diff options
| -rw-r--r-- | drivers/devfreq/devfreq.c | 91 | ||||
| -rw-r--r-- | drivers/devfreq/governor.h | 4 | ||||
| -rw-r--r-- | include/linux/devfreq.h | 3 |
3 files changed, 98 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index e0002c5cbadc..679ac424472f 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -36,6 +36,8 @@ static struct class *devfreq_class; */ 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); @@ -111,6 +113,32 @@ static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) 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 */ /** @@ -515,6 +543,69 @@ int devfreq_resume_device(struct devfreq *devfreq) } 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; + 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); + +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; + 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__, + g->name); + err = -EINVAL; + goto err_out; + } + + 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) { diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h index 26432ac0a398..fad7d6321978 100644 --- a/drivers/devfreq/governor.h +++ b/drivers/devfreq/governor.h @@ -34,4 +34,8 @@ extern void devfreq_monitor_suspend(struct devfreq *devfreq); extern void devfreq_monitor_resume(struct devfreq *devfreq); extern void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay); + +extern int devfreq_add_governor(struct devfreq_governor *governor); +extern int devfreq_remove_governor(struct devfreq_governor *governor); + #endif /* _GOVERNOR_H */ diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index bc35c4aee6a3..6484a3f8dda8 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -92,6 +92,7 @@ struct devfreq_dev_profile { /** * struct devfreq_governor - Devfreq policy governor + * @node: list node - contains registered devfreq governors * @name: Governor's name * @get_target_freq: Returns desired operating frequency for the device. * Basically, get_target_freq will run @@ -107,6 +108,8 @@ struct devfreq_dev_profile { * Note that the callbacks are called with devfreq->lock locked by devfreq. */ struct devfreq_governor { + struct list_head node; + const char name[DEVFREQ_NAME_LEN]; int (*get_target_freq)(struct devfreq *this, unsigned long *freq); int (*event_handler)(struct devfreq *devfreq, |