1 files changed, 57 insertions, 4 deletions

diff --git a/drivers/leds/ledtrig-backlight.c b/drivers/leds/ledtrig-backlight.c
index f948e57bd9b8..2b513a2ad7de 100644
--- a/drivers/leds/ledtrig-backlight.c
+++ b/drivers/leds/ledtrig-backlight.c
@@ -26,6 +26,7 @@ struct bl_trig_notifier {
         int brightness;
         int old_status;
         struct notifier_block notifier;
+        unsigned invert;
 };
 
 static int fb_notifier_callback(struct notifier_block *p,
@@ -36,23 +37,64 @@ static int fb_notifier_callback(struct notifier_block *p,
         struct led_classdev *led = n->led;
         struct fb_event *fb_event = data;
         int *blank = fb_event->data;
+        int new_status = *blank ? BLANK : UNBLANK;
 
         switch (event) {
         case FB_EVENT_BLANK :
-                if (*blank && n->old_status == UNBLANK) {
+                if (new_status == n->old_status)
+                        break;
+
+                if ((n->old_status == UNBLANK) ^ n->invert) {
                         n->brightness = led->brightness;
                         led_set_brightness(led, LED_OFF);
-                        n->old_status = BLANK;
-                } else if (!*blank && n->old_status == BLANK) {
+                } else {
                         led_set_brightness(led, n->brightness);
-                        n->old_status = UNBLANK;
                 }
+
+                n->old_status = new_status;
+
                 break;
         }
 
         return 0;
 }
 
+static ssize_t bl_trig_invert_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct led_classdev *led = dev_get_drvdata(dev);
+        struct bl_trig_notifier *n = led->trigger_data;
+
+        return sprintf(buf, "%u\n", n->invert);
+}
+
+static ssize_t bl_trig_invert_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t num)
+{
+        struct led_classdev *led = dev_get_drvdata(dev);
+        struct bl_trig_notifier *n = led->trigger_data;
+        unsigned long invert;
+        int ret;
+
+        ret = strict_strtoul(buf, 10, &invert);
+        if (ret < 0)
+                return ret;
+
+        if (invert > 1)
+                return -EINVAL;
+
+        n->invert = invert;
+
+        /* After inverting, we need to update the LED. */
+        if ((n->old_status == BLANK) ^ n->invert)
+                led_set_brightness(led, LED_OFF);
+        else
+                led_set_brightness(led, n->brightness);
+
+        return num;
+}
+static DEVICE_ATTR(inverted, 0644, bl_trig_invert_show, bl_trig_invert_store);
+
 static void bl_trig_activate(struct led_classdev *led)
 {
         int ret;
@@ -66,6 +108,10 @@ static void bl_trig_activate(struct led_classdev *led)
                 return;
         }
 
+        ret = device_create_file(led->dev, &dev_attr_inverted);
+        if (ret)
+                goto err_invert;
+
         n->led = led;
         n->brightness = led->brightness;
         n->old_status = UNBLANK;
@@ -74,6 +120,12 @@ static void bl_trig_activate(struct led_classdev *led)
         ret = fb_register_client(&n->notifier);
         if (ret)
                 dev_err(led->dev, "unable to register backlight trigger\n");
+
+        return;
+
+err_invert:
+        led->trigger_data = NULL;
+        kfree(n);
 }
 
 static void bl_trig_deactivate(struct led_classdev *led)
@@ -82,6 +134,7 @@ static void bl_trig_deactivate(struct led_classdev *led)
                 (struct bl_trig_notifier *) led->trigger_data;
 
         if (n) {
+                device_remove_file(led->dev, &dev_attr_inverted);
                 fb_unregister_client(&n->notifier);
                 kfree(n);
         }