drm/gem-fb-helper: Improve documentation (2e187b20) · Commits · e / devices / android_kernel_teracube_emerald

drivers/gpu/drm/drm_gem_framebuffer_helper.c

+52 −30

Original line number	Diff line number	Diff line
		@@ -27,19 +27,24 @@
		* DOC: overview
		*
		* This library provides helpers for drivers that don't subclass
		* &drm_framebuffer and and use &drm_gem_object for their backing storage.
		* &drm_framebuffer and use &drm_gem_object for their backing storage.
		*
		* Drivers without additional needs to validate framebuffers can simply use
		* drm_gem_fb_create() and everything is wired up automatically. But all
		* parts can be used individually.
		* drm_gem_fb_create() and everything is wired up automatically. Other drivers
		* can use all parts independently.
		*/

		/**
		* drm_gem_fb_get_obj() - Get GEM object for framebuffer
		* @fb: The framebuffer
		* @plane: Which plane
		* drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
		* @fb: Framebuffer
		* @plane: Plane index
		*
		* Returns the GEM object for given framebuffer.
		* No additional reference is taken beyond the one that the &drm_frambuffer
		* already holds.
		*
		* Returns:
		* Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
		* if it does not exist.
		*/
		struct drm_gem_object drm_gem_fb_get_obj(struct drm_framebuffer fb,
		unsigned int plane)
		@@ -82,7 +87,7 @@ drm_gem_fb_alloc(struct drm_device *dev,

		/**
		* drm_gem_fb_destroy - Free GEM backed framebuffer
		* @fb: DRM framebuffer
		* @fb: Framebuffer
		*
		* Frees a GEM backed framebuffer with its backing buffer(s) and the structure
		* itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
		@@ -102,12 +107,13 @@ EXPORT_SYMBOL(drm_gem_fb_destroy);

		/**
		* drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
		* @fb: DRM framebuffer
		* @file: drm file
		* @handle: handle created
		* @fb: Framebuffer
		* @file: DRM file to register the handle for
		* @handle: Pointer to return the created handle
		*
		* This function creates a handle for the GEM object backing the framebuffer.
		* Drivers can use this as their &drm_framebuffer_funcs->create_handle
		* callback.
		* callback. The GETFB IOCTL calls into this callback.
		*
		* Returns:
		* 0 on success or a negative error code on failure.
		@@ -120,18 +126,21 @@ int drm_gem_fb_create_handle(struct drm_framebuffer fb, struct drm_file file,
		EXPORT_SYMBOL(drm_gem_fb_create_handle);

		/**
		* drm_gem_fb_create_with_funcs() - helper function for the
		* drm_gem_fb_create_with_funcs() - Helper function for the
		* &drm_mode_config_funcs.fb_create
		* callback
		* @dev: DRM device
		* @file: drm file for the ioctl call
		* @mode_cmd: metadata from the userspace fb creation request
		* @file: DRM file that holds the GEM handle(s) backing the framebuffer
		* @mode_cmd: Metadata from the userspace framebuffer creation request
		* @funcs: vtable to be used for the new framebuffer object
		*
		* This can be used to set &drm_framebuffer_funcs for drivers that need the
		* &drm_framebuffer_funcs.dirty callback. Use drm_gem_fb_create() if you don't
		* need to change &drm_framebuffer_funcs.
		* The function does buffer size validation.
		*
		* Returns:
		* Pointer to a &drm_framebuffer on success or an error pointer on failure.
		*/
		struct drm_framebuffer *
		drm_gem_fb_create_with_funcs(struct drm_device dev, struct drm_file file,
		@@ -192,15 +201,26 @@ static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
		};

		/**
		* drm_gem_fb_create() - &drm_mode_config_funcs.fb_create callback function
		* drm_gem_fb_create() - Helper function for the
		* &drm_mode_config_funcs.fb_create callback
		* @dev: DRM device
		* @file: drm file for the ioctl call
		* @mode_cmd: metadata from the userspace fb creation request
		* @file: DRM file that holds the GEM handle(s) backing the framebuffer
		* @mode_cmd: Metadata from the userspace framebuffer creation request
		*
		* This function creates a new framebuffer object described by
		* &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
		* backing the framebuffer.
		*
		* If your hardware has special alignment or pitch requirements these should be
		* checked before calling this function. The function does buffer size
		* validation. Use drm_gem_fb_create_with_funcs() if you need to set
		* &drm_framebuffer_funcs.dirty.
		*
		* Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
		* The ADDFB2 IOCTL calls into this callback.
		*
		* Returns:
		* Pointer to a &drm_framebuffer on success or an error pointer on failure.
		*/
		struct drm_framebuffer *
		drm_gem_fb_create(struct drm_device dev, struct drm_file file,
		@@ -212,15 +232,15 @@ drm_gem_fb_create(struct drm_device dev, struct drm_file file,
		EXPORT_SYMBOL_GPL(drm_gem_fb_create);

		/**
		* drm_gem_fb_prepare_fb() - Prepare gem framebuffer
		* @plane: Which plane
		* @state: Plane state attach fence to
		* drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer
		* @plane: Plane
		* @state: Plane state the fence will be attached to
		*
		* This can be used as the &drm_plane_helper_funcs.prepare_fb hook.
		*
		* This function checks if the plane FB has an dma-buf attached, extracts
		* the exclusive fence and attaches it to plane state for the atomic helper
		* to wait on.
		* This function prepares a GEM backed framebuffer for scanout by checking if
		* the plane framebuffer has a DMA-BUF attached. If it does, it extracts the
		* exclusive fence and attaches it to the plane state for the atomic helper to
		* wait on. This function can be used as the &drm_plane_helper_funcs.prepare_fb
		* callback.
		*
		* There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple
		* gem based framebuffer drivers which have their buffers always pinned in
		@@ -246,17 +266,19 @@ int drm_gem_fb_prepare_fb(struct drm_plane *plane,
		EXPORT_SYMBOL_GPL(drm_gem_fb_prepare_fb);

		/**
		* drm_gem_fbdev_fb_create - Create a drm_framebuffer for fbdev emulation
		* drm_gem_fbdev_fb_create - Create a GEM backed &drm_framebuffer for fbdev
		* emulation
		* @dev: DRM device
		* @sizes: fbdev size description
		* @pitch_align: optional pitch alignment
		* @pitch_align: Optional pitch alignment
		* @obj: GEM object backing the framebuffer
		* @funcs: vtable to be used for the new framebuffer object
		*
		* This function creates a framebuffer for use with fbdev emulation.
		* This function creates a framebuffer from a &drm_fb_helper_surface_size
		* description for use in the &drm_fb_helper_funcs.fb_probe callback.
		*
		* Returns:
		* Pointer to a drm_framebuffer on success or an error pointer on failure.
		* Pointer to a &drm_framebuffer on success or an error pointer on failure.
		*/
		struct drm_framebuffer *
		drm_gem_fbdev_fb_create(struct drm_device *dev,