linux/drivers/gpu/drm/drm_plane_helper.c

/*
 * Copyright (C) 2014 Intel Corporation
 *
 * DRM universal plane helper functions
 *
 * 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.
 */

#include <linux/list.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_uapi.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_encoder.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_rect.h>

#define SUBPIXEL_MASK …

/**
 * DOC: overview
 *
 * This helper library contains helpers to implement primary plane support on
 * top of the normal CRTC configuration interface.
 * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
 * plane together with the CRTC state this does not allow userspace to disable
 * the primary plane itself. The default primary plane only expose XRBG8888 and
 * ARGB8888 as valid pixel formats for the attached framebuffer.
 *
 * Drivers are highly recommended to implement proper support for primary
 * planes, and newly merged drivers must not rely upon these transitional
 * helpers.
 *
 * The plane helpers share the function table structures with other helpers,
 * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
 * the details.
 */

/*
 * Returns the connectors currently associated with a CRTC.  This function
 * should be called twice:  once with a NULL connector list to retrieve
 * the list size, and once with the properly allocated list to be filled in.
 */
static int get_connectors_for_crtc(struct drm_crtc *crtc,
				   struct drm_connector **connector_list,
				   int num_connectors)
{ … }

static 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 *dst,
					 unsigned int rotation,
					 int min_scale,
					 int max_scale,
					 bool can_position,
					 bool can_update_disabled,
					 bool *visible)
{ … }

/**
 * drm_plane_helper_update_primary - Helper for updating primary planes
 * @plane: plane to update
 * @crtc: the plane's new CRTC
 * @fb: the plane's new framebuffer
 * @crtc_x: x coordinate within CRTC
 * @crtc_y: y coordinate within CRTC
 * @crtc_w: width coordinate within CRTC
 * @crtc_h: height coordinate within CRTC
 * @src_x: x coordinate within source
 * @src_y: y coordinate within source
 * @src_w: width coordinate within source
 * @src_h: height coordinate within source
 * @ctx: modeset locking context
 *
 * This helper validates the given parameters and updates the primary plane.
 *
 * This function is only useful for non-atomic modesetting. Don't use
 * it in new drivers.
 *
 * Returns:
 * Zero on success, or an errno code otherwise.
 */
int drm_plane_helper_update_primary(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,
				    struct drm_modeset_acquire_ctx *ctx)
{ … }
EXPORT_SYMBOL(…);

/**
 * drm_plane_helper_disable_primary - Helper for disabling primary planes
 * @plane: plane to disable
 * @ctx: modeset locking context
 *
 * This helper returns an error when trying to disable the primary
 * plane.
 *
 * This function is only useful for non-atomic modesetting. Don't use
 * it in new drivers.
 *
 * Returns:
 * An errno code.
 */
int drm_plane_helper_disable_primary(struct drm_plane *plane,
				     struct drm_modeset_acquire_ctx *ctx)
{ … }
EXPORT_SYMBOL(…);

/**
 * drm_plane_helper_destroy() - Helper for primary plane destruction
 * @plane: plane to destroy
 *
 * Provides a default plane destroy handler for primary planes.  This handler
 * is called during CRTC destruction.  We disable the primary plane, remove
 * it from the DRM plane list, and deallocate the plane structure.
 */
void drm_plane_helper_destroy(struct drm_plane *plane)
{ … }
EXPORT_SYMBOL(…);