[PATCH RFC v2 0/8] drm/bridge: dw-hdmi: implement bus-format negotiation and YUV420 support

[PATCH RFC v2 0/8] drm/bridge: dw-hdmi: implement bus-format negotiation and YUV420 support

[Neil Armstrong]

This patchset is based on Boris's v2 "drm: Add support for bus-format negotiation" at [1]
patchset to implement full bus-format negotiation for DW-HDMI, including YUV420 support and
10/12/16bit YUV444, YUV422 and RGB. The Color Space Converter support is already implemented.

And the counterpart implementation in the Amlogic Meson VPU dw-hdmi glue :
- basic bus-format negotiation to select YUV444 bus-format as DW-HDMI input
- YUV420 support when HDMI2.0 YUV420 modeset

This is a follow-up from the previous attempts :
- "drm/meson: Add support for HDMI2.0 YUV420 4k60" at [2]
- "drm/meson: Add support for HDMI2.0 4k60" at [3]

Changes since RFC v1 at [4]:
- Rewrote negociation using the v2 patchset, including full DW-HDMI fmt negociation

[1] https://patchwork.freedesktop.org/patch/msgid/20190826152649.13820-1-boris.brezillon@collabora.com
[2] https://patchwork.freedesktop.org/patch/msgid/20190520133753.23871-1-narmstrong@baylibre.com
[3] https://patchwork.freedesktop.org/patch/msgid/1549022873-40549-1-git-send-email-narmstrong@baylibre.com
[4] https://patchwork.freedesktop.org/patch/msgid/20190820084109.24616-1-narmstrong@baylibre.com

Neil Armstrong (8):
  drm/meson: venc: make drm_display_mode const
  drm/meson: meson_dw_hdmi: switch to drm_bridge_funcs
  drm/bridge: synopsys: dw-hdmi: add bus format negociation
  drm/meson: dw-hdmi: stop enforcing input_bus_format
  drm/bridge: dw-hdmi: allow ycbcr420 modes for >= 0x200a
  drm/meson: venc: add support for YUV420 setup
  drm/meson: vclk: add support for YUV420 setup
  drm/meson: Add YUV420 output support

 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 251 +++++++++++++++++++++-
 drivers/gpu/drm/meson/meson_dw_hdmi.c     | 164 +++++++++++---
 drivers/gpu/drm/meson/meson_vclk.c        |  93 ++++++--
 drivers/gpu/drm/meson/meson_vclk.h        |   7 +-
 drivers/gpu/drm/meson/meson_venc.c        |  10 +-
 drivers/gpu/drm/meson/meson_venc.h        |   4 +-
 drivers/gpu/drm/meson/meson_venc_cvbs.c   |   3 +-
 include/drm/bridge/dw_hdmi.h              |   1 +
 8 files changed, 466 insertions(+), 67 deletions(-)

-- 
2.22.0

[PATCH RFC v2 1/8] drm/meson: venc: make drm_display_mode const

[Neil Armstrong]

Before switching to bridge funcs, make sure drm_display_mode is passed
as const to the venc functions.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/meson/meson_venc.c | 2 +-
 drivers/gpu/drm/meson/meson_venc.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_venc.c b/drivers/gpu/drm/meson/meson_venc.c
index 679d2274531c..d2d4c3ebf46b 100644
--- a/drivers/gpu/drm/meson/meson_venc.c
+++ b/drivers/gpu/drm/meson/meson_venc.c
@@ -946,7 +946,7 @@ bool meson_venc_hdmi_venc_repeat(int vic)
 EXPORT_SYMBOL_GPL(meson_venc_hdmi_venc_repeat);
 
 void meson_venc_hdmi_mode_set(struct meson_drm *priv, int vic,
-			      struct drm_display_mode *mode)
+			      const struct drm_display_mode *mode)
 {
 	union meson_hdmi_venc_mode *vmode = NULL;
 	union meson_hdmi_venc_mode vmode_dmt;
diff --git a/drivers/gpu/drm/meson/meson_venc.h b/drivers/gpu/drm/meson/meson_venc.h
index 576768bdd08d..1abdcbdf51c0 100644
--- a/drivers/gpu/drm/meson/meson_venc.h
+++ b/drivers/gpu/drm/meson/meson_venc.h
@@ -60,7 +60,7 @@ extern struct meson_cvbs_enci_mode meson_cvbs_enci_ntsc;
 void meson_venci_cvbs_mode_set(struct meson_drm *priv,
 			       struct meson_cvbs_enci_mode *mode);
 void meson_venc_hdmi_mode_set(struct meson_drm *priv, int vic,
-			      struct drm_display_mode *mode);
+			      const struct drm_display_mode *mode);
 unsigned int meson_venci_get_field(struct meson_drm *priv);
 
 void meson_venc_enable_vsync(struct meson_drm *priv);
-- 
2.22.0

[PATCH RFC v2 2/8] drm/meson: meson_dw_hdmi: switch to drm_bridge_funcs

[Neil Armstrong]

Switch the dw-hdmi driver to drm_bridge_funcs, and implement the
atomic_get_input_bus_fmts/atomic_get_output_bus_fmts.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 67 +++++++++++++++++++++------
 1 file changed, 54 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index f893ebd0b799..333583ef3ab9 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -368,7 +368,7 @@ static inline void meson_dw_hdmi_phy_reset(struct meson_dw_hdmi *dw_hdmi)
 }
 
 static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
-			     struct drm_display_mode *mode)
+			     const struct drm_display_mode *mode)
 {
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
@@ -663,6 +663,10 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 /* Encoder */
 
+static const u32 meson_dw_hdmi_out_bus_fmts[] = {
+	MEDIA_BUS_FMT_YUV8_1X24,
+};
+
 static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
 {
 	drm_encoder_cleanup(encoder);
@@ -672,15 +676,50 @@ static const struct drm_encoder_funcs meson_venc_hdmi_encoder_funcs = {
 	.destroy        = meson_venc_hdmi_encoder_destroy,
 };
 
-static int meson_venc_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
+static void
+meson_venc_hdmi_encoder_get_out_bus_fmts(struct drm_bridge *bridge,
+					 struct drm_bridge_state *bridge_state,
+					 struct drm_crtc_state *crtc_state,
+					 struct drm_connector_state *conn_state,
+					 unsigned int *num_output_fmts,
+					 u32 *output_fmts)
+{
+	*num_output_fmts = ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts);
+
+	if (output_fmts)
+		memcpy(output_fmts, meson_dw_hdmi_out_bus_fmts,
+		       ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts));
+}
+
+static void
+meson_venc_hdmi_encoder_get_inp_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					u32 output_fmt,
+					unsigned int *num_input_fmts,
+					u32 *input_fmts)
+{
+	if (output_fmt == meson_dw_hdmi_out_bus_fmts[0]) {
+		*num_input_fmts = 1;
+		if (input_fmts)
+			input_fmts[0] = output_fmt;
+	}
+	else
+		*num_input_fmts = 0;
+}
+
+static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
 					struct drm_crtc_state *crtc_state,
 					struct drm_connector_state *conn_state)
 {
 	return 0;
 }
 
-static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
+static void meson_venc_hdmi_encoder_disable(struct drm_bridge *bridge)
 {
+	struct drm_encoder *encoder = bridge_to_encoder(bridge);
 	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
 	struct meson_drm *priv = dw_hdmi->priv;
 
@@ -693,8 +732,9 @@ static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
 	writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
 }
 
-static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
+static void meson_venc_hdmi_encoder_enable(struct drm_bridge *bridge)
 {
+	struct drm_encoder *encoder = bridge_to_encoder(bridge);
 	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
 	struct meson_drm *priv = dw_hdmi->priv;
 
@@ -706,10 +746,11 @@ static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
 		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
 }
 
-static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
-				   struct drm_display_mode *mode,
-				   struct drm_display_mode *adjusted_mode)
+static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
+				   const struct drm_display_mode *mode,
+				   const struct drm_display_mode *adjusted_mode)
 {
+	struct drm_encoder *encoder = bridge_to_encoder(bridge);
 	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
@@ -726,11 +767,12 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
 	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
 }
 
-static const struct drm_encoder_helper_funcs
-				meson_venc_hdmi_encoder_helper_funcs = {
-	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
-	.disable	= meson_venc_hdmi_encoder_disable,
+static const struct drm_bridge_funcs meson_venc_hdmi_encoder_bridge_funcs = {
 	.enable		= meson_venc_hdmi_encoder_enable,
+	.disable	= meson_venc_hdmi_encoder_disable,
+	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
+	.atomic_get_output_bus_fmts = meson_venc_hdmi_encoder_get_out_bus_fmts,
+	.atomic_get_input_bus_fmts = meson_venc_hdmi_encoder_get_inp_bus_fmts,
 	.mode_set	= meson_venc_hdmi_encoder_mode_set,
 };
 
@@ -912,8 +954,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 
 	/* Encoder */
 
-	drm_encoder_helper_add(encoder, &meson_venc_hdmi_encoder_helper_funcs);
-
+	encoder->bridge.funcs = &meson_venc_hdmi_encoder_bridge_funcs;
 	ret = drm_encoder_init(drm, encoder, &meson_venc_hdmi_encoder_funcs,
 			       DRM_MODE_ENCODER_TMDS, "meson_hdmi");
 	if (ret) {
-- 
2.22.0

[PATCH RFC v2 3/8] drm/bridge: synopsys: dw-hdmi: add bus format negociation

[Neil Armstrong]

Add the atomic_get_output_bus_fmts, atomic_get_input_bus_fmts to negociate
the possible output and input formats for the current mode and monitor,
and use the negociated formats in a basic atomic_check callback.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 245 +++++++++++++++++++++-
 1 file changed, 241 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index bd65d0479683..00aacad51e29 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -1987,11 +1987,10 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
 	hdmi->hdmi_data.video_mode.mpixelrepetitionoutput = 0;
 	hdmi->hdmi_data.video_mode.mpixelrepetitioninput = 0;
 
-	/* TOFIX: Get input format from plat data or fallback to RGB888 */
 	if (hdmi->plat_data->input_bus_format)
 		hdmi->hdmi_data.enc_in_bus_format =
 			hdmi->plat_data->input_bus_format;
-	else
+	else if (hdmi->hdmi_data.enc_in_bus_format == MEDIA_BUS_FMT_FIXED)
 		hdmi->hdmi_data.enc_in_bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 
 	/* TOFIX: Get input encoding from plat data or fallback to none */
@@ -2001,8 +2000,8 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
 	else
 		hdmi->hdmi_data.enc_in_encoding = V4L2_YCBCR_ENC_DEFAULT;
 
-	/* TOFIX: Default to RGB888 output format */
-	hdmi->hdmi_data.enc_out_bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	if (hdmi->hdmi_data.enc_out_bus_format == MEDIA_BUS_FMT_FIXED)
+		hdmi->hdmi_data.enc_out_bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 
 	hdmi->hdmi_data.pix_repet_factor = 0;
 	hdmi->hdmi_data.hdcp_enable = 0;
@@ -2227,6 +2226,240 @@ static const struct drm_connector_helper_funcs dw_hdmi_connector_helper_funcs =
 	.get_modes = dw_hdmi_connector_get_modes,
 };
 
+static void dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					unsigned int *num_output_fmts,
+					u32 *output_fmts)
+{
+	struct drm_connector *conn = conn_state->connector;
+	struct drm_display_info *info = &conn->display_info;
+	struct drm_display_mode *mode = &crtc_state->mode;
+	bool is_hdmi2_sink = info->hdmi.scdc.supported;	
+	int i = 0;
+
+	/*
+	 * If the current mode enforces 4:2:0, force the output but format
+	 * to 4:2:0 and do not add the YUV422/444/RGB formats
+	 */
+	if (drm_mode_is_420_only(info, mode) ||
+	    (!is_hdmi2_sink && drm_mode_is_420_also(info, mode))) {
+
+		/* Order bus formats from 16bit to 8bit if supported */
+		if (info->bpc == 16 &&
+		    (info->hdmi.y420_dc_modes & DRM_EDID_YCBCR420_DC_48)) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_UYYVYY16_0_5X48;
+			++i;
+		}
+
+		if (info->bpc >= 12 &&
+		    (info->hdmi.y420_dc_modes & DRM_EDID_YCBCR420_DC_36)) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_UYYVYY12_0_5X36;
+			++i;
+		}
+
+		if (info->bpc >= 10 &&
+		    (info->hdmi.y420_dc_modes & DRM_EDID_YCBCR420_DC_30)) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_UYYVYY10_0_5X30;
+			++i;
+		}
+
+		/* Default 8bit fallback */
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_UYYVYY8_0_5X24;
+		++i;
+
+		*num_output_fmts = i;
+
+		return;
+	}
+
+	/*
+	 * Order bus formats from 16bit to 8bit and from YUV422 to RGB
+	 * if supported. In any case the default RGB888 format is added
+	 */
+
+	if (info->bpc == 16) {
+		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_YUV16_1X48;
+			++i;
+		}
+
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_RGB161616_1X48;
+		++i;
+	}
+
+	if (info->bpc >= 12) {
+		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_UYVY12_1X24;
+			++i;
+		}
+
+		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_YUV12_1X36;
+			++i;
+		}
+
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_RGB121212_1X36;
+		++i;
+	}
+
+	if (info->bpc >= 10) {
+		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_UYVY10_1X20;
+			++i;
+		}
+
+		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444) {
+			if (output_fmts)
+				output_fmts[i] = MEDIA_BUS_FMT_YUV10_1X30;
+			++i;
+		}
+
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_RGB101010_1X30;
+		++i;
+	}
+
+	if (info->color_formats & DRM_COLOR_FORMAT_YCRCB422) {
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_UYVY8_1X16;
+		++i;
+	}
+
+	if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444) {
+		if (output_fmts)
+			output_fmts[i] = MEDIA_BUS_FMT_YUV8_1X24;
+		++i;
+	}
+
+	/* Default 8bit RGB fallback */
+	if (output_fmts)
+		output_fmts[i] = MEDIA_BUS_FMT_RGB888_1X24;
+	++i;
+
+	*num_output_fmts = i;
+}
+
+static void dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					u32 output_fmt,
+					unsigned int *num_input_fmts,
+					u32 *input_fmts)
+{
+	int i = 0;
+
+	switch (output_fmt) {
+		/* 8bit */
+		case MEDIA_BUS_FMT_RGB888_1X24:
+			if (input_fmts)
+				input_fmts[i] = MEDIA_BUS_FMT_RGB888_1X24;
+			++i;
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_YUV8_1X24:
+			if (input_fmts)
+				input_fmts[i] = MEDIA_BUS_FMT_YUV8_1X24;
+			++i;
+			break;
+		case MEDIA_BUS_FMT_UYVY8_1X16:
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_UYYVYY8_0_5X24:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+			break;
+
+		/* 10bit */
+		case MEDIA_BUS_FMT_RGB101010_1X30:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_YUV10_1X30:
+			if (input_fmts)
+				input_fmts[i] = MEDIA_BUS_FMT_YUV10_1X30;
+			++i;
+			break;
+		case MEDIA_BUS_FMT_UYVY10_1X20:
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_UYYVYY10_0_5X30:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+			break;
+
+		/* 12bit */
+		case MEDIA_BUS_FMT_RGB121212_1X36:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_YUV12_1X36:
+			if (input_fmts)
+				input_fmts[i] = MEDIA_BUS_FMT_YUV12_1X36;
+			++i;
+			break;
+		case MEDIA_BUS_FMT_UYVY12_1X24:
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_UYYVYY12_0_5X36:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+			break;
+
+		/* 16bit */
+		case MEDIA_BUS_FMT_RGB161616_1X48:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+		/* Fallthrought */
+		case MEDIA_BUS_FMT_YUV16_1X48:
+			if (input_fmts)
+				input_fmts[i] = MEDIA_BUS_FMT_YUV16_1X48;
+			++i;
+			break;
+		case MEDIA_BUS_FMT_UYYVYY16_0_5X48:
+			if (input_fmts)
+				input_fmts[i] = output_fmt;
+			++i;
+			break;
+	}
+
+	*num_input_fmts = i;
+}
+
+static int dw_hdmi_bridge_atomic_check(struct drm_bridge *bridge,
+				       struct drm_bridge_state *bridge_state,
+				       struct drm_crtc_state *crtc_state,
+				       struct drm_connector_state *conn_state)
+{
+	struct dw_hdmi *hdmi = bridge->driver_private;
+
+	dev_dbg(hdmi->dev, "selected output format %x\n",
+			bridge_state->output_bus_cfg.fmt);
+
+	hdmi->hdmi_data.enc_out_bus_format = bridge_state->output_bus_cfg.fmt;
+
+	dev_dbg(hdmi->dev, "selected input format %x\n",
+			bridge_state->input_bus_cfg.fmt);
+
+	hdmi->hdmi_data.enc_in_bus_format = bridge_state->input_bus_cfg.fmt;
+
+	return 0;
+}
+
 static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
 {
 	struct dw_hdmi *hdmi = bridge->driver_private;
@@ -2327,6 +2560,9 @@ static void dw_hdmi_bridge_enable(struct drm_bridge *bridge)
 static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
 	.attach = dw_hdmi_bridge_attach,
 	.detach = dw_hdmi_bridge_detach,
+	.atomic_check = dw_hdmi_bridge_atomic_check,
+	.atomic_get_output_bus_fmts = dw_hdmi_bridge_atomic_get_output_bus_fmts,
+	.atomic_get_input_bus_fmts = dw_hdmi_bridge_atomic_get_input_bus_fmts,
 	.enable = dw_hdmi_bridge_enable,
 	.disable = dw_hdmi_bridge_disable,
 	.mode_set = dw_hdmi_bridge_mode_set,
@@ -2790,6 +3026,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
 
 	hdmi->bridge.driver_private = hdmi;
 	hdmi->bridge.funcs = &dw_hdmi_bridge_funcs;
+
 #ifdef CONFIG_OF
 	hdmi->bridge.of_node = pdev->dev.of_node;
 #endif
-- 
2.22.0

[PATCH RFC v2 4/8] drm/meson: dw-hdmi: stop enforcing input_bus_format

[Neil Armstrong]

To allow using formats from negociation, stop enforcing input_bus_format
in the private dw-plat-data struct.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 333583ef3ab9..9ae24cc5faa2 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -1007,7 +1007,6 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 	dw_plat_data->phy_ops = &meson_dw_hdmi_phy_ops;
 	dw_plat_data->phy_name = "meson_dw_hdmi_phy";
 	dw_plat_data->phy_data = meson_dw_hdmi;
-	dw_plat_data->input_bus_format = MEDIA_BUS_FMT_YUV8_1X24;
 	dw_plat_data->input_bus_encoding = V4L2_YCBCR_ENC_709;
 
 	platform_set_drvdata(pdev, meson_dw_hdmi);
-- 
2.22.0

[PATCH RFC v2 5/8] drm/bridge: dw-hdmi: allow ycbcr420 modes for >= 0x200a

[Neil Armstrong]

Now the DW-HDMI Controller supports the HDMI2.0 modes, enable support
for these modes in the connector if the platform supports them.
We limit these modes to DW-HDMI IP version >= 0x200a which
are designed to support HDMI2.0 display modes.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 6 ++++++
 include/drm/bridge/dw_hdmi.h              | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 00aacad51e29..048409af13d2 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -3031,6 +3031,12 @@ __dw_hdmi_probe(struct platform_device *pdev,
 	hdmi->bridge.of_node = pdev->dev.of_node;
 #endif
 
+	if (hdmi->version >= 0x200a)
+		hdmi->connector.ycbcr_420_allowed =
+			hdmi->plat_data->ycbcr_420_allowed;
+	else
+		hdmi->connector.ycbcr_420_allowed = false;
+
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.parent = dev;
 	pdevinfo.id = PLATFORM_DEVID_AUTO;
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index cf528c289857..25a884523b45 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -126,6 +126,7 @@ struct dw_hdmi_plat_data {
 					   const struct drm_display_mode *mode);
 	unsigned long input_bus_format;
 	unsigned long input_bus_encoding;
+	bool ycbcr_420_allowed;
 
 	/* Vendor PHY support */
 	const struct dw_hdmi_phy_ops *phy_ops;
-- 
2.22.0

[PATCH RFC v2 6/8] drm/meson: venc: add support for YUV420 setup

[Neil Armstrong]

This patch adds encoding support for the YUV420 output from the
Amlogic Meson SoCs Video Processing Unit to the HDMI Controller.

The YUV420 is obtained by generating a YUV444 pixel stream like
the classic HDMI display modes, but then the Video Encoder output
can be configured to down-sample the YUV444 pixel stream to a YUV420
stream.

In addition if pixel stream down-sampling, the Y Cb Cr components must
also be mapped differently to align with the HDMI2.0 specifications.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 3 ++-
 drivers/gpu/drm/meson/meson_venc.c    | 8 +++++---
 drivers/gpu/drm/meson/meson_venc.h    | 2 ++
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 9ae24cc5faa2..2c69024e5bcf 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -758,7 +758,8 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
 	DRM_DEBUG_DRIVER("\"%s\" vic %d\n", mode->name, vic);
 
 	/* VENC + VENC-DVI Mode setup */
-	meson_venc_hdmi_mode_set(priv, vic, mode);
+	meson_venc_hdmi_mode_set(priv, vic, ycrcb_map, false,
+				 VPU_HDMI_OUTPUT_CBYCR);
 
 	/* VCLK Set clock */
 	dw_hdmi_set_vclk(dw_hdmi, mode);
diff --git a/drivers/gpu/drm/meson/meson_venc.c b/drivers/gpu/drm/meson/meson_venc.c
index d2d4c3ebf46b..be1fb08a80f5 100644
--- a/drivers/gpu/drm/meson/meson_venc.c
+++ b/drivers/gpu/drm/meson/meson_venc.c
@@ -946,6 +946,8 @@ bool meson_venc_hdmi_venc_repeat(int vic)
 EXPORT_SYMBOL_GPL(meson_venc_hdmi_venc_repeat);
 
 void meson_venc_hdmi_mode_set(struct meson_drm *priv, int vic,
+			      unsigned int ycrcb_map,
+			      bool yuv420_mode,
 			      const struct drm_display_mode *mode)
 {
 	union meson_hdmi_venc_mode *vmode = NULL;
@@ -1528,14 +1530,14 @@ void meson_venc_hdmi_mode_set(struct meson_drm *priv, int vic,
 	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
 		reg |= VPU_HDMI_INV_VSYNC;
 
-	/* Output data format: CbYCr */
-	reg |= VPU_HDMI_OUTPUT_CBYCR;
+	/* Output data format */
+	reg |= ycrcb_map;
 
 	/*
 	 * Write rate to the async FIFO between VENC and HDMI.
 	 * One write every 2 wr_clk.
 	 */
-	if (venc_repeat)
+	if (venc_repeat || yuv420_mode)
 		reg |= VPU_HDMI_WR_RATE(2);
 
 	/*
diff --git a/drivers/gpu/drm/meson/meson_venc.h b/drivers/gpu/drm/meson/meson_venc.h
index 1abdcbdf51c0..9138255ffc9e 100644
--- a/drivers/gpu/drm/meson/meson_venc.h
+++ b/drivers/gpu/drm/meson/meson_venc.h
@@ -60,6 +60,8 @@ extern struct meson_cvbs_enci_mode meson_cvbs_enci_ntsc;
 void meson_venci_cvbs_mode_set(struct meson_drm *priv,
 			       struct meson_cvbs_enci_mode *mode);
 void meson_venc_hdmi_mode_set(struct meson_drm *priv, int vic,
+			      unsigned int ycrcb_map,
+			      bool yuv420_mode,
 			      const struct drm_display_mode *mode);
 unsigned int meson_venci_get_field(struct meson_drm *priv);
 
-- 
2.22.0

[PATCH RFC v2 7/8] drm/meson: vclk: add support for YUV420 setup

[Neil Armstrong]

This patch adds clocking support for the YUV420 output from the
Amlogic Meson SoCs Video Processing Unit to the HDMI Controller.

The YUV420 is obtained by generating a YUV444 pixel stream like
the classic HDMI display modes, but then the Video Encoder output
can be configured to down-sample the YUV444 pixel stream to a YUV420
stream.

This mode needs a different clock generation scheme since the TMDS PHY
clock must match the 10x ratio with the YUV420 pixel clock, but
the video encoder must run at 2x the pixel clock.

This patch adds the TMDS PHY clock value in all the video clock setup
in order to better support these specific uses cases and switch
to the Common Clock framework for clocks handling in the future.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c   | 24 ++++---
 drivers/gpu/drm/meson/meson_vclk.c      | 93 +++++++++++++++++++------
 drivers/gpu/drm/meson/meson_vclk.h      |  7 +-
 drivers/gpu/drm/meson/meson_venc_cvbs.c |  3 +-
 4 files changed, 93 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 2c69024e5bcf..38316c6cac26 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -372,15 +372,19 @@ static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
 {
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
+	unsigned int phy_freq;
 	unsigned int vclk_freq;
 	unsigned int venc_freq;
 	unsigned int hdmi_freq;
 
 	vclk_freq = mode->clock;
 
+	/* TMDS clock is pixel_clock * 10 */
+	phy_freq = vclk_freq * 10;
+
 	if (!vic) {
-		meson_vclk_setup(priv, MESON_VCLK_TARGET_DMT, vclk_freq,
-				 vclk_freq, vclk_freq, false);
+		meson_vclk_setup(priv, MESON_VCLK_TARGET_DMT, phy_freq,
+				 vclk_freq, vclk_freq, vclk_freq, false);
 		return;
 	}
 
@@ -398,11 +402,11 @@ static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		venc_freq /= 2;
 
-	DRM_DEBUG_DRIVER("vclk:%d venc=%d hdmi=%d enci=%d\n",
-		vclk_freq, venc_freq, hdmi_freq,
+	DRM_DEBUG_DRIVER("vclk:%d phy=%d venc=%d hdmi=%d enci=%d\n",
+		phy_freq, vclk_freq, venc_freq, hdmi_freq,
 		priv->venc.hdmi_use_enci);
 
-	meson_vclk_setup(priv, MESON_VCLK_TARGET_HDMI, vclk_freq,
+	meson_vclk_setup(priv, MESON_VCLK_TARGET_HDMI, phy_freq, vclk_freq,
 			 venc_freq, hdmi_freq, priv->venc.hdmi_use_enci);
 }
 
@@ -613,6 +617,7 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 		   const struct drm_display_mode *mode)
 {
 	struct meson_drm *priv = connector->dev->dev_private;
+	unsigned int phy_freq;
 	unsigned int vclk_freq;
 	unsigned int venc_freq;
 	unsigned int hdmi_freq;
@@ -639,6 +644,9 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 	vclk_freq = mode->clock;
 
+	/* TMDS clock is pixel_clock * 10 */
+	phy_freq = vclk_freq * 10;
+
 	/* 480i/576i needs global pixel doubling */
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		vclk_freq *= 2;
@@ -655,10 +663,10 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		venc_freq /= 2;
 
-	dev_dbg(connector->dev->dev, "%s: vclk:%d venc=%d hdmi=%d\n", __func__,
-		vclk_freq, venc_freq, hdmi_freq);
+	dev_dbg(connector->dev->dev, "%s: vclk:%d phy=%d venc=%d hdmi=%d\n",
+		__func__, phy_freq, vclk_freq, venc_freq, hdmi_freq);
 
-	return meson_vclk_vic_supported_freq(vclk_freq);
+	return meson_vclk_vic_supported_freq(phy_freq, vclk_freq);
 }
 
 /* Encoder */
diff --git a/drivers/gpu/drm/meson/meson_vclk.c b/drivers/gpu/drm/meson/meson_vclk.c
index 869231c93617..a7cbbc75ef1b 100644
--- a/drivers/gpu/drm/meson/meson_vclk.c
+++ b/drivers/gpu/drm/meson/meson_vclk.c
@@ -354,12 +354,17 @@ enum {
 /* 2970 /1 /1 /1 /5 /2  => /1 /1 */
 	MESON_VCLK_HDMI_297000,
 /* 5940 /1 /1 /2 /5 /1  => /1 /1 */
-	MESON_VCLK_HDMI_594000
+	MESON_VCLK_HDMI_594000,
+/* 2970 /1 /1 /1 /5 /1  => /1 /2 */
+	MESON_VCLK_HDMI_594000_YUV420,
 };
 
 struct meson_vclk_params {
+	unsigned int pll_freq;
+	unsigned int phy_freq;
+	unsigned int vclk_freq;
+	unsigned int venc_freq;
 	unsigned int pixel_freq;
-	unsigned int pll_base_freq;
 	unsigned int pll_od1;
 	unsigned int pll_od2;
 	unsigned int pll_od3;
@@ -367,8 +372,11 @@ struct meson_vclk_params {
 	unsigned int vclk_div;
 } params[] = {
 	[MESON_VCLK_HDMI_ENCI_54000] = {
+		.pll_freq = 4320000,
+		.phy_freq = 270000,
+		.vclk_freq = 54000,
+		.venc_freq = 54000,
 		.pixel_freq = 54000,
-		.pll_base_freq = 4320000,
 		.pll_od1 = 4,
 		.pll_od2 = 4,
 		.pll_od3 = 1,
@@ -376,8 +384,11 @@ struct meson_vclk_params {
 		.vclk_div = 1,
 	},
 	[MESON_VCLK_HDMI_DDR_54000] = {
-		.pixel_freq = 54000,
-		.pll_base_freq = 4320000,
+		.pll_freq = 4320000,
+		.phy_freq = 270000,
+		.vclk_freq = 54000,
+		.venc_freq = 54000,
+		.pixel_freq = 27000,
 		.pll_od1 = 4,
 		.pll_od2 = 4,
 		.pll_od3 = 1,
@@ -385,8 +396,11 @@ struct meson_vclk_params {
 		.vclk_div = 1,
 	},
 	[MESON_VCLK_HDMI_DDR_148500] = {
-		.pixel_freq = 148500,
-		.pll_base_freq = 2970000,
+		.pll_freq = 2970000,
+		.phy_freq = 742500,
+		.vclk_freq = 148500,
+		.venc_freq = 148500,
+		.pixel_freq = 74250,
 		.pll_od1 = 4,
 		.pll_od2 = 1,
 		.pll_od3 = 1,
@@ -394,8 +408,11 @@ struct meson_vclk_params {
 		.vclk_div = 1,
 	},
 	[MESON_VCLK_HDMI_74250] = {
+		.pll_freq = 2970000,
+		.phy_freq = 742500,
+		.vclk_freq = 74250,
+		.venc_freq = 74250,
 		.pixel_freq = 74250,
-		.pll_base_freq = 2970000,
 		.pll_od1 = 2,
 		.pll_od2 = 2,
 		.pll_od3 = 2,
@@ -403,8 +420,11 @@ struct meson_vclk_params {
 		.vclk_div = 1,
 	},
 	[MESON_VCLK_HDMI_148500] = {
+		.pll_freq = 2970000,
+		.phy_freq = 1485000,
+		.vclk_freq = 148500,
+		.venc_freq = 148500,
 		.pixel_freq = 148500,
-		.pll_base_freq = 2970000,
 		.pll_od1 = 1,
 		.pll_od2 = 2,
 		.pll_od3 = 2,
@@ -412,8 +432,11 @@ struct meson_vclk_params {
 		.vclk_div = 1,
 	},
 	[MESON_VCLK_HDMI_297000] = {
+		.pll_freq = 5940000,
+		.phy_freq = 2970000,
+		.venc_freq = 297000,
+		.vclk_freq = 297000,
 		.pixel_freq = 297000,
-		.pll_base_freq = 5940000,
 		.pll_od1 = 2,
 		.pll_od2 = 1,
 		.pll_od3 = 1,
@@ -421,14 +444,29 @@ struct meson_vclk_params {
 		.vclk_div = 2,
 	},
 	[MESON_VCLK_HDMI_594000] = {
+		.pll_freq = 5940000,
+		.phy_freq = 5940000,
+		.venc_freq = 594000,
+		.vclk_freq = 594000,
 		.pixel_freq = 594000,
-		.pll_base_freq = 5940000,
 		.pll_od1 = 1,
 		.pll_od2 = 1,
 		.pll_od3 = 2,
 		.vid_pll_div = VID_PLL_DIV_5,
 		.vclk_div = 1,
 	},
+	[MESON_VCLK_HDMI_594000_YUV420] = {
+		.pll_freq = 5940000,
+		.phy_freq = 2970000,
+		.venc_freq = 594000,
+		.vclk_freq = 594000,
+		.pixel_freq = 297000,
+		.pll_od1 = 2,
+		.pll_od2 = 1,
+		.pll_od3 = 1,
+		.vid_pll_div = VID_PLL_DIV_5,
+		.vclk_div = 1,
+	},
 	{ /* sentinel */ },
 };
 
@@ -696,6 +734,7 @@ static void meson_hdmi_pll_generic_set(struct meson_drm *priv,
 	unsigned int od, m, frac, od1, od2, od3;
 
 	if (meson_hdmi_pll_find_params(priv, pll_freq, &m, &frac, &od)) {
+		/* OD2 goes to the PHY, and needs to be *10, so keep OD3=1 */
 		od3 = 1;
 		if (od < 4) {
 			od1 = 2;
@@ -718,21 +757,28 @@ static void meson_hdmi_pll_generic_set(struct meson_drm *priv,
 }
 
 enum drm_mode_status
-meson_vclk_vic_supported_freq(unsigned int freq)
+meson_vclk_vic_supported_freq(unsigned int phy_freq,
+			      unsigned int vclk_freq)
 {
 	int i;
 
-	DRM_DEBUG_DRIVER("freq = %d\n", freq);
+	DRM_DEBUG_DRIVER("phy_freq = %d vclk_freq = %d\n",
+			 phy_freq, vclk_freq);
 
 	for (i = 0 ; params[i].pixel_freq ; ++i) {
 		DRM_DEBUG_DRIVER("i = %d pixel_freq = %d alt = %d\n",
 				 i, params[i].pixel_freq,
 				 FREQ_1000_1001(params[i].pixel_freq));
+		DRM_DEBUG_DRIVER("i = %d phy_freq = %d alt = %d\n",
+				 i, params[i].phy_freq,
+				 FREQ_1000_1001(params[i].phy_freq/10)*10);
 		/* Match strict frequency */
-		if (freq == params[i].pixel_freq)
+		if (phy_freq == params[i].phy_freq &&
+		    vclk_freq == params[i].vclk_freq)
 			return MODE_OK;
 		/* Match 1000/1001 variant */
-		if (freq == FREQ_1000_1001(params[i].pixel_freq))
+		if (phy_freq == (FREQ_1000_1001(params[i].phy_freq/10)*10) &&
+		    vclk_freq == FREQ_1000_1001(params[i].vclk_freq))
 			return MODE_OK;
 	}
 
@@ -960,8 +1006,9 @@ static void meson_vclk_set(struct meson_drm *priv, unsigned int pll_base_freq,
 }
 
 void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
-		      unsigned int vclk_freq, unsigned int venc_freq,
-		      unsigned int dac_freq, bool hdmi_use_enci)
+		      unsigned int phy_freq, unsigned int vclk_freq,
+		      unsigned int venc_freq, unsigned int dac_freq,
+		      bool hdmi_use_enci)
 {
 	bool vic_alternate_clock = false;
 	unsigned int freq;
@@ -981,7 +1028,7 @@ void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		 * - venc_div = 1
 		 * - encp encoder
 		 */
-		meson_vclk_set(priv, vclk_freq * 10, 0, 0, 0,
+		meson_vclk_set(priv, phy_freq, 0, 0, 0,
 			       VID_PLL_DIV_5, 2, 1, 1, false, false);
 		return;
 	}
@@ -1003,9 +1050,11 @@ void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 	}
 
 	for (freq = 0 ; params[freq].pixel_freq ; ++freq) {
-		if (vclk_freq == params[freq].pixel_freq ||
-		    vclk_freq == FREQ_1000_1001(params[freq].pixel_freq)) {
-			if (vclk_freq != params[freq].pixel_freq)
+		if ((phy_freq == params[freq].phy_freq ||
+		     phy_freq == FREQ_1000_1001(params[freq].phy_freq/10)*10) &&
+		    (vclk_freq == params[freq].vclk_freq ||
+		     vclk_freq == FREQ_1000_1001(params[freq].vclk_freq))) {
+			if (vclk_freq != params[freq].vclk_freq)
 				vic_alternate_clock = true;
 			else
 				vic_alternate_clock = false;
@@ -1034,7 +1083,7 @@ void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
 		return;
 	}
 
-	meson_vclk_set(priv, params[freq].pll_base_freq,
+	meson_vclk_set(priv, params[freq].pll_freq,
 		       params[freq].pll_od1, params[freq].pll_od2,
 		       params[freq].pll_od3, params[freq].vid_pll_div,
 		       params[freq].vclk_div, hdmi_tx_div, venc_div,
diff --git a/drivers/gpu/drm/meson/meson_vclk.h b/drivers/gpu/drm/meson/meson_vclk.h
index b62125540aef..aed0ab2efa71 100644
--- a/drivers/gpu/drm/meson/meson_vclk.h
+++ b/drivers/gpu/drm/meson/meson_vclk.h
@@ -25,10 +25,11 @@ enum {
 enum drm_mode_status
 meson_vclk_dmt_supported_freq(struct meson_drm *priv, unsigned int freq);
 enum drm_mode_status
-meson_vclk_vic_supported_freq(unsigned int freq);
+meson_vclk_vic_supported_freq(unsigned int phy_freq, unsigned int vclk_freq);
 
 void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
-		      unsigned int vclk_freq, unsigned int venc_freq,
-		      unsigned int dac_freq, bool hdmi_use_enci);
+		      unsigned int phy_freq, unsigned int vclk_freq,
+		      unsigned int venc_freq, unsigned int dac_freq,
+		      bool hdmi_use_enci);
 
 #endif /* __MESON_VCLK_H */
diff --git a/drivers/gpu/drm/meson/meson_venc_cvbs.c b/drivers/gpu/drm/meson/meson_venc_cvbs.c
index 6dc130a24070..564def4d0b04 100644
--- a/drivers/gpu/drm/meson/meson_venc_cvbs.c
+++ b/drivers/gpu/drm/meson/meson_venc_cvbs.c
@@ -206,7 +206,8 @@ static void meson_venc_cvbs_encoder_mode_set(struct drm_encoder *encoder,
 			/* Setup 27MHz vclk2 for ENCI and VDAC */
 			meson_vclk_setup(priv, MESON_VCLK_TARGET_CVBS,
 					 MESON_VCLK_CVBS, MESON_VCLK_CVBS,
-					 MESON_VCLK_CVBS, true);
+					 MESON_VCLK_CVBS, MESON_VCLK_CVBS,
+					 true);
 			break;
 		}
 	}
-- 
2.22.0

[PATCH RFC v2 8/8] drm/meson: Add YUV420 output support

[Neil Armstrong]

This patch adds support for the YUV420 output from the Amlogic Meson SoCs
Video Processing Unit to the HDMI Controller.

The YUV420 is obtained by generating a YUV444 pixel stream like
the classic HDMI display modes, but then the Video Encoder output
can be configured to down-sample the YUV444 pixel stream to a YUV420
stream.
In addition if pixel stream down-sampling, the Y Cb Cr components must
also be mapped differently to align with the HDMI2.0 specifications.

This mode needs a different clock generation scheme since the TMDS PHY
clock must match the 10x ration with the YUV420 pixel clock, but
the video encoder must run at 2x the pixel clock.

This patch enables the bridge bus format negociation, and handles
the YUV420 case if selected by the negociation.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/gpu/drm/meson/meson_dw_hdmi.c | 85 +++++++++++++++++++++------
 1 file changed, 68 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 38316c6cac26..10223aa27f7c 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -148,6 +148,7 @@ struct meson_dw_hdmi {
 	struct regulator *hdmi_supply;
 	u32 irq_stat;
 	struct dw_hdmi *hdmi;
+	unsigned long output_bus_fmt;
 };
 #define encoder_to_meson_dw_hdmi(x) \
 	container_of(x, struct meson_dw_hdmi, encoder)
@@ -297,6 +298,10 @@ static void meson_hdmi_phy_setup_mode(struct meson_dw_hdmi *dw_hdmi,
 	struct meson_drm *priv = dw_hdmi->priv;
 	unsigned int pixel_clock = mode->clock;
 
+	/* For 420, pixel clock is half unlike venc clock */
+	if (dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24)
+		pixel_clock /= 2;
+
 	if (dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxl-dw-hdmi") ||
 	    dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxm-dw-hdmi")) {
 		if (pixel_clock >= 371250) {
@@ -379,6 +384,10 @@ static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
 
 	vclk_freq = mode->clock;
 
+	/* For 420, pixel clock is half unlike venc clock */
+	if (dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24)
+		vclk_freq /= 2;
+
 	/* TMDS clock is pixel_clock * 10 */
 	phy_freq = vclk_freq * 10;
 
@@ -388,13 +397,16 @@ static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
 		return;
 	}
 
+	/* 480i/576i needs global pixel doubling */
 	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		vclk_freq *= 2;
 
 	venc_freq = vclk_freq;
 	hdmi_freq = vclk_freq;
 
-	if (meson_venc_hdmi_venc_repeat(vic))
+	/* VENC double pixels for 1080i, 720p and YUV420 modes */
+	if (meson_venc_hdmi_venc_repeat(vic) ||
+	    dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24)
 		venc_freq *= 2;
 
 	vclk_freq = max(venc_freq, hdmi_freq);
@@ -441,8 +453,9 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
 	/* Enable normal output to PHY */
 	dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_BIST_CNTL, BIT(12));
 
-	/* TMDS pattern setup (TOFIX Handle the YUV420 case) */
-	if (mode->clock > 340000) {
+	/* TMDS pattern setup */
+	if (mode->clock > 340000 &&
+	    dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_YUV8_1X24) {
 		dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01,
 				  0);
 		dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_23,
@@ -617,6 +630,7 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 		   const struct drm_display_mode *mode)
 {
 	struct meson_drm *priv = connector->dev->dev_private;
+	bool is_hdmi2_sink = connector->display_info.hdmi.scdc.supported;
 	unsigned int phy_freq;
 	unsigned int vclk_freq;
 	unsigned int venc_freq;
@@ -626,9 +640,11 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 	DRM_DEBUG_DRIVER("Modeline " DRM_MODE_FMT "\n", DRM_MODE_ARG(mode));
 
-	/* If sink max TMDS clock, we reject the mode */
+	/* If sink does not support 540MHz, reject the non-420 HDMI2 modes */
 	if (connector->display_info.max_tmds_clock &&
-	    mode->clock > connector->display_info.max_tmds_clock)
+	    mode->clock > connector->display_info.max_tmds_clock &&
+	    !drm_mode_is_420_only(&connector->display_info, mode) &&
+	    !drm_mode_is_420_also(&connector->display_info, mode))
 		return MODE_BAD;
 
 	/* Check against non-VIC supported modes */
@@ -644,6 +660,12 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 	vclk_freq = mode->clock;
 
+	/* For 420, pixel clock is half unlike venc clock */
+	if (drm_mode_is_420_only(&connector->display_info, mode) ||
+	    (!is_hdmi2_sink &&
+	     drm_mode_is_420_also(&connector->display_info, mode)))
+		vclk_freq /= 2;
+
 	/* TMDS clock is pixel_clock * 10 */
 	phy_freq = vclk_freq * 10;
 
@@ -654,8 +676,11 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 	venc_freq = vclk_freq;
 	hdmi_freq = vclk_freq;
 
-	/* VENC double pixels for 1080i and 720p modes */
-	if (meson_venc_hdmi_venc_repeat(vic))
+	/* VENC double pixels for 1080i, 720p and YUV420 modes */
+	if (meson_venc_hdmi_venc_repeat(vic) ||
+	    drm_mode_is_420_only(&connector->display_info, mode) ||
+	    (!is_hdmi2_sink &&
+	     drm_mode_is_420_also(&connector->display_info, mode)))
 		venc_freq *= 2;
 
 	vclk_freq = max(venc_freq, hdmi_freq);
@@ -673,6 +698,7 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
 
 static const u32 meson_dw_hdmi_out_bus_fmts[] = {
 	MEDIA_BUS_FMT_YUV8_1X24,
+	MEDIA_BUS_FMT_UYYVYY8_0_5X24,
 };
 
 static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
@@ -708,13 +734,19 @@ meson_venc_hdmi_encoder_get_inp_bus_fmts(struct drm_bridge *bridge,
 					unsigned int *num_input_fmts,
 					u32 *input_fmts)
 {
-	if (output_fmt == meson_dw_hdmi_out_bus_fmts[0]) {
-		*num_input_fmts = 1;
-		if (input_fmts)
-			input_fmts[0] = output_fmt;
+	int i;
+
+	*num_input_fmts = 0;
+	
+	for (i = 0 ; i < ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts) ; ++i) {
+		if (output_fmt == meson_dw_hdmi_out_bus_fmts[i]) {
+			*num_input_fmts = 1;
+			if (input_fmts)
+				input_fmts[0] = output_fmt;
+
+			break;
+		}
 	}
-	else
-		*num_input_fmts = 0;
 }
 
 static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
@@ -722,6 +754,13 @@ static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
 					struct drm_crtc_state *crtc_state,
 					struct drm_connector_state *conn_state)
 {
+	struct drm_encoder *encoder = bridge_to_encoder(bridge);
+	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
+
+	dw_hdmi->output_bus_fmt = bridge_state->output_bus_cfg.fmt;
+
+	DRM_DEBUG_DRIVER("output_bus_fmt %lx\n", dw_hdmi->output_bus_fmt);
+
 	return 0;
 }
 
@@ -762,18 +801,29 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
 	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
 	struct meson_drm *priv = dw_hdmi->priv;
 	int vic = drm_match_cea_mode(mode);
+	unsigned int ycrcb_map = VPU_HDMI_OUTPUT_CBYCR;
+	bool yuv420_mode = false;
 
 	DRM_DEBUG_DRIVER("\"%s\" vic %d\n", mode->name, vic);
 
+	if (dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24) {
+		ycrcb_map = VPU_HDMI_OUTPUT_CRYCB;
+		yuv420_mode = true;
+	}
+
 	/* VENC + VENC-DVI Mode setup */
-	meson_venc_hdmi_mode_set(priv, vic, ycrcb_map, false,
-				 VPU_HDMI_OUTPUT_CBYCR);
+	meson_venc_hdmi_mode_set(priv, vic, ycrcb_map, yuv420_mode, mode);
 
 	/* VCLK Set clock */
 	dw_hdmi_set_vclk(dw_hdmi, mode);
 
-	/* Setup YUV444 to HDMI-TX, no 10bit diphering */
-	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
+	if (dw_hdmi->output_bus_fmt == MEDIA_BUS_FMT_UYYVYY8_0_5X24)
+		/* Setup YUV420 to HDMI-TX, no 10bit diphering */
+		writel_relaxed(2 | (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));
 }
 
 static const struct drm_bridge_funcs meson_venc_hdmi_encoder_bridge_funcs = {
@@ -1017,6 +1067,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
 	dw_plat_data->phy_name = "meson_dw_hdmi_phy";
 	dw_plat_data->phy_data = meson_dw_hdmi;
 	dw_plat_data->input_bus_encoding = V4L2_YCBCR_ENC_709;
+	dw_plat_data->ycbcr_420_allowed = true;
 
 	platform_set_drvdata(pdev, meson_dw_hdmi);
 
-- 
2.22.0

Re: [PATCH RFC v2 2/8] drm/meson: meson_dw_hdmi: switch to drm_bridge_funcs

[Boris Brezillon]

On Tue, 27 Aug 2019 10:14:19 +0200
Neil Armstrong <narmstrong@baylibre.com> wrote:

> Switch the dw-hdmi driver to drm_bridge_funcs, and implement the
> atomic_get_input_bus_fmts/atomic_get_output_bus_fmts.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/gpu/drm/meson/meson_dw_hdmi.c | 67 +++++++++++++++++++++------
>  1 file changed, 54 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index f893ebd0b799..333583ef3ab9 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -368,7 +368,7 @@ static inline void meson_dw_hdmi_phy_reset(struct meson_dw_hdmi *dw_hdmi)
>  }
>  
>  static void dw_hdmi_set_vclk(struct meson_dw_hdmi *dw_hdmi,
> -			     struct drm_display_mode *mode)
> +			     const struct drm_display_mode *mode)
>  {
>  	struct meson_drm *priv = dw_hdmi->priv;
>  	int vic = drm_match_cea_mode(mode);
> @@ -663,6 +663,10 @@ dw_hdmi_mode_valid(struct drm_connector *connector,
>  
>  /* Encoder */
>  
> +static const u32 meson_dw_hdmi_out_bus_fmts[] = {
> +	MEDIA_BUS_FMT_YUV8_1X24,
> +};
> +
>  static void meson_venc_hdmi_encoder_destroy(struct drm_encoder *encoder)
>  {
>  	drm_encoder_cleanup(encoder);
> @@ -672,15 +676,50 @@ static const struct drm_encoder_funcs meson_venc_hdmi_encoder_funcs = {
>  	.destroy        = meson_venc_hdmi_encoder_destroy,
>  };
>  
> -static int meson_venc_hdmi_encoder_atomic_check(struct drm_encoder *encoder,
> +static void
> +meson_venc_hdmi_encoder_get_out_bus_fmts(struct drm_bridge *bridge,
> +					 struct drm_bridge_state *bridge_state,
> +					 struct drm_crtc_state *crtc_state,
> +					 struct drm_connector_state *conn_state,
> +					 unsigned int *num_output_fmts,
> +					 u32 *output_fmts)
> +{
> +	*num_output_fmts = ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts);
> +
> +	if (output_fmts)
> +		memcpy(output_fmts, meson_dw_hdmi_out_bus_fmts,
> +		       ARRAY_SIZE(meson_dw_hdmi_out_bus_fmts));
> +}
> +
> +static void
> +meson_venc_hdmi_encoder_get_inp_bus_fmts(struct drm_bridge *bridge,
> +					struct drm_bridge_state *bridge_state,
> +					struct drm_crtc_state *crtc_state,
> +					struct drm_connector_state *conn_state,
> +					u32 output_fmt,
> +					unsigned int *num_input_fmts,
> +					u32 *input_fmts)
> +{
> +	if (output_fmt == meson_dw_hdmi_out_bus_fmts[0]) {
> +		*num_input_fmts = 1;
> +		if (input_fmts)
> +			input_fmts[0] = output_fmt;
> +	}
> +	else
> +		*num_input_fmts = 0;

nitpick:

	} else {
		*num_input_fmts = 0;
	}

> +}
> +
> +static int meson_venc_hdmi_encoder_atomic_check(struct drm_bridge *bridge,
> +					struct drm_bridge_state *bridge_state,
>  					struct drm_crtc_state *crtc_state,
>  					struct drm_connector_state *conn_state)
>  {
>  	return 0;
>  }

This hook is optional, you don't need this stub.

Looks good otherwise:

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

>  
> -static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
> +static void meson_venc_hdmi_encoder_disable(struct drm_bridge *bridge)
>  {
> +	struct drm_encoder *encoder = bridge_to_encoder(bridge);
>  	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>  	struct meson_drm *priv = dw_hdmi->priv;
>  
> @@ -693,8 +732,9 @@ static void meson_venc_hdmi_encoder_disable(struct drm_encoder *encoder)
>  	writel_relaxed(0, priv->io_base + _REG(ENCP_VIDEO_EN));
>  }
>  
> -static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
> +static void meson_venc_hdmi_encoder_enable(struct drm_bridge *bridge)
>  {
> +	struct drm_encoder *encoder = bridge_to_encoder(bridge);
>  	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>  	struct meson_drm *priv = dw_hdmi->priv;
>  
> @@ -706,10 +746,11 @@ static void meson_venc_hdmi_encoder_enable(struct drm_encoder *encoder)
>  		writel_relaxed(1, priv->io_base + _REG(ENCP_VIDEO_EN));
>  }
>  
> -static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
> -				   struct drm_display_mode *mode,
> -				   struct drm_display_mode *adjusted_mode)
> +static void meson_venc_hdmi_encoder_mode_set(struct drm_bridge *bridge,
> +				   const struct drm_display_mode *mode,
> +				   const struct drm_display_mode *adjusted_mode)
>  {
> +	struct drm_encoder *encoder = bridge_to_encoder(bridge);
>  	struct meson_dw_hdmi *dw_hdmi = encoder_to_meson_dw_hdmi(encoder);
>  	struct meson_drm *priv = dw_hdmi->priv;
>  	int vic = drm_match_cea_mode(mode);
> @@ -726,11 +767,12 @@ static void meson_venc_hdmi_encoder_mode_set(struct drm_encoder *encoder,
>  	writel_relaxed(0, priv->io_base + _REG(VPU_HDMI_FMT_CTRL));
>  }
>  
> -static const struct drm_encoder_helper_funcs
> -				meson_venc_hdmi_encoder_helper_funcs = {
> -	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
> -	.disable	= meson_venc_hdmi_encoder_disable,
> +static const struct drm_bridge_funcs meson_venc_hdmi_encoder_bridge_funcs = {
>  	.enable		= meson_venc_hdmi_encoder_enable,
> +	.disable	= meson_venc_hdmi_encoder_disable,
> +	.atomic_check	= meson_venc_hdmi_encoder_atomic_check,
> +	.atomic_get_output_bus_fmts = meson_venc_hdmi_encoder_get_out_bus_fmts,
> +	.atomic_get_input_bus_fmts = meson_venc_hdmi_encoder_get_inp_bus_fmts,
>  	.mode_set	= meson_venc_hdmi_encoder_mode_set,
>  };
>  
> @@ -912,8 +954,7 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>  
>  	/* Encoder */
>  
> -	drm_encoder_helper_add(encoder, &meson_venc_hdmi_encoder_helper_funcs);
> -
> +	encoder->bridge.funcs = &meson_venc_hdmi_encoder_bridge_funcs;
>  	ret = drm_encoder_init(drm, encoder, &meson_venc_hdmi_encoder_funcs,
>  			       DRM_MODE_ENCODER_TMDS, "meson_hdmi");
>  	if (ret) {

Re: [PATCH RFC v2 3/8] drm/bridge: synopsys: dw-hdmi: add bus format negociation

[Boris Brezillon]

On Tue, 27 Aug 2019 10:14:20 +0200
Neil Armstrong <narmstrong@baylibre.com> wrote:

> Add the atomic_get_output_bus_fmts, atomic_get_input_bus_fmts to negociate

								   ^negotiate

> the possible output and input formats for the current mode and monitor,
> and use the negociated formats in a basic atomic_check callback.

	      ^negotiated

> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---


>  
> +static void dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
> +					struct drm_bridge_state *bridge_state,
> +					struct drm_crtc_state *crtc_state,
> +					struct drm_connector_state *conn_state,
> +					unsigned int *num_output_fmts,
> +					u32 *output_fmts)
> +{
> +	struct drm_connector *conn = conn_state->connector;
> +	struct drm_display_info *info = &conn->display_info;
> +	struct drm_display_mode *mode = &crtc_state->mode;
> +	bool is_hdmi2_sink = info->hdmi.scdc.supported;	
> +	int i = 0;
> +
> +	/*
> +	 * If the current mode enforces 4:2:0, force the output but format
> +	 * to 4:2:0 and do not add the YUV422/444/RGB formats
> +	 */
> +	if (drm_mode_is_420_only(info, mode) ||
> +	    (!is_hdmi2_sink && drm_mode_is_420_also(info, mode))) {
> +
> +		/* Order bus formats from 16bit to 8bit if supported */
> +		if (info->bpc == 16 &&
> +		    (info->hdmi.y420_dc_modes & DRM_EDID_YCBCR420_DC_48)) {
> +			if (output_fmts)
> +				output_fmts[i] = MEDIA_BUS_FMT_UYYVYY16_0_5X48;
> +			++i;
> +		}

You could probably add the following helper:

static void dw_hdmi_bridge_add_fmt(unsigned int *num_fmts, u32 *fmts,
				   u32 new_fmt)
{
	if (fmts)
		fmts[*num_fmts] = new_fmt;

	(*num_fmts)++;
}

to avoid duplicating the

	if (fmts)
		...

	i++;			

logic.

Re: [PATCH RFC v2 4/8] drm/meson: dw-hdmi: stop enforcing input_bus_format

[Boris Brezillon]

On Tue, 27 Aug 2019 10:14:21 +0200
Neil Armstrong <narmstrong@baylibre.com> wrote:

> To allow using formats from negociation, stop enforcing input_bus_format

			      ^ negotiation

> in the private dw-plat-data struct.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/gpu/drm/meson/meson_dw_hdmi.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index 333583ef3ab9..9ae24cc5faa2 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -1007,7 +1007,6 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>  	dw_plat_data->phy_ops = &meson_dw_hdmi_phy_ops;
>  	dw_plat_data->phy_name = "meson_dw_hdmi_phy";
>  	dw_plat_data->phy_data = meson_dw_hdmi;
> -	dw_plat_data->input_bus_format = MEDIA_BUS_FMT_YUV8_1X24;
>  	dw_plat_data->input_bus_encoding = V4L2_YCBCR_ENC_709;
>  
>  	platform_set_drvdata(pdev, meson_dw_hdmi);

Re: [PATCH RFC v2 3/8] drm/bridge: synopsys: dw-hdmi: add bus format negociation

[Neil Armstrong]

On 27/08/2019 11:03, Boris Brezillon wrote:
> On Tue, 27 Aug 2019 10:14:20 +0200
> Neil Armstrong <narmstrong@baylibre.com> wrote:
> 
>> Add the atomic_get_output_bus_fmts, atomic_get_input_bus_fmts to negociate
> 
> 								   ^negotiate
> 
>> the possible output and input formats for the current mode and monitor,
>> and use the negociated formats in a basic atomic_check callback.
> 
> 	      ^negotiated

Indeed, thx

> 
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
> 
> 
>>  
>> +static void dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
>> +					struct drm_bridge_state *bridge_state,
>> +					struct drm_crtc_state *crtc_state,
>> +					struct drm_connector_state *conn_state,
>> +					unsigned int *num_output_fmts,
>> +					u32 *output_fmts)
>> +{
>> +	struct drm_connector *conn = conn_state->connector;
>> +	struct drm_display_info *info = &conn->display_info;
>> +	struct drm_display_mode *mode = &crtc_state->mode;
>> +	bool is_hdmi2_sink = info->hdmi.scdc.supported;	
>> +	int i = 0;
>> +
>> +	/*
>> +	 * If the current mode enforces 4:2:0, force the output but format
>> +	 * to 4:2:0 and do not add the YUV422/444/RGB formats
>> +	 */
>> +	if (drm_mode_is_420_only(info, mode) ||
>> +	    (!is_hdmi2_sink && drm_mode_is_420_also(info, mode))) {
>> +
>> +		/* Order bus formats from 16bit to 8bit if supported */
>> +		if (info->bpc == 16 &&
>> +		    (info->hdmi.y420_dc_modes & DRM_EDID_YCBCR420_DC_48)) {
>> +			if (output_fmts)
>> +				output_fmts[i] = MEDIA_BUS_FMT_UYYVYY16_0_5X48;
>> +			++i;
>> +		}
> 
> You could probably add the following helper:
> 
> static void dw_hdmi_bridge_add_fmt(unsigned int *num_fmts, u32 *fmts,
> 				   u32 new_fmt)
> {
> 	if (fmts)
> 		fmts[*num_fmts] = new_fmt;
> 
> 	(*num_fmts)++;
> }
> 
> to avoid duplicating the
> 
> 	if (fmts)
> 		...
> 
> 	i++;			
> 
> logic.
> 

Yes, I was planning this,

Thanks,
Neil