drivers/gpu/drm/tegra/fb.c - linux - Git at Google

 // 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 CMA helpers
  *   Copyright (C) 2012 Analog Devices Inc.
  */

 #include <linux/console.h>

 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_modeset_helper.h>

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

 #ifdef CONFIG_DRM_FBDEV_EMULATION
 static inline struct tegra_fbdev *to_tegra_fbdev(struct drm_fb_helper *helper)
 {
 	return container_of(helper, struct tegra_fbdev, base);
 }
 #endif

 struct tegra_bo *tegra_fb_get_plane(struct drm_framebuffer *framebuffer,
 				    unsigned int index)
 {
 	return to_tegra_bo(drm_gem_fb_get_obj(framebuffer, index));
 }

 bool tegra_fb_is_bottom_up(struct drm_framebuffer *framebuffer)
 {
 	struct tegra_bo *bo = tegra_fb_get_plane(framebuffer, 0);

 	if (bo->flags & TEGRA_BO_BOTTOM_UP)
 		return true;

 	return false;
 }

 int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
 			struct tegra_bo_tiling *tiling)
 {
 	uint64_t modifier = framebuffer->modifier;

 	switch (modifier) {
 	case DRM_FORMAT_MOD_LINEAR:
 		tiling->mode = TEGRA_BO_TILING_MODE_PITCH;
 		tiling->value = 0;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_TEGRA_TILED:
 		tiling->mode = TEGRA_BO_TILING_MODE_TILED;
 		tiling->value = 0;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(0):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 0;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(1):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 1;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(2):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 2;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(3):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 3;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(4):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 4;
 		break;

 	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(5):
 		tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
 		tiling->value = 5;
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static const struct drm_framebuffer_funcs tegra_fb_funcs = {
 	.destroy = drm_gem_fb_destroy,
 	.create_handle = drm_gem_fb_create_handle,
 };

 static struct drm_framebuffer *tegra_fb_alloc(struct drm_device *drm,
 					      const struct drm_mode_fb_cmd2 *mode_cmd,
 					      struct tegra_bo **planes,
 					      unsigned int num_planes)
 {
 	struct drm_framebuffer *fb;
 	unsigned int i;
 	int err;

 	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
 	if (!fb)
 		return ERR_PTR(-ENOMEM);

 	drm_helper_mode_fill_fb_struct(drm, fb, mode_cmd);

 	for (i = 0; i < fb->format->num_planes; i++)
 		fb->obj[i] = &planes[i]->gem;

 	err = drm_framebuffer_init(drm, fb, &tegra_fb_funcs);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to initialize framebuffer: %d\n",
 			err);
 		kfree(fb);
 		return ERR_PTR(err);
 	}

 	return fb;
 }

 struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 					struct drm_file *file,
 					const struct drm_mode_fb_cmd2 *cmd)
 {
 	const struct drm_format_info *info = drm_get_format_info(drm, cmd);
 	struct tegra_bo *planes[4];
 	struct drm_gem_object *gem;
 	struct drm_framebuffer *fb;
 	unsigned int i;
 	int err;

 	for (i = 0; i < info->num_planes; i++) {
 		unsigned int width = cmd->width / (i ? info->hsub : 1);
 		unsigned int height = cmd->height / (i ? info->vsub : 1);
 		unsigned int size, bpp;

 		gem = drm_gem_object_lookup(file, cmd->handles[i]);
 		if (!gem) {
 			err = -ENXIO;
 			goto unreference;
 		}

 		bpp = info->cpp[i];

 		size = (height - 1) * cmd->pitches[i] +
 		       width * bpp + cmd->offsets[i];

 		if (gem->size < size) {
 			err = -EINVAL;
 			goto unreference;
 		}

 		planes[i] = to_tegra_bo(gem);
 	}

 	fb = tegra_fb_alloc(drm, cmd, planes, i);
 	if (IS_ERR(fb)) {
 		err = PTR_ERR(fb);
 		goto unreference;
 	}

 	return fb;

 unreference:
 	while (i--)
 		drm_gem_object_put(&planes[i]->gem);

 	return ERR_PTR(err);
 }

 #ifdef CONFIG_DRM_FBDEV_EMULATION
 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 const struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
 	.fb_fillrect = drm_fb_helper_sys_fillrect,
 	.fb_copyarea = drm_fb_helper_sys_copyarea,
 	.fb_imageblit = drm_fb_helper_sys_imageblit,
 	.fb_mmap = tegra_fb_mmap,
 };

 static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 			     struct drm_fb_helper_surface_size *sizes)
 {
 	struct tegra_fbdev *fbdev = to_tegra_fbdev(helper);
 	struct tegra_drm *tegra = helper->dev->dev_private;
 	struct drm_device *drm = helper->dev;
 	struct drm_mode_fb_cmd2 cmd = { 0 };
 	unsigned int bytes_per_pixel;
 	struct drm_framebuffer *fb;
 	unsigned long offset;
 	struct fb_info *info;
 	struct tegra_bo *bo;
 	size_t size;
 	int err;

 	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);

 	cmd.width = sizes->surface_width;
 	cmd.height = sizes->surface_height;
 	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
 				  tegra->pitch_align);

 	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 						     sizes->surface_depth);

 	size = cmd.pitches[0] * cmd.height;

 	bo = tegra_bo_create(drm, size, 0);
 	if (IS_ERR(bo))
 		return PTR_ERR(bo);

 	info = drm_fb_helper_alloc_fbi(helper);
 	if (IS_ERR(info)) {
 		dev_err(drm->dev, "failed to allocate framebuffer info\n");
 		drm_gem_object_put(&bo->gem);
 		return PTR_ERR(info);
 	}

 	fbdev->fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
 	if (IS_ERR(fbdev->fb)) {
 		err = PTR_ERR(fbdev->fb);
 		dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
 			err);
 		drm_gem_object_put(&bo->gem);
 		return PTR_ERR(fbdev->fb);
 	}

 	fb = fbdev->fb;
 	helper->fb = fb;
 	helper->fbdev = info;

 	info->fbops = &tegra_fb_ops;

 	drm_fb_helper_fill_info(info, helper, sizes);

 	offset = info->var.xoffset * bytes_per_pixel +
 		 info->var.yoffset * fb->pitches[0];

 	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 destroy;
 		}
 	}

 	drm->mode_config.fb_base = (resource_size_t)bo->iova;
 	info->screen_base = (void __iomem *)bo->vaddr + offset;
 	info->screen_size = size;
 	info->fix.smem_start = (unsigned long)(bo->iova + offset);
 	info->fix.smem_len = size;

 	return 0;

 destroy:
 	drm_framebuffer_remove(fb);
 	return err;
 }

 static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
 	.fb_probe = tegra_fbdev_probe,
 };

 static struct tegra_fbdev *tegra_fbdev_create(struct drm_device *drm)
 {
 	struct tegra_fbdev *fbdev;

 	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
 	if (!fbdev) {
 		dev_err(drm->dev, "failed to allocate DRM fbdev\n");
 		return ERR_PTR(-ENOMEM);
 	}

 	drm_fb_helper_prepare(drm, &fbdev->base, &tegra_fb_helper_funcs);

 	return fbdev;
 }

 static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
 {
 	kfree(fbdev);
 }

 static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
 			    unsigned int preferred_bpp,
 			    unsigned int num_crtc,
 			    unsigned int max_connectors)
 {
 	struct drm_device *drm = fbdev->base.dev;
 	int err;

 	err = drm_fb_helper_init(drm, &fbdev->base);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
 			err);
 		return err;
 	}

 	err = drm_fb_helper_initial_config(&fbdev->base, preferred_bpp);
 	if (err < 0) {
 		dev_err(drm->dev, "failed to set initial configuration: %d\n",
 			err);
 		goto fini;
 	}

 	return 0;

 fini:
 	drm_fb_helper_fini(&fbdev->base);
 	return err;
 }

 static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
 {
 	drm_fb_helper_unregister_fbi(&fbdev->base);

 	if (fbdev->fb) {
 		struct tegra_bo *bo = tegra_fb_get_plane(fbdev->fb, 0);

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

 		drm_framebuffer_remove(fbdev->fb);
 	}

 	drm_fb_helper_fini(&fbdev->base);
 	tegra_fbdev_free(fbdev);
 }
 #endif

 int tegra_drm_fb_prepare(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	struct tegra_drm *tegra = drm->dev_private;

 	tegra->fbdev = tegra_fbdev_create(drm);
 	if (IS_ERR(tegra->fbdev))
 		return PTR_ERR(tegra->fbdev);
 #endif

 	return 0;
 }

 void tegra_drm_fb_free(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	struct tegra_drm *tegra = drm->dev_private;

 	tegra_fbdev_free(tegra->fbdev);
 #endif
 }

 int tegra_drm_fb_init(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	struct tegra_drm *tegra = drm->dev_private;
 	int err;

 	err = tegra_fbdev_init(tegra->fbdev, 32, drm->mode_config.num_crtc,
 			       drm->mode_config.num_connector);
 	if (err < 0)
 		return err;
 #endif

 	return 0;
 }

 void tegra_drm_fb_exit(struct drm_device *drm)
 {
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	struct tegra_drm *tegra = drm->dev_private;

 	tegra_fbdev_exit(tegra->fbdev);
 #endif
 }
	// 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 CMA helpers
	* Copyright (C) 2012 Analog Devices Inc.
	*/

	#include <linux/console.h>

	#include <drm/drm_fourcc.h>
	#include <drm/drm_gem_framebuffer_helper.h>
	#include <drm/drm_modeset_helper.h>

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

	#ifdef CONFIG_DRM_FBDEV_EMULATION
	static inline struct tegra_fbdev to_tegra_fbdev(struct drm_fb_helper helper)
	{
	return container_of(helper, struct tegra_fbdev, base);
	}
	#endif

	struct tegra_bo tegra_fb_get_plane(struct drm_framebuffer framebuffer,
	unsigned int index)
	{
	return to_tegra_bo(drm_gem_fb_get_obj(framebuffer, index));
	}

	bool tegra_fb_is_bottom_up(struct drm_framebuffer *framebuffer)
	{
	struct tegra_bo *bo = tegra_fb_get_plane(framebuffer, 0);

	if (bo->flags & TEGRA_BO_BOTTOM_UP)
	return true;

	return false;
	}

	int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
	struct tegra_bo_tiling *tiling)
	{
	uint64_t modifier = framebuffer->modifier;

	switch (modifier) {
	case DRM_FORMAT_MOD_LINEAR:
	tiling->mode = TEGRA_BO_TILING_MODE_PITCH;
	tiling->value = 0;
	break;

	case DRM_FORMAT_MOD_NVIDIA_TEGRA_TILED:
	tiling->mode = TEGRA_BO_TILING_MODE_TILED;
	tiling->value = 0;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(0):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 0;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(1):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 1;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(2):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 2;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(3):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 3;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(4):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 4;
	break;

	case DRM_FORMAT_MOD_NVIDIA_16BX2_BLOCK(5):
	tiling->mode = TEGRA_BO_TILING_MODE_BLOCK;
	tiling->value = 5;
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static const struct drm_framebuffer_funcs tegra_fb_funcs = {
	.destroy = drm_gem_fb_destroy,
	.create_handle = drm_gem_fb_create_handle,
	};

	static struct drm_framebuffer tegra_fb_alloc(struct drm_device drm,
	const struct drm_mode_fb_cmd2 *mode_cmd,
	struct tegra_bo **planes,
	unsigned int num_planes)
	{
	struct drm_framebuffer *fb;
	unsigned int i;
	int err;

	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
	if (!fb)
	return ERR_PTR(-ENOMEM);

	drm_helper_mode_fill_fb_struct(drm, fb, mode_cmd);

	for (i = 0; i < fb->format->num_planes; i++)
	fb->obj[i] = &planes[i]->gem;

	err = drm_framebuffer_init(drm, fb, &tegra_fb_funcs);
	if (err < 0) {
	dev_err(drm->dev, "failed to initialize framebuffer: %d\n",
	err);
	kfree(fb);
	return ERR_PTR(err);
	}

	return fb;
	}

	struct drm_framebuffer tegra_fb_create(struct drm_device drm,
	struct drm_file *file,
	const struct drm_mode_fb_cmd2 *cmd)
	{
	const struct drm_format_info *info = drm_get_format_info(drm, cmd);
	struct tegra_bo *planes[4];
	struct drm_gem_object *gem;
	struct drm_framebuffer *fb;
	unsigned int i;
	int err;

	for (i = 0; i < info->num_planes; i++) {
	unsigned int width = cmd->width / (i ? info->hsub : 1);
	unsigned int height = cmd->height / (i ? info->vsub : 1);
	unsigned int size, bpp;

	gem = drm_gem_object_lookup(file, cmd->handles[i]);
	if (!gem) {
	err = -ENXIO;
	goto unreference;
	}

	bpp = info->cpp[i];

	size = (height - 1) * cmd->pitches[i] +
	width * bpp + cmd->offsets[i];

	if (gem->size < size) {
	err = -EINVAL;
	goto unreference;
	}

	planes[i] = to_tegra_bo(gem);
	}

	fb = tegra_fb_alloc(drm, cmd, planes, i);
	if (IS_ERR(fb)) {
	err = PTR_ERR(fb);
	goto unreference;
	}

	return fb;

	unreference:
	while (i--)
	drm_gem_object_put(&planes[i]->gem);

	return ERR_PTR(err);
	}

	#ifdef CONFIG_DRM_FBDEV_EMULATION
	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 const struct fb_ops tegra_fb_ops = {
	.owner = THIS_MODULE,
	DRM_FB_HELPER_DEFAULT_OPS,
	.fb_fillrect = drm_fb_helper_sys_fillrect,
	.fb_copyarea = drm_fb_helper_sys_copyarea,
	.fb_imageblit = drm_fb_helper_sys_imageblit,
	.fb_mmap = tegra_fb_mmap,
	};

	static int tegra_fbdev_probe(struct drm_fb_helper *helper,
	struct drm_fb_helper_surface_size *sizes)
	{
	struct tegra_fbdev *fbdev = to_tegra_fbdev(helper);
	struct tegra_drm *tegra = helper->dev->dev_private;
	struct drm_device *drm = helper->dev;
	struct drm_mode_fb_cmd2 cmd = { 0 };
	unsigned int bytes_per_pixel;
	struct drm_framebuffer *fb;
	unsigned long offset;
	struct fb_info *info;
	struct tegra_bo *bo;
	size_t size;
	int err;

	bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);

	cmd.width = sizes->surface_width;
	cmd.height = sizes->surface_height;
	cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
	tegra->pitch_align);

	cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
	sizes->surface_depth);

	size = cmd.pitches[0] * cmd.height;

	bo = tegra_bo_create(drm, size, 0);
	if (IS_ERR(bo))
	return PTR_ERR(bo);

	info = drm_fb_helper_alloc_fbi(helper);
	if (IS_ERR(info)) {
	dev_err(drm->dev, "failed to allocate framebuffer info\n");
	drm_gem_object_put(&bo->gem);
	return PTR_ERR(info);
	}

	fbdev->fb = tegra_fb_alloc(drm, &cmd, &bo, 1);
	if (IS_ERR(fbdev->fb)) {
	err = PTR_ERR(fbdev->fb);
	dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
	err);
	drm_gem_object_put(&bo->gem);
	return PTR_ERR(fbdev->fb);
	}

	fb = fbdev->fb;
	helper->fb = fb;
	helper->fbdev = info;

	info->fbops = &tegra_fb_ops;

	drm_fb_helper_fill_info(info, helper, sizes);

	offset = info->var.xoffset * bytes_per_pixel +
	info->var.yoffset * fb->pitches[0];

	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 destroy;
	}
	}

	drm->mode_config.fb_base = (resource_size_t)bo->iova;
	info->screen_base = (void __iomem *)bo->vaddr + offset;
	info->screen_size = size;
	info->fix.smem_start = (unsigned long)(bo->iova + offset);
	info->fix.smem_len = size;

	return 0;

	destroy:
	drm_framebuffer_remove(fb);
	return err;
	}

	static const struct drm_fb_helper_funcs tegra_fb_helper_funcs = {
	.fb_probe = tegra_fbdev_probe,
	};

	static struct tegra_fbdev tegra_fbdev_create(struct drm_device drm)
	{
	struct tegra_fbdev *fbdev;

	fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
	if (!fbdev) {
	dev_err(drm->dev, "failed to allocate DRM fbdev\n");
	return ERR_PTR(-ENOMEM);
	}

	drm_fb_helper_prepare(drm, &fbdev->base, &tegra_fb_helper_funcs);

	return fbdev;
	}

	static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
	{
	kfree(fbdev);
	}

	static int tegra_fbdev_init(struct tegra_fbdev *fbdev,
	unsigned int preferred_bpp,
	unsigned int num_crtc,
	unsigned int max_connectors)
	{
	struct drm_device *drm = fbdev->base.dev;
	int err;

	err = drm_fb_helper_init(drm, &fbdev->base);
	if (err < 0) {
	dev_err(drm->dev, "failed to initialize DRM FB helper: %d\n",
	err);
	return err;
	}

	err = drm_fb_helper_initial_config(&fbdev->base, preferred_bpp);
	if (err < 0) {
	dev_err(drm->dev, "failed to set initial configuration: %d\n",
	err);
	goto fini;
	}

	return 0;

	fini:
	drm_fb_helper_fini(&fbdev->base);
	return err;
	}

	static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
	{
	drm_fb_helper_unregister_fbi(&fbdev->base);

	if (fbdev->fb) {
	struct tegra_bo *bo = tegra_fb_get_plane(fbdev->fb, 0);

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

	drm_framebuffer_remove(fbdev->fb);
	}

	drm_fb_helper_fini(&fbdev->base);
	tegra_fbdev_free(fbdev);
	}
	#endif

	int tegra_drm_fb_prepare(struct drm_device *drm)
	{
	#ifdef CONFIG_DRM_FBDEV_EMULATION
	struct tegra_drm *tegra = drm->dev_private;

	tegra->fbdev = tegra_fbdev_create(drm);
	if (IS_ERR(tegra->fbdev))
	return PTR_ERR(tegra->fbdev);
	#endif

	return 0;
	}

	void tegra_drm_fb_free(struct drm_device *drm)
	{
	#ifdef CONFIG_DRM_FBDEV_EMULATION
	struct tegra_drm *tegra = drm->dev_private;

	tegra_fbdev_free(tegra->fbdev);
	#endif
	}

	int tegra_drm_fb_init(struct drm_device *drm)
	{
	#ifdef CONFIG_DRM_FBDEV_EMULATION
	struct tegra_drm *tegra = drm->dev_private;
	int err;

	err = tegra_fbdev_init(tegra->fbdev, 32, drm->mode_config.num_crtc,
	drm->mode_config.num_connector);
	if (err < 0)
	return err;
	#endif

	return 0;
	}

	void tegra_drm_fb_exit(struct drm_device *drm)
	{
	#ifdef CONFIG_DRM_FBDEV_EMULATION
	struct tegra_drm *tegra = drm->dev_private;

	tegra_fbdev_exit(tegra->fbdev);
	#endif
	}