From 8525d04ba8a6a9ecfa4bd619c988ca873a5fc2a4 Mon Sep 17 00:00:00 2001
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Date: Fri, 12 Jan 2018 23:12:05 +0300
Subject: [PATCH] drm: rcar-du: lvds: Fix LVDS startup on R-Car Gen2
Git-commit: 8525d04ba8a6a9ecfa4bd619c988ca873a5fc2a4
Patch-mainline: v4.17-rc1
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- 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(s
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(s
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.