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 <j.anaszewski@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
---
drivers/leds/led-class.c | 10 ++++++----
drivers/leds/led-core.c | 19 ++++++++++++++++---
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, 63 insertions(+), 26 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 65722de..dbeebac 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 be6d9fa..a745e32 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 +126,18 @@ 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 4c50365..2348dbd 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -17,16 +17,28 @@
#include <linux/rwsem.h>
#include <linux/leds.h>
-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 47e55aa..59eca17 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 81a91be..6f38f88 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 c86c418..4cc7040 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 5c8464a..fea6871 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 cb4c746..fbd02cd 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 e5abc00..3c34de4 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 3737a5a..cfceef3 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);
--
1.7.9.5
--
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