drm/mediatek: adjust ddp clock control flow

display hardware clock will not unprepare when
crtc is disable, until crtc is destroyed.
with this patch, hard clock will disable and unprepare
at the same time.
Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_crtc.c

@@ -98,10 +98,6 @@ static void mtk_drm_finish_page_flip(struct mtk_drm_crtc *mtk_crtc)
 static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
 {
 	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
-	int i;
-
-	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
-		clk_unprepare(mtk_crtc->ddp_comp[i]->clk);
 
 	mtk_disp_mutex_put(mtk_crtc->mutex);
 
@@ -194,7 +190,7 @@ static int mtk_crtc_ddp_clk_enable(struct mtk_drm_crtc *mtk_crtc)
 
 	DRM_DEBUG_DRIVER("%s\n", __func__);
 	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
-		ret = clk_enable(mtk_crtc->ddp_comp[i]->clk);
+		ret = clk_prepare_enable(mtk_crtc->ddp_comp[i]->clk);
 		if (ret) {
 			DRM_ERROR("Failed to enable clock %d: %d\n", i, ret);
 			goto err;
@@ -204,7 +200,7 @@ static int mtk_crtc_ddp_clk_enable(struct mtk_drm_crtc *mtk_crtc)
 	return 0;
 err:
 	while (--i >= 0)
-		clk_disable(mtk_crtc->ddp_comp[i]->clk);
+		clk_disable_unprepare(mtk_crtc->ddp_comp[i]->clk);
 	return ret;
 }
 
@@ -214,7 +210,7 @@ static void mtk_crtc_ddp_clk_disable(struct mtk_drm_crtc *mtk_crtc)
 
 	DRM_DEBUG_DRIVER("%s\n", __func__);
 	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
-		clk_disable(mtk_crtc->ddp_comp[i]->clk);
+		clk_disable_unprepare(mtk_crtc->ddp_comp[i]->clk);
 }
 
 static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
@@ -585,15 +581,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		if (!comp) {
 			dev_err(dev, "Component %pOF not initialized\n", node);
 			ret = -ENODEV;
-			goto unprepare;
-		}
-
-		ret = clk_prepare(comp->clk);
-		if (ret) {
-			dev_err(dev,
-				"Failed to prepare clock for component %pOF: %d\n",
-				node, ret);
-			goto unprepare;
+			return ret;
 		}
 
 		mtk_crtc->ddp_comp[i] = comp;
@@ -611,23 +599,17 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		ret = mtk_plane_init(drm_dev, &mtk_crtc->planes[zpos],
 				     BIT(pipe), type);
 		if (ret)
-			goto unprepare;
+			return ret;
 	}
 
 	ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
 				mtk_crtc->layer_nr > 1 ? &mtk_crtc->planes[1] :
 				NULL, pipe);
 	if (ret < 0)
-		goto unprepare;
+		return ret;
 	drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
 	drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, false, MTK_LUT_SIZE);
 	priv->num_pipes++;
 
 	return 0;
-
-unprepare:
-	while (--i >= 0)
-		clk_unprepare(mtk_crtc->ddp_comp[i]->clk);
-
-	return ret;
 }