/*
   * Framebuffer driver for EFI/UEFI based system
   *
   * (c) 2006 Edgar Hucek <gimli@dark-green.com>
   * Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
   *
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/fb.h>
  #include <linux/platform_device.h>
  #include <linux/screen_info.h>

  #include <linux/dmi.h>

  #include <linux/pci.h>

  #include <video/vga.h>

  #include <asm/sysfb.h>

  static bool request_mem_succeeded = false;

  static struct pci_dev *default_vga;

  static struct fb_var_screeninfo efifb_defined = {

  	.activate		= FB_ACTIVATE_NOW,
  	.height			= -1,
  	.width			= -1,
  	.right_margin		= 32,
  	.upper_margin		= 16,
  	.lower_margin		= 4,
  	.vsync_len		= 4,
  	.vmode			= FB_VMODE_NONINTERLACED,
  };

  static struct fb_fix_screeninfo efifb_fix = {

  	.id			= "EFI VGA",
  	.type			= FB_TYPE_PACKED_PIXELS,
  	.accel			= FB_ACCEL_NONE,
  	.visual			= FB_VISUAL_TRUECOLOR,
  };
  
  static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
  			   unsigned blue, unsigned transp,
  			   struct fb_info *info)
  {
  	/*
  	 *  Set a single color register. The values supplied are
  	 *  already rounded down to the hardware's capabilities
  	 *  (according to the entries in the `var' structure). Return
  	 *  != 0 for invalid regno.
  	 */
  
  	if (regno >= info->cmap.len)
  		return 1;
  
  	if (regno < 16) {
  		red   >>= 8;
  		green >>= 8;
  		blue  >>= 8;
  		((u32 *)(info->pseudo_palette))[regno] =
  			(red   << info->var.red.offset)   |
  			(green << info->var.green.offset) |
  			(blue  << info->var.blue.offset);
  	}
  	return 0;
  }

  static void efifb_destroy(struct fb_info *info)
  {
  	if (info->screen_base)
  		iounmap(info->screen_base);

  	if (request_mem_succeeded)
  		release_mem_region(info->apertures->ranges[0].base,
  				   info->apertures->ranges[0].size);

  	fb_dealloc_cmap(&info->cmap);

  	framebuffer_release(info);
  }

  static struct fb_ops efifb_ops = {
  	.owner		= THIS_MODULE,

  	.fb_destroy	= efifb_destroy,

  	.fb_setcolreg	= efifb_setcolreg,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };

  struct pci_dev *vga_default_device(void)
  {
  	return default_vga;
  }

  EXPORT_SYMBOL_GPL(vga_default_device);

  void vga_set_default_device(struct pci_dev *pdev)
  {
  	default_vga = pdev;
  }

  static int efifb_setup(char *options)

  {
  	char *this_opt;
  	int i;

  	struct pci_dev *dev = NULL;

  	if (options && *options) {
  		while ((this_opt = strsep(&options, ",")) != NULL) {
  			if (!*this_opt) continue;

  			for (i = 0; i < M_UNKNOWN; i++) {

  				if (efifb_dmi_list[i].base != 0 &&
  				    !strcmp(this_opt, efifb_dmi_list[i].optname)) {

  					screen_info.lfb_base = efifb_dmi_list[i].base;
  					screen_info.lfb_linelength = efifb_dmi_list[i].stride;
  					screen_info.lfb_width = efifb_dmi_list[i].width;
  					screen_info.lfb_height = efifb_dmi_list[i].height;

  				}

  			}

  			if (!strncmp(this_opt, "base:", 5))
  				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
  			else if (!strncmp(this_opt, "stride:", 7))
  				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
  			else if (!strncmp(this_opt, "height:", 7))
  				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
  			else if (!strncmp(this_opt, "width:", 6))
  				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);

  		}

  	}

  
  	for_each_pci_dev(dev) {
  		int i;
  
  		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
  			continue;
  
  		for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
  			resource_size_t start, end;
  
  			if (!(pci_resource_flags(dev, i) & IORESOURCE_MEM))
  				continue;
  
  			start = pci_resource_start(dev, i);
  			end  = pci_resource_end(dev, i);
  
  			if (!start || !end)
  				continue;
  
  			if (screen_info.lfb_base >= start &&
  			    (screen_info.lfb_base + screen_info.lfb_size) < end)
  				default_vga = dev;
  		}
  	}

  	return 0;
  }

  static int efifb_probe(struct platform_device *dev)

  {
  	struct fb_info *info;
  	int err;
  	unsigned int size_vmode;
  	unsigned int size_remap;
  	unsigned int size_total;

  	char *option = NULL;
  
  	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
  		return -ENODEV;
  
  	if (fb_get_options("efifb", &option))
  		return -ENODEV;
  	efifb_setup(option);
  
  	/* We don't get linelength from UGA Draw Protocol, only from
  	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
  	 * passed in from the user, we really can't use the framebuffer.
  	 */
  	if (!screen_info.lfb_linelength)
  		return -ENODEV;

  	if (!screen_info.lfb_depth)
  		screen_info.lfb_depth = 32;
  	if (!screen_info.pages)
  		screen_info.pages = 1;

  	if (!screen_info.lfb_base) {
  		printk(KERN_DEBUG "efifb: invalid framebuffer address
  ");
  		return -ENODEV;
  	}
  	printk(KERN_INFO "efifb: probing for efifb
  ");

  
  	/* just assume they're all unset if any are */
  	if (!screen_info.blue_size) {
  		screen_info.blue_size = 8;
  		screen_info.blue_pos = 0;
  		screen_info.green_size = 8;
  		screen_info.green_pos = 8;
  		screen_info.red_size = 8;
  		screen_info.red_pos = 16;
  		screen_info.rsvd_size = 8;
  		screen_info.rsvd_pos = 24;
  	}

  
  	efifb_fix.smem_start = screen_info.lfb_base;
  	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
  	efifb_defined.xres = screen_info.lfb_width;
  	efifb_defined.yres = screen_info.lfb_height;
  	efifb_fix.line_length = screen_info.lfb_linelength;
  
  	/*   size_vmode -- that is the amount of memory needed for the
  	 *                 used video mode, i.e. the minimum amount of
  	 *                 memory we need. */
  	size_vmode = efifb_defined.yres * efifb_fix.line_length;
  
  	/*   size_total -- all video memory we have. Used for
  	 *                 entries, ressource allocation and bounds
  	 *                 checking. */
  	size_total = screen_info.lfb_size;
  	if (size_total < size_vmode)
  		size_total = size_vmode;
  
  	/*   size_remap -- the amount of video memory we are going to
  	 *                 use for efifb.  With modern cards it is no
  	 *                 option to simply use size_total as that
  	 *                 wastes plenty of kernel address space. */
  	size_remap  = size_vmode * 2;

  	if (size_remap > size_total)
  		size_remap = size_total;

  	if (size_remap % PAGE_SIZE)
  		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);

  	efifb_fix.smem_len = size_remap;

  	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {

  		request_mem_succeeded = true;

  	} else {

  		/* We cannot make this fatal. Sometimes this comes from magic
  		   spaces our resource handlers simply don't know about */
  		printk(KERN_WARNING
  		       "efifb: cannot reserve video memory at 0x%lx
  ",
  			efifb_fix.smem_start);

  	}

  
  	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
  	if (!info) {

  		printk(KERN_ERR "efifb: cannot allocate framebuffer
  ");

  		err = -ENOMEM;
  		goto err_release_mem;
  	}
  	info->pseudo_palette = info->par;
  	info->par = NULL;

  	info->apertures = alloc_apertures(1);
  	if (!info->apertures) {
  		err = -ENOMEM;
  		goto err_release_fb;
  	}
  	info->apertures->ranges[0].base = efifb_fix.smem_start;
  	info->apertures->ranges[0].size = size_remap;

  	info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);

  	if (!info->screen_base) {
  		printk(KERN_ERR "efifb: abort, cannot ioremap video memory "
  				"0x%x @ 0x%lx
  ",
  			efifb_fix.smem_len, efifb_fix.smem_start);
  		err = -EIO;

  		goto err_release_fb;

  	}
  
  	printk(KERN_INFO "efifb: framebuffer at 0x%lx, mapped to 0x%p, "
  	       "using %dk, total %dk
  ",
  	       efifb_fix.smem_start, info->screen_base,
  	       size_remap/1024, size_total/1024);
  	printk(KERN_INFO "efifb: mode is %dx%dx%d, linelength=%d, pages=%d
  ",
  	       efifb_defined.xres, efifb_defined.yres,
  	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
  	       screen_info.pages);
  
  	efifb_defined.xres_virtual = efifb_defined.xres;
  	efifb_defined.yres_virtual = efifb_fix.smem_len /
  					efifb_fix.line_length;
  	printk(KERN_INFO "efifb: scrolling: redraw
  ");
  	efifb_defined.yres_virtual = efifb_defined.yres;
  
  	/* some dummy values for timing to make fbset happy */
  	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
  					1000 / efifb_defined.yres;
  	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
  	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
  
  	efifb_defined.red.offset    = screen_info.red_pos;
  	efifb_defined.red.length    = screen_info.red_size;
  	efifb_defined.green.offset  = screen_info.green_pos;
  	efifb_defined.green.length  = screen_info.green_size;
  	efifb_defined.blue.offset   = screen_info.blue_pos;
  	efifb_defined.blue.length   = screen_info.blue_size;
  	efifb_defined.transp.offset = screen_info.rsvd_pos;
  	efifb_defined.transp.length = screen_info.rsvd_size;
  
  	printk(KERN_INFO "efifb: %s: "
  	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d
  ",
  	       "Truecolor",
  	       screen_info.rsvd_size,
  	       screen_info.red_size,
  	       screen_info.green_size,
  	       screen_info.blue_size,
  	       screen_info.rsvd_pos,
  	       screen_info.red_pos,
  	       screen_info.green_pos,
  	       screen_info.blue_pos);
  
  	efifb_fix.ypanstep  = 0;
  	efifb_fix.ywrapstep = 0;
  
  	info->fbops = &efifb_ops;
  	info->var = efifb_defined;
  	info->fix = efifb_fix;

  	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;

  	if ((err = fb_alloc_cmap(&info->cmap, 256, 0)) < 0) {
  		printk(KERN_ERR "efifb: cannot allocate colormap
  ");

  		goto err_unmap;
  	}

  	if ((err = register_framebuffer(info)) < 0) {
  		printk(KERN_ERR "efifb: cannot register framebuffer
  ");

  		goto err_fb_dealoc;
  	}

  	fb_info(info, "%s frame buffer device
  ", info->fix.id);

  	return 0;
  
  err_fb_dealoc:
  	fb_dealloc_cmap(&info->cmap);
  err_unmap:
  	iounmap(info->screen_base);

  err_release_fb:

  	framebuffer_release(info);
  err_release_mem:

  	if (request_mem_succeeded)

  		release_mem_region(efifb_fix.smem_start, size_total);

  	return err;
  }
  
  static struct platform_driver efifb_driver = {

  	.driver = {
  		.name = "efi-framebuffer",
  		.owner = THIS_MODULE,

  	},

  	.probe = efifb_probe,

  };

  module_platform_driver(efifb_driver);

  MODULE_LICENSE("GPL");