[v8 1/2] drm: Add colorspace connector property

Uma Shankar uma.shankar at intel.com
Tue Jan 29 15:52:55 UTC 2019


Create a new connector property to program colorspace to sink devices.
Modern sink devices support more than 1 type of colorspace like 601,
709, BT2020 etc. This helps to switch based on content type which is
to be displayed. The decision lies with compositors as to in which
scenarios, a particular colorspace will be picked.

This will be helpful mostly to switch to higher gamut colorspaces
like BT2020 when the media content is encoded as BT2020. Thereby
giving a good visual experience to users.

The expectation from userspace is that it should parse the EDID
and get supported colorspaces. Use this property and switch to the
one supported. Driver will expose the platform supported colorspaces,
however sink supported colorspaces should be retrieved by userspace
from EDID.

Basically the expectation from userspace is:
 - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink
   colorspace
 - Set this new property to let the sink know what it
   converted the CRTC output to.

v2: Addressed Maarten and Ville's review comments. Enhanced
the colorspace enum to incorporate both HDMI and DP supported
colorspaces. Also, added a default option for colorspace.

v3: Removed Adobe references from enum definitions as per
Ville, Hans Verkuil and Jonas Karlman suggestions. Changed
Default to an unset state where driver will assign the colorspace
is not chosen by user, suggested by Ville and Maarten. Addressed
other misc review comments from Maarten. Split the changes to
have separate colorspace property for DP and HDMI.

v4: Addressed Chris and Ville's review comments, and created a
common colorspace property for DP and HDMI, filtered the list
based on the colorspaces supported by the respective protocol
standard.

v5: Made the property creation helper accept enum list based on
platform capabilties as suggested by Shashank. Consolidated HDMI
and DP property creation in the common helper.

v6: Addressed Shashank's review comments.

v7: Added defines instead of enum in uapi as per Brian Starkey's
suggestion in order to go with string matching at userspace. Updated
the commit message to add more details as well kernel docs.

v8: Addressed Maarten's review comments.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/drm_atomic_uapi.c |  4 ++
 drivers/gpu/drm/drm_connector.c   | 95 +++++++++++++++++++++++++++++++++++++++
 include/drm/drm_connector.h       | 17 +++++++
 include/uapi/drm/drm_mode.h       | 32 +++++++++++++
 4 files changed, 148 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 9a1f41a..9b5d44f 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -746,6 +746,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
 			return -EINVAL;
 		}
 		state->content_protection = val;
+	} else if (property == connector->colorspace_property) {
+		state->colorspace = val;
 	} else if (property == config->writeback_fb_id_property) {
 		struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, NULL, val);
 		int ret = drm_atomic_set_writeback_fb_for_connector(state, fb);
@@ -814,6 +816,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
 		*val = state->picture_aspect_ratio;
 	} else if (property == config->content_type_property) {
 		*val = state->content_type;
+	} else if (property == connector->colorspace_property) {
+		*val = state->colorspace;
 	} else if (property == connector->scaling_mode_property) {
 		*val = state->scaling_mode;
 	} else if (property == connector->content_protection_property) {
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 8475396..e8575d1 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -826,6 +826,54 @@ int drm_display_info_set_bus_formats(struct drm_display_info *info,
 };
 DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
 
+/* List of HDMI Colorspaces supported */
+static const struct drm_prop_enum_list hdmi_colorspaces[] = {
+	/* For Default case, driver will set the colorspace */
+	{ DRM_MODE_COLORIMETRY_DEFAULT, "Default" },
+	/* Standard Definition Colorimetry based on CEA 861 */
+	{ DRM_MODE_COLORIMETRY_ITU_601, "ITU_601" },
+	{ DRM_MODE_COLORIMETRY_ITU_709, "ITU_709" },
+	/* Standard Definition Colorimetry based on IEC 61966-2-4 */
+	{ DRM_MODE_COLORIMETRY_XV_YCC_601, "XV_YCC_601" },
+	/* High Definition Colorimetry based on IEC 61966-2-4 */
+	{ DRM_MODE_COLORIMETRY_XV_YCC_709, "XV_YCC_709" },
+	/* Colorimetry based on IEC 61966-2-1/Amendment 1 */
+	{ DRM_MODE_COLORIMETRY_S_YCC_601, "S_YCC_601" },
+	/* Colorimetry based on IEC 61966-2-5 [33] */
+	{ DRM_MODE_COLORIMETRY_OPYCC_601, "opYCC_601" },
+	/* Colorimetry based on IEC 61966-2-5 */
+	{ DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
+	/* Colorimetry based on ITU-R BT.2020 */
+	{ DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
+	/* Colorimetry based on ITU-R BT.2020 */
+	{ DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
+	/* Colorimetry based on ITU-R BT.2020 */
+	{ DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
+};
+
+/* List of DP Colorspaces supported */
+static const struct drm_prop_enum_list dp_colorspaces[] = {
+	/* For Default case, driver will set the colorspace */
+	{ DRM_MODE_COLORIMETRY_DEFAULT, "Default" },
+	/* Standard Definition Colorimetry based on CEA 861 */
+	{ DRM_MODE_COLORIMETRY_ITU_601, "ITU_601" },
+	{ DRM_MODE_COLORIMETRY_ITU_709, "ITU_709" },
+	/* Standard Definition Colorimetry based on IEC 61966-2-4 */
+	{ DRM_MODE_COLORIMETRY_XV_YCC_601, "XV_YCC_601" },
+	/* High Definition Colorimetry based on IEC 61966-2-4 */
+	{ DRM_MODE_COLORIMETRY_XV_YCC_709, "XV_YCC_709" },
+	/* Colorimetry based on IEC 61966-2-5 */
+	{ DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
+	/* DP MSA Colorimetry */
+	{ DRM_MODE_DP_COLORIMETRY_Y_CBCR_ITU_601, "YCBCR_ITU_601" },
+	{ DRM_MODE_DP_COLORIMETRY_Y_CBCR_ITU_709, "YCBCR_ITU_709" },
+	{ DRM_MODE_DP_COLORIMETRY_SRGB, "sRGB" },
+	{ DRM_MODE_DP_COLORIMETRY_RGB_WIDE_GAMUT, "RGB Wide Gamut" },
+	{ DRM_MODE_DP_COLORIMETRY_SCRGB, "scRGB" },
+	{ DRM_MODE_DP_COLORIMETRY_DCI_P3, "DCI-P3" },
+	{ DRM_MODE_DP_COLORIMETRY_CUSTOM_COLOR_PROFILE, "Custom Profile" },
+};
+
 /**
  * DOC: standard connector properties
  *
@@ -1548,6 +1596,53 @@ int drm_mode_create_aspect_ratio_property(struct drm_device *dev)
 EXPORT_SYMBOL(drm_mode_create_aspect_ratio_property);
 
 /**
+ * DOC: standard connector properties
+ *
+ * Colorspace:
+ *     drm_mode_create_colorspace_property - create colorspace property
+ *     This property helps select a suitable colorspace based on the sink
+ *     capability. Modern sink devices support wider gamut like BT2020.
+ *     This helps switch to BT2020 mode if the BT2020 encoded video stream
+ *     is being played by the user, same for any other colorspace. Thereby
+ *     giving a good visual experience to users.
+ *
+ *     The expectation from userspace is that it should parse the EDID
+ *     and get supported colorspaces. Use this property and switch to the
+ *     one supported. Driver will expose the platform supported colorspaces,
+ *     however sink supported colorspaces should be retrieved by userspace
+ *     from EDID.
+ *
+ *     Basically the expectation from userspace is:
+ *      - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink
+ *        colorspace
+ *      - Set this new property to let the sink know what it
+ *        converted the CRTC output to.
+ *      - This property is just to inform sink what colorspace
+ *        source is trying to drive.
+ *
+ *     Called by a driver the first time it's needed, must be attached to
+ *     desired connectors.
+ */
+int drm_mode_create_colorspace_property(struct drm_connector *connector,
+					const struct drm_prop_enum_list *props,
+					int num_values)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop;
+
+	prop = drm_property_create_enum(dev, DRM_MODE_PROP_ENUM,
+					"Colorspace",
+					props, num_values);
+	if (!prop)
+		return -ENOMEM;
+
+	connector->colorspace_property = prop;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_mode_create_colorspace_property);
+
+/**
  * drm_mode_create_content_type_property - create content type property
  * @dev: DRM device
  *
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 9941613..e32cd11 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -31,6 +31,7 @@
 #include <drm/drm_util.h>
 
 #include <uapi/drm/drm_mode.h>
+#include <drm/drm_property.h>
 
 struct drm_connector_helper_funcs;
 struct drm_modeset_acquire_ctx;
@@ -503,6 +504,13 @@ struct drm_connector_state {
 	unsigned int content_protection;
 
 	/**
+	 * @colorspace: State variable for Connector property to request
+	 * colorspace change on Sink. This is most commonly used to switch
+	 * to wider color gamuts like BT2020.
+	 */
+	u32 colorspace;
+
+	/**
 	 * @writeback_job: Writeback job for writeback connectors
 	 *
 	 * Holds the framebuffer and out-fence for a writeback connector. As
@@ -995,6 +1003,12 @@ struct drm_connector {
 	struct drm_property *content_protection_property;
 
 	/**
+	 * @colorspace_property: Connector property to set the suitable
+	 * colorspace supported by the sink.
+	 */
+	struct drm_property *colorspace_property;
+
+	/**
 	 * @path_blob_ptr:
 	 *
 	 * DRM blob property data for the DP MST path property. This should only
@@ -1269,6 +1283,9 @@ int drm_connector_attach_vrr_capable_property(
 int drm_connector_attach_content_protection_property(
 		struct drm_connector *connector);
 int drm_mode_create_aspect_ratio_property(struct drm_device *dev);
+int drm_mode_create_colorspace_property(struct drm_connector *connector,
+					const struct drm_prop_enum_list *props,
+					int num_values);
 int drm_mode_create_content_type_property(struct drm_device *dev);
 void drm_hdmi_avi_infoframe_content_type(struct hdmi_avi_infoframe *frame,
 					 const struct drm_connector_state *conn_state);
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index a439c2e..14bfda3 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -210,6 +210,38 @@
 #define DRM_MODE_CONTENT_PROTECTION_DESIRED     1
 #define DRM_MODE_CONTENT_PROTECTION_ENABLED     2
 
+/*
+ * This is a consolidated colorimetry list supported by HDMI and
+ * DP protocol standard. The respective connectors will register
+ * a property with the subset of this list (supported by that
+ * respective protocol). Userspace will set the colorspace through
+ * a colorspace property which will be created and exposed to
+ * userspace.
+ */
+
+/* For Default case, driver will set the colorspace */
+#define DRM_MODE_COLORIMETRY_DEFAULT			0
+/* CEA 861 Normal Colorimetry options */
+#define DRM_MODE_COLORIMETRY_ITU_601			1
+#define DRM_MODE_COLORIMETRY_ITU_709			2
+/* CEA 861 Extended Colorimetry Options */
+#define DRM_MODE_COLORIMETRY_XV_YCC_601			3
+#define DRM_MODE_COLORIMETRY_XV_YCC_709			4
+#define DRM_MODE_COLORIMETRY_S_YCC_601			5
+#define DRM_MODE_COLORIMETRY_OPYCC_601			6
+#define DRM_MODE_COLORIMETRY_OPRGB			7
+#define DRM_MODE_COLORIMETRY_BT2020_RGB			8
+#define DRM_MODE_COLORIMETRY_BT2020_YCC			9
+#define DRM_MODE_COLORIMETRY_BT2020_CYCC		10
+/* DP MSA Colorimetry Options */
+#define DRM_MODE_DP_COLORIMETRY_Y_CBCR_ITU_601		11
+#define DRM_MODE_DP_COLORIMETRY_Y_CBCR_ITU_709		12
+#define DRM_MODE_DP_COLORIMETRY_SRGB			13
+#define DRM_MODE_DP_COLORIMETRY_RGB_WIDE_GAMUT		14
+#define DRM_MODE_DP_COLORIMETRY_SCRGB			15
+#define DRM_MODE_DP_COLORIMETRY_DCI_P3			16
+#define DRM_MODE_DP_COLORIMETRY_CUSTOM_COLOR_PROFILE	17
+
 struct drm_mode_modeinfo {
 	__u32 clock;
 	__u16 hdisplay;
-- 
1.9.1



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