fbdev: omapfb: panel-dsi-cm: Use backlight helper

Instead of retrieving the backlight brightness in struct
backlight_properties manually, and then checking whether the backlight
should be on at all, use backlight_get_brightness() which does all
this and insulates this from future changes.
Signed-off-by: Stephen Kitt <steve@sk2.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-omap@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/omap2/omapfb/displays/panel-dsi-cm.c

@@ -331,13 +331,7 @@ static int dsicm_bl_update_status(struct backlight_device *dev)
 	struct panel_drv_data *ddata = dev_get_drvdata(&dev->dev);
 	struct omap_dss_device *in = ddata->in;
 	int r;
-	int level;
-
-	if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
-			dev->props.power == FB_BLANK_UNBLANK)
-		level = dev->props.brightness;
-	else
-		level = 0;
+	int level = backlight_get_brightness(dev);
 
 	dev_dbg(&ddata->pdev->dev, "update brightness to %d\n", level);