backlight: Backlight Class Improvements

index 151fda8..334b1db 100644
@@ -16,14 +16,12 @@
 
 static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
 {
-	int rc;
+	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
 	down(&bd->sem);
-	if (likely(bd->props && bd->props->get_power))
-		rc = sprintf(buf, "%d\n", bd->props->get_power(bd));
-	else
-		rc = -ENXIO;
+	if (likely(bd->props))
+		rc = sprintf(buf, "%d\n", bd->props->power);
 	up(&bd->sem);
 
 	return rc;

@@ -31,7 +29,7 @@ static ssize_t backlight_show_power(stru
 
 static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count)
 {
-	int rc, power;
+	int rc = -ENXIO, power;
 	char *endp;
 	struct backlight_device *bd = to_backlight_device(cdev);
 

@@ -40,12 +38,13 @@ static ssize_t backlight_store_power(str
 		return -EINVAL;
 
 	down(&bd->sem);
-	if (likely(bd->props && bd->props->set_power)) {
+	if (likely(bd->props)) {
 		pr_debug("backlight: set power to %d\n", power);
-		bd->props->set_power(bd, power);
+		bd->props->power = power;
+		if (likely(bd->props->update_status))
+			bd->props->update_status(bd);
 		rc = count;
-	} else
-		rc = -ENXIO;
+	}
 	up(&bd->sem);
 
 	return rc;

@@ -53,14 +52,12 @@ static ssize_t backlight_store_power(str
 
 static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
 {
-	int rc;
+	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
 	down(&bd->sem);
-	if (likely(bd->props && bd->props->get_brightness))
-		rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
-	else
-		rc = -ENXIO;
+	if (likely(bd->props))
+		rc = sprintf(buf, "%d\n", bd->props->brightness);
 	up(&bd->sem);
 
 	return rc;

@@ -68,7 +65,7 @@ static ssize_t backlight_show_brightness
 
 static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count)
 {
-	int rc, brightness;
+	int rc = -ENXIO, brightness;
 	char *endp;
 	struct backlight_device *bd = to_backlight_device(cdev);
 

@@ -77,12 +74,18 @@ static ssize_t backlight_store_brightnes
 		return -EINVAL;
 
 	down(&bd->sem);
-	if (likely(bd->props && bd->props->set_brightness)) {
-		pr_debug("backlight: set brightness to %d\n", brightness);
-		bd->props->set_brightness(bd, brightness);
-		rc = count;
-	} else
-		rc = -ENXIO;
+	if (likely(bd->props)) {
+		if (brightness > bd->props->max_brightness)
+			rc = -EINVAL;
+		else {
+			pr_debug("backlight: set brightness to %d\n",
+				 brightness);
+			bd->props->brightness = brightness;
+			if (likely(bd->props->update_status))
+				bd->props->update_status(bd);
+			rc = count;
+		}
+	}
 	up(&bd->sem);
 
 	return rc;

@@ -90,14 +93,26 @@ static ssize_t backlight_store_brightnes
 
 static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf)
 {
-	int rc;
+	int rc = -ENXIO;
 	struct backlight_device *bd = to_backlight_device(cdev);
 
 	down(&bd->sem);
 	if (likely(bd->props))
 		rc = sprintf(buf, "%d\n", bd->props->max_brightness);
-	else
-		rc = -ENXIO;
+	up(&bd->sem);
+
+	return rc;
+}
+
+static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
+						char *buf)
+{
+	int rc = -ENXIO;
+	struct backlight_device *bd = to_backlight_device(cdev);
+
+	down(&bd->sem);
+	if (likely(bd->props && bd->props->get_brightness))
+		rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
 	up(&bd->sem);
 
 	return rc;

@@ -123,7 +138,10 @@ static struct class backlight_class = {
 
 static struct class_device_attribute bl_class_device_attributes[] = {
 	DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
-	DECLARE_ATTR(brightness, 0644, backlight_show_brightness, backlight_store_brightness),
+	DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
+		     backlight_store_brightness),
+	DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
+		     NULL),
 	DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
 };
 

@@ -144,8 +162,12 @@ static int fb_notifier_callback(struct n
 	bd = container_of(self, struct backlight_device, fb_notif);
 	down(&bd->sem);
 	if (bd->props)
-		if (!bd->props->check_fb || bd->props->check_fb(evdata->info))
-			bd->props->set_power(bd, *(int *)evdata->data);
+		if (!bd->props->check_fb ||
+		    bd->props->check_fb(evdata->info)) {
+			bd->props->fb_blank = *(int *)evdata->data;
+			if (likely(bd->props && bd->props->update_status))
+				bd->props->update_status(bd);
+		}
 	up(&bd->sem);
 	return 0;
 }

@@ -231,6 +253,12 @@ void backlight_device_unregister(struct 
 					 &bl_class_device_attributes[i]);
 
 	down(&bd->sem);
+	if (likely(bd->props && bd->props->update_status)) {
+		bd->props->brightness = 0;
+		bd->props->power = 0;
+		bd->props->update_status(bd);
+	}
+
 	bd->props = NULL;
 	up(&bd->sem);
 

175 lines not on this page · raw message

index bb9e543..75e91f5 100644
@@ -19,20 +19,25 @@ struct fb_info;
 struct backlight_properties {
 	/* Owner module */
 	struct module *owner;
-	/* Get the backlight power status (0: full on, 1..3: power saving
-	   modes; 4: full off), see FB_BLANK_XXX */
-	int (*get_power)(struct backlight_device *);
-	/* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
-	int (*set_power)(struct backlight_device *, int power);
-	/* Maximal value for brightness (read-only) */
-	int max_brightness;
-	/* Get current backlight brightness */
+
+	/* Notify the backlight driver some property has changed */
+	int (*update_status)(struct backlight_device *);
+	/* Return the current backlight brightness (accounting for power,
+	   fb_blank etc.) */
 	int (*get_brightness)(struct backlight_device *);
-	/* Set backlight brightness (0..max_brightness) */
-	int (*set_brightness)(struct backlight_device *, int brightness);
 	/* Check if given framebuffer device is the one bound to this backlight;
 	   return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
 	int (*check_fb)(struct fb_info *);
+
+	/* Current User requested brightness (0 - max_brightness) */
+	int brightness;
+	/* Maximal value for brightness (read-only) */
+	int max_brightness;
+	/* Current FB Power mode (0: full on, 1..3: power saving
+	   modes; 4: full off), see FB_BLANK_XXX */
+	int power;
+	/* FB Blanking active? (values as for power) */
+	int fb_blank;
 };
 
 struct backlight_device {