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Diffstat (limited to 'Documentation/gpu/drm-kms.rst')
-rw-r--r-- | Documentation/gpu/drm-kms.rst | 159 |
1 files changed, 35 insertions, 124 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index fa948b4e029b..f9a991bb87d4 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -15,6 +15,15 @@ be setup by initializing the following fields. - struct drm_mode_config_funcs \*funcs; Mode setting functions. +Modeset Base Object Abstraction +=============================== + +.. kernel-doc:: include/drm/drm_mode_object.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_mode_object.c + :export: + KMS Data Structures =================== @@ -125,6 +134,21 @@ Connector Functions Reference .. kernel-doc:: drivers/gpu/drm/drm_connector.c :export: +Encoder Abstraction +=================== + +.. kernel-doc:: drivers/gpu/drm/drm_encoder.c + :doc: overview + +Encoder Functions Reference +--------------------------- + +.. kernel-doc:: include/drm/drm_encoder.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_encoder.c + :export: + KMS Initialization and Cleanup ============================== @@ -198,46 +222,6 @@ 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 ------- @@ -320,90 +304,17 @@ KMS Locking KMS Properties ============== -Drivers may need to expose additional parameters to applications than -those described in the previous sections. KMS supports attaching -properties to CRTCs, connectors and planes and offers a userspace API to -list, get and set the property values. - -Properties are identified by a name that uniquely defines the property -purpose, and store an associated value. For all property types except -blob properties the value is a 64-bit unsigned integer. - -KMS differentiates between properties and property instances. Drivers -first create properties and then create and associate individual -instances of those properties to objects. A property can be instantiated -multiple times and associated with different objects. Values are stored -in property instances, and all other property information are stored in -the property and shared between all instances of the property. - -Every property is created with a type that influences how the KMS core -handles the property. Supported property types are - -DRM_MODE_PROP_RANGE - Range properties report their minimum and maximum admissible values. - The KMS core verifies that values set by application fit in that - range. - -DRM_MODE_PROP_ENUM - Enumerated properties take a numerical value that ranges from 0 to - the number of enumerated values defined by the property minus one, - and associate a free-formed string name to each value. Applications - can retrieve the list of defined value-name pairs and use the - numerical value to get and set property instance values. - -DRM_MODE_PROP_BITMASK - Bitmask properties are enumeration properties that additionally - restrict all enumerated values to the 0..63 range. Bitmask property - instance values combine one or more of the enumerated bits defined - by the property. - -DRM_MODE_PROP_BLOB - Blob properties store a binary blob without any format restriction. - The binary blobs are created as KMS standalone objects, and blob - property instance values store the ID of their associated blob - object. - - Blob properties are only used for the connector EDID property and - cannot be created by drivers. - -To create a property drivers call one of the following functions -depending on the property type. All property creation functions take -property flags and name, as well as type-specific arguments. - -- struct drm_property \*drm_property_create_range(struct - drm_device \*dev, int flags, const char \*name, uint64_t min, - uint64_t max); - Create a range property with the given minimum and maximum values. - -- struct drm_property \*drm_property_create_enum(struct drm_device - \*dev, int flags, const char \*name, const struct - drm_prop_enum_list \*props, int num_values); - Create an enumerated property. The ``props`` argument points to an - array of ``num_values`` value-name pairs. - -- struct drm_property \*drm_property_create_bitmask(struct - drm_device \*dev, int flags, const char \*name, const struct - drm_prop_enum_list \*props, int num_values); - Create a bitmask property. The ``props`` argument points to an array - of ``num_values`` value-name pairs. - -Properties can additionally be created as immutable, in which case they -will be read-only for applications but can be modified by the driver. To -create an immutable property drivers must set the -DRM_MODE_PROP_IMMUTABLE flag at property creation time. - -When no array of value-name pairs is readily available at property -creation time for enumerated or range properties, drivers can create the -property using the :c:func:`drm_property_create()` function and -manually add enumeration value-name pairs by calling the -:c:func:`drm_property_add_enum()` function. Care must be taken to -properly specify the property type through the ``flags`` argument. - -After creating properties drivers can attach property instances to CRTC, -connector and plane objects by calling the -:c:func:`drm_object_attach_property()`. The function takes a -pointer to the target object, a pointer to the previously created -property and an initial instance value. +Property Types and Blob Property Support +---------------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_property.c + :doc: overview + +.. kernel-doc:: include/drm/drm_property.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_property.c + :export: Blending and Z-Position properties ---------------------------------- |