drm/i915/dp: Program an Infoframe SDP Header and DB for HDR Static Metadata

Function intel_dp_setup_hdr_metadata_infoframe_sdp handles Infoframe SDP
header and data block setup for HDR Static Metadata. It enables writing of
HDR metadata infoframe SDP to panel. Support for HDR video was introduced
in DisplayPort 1.4. It implements the CTA-861-G standard for transport of
static HDR metadata. The HDR Metadata will be provided by userspace
compositors, based on blending policies and passed to the driver through
a blob property.

Because each of GEN11 and prior GEN11 have different register size for
HDR Metadata Infoframe SDP packet, it adds and uses different register
size.

Setup Infoframe SDP header and data block in function
intel_dp_setup_hdr_metadata_infoframe_sdp for HDR Static Metadata as per
dp 1.4 spec and CTA-861-F spec.
As per DP 1.4 spec, 2.2.2.5 SDP Formats. It enables Dynamic Range and
Mastering Infoframe for HDR content, which is defined in CTA-861-F spec.
According to DP 1.4 spec and CEA-861-F spec Table 5, in order to transmit
static HDR metadata, we have to use Non-audio INFOFRAME SDP v1.3.

+--------------------------------+-------------------------------+
|      [ Packet Type Value ]     |       [ Packet Type ]         |
+--------------------------------+-------------------------------+
| 80h + Non-audio INFOFRAME Type | CEA-861-F Non-audio INFOFRAME |
+--------------------------------+-------------------------------+
|      [Transmission Timing]                                     |
+----------------------------------------------------------------+
| As per CEA-861-F for INFOFRAME, including CEA-861.3 within     |
| which Dynamic Range and Mastering INFOFRAME are defined        |
+----------------------------------------------------------------+

v2: Add a missed blank line after function declaration.
v3: Remove not handled return values from
    intel_dp_setup_hdr_metadata_infoframe_sdp(). [Uma]
v9: Addressed review comments from Ville.
    - Add BUILD_BUG_ON to check a changing of struct dp_sdp size.
    - Change a passed size toward write_infoframe() for DP infoframe sdp
      packet for HDR static metadata.
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190919195311.13972-8-gwan-gyeong.mun@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -3856,6 +3856,7 @@ static void intel_enable_ddi_dp(struct intel_encoder *encoder,
 	intel_edp_backlight_on(crtc_state, conn_state);
 	intel_psr_enable(intel_dp, crtc_state);
 	intel_dp_vsc_enable(intel_dp, crtc_state, conn_state);
+	intel_dp_hdr_metadata_enable(intel_dp, crtc_state, conn_state);
 	intel_edp_drrs_enable(intel_dp, crtc_state);
 
 	if (crtc_state->has_audio)

drivers/gpu/drm/i915/display/intel_dp.c

@@ -4624,6 +4624,86 @@ intel_dp_setup_vsc_sdp(struct intel_dp *intel_dp,
 			crtc_state, DP_SDP_VSC, &vsc_sdp, sizeof(vsc_sdp));
 }
 
+static void
+intel_dp_setup_hdr_metadata_infoframe_sdp(struct intel_dp *intel_dp,
+					  const struct intel_crtc_state *crtc_state,
+					  const struct drm_connector_state *conn_state)
+{
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct dp_sdp infoframe_sdp = {};
+	struct hdmi_drm_infoframe drm_infoframe = {};
+	const int infoframe_size = HDMI_INFOFRAME_HEADER_SIZE + HDMI_DRM_INFOFRAME_SIZE;
+	unsigned char buf[HDMI_INFOFRAME_HEADER_SIZE + HDMI_DRM_INFOFRAME_SIZE];
+	ssize_t len;
+	int ret;
+
+	ret = drm_hdmi_infoframe_set_hdr_metadata(&drm_infoframe, conn_state);
+	if (ret) {
+		DRM_DEBUG_KMS("couldn't set HDR metadata in infoframe\n");
+		return;
+	}
+
+	len = hdmi_drm_infoframe_pack_only(&drm_infoframe, buf, sizeof(buf));
+	if (len < 0) {
+		DRM_DEBUG_KMS("buffer size is smaller than hdr metadata infoframe\n");
+		return;
+	}
+
+	if (len != infoframe_size) {
+		DRM_DEBUG_KMS("wrong static hdr metadata size\n");
+		return;
+	}
+
+	/*
+	 * Set up the infoframe sdp packet for HDR static metadata.
+	 * Prepare VSC Header for SU as per DP 1.4a spec,
+	 * Table 2-100 and Table 2-101
+	 */
+
+	/* Packet ID, 00h for non-Audio INFOFRAME */
+	infoframe_sdp.sdp_header.HB0 = 0;
+	/*
+	 * Packet Type 80h + Non-audio INFOFRAME Type value
+	 * HDMI_INFOFRAME_TYPE_DRM: 0x87,
+	 */
+	infoframe_sdp.sdp_header.HB1 = drm_infoframe.type;
+	/*
+	 * Least Significant Eight Bits of (Data Byte Count – 1)
+	 * infoframe_size - 1,
+	 */
+	infoframe_sdp.sdp_header.HB2 = 0x1D;
+	/* INFOFRAME SDP Version Number */
+	infoframe_sdp.sdp_header.HB3 = (0x13 << 2);
+	/* CTA Header Byte 2 (INFOFRAME Version Number) */
+	infoframe_sdp.db[0] = drm_infoframe.version;
+	/* CTA Header Byte 3 (Length of INFOFRAME): HDMI_DRM_INFOFRAME_SIZE */
+	infoframe_sdp.db[1] = drm_infoframe.length;
+	/*
+	 * Copy HDMI_DRM_INFOFRAME_SIZE size from a buffer after
+	 * HDMI_INFOFRAME_HEADER_SIZE
+	 */
+	BUILD_BUG_ON(sizeof(infoframe_sdp.db) < HDMI_DRM_INFOFRAME_SIZE + 2);
+	memcpy(&infoframe_sdp.db[2], &buf[HDMI_INFOFRAME_HEADER_SIZE],
+	       HDMI_DRM_INFOFRAME_SIZE);
+
+	/*
+	 * Size of DP infoframe sdp packet for HDR static metadata is consist of
+	 * - DP SDP Header(struct dp_sdp_header): 4 bytes
+	 * - Two Data Blocks: 2 bytes
+	 *    CTA Header Byte2 (INFOFRAME Version Number)
+	 *    CTA Header Byte3 (Length of INFOFRAME)
+	 * - HDMI_DRM_INFOFRAME_SIZE: 26 bytes
+	 *
+	 * Prior to GEN11's GMP register size is identical to DP HDR static metadata
+	 * infoframe size. But GEN11+ has larger than that size, write_infoframe
+	 * will pad rest of the size.
+	 */
+	intel_dig_port->write_infoframe(&intel_dig_port->base, crtc_state,
+					HDMI_PACKET_TYPE_GAMUT_METADATA,
+					&infoframe_sdp,
+					sizeof(struct dp_sdp_header) + 2 + HDMI_DRM_INFOFRAME_SIZE);
+}
+
 void intel_dp_vsc_enable(struct intel_dp *intel_dp,
 			 const struct intel_crtc_state *crtc_state,
 			 const struct drm_connector_state *conn_state)
@@ -4634,6 +4714,18 @@ void intel_dp_vsc_enable(struct intel_dp *intel_dp,
 	intel_dp_setup_vsc_sdp(intel_dp, crtc_state, conn_state);
 }
 
+void intel_dp_hdr_metadata_enable(struct intel_dp *intel_dp,
+				  const struct intel_crtc_state *crtc_state,
+				  const struct drm_connector_state *conn_state)
+{
+	if (!conn_state->hdr_output_metadata)
+		return;
+
+	intel_dp_setup_hdr_metadata_infoframe_sdp(intel_dp,
+						  crtc_state,
+						  conn_state);
+}
+
 static u8 intel_dp_autotest_link_training(struct intel_dp *intel_dp)
 {
 	int status = 0;

drivers/gpu/drm/i915/display/intel_dp.h

@@ -113,6 +113,9 @@ bool intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
 void intel_dp_vsc_enable(struct intel_dp *intel_dp,
 			 const struct intel_crtc_state *crtc_state,
 			 const struct drm_connector_state *conn_state);
+void intel_dp_hdr_metadata_enable(struct intel_dp *intel_dp,
+				  const struct intel_crtc_state *crtc_state,
+				  const struct drm_connector_state *conn_state);
 bool intel_digital_port_connected(struct intel_encoder *encoder);
 
 static inline unsigned int intel_dp_unused_lane_mask(int lane_count)