backlight: Allow properties to be passed at registration

Values such as max_brightness should be set before backlights are
registered, but the current API doesn't allow that. Add a parameter to
backlight_device_register and update drivers to ensure that they
set this correctly.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 20564f8..406228f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -89,19 +89,21 @@
 
 static int nouveau_nv40_backlight_init(struct drm_device *dev)
 {
+	struct backlight_properties props;
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct backlight_device *bd;
 
 	if (!(nv_rd32(dev, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
 		return 0;
 
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = 31;
 	bd = backlight_device_register("nv_backlight", &dev->pdev->dev, dev,
-				       &nv40_bl_ops);
+				       &nv40_bl_ops, &props);
 	if (IS_ERR(bd))
 		return PTR_ERR(bd);
 
 	dev_priv->backlight = bd;
-	bd->props.max_brightness = 31;
 	bd->props.brightness = nv40_get_intensity(bd);
 	backlight_update_status(bd);
 
@@ -110,19 +112,21 @@
 
 static int nouveau_nv50_backlight_init(struct drm_device *dev)
 {
+	struct backlight_properties props;
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct backlight_device *bd;
 
 	if (!nv_rd32(dev, NV50_PDISPLAY_SOR_BACKLIGHT))
 		return 0;
 
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = 1025;
 	bd = backlight_device_register("nv_backlight", &dev->pdev->dev, dev,
-				       &nv50_bl_ops);
+				       &nv50_bl_ops, &props);
 	if (IS_ERR(bd))
 		return PTR_ERR(bd);
 
 	dev_priv->backlight = bd;
-	bd->props.max_brightness = 1025;
 	bd->props.brightness = nv50_get_intensity(bd);
 	backlight_update_status(bd);
 	return 0;