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Diffstat (limited to 'Documentation/gpu/drm-kms.rst')
| -rw-r--r-- | Documentation/gpu/drm-kms.rst | 46 |
1 files changed, 6 insertions, 40 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index 7f788ca..47c2835 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -128,6 +128,12 @@ Connector Functions Reference Encoder Abstraction =================== +.. kernel-doc:: drivers/gpu/drm/drm_encoder.c + :doc: overview + +Encoder Functions Reference +--------------------------- + .. kernel-doc:: include/drm/drm_encoder.h :internal: @@ -207,46 +213,6 @@ future); drivers that do not wish to provide special handling for primary planes may make use of the helper functions described in ? to create and register a primary plane with standard capabilities. -Encoders (:c:type:`struct drm_encoder <drm_encoder>`) ------------------------------------------------------ - -An encoder takes pixel data from a CRTC and converts it to a format -suitable for any attached connectors. On some devices, it may be -possible to have a CRTC send data to more than one encoder. In that -case, both encoders would receive data from the same scanout buffer, -resulting in a "cloned" display configuration across the connectors -attached to each encoder. - -Encoder Initialization -~~~~~~~~~~~~~~~~~~~~~~ - -As for CRTCs, a KMS driver must create, initialize and register at least -one :c:type:`struct drm_encoder <drm_encoder>` instance. The -instance is allocated and zeroed by the driver, possibly as part of a -larger structure. - -Drivers must initialize the :c:type:`struct drm_encoder -<drm_encoder>` possible_crtcs and possible_clones fields before -registering the encoder. Both fields are bitmasks of respectively the -CRTCs that the encoder can be connected to, and sibling encoders -candidate for cloning. - -After being initialized, the encoder must be registered with a call to -:c:func:`drm_encoder_init()`. The function takes a pointer to the -encoder functions and an encoder type. Supported types are - -- DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A -- DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort -- DRM_MODE_ENCODER_LVDS for display panels -- DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video, - Component, SCART) -- DRM_MODE_ENCODER_VIRTUAL for virtual machine displays - -Encoders must be attached to a CRTC to be used. DRM drivers leave -encoders unattached at initialization time. Applications (or the fbdev -compatibility layer when implemented) are responsible for attaching the -encoders they want to use to a CRTC. - Cleanup ------- |