[RFC 11/13] drm/i915: Read DSC capabilities of the HDMI2.1 PCON encoder

Ankit Nautiyal ankit.k.nautiyal at intel.com
Thu Oct 15 10:52:57 UTC 2020


This patch adds a helper function to read the DSC capabilities of the
HDMI2.1 PCon encoder. It also adds a new structure to store these caps,
which can then be used to get the PPS parameters for PCON-HDMI2.1 sink
pair. Which inturn will be used to take a call to override the existing
PPS-metadata, by either writing the entire new PPS metadata, or by
writing only the PPS override parameters.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 .../drm/i915/display/intel_display_types.h    |  16 ++
 drivers/gpu/drm/i915/display/intel_dp.c       | 178 ++++++++++++++++++
 2 files changed, 194 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 6c69922313d6..23282695a47f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1292,6 +1292,21 @@ struct intel_dp_pcon_frl {
 	int trained_rate_gbps;
 };
 
+struct intel_dp_pcon_dsc {
+	bool enc_support;
+	bool pps_override_support;
+	bool blk_prediction_support;
+	u8 version_major;
+	u8 version_minor;
+	u8 color_fmt_mask;
+	u8 color_depth_mask;
+	u8 max_slices;;
+	u8 max_slice_width;
+	u8 line_buf_bit_depth;
+	u8 bpp_precision_incr;
+	int rc_buf_size;
+};
+
 struct intel_dp {
 	i915_reg_t output_reg;
 	u32 DP;
@@ -1415,6 +1430,7 @@ struct intel_dp {
 	bool hobl_active;
 
 	struct intel_dp_pcon_frl frl;
+	struct intel_dp_pcon_dsc pcon_dsc;
 };
 
 enum lspcon_vendor {
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index e6c4cb844e37..b4f8abaea607 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3882,6 +3882,182 @@ cpt_set_link_train(struct intel_dp *intel_dp,
 	intel_de_posting_read(dev_priv, intel_dp->output_reg);
 }
 
+void intel_dp_get_pcon_dsc_cap(struct intel_dp *intel_dp)
+{
+	u8 buf;
+	u8 rc_buf_blk_size;
+	u8 max_slices = 0;
+
+	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
+	struct intel_dp_pcon_dsc *pcon_dsc = &intel_dp->pcon_dsc;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_ENCODER, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_ENCODER\n");
+		return;
+	}
+	pcon_dsc->enc_support = buf & DP_PCON_DSC_ENCODER_SUPPORTED;
+	pcon_dsc->pps_override_support = buf & DP_PCON_DSC_PPS_ENC_OVERRIDE;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_VERSION, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_VERSION\n");
+		return;
+	}
+	pcon_dsc->version_major = (buf & DP_PCON_DSC_MAJOR_MASK) >>
+				  DP_PCON_DSC_MAJOR_SHIFT;
+	pcon_dsc->version_minor = (buf & DP_PCON_DSC_MINOR_MASK) >>
+				  DP_PCON_DSC_MINOR_SHIFT;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_RC_BUF_BLK_INFO, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_RC_BUF_BLK_INFO\n");
+		return;
+	}
+
+	switch (buf & DP_PCON_DSC_RC_BUF_BLK_SIZE) {
+	case DP_PCON_DSC_RC_BUF_BLK_1KB :
+		rc_buf_blk_size = 1;
+		break;
+	case DP_PCON_DSC_RC_BUF_BLK_4KB :
+		rc_buf_blk_size = 4;
+		break;
+	case DP_PCON_DSC_RC_BUF_BLK_16KB :
+		rc_buf_blk_size = 16;
+		break;
+	case DP_PCON_DSC_RC_BUF_BLK_64KB :
+		rc_buf_blk_size = 64;
+		break;
+	default :
+		rc_buf_blk_size = 0;
+	}
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_RC_BUF_SIZE, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_RC_BUF_SIZE\n");
+		return;
+	}
+	/* storing rc_buf_size in bytes */
+	pcon_dsc->rc_buf_size = (buf + 1) * rc_buf_blk_size * 1024;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_SLICE_CAP_2, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_SLICE_CAP_2\n");
+		return;
+	}
+	if (buf & DP_PCON_DSC_24_PER_DSC_ENC)
+	       max_slices = 24;
+	else if (buf & DP_PCON_DSC_20_PER_DSC_ENC)
+		max_slices = 20;
+	else if (buf & DP_PCON_DSC_16_PER_DSC_ENC)
+		max_slices = 16;
+
+	if (max_slices == 0) {
+		if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_SLICE_CAP_1,
+				      &buf) < 0) {
+			drm_err(&i915->drm, "Failed to read DP_PCON_DSC_SLICE_CAP_2\n");
+			return;
+		}
+
+		if (buf & DP_PCON_DSC_12_PER_DSC_ENC)
+			max_slices = 12;
+		else if (buf & DP_PCON_DSC_10_PER_DSC_ENC)
+			max_slices = 10;
+		else if (buf & DP_PCON_DSC_8_PER_DSC_ENC)
+			max_slices = 8;
+		else if (buf & DP_PCON_DSC_6_PER_DSC_ENC)
+			max_slices = 6;
+		else if (buf & DP_PCON_DSC_4_PER_DSC_ENC)
+			max_slices = 4;
+		else if (buf & DP_PCON_DSC_2_PER_DSC_ENC)
+			max_slices = 2;
+		else if (buf & DP_PCON_DSC_1_PER_DSC_ENC)
+			max_slices = 1;
+	}
+
+	pcon_dsc->max_slices = max_slices;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_BUF_BIT_DEPTH, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_BUF_BIT_DEPTH\n");
+		return;
+	}
+	switch (buf & DP_PCON_DSC_BIT_DEPTH_MASK) {
+	case DP_PCON_DSC_DEPTH_8_BITS :
+		pcon_dsc->line_buf_bit_depth = 8;
+		break;
+	case DP_PCON_DSC_DEPTH_9_BITS :
+		pcon_dsc->line_buf_bit_depth = 9;
+		break;
+	case DP_PCON_DSC_DEPTH_10_BITS :
+		pcon_dsc->line_buf_bit_depth = 10;
+		break;
+	case DP_PCON_DSC_DEPTH_11_BITS :
+		pcon_dsc->line_buf_bit_depth = 11;
+		break;
+	case DP_PCON_DSC_DEPTH_12_BITS :
+		pcon_dsc->line_buf_bit_depth = 12;
+		break;
+	case DP_PCON_DSC_DEPTH_13_BITS :
+		pcon_dsc->line_buf_bit_depth = 13;
+		break;
+	case DP_PCON_DSC_DEPTH_14_BITS :
+		pcon_dsc->line_buf_bit_depth = 14;
+		break;
+	case DP_PCON_DSC_DEPTH_15_BITS :
+		pcon_dsc->line_buf_bit_depth = 15;
+		break;
+	case DP_PCON_DSC_DEPTH_16_BITS :
+		pcon_dsc->line_buf_bit_depth = 16;
+		break;
+	default :
+		pcon_dsc->line_buf_bit_depth = 0;
+	}
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_BLOCK_PREDICTION, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_BLOCK_PREDICTION\n");
+		return;
+	}
+	if (buf && DP_PCON_DSC_BLOCK_PRED_SUPPORT)
+		pcon_dsc->blk_prediction_support = true;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_ENC_COLOR_FMT_CAP, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_ENC_COLOR_FMT_CAP\n");
+		return;
+	}
+	pcon_dsc->color_fmt_mask = buf;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_ENC_COLOR_DEPTH_CAP, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_ENC_COLOR_DEPTH_CAP\n");
+		return;
+	}
+	pcon_dsc->color_depth_mask = buf;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_MAX_SLICE_WIDTH, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_MAX_SLICE_WIDTH\n");
+		return;
+	}
+	pcon_dsc->max_slice_width = buf;;
+
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_BPP_INCR, &buf) < 0) {
+		drm_err(&i915->drm, "Failed to read DP_PCON_DSC_BPP_INCR\n");
+		return;
+	}
+	switch(buf & DP_PCON_DSC_BPP_INCR_MASK) {
+	case DP_PCON_DSC_ONE_16TH_BPP:
+		pcon_dsc->bpp_precision_incr = 16;
+		break;
+	case DP_PCON_DSC_ONE_8TH_BPP:
+		pcon_dsc->bpp_precision_incr = 8;
+		break;
+	case DP_PCON_DSC_ONE_4TH_BPP:
+		pcon_dsc->bpp_precision_incr = 4;
+		break;
+	case DP_PCON_DSC_ONE_HALF_BPP:
+		pcon_dsc->bpp_precision_incr = 2;
+		break;
+	case DP_PCON_DSC_ONE_BPP:
+		pcon_dsc->bpp_precision_incr = 1;
+		break;
+	default :
+		pcon_dsc->bpp_precision_incr = 0;
+	}
+}
+
 static int intel_dp_get_max_rate_gbps(struct intel_dp *intel_dp)
 {
 	int max_link_clock, max_lanes, max_rate_khz, max_rate_gbps;
@@ -6659,6 +6835,8 @@ intel_dp_update_dfp(struct intel_dp *intel_dp,
 		    intel_dp->dfp.max_tmds_clock,
 		    intel_dp->dfp.pcon_max_frl,
 		    intel_dp->dfp.sink_max_frl);
+
+	intel_dp_get_pcon_dsc_cap(intel_dp);
 }
 
 static void
-- 
2.17.1



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