diff options
Diffstat (limited to 'drivers/devfreq')
-rw-r--r-- | drivers/devfreq/Kconfig | 8 | ||||
-rw-r--r-- | drivers/devfreq/devfreq.c | 926 | ||||
-rw-r--r-- | drivers/devfreq/exynos4_bus.c | 145 | ||||
-rw-r--r-- | drivers/devfreq/governor.h | 17 | ||||
-rw-r--r-- | drivers/devfreq/governor_performance.c | 38 | ||||
-rw-r--r-- | drivers/devfreq/governor_powersave.c | 38 | ||||
-rw-r--r-- | drivers/devfreq/governor_simpleondemand.c | 55 | ||||
-rw-r--r-- | drivers/devfreq/governor_userspace.c | 45 |
8 files changed, 912 insertions, 360 deletions
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index f6b0a6e2ea50..0f079be13305 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -30,7 +30,7 @@ if PM_DEVFREQ comment "DEVFREQ Governors" config DEVFREQ_GOV_SIMPLE_ONDEMAND - bool "Simple Ondemand" + tristate "Simple Ondemand" help Chooses frequency based on the recent load on the device. Works similar as ONDEMAND governor of CPUFREQ does. A device with @@ -39,7 +39,7 @@ config DEVFREQ_GOV_SIMPLE_ONDEMAND values to the governor with data field at devfreq_add_device(). config DEVFREQ_GOV_PERFORMANCE - bool "Performance" + tristate "Performance" help Sets the frequency at the maximum available frequency. This governor always returns UINT_MAX as frequency so that @@ -47,7 +47,7 @@ config DEVFREQ_GOV_PERFORMANCE at any time. config DEVFREQ_GOV_POWERSAVE - bool "Powersave" + tristate "Powersave" help Sets the frequency at the minimum available frequency. This governor always returns 0 as frequency so that @@ -55,7 +55,7 @@ config DEVFREQ_GOV_POWERSAVE at any time. config DEVFREQ_GOV_USERSPACE - bool "Userspace" + tristate "Userspace" help Sets the frequency at the user specified one. This governor returns the user configured frequency if there diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index b146d76f04cf..3b367973a802 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -27,21 +27,17 @@ #include <linux/hrtimer.h> #include "governor.h" -struct class *devfreq_class; +static struct class *devfreq_class; /* - * devfreq_work periodically monitors every registered device. - * The minimum polling interval is one jiffy. The polling interval is - * determined by the minimum polling period among all polling devfreq - * devices. The resolution of polling interval is one jiffy. + * devfreq core provides delayed work based load monitoring helper + * functions. Governors can use these or can implement their own + * monitoring mechanism. */ -static bool polling; static struct workqueue_struct *devfreq_wq; -static struct delayed_work devfreq_work; - -/* wait removing if this is to be removed */ -static struct devfreq *wait_remove_device; +/* 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); @@ -73,6 +69,79 @@ static struct devfreq *find_device_devfreq(struct device *dev) } /** + * 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. * @@ -90,6 +159,9 @@ int update_devfreq(struct devfreq *devfreq) return -EINVAL; } + if (!devfreq->governor) + return -EINVAL; + /* Reevaluate the proper frequency */ err = devfreq->governor->get_target_freq(devfreq, &freq); if (err) @@ -116,16 +188,173 @@ int update_devfreq(struct devfreq *devfreq) 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 + * @nb: the notifier_block (supposed to be devfreq->nb) + * @type: not used + * @devp: not used * * Called by a notifier that uses devfreq->nb. */ @@ -143,59 +372,34 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, } /** - * _remove_devfreq() - Remove devfreq from the device. + * _remove_devfreq() - Remove devfreq from the list and release its resources. * @devfreq: the devfreq struct * @skip: skip calling device_unregister(). - * - * Note that the caller should lock devfreq->lock before calling - * this. _remove_devfreq() will unlock it and free devfreq - * internally. devfreq_list_lock should be locked by the caller - * as well (not relased at return) - * - * Lock usage: - * devfreq->lock: locked before call. - * unlocked at return (and freed) - * devfreq_list_lock: locked before call. - * kept locked at return. - * if devfreq is centrally polled. - * - * Freed memory: - * devfreq */ static void _remove_devfreq(struct devfreq *devfreq, bool skip) { - if (!mutex_is_locked(&devfreq->lock)) { - WARN(true, "devfreq->lock must be locked by the caller.\n"); - return; - } - if (!devfreq->governor->no_central_polling && - !mutex_is_locked(&devfreq_list_lock)) { - WARN(true, "devfreq_list_lock must be locked by the caller.\n"); + 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->being_removed) - return; - - devfreq->being_removed = true; + if (devfreq->governor) + devfreq->governor->event_handler(devfreq, + DEVFREQ_GOV_STOP, NULL); if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); - if (devfreq->governor->exit) - devfreq->governor->exit(devfreq); - if (!skip && get_device(&devfreq->dev)) { device_unregister(&devfreq->dev); put_device(&devfreq->dev); } - if (!devfreq->governor->no_central_polling) - list_del(&devfreq->node); - - mutex_unlock(&devfreq->lock); mutex_destroy(&devfreq->lock); - kfree(devfreq); } @@ -210,163 +414,39 @@ static void _remove_devfreq(struct devfreq *devfreq, bool skip) static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); - bool central_polling = !devfreq->governor->no_central_polling; - - /* - * If devfreq_dev_release() was called by device_unregister() of - * _remove_devfreq(), we cannot mutex_lock(&devfreq->lock) and - * being_removed is already set. This also partially checks the case - * where devfreq_dev_release() is called from a thread other than - * the one called _remove_devfreq(); however, this case is - * dealt completely with another following being_removed check. - * - * Because being_removed is never being - * unset, we do not need to worry about race conditions on - * being_removed. - */ - if (devfreq->being_removed) - return; - - if (central_polling) - mutex_lock(&devfreq_list_lock); - - mutex_lock(&devfreq->lock); - /* - * Check being_removed flag again for the case where - * devfreq_dev_release() was called in a thread other than the one - * possibly called _remove_devfreq(). - */ - if (devfreq->being_removed) { - mutex_unlock(&devfreq->lock); - goto out; - } - - /* devfreq->lock is unlocked and removed in _removed_devfreq() */ _remove_devfreq(devfreq, true); - -out: - if (central_polling) - mutex_unlock(&devfreq_list_lock); -} - -/** - * devfreq_monitor() - Periodically poll devfreq objects. - * @work: the work struct used to run devfreq_monitor periodically. - * - */ -static void devfreq_monitor(struct work_struct *work) -{ - static unsigned long last_polled_at; - struct devfreq *devfreq, *tmp; - int error; - unsigned long jiffies_passed; - unsigned long next_jiffies = ULONG_MAX, now = jiffies; - struct device *dev; - - /* Initially last_polled_at = 0, polling every device at bootup */ - jiffies_passed = now - last_polled_at; - last_polled_at = now; - if (jiffies_passed == 0) - jiffies_passed = 1; - - mutex_lock(&devfreq_list_lock); - list_for_each_entry_safe(devfreq, tmp, &devfreq_list, node) { - mutex_lock(&devfreq->lock); - dev = devfreq->dev.parent; - - /* Do not remove tmp for a while */ - wait_remove_device = tmp; - - if (devfreq->governor->no_central_polling || - devfreq->next_polling == 0) { - mutex_unlock(&devfreq->lock); - continue; - } - mutex_unlock(&devfreq_list_lock); - - /* - * Reduce more next_polling if devfreq_wq took an extra - * delay. (i.e., CPU has been idled.) - */ - if (devfreq->next_polling <= jiffies_passed) { - error = update_devfreq(devfreq); - - /* Remove a devfreq with an error. */ - if (error && error != -EAGAIN) { - - dev_err(dev, "Due to update_devfreq error(%d), devfreq(%s) is removed from the device\n", - error, devfreq->governor->name); - - /* - * Unlock devfreq before locking the list - * in order to avoid deadlock with - * find_device_devfreq or others - */ - mutex_unlock(&devfreq->lock); - mutex_lock(&devfreq_list_lock); - /* Check if devfreq is already removed */ - if (IS_ERR(find_device_devfreq(dev))) - continue; - mutex_lock(&devfreq->lock); - /* This unlocks devfreq->lock and free it */ - _remove_devfreq(devfreq, false); - continue; - } - devfreq->next_polling = devfreq->polling_jiffies; - } else { - devfreq->next_polling -= jiffies_passed; - } - - if (devfreq->next_polling) - next_jiffies = (next_jiffies > devfreq->next_polling) ? - devfreq->next_polling : next_jiffies; - - mutex_unlock(&devfreq->lock); - mutex_lock(&devfreq_list_lock); - } - wait_remove_device = NULL; - mutex_unlock(&devfreq_list_lock); - - if (next_jiffies > 0 && next_jiffies < ULONG_MAX) { - polling = true; - queue_delayed_work(devfreq_wq, &devfreq_work, next_jiffies); - } else { - polling = false; - } } /** * devfreq_add_device() - Add devfreq feature to the device * @dev: the device to add devfreq feature. * @profile: device-specific profile to run devfreq. - * @governor: the policy to choose frequency. + * @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 struct devfreq_governor *governor, + const char *governor_name, void *data) { struct devfreq *devfreq; + struct devfreq_governor *governor; int err = 0; - if (!dev || !profile || !governor) { + if (!dev || !profile || !governor_name) { dev_err(dev, "%s: Invalid parameters.\n", __func__); return ERR_PTR(-EINVAL); } - - if (!governor->no_central_polling) { - 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; - } + 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); @@ -383,92 +463,316 @@ struct devfreq *devfreq_add_device(struct device *dev, devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; devfreq->profile = profile; - devfreq->governor = governor; + strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; devfreq->data = data; - devfreq->next_polling = devfreq->polling_jiffies - = msecs_to_jiffies(devfreq->profile->polling_ms); 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; } - if (governor->init) - err = governor->init(devfreq); - if (err) - goto err_init; - mutex_unlock(&devfreq->lock); - if (governor->no_central_polling) - goto out; - mutex_lock(&devfreq_list_lock); - list_add(&devfreq->node, &devfreq_list); - if (devfreq_wq && devfreq->next_polling && !polling) { - polling = true; - queue_delayed_work(devfreq_wq, &devfreq_work, - devfreq->next_polling); - } + 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); -out: + 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: - mutex_unlock(&devfreq->lock); 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 + * @devfreq: the devfreq instance to be removed */ int devfreq_remove_device(struct devfreq *devfreq) { - bool central_polling; + 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; - central_polling = !devfreq->governor->no_central_polling; + 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; + } - if (central_polling) { - mutex_lock(&devfreq_list_lock); - while (wait_remove_device == devfreq) { - mutex_unlock(&devfreq_list_lock); - schedule(); - mutex_lock(&devfreq_list_lock); + 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); + } } } - mutex_lock(&devfreq->lock); - _remove_devfreq(devfreq, false); /* it unlocks devfreq->lock */ +err_out: + mutex_unlock(&devfreq_list_lock); - if (central_polling) - mutex_unlock(&devfreq_list_lock); + return err; +} +EXPORT_SYMBOL(devfreq_add_governor); - return 0; +/** + * 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); } @@ -486,39 +790,19 @@ static ssize_t store_polling_interval(struct device *dev, unsigned int value; int ret; + if (!df->governor) + return -EINVAL; + ret = sscanf(buf, "%u", &value); if (ret != 1) - goto out; - - mutex_lock(&df->lock); - df->profile->polling_ms = value; - df->next_polling = df->polling_jiffies - = msecs_to_jiffies(value); - mutex_unlock(&df->lock); + return -EINVAL; + df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); ret = count; - if (df->governor->no_central_polling) - goto out; - - mutex_lock(&devfreq_list_lock); - if (df->next_polling > 0 && !polling) { - polling = true; - queue_delayed_work(devfreq_wq, &devfreq_work, - df->next_polling); - } - mutex_unlock(&devfreq_list_lock); -out: return ret; } -static ssize_t show_central_polling(struct device *dev, - struct device_attribute *attr, char *buf) -{ - return sprintf(buf, "%d\n", - !to_devfreq(dev)->governor->no_central_polling); -} - static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -529,7 +813,7 @@ static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, ret = sscanf(buf, "%lu", &value); if (ret != 1) - goto out; + return -EINVAL; mutex_lock(&df->lock); max = df->max_freq; @@ -543,7 +827,6 @@ static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, ret = count; unlock: mutex_unlock(&df->lock); -out: return ret; } @@ -563,7 +846,7 @@ static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr, ret = sscanf(buf, "%lu", &value); if (ret != 1) - goto out; + return -EINVAL; mutex_lock(&df->lock); min = df->min_freq; @@ -577,7 +860,6 @@ static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr, ret = count; unlock: mutex_unlock(&df->lock); -out: return ret; } @@ -587,34 +869,92 @@ static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr, 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; + ssize_t count = 0; + unsigned long freq = 0; + + rcu_read_lock(); + do { + opp = opp_find_freq_ceil(dev, &freq); + if (IS_ERR(opp)) + break; + + count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), + "%lu ", freq); + freq++; + } while (1); + 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, show_governor, NULL), + __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(central_polling, S_IRUGO, show_central_polling, NULL), + __ATTR(available_frequencies, S_IRUGO, show_available_freqs, NULL), + __ATTR(target_freq, S_IRUGO, show_target_freq, NULL), __ATTR(poll |