |
| /* If not available, use the closest opp */ |
| if (opp == ERR_PTR(-ERANGE)) |
| opp = dev_pm_opp_find_freq_floor(dev, freq); |
| } |
| |
| return opp; |
| } |
| |
| /** |
| * devfreq_register_opp_notifier() - Helper function to get devfreq notified |
| * for any changes in the OPP availability |
| * changes |
| * @dev: The devfreq user device. (parent of devfreq) |
| * @devfreq: The devfreq object. |
| */ |
| int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) |
| { |
| struct srcu_notifier_head *nh; |
| int ret = 0; |
| |
| rcu_read_lock(); |
| nh = dev_pm_opp_get_notifier(dev); |
| if (IS_ERR(nh)) |
| ret = PTR_ERR(nh); |
| rcu_read_unlock(); |
| if (!ret) |
| ret = srcu_notifier_chain_register(nh, &devfreq->nb); |
| |
| return ret; |
| } |
| |
| /** |
| * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq |
| * notified for any changes in the OPP |
| * availability changes anymore. |
| * @dev: The devfreq user device. (parent of devfreq) |
| * @devfreq: The devfreq object. |
| * |
| * At exit() callback of devfreq_dev_profile, this must be included if |
| * devfreq_recommended_opp is used. |
| */ |
| int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) |
| { |
| struct srcu_notifier_head *nh; |
| int ret = 0; |
| |
| rcu_read_lock(); |
| nh = dev_pm_opp_get_notifier(dev); |
| if (IS_ERR(nh)) |
| ret = PTR_ERR(nh); |
| rcu_read_unlock(); |
| if (!ret) |
| ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); |
| |
| return ret; |
| } |
| |
| MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); |
| MODULE_DESCRIPTION("devfreq class support"); |
| MODULE_LICENSE("GPL"); |