linux/drivers/gpu/drm/tegra/fbdev.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2013 Avionic Design GmbH
 * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
 *
 * Based on the KMS/FB DMA helpers
 *   Copyright (C) 2012 Analog Devices Inc.
 */

#include <linux/console.h>
#include <linux/fb.h>
#include <linux/vmalloc.h>

#include <drm/drm_drv.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_modeset_helper.h>

#include "drm.h"
#include "gem.h"

static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
	struct drm_fb_helper *helper = info->par;
	struct tegra_bo *bo;
	int err;

	bo = tegra_fb_get_plane(helper->fb, 0);

	err = drm_gem_mmap_obj(&bo->gem, bo->gem.size, vma);
	if (err < 0)
		return err;

	return __tegra_gem_mmap(&bo->gem, vma);
}

static void tegra_fbdev_fb_destroy(struct fb_info *info)
{
	struct drm_fb_helper *helper = info->par;
	struct tegra_bo *bo = tegra_fb_get_plane(helper->fb, 0);

	drm_fb_helper_fini(helper);

	/* Undo the special mapping we made in fbdev probe. */
	if (bo->pages) {
		vunmap(bo->vaddr);
		bo->vaddr = NULL;
	}

	drm_client_buffer_delete(helper->buffer);
	drm_client_release(&helper->client);
}

static const struct fb_ops tegra_fb_ops = {
	.owner = THIS_MODULE,
	__FB_DEFAULT_DMAMEM_OPS_RDWR,
	DRM_FB_HELPER_DEFAULT_OPS,
	__FB_DEFAULT_DMAMEM_OPS_DRAW,
	.fb_mmap = tegra_fb_mmap,
	.fb_destroy = tegra_fbdev_fb_destroy,
};

static const struct drm_fb_helper_funcs tegra_fbdev_helper_funcs = {
};

int tegra_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
				   struct drm_fb_helper_surface_size *sizes)
{
	struct drm_client_dev *client = &helper->client;
	struct drm_device *drm = client->dev;
	struct drm_file *file = client->file;
	struct tegra_drm *tegra = drm->dev_private;
	struct fb_info *info = helper->info;
	u32 fourcc, pitch;
	u64 size;
	const struct drm_format_info *format;
	struct tegra_bo *bo;
	struct drm_gem_object *gem;
	u32 handle;
	struct drm_client_buffer *buffer;
	int err;

	fourcc = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
	format = drm_get_format_info(drm, fourcc, DRM_FORMAT_MOD_LINEAR);
	pitch = round_up(drm_format_info_min_pitch(format, 0, sizes->surface_width),
			 tegra->pitch_align);
	size = ALIGN(pitch * sizes->surface_height, PAGE_SIZE);

	bo = tegra_bo_create(drm, size, 0);
	if (IS_ERR(bo))
		return PTR_ERR(bo);
	gem = &bo->gem;

	err = drm_gem_handle_create(file, gem, &handle);
	if (err)
		goto err_drm_gem_object_put;

	buffer = drm_client_buffer_create(client, sizes->surface_width, sizes->surface_height,
					  fourcc, handle, pitch);
	if (IS_ERR(buffer)) {
		err = PTR_ERR(buffer);
		goto err_drm_gem_handle_delete;
	}

	helper->funcs = &tegra_fbdev_helper_funcs;
	helper->buffer = buffer;
	helper->fb = buffer->fb;

	info->fbops = &tegra_fb_ops;

	drm_fb_helper_fill_info(info, helper, sizes);

	if (bo->pages) {
		bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
				 pgprot_writecombine(PAGE_KERNEL));
		if (!bo->vaddr) {
			dev_err(drm->dev, "failed to vmap() framebuffer\n");
			err = -ENOMEM;
			goto err_drm_client_buffer_delete;
		}
	}

	info->flags |= FBINFO_VIRTFB;
	info->screen_buffer = bo->vaddr;
	info->screen_size = gem->size;
	info->fix.smem_start = (unsigned long)(bo->iova);
	info->fix.smem_len = gem->size;

	/* The handle is only needed for creating the framebuffer. */
	drm_gem_handle_delete(file, handle);

	/* The framebuffer still holds a reference on the GEM object. */
	drm_gem_object_put(gem);

	return 0;

err_drm_client_buffer_delete:
	drm_client_buffer_delete(buffer);
err_drm_gem_handle_delete:
	drm_gem_handle_delete(file, handle);
err_drm_gem_object_put:
	drm_gem_object_put(gem);
	return err;
}