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authorDaniel Vetter <daniel.vetter@ffwll.ch>2016-08-29 11:27:57 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-08-29 16:37:49 +0300
commitc8458c7efd01f5748e9ca74720e366d3fcc5fa97 (patch)
tree4821ebd95236e7267b06a13ddefb6f0de795b215 /include/drm/drm_property.h
parent77953bd136d2a70bca2dc93b3ccda07a2b37076f (diff)
downloadlinux-c8458c7efd01f5748e9ca74720e366d3fcc5fa97.tar.xz
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 <architt@codeaurora.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20160829082757.17913-9-daniel.vetter@ffwll.ch
Diffstat (limited to 'include/drm/drm_property.h')
-rw-r--r--include/drm/drm_property.h196
1 files changed, 185 insertions, 11 deletions
diff --git a/include/drm/drm_property.h b/include/drm/drm_property.h
index ac40069358c7..30ab289be05d 100644
--- a/include/drm/drm_property.h
+++ b/include/drm/drm_property.h
@@ -27,33 +27,192 @@
#include <linux/ctype.h>
#include <drm/drm_mode_object.h>
-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);