drm: rcar-du: Fix LVDS start sequence on Gen3

According to the latest revision of the datasheet, the LVDS I/O pins
must be enabled before starting the PLL. Fix it.

Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
index b74105a80a6e..e3a4985f6f3f 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
@@ -104,7 +104,14 @@ static void rcar_du_lvdsenc_start_gen3(struct rcar_du_lvdsenc *lvds,
 
         rcar_lvds_write(lvds, LVDPLLCR, pllcr);
 
-        /* Turn the PLL on, set it to LVDS normal mode, wait for the startup
+        /* Turn all the channels on. */
+        rcar_lvds_write(lvds, LVDCR1,
+                        LVDCR1_CHSTBY_GEN3(3) | LVDCR1_CHSTBY_GEN3(2) |
+                        LVDCR1_CHSTBY_GEN3(1) | LVDCR1_CHSTBY_GEN3(0) |
+                        LVDCR1_CLKSTBY_GEN3);
+
+        /*
+         * Turn the PLL on, set it to LVDS normal mode, wait for the startup
          * delay and turn the output on.
          */
         lvdcr0 = LVDCR0_PLLON;
@@ -117,12 +124,6 @@ static void rcar_du_lvdsenc_start_gen3(struct rcar_du_lvdsenc *lvds,
 
         lvdcr0 |= LVDCR0_LVRES;
         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
-
-        /* Turn all the channels on. */
-        rcar_lvds_write(lvds, LVDCR1,
-                        LVDCR1_CHSTBY_GEN3(3) | LVDCR1_CHSTBY_GEN3(2) |
-                        LVDCR1_CHSTBY_GEN3(1) | LVDCR1_CHSTBY_GEN3(0) |
-                        LVDCR1_CLKSTBY_GEN3);
 }
 
 static int rcar_du_lvdsenc_start(struct rcar_du_lvdsenc *lvds,