diff options
Diffstat (limited to 'drivers/video/backlight/backlight.c')
| -rw-r--r-- | drivers/video/backlight/backlight.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 157057c79ca..6e1446ae7f5 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -73,6 +73,26 @@ static inline void backlight_unregister_fb(struct backlight_device *bd) } #endif /* CONFIG_FB */ +static void backlight_generate_event(struct backlight_device *bd, + enum backlight_update_reason reason) +{ + char *envp[2]; + + switch (reason) { + case BACKLIGHT_UPDATE_SYSFS: + envp[0] = "SOURCE=sysfs"; + break; + case BACKLIGHT_UPDATE_HOTKEY: + envp[0] = "SOURCE=hotkey"; + break; + default: + envp[0] = "SOURCE=unknown"; + break; + } + envp[1] = NULL; + kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp); +} + static ssize_t backlight_show_power(struct device *dev, struct device_attribute *attr,char *buf) { @@ -142,6 +162,8 @@ static ssize_t backlight_store_brightness(struct device *dev, } mutex_unlock(&bd->ops_lock); + backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS); + return rc; } @@ -214,6 +236,25 @@ static struct device_attribute bl_device_attributes[] = { }; /** + * backlight_force_update - tell the backlight subsystem that hardware state + * has changed + * @bd: the backlight device to update + * + * Updates the internal state of the backlight in response to a hardware event, + * and generate a uevent to notify userspace + */ +void backlight_force_update(struct backlight_device *bd, + enum backlight_update_reason reason) +{ + mutex_lock(&bd->ops_lock); + if (bd->ops && bd->ops->get_brightness) + bd->props.brightness = bd->ops->get_brightness(bd); + mutex_unlock(&bd->ops_lock); + backlight_generate_event(bd, reason); +} +EXPORT_SYMBOL(backlight_force_update); + +/** * backlight_device_register - create and register a new object of * backlight_device class. * @name: the name of the new object(must be the same as the name of the |