drm: document drm_mode_get_property (6e5b47a4) · Commits · EulixOS / Software / Kernel

Documentation/gpu/drm-kms.rst

+2 −0

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	@@ -159,6 +159,8 @@ KMS Core Structures and Functions
	.. kernel-doc:: drivers/gpu/drm/drm_mode_config.c		.. kernel-doc:: drivers/gpu/drm/drm_mode_config.c
	:export:		:export:

			.. _kms_base_object_abstraction:

	Modeset Base Object Abstraction		Modeset Base Object Abstraction
	===============================		===============================

include/uapi/drm/drm_mode.h

+56 −4

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	@@ -541,22 +541,74 @@ struct drm_mode_get_connector {
	*/		*/
	#define DRM_MODE_PROP_ATOMIC 0x80000000		#define DRM_MODE_PROP_ATOMIC 0x80000000

			/**
			* struct drm_mode_property_enum - Description for an enum/bitfield entry.
			* @value: numeric value for this enum entry.
			* @name: symbolic name for this enum entry.
			*
			* See struct drm_property_enum for details.
			*/
	struct drm_mode_property_enum {		struct drm_mode_property_enum {
	__u64 value;		__u64 value;
	char name[DRM_PROP_NAME_LEN];		char name[DRM_PROP_NAME_LEN];
	};		};

			/**
			* struct drm_mode_get_property - Get property metadata.
			*
			* User-space can perform a GETPROPERTY ioctl to retrieve information about a
			* property. The same property may be attached to multiple objects, see
			* "Modeset Base Object Abstraction".
			*
			* The meaning of the @values_ptr field changes depending on the property type.
			* See &drm_property.flags for more details.
			*
			* The @enum_blob_ptr and @count_enum_blobs fields are only meaningful when the
			* property has the type &DRM_MODE_PROP_ENUM or &DRM_MODE_PROP_BITMASK. For
			* backwards compatibility, the kernel will always set @count_enum_blobs to
			* zero when the property has the type &DRM_MODE_PROP_BLOB. User-space must
			* ignore these two fields if the property has a different type.
			*
			* User-space is expected to retrieve values and enums by performing this ioctl
			* at least twice: the first time to retrieve the number of elements, the
			* second time to retrieve the elements themselves.
			*
			* To retrieve the number of elements, set @count_values and @count_enum_blobs
			* to zero, then call the ioctl. @count_values will be updated with the number
			* of elements. If the property has the type &DRM_MODE_PROP_ENUM or
			* &DRM_MODE_PROP_BITMASK, @count_enum_blobs will be updated as well.
			*
			* To retrieve the elements themselves, allocate an array for @values_ptr and
			* set @count_values to its capacity. If the property has the type
			* &DRM_MODE_PROP_ENUM or &DRM_MODE_PROP_BITMASK, allocate an array for
			* @enum_blob_ptr and set @count_enum_blobs to its capacity. Calling the ioctl
			* again will fill the arrays.
			*/
	struct drm_mode_get_property {		struct drm_mode_get_property {
	__u64 values_ptr; /* values and blob lengths */		/** @values_ptr: Pointer to a ``__u64`` array. */
	__u64 enum_blob_ptr; /* enum and blob id ptrs */		__u64 values_ptr;
			/** @enum_blob_ptr: Pointer to a struct drm_mode_property_enum array. */
			__u64 enum_blob_ptr;

			/**
			* @prop_id: Object ID of the property which should be retrieved. Set
			* by the caller.
			*/
	__u32 prop_id;		__u32 prop_id;
			/**
			* @flags: ``DRM_MODE_PROP_*`` bitfield. See &drm_property.flags for
			* a definition of the flags.
			*/
	__u32 flags;		__u32 flags;
			/**
			* @name: Symbolic property name. User-space should use this field to
			* recognize properties.
			*/
	char name[DRM_PROP_NAME_LEN];		char name[DRM_PROP_NAME_LEN];

			/** @count_values: Number of elements in @values_ptr. */
	__u32 count_values;		__u32 count_values;
	/* This is only used to count enum values, not blobs. The _blobs is		/** @count_enum_blobs: Number of elements in @enum_blob_ptr. */
	* simply because of a historical reason, i.e. backwards compat. */
	__u32 count_enum_blobs;		__u32 count_enum_blobs;
	};		};