leds: allow led-drivers to use a variable range of brightness values
This patch allows drivers to override the default maximum brightness value
of 255. We take care to preserve backwards-compatibility as much as
possible, so that user-space ABI doesn't change for existing drivers.
LED trigger code has also been updated to use the per-LED maximum.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 52f82e3..f2cc13d 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -64,7 +64,16 @@
return ret;
}
+static ssize_t led_max_brightness_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", led_cdev->max_brightness);
+}
+
static DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store);
+static DEVICE_ATTR(max_brightness, 0444, led_max_brightness_show, NULL);
#ifdef CONFIG_LEDS_TRIGGERS
static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
#endif
@@ -138,6 +147,13 @@
list_add_tail(&led_cdev->node, &leds_list);
up_write(&leds_list_lock);
+ if (!led_cdev->max_brightness)
+ led_cdev->max_brightness = LED_FULL;
+
+ rc = device_create_file(led_cdev->dev, &dev_attr_max_brightness);
+ if (rc)
+ goto err_out_attr_max;
+
led_update_brightness(led_cdev);
#ifdef CONFIG_LEDS_TRIGGERS
@@ -155,9 +171,11 @@
#ifdef CONFIG_LEDS_TRIGGERS
err_out_led_list:
+ device_remove_file(led_cdev->dev, &dev_attr_max_brightness);
+#endif
+err_out_attr_max:
device_remove_file(led_cdev->dev, &dev_attr_brightness);
list_del(&led_cdev->node);
-#endif
err_out:
device_unregister(led_cdev->dev);
return rc;
@@ -172,6 +190,7 @@
*/
void led_classdev_unregister(struct led_classdev *led_cdev)
{
+ device_remove_file(led_cdev->dev, &dev_attr_max_brightness);
device_remove_file(led_cdev->dev, &dev_attr_brightness);
#ifdef CONFIG_LEDS_TRIGGERS
device_remove_file(led_cdev->dev, &dev_attr_trigger);
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index 5edbf52..2dd8ecb 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -20,8 +20,8 @@
static inline void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness value)
{
- if (value > LED_FULL)
- value = LED_FULL;
+ if (value > led_cdev->max_brightness)
+ value = led_cdev->max_brightness;
led_cdev->brightness = value;
if (!(led_cdev->flags & LED_SUSPENDED))
led_cdev->brightness_set(led_cdev, value);
diff --git a/drivers/leds/ledtrig-default-on.c b/drivers/leds/ledtrig-default-on.c
index 92995e4..a4ef54b 100644
--- a/drivers/leds/ledtrig-default-on.c
+++ b/drivers/leds/ledtrig-default-on.c
@@ -19,7 +19,7 @@
static void defon_trig_activate(struct led_classdev *led_cdev)
{
- led_set_brightness(led_cdev, LED_FULL);
+ led_set_brightness(led_cdev, led_cdev->max_brightness);
}
static struct led_trigger defon_led_trigger = {
diff --git a/drivers/leds/ledtrig-heartbeat.c b/drivers/leds/ledtrig-heartbeat.c
index 4bf8cec..c1c1ea6 100644
--- a/drivers/leds/ledtrig-heartbeat.c
+++ b/drivers/leds/ledtrig-heartbeat.c
@@ -47,7 +47,7 @@
msecs_to_jiffies(heartbeat_data->period);
delay = msecs_to_jiffies(70);
heartbeat_data->phase++;
- brightness = LED_FULL;
+ brightness = led_cdev->max_brightness;
break;
case 1:
delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
@@ -56,7 +56,7 @@
case 2:
delay = msecs_to_jiffies(70);
heartbeat_data->phase++;
- brightness = LED_FULL;
+ brightness = led_cdev->max_brightness;
break;
default:
delay = heartbeat_data->period - heartbeat_data->period / 4 -
diff --git a/drivers/leds/ledtrig-ide-disk.c b/drivers/leds/ledtrig-ide-disk.c
index 883a577..ec099fc 100644
--- a/drivers/leds/ledtrig-ide-disk.c
+++ b/drivers/leds/ledtrig-ide-disk.c
@@ -37,7 +37,8 @@
{
if (ide_lastactivity != ide_activity) {
ide_lastactivity = ide_activity;
- led_trigger_event(ledtrig_ide, LED_FULL);
+ /* INT_MAX will set each LED to its maximum brightness */
+ led_trigger_event(ledtrig_ide, INT_MAX);
mod_timer(&ledtrig_ide_timer, jiffies + msecs_to_jiffies(10));
} else {
led_trigger_event(ledtrig_ide, LED_OFF);
diff --git a/drivers/leds/ledtrig-timer.c b/drivers/leds/ledtrig-timer.c
index 3d65313..3b83406 100644
--- a/drivers/leds/ledtrig-timer.c
+++ b/drivers/leds/ledtrig-timer.c
@@ -166,7 +166,7 @@
timer_data->brightness_on = led_get_brightness(led_cdev);
if (timer_data->brightness_on == LED_OFF)
- timer_data->brightness_on = LED_FULL;
+ timer_data->brightness_on = led_cdev->max_brightness;
led_cdev->trigger_data = timer_data;
init_timer(&timer_data->timer);