[Intel-gfx] [PATCH v5 2/7] drm/i915/dp: Add support of BT.2020 Colorimetry to DP MSA

[Gwan-gyeong Mun]

When BT.2020 Colorimetry output is used for DP, we should program BT.2020
Colorimetry to MSA and VSC SDP. It adds output_colorspace to
intel_crtc_state struct as a place holder of pipe's output colorspace.
In order to distinguish needed colorimetry for VSC SDP, it adds
intel_dp_needs_vsc_sdp function.
If the output colorspace requires vsc sdp or output format is YCbCr 4:2:0,
it uses MSA with VSC SDP.

As per DP 1.4a spec section 2.2.4.3 [MSA Field for Indication of
Color Encoding Format and Content Color Gamut] while sending
BT.2020 Colorimetry signals we should program MSA MISC1 fields which
indicate VSC SDP for the Pixel Encoding/Colorimetry Format.

v2: Remove useless parentheses
v3: Addressed review comments from Ville
    - In order to checking output format and output colorspace on
      intel_dp_needs_vsc_sdp(), it passes entire intel_crtc_state struct
      value.
    - Remove a pointless variable.

Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
Reviewed-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c      |  7 +++--
 .../drm/i915/display/intel_display_types.h    |  3 ++
 drivers/gpu/drm/i915/display/intel_dp.c       | 29 ++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_dp.h       |  1 +
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 49c35af583f9..87dc5a19cb7b 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1737,11 +1737,12 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
 	/*
 	 * As per DP 1.4a spec section 2.2.4.3 [MSA Field for Indication
 	 * of Color Encoding Format and Content Color Gamut] while sending
-	 * YCBCR 420 signals we should program MSA MISC1 fields which
-	 * indicate VSC SDP for the Pixel Encoding/Colorimetry Format.
+	 * YCBCR 420, HDR BT.2020 signals we should program MSA MISC1 fields
+	 * which indicate VSC SDP for the Pixel Encoding/Colorimetry Format.
 	 */
-	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+	if (intel_dp_needs_vsc_sdp(crtc_state))
 		temp |= TRANS_MSA_USE_VSC_SDP;
+
 	I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 61277a87dbe7..c62bad369c8e 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -971,6 +971,9 @@ struct intel_crtc_state {
 	/* Output format RGB/YCBCR etc */
 	enum intel_output_format output_format;
 
+	/* Output colorspace sRGB/BT.2020 etc */
+	u32 output_colorspace;
+
 	/* Output down scaling is done in LSPCON device */
 	bool lspcon_downsampling;
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 776be3e16ac6..6b7587c71e49 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2187,6 +2187,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 		pipe_config->has_pch_encoder = true;
 
 	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+	pipe_config->output_colorspace = intel_conn_state->base.colorspace;
+
 	if (lspcon->active)
 		lspcon_ycbcr420_config(&intel_connector->base, pipe_config);
 	else
@@ -4445,6 +4447,31 @@ u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
 	return 0;
 }
 
+bool
+intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state)
+{
+	/*
+	 * As per DP 1.4a spec section 2.2.4.3 [MSA Field for Indication
+	 * of Color Encoding Format and Content Color Gamut], in order to
+	 * sending YCBCR 420 or HDR BT.2020 signals we should use DP VSC SDP.
+	 */
+	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+		return true;
+
+	switch (crtc_state->output_colorspace) {
+	case DRM_MODE_COLORIMETRY_SYCC_601:
+	case DRM_MODE_COLORIMETRY_OPYCC_601:
+	case DRM_MODE_COLORIMETRY_BT2020_YCC:
+	case DRM_MODE_COLORIMETRY_BT2020_RGB:
+	case DRM_MODE_COLORIMETRY_BT2020_CYCC:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
 static void
 intel_dp_setup_vsc_sdp(struct intel_dp *intel_dp,
 		       const struct intel_crtc_state *crtc_state,
@@ -4573,7 +4600,7 @@ void intel_dp_vsc_enable(struct intel_dp *intel_dp,
 			 const struct intel_crtc_state *crtc_state,
 			 const struct drm_connector_state *conn_state)
 {
-	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_YCBCR420)
+	if (!intel_dp_needs_vsc_sdp(crtc_state))
 		return;
 
 	intel_dp_setup_vsc_sdp(intel_dp, crtc_state, conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index be13cb395ef8..87883d0d5977 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -112,6 +112,7 @@ bool intel_dp_read_dpcd(struct intel_dp *intel_dp);
 bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp);
 int intel_dp_link_required(int pixel_clock, int bpp);
 int intel_dp_max_data_rate(int max_link_clock, int max_lanes);
+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);
-- 
2.23.0