1. 根目录:
2. include
3. drm
4. drm_plane_helper.h

/*
 * Copyright (C) 2011-2013 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef DRM_PLANE_HELPER_H
#define DRM_PLANE_HELPER_H

#include <drm/drm_rect.h>
#include <drm/drm_crtc.h>

/*
 * Drivers that don't allow primary plane scaling may pass this macro in place
 * of the min/max scale parameters of the update checker function.
 *
 * Due to src being in 16.16 fixed point and dest being in integer pixels,
 * 1<<16 represents no scaling.
 */
#define DRM_PLANE_HELPER_NO_SCALING (1<<16)

/**
 * DOC: plane helpers
 *
 * Helper functions to assist with creation and handling of CRTC primary
 * planes.
 */

extern int drm_crtc_init(struct drm_device *dev,
			 struct drm_crtc *crtc,
			 const struct drm_crtc_funcs *funcs);

/**
 * drm_plane_helper_funcs - helper operations for CRTCs
 * @prepare_fb: prepare a framebuffer for use by the plane
 * @cleanup_fb: cleanup a framebuffer when it's no longer used by the plane
 * @atomic_check: check that a given atomic state is valid and can be applied
 * @atomic_update: apply an atomic state to the plane (mandatory)
 * @atomic_disable: disable the plane
 *
 * The helper operations are called by the mid-layer CRTC helper.
 */
struct drm_plane_helper_funcs {
	int (*prepare_fb)(struct drm_plane *plane,
			  struct drm_framebuffer *fb,
			  const struct drm_plane_state *new_state);
	void (*cleanup_fb)(struct drm_plane *plane,
			   struct drm_framebuffer *fb,
			   const struct drm_plane_state *old_state);

	int (*atomic_check)(struct drm_plane *plane,
			    struct drm_plane_state *state);
	void (*atomic_update)(struct drm_plane *plane,
			      struct drm_plane_state *old_state);
	void (*atomic_disable)(struct drm_plane *plane,
			       struct drm_plane_state *old_state);
};

static inline void drm_plane_helper_add(struct drm_plane *plane,
					const struct drm_plane_helper_funcs *funcs)
{
	plane->helper_private = funcs;
}

extern int drm_plane_helper_check_update(struct drm_plane *plane,
					 struct drm_crtc *crtc,
					 struct drm_framebuffer *fb,
					 struct drm_rect *src,
					 struct drm_rect *dest,
					 const struct drm_rect *clip,
					 int min_scale,
					 int max_scale,
					 bool can_position,
					 bool can_update_disabled,
					 bool *visible);
extern int drm_primary_helper_update(struct drm_plane *plane,
				     struct drm_crtc *crtc,
				     struct drm_framebuffer *fb,
				     int crtc_x, int crtc_y,
				     unsigned int crtc_w, unsigned int crtc_h,
				     uint32_t src_x, uint32_t src_y,
				     uint32_t src_w, uint32_t src_h);
extern int drm_primary_helper_disable(struct drm_plane *plane);
extern void drm_primary_helper_destroy(struct drm_plane *plane);
extern const struct drm_plane_funcs drm_primary_helper_funcs;

int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
			    struct drm_framebuffer *fb,
			    int crtc_x, int crtc_y,
			    unsigned int crtc_w, unsigned int crtc_h,
			    uint32_t src_x, uint32_t src_y,
			    uint32_t src_w, uint32_t src_h);
int drm_plane_helper_disable(struct drm_plane *plane);

/* For use by drm_crtc_helper.c */
int drm_plane_helper_commit(struct drm_plane *plane,
			    struct drm_plane_state *plane_state,
			    struct drm_framebuffer *old_fb);
#endif