linux-imx

// SPDX-License-Identifier: GPL-2.0 OR MIT

/**************************************************************************

 *

 * Copyright (c) 2018 VMware, Inc., Palo Alto, CA., USA

 * All Rights Reserved.

 *

 * 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,

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 * 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,

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 *

 * Authors:

 * Deepak Rawat <drawat@vmware.com>

 * Rob Clark <robdclark@gmail.com>

 *

 **************************************************************************/

​

#include <drm/drm_atomic.h>

#include <drm/drm_damage_helper.h>

#include <drm/drm_device.h>

​

/**

 * DOC: overview

 *

 * FB_DAMAGE_CLIPS is an optional plane property which provides a means to

 * specify a list of damage rectangles on a plane in framebuffer coordinates of

 * the framebuffer attached to the plane. In current context damage is the area

 * of plane framebuffer that has changed since last plane update (also called

 * page-flip), irrespective of whether currently attached framebuffer is same as

 * framebuffer attached during last plane update or not.

 *

 * FB_DAMAGE_CLIPS is a hint to kernel which could be helpful for some drivers

 * to optimize internally especially for virtual devices where each framebuffer

 * change needs to be transmitted over network, usb, etc.

 *

 * Since FB_DAMAGE_CLIPS is a hint so it is an optional property. User-space can

 * ignore damage clips property and in that case driver will do a full plane

 * update. In case damage clips are provided then it is guaranteed that the area

 * inside damage clips will be updated to plane. For efficiency driver can do

 * full update or can update more than specified in damage clips. Since driver

 * is free to read more, user-space must always render the entire visible

 * framebuffer. Otherwise there can be corruptions. Also, if a user-space

 * provides damage clips which doesn't encompass the actual damage to

 * framebuffer (since last plane update) can result in incorrect rendering.

 *

 * FB_DAMAGE_CLIPS is a blob property with the layout of blob data is simply an

 * array of &drm_mode_rect. Unlike plane &drm_plane_state.src coordinates,

 * damage clips are not in 16.16 fixed point. Similar to plane src in