drm/dsc: Split DSC PPS and SDP header initialisations

The DP 1.4 spec defines the SDP header and SDP contents for
a Picture Parameter Set (PPS) that must be sent in advance
of DSC transmission to define the encoding characteristics.

This was done in one struct, drm_dsc_pps_infoframe, which
conatined the SDP header and PPS. Because the PPS is
a property of DSC over any connector, not just DP, and because
drm drivers may have their own SDP structs they wish to use,
make the functions that initialise SDP and PPS headers take
the components they operate on, not drm_dsc_pps_infoframe,

Signed-off-by: David Francis <[e-mail]>
Reviewed-by: Manasi Navare <[e-mail]>
Signed-off-by: Harry Wentland <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_dsc.c

···
 /**
  * drm_dsc_dp_pps_header_init() - Initializes the PPS Header
  * for DisplayPort as per the DP 1.4 spec.
- * @pps_sdp: Secondary data packet for DSC Picture Parameter Set
- *           as defined in &struct drm_dsc_pps_infoframe
+ * @pps_header: Secondary data packet header for DSC Picture
+ *              Parameter Set as defined in &struct dp_sdp_header
  *
  * DP 1.4 spec defines the secondary data packet for sending the
  * picture parameter infoframes from the source to the sink.
- * This function populates the pps header defined in
- * &struct drm_dsc_pps_infoframe as per the header bytes defined
- * in &struct dp_sdp_header.
+ * This function populates the SDP header defined in
+ * &struct dp_sdp_header.
  */
-void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp)
+void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header)
 {
-	memset(&pps_sdp->pps_header, 0, sizeof(pps_sdp->pps_header));
+	memset(pps_header, 0, sizeof(*pps_header));
 
-	pps_sdp->pps_header.HB1 = DP_SDP_PPS;
-	pps_sdp->pps_header.HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
+	pps_header->HB1 = DP_SDP_PPS;
+	pps_header->HB2 = DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1;
 }
 EXPORT_SYMBOL(drm_dsc_dp_pps_header_init);
 
 /**
- * drm_dsc_pps_infoframe_pack() - Populates the DSC PPS infoframe
+ * drm_dsc_pps_payload_pack() - Populates the DSC PPS
  *
- * @pps_sdp:
- * Secondary data packet for DSC Picture Parameter Set. This is defined
- * by &struct drm_dsc_pps_infoframe
+ * @pps_payload:
+ * Bitwise struct for DSC Picture Parameter Set. This is defined
+ * by &struct drm_dsc_picture_parameter_set
  * @dsc_cfg:
  * DSC Configuration data filled by driver as defined by
  * &struct drm_dsc_config
  *
- * DSC source device sends a secondary data packet filled with all the
- * picture parameter set (PPS) information required by the sink to decode
- * the compressed frame. Driver populates the dsC PPS infoframe using the DSC
- * configuration parameters in the order expected by the DSC Display Sink
- * device. For the DSC, the sink device expects the PPS payload in the big
- * endian format for the fields that span more than 1 byte.
+ * DSC source device sends a picture parameter set (PPS) containing the
+ * information required by the sink to decode the compressed frame. Driver
+ * populates the DSC PPS struct using the DSC configuration parameters in
+ * the order expected by the DSC Display Sink device. For the DSC, the sink
+ * device expects the PPS payload in big endian format for fields
+ * that span more than 1 byte.
  */
-void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_payload,
 				const struct drm_dsc_config *dsc_cfg)
 {
 	int i;
 
 	/* Protect against someone accidently changing struct size */
-	BUILD_BUG_ON(sizeof(pps_sdp->pps_payload) !=
+	BUILD_BUG_ON(sizeof(*pps_payload) !=
 		     DP_SDP_PPS_HEADER_PAYLOAD_BYTES_MINUS_1 + 1);
 
-	memset(&pps_sdp->pps_payload, 0, sizeof(pps_sdp->pps_payload));
+	memset(pps_payload, 0, sizeof(*pps_payload));
 
 	/* PPS 0 */
-	pps_sdp->pps_payload.dsc_version =
+	pps_payload->dsc_version =
 		dsc_cfg->dsc_version_minor |
 		dsc_cfg->dsc_version_major << DSC_PPS_VERSION_MAJOR_SHIFT;
 
 	/* PPS 1, 2 is 0 */
 
 	/* PPS 3 */
-	pps_sdp->pps_payload.pps_3 =
+	pps_payload->pps_3 =
 		dsc_cfg->line_buf_depth |
 		dsc_cfg->bits_per_component << DSC_PPS_BPC_SHIFT;
 
 	/* PPS 4 */
-	pps_sdp->pps_payload.pps_4 =
+	pps_payload->pps_4 =
 		((dsc_cfg->bits_per_pixel & DSC_PPS_BPP_HIGH_MASK) >>
 		 DSC_PPS_MSB_SHIFT) |
 		dsc_cfg->vbr_enable << DSC_PPS_VBR_EN_SHIFT |
···
 		dsc_cfg->block_pred_enable << DSC_PPS_BLOCK_PRED_EN_SHIFT;
 
 	/* PPS 5 */
-	pps_sdp->pps_payload.bits_per_pixel_low =
+	pps_payload->bits_per_pixel_low =
 		(dsc_cfg->bits_per_pixel & DSC_PPS_LSB_MASK);
 
 	/*
···
 	 */
 
 	/* PPS 6, 7 */
-	pps_sdp->pps_payload.pic_height = cpu_to_be16(dsc_cfg->pic_height);
+	pps_payload->pic_height = cpu_to_be16(dsc_cfg->pic_height);
 
 	/* PPS 8, 9 */
-	pps_sdp->pps_payload.pic_width = cpu_to_be16(dsc_cfg->pic_width);
+	pps_payload->pic_width = cpu_to_be16(dsc_cfg->pic_width);
 
 	/* PPS 10, 11 */
-	pps_sdp->pps_payload.slice_height = cpu_to_be16(dsc_cfg->slice_height);
+	pps_payload->slice_height = cpu_to_be16(dsc_cfg->slice_height);
 
 	/* PPS 12, 13 */
-	pps_sdp->pps_payload.slice_width = cpu_to_be16(dsc_cfg->slice_width);
+	pps_payload->slice_width = cpu_to_be16(dsc_cfg->slice_width);
 
 	/* PPS 14, 15 */
-	pps_sdp->pps_payload.chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
+	pps_payload->chunk_size = cpu_to_be16(dsc_cfg->slice_chunk_size);
 
 	/* PPS 16 */
-	pps_sdp->pps_payload.initial_xmit_delay_high =
+	pps_payload->initial_xmit_delay_high =
 		((dsc_cfg->initial_xmit_delay &
 		  DSC_PPS_INIT_XMIT_DELAY_HIGH_MASK) >>
 		 DSC_PPS_MSB_SHIFT);
 
 	/* PPS 17 */
-	pps_sdp->pps_payload.initial_xmit_delay_low =
+	pps_payload->initial_xmit_delay_low =
 		(dsc_cfg->initial_xmit_delay & DSC_PPS_LSB_MASK);
 
 	/* PPS 18, 19 */
-	pps_sdp->pps_payload.initial_dec_delay =
+	pps_payload->initial_dec_delay =
 		cpu_to_be16(dsc_cfg->initial_dec_delay);
 
 	/* PPS 20 is 0 */
 
 	/* PPS 21 */
-	pps_sdp->pps_payload.initial_scale_value =
+	pps_payload->initial_scale_value =
 		dsc_cfg->initial_scale_value;
 
 	/* PPS 22, 23 */
-	pps_sdp->pps_payload.scale_increment_interval =
+	pps_payload->scale_increment_interval =
 		cpu_to_be16(dsc_cfg->scale_increment_interval);
 
 	/* PPS 24 */
-	pps_sdp->pps_payload.scale_decrement_interval_high =
+	pps_payload->scale_decrement_interval_high =
 		((dsc_cfg->scale_decrement_interval &
 		  DSC_PPS_SCALE_DEC_INT_HIGH_MASK) >>
 		 DSC_PPS_MSB_SHIFT);
 
 	/* PPS 25 */
-	pps_sdp->pps_payload.scale_decrement_interval_low =
+	pps_payload->scale_decrement_interval_low =
 		(dsc_cfg->scale_decrement_interval & DSC_PPS_LSB_MASK);
 
 	/* PPS 26[7:0], PPS 27[7:5] RESERVED */
 
 	/* PPS 27 */
-	pps_sdp->pps_payload.first_line_bpg_offset =
+	pps_payload->first_line_bpg_offset =
 		dsc_cfg->first_line_bpg_offset;
 
 	/* PPS 28, 29 */
-	pps_sdp->pps_payload.nfl_bpg_offset =
+	pps_payload->nfl_bpg_offset =
 		cpu_to_be16(dsc_cfg->nfl_bpg_offset);
 
 	/* PPS 30, 31 */
-	pps_sdp->pps_payload.slice_bpg_offset =
+	pps_payload->slice_bpg_offset =
 		cpu_to_be16(dsc_cfg->slice_bpg_offset);
 
 	/* PPS 32, 33 */
-	pps_sdp->pps_payload.initial_offset =
+	pps_payload->initial_offset =
 		cpu_to_be16(dsc_cfg->initial_offset);
 
 	/* PPS 34, 35 */
-	pps_sdp->pps_payload.final_offset = cpu_to_be16(dsc_cfg->final_offset);
+	pps_payload->final_offset = cpu_to_be16(dsc_cfg->final_offset);
 
 	/* PPS 36 */
-	pps_sdp->pps_payload.flatness_min_qp = dsc_cfg->flatness_min_qp;
+	pps_payload->flatness_min_qp = dsc_cfg->flatness_min_qp;
 
 	/* PPS 37 */
-	pps_sdp->pps_payload.flatness_max_qp = dsc_cfg->flatness_max_qp;
+	pps_payload->flatness_max_qp = dsc_cfg->flatness_max_qp;
 
 	/* PPS 38, 39 */
-	pps_sdp->pps_payload.rc_model_size =
+	pps_payload->rc_model_size =
 		cpu_to_be16(DSC_RC_MODEL_SIZE_CONST);
 
 	/* PPS 40 */
-	pps_sdp->pps_payload.rc_edge_factor = DSC_RC_EDGE_FACTOR_CONST;
+	pps_payload->rc_edge_factor = DSC_RC_EDGE_FACTOR_CONST;
 
 	/* PPS 41 */
-	pps_sdp->pps_payload.rc_quant_incr_limit0 =
+	pps_payload->rc_quant_incr_limit0 =
 		dsc_cfg->rc_quant_incr_limit0;
 
 	/* PPS 42 */
-	pps_sdp->pps_payload.rc_quant_incr_limit1 =
+	pps_payload->rc_quant_incr_limit1 =
 		dsc_cfg->rc_quant_incr_limit1;
 
 	/* PPS 43 */
-	pps_sdp->pps_payload.rc_tgt_offset = DSC_RC_TGT_OFFSET_LO_CONST |
+	pps_payload->rc_tgt_offset = DSC_RC_TGT_OFFSET_LO_CONST |
 		DSC_RC_TGT_OFFSET_HI_CONST << DSC_PPS_RC_TGT_OFFSET_HI_SHIFT;
 
 	/* PPS 44 - 57 */
 	for (i = 0; i < DSC_NUM_BUF_RANGES - 1; i++)
-		pps_sdp->pps_payload.rc_buf_thresh[i] =
+		pps_payload->rc_buf_thresh[i] =
 			dsc_cfg->rc_buf_thresh[i];
 
 	/* PPS 58 - 87 */
···
 	 * are as follows: Min_qp[15:11], max_qp[10:6], offset[5:0]
 	 */
 	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
-		pps_sdp->pps_payload.rc_range_parameters[i] =
+		pps_payload->rc_range_parameters[i] =
 			((dsc_cfg->rc_range_params[i].range_min_qp <<
 			  DSC_PPS_RC_RANGE_MINQP_SHIFT) |
 			 (dsc_cfg->rc_range_params[i].range_max_qp <<
 			  DSC_PPS_RC_RANGE_MAXQP_SHIFT) |
 			 (dsc_cfg->rc_range_params[i].range_bpg_offset));
-		pps_sdp->pps_payload.rc_range_parameters[i] =
-			cpu_to_be16(pps_sdp->pps_payload.rc_range_parameters[i]);
+		pps_payload->rc_range_parameters[i] =
+			cpu_to_be16(pps_payload->rc_range_parameters[i]);
 	}
 
 	/* PPS 88 */
-	pps_sdp->pps_payload.native_422_420 = dsc_cfg->native_422 |
+	pps_payload->native_422_420 = dsc_cfg->native_422 |
 		dsc_cfg->native_420 << DSC_PPS_NATIVE_420_SHIFT;
 
 	/* PPS 89 */
-	pps_sdp->pps_payload.second_line_bpg_offset =
+	pps_payload->second_line_bpg_offset =
 		dsc_cfg->second_line_bpg_offset;
 
 	/* PPS 90, 91 */
-	pps_sdp->pps_payload.nsl_bpg_offset =
+	pps_payload->nsl_bpg_offset =
 		cpu_to_be16(dsc_cfg->nsl_bpg_offset);
 
 	/* PPS 92, 93 */
-	pps_sdp->pps_payload.second_line_offset_adj =
+	pps_payload->second_line_offset_adj =
 		cpu_to_be16(dsc_cfg->second_line_offset_adj);
 
 	/* PPS 94 - 127 are O */
 }
-EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
+EXPORT_SYMBOL(drm_dsc_pps_payload_pack);
 
 /**
  * drm_dsc_compute_rc_parameters() - Write rate control

drivers/gpu/drm/i915/intel_vdsc.c

···
 	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);
+	drm_dsc_dp_pps_header_init(&dp_dsc_pps_sdp.pps_header);
 
 	/* 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);
+	drm_dsc_pps_payload_pack(&dp_dsc_pps_sdp.pps_payload, vdsc_cfg);
 
 	intel_dig_port->write_infoframe(encoder, crtc_state,
 					DP_SDP_PPS, &dp_dsc_pps_sdp,

include/drm/drm_dsc.h

···
 	struct drm_dsc_picture_parameter_set pps_payload;
 } __packed;
 
-void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
-void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
+void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header);
+void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_sdp,
 				const struct drm_dsc_config *dsc_cfg);
 int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg);