drm/i915/dp: Populate DSC PPS SDP and send PPS infoframes

DSC PPS secondary data packet infoframes are filled with
DSC picure parameter set metadata according to the DSC standard.
These infoframes are sent to the sink device and used during DSC
decoding.

v3:
* Rename to intel_dp_write_pps_sdp (Ville)
* Use const intel_crtc_state (Ville)
v2:
* Rebase ond drm-tip

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181128202628.20238-10-manasi.d.navare@intel.com

drivers/gpu/drm/i915/intel_vdsc.c

@@ -978,6 +978,25 @@ static void intel_configure_pps_for_dsc_encoder(struct intel_encoder *encoder,
 	}
 }
 
+static void intel_dp_write_dsc_pps_sdp(struct intel_encoder *encoder,
+				       const struct intel_crtc_state *crtc_state)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	const struct drm_dsc_config *vdsc_cfg = &crtc_state->dp_dsc_cfg;
+	struct drm_dsc_pps_infoframe dp_dsc_pps_sdp;
+
+	/* Prepare DP SDP PPS header as per DP 1.4 spec, Table 2-123 */
+	drm_dsc_dp_pps_header_init(&dp_dsc_pps_sdp);
+
+	/* Fill the PPS payload bytes as per DSC spec 1.2 Table 4-1 */
+	drm_dsc_pps_infoframe_pack(&dp_dsc_pps_sdp, vdsc_cfg);
+
+	intel_dig_port->write_infoframe(encoder, crtc_state,
+					DP_SDP_PPS, &dp_dsc_pps_sdp,
+					sizeof(dp_dsc_pps_sdp));
+}
+
 void intel_dsc_enable(struct intel_encoder *encoder,
 		      const struct intel_crtc_state *crtc_state)
 {
@@ -985,4 +1004,6 @@ void intel_dsc_enable(struct intel_encoder *encoder,
 		return;
 
 	intel_configure_pps_for_dsc_encoder(encoder, crtc_state);
+
+	intel_dp_write_dsc_pps_sdp(encoder, crtc_state);
 }