[PATCH v3, 4/4] drm/mediatek: Add pull-down MIPI operation in mtk_dsi_poweroff function

[xinlei.lee at mediatek.com]

From: Xinlei Lee <xinlei.lee at mediatek.com>

In the dsi_enable function, mtk_dsi_rxtx_control is to
pull up the MIPI signal operation. Before dsi_disable,
MIPI should also be pulled down by writing a register instead of disabling dsi.

Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
Signed-off-by: Xinlei Lee <xinlei.lee at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index b509d59235e2..1c6a75a46b67 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -676,6 +676,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
+	/* set the lane number as 0 */
+	writel(0, dsi->regs + DSI_TXRX_CTRL);
 
 	mtk_dsi_disable(dsi);
 
-- 
2.18.0