drm/mediatek: Refactor plane init

Add a couple of functions which enumerate the number of planes for a
component and initialize the planes for a component.

No functional changes in this patch, but it will allow us to selectively
support rotation if the component supports it.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -543,14 +543,63 @@ void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *comp)
 	mtk_drm_finish_page_flip(mtk_crtc);
 }
 
+static int mtk_drm_crtc_num_comp_planes(struct mtk_drm_crtc *mtk_crtc,
+					int comp_idx)
+{
+	struct mtk_ddp_comp *comp;
+
+	if (comp_idx > 1)
+		return 0;
+
+	comp = mtk_crtc->ddp_comp[comp_idx];
+	if (!comp->funcs)
+		return 0;
+
+	if (comp_idx == 1 && !comp->funcs->bgclr_in_on)
+		return 0;
+
+	return mtk_ddp_comp_layer_nr(comp);
+}
+
+static inline
+enum drm_plane_type mtk_drm_crtc_plane_type(unsigned int plane_idx)
+{
+	if (plane_idx == 0)
+		return DRM_PLANE_TYPE_PRIMARY;
+	else if (plane_idx == 1)
+		return DRM_PLANE_TYPE_CURSOR;
+	else
+		return DRM_PLANE_TYPE_OVERLAY;
+
+}
+
+static int mtk_drm_crtc_init_comp_planes(struct drm_device *drm_dev,
+					 struct mtk_drm_crtc *mtk_crtc,
+					 int comp_idx, int pipe)
+{
+	int num_planes = mtk_drm_crtc_num_comp_planes(mtk_crtc, comp_idx);
+	int i, ret;
+
+	for (i = 0; i < num_planes; i++) {
+		ret = mtk_plane_init(drm_dev,
+				&mtk_crtc->planes[mtk_crtc->layer_nr],
+				BIT(pipe),
+				mtk_drm_crtc_plane_type(mtk_crtc->layer_nr));
+		if (ret)
+			return ret;
+
+		mtk_crtc->layer_nr++;
+	}
+	return 0;
+}
+
 int mtk_drm_crtc_create(struct drm_device *drm_dev,
 			const enum mtk_ddp_comp_id *path, unsigned int path_len)
 {
 	struct mtk_drm_private *priv = drm_dev->dev_private;
 	struct device *dev = drm_dev->dev;
 	struct mtk_drm_crtc *mtk_crtc;
-	enum drm_plane_type type;
-	unsigned int zpos;
+	unsigned int num_comp_planes = 0;
 	int pipe = priv->num_pipes;
 	int ret;
 	int i;
@@ -606,23 +655,15 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		mtk_crtc->ddp_comp[i] = comp;
 	}
 
-	mtk_crtc->layer_nr = mtk_ddp_comp_layer_nr(mtk_crtc->ddp_comp[0]);
-	if (mtk_crtc->ddp_comp_nr > 1) {
-		struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[1];
+	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
+		num_comp_planes += mtk_drm_crtc_num_comp_planes(mtk_crtc, i);
 
-		if (comp->funcs->bgclr_in_on)
-			mtk_crtc->layer_nr += mtk_ddp_comp_layer_nr(comp);
-	}
-	mtk_crtc->planes = devm_kcalloc(dev, mtk_crtc->layer_nr,
-					sizeof(struct drm_plane),
-					GFP_KERNEL);
+	mtk_crtc->planes = devm_kcalloc(dev, num_comp_planes,
+					sizeof(struct drm_plane), GFP_KERNEL);
 
-	for (zpos = 0; zpos < mtk_crtc->layer_nr; zpos++) {
-		type = (zpos == 0) ? DRM_PLANE_TYPE_PRIMARY :
-				(zpos == 1) ? DRM_PLANE_TYPE_CURSOR :
-						DRM_PLANE_TYPE_OVERLAY;
-		ret = mtk_plane_init(drm_dev, &mtk_crtc->planes[zpos],
-				     BIT(pipe), type);
+	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
+		ret = mtk_drm_crtc_init_comp_planes(drm_dev, mtk_crtc, i,
+						    pipe);
 		if (ret)
 			return ret;
 	}