path: root/drivers/gpu/drm/drm_plane.c

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include <linux/slab.h>
#include <linux/uaccess.h>

#include <drm/drm_plane.h>
#include <drm/drm_drv.h>
#include <drm/drm_print.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_file.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_vblank.h>

#include "drm_crtc_internal.h"

/**
 * DOC: overview
 *
 * A plane represents an image source that can be blended with or overlayed on
 * top of a CRTC during the scanout process. Planes take their input data from a
 * &drm_framebuffer object. The plane itself specifies the cropping and scaling
 * of that image, and where it is placed on the visible are of a display
 * pipeline, represented by &drm_crtc. A plane can also have additional
 * properties that specify how the pixels are positioned and blended, like
 * rotation or Z-position. All these properties are stored in &drm_plane_state.
 *
 * To create a plane, a KMS drivers allocates and zeroes an instances of
 * &struct drm_plane (possibly as part of a larger structure) and registers it
 * with a call to drm_universal_plane_init().
 *
 * Cursor and overlay planes are optional. All drivers should provide one
 * primary plane per CRTC to avoid surprising userspace too much. See enum
 * drm_plane_type for a more in-depth discussion of these special uapi-relevant
 * plane types. Special planes are associated with their CRTC by calling
 * drm_crtc_init_with_planes().
 *
 * The type of a plane is exposed in the immutable "type" enumeration property,
 * which has one of the following values: "Overlay", "Primary", "Cursor".
 */

static unsigned int drm_num_planes(struct drm_device *dev)
{
	unsigned int num = 0;
	struct drm_plane *tmp;

	drm_for_each_plane(tmp, dev) {
		num++;
	}

	return num;
}

static inline u32 *
formats_ptr(struct drm_format_modifier_blob *blob)
{
	return (u32 *)(((char *)blob) + blob->formats_offset);
}

static inline struct drm_format_modifier *
modifiers_ptr(struct drm_format_modifier_blob *blob)
{
	return (struct drm_format_modifier *)(((char *)blob) + blob->modifiers_offset);
}

static int create_in_format_blob(struct drm_device *dev, struct drm_plane *plane)
{
	const struct drm_mode_config *config = &dev->mode_config;
	struct drm_property_blob *blob;
	struct drm_format_modifier *mod;
	size_t blob_size, formats_size, modifiers_size;
	struct drm_format_modifier_blob *blob_data;
	unsigned int i, j;

	formats_size = sizeof(__u32) * plane->format_count;
	if (WARN_ON(!formats_size)) {
		/* 0 formats are never expected */
		return 0;
	}

	modifiers_size =
		sizeof(struct drm_format_modifier) * plane->modifier_count;

	blob_size = sizeof(struct drm_format_modifier_blob);
	/* Modifiers offset is a pointer to a struct with a 64 bit field so it
	 * should be naturally aligned to 8B.
	 */
	BUILD_BUG_ON(sizeof(struct drm_format_modifier_blob) % 8);
	blob_size += ALIGN(formats_size, 8);
	blob_size += modifiers_size;

	blob = drm_property_create_blob(dev, blob_size, NULL);
	if (IS_ERR(blob))
		return -1;

	blob_data = blob->data;
	blob_data->version = FORMAT_BLOB_CURRENT;
	blob_data->count_formats = plane->format_count;
	blob_data->formats_offset = sizeof(struct drm_format_modifier_blob);
	blob_data->count_modifiers = plane->modifier_count;

	blob_data->modifiers_offset =
		ALIGN(blob_data->formats_offset + formats_size, 8);

	memcpy(formats_ptr(blob_data), plane->format_types, formats_size);

	/* If we can't determine support, just bail */
	if (!plane->funcs->format_mod_supported)
		goto done;

	mod = modifiers_ptr(blob_data);
	for (i = 0; i < plane->modifier_count; i++) {
		for (j = 0; j < plane->format_count; j++) {
			if (plane->funcs->format_mod_supported(plane