From c8458c7efd01f5748e9ca74720e366d3fcc5fa97 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 29 Aug 2016 10:27:57 +0200 Subject: drm/doc: Polish docs for drm_property&drm_property_blob - remove kerneldoc for drm-internal functions - drm_property_replace_global_blob isn't actually atomic, and doesn't need to be. Update docs&comments to match - document all the types and try to link things a bit better - nits all over v2: Appease checkpatch in the moved code (Archit) Reviewed-by: Archit Taneja Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20160829082757.17913-9-daniel.vetter@ffwll.ch --- include/drm/drm_property.h | 196 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 185 insertions(+), 11 deletions(-) (limited to 'include/drm') diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h index ac40069..30ab289 100644 --- a/include/drm/drm_property.h +++ b/include/drm/drm_property.h @@ -27,33 +27,192 @@ #include #include -struct drm_property_blob { - struct drm_mode_object base; - struct drm_device *dev; - struct list_head head_global; - struct list_head head_file; - size_t length; - unsigned char data[]; -}; - +/** + * struct drm_property_enum - symbolic values for enumerations + * @value: numeric property value for this enum entry + * @head: list of enum values, linked to enum_list in &drm_property + * @name: symbolic name for the enum + * + * For enumeration and bitmask properties this structure stores the symbolic + * decoding for each value. This is used for example for the rotation property. + */ struct drm_property_enum { uint64_t value; struct list_head head; char name[DRM_PROP_NAME_LEN]; }; +/** + * struct drm_property - modeset object property + * + * This structure represent a modeset object property. It combines both the name + * of the property with the set of permissible values. This means that when a + * driver wants to use a property with the same name on different objects, but + * with different value ranges, then it must create property for each one. An + * example would be rotation of &drm_plane, when e.g. the primary plane cannot + * be rotated. But if both the name and the value range match, then the same + * property structure can be instantiated multiple times for the same object. + * Userspace must be able to cope with this and cannot assume that the same + * symbolic property will have the same modeset object ID on all modeset + * objects. + * + * Properties are created by one of the special functions, as explained in + * detail in the @flags structure member. + * + * To actually expose a property it must be attached to each object using + * drm_object_attach_property(). Currently properties can only be attached to + * &drm_connector, &drm_crtc and &drm_plane. + * + * Properties are also used as the generic metadatatransport for the atomic + * IOCTL. Everything that was set directly in structures in the legacy modeset + * IOCTLs (like the plane source or destination windows, or e.g. the links to + * the CRTC) is exposed as a property with the DRM_MODE_PROP_ATOMIC flag set. + */ struct drm_property { + /** + * @head: per-device list of properties, for cleanup. + */ struct list_head head; + + /** + * @base: base KMS object + */ struct drm_mode_object base; + + /** + * @flags: + * + * Property flags and type. A property needs to be one of the following + * types: + * + * DRM_MODE_PROP_RANGE + * Range properties report their minimum and maximum admissible unsigned values. + * The KMS core verifies that values set by application fit in that + * range. The range is unsigned. Range properties are created using + * drm_property_create_range(). + * + * DRM_MODE_PROP_SIGNED_RANGE + * Range properties report their minimum and maximum admissible unsigned values. + * The KMS core verifies that values set by application fit in that + * range. The range is signed. Range properties are created using + * drm_property_create_signed_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. Enum + * properties are created using drm_property_create_enum(). + * + * 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. Bitmask properties are created using + * drm_property_create_bitmask(). + * + * DRM_MODE_PROB_OBJECT + * Object properties are used to link modeset objects. This is used + * extensively in the atomic support to create the display pipeline, + * by linking &drm_framebuffer to &drm_plane, &drm_plane to + * &drm_crtc and &drm_connector to &drm_crtc. An object property can + * only link to a specific type of &drm_mode_object, this limit is + * enforced by the core. Object properties are created using + * drm_property_create_object(). + * + * Object properties work like blob properties, but in a more + * general fashion. They are limited to atomic drivers and must have + * the DRM_MODE_PROP_ATOMIC flag set. + * + * 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 created by calling + * drm_property_create() with DRM_MODE_PROP_BLOB as the type. + * + * Actual blob objects to contain blob data are created using + * drm_property_create_blob(), or through the corresponding IOCTL. + * + * Besides the built-in limit to only accept blob objects blob + * properties work exactly like object properties. The only reasons + * blob properties exist is backwards compatibility with existing + * userspace. + * + * In addition a property can have any combination of the below flags: + * + * DRM_MODE_PROP_ATOMIC + * Set for properties which encode atomic modeset state. Such + * properties are not exposed to legacy userspace. + * + * DRM_MODE_PROP_IMMUTABLE + * Set for properties where userspace cannot be changed by + * userspace. The kernel is allowed to update the value of these + * properties. This is generally used to expose probe state to + * usersapce, e.g. the EDID, or the connector path property on DP + * MST sinks. + */ uint32_t flags; + + /** + * @name: symbolic name of the properties + */ char name[DRM_PROP_NAME_LEN]; + + /** + * @num_values: size of the @values array. + */ uint32_t num_values; + + /** + * @values: + * + * Array with limits and values for the property. The + * interpretation of these limits is dependent upon the type per @flags. + */ uint64_t *values; + + /** + * @dev: DRM device + */ struct drm_device *dev; + /** + * @enum_list: + * + * List of &drm_prop_enum_list structures with the symbolic names for + * enum and bitmask values. + */ struct list_head enum_list; }; +/** + * struct drm_property_blob - Blob data for &drm_property + * @base: base KMS object + * @dev: DRM device + * @head_global: entry on the global blob list in &drm_mode_config + * property_blob_list. + * @head_file: entry on the per-file blob list in &drm_file blobs list. + * @length: size of the blob in bytes, invariant over the lifetime of the object + * @data: actual data, embedded at the end of this structure + * + * Blobs are used to store bigger values than what fits directly into the 64 + * bits available for a &drm_property. + * + * Blobs are reference counted using drm_property_reference_blob() and + * drm_property_unreference_blob(). They are created using + * drm_property_create_blob(). + */ +struct drm_property_blob { + struct drm_mode_object base; + struct drm_device *dev; + struct list_head head_global; + struct list_head head_file; + size_t length; + unsigned char data[]; +}; + struct drm_prop_enum_list { int type; char *name; @@ -61,8 +220,16 @@ struct drm_prop_enum_list { #define obj_to_property(x) container_of(x, struct drm_property, base) +/** + * drm_property_type_is - check the type of a property + * @property: property to check + * @type: property type to compare with + * + * This is a helper function becauase the uapi encoding of property types is + * a bit special for historical reasons. + */ static inline bool drm_property_type_is(struct drm_property *property, - uint32_t type) + uint32_t type) { /* instanceof for props.. handles extended type vs original types: */ if (property->flags & DRM_MODE_PROP_EXTENDED_TYPE) @@ -109,8 +276,15 @@ int drm_property_replace_global_blob(struct drm_device *dev, struct drm_property_blob *drm_property_reference_blob(struct drm_property_blob *blob); void drm_property_unreference_blob(struct drm_property_blob *blob); +/** + * drm_connector_find - find property object + * @dev: DRM device + * @id: property object id + * + * This function looks up the property object specified by id and returns it. + */ static inline struct drm_property *drm_property_find(struct drm_device *dev, - uint32_t id) + uint32_t id) { struct drm_mode_object *mo; mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_PROPERTY); -- cgit v1.1