drm/bridge: lt9611: properly program the dual host mode

If the bridge is connected using both DSI ports, the driver should use
both of them all the time. Correct programming sequence to always use
dual-port mode if both dsi0 and dsi1 are connected.
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230118081658.2198520-14-dmitry.baryshkov@linaro.org

drivers/gpu/drm/bridge/lontium-lt9611.c

@@ -118,7 +118,7 @@ static int lt9611_mipi_input_digital(struct lt9611 *lt9611,
 		{ 0x8306, 0x0a },
 	};
 
-	if (mode->hdisplay == 3840)
+	if (lt9611->dsi1_node)
 		reg_cfg[1].def = 0x03;
 
 	return regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));
@@ -191,16 +191,6 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod
 		{ 0x832d, 0x38 },
 		{ 0x8331, 0x08 },
 	};
-	const struct reg_sequence reg_cfg2[] = {
-		{ 0x830b, 0x03 },
-		{ 0x830c, 0xd0 },
-		{ 0x8348, 0x03 },
-		{ 0x8349, 0xe0 },
-		{ 0x8324, 0x72 },
-		{ 0x8325, 0x00 },
-		{ 0x832a, 0x01 },
-		{ 0x834a, 0x10 },
-	};
 	u8 pol = 0x10;
 
 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
@@ -209,10 +199,18 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod
 		pol |= 0x1;
 	regmap_write(lt9611->regmap, 0x831d, pol);
 
-	if (mode->hdisplay == 3840)
-		regmap_multi_reg_write(lt9611->regmap, reg_cfg2, ARRAY_SIZE(reg_cfg2));
-	else
 	regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));
+	if (lt9611->dsi1_node) {
+		unsigned int hact = mode->hdisplay;
+
+		hact >>= 2;
+		hact += 0x50;
+		hact = min(hact, 0x3e0U);
+		regmap_write(lt9611->regmap, 0x830b, hact / 256);
+		regmap_write(lt9611->regmap, 0x830c, hact % 256);
+		regmap_write(lt9611->regmap, 0x8348, hact / 256);
+		regmap_write(lt9611->regmap, 0x8349, hact % 256);
+	}
 
 	regmap_write(lt9611->regmap, 0x8326, pcr_m);