drm/bridge/synopsys: dsi: allow LP commands in video mode

Current code only sends LP commands in command mode.

Allows sending LP commands also in video mode by setting the
proper flag in DSI_VID_MODE_CFG.
Signed-off-by: Antonio Borneo <antonio.borneo@st.com>
Tested-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200708140836.32418-1-yannick.fertre@st.com

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -89,6 +89,7 @@
 #define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS	0x1
 #define VID_MODE_TYPE_BURST			0x2
 #define VID_MODE_TYPE_MASK			0x3
+#define ENABLE_LOW_POWER_CMD		BIT(15)
 #define VID_MODE_VPG_ENABLE		BIT(16)
 #define VID_MODE_VPG_HORIZONTAL		BIT(24)
 
@@ -367,6 +368,13 @@ static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
 
 	dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
 	dsi_write(dsi, DSI_CMD_MODE_CFG, val);
+
+	val = dsi_read(dsi, DSI_VID_MODE_CFG);
+	if (lpm)
+		val |= ENABLE_LOW_POWER_CMD;
+	else
+		val &= ~ENABLE_LOW_POWER_CMD;
+	dsi_write(dsi, DSI_VID_MODE_CFG, val);
 }
 
 static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)