@@ -956,6 +956,45 @@ int drm_display_info_set_bus_formats(struct drm_display_info *info,
* is no longer protected and userspace should take appropriate action
* (whatever that might be).
*
+ * HDR_OUTPUT_METADATA:
+ * Connector property to enable userspace to send HDR Metadata to
+ * driver. This metadata is based on the composition and blending
+ * policies decided by user, taking into account the hardware and
+ * sink capabilities. The driver gets this metadata and creates a
+ * Dynamic Range and Mastering Infoframe (DRM) in case of HDMI,
+ * SDP packet (Non-audio INFOFRAME SDP v1.3) for DP. This is then
+ * sent to sink. This notifies the sink of the upcoming frame's Color
+ * Encoding and Luminance parameters.
+ *
+ * Userspace first need to detect the HDR capabilities of sink by
+ * reading and parsing the EDID. Details of HDR metadata for HDMI
+ * are added in CTA 861.G spec. For DP , its defined in VESA DP
+ * Standard v1.4. It needs to then get the metadata information
+ * of the video/game/app content which are encoded in HDR (basically
+ * using HDR transfer functions). With this information it needs to
+ * decide on a blending policy and compose the relevant
+ * layers/overlays into a common format. Once this blending is done,
+ * userspace will be aware of the metadata of the composed frame to
+ * be send to sink. It then uses this property to communicate this
+ * metadata to driver which then make a Infoframe packet and sends
+ * to sink based on the type of encoder connected.
+ *
+ * Userspace will be responsible to do Tone mapping operation in case:
+ * - Some layers are HDR and others are SDR
+ * - HDR layers luminance is not same as sink
+ * It will even need to do colorspace conversion and get all layers
+ * to one common colorspace for blending. It can use either GL, Media
+ * or display engine to get this done based on the capabilties of the
+ * associated hardware.
+ *
+ * Driver expects metadata to be put in &hdr_output_metadata structure
+ * from userspace. This is received as blob and stored in
+ * &drm_connector_state.hdr_output_metadata. It parses EDID and saves the
+ * sink metadata in &hdr_sink_metadata, as &drm_connector.hdr_sink_metadata.
+ * Driver uses &drm_hdmi_infoframe_set_hdr_metadata helper to set the HDR
+ * metadata, &hdmi_drm_infoframe_pack to pack the infoframe as per spec,
+ * in case of HDMI encoder.
+ *
* max bpc:
* This range property is used by userspace to limit the bit depth. When
* used the driver would limit the bpc in accordance with the valid range
@@ -1244,6 +1244,7 @@ struct drm_connector {
*/
struct llist_node free_node;
+ /** @hdr_sink_metadata: HDR Metadata Information read from sink */
struct hdr_sink_metadata hdr_sink_metadata;
};
@@ -837,8 +837,8 @@ struct drm_mode_config {
struct drm_property *writeback_out_fence_ptr_property;
/**
- * hdr_output_metadata_property: Connector property containing hdr
- * metatda. This will be provided by userspace compositors based
+ * @hdr_output_metadata_property: Connector property containing hdr
+ * metatada. This will be provided by userspace compositors based
* on HDR content
*/
struct drm_property *hdr_output_metadata_property;
@@ -367,8 +367,19 @@ struct hdr_static_metadata {
__u16 min_cll;
};
+/**
+ * struct hdr_sink_metadata - HDR sink metadata
+ *
+ * Metadata Information read from Sink's EDID
+ */
struct hdr_sink_metadata {
+ /**
+ * @metadata_type: Static_Metadata_Descriptor_ID.
+ */
__u32 metadata_type;
+ /**
+ * @hdmi_type1: HDR Metadata Infoframe.
+ */
union {
struct hdr_static_metadata hdmi_type1;
};
@@ -398,6 +409,7 @@ ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *fram
* @spd: spd infoframe
* @vendor: union of all vendor infoframes
* @audio: audio infoframe
+ * @drm: Dynamic Range and Mastering infoframe
*
* This is used by the generic pack function. This works since all infoframes
* have the same header which also indicates which type of infoframe should be
@@ -33,6 +33,15 @@
extern "C" {
#endif
+/**
+ * DOC: overview
+ *
+ * DRM exposes many UAPI and structure definition to have a consistent
+ * and standardized interface with user.
+ * Userspace can refer to these structure definitions and UAPI formats
+ * to communicate to driver
+ */
+
#define DRM_CONNECTOR_NAME_LEN 32
#define DRM_DISPLAY_MODE_LEN 32
#define DRM_PROP_NAME_LEN 32
@@ -630,24 +639,87 @@ struct drm_color_lut {
__u16 reserved;
};
-/* HDR Metadata Infoframe as per 861.G spec */
+/**
+ * struct hdr_metadata_infoframe - HDR Metadata Infoframe Data.
+ *
+ * HDR Metadata Infoframe as per CTA 861.G spec. This is expected
+ * to match exactly with the spec.
+ *
+ * Userspace is expected to pass the metadata information as per
+ * the format described in this structure.
+ */
struct hdr_metadata_infoframe {
+ /**
+ * @eotf: Electro-Optical Transfer Function (EOTF)
+ * used in the stream.
+ */
__u8 eotf;
+ /**
+ * @metadata_type: Static_Metadata_Descriptor_ID.
+ */
__u8 metadata_type;
+ /**
+ * @display_primaries: Color Primaries of the Data.
+ * These are coded as unsigned 16-bit values in units of
+ * 0.00002, where 0x0000 represents zero and 0xC350
+ * represents 1.0000.
+ * @display_primaries.x: X cordinate of color primary.
+ * @display_primaries.y: Y cordinate of color primary.
+ */
struct {
__u16 x, y;
} display_primaries[3];
+ /**
+ * @white_point: White Point of Colorspace Data.
+ * These are coded as unsigned 16-bit values in units of
+ * 0.00002, where 0x0000 represents zero and 0xC350
+ * represents 1.0000.
+ * @white_point.x: X cordinate of whitepoint of color primary.
+ * @white_point.y: Y cordinate of whitepoint of color primary.
+ */
struct {
__u16 x, y;
} white_point;
+ /**
+ * @max_display_mastering_luminance: Max Mastering Display Luminance.
+ * This value is coded as an unsigned 16-bit value in units of 1 cd/m2,
+ * where 0x0001 represents 1 cd/m2 and 0xFFFF represents 65535 cd/m2.
+ */
__u16 max_display_mastering_luminance;
+ /**
+ * @min_display_mastering_luminance: Min Mastering Display Luminance.
+ * This value is coded as an unsigned 16-bit value in units of
+ * 0.0001 cd/m2, where 0x0001 represents 0.0001 cd/m2 and 0xFFFF
+ * represents 6.5535 cd/m2.
+ */
__u16 min_display_mastering_luminance;
+ /**
+ * @max_cll: Max Content Light Level.
+ * This value is coded as an unsigned 16-bit value in units of 1 cd/m2,
+ * where 0x0001 represents 1 cd/m2 and 0xFFFF represents 65535 cd/m2.
+ */
__u16 max_cll;
+ /**
+ * @max_fall: Max Frame Average Light Level.
+ * This value is coded as an unsigned 16-bit value in units of 1 cd/m2,
+ * where 0x0001 represents 1 cd/m2 and 0xFFFF represents 65535 cd/m2.
+ */
__u16 max_fall;
};
+/**
+ * struct hdr_output_metadata - HDR output metadata
+ *
+ * Metadata Information to be passed from userspace
+ */
struct hdr_output_metadata {
+ /**
+ * @metadata_type: Static_Metadata_Descriptor_ID.
+ */
__u32 metadata_type;
+ /**
+ * @hdmi_metadata_type1: HDR Metadata Infoframe.
+ */
union {
struct hdr_metadata_infoframe hdmi_metadata_type1;
};