[PATCH v2 18/20] drm/msm/dp: Signal BT.2020 RGB on DP and eDP

[Xilin Wu]

Expose the standard DP Colorspace property with BT2020_RGB support and
carry the selected colorspace in bridge atomic state. Force a modeset
when it changes so the stream receives the corresponding VSC packet.

Signal full-range RGB to match the existing pixel path and retain CTA
range for YUV420. Reject BT2020_RGB with a YUV420-only mode. Reuse the
preceding VSC state, update and PSR handling for the new colorimetry.

Assisted-by: LLM
Signed-off-by: Xilin Wu <sophon at radxa.com>
---
 drivers/gpu/drm/msm/dp/dp_ctrl.c    |  2 +-
 drivers/gpu/drm/msm/dp/dp_display.c |  6 ++++--
 drivers/gpu/drm/msm/dp/dp_drm.c     |  9 ++++++++-
 drivers/gpu/drm/msm/dp/dp_drm.h     |  1 +
 drivers/gpu/drm/msm/dp/dp_utils.c   | 12 ++++++++++++
 drivers/gpu/drm/msm/dp/dp_utils.h   |  3 +++
 6 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 2fd8dd456852..a1a649c636c7 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -2669,7 +2669,7 @@ int msm_dp_ctrl_on_stream(struct msm_dp_ctrl *msm_dp_ctrl, struct msm_dp_panel *
 		/* Compliance tests may override the checked stream depth. */
 		if (panel->video_test) {
 			ret = msm_dp_utils_pack_vsc_sdp(&test_vsc_sdp,
-							DRM_MODE_COLORIMETRY_DEFAULT,
+							state->colorspace,
 							panel->msm_dp_mode.bpp / 3,
 							panel->msm_dp_mode.out_fmt_is_yuv_420);
 			if (ret)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 5a9162712540..34e1c48cdd79 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -728,14 +728,16 @@ int msm_dp_display_atomic_check(struct msm_dp *msm_dp_display,
 		return bpp;
 
 	state->bpp = bpp;
-	state->vsc_enabled = drm_mode_is_420_only(info, mode);
+	state->colorspace = conn_state->colorspace;
+	state->vsc_enabled = drm_mode_is_420_only(info, mode) ||
+			     state->colorspace != DRM_MODE_COLORIMETRY_DEFAULT;
 	if (!state->vsc_enabled)
 		return 0;
 
 	if (dp->panel->link_caps_valid && !dp->panel->vsc_sdp_supported)
 		return -EINVAL;
 
-	return msm_dp_utils_pack_vsc_sdp(&state->vsc_sdp, DRM_MODE_COLORIMETRY_DEFAULT,
+	return msm_dp_utils_pack_vsc_sdp(&state->vsc_sdp, state->colorspace,
 					bpp / 3, drm_mode_is_420_only(info, mode));
 }
 
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index 808b6fe3d650..0d17536f02fd 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -171,7 +171,7 @@ static int msm_dp_bridge_atomic_check(struct drm_bridge *bridge,
 
 	old_conn_state = drm_atomic_get_old_connector_state(conn_state->state,
 							    conn_state->connector);
-	if (old_conn_state->max_requested_bpc != conn_state->max_requested_bpc)
+	if (msm_dp_utils_needs_modeset(old_conn_state, conn_state))
 		crtc_state->mode_changed = true;
 
 	return 0;
@@ -456,11 +456,18 @@ struct drm_connector *msm_dp_drm_connector_init(struct msm_dp *msm_dp_display,
 					    struct drm_encoder *encoder)
 {
 	struct drm_connector *connector = NULL;
+	int ret;
 
 	connector = drm_bridge_connector_init(msm_dp_display->drm_dev, encoder);
 	if (IS_ERR(connector))
 		return connector;
 
+	ret = drm_mode_create_dp_colorspace_property(connector,
+						     BIT(DRM_MODE_COLORIMETRY_BT2020_RGB));
+	if (ret)
+		return ERR_PTR(ret);
+	drm_connector_attach_colorspace_property(connector);
+
 	if (!msm_dp_display->is_edp)
 		drm_connector_attach_dp_subconnector_property(connector);
 
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.h b/drivers/gpu/drm/msm/dp/dp_drm.h
index 122150d95bbb..0e85a1a55c88 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.h
+++ b/drivers/gpu/drm/msm/dp/dp_drm.h
@@ -20,6 +20,7 @@ struct msm_dp_bridge {
 struct msm_dp_bridge_state {
 	struct drm_bridge_state base;
 	u32 bpp;
+	enum drm_colorspace colorspace;
 	bool vsc_enabled;
 	struct dp_sdp vsc_sdp;
 };
diff --git a/drivers/gpu/drm/msm/dp/dp_utils.c b/drivers/gpu/drm/msm/dp/dp_utils.c
index bde627a6701b..431c18aa2096 100644
--- a/drivers/gpu/drm/msm/dp/dp_utils.c
+++ b/drivers/gpu/drm/msm/dp/dp_utils.c
@@ -140,6 +140,11 @@ int msm_dp_utils_pack_vsc_sdp(struct dp_sdp *sdp, enum drm_colorspace colorspace
 	case DRM_MODE_COLORIMETRY_DEFAULT:
 		vsc.colorimetry = DP_COLORIMETRY_DEFAULT;
 		break;
+	case DRM_MODE_COLORIMETRY_BT2020_RGB:
+		if (yuv420)
+			return -EINVAL;
+		vsc.colorimetry = DP_COLORIMETRY_BT2020_RGB;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -148,6 +153,13 @@ int msm_dp_utils_pack_vsc_sdp(struct dp_sdp *sdp, enum drm_colorspace colorspace
 	return ret < 0 ? ret : 0;
 }
 
+bool msm_dp_utils_needs_modeset(struct drm_connector_state *old_state,
+				struct drm_connector_state *new_state)
+{
+	return old_state->max_requested_bpc != new_state->max_requested_bpc ||
+	       old_state->colorspace != new_state->colorspace;
+}
+
 bool msm_dp_utils_psr_needs_modeset(const struct drm_crtc_state *state)
 {
 	/* active_changed alone also describes a normal self-refresh exit. */
diff --git a/drivers/gpu/drm/msm/dp/dp_utils.h b/drivers/gpu/drm/msm/dp/dp_utils.h
index e916de2a5929..81773db75c60 100644
--- a/drivers/gpu/drm/msm/dp/dp_utils.h
+++ b/drivers/gpu/drm/msm/dp/dp_utils.h
@@ -46,6 +46,9 @@ int msm_dp_utils_select_bpp(unsigned int bpc, unsigned int max_bpc,
 int msm_dp_utils_pack_vsc_sdp(struct dp_sdp *sdp, enum drm_colorspace colorspace,
 			      unsigned int bpc, bool yuv420);
 
+bool msm_dp_utils_needs_modeset(struct drm_connector_state *old_state,
+				struct drm_connector_state *new_state);
+
 bool msm_dp_utils_psr_needs_modeset(const struct drm_crtc_state *state);
 
 #endif /* _DP_UTILS_H_ */

-- 
2.56.0