From: Laurent Pinchart Date: Sat, 22 Jun 2013 14:10:30 +0000 (+0200) Subject: drm/doc: Document the KMS property API X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=421cda3e324fce40e3f7abdf3d31cae1d0deddcd;p=linux-beck.git drm/doc: Document the KMS property API Signed-off-by: Laurent Pinchart Reviewed-by: Alex Deucher Signed-off-by: Dave Airlie --- diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index cea420dc712d..4d54ac8b2032 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -1235,6 +1235,15 @@ int max_width, max_height; Miscellaneous + + void (*set_property)(struct drm_crtc *crtc, + struct drm_property *property, uint64_t value); + + Set the value of the given CRTC property to + value. See + for more information about properties. + + void (*gamma_set)(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b, uint32_t start, uint32_t size); @@ -1385,6 +1394,15 @@ int max_width, max_height; . + + void (*set_property)(struct drm_plane *plane, + struct drm_property *property, uint64_t value); + + Set the value of the given plane property to + value. See + for more information about properties. + + @@ -1593,6 +1611,15 @@ int max_width, max_height; Miscellaneous + + void (*set_property)(struct drm_connector *connector, + struct drm_property *property, uint64_t value); + + Set the value of the given connector property to + value. See + for more information about properties. + + void (*destroy)(struct drm_connector *connector); @@ -2187,6 +2214,122 @@ void intel_crt_init(struct drm_device *dev) + + + + 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 propery + 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 drm_property_create function + and manually add enumeration value-name pairs by calling the + 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 + 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. + + +