[PATCH 2/2] drm/sun4i: tcon: Support LVDS dual-link

[Maxime Ripard]

Some LVDS encoders in the Allwinner SoCs can output on a dual-link. Let's
add a DT property to toggle it.

Signed-off-by: Maxime Ripard <maxime at cerno.tech>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 6 ++++++
 drivers/gpu/drm/sun4i/sun4i_tcon.h | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index e616cc901b4e..ed1f09e52ef3 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -488,6 +488,9 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon,
 	else
 		reg |= SUN4I_TCON0_LVDS_IF_DATA_POL_NORMAL;
 
+	if (tcon->lvds_dual_link)
+		reg |= SUN4I_TCON0_LVDS_IF_DUAL_LINK;
+
 	if (sun4i_tcon_get_pixel_depth(encoder) == 24)
 		reg |= SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS;
 	else
@@ -1219,6 +1222,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 		} else {
 			can_lvds = true;
 		}
+
+		tcon->lvds_dual_link = of_property_read_bool(dev->of_node,
+							     "allwinner,lvds-dual-link");
 	} else {
 		can_lvds = false;
 	}
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index d36c304b1607..2a57d24e2772 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -98,6 +98,7 @@
 
 #define SUN4I_TCON0_LVDS_IF_REG			0x84
 #define SUN4I_TCON0_LVDS_IF_EN				BIT(31)
+#define SUN4I_TCON0_LVDS_IF_DUAL_LINK			BIT(30)
 #define SUN4I_TCON0_LVDS_IF_BITWIDTH_MASK		BIT(26)
 #define SUN4I_TCON0_LVDS_IF_BITWIDTH_18BITS		(1 << 26)
 #define SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS		(0 << 26)
@@ -263,6 +264,9 @@ struct sun4i_tcon {
 	/* Associated crtc */
 	struct sun4i_crtc		*crtc;
 
+	/* Is the LVDS link a dual-channel link? */
+	bool				lvds_dual_link;
+
 	int				id;
 
 	/* TCON list management */
-- 
2.24.1