drm/mediatek: add connection from RDMA2 to DSI3

This patch add the connection from RDMA2 to DSI3
Signed-off-by: Stu Hsieh <stu.hsieh@mediatek.com>
Signed-off-by: CK Hu <ck.hu@mediatek.com>

drivers/gpu/drm/mediatek/mtk_drm_ddp.c

@@ -96,6 +96,7 @@
 #define RDMA2_SOUT_DPI1			0x3
 #define RDMA2_SOUT_DSI1			0x1
 #define RDMA2_SOUT_DSI2			0x4
+#define RDMA2_SOUT_DSI3			0x5
 #define DPI0_SEL_IN_RDMA1		0x1
 #define DPI0_SEL_IN_RDMA2		0x3
 #define DPI1_SEL_IN_RDMA1		(0x1 << 8)
@@ -105,6 +106,7 @@
 #define DSI2_SEL_IN_RDMA1		(0x1 << 16)
 #define DSI2_SEL_IN_RDMA2		(0x4 << 16)
 #define DSI3_SEL_IN_RDMA1		(0x1 << 16)
+#define DSI3_SEL_IN_RDMA2		(0x4 << 16)
 #define COLOR1_SEL_IN_OVL1		0x1
 
 #define OVL_MOUT_EN_RDMA		0x1
@@ -214,6 +216,9 @@ static unsigned int mtk_ddp_mout_en(enum mtk_ddp_comp_id cur,
 	} else if (cur == DDP_COMPONENT_RDMA2 && next == DDP_COMPONENT_DSI2) {
 		*addr = DISP_REG_CONFIG_DISP_RDMA2_SOUT;
 		value = RDMA2_SOUT_DSI2;
+	} else if (cur == DDP_COMPONENT_RDMA2 && next == DDP_COMPONENT_DSI3) {
+		*addr = DISP_REG_CONFIG_DISP_RDMA2_SOUT;
+		value = RDMA2_SOUT_DSI3;
 	} else {
 		value = 0;
 	}
@@ -257,6 +262,9 @@ static unsigned int mtk_ddp_sel_in(enum mtk_ddp_comp_id cur,
 	} else if (cur == DDP_COMPONENT_RDMA2 && next == DDP_COMPONENT_DSI2) {
 		*addr = DISP_REG_CONFIG_DSIE_SEL_IN;
 		value = DSI2_SEL_IN_RDMA2;
+	} else if (cur == DDP_COMPONENT_RDMA2 && next == DDP_COMPONENT_DSI3) {
+		*addr = DISP_REG_CONFIG_DSIE_SEL_IN;
+		value = DSI3_SEL_IN_RDMA2;
 	} else if (cur == DDP_COMPONENT_OVL1 && next == DDP_COMPONENT_COLOR1) {
 		*addr = DISP_REG_CONFIG_DISP_COLOR1_SEL_IN;
 		value = COLOR1_SEL_IN_OVL1;