[PATCH] drm/amd/display: Expose active display color configurations to userspace

[Werner Sembach]

xrandr --prop and other userspace info tools have currently no way of
telling which color configuration is used on HDMI and DP ports.

The ongoing transsition from HDMI 1.4 to 2.0 and the different bandwidth
requirements of YCbCr 4:2:0 and RGB color format raise different
incompatibilities. Having these configuration information readily
available is a useful tool in debuging washed out colors, color artefacts
on small fonts and missing refreshrate options.

Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c   | 58 +++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h      |  4 ++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 36 ++++++++++++
 3 files changed, 98 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index f753e04fee99..c0404bcda31b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -986,6 +986,40 @@ static const struct drm_prop_enum_list amdgpu_dither_enum_list[] =
 	{ AMDGPU_FMT_DITHER_ENABLE, "on" },
 };
 
+static const struct drm_prop_enum_list amdgpu_active_pixel_encoding_enum_list[] = {
+	{ PIXEL_ENCODING_UNDEFINED, "undefined" },
+	{ PIXEL_ENCODING_RGB, "RGB" },
+	{ PIXEL_ENCODING_YCBCR422, "YCbCr 4:2:2" },
+	{ PIXEL_ENCODING_YCBCR444, "YCbCr 4:4:4" },
+	{ PIXEL_ENCODING_YCBCR420, "YCbCr 4:2:0" },
+};
+
+static const struct drm_prop_enum_list amdgpu_active_display_color_depth_enum_list[] = {
+	{ COLOR_DEPTH_UNDEFINED, "undefined" },
+	{ COLOR_DEPTH_666, "6 bit" },
+	{ COLOR_DEPTH_888, "8 bit" },
+	{ COLOR_DEPTH_101010, "10 bit" },
+	{ COLOR_DEPTH_121212, "12 bit" },
+	{ COLOR_DEPTH_141414, "14 bit" },
+	{ COLOR_DEPTH_161616, "16 bit" },
+	{ COLOR_DEPTH_999, "9 bit" },
+	{ COLOR_DEPTH_111111, "11 bit" },
+};
+
+static const struct drm_prop_enum_list amdgpu_active_output_color_space_enum_list[] = {
+	{ COLOR_SPACE_UNKNOWN, "unknown" },
+	{ COLOR_SPACE_SRGB, "sRGB" },
+	{ COLOR_SPACE_SRGB_LIMITED, "sRGB limited" },
+	{ COLOR_SPACE_YCBCR601, "YCbCr 601" },
+	{ COLOR_SPACE_YCBCR709, "YCbCr 709" },
+	{ COLOR_SPACE_YCBCR601_LIMITED, "YCbCr 601 limited" },
+	{ COLOR_SPACE_YCBCR709_LIMITED, "YCbCr 709 limited" },
+	{ COLOR_SPACE_2020_RGB_FULLRANGE, "RGB 2020" },
+	{ COLOR_SPACE_2020_RGB_LIMITEDRANGE, "RGB 2020 limited" },
+	{ COLOR_SPACE_2020_YCBCR, "YCbCr 2020" },
+	{ COLOR_SPACE_ADOBERGB, "Adobe RGB" },
+};
+
 int amdgpu_display_modeset_create_props(struct amdgpu_device *adev)
 {
 	int sz;
@@ -1038,6 +1072,30 @@ int amdgpu_display_modeset_create_props(struct amdgpu_device *adev)
 						  "abm level", 0, 4);
 		if (!adev->mode_info.abm_level_property)
 			return -ENOMEM;
+
+		sz = ARRAY_SIZE(amdgpu_active_pixel_encoding_enum_list);
+		adev->mode_info.active_pixel_encoding_property =
+			drm_property_create_enum(adev_to_drm(adev), 0,
+				"active pixel encoding",
+				amdgpu_active_pixel_encoding_enum_list, sz);
+		if (!adev->mode_info.active_pixel_encoding_property)
+			return -ENOMEM;
+
+		sz = ARRAY_SIZE(amdgpu_active_display_color_depth_enum_list);
+		adev->mode_info.active_display_color_depth_property =
+			drm_property_create_enum(adev_to_drm(adev), 0,
+				"active display color depth",
+				amdgpu_active_display_color_depth_enum_list, sz);
+		if (!adev->mode_info.active_display_color_depth_property)
+			return -ENOMEM;
+
+		sz = ARRAY_SIZE(amdgpu_active_output_color_space_enum_list);
+		adev->mode_info.active_output_color_space_property =
+			drm_property_create_enum(adev_to_drm(adev), 0,
+				"active output color space",
+				amdgpu_active_output_color_space_enum_list, sz);
+		if (!adev->mode_info.active_output_color_space_property)
+			return -ENOMEM;
 	}
 
 	return 0;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
index 319cb19e1b99..ad43af6a878d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
@@ -337,6 +337,10 @@ struct amdgpu_mode_info {
 	struct drm_property *dither_property;
 	/* Adaptive Backlight Modulation (power feature) */
 	struct drm_property *abm_level_property;
+	/* Color settings */
+	struct drm_property *active_pixel_encoding_property;
+	struct drm_property *active_display_color_depth_property;
+	struct drm_property *active_output_color_space_property;
 	/* hardcoded DFP edid from BIOS */
 	struct edid *bios_hardcoded_edid;
 	int bios_hardcoded_edid_size;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index d699a5cf6c11..89465f74ca59 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5592,8 +5592,13 @@ int amdgpu_dm_connector_atomic_get_property(struct drm_connector *connector,
 	struct amdgpu_device *adev = drm_to_adev(dev);
 	struct dm_connector_state *dm_state =
 		to_dm_connector_state(state);
+	struct dm_crtc_state *dm_crtc_state = NULL;
 	int ret = -EINVAL;
 
+	if (state->crtc != NULL && state->crtc->state != NULL) {
+		dm_crtc_state = to_dm_crtc_state(state->crtc->state);
+	}
+
 	if (property == dev->mode_config.scaling_mode_property) {
 		switch (dm_state->scaling) {
 		case RMX_CENTER:
@@ -5623,6 +5628,21 @@ int amdgpu_dm_connector_atomic_get_property(struct drm_connector *connector,
 	} else if (property == adev->mode_info.abm_level_property) {
 		*val = dm_state->abm_level;
 		ret = 0;
+	} else if (property == adev->mode_info.active_pixel_encoding_property) {
+		*val = PIXEL_ENCODING_UNDEFINED;
+		if (dm_crtc_state != NULL && dm_crtc_state->stream != NULL)
+			*val = dm_crtc_state->stream->timing.pixel_encoding;
+		ret = 0;
+	} else if (property == adev->mode_info.active_display_color_depth_property) {
+		*val = COLOR_DEPTH_UNDEFINED;
+		if (dm_crtc_state != NULL && dm_crtc_state->stream != NULL)
+			*val = dm_crtc_state->stream->timing.display_color_depth;
+		ret = 0;
+	} else if (property == adev->mode_info.active_output_color_space_property) {
+		*val = COLOR_SPACE_UNKNOWN;
+		if (dm_crtc_state != NULL && dm_crtc_state->stream != NULL)
+			*val = dm_crtc_state->stream->output_color_space;
+		ret = 0;
 	}
 
 	return ret;
@@ -7083,6 +7103,22 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 			drm_connector_attach_content_protection_property(&aconnector->base, true);
 #endif
 	}
+
+	if (adev->mode_info.active_pixel_encoding_property) {
+		drm_object_attach_property(&aconnector->base.base,
+			adev->mode_info.active_pixel_encoding_property, 0);
+		DRM_DEBUG_DRIVER("amdgpu: attached active pixel encoding drm property");
+	}
+	if (adev->mode_info.active_display_color_depth_property) {
+		drm_object_attach_property(&aconnector->base.base,
+			adev->mode_info.active_display_color_depth_property, 0);
+		DRM_DEBUG_DRIVER("amdgpu: attached active color depth drm property");
+	}
+	if (adev->mode_info.active_output_color_space_property) {
+		drm_object_attach_property(&aconnector->base.base,
+			adev->mode_info.active_output_color_space_property, 0);
+		DRM_DEBUG_DRIVER("amdgpu: attached active output color space drm property");
+	}
 }
 
 static int amdgpu_dm_i2c_xfer(struct i2c_adapter *i2c_adap,
-- 
2.25.1