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| author | Guennadi Liakhovetski <lg@denx.de> | 2009-01-10 21:54:39 +0300 |
|---|---|---|
| committer | Richard Purdie <rpurdie@linux.intel.com> | 2009-04-06 19:06:25 +0400 |
| commit | 1bd465e6b0e2b559db47420fea686507a01cfab0 (patch) | |
| tree | 623c7a906e4ce117873a33f5b1717e150d5f9e59 /drivers/leds/led-class.c | |
| parent | a7d878af94b223013a48078e0c8c0a654c24a057 (diff) | |
| download | linux-1bd465e6b0e2b559db47420fea686507a01cfab0.tar.xz | |
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>
Diffstat (limited to 'drivers/leds/led-class.c')
| -rw-r--r-- | drivers/leds/led-class.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 52f82e3ea13a..f2cc13d76810 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -64,7 +64,16 @@ static ssize_t led_brightness_store(struct device *dev, 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 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) 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 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev) #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 @@ EXPORT_SYMBOL_GPL(led_classdev_register); */ 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); |