drm/bridge: lt9611: fix polarity programming

Fix programming of hsync and vsync polarities

Fixes: 23278bf5 ("drm/bridge: Introduce LT9611 DSI to HDMI bridge")
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/20230118081658.2198520-4-dmitry.baryshkov@linaro.org

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

@@ -207,7 +207,6 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod
 
 		/* stage 2 */
 		{ 0x834a, 0x40 },
-		{ 0x831d, 0x10 },
 
 		/* MK limit */
 		{ 0x832d, 0x38 },
@@ -222,11 +221,19 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod
 		{ 0x8325, 0x00 },
 		{ 0x832a, 0x01 },
 		{ 0x834a, 0x10 },
-		{ 0x831d, 0x10 },
-		{ 0x8326, 0x37 },
 	};
+	u8 pol = 0x10;
 
-	regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+		pol |= 0x2;
+	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+		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));
 
 	switch (mode->hdisplay) {
 	case 640:
@@ -236,7 +243,7 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod
 		regmap_write(lt9611->regmap, 0x8326, 0x37);
 		break;
 	case 3840:
-		regmap_multi_reg_write(lt9611->regmap, reg_cfg2, ARRAY_SIZE(reg_cfg2));
+		regmap_write(lt9611->regmap, 0x8326, 0x37);
 		break;
 	}