[PATCH v3 5/5] drm: rcar-du: dsi: Fix VCLKSET write

[Tomi Valkeinen]

From: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>

rcar_mipi_dsi_startup() writes correct values to VCLKSET, but as it uses
or-operation to add the new values to the current value in the register,
it should first make sure the fields are cleared.

Do this by using rcar_mipi_dsi_write() to write the VCLKSET_CKEN bit to
VCLKSET before the rest of the VCLKSET configuration.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>
---
 drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
index 06250f2f3499..b60a6d4a5d46 100644
--- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
+++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
@@ -412,9 +412,10 @@ static int rcar_mipi_dsi_startup(struct rcar_mipi_dsi *dsi,
 			return ret;
 	}
 
-	/* Enable DOT clock */
-	vclkset = VCLKSET_CKEN;
-	rcar_mipi_dsi_set(dsi, VCLKSET, vclkset);
+	/* Clear VCLKSET and enable DOT clock */
+	rcar_mipi_dsi_write(dsi, VCLKSET, VCLKSET_CKEN);
+
+	vclkset = 0;
 
 	if (dsi_format == 24)
 		vclkset |= VCLKSET_BPP_24;
-- 
2.34.1