diff mbox

[v2,1/3] drm: rcar-du: lvds: Fix LVDS startup on R-Car Gen2

Message ID 20180214181348.16258-2-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State Not Applicable
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Laurent Pinchart Feb. 14, 2018, 6:13 p.m. UTC 
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

According to the latest revision 2.00 of the R-Car Gen2 manual, the LVDS
and the bias circuit must be enabled after the LVDS I/O pins are
enabled, not before. Fix the Gen2 LVDS startup sequence accordingly.

While at it, also fix the comment preceding the first LVDCR0 write that
still talks about hardcoding the LVDS mode 0.

Fixes: 90374b5c25c9 ("drm/rcar-du: Add internal LVDS encoder support")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
diff mbox

Patch

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
index abbb7b25129a..dcffd3b59b69 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
@@ -59,11 +59,8 @@  static void rcar_du_lvdsenc_start_gen2(struct rcar_du_lvdsenc *lvds,
 
 	rcar_lvds_write(lvds, LVDPLLCR, pllcr);
 
-	/*
-	 * Select the input, hardcode mode 0, enable LVDS operation and turn
-	 * bias circuitry on.
-	 */
-	lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_BEN | LVDCR0_LVEN;
+	/* Select the input and set the LVDS mode. */
+	lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;
 	if (rcrtc->index == 2)
 		lvdcr0 |= LVDCR0_DUSEL;
 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
@@ -73,6 +70,10 @@  static void rcar_du_lvdsenc_start_gen2(struct rcar_du_lvdsenc *lvds,
 			LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
 			LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
 
+	/* Enable LVDS operation and turn bias circuitry on. */
+	lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN;
+	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
 	/*
 	 * Turn the PLL on, wait for the startup delay, and turn the output
 	 * on.