drm/rcar-du: Add LVDS_LANES quirk

LVDS lanes 1 and 3 are switched in ES1 hardware (R8A7790). The problem
has been fixed in newer revisions, add a quirk to make the workaround
selectable.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

3 files changed, 12 insertions, 6 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index a0ffacb4b80b..4eee02f89965 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -250,7 +250,7 @@ static const struct rcar_du_device_info rcar_du_r8a7779_info = {
 
 static const struct rcar_du_device_info rcar_du_r8a7790_info = {
         .features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK | RCAR_DU_FEATURE_DEFR8,
-        .quirks = RCAR_DU_QUIRK_ALIGN_128B,
+        .quirks = RCAR_DU_QUIRK_ALIGN_128B | RCAR_DU_QUIRK_LVDS_LANES,
         .num_crtcs = 3,
         .routes = {
                 /* R8A7790 has one RGB output, two LVDS outputs and one
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.h b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
index 7ca98f352479..e31b735d3f25 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
@@ -31,6 +31,7 @@ struct rcar_du_lvdsenc;
 #define RCAR_DU_FEATURE_DEFR8           (1 << 1)        /* Has DEFR8 register */
 
 #define RCAR_DU_QUIRK_ALIGN_128B        (1 << 0)        /* Align pitches to 128 bytes */
+#define RCAR_DU_QUIRK_LVDS_LANES        (1 << 1)        /* LVDS lanes 1 and 3 inverted */
 
 /*
  * struct rcar_du_output_routing - Output routing specification
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
index fe1f6f59f539..df30a075d793 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c
@@ -44,6 +44,7 @@ static int rcar_du_lvdsenc_start(struct rcar_du_lvdsenc *lvds,
         const struct drm_display_mode *mode = &rcrtc->crtc.mode;
         unsigned int freq = mode->clock;
         u32 lvdcr0;
+        u32 lvdhcr;
         u32 pllcr;
         int ret;
 
@@ -72,15 +73,19 @@ static int rcar_du_lvdsenc_start(struct rcar_du_lvdsenc *lvds,
          * VSYNC -> CTRL1
          * DISP  -> CTRL2
          * 0     -> CTRL3
-         *
-         * Channels 1 and 3 are switched on ES1.
          */
         rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
                         LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
                         LVDCTRCR_CTR0SEL_HSYNC);
-        rcar_lvds_write(lvds, LVDCHCR,
-                        LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3) |
-                        LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1));
+
+        if (rcar_du_needs(lvds->dev, RCAR_DU_QUIRK_LVDS_LANES))
+                lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3)
+                       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1);
+        else
+                lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 1)
+                       | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 3);
+
+        rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
 
         /* Select the input, hardcode mode 0, enable LVDS operation and turn
          * bias circuitry on.