drm/meson: add YUV422 output support

Support YUV422 output from the Amlogic Meson SoC VPU to the HDMI
controller. Without this YUV422 format out of the HDMI encoder
leads to using the dw-hdmi YUV444 to YUV422 color conversion which
gives wrong colors and a green line on the left edge of the screen.
Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Tested-by: Furkan Kardame <f.kardame@manjaro.org>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Dan Johansen <strit@manjaro.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220516072245.10745-1-christianshewitt@gmail.com

drivers/gpu/drm/meson/meson_encoder_hdmi.c

@@ -218,7 +218,8 @@ static void meson_encoder_hdmi_atomic_enable(struct drm_bridge *bridge,
 	if (encoder_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24) {
 		ycrcb_map = VPU_HDMI_OUTPUT_CRYCB;
 		yuv420_mode = true;
-	}
+	} else if (encoder_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYVY8_1X16)
+		ycrcb_map = VPU_HDMI_OUTPUT_CRYCB;
 
 	/* VENC + VENC-DVI Mode setup */
 	meson_venc_hdmi_mode_set(priv, vic, ycrcb_map, yuv420_mode, mode);
@@ -230,6 +231,10 @@ static void meson_encoder_hdmi_atomic_enable(struct drm_bridge *bridge,
 		/* Setup YUV420 to HDMI-TX, no 10bit diphering */
 		writel_relaxed(2 | (2 << 2),
 			       priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
+	else if (encoder_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYVY8_1X16)
+		/* Setup YUV422 to HDMI-TX, no 10bit diphering */
+		writel_relaxed(1 | (2 << 2),
+				priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
 	else
 		/* Setup YUV444 to HDMI-TX, no 10bit diphering */
 		writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
@@ -257,6 +262,7 @@ static void meson_encoder_hdmi_atomic_disable(struct drm_bridge *bridge,
 
 static const u32 meson_encoder_hdmi_out_bus_fmts[] = {
 	MEDIA_BUS_FMT_YUV8_1X24,
+	MEDIA_BUS_FMT_UYVY8_1X16,
 	MEDIA_BUS_FMT_UYYVYY8_0_5X24,
 };