drivers/gpu/drm/exynos/exynos_drm_fbdev.c - arm/linux - Git at Google

 /* exynos_drm_fbdev.c
  *
  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
  * Authors:
  *	Inki Dae <inki.dae@samsung.com>
  *	Joonyoung Shim <jy0922.shim@samsung.com>
  *	Seung-Woo Kim <sw0312.kim@samsung.com>
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
  */

 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/exynos_drm.h>

 #include "exynos_drm_drv.h"
 #include "exynos_drm_fb.h"
 #include "exynos_drm_fbdev.h"
 #include "exynos_drm_gem.h"
 #include "exynos_drm_iommu.h"

 #define MAX_CONNECTOR		4
 #define PREFERRED_BPP		32

 #define to_exynos_fbdev(x)	container_of(x, struct exynos_drm_fbdev,\
 				drm_fb_helper)

 struct exynos_drm_fbdev {
 	struct drm_fb_helper		drm_fb_helper;
 	struct exynos_drm_gem_obj	*exynos_gem_obj;
 };

 static int exynos_drm_fb_mmap(struct fb_info *info,
 			struct vm_area_struct *vma)
 {
 	struct drm_fb_helper *helper = info->par;
 	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper);
 	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
 	struct exynos_drm_gem_buf *buffer = exynos_gem_obj->buffer;
 	unsigned long vm_size;
 	int ret;

 	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;

 	vm_size = vma->vm_end - vma->vm_start;

 	if (vm_size > buffer->size)
 		return -EINVAL;

 	ret = dma_mmap_attrs(helper->dev->dev, vma, buffer->pages,
 		buffer->dma_addr, buffer->size, &buffer->dma_attrs);
 	if (ret < 0) {
 		DRM_ERROR("failed to mmap.\n");
 		return ret;
 	}

 	return 0;
 }

 static struct fb_ops exynos_drm_fb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_mmap        = exynos_drm_fb_mmap,
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
 	.fb_check_var	= drm_fb_helper_check_var,
 	.fb_set_par	= drm_fb_helper_set_par,
 	.fb_blank	= drm_fb_helper_blank,
 	.fb_pan_display	= drm_fb_helper_pan_display,
 	.fb_setcmap	= drm_fb_helper_setcmap,
 };

 static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
 				     struct drm_framebuffer *fb)
 {
 	struct fb_info *fbi = helper->fbdev;
 	struct drm_device *dev = helper->dev;
 	struct exynos_drm_gem_buf *buffer;
 	unsigned int size = fb->width * fb->height * (fb->bits_per_pixel >> 3);
 	unsigned long offset;

 	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
 	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);

 	/* RGB formats use only one buffer */
 	buffer = exynos_drm_fb_buffer(fb, 0);
 	if (!buffer) {
 		DRM_DEBUG_KMS("buffer is null.\n");
 		return -EFAULT;
 	}

 	/* map pages with kernel virtual space. */
 	if (!buffer->kvaddr) {
 		if (is_drm_iommu_supported(dev)) {
 			unsigned int nr_pages = buffer->size >> PAGE_SHIFT;

 			buffer->kvaddr = (void __iomem *) vmap(buffer->pages,
 					nr_pages, VM_MAP,
 					pgprot_writecombine(PAGE_KERNEL));
 		} else {
 			phys_addr_t dma_addr = buffer->dma_addr;
 			if (dma_addr)
 				buffer->kvaddr = (void __iomem *)phys_to_virt(dma_addr);
 			else
 				buffer->kvaddr = (void __iomem *)NULL;
 		}
 		if (!buffer->kvaddr) {
 			DRM_ERROR("failed to map pages to kernel space.\n");
 			return -EIO;
 		}
 	}

 	/* buffer count to framebuffer always is 1 at booting time. */
 	exynos_drm_fb_set_buf_cnt(fb, 1);

 	offset = fbi->var.xoffset * (fb->bits_per_pixel >> 3);
 	offset += fbi->var.yoffset * fb->pitches[0];

 	fbi->screen_base = buffer->kvaddr + offset;
 	fbi->screen_size = size;

 	return 0;
 }

 static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
 				    struct drm_fb_helper_surface_size *sizes)
 {
 	struct exynos_drm_fbdev *exynos_fbdev = to_exynos_fbdev(helper);
 	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct drm_device *dev = helper->dev;
 	struct fb_info *fbi;
 	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
 	struct platform_device *pdev = dev->platformdev;
 	unsigned long size;
 	int ret;

 	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d\n",
 			sizes->surface_width, sizes->surface_height,
 			sizes->surface_bpp);

 	mode_cmd.width = sizes->surface_width;
 	mode_cmd.height = sizes->surface_height;
 	mode_cmd.pitches[0] = sizes->surface_width * (sizes->surface_bpp >> 3);
 	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
 							  sizes->surface_depth);

 	mutex_lock(&dev->struct_mutex);

 	fbi = framebuffer_alloc(0, &pdev->dev);
 	if (!fbi) {
 		DRM_ERROR("failed to allocate fb info.\n");
 		ret = -ENOMEM;
 		goto out;
 	}

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

 	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG, size);
 	/*
 	 * If physically contiguous memory allocation fails and if IOMMU is
 	 * supported then try to get buffer from non physically contiguous
 	 * memory area.
 	 */
 	if (IS_ERR(exynos_gem_obj) && is_drm_iommu_supported(dev)) {
 		dev_warn(&pdev->dev, "contiguous FB allocation failed, falling back to non-contiguous\n");
 		exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_NONCONTIG,
 							size);
 	}

 	if (IS_ERR(exynos_gem_obj)) {
 		ret = PTR_ERR(exynos_gem_obj);
 		goto err_release_framebuffer;
 	}

 	exynos_fbdev->exynos_gem_obj = exynos_gem_obj;

 	helper->fb = exynos_drm_framebuffer_init(dev, &mode_cmd,
 			&exynos_gem_obj->base);
 	if (IS_ERR(helper->fb)) {
 		DRM_ERROR("failed to create drm framebuffer.\n");
 		ret = PTR_ERR(helper->fb);
 		goto err_destroy_gem;
 	}

 	helper->fbdev = fbi;

 	fbi->par = helper;
 	fbi->flags = FBINFO_FLAG_DEFAULT;
 	fbi->fbops = &exynos_drm_fb_ops;

 	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
 	if (ret) {
 		DRM_ERROR("failed to allocate cmap.\n");
 		goto err_destroy_framebuffer;
 	}

 	ret = exynos_drm_fbdev_update(helper, helper->fb);
 	if (ret < 0)
 		goto err_dealloc_cmap;

 	mutex_unlock(&dev->struct_mutex);
 	return ret;

 err_dealloc_cmap:
 	fb_dealloc_cmap(&fbi->cmap);
 err_destroy_framebuffer:
 	drm_framebuffer_cleanup(helper->fb);
 err_destroy_gem:
 	exynos_drm_gem_destroy(exynos_gem_obj);
 err_release_framebuffer:
 	framebuffer_release(fbi);

 /*
  * if failed, all resources allocated above would be released by
  * drm_mode_config_cleanup() when drm_load() had been called prior
  * to any specific driver such as fimd or hdmi driver.
  */
 out:
 	mutex_unlock(&dev->struct_mutex);
 	return ret;
 }

 static struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
 	.fb_probe =	exynos_drm_fbdev_create,
 };

 static bool exynos_drm_fbdev_is_anything_connected(struct drm_device *dev)
 {
 	struct drm_connector *connector;
 	bool ret = false;

 	mutex_lock(&dev->mode_config.mutex);
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		if (connector->status != connector_status_connected)
 			continue;

 		ret = true;
 		break;
 	}
 	mutex_unlock(&dev->mode_config.mutex);

 	return ret;
 }

 int exynos_drm_fbdev_init(struct drm_device *dev)
 {
 	struct exynos_drm_fbdev *fbdev;
 	struct exynos_drm_private *private = dev->dev_private;
 	struct drm_fb_helper *helper;
 	unsigned int num_crtc;
 	int ret;

 	if (!dev->mode_config.num_crtc || !dev->mode_config.num_connector)
 		return 0;

 	if (!exynos_drm_fbdev_is_anything_connected(dev))
 		return 0;

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

 	private->fb_helper = helper = &fbdev->drm_fb_helper;
 	helper->funcs = &exynos_drm_fb_helper_funcs;

 	num_crtc = dev->mode_config.num_crtc;

 	ret = drm_fb_helper_init(dev, helper, num_crtc, MAX_CONNECTOR);
 	if (ret < 0) {
 		DRM_ERROR("failed to initialize drm fb helper.\n");
 		goto err_init;
 	}

 	ret = drm_fb_helper_single_add_all_connectors(helper);
 	if (ret < 0) {
 		DRM_ERROR("failed to register drm_fb_helper_connector.\n");
 		goto err_setup;

 	}

 	/* disable all the possible outputs/crtcs before entering KMS mode */
 	drm_helper_disable_unused_functions(dev);

 	ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP);
 	if (ret < 0) {
 		DRM_ERROR("failed to set up hw configuration.\n");
 		goto err_setup;
 	}

 	return 0;

 err_setup:
 	drm_fb_helper_fini(helper);

 err_init:
 	private->fb_helper = NULL;
 	kfree(fbdev);

 	return ret;
 }

 static void exynos_drm_fbdev_destroy(struct drm_device *dev,
 				      struct drm_fb_helper *fb_helper)
 {
 	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(fb_helper);
 	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
 	struct drm_framebuffer *fb;

 	if (is_drm_iommu_supported(dev) && exynos_gem_obj->buffer->kvaddr)
 		vunmap(exynos_gem_obj->buffer->kvaddr);

 	/* release drm framebuffer and real buffer */
 	if (fb_helper->fb && fb_helper->fb->funcs) {
 		fb = fb_helper->fb;
 		if (fb) {
 			drm_framebuffer_unregister_private(fb);
 			drm_framebuffer_remove(fb);
 		}
 	}

 	/* release linux framebuffer */
 	if (fb_helper->fbdev) {
 		struct fb_info *info;
 		int ret;

 		info = fb_helper->fbdev;
 		ret = unregister_framebuffer(info);
 		if (ret < 0)
 			DRM_DEBUG_KMS("failed unregister_framebuffer()\n");

 		if (info->cmap.len)
 			fb_dealloc_cmap(&info->cmap);

 		framebuffer_release(info);
 	}

 	drm_fb_helper_fini(fb_helper);
 }

 void exynos_drm_fbdev_fini(struct drm_device *dev)
 {
 	struct exynos_drm_private *private = dev->dev_private;
 	struct exynos_drm_fbdev *fbdev;

 	if (!private || !private->fb_helper)
 		return;

 	fbdev = to_exynos_fbdev(private->fb_helper);

 	if (fbdev->exynos_gem_obj)
 		exynos_drm_gem_destroy(fbdev->exynos_gem_obj);

 	exynos_drm_fbdev_destroy(dev, private->fb_helper);
 	kfree(fbdev);
 	private->fb_helper = NULL;
 }

 void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
 {
 	struct exynos_drm_private *private = dev->dev_private;

 	if (!private || !private->fb_helper)
 		return;

 	drm_fb_helper_restore_fbdev_mode_unlocked(private->fb_helper);
 }
	/* exynos_drm_fbdev.c
	*
	* Copyright (c) 2011 Samsung Electronics Co., Ltd.
	* Authors:
	* Inki Dae <inki.dae@samsung.com>
	* Joonyoung Shim <jy0922.shim@samsung.com>
	* Seung-Woo Kim <sw0312.kim@samsung.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <drm/drmP.h>
	#include <drm/drm_crtc.h>
	#include <drm/drm_fb_helper.h>
	#include <drm/drm_crtc_helper.h>
	#include <drm/exynos_drm.h>

	#include "exynos_drm_drv.h"
	#include "exynos_drm_fb.h"
	#include "exynos_drm_fbdev.h"
	#include "exynos_drm_gem.h"
	#include "exynos_drm_iommu.h"

	#define MAX_CONNECTOR 4
	#define PREFERRED_BPP 32

	#define to_exynos_fbdev(x) container_of(x, struct exynos_drm_fbdev,\
	drm_fb_helper)

	struct exynos_drm_fbdev {
	struct drm_fb_helper drm_fb_helper;
	struct exynos_drm_gem_obj *exynos_gem_obj;
	};

	static int exynos_drm_fb_mmap(struct fb_info *info,
	struct vm_area_struct *vma)
	{
	struct drm_fb_helper *helper = info->par;
	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper);
	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
	struct exynos_drm_gem_buf *buffer = exynos_gem_obj->buffer;
	unsigned long vm_size;
	int ret;

	vma->vm_flags \|= VM_IO \| VM_DONTEXPAND \| VM_DONTDUMP;

	vm_size = vma->vm_end - vma->vm_start;

	if (vm_size > buffer->size)
	return -EINVAL;

	ret = dma_mmap_attrs(helper->dev->dev, vma, buffer->pages,
	buffer->dma_addr, buffer->size, &buffer->dma_attrs);
	if (ret < 0) {
	DRM_ERROR("failed to mmap.\n");
	return ret;
	}

	return 0;
	}

	static struct fb_ops exynos_drm_fb_ops = {
	.owner = THIS_MODULE,
	.fb_mmap = exynos_drm_fb_mmap,
	.fb_fillrect = cfb_fillrect,
	.fb_copyarea = cfb_copyarea,
	.fb_imageblit = cfb_imageblit,
	.fb_check_var = drm_fb_helper_check_var,
	.fb_set_par = drm_fb_helper_set_par,
	.fb_blank = drm_fb_helper_blank,
	.fb_pan_display = drm_fb_helper_pan_display,
	.fb_setcmap = drm_fb_helper_setcmap,
	};

	static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
	struct drm_framebuffer *fb)
	{
	struct fb_info *fbi = helper->fbdev;
	struct drm_device *dev = helper->dev;
	struct exynos_drm_gem_buf *buffer;
	unsigned int size = fb->width * fb->height * (fb->bits_per_pixel >> 3);
	unsigned long offset;

	drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
	drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);

	/* RGB formats use only one buffer */
	buffer = exynos_drm_fb_buffer(fb, 0);
	if (!buffer) {
	DRM_DEBUG_KMS("buffer is null.\n");
	return -EFAULT;
	}

	/* map pages with kernel virtual space. */
	if (!buffer->kvaddr) {
	if (is_drm_iommu_supported(dev)) {
	unsigned int nr_pages = buffer->size >> PAGE_SHIFT;

	buffer->kvaddr = (void __iomem *) vmap(buffer->pages,
	nr_pages, VM_MAP,
	pgprot_writecombine(PAGE_KERNEL));
	} else {
	phys_addr_t dma_addr = buffer->dma_addr;
	if (dma_addr)
	buffer->kvaddr = (void __iomem *)phys_to_virt(dma_addr);
	else
	buffer->kvaddr = (void __iomem *)NULL;
	}
	if (!buffer->kvaddr) {
	DRM_ERROR("failed to map pages to kernel space.\n");
	return -EIO;
	}
	}

	/* buffer count to framebuffer always is 1 at booting time. */
	exynos_drm_fb_set_buf_cnt(fb, 1);

	offset = fbi->var.xoffset * (fb->bits_per_pixel >> 3);
	offset += fbi->var.yoffset * fb->pitches[0];

	fbi->screen_base = buffer->kvaddr + offset;
	fbi->screen_size = size;

	return 0;
	}

	static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
	struct drm_fb_helper_surface_size *sizes)
	{
	struct exynos_drm_fbdev *exynos_fbdev = to_exynos_fbdev(helper);
	struct exynos_drm_gem_obj *exynos_gem_obj;
	struct drm_device *dev = helper->dev;
	struct fb_info *fbi;
	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
	struct platform_device *pdev = dev->platformdev;
	unsigned long size;
	int ret;

	DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d\n",
	sizes->surface_width, sizes->surface_height,
	sizes->surface_bpp);

	mode_cmd.width = sizes->surface_width;
	mode_cmd.height = sizes->surface_height;
	mode_cmd.pitches[0] = sizes->surface_width * (sizes->surface_bpp >> 3);
	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
	sizes->surface_depth);

	mutex_lock(&dev->struct_mutex);

	fbi = framebuffer_alloc(0, &pdev->dev);
	if (!fbi) {
	DRM_ERROR("failed to allocate fb info.\n");
	ret = -ENOMEM;
	goto out;
	}

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

	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_CONTIG, size);
	/*
	* If physically contiguous memory allocation fails and if IOMMU is
	* supported then try to get buffer from non physically contiguous
	* memory area.
	*/
	if (IS_ERR(exynos_gem_obj) && is_drm_iommu_supported(dev)) {
	dev_warn(&pdev->dev, "contiguous FB allocation failed, falling back to non-contiguous\n");
	exynos_gem_obj = exynos_drm_gem_create(dev, EXYNOS_BO_NONCONTIG,
	size);
	}

	if (IS_ERR(exynos_gem_obj)) {
	ret = PTR_ERR(exynos_gem_obj);
	goto err_release_framebuffer;
	}

	exynos_fbdev->exynos_gem_obj = exynos_gem_obj;

	helper->fb = exynos_drm_framebuffer_init(dev, &mode_cmd,
	&exynos_gem_obj->base);
	if (IS_ERR(helper->fb)) {
	DRM_ERROR("failed to create drm framebuffer.\n");
	ret = PTR_ERR(helper->fb);
	goto err_destroy_gem;
	}

	helper->fbdev = fbi;

	fbi->par = helper;
	fbi->flags = FBINFO_FLAG_DEFAULT;
	fbi->fbops = &exynos_drm_fb_ops;

	ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
	if (ret) {
	DRM_ERROR("failed to allocate cmap.\n");
	goto err_destroy_framebuffer;
	}

	ret = exynos_drm_fbdev_update(helper, helper->fb);
	if (ret < 0)
	goto err_dealloc_cmap;

	mutex_unlock(&dev->struct_mutex);
	return ret;

	err_dealloc_cmap:
	fb_dealloc_cmap(&fbi->cmap);
	err_destroy_framebuffer:
	drm_framebuffer_cleanup(helper->fb);
	err_destroy_gem:
	exynos_drm_gem_destroy(exynos_gem_obj);
	err_release_framebuffer:
	framebuffer_release(fbi);

	/*
	* if failed, all resources allocated above would be released by
	* drm_mode_config_cleanup() when drm_load() had been called prior
	* to any specific driver such as fimd or hdmi driver.
	*/
	out:
	mutex_unlock(&dev->struct_mutex);
	return ret;
	}

	static struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
	.fb_probe = exynos_drm_fbdev_create,
	};

	static bool exynos_drm_fbdev_is_anything_connected(struct drm_device *dev)
	{
	struct drm_connector *connector;
	bool ret = false;

	mutex_lock(&dev->mode_config.mutex);
	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
	if (connector->status != connector_status_connected)
	continue;

	ret = true;
	break;
	}
	mutex_unlock(&dev->mode_config.mutex);

	return ret;
	}

	int exynos_drm_fbdev_init(struct drm_device *dev)
	{
	struct exynos_drm_fbdev *fbdev;
	struct exynos_drm_private *private = dev->dev_private;
	struct drm_fb_helper *helper;
	unsigned int num_crtc;
	int ret;

	if (!dev->mode_config.num_crtc \|\| !dev->mode_config.num_connector)
	return 0;

	if (!exynos_drm_fbdev_is_anything_connected(dev))
	return 0;

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

	private->fb_helper = helper = &fbdev->drm_fb_helper;
	helper->funcs = &exynos_drm_fb_helper_funcs;

	num_crtc = dev->mode_config.num_crtc;

	ret = drm_fb_helper_init(dev, helper, num_crtc, MAX_CONNECTOR);
	if (ret < 0) {
	DRM_ERROR("failed to initialize drm fb helper.\n");
	goto err_init;
	}

	ret = drm_fb_helper_single_add_all_connectors(helper);
	if (ret < 0) {
	DRM_ERROR("failed to register drm_fb_helper_connector.\n");
	goto err_setup;

	}

	/* disable all the possible outputs/crtcs before entering KMS mode */
	drm_helper_disable_unused_functions(dev);

	ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP);
	if (ret < 0) {
	DRM_ERROR("failed to set up hw configuration.\n");
	goto err_setup;
	}

	return 0;

	err_setup:
	drm_fb_helper_fini(helper);

	err_init:
	private->fb_helper = NULL;
	kfree(fbdev);

	return ret;
	}

	static void exynos_drm_fbdev_destroy(struct drm_device *dev,
	struct drm_fb_helper *fb_helper)
	{
	struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(fb_helper);
	struct exynos_drm_gem_obj *exynos_gem_obj = exynos_fbd->exynos_gem_obj;
	struct drm_framebuffer *fb;

	if (is_drm_iommu_supported(dev) && exynos_gem_obj->buffer->kvaddr)
	vunmap(exynos_gem_obj->buffer->kvaddr);

	/* release drm framebuffer and real buffer */
	if (fb_helper->fb && fb_helper->fb->funcs) {
	fb = fb_helper->fb;
	if (fb) {
	drm_framebuffer_unregister_private(fb);
	drm_framebuffer_remove(fb);
	}
	}

	/* release linux framebuffer */
	if (fb_helper->fbdev) {
	struct fb_info *info;
	int ret;

	info = fb_helper->fbdev;
	ret = unregister_framebuffer(info);
	if (ret < 0)
	DRM_DEBUG_KMS("failed unregister_framebuffer()\n");

	if (info->cmap.len)
	fb_dealloc_cmap(&info->cmap);

	framebuffer_release(info);
	}

	drm_fb_helper_fini(fb_helper);
	}

	void exynos_drm_fbdev_fini(struct drm_device *dev)
	{
	struct exynos_drm_private *private = dev->dev_private;
	struct exynos_drm_fbdev *fbdev;

	if (!private \|\| !private->fb_helper)
	return;

	fbdev = to_exynos_fbdev(private->fb_helper);

	if (fbdev->exynos_gem_obj)
	exynos_drm_gem_destroy(fbdev->exynos_gem_obj);

	exynos_drm_fbdev_destroy(dev, private->fb_helper);
	kfree(fbdev);
	private->fb_helper = NULL;
	}

	void exynos_drm_fbdev_restore_mode(struct drm_device *dev)
	{
	struct exynos_drm_private *private = dev->dev_private;

	if (!private \|\| !private->fb_helper)
	return;

	drm_fb_helper_restore_fbdev_mode_unlocked(private->fb_helper);
	}