drm/mediatek: Start/Stop components with function pointers

By registering component related functions to the pointers,
we can easily manage them within a for-loop and simplify the
logic of component start/stop process.

Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20231214055847.4936-16-shawn.sung@mediatek.com/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

Author: Hsiao Chien Sung

drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c

@@ -72,6 +72,8 @@ static const char * const private_comp_stem[OVL_ADAPTOR_TYPE_NUM] = {
 static const struct mtk_ddp_comp_funcs ethdr = {
 	.clk_enable = mtk_ethdr_clk_enable,
 	.clk_disable = mtk_ethdr_clk_disable,
+	.start = mtk_ethdr_start,
+	.stop = mtk_ethdr_stop,
 };
 
 static const struct mtk_ddp_comp_funcs merge = {
@@ -191,16 +193,30 @@ void mtk_ovl_adaptor_config(struct device *dev, unsigned int w,
 
 void mtk_ovl_adaptor_start(struct device *dev)
 {
+	int i;
 	struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
 
-	mtk_ethdr_start(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
+	for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
+		if (!ovl_adaptor->ovl_adaptor_comp[i] ||
+		    !comp_matches[i].funcs->start)
+			continue;
+
+		comp_matches[i].funcs->start(ovl_adaptor->ovl_adaptor_comp[i]);
+	}
 }
 
 void mtk_ovl_adaptor_stop(struct device *dev)
 {
+	int i;
 	struct mtk_disp_ovl_adaptor *ovl_adaptor = dev_get_drvdata(dev);
 
-	mtk_ethdr_stop(ovl_adaptor->ovl_adaptor_comp[OVL_ADAPTOR_ETHDR0]);
+	for (i = 0; i < OVL_ADAPTOR_ID_MAX; i++) {
+		if (!ovl_adaptor->ovl_adaptor_comp[i] ||
+		    !comp_matches[i].funcs->stop)
+			continue;
+
+		comp_matches[i].funcs->stop(ovl_adaptor->ovl_adaptor_comp[i]);
+	}
 }
 
 /**