diff options
Diffstat (limited to 'drivers/gpu/drm/drm_connector.c')
| -rw-r--r-- | drivers/gpu/drm/drm_connector.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index c9ac8b9e83ea..e17586aaa80f 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -956,6 +956,46 @@ static const struct drm_prop_enum_list hdmi_colorspaces[] = { * 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 &struct 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 &struct 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 |