From 4d71a4a12b130ad033219e6f58c74a64059415eb Mon Sep 17 00:00:00 2001 From: Jacek Anaszewski Date: Fri, 14 Nov 2014 02:50:18 -0800 Subject: leds: Add support for setting brightness in a synchronous way There are use cases when setting a LED brightness has to have immediate effect (e.g. setting a torch LED brightness). This patch extends LED subsystem to support such operations. The LED subsystem internal API __led_set_brightness is changed to led_set_brightness_async and new led_set_brightness_sync API is added. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Cc: Richard Purdie Signed-off-by: Bryan Wu --- drivers/leds/led-class.c | 10 ++++++---- drivers/leds/led-core.c | 18 +++++++++++++++--- drivers/leds/leds.h | 20 ++++++++++++++++---- drivers/leds/trigger/ledtrig-backlight.c | 8 ++++---- drivers/leds/trigger/ledtrig-default-on.c | 2 +- drivers/leds/trigger/ledtrig-gpio.c | 6 +++--- drivers/leds/trigger/ledtrig-heartbeat.c | 2 +- drivers/leds/trigger/ledtrig-oneshot.c | 4 ++-- drivers/leds/trigger/ledtrig-transient.c | 10 ++++++---- include/linux/leds.h | 8 ++++++++ 10 files changed, 62 insertions(+), 26 deletions(-) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 65722deb8d28..dbeebac38d31 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -55,7 +55,7 @@ static ssize_t brightness_store(struct device *dev, if (state == LED_OFF) led_trigger_remove(led_cdev); - __led_set_brightness(led_cdev, state); + led_set_brightness(led_cdev, state); ret = size; unlock: @@ -109,7 +109,7 @@ static void led_timer_function(unsigned long data) unsigned long delay; if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { - __led_set_brightness(led_cdev, LED_OFF); + led_set_brightness_async(led_cdev, LED_OFF); return; } @@ -132,7 +132,7 @@ static void led_timer_function(unsigned long data) delay = led_cdev->blink_delay_off; } - __led_set_brightness(led_cdev, brightness); + led_set_brightness_async(led_cdev, brightness); /* Return in next iteration if led is in one-shot mode and we are in * the final blink state so that the led is toggled each delay_on + @@ -158,7 +158,7 @@ static void set_brightness_delayed(struct work_struct *ws) led_stop_software_blink(led_cdev); - __led_set_brightness(led_cdev, led_cdev->delayed_set_value); + led_set_brightness_async(led_cdev, led_cdev->delayed_set_value); } /** @@ -233,6 +233,8 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) if (!led_cdev->max_brightness) led_cdev->max_brightness = LED_FULL; + led_cdev->flags |= SET_BRIGHTNESS_ASYNC; + led_update_brightness(led_cdev); INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index be6d9fa5e971..9886dace5ad2 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -42,13 +42,13 @@ static void led_set_software_blink(struct led_classdev *led_cdev, /* never on - just set to off */ if (!delay_on) { - __led_set_brightness(led_cdev, LED_OFF); + led_set_brightness_async(led_cdev, LED_OFF); return; } /* never off - just set to brightness */ if (!delay_off) { - __led_set_brightness(led_cdev, led_cdev->blink_brightness); + led_set_brightness_async(led_cdev, led_cdev->blink_brightness); return; } @@ -117,6 +117,8 @@ EXPORT_SYMBOL_GPL(led_stop_software_blink); void led_set_brightness(struct led_classdev *led_cdev, enum led_brightness brightness) { + int ret = 0; + /* delay brightness setting if need to stop soft-blink timer */ if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) { led_cdev->delayed_set_value = brightness; @@ -124,7 +126,17 @@ void led_set_brightness(struct led_classdev *led_cdev, return; } - __led_set_brightness(led_cdev, brightness); + if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) { + led_set_brightness_async(led_cdev, brightness); + return; + } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC) + ret = led_set_brightness_sync(led_cdev, brightness); + else + ret = -EINVAL; + + if (ret < 0) + dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n", + ret); } EXPORT_SYMBOL(led_set_brightness); diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h index 4c50365344a9..2348dbda5269 100644 --- a/drivers/leds/leds.h +++ b/drivers/leds/leds.h @@ -17,16 +17,28 @@ #include #include -static inline void __led_set_brightness(struct led_classdev *led_cdev, +static inline void led_set_brightness_async(struct led_classdev *led_cdev, enum led_brightness value) { - if (value > led_cdev->max_brightness) - value = led_cdev->max_brightness; - led_cdev->brightness = value; + led_cdev->brightness = min(value, led_cdev->max_brightness); + if (!(led_cdev->flags & LED_SUSPENDED)) led_cdev->brightness_set(led_cdev, value); } +static inline int led_set_brightness_sync(struct led_classdev *led_cdev, + enum led_brightness value) +{ + int ret = 0; + + led_cdev->brightness = min(value, led_cdev->max_brightness); + + if (!(led_cdev->flags & LED_SUSPENDED)) + ret = led_cdev->brightness_set_sync(led_cdev, + led_cdev->brightness); + return ret; +} + static inline int led_get_brightness(struct led_classdev *led_cdev) { return led_cdev->brightness; diff --git a/drivers/leds/trigger/ledtrig-backlight.c b/drivers/leds/trigger/ledtrig-backlight.c index 47e55aa9eefa..59eca17d9661 100644 --- a/drivers/leds/trigger/ledtrig-backlight.c +++ b/drivers/leds/trigger/ledtrig-backlight.c @@ -51,9 +51,9 @@ static int fb_notifier_callback(struct notifier_block *p, if ((n->old_status == UNBLANK) ^ n->invert) { n->brightness = led->brightness; - __led_set_brightness(led, LED_OFF); + led_set_brightness_async(led, LED_OFF); } else { - __led_set_brightness(led, n->brightness); + led_set_brightness_async(led, n->brightness); } n->old_status = new_status; @@ -89,9 +89,9 @@ static ssize_t bl_trig_invert_store(struct device *dev, /* After inverting, we need to update the LED. */ if ((n->old_status == BLANK) ^ n->invert) - __led_set_brightness(led, LED_OFF); + led_set_brightness_async(led, LED_OFF); else - __led_set_brightness(led, n->brightness); + led_set_brightness_async(led, n->brightness); return num; } diff --git a/drivers/leds/trigger/ledtrig-default-on.c b/drivers/leds/trigger/ledtrig-default-on.c index 81a91be8e18d..6f38f883aaf1 100644 --- a/drivers/leds/trigger/ledtrig-default-on.c +++ b/drivers/leds/trigger/ledtrig-default-on.c @@ -19,7 +19,7 @@ static void defon_trig_activate(struct led_classdev *led_cdev) { - __led_set_brightness(led_cdev, led_cdev->max_brightness); + led_set_brightness_async(led_cdev, led_cdev->max_brightness); } static struct led_trigger defon_led_trigger = { diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c index c86c41826476..4cc7040746c6 100644 --- a/drivers/leds/trigger/ledtrig-gpio.c +++ b/drivers/leds/trigger/ledtrig-gpio.c @@ -54,12 +54,12 @@ static void gpio_trig_work(struct work_struct *work) if (tmp) { if (gpio_data->desired_brightness) - __led_set_brightness(gpio_data->led, + led_set_brightness_async(gpio_data->led, gpio_data->desired_brightness); else - __led_set_brightness(gpio_data->led, LED_FULL); + led_set_brightness_async(gpio_data->led, LED_FULL); } else { - __led_set_brightness(gpio_data->led, LED_OFF); + led_set_brightness_async(gpio_data->led, LED_OFF); } } diff --git a/drivers/leds/trigger/ledtrig-heartbeat.c b/drivers/leds/trigger/ledtrig-heartbeat.c index 5c8464a33172..fea6871d2609 100644 --- a/drivers/leds/trigger/ledtrig-heartbeat.c +++ b/drivers/leds/trigger/ledtrig-heartbeat.c @@ -74,7 +74,7 @@ static void led_heartbeat_function(unsigned long data) break; } - __led_set_brightness(led_cdev, brightness); + led_set_brightness_async(led_cdev, brightness); mod_timer(&heartbeat_data->timer, jiffies + delay); } diff --git a/drivers/leds/trigger/ledtrig-oneshot.c b/drivers/leds/trigger/ledtrig-oneshot.c index cb4c7466692a..fbd02cdc3ad7 100644 --- a/drivers/leds/trigger/ledtrig-oneshot.c +++ b/drivers/leds/trigger/ledtrig-oneshot.c @@ -63,9 +63,9 @@ static ssize_t led_invert_store(struct device *dev, oneshot_data->invert = !!state; if (oneshot_data->invert) - __led_set_brightness(led_cdev, LED_FULL); + led_set_brightness_async(led_cdev, LED_FULL); else - __led_set_brightness(led_cdev, LED_OFF); + led_set_brightness_async(led_cdev, LED_OFF); return size; } diff --git a/drivers/leds/trigger/ledtrig-transient.c b/drivers/leds/trigger/ledtrig-transient.c index e5abc00bb00c..3c34de404d18 100644 --- a/drivers/leds/trigger/ledtrig-transient.c +++ b/drivers/leds/trigger/ledtrig-transient.c @@ -41,7 +41,7 @@ static void transient_timer_function(unsigned long data) struct transient_trig_data *transient_data = led_cdev->trigger_data; transient_data->activate = 0; - __led_set_brightness(led_cdev, transient_data->restore_state); + led_set_brightness_async(led_cdev, transient_data->restore_state); } static ssize_t transient_activate_show(struct device *dev, @@ -72,7 +72,8 @@ static ssize_t transient_activate_store(struct device *dev, if (state == 0 && transient_data->activate == 1) { del_timer(&transient_data->timer); transient_data->activate = state; - __led_set_brightness(led_cdev, transient_data->restore_state); + led_set_brightness_async(led_cdev, + transient_data->restore_state); return size; } @@ -80,7 +81,7 @@ static ssize_t transient_activate_store(struct device *dev, if (state == 1 && transient_data->activate == 0 && transient_data->duration != 0) { transient_data->activate = state; - __led_set_brightness(led_cdev, transient_data->state); + led_set_brightness_async(led_cdev, transient_data->state); transient_data->restore_state = (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL; mod_timer(&transient_data->timer, @@ -203,7 +204,8 @@ static void transient_trig_deactivate(struct led_classdev *led_cdev) if (led_cdev->activated) { del_timer_sync(&transient_data->timer); - __led_set_brightness(led_cdev, transient_data->restore_state); + led_set_brightness_async(led_cdev, + transient_data->restore_state); device_remove_file(led_cdev->dev, &dev_attr_activate); device_remove_file(led_cdev->dev, &dev_attr_duration); device_remove_file(led_cdev->dev, &dev_attr_state); diff --git a/include/linux/leds.h b/include/linux/leds.h index 737f9b1051f2..dfe70e928eae 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -44,11 +44,19 @@ struct led_classdev { #define LED_BLINK_ONESHOT_STOP (1 << 18) #define LED_BLINK_INVERT (1 << 19) #define LED_SYSFS_DISABLE (1 << 20) +#define SET_BRIGHTNESS_ASYNC (1 << 21) +#define SET_BRIGHTNESS_SYNC (1 << 22) /* Set LED brightness level */ /* Must not sleep, use a workqueue if needed */ void (*brightness_set)(struct led_classdev *led_cdev, enum led_brightness brightness); + /* + * Set LED brightness level immediately - it can block the caller for + * the time required for accessing a LED device register. + */ + int (*brightness_set_sync)(struct led_classdev *led_cdev, + enum led_brightness brightness); /* Get LED brightness level */ enum led_brightness (*brightness_get)(struct led_classdev *led_cdev); -- cgit v1.2.3