/*
   * linux/drivers/video/ep93xx-fb.c
   *
   * Framebuffer support for the EP93xx series.
   *
   * Copyright (C) 2007 Bluewater Systems Ltd
   * Author: Ryan Mallon
   *
   * Copyright (c) 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
   *
   * Based on the Cirrus Logic ep93xxfb driver, and various other ep93xxfb
   * drivers.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #include <linux/platform_device.h>
  #include <linux/module.h>
  #include <linux/dma-mapping.h>
  #include <linux/slab.h>
  #include <linux/clk.h>
  #include <linux/fb.h>
  #include <linux/io.h>
  
  #include <linux/platform_data/video-ep93xx.h>
  
  /* Vertical Frame Timing Registers */
  #define EP93XXFB_VLINES_TOTAL			0x0000	/* SW locked */
  #define EP93XXFB_VSYNC				0x0004	/* SW locked */
  #define EP93XXFB_VACTIVE			0x0008	/* SW locked */
  #define EP93XXFB_VBLANK				0x0228	/* SW locked */
  #define EP93XXFB_VCLK				0x000c	/* SW locked */
  
  /* Horizontal Frame Timing Registers */
  #define EP93XXFB_HCLKS_TOTAL			0x0010	/* SW locked */
  #define EP93XXFB_HSYNC				0x0014	/* SW locked */
  #define EP93XXFB_HACTIVE			0x0018	/* SW locked */
  #define EP93XXFB_HBLANK				0x022c	/* SW locked */
  #define EP93XXFB_HCLK				0x001c	/* SW locked */
  
  /* Frame Buffer Memory Configuration Registers */
  #define EP93XXFB_SCREEN_PAGE			0x0028
  #define EP93XXFB_SCREEN_HPAGE			0x002c
  #define EP93XXFB_SCREEN_LINES			0x0030
  #define EP93XXFB_LINE_LENGTH			0x0034
  #define EP93XXFB_VLINE_STEP			0x0038
  #define EP93XXFB_LINE_CARRY			0x003c	/* SW locked */
  #define EP93XXFB_EOL_OFFSET			0x0230
  
  /* Other Video Registers */
  #define EP93XXFB_BRIGHTNESS			0x0020
  #define EP93XXFB_ATTRIBS			0x0024	/* SW locked */
  #define EP93XXFB_SWLOCK				0x007c	/* SW locked */
  #define EP93XXFB_AC_RATE			0x0214
  #define EP93XXFB_FIFO_LEVEL			0x0234
  #define EP93XXFB_PIXELMODE			0x0054
  #define EP93XXFB_PIXELMODE_32BPP		(0x7 << 0)
  #define EP93XXFB_PIXELMODE_24BPP		(0x6 << 0)
  #define EP93XXFB_PIXELMODE_16BPP		(0x4 << 0)
  #define EP93XXFB_PIXELMODE_8BPP			(0x2 << 0)
  #define EP93XXFB_PIXELMODE_SHIFT_1P_24B		(0x0 << 3)
  #define EP93XXFB_PIXELMODE_SHIFT_1P_18B		(0x1 << 3)
  #define EP93XXFB_PIXELMODE_COLOR_LUT		(0x0 << 10)
  #define EP93XXFB_PIXELMODE_COLOR_888		(0x4 << 10)
  #define EP93XXFB_PIXELMODE_COLOR_555		(0x5 << 10)
  #define EP93XXFB_PARL_IF_OUT			0x0058
  #define EP93XXFB_PARL_IF_IN			0x005c
  
  /* Blink Control Registers */
  #define EP93XXFB_BLINK_RATE			0x0040
  #define EP93XXFB_BLINK_MASK			0x0044
  #define EP93XXFB_BLINK_PATTRN			0x0048
  #define EP93XXFB_PATTRN_MASK			0x004c
  #define EP93XXFB_BKGRND_OFFSET			0x0050
  
  /* Hardware Cursor Registers */
  #define EP93XXFB_CURSOR_ADR_START		0x0060
  #define EP93XXFB_CURSOR_ADR_RESET		0x0064
  #define EP93XXFB_CURSOR_SIZE			0x0068
  #define EP93XXFB_CURSOR_COLOR1			0x006c
  #define EP93XXFB_CURSOR_COLOR2			0x0070
  #define EP93XXFB_CURSOR_BLINK_COLOR1		0x021c
  #define EP93XXFB_CURSOR_BLINK_COLOR2		0x0220
  #define EP93XXFB_CURSOR_XY_LOC			0x0074
  #define EP93XXFB_CURSOR_DSCAN_HY_LOC		0x0078
  #define EP93XXFB_CURSOR_BLINK_RATE_CTRL		0x0224
  
  /* LUT Registers */
  #define EP93XXFB_GRY_SCL_LUTR			0x0080
  #define EP93XXFB_GRY_SCL_LUTG			0x0280
  #define EP93XXFB_GRY_SCL_LUTB			0x0300
  #define EP93XXFB_LUT_SW_CONTROL			0x0218
  #define EP93XXFB_LUT_SW_CONTROL_SWTCH		(1 << 0)
  #define EP93XXFB_LUT_SW_CONTROL_SSTAT		(1 << 1)
  #define EP93XXFB_COLOR_LUT			0x0400
  
  /* Video Signature Registers */
  #define EP93XXFB_VID_SIG_RSLT_VAL		0x0200
  #define EP93XXFB_VID_SIG_CTRL			0x0204
  #define EP93XXFB_VSIG				0x0208
  #define EP93XXFB_HSIG				0x020c
  #define EP93XXFB_SIG_CLR_STR			0x0210
  
  /* Minimum / Maximum resolutions supported */
  #define EP93XXFB_MIN_XRES			64
  #define EP93XXFB_MIN_YRES			64
  #define EP93XXFB_MAX_XRES			1024
  #define EP93XXFB_MAX_YRES			768
  
  struct ep93xx_fbi {
  	struct ep93xxfb_mach_info	*mach_info;
  	struct clk			*clk;
  	struct resource			*res;
  	void __iomem			*mmio_base;
  	unsigned int			pseudo_palette[256];
  };
  
  static int check_screenpage_bug = 1;
  module_param(check_screenpage_bug, int, 0644);
  MODULE_PARM_DESC(check_screenpage_bug,
  		 "Check for bit 27 screen page bug. Default = 1");
  
  static inline unsigned int ep93xxfb_readl(struct ep93xx_fbi *fbi,
  					  unsigned int off)
  {
  	return __raw_readl(fbi->mmio_base + off);
  }
  
  static inline void ep93xxfb_writel(struct ep93xx_fbi *fbi,
  				   unsigned int val, unsigned int off)
  {
  	__raw_writel(val, fbi->mmio_base + off);
  }
  
  /*
   * Write to one of the locked raster registers.
   */
  static inline void ep93xxfb_out_locked(struct ep93xx_fbi *fbi,
  				       unsigned int val, unsigned int reg)
  {
  	/*
  	 * We don't need a lock or delay here since the raster register
  	 * block will remain unlocked until the next access.
  	 */
  	ep93xxfb_writel(fbi, 0xaa, EP93XXFB_SWLOCK);
  	ep93xxfb_writel(fbi, val, reg);
  }
  
  static void ep93xxfb_set_video_attribs(struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	unsigned int attribs;
  
  	attribs = EP93XXFB_ENABLE;
  	attribs |= fbi->mach_info->flags;
  	ep93xxfb_out_locked(fbi, attribs, EP93XXFB_ATTRIBS);
  }
  
  static int ep93xxfb_set_pixelmode(struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	unsigned int val;
  
  	info->var.transp.offset = 0;
  	info->var.transp.length = 0;
  
  	switch (info->var.bits_per_pixel) {
  	case 8:
  		val = EP93XXFB_PIXELMODE_8BPP | EP93XXFB_PIXELMODE_COLOR_LUT |
  			EP93XXFB_PIXELMODE_SHIFT_1P_18B;
  
  		info->var.red.offset	= 0;
  		info->var.red.length	= 8;
  		info->var.green.offset	= 0;
  		info->var.green.length	= 8;
  		info->var.blue.offset	= 0;
  		info->var.blue.length	= 8;
  		info->fix.visual 	= FB_VISUAL_PSEUDOCOLOR;
  		break;
  
  	case 16:
  		val = EP93XXFB_PIXELMODE_16BPP | EP93XXFB_PIXELMODE_COLOR_555 |
  			EP93XXFB_PIXELMODE_SHIFT_1P_18B;
  
  		info->var.red.offset	= 11;
  		info->var.red.length	= 5;
  		info->var.green.offset	= 5;
  		info->var.green.length	= 6;
  		info->var.blue.offset	= 0;
  		info->var.blue.length	= 5;
  		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
  		break;
  
  	case 24:
  		val = EP93XXFB_PIXELMODE_24BPP | EP93XXFB_PIXELMODE_COLOR_888 |
  			EP93XXFB_PIXELMODE_SHIFT_1P_24B;
  
  		info->var.red.offset	= 16;
  		info->var.red.length	= 8;
  		info->var.green.offset	= 8;
  		info->var.green.length	= 8;
  		info->var.blue.offset	= 0;
  		info->var.blue.length	= 8;
  		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
  		break;
  
  	case 32:
  		val = EP93XXFB_PIXELMODE_32BPP | EP93XXFB_PIXELMODE_COLOR_888 |
  			EP93XXFB_PIXELMODE_SHIFT_1P_24B;
  
  		info->var.red.offset	= 16;
  		info->var.red.length	= 8;
  		info->var.green.offset	= 8;
  		info->var.green.length	= 8;
  		info->var.blue.offset	= 0;
  		info->var.blue.length	= 8;
  		info->fix.visual 	= FB_VISUAL_TRUECOLOR;
  		break;
  
  	default:
  		return -EINVAL;
  	}
  
  	ep93xxfb_writel(fbi, val, EP93XXFB_PIXELMODE);
  	return 0;
  }
  
  static void ep93xxfb_set_timing(struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	unsigned int vlines_total, hclks_total, start, stop;
  
  	vlines_total = info->var.yres + info->var.upper_margin +
  		info->var.lower_margin + info->var.vsync_len - 1;
  
  	hclks_total = info->var.xres + info->var.left_margin +
  		info->var.right_margin + info->var.hsync_len - 1;
  
  	ep93xxfb_out_locked(fbi, vlines_total, EP93XXFB_VLINES_TOTAL);
  	ep93xxfb_out_locked(fbi, hclks_total, EP93XXFB_HCLKS_TOTAL);
  
  	start = vlines_total;
  	stop = vlines_total - info->var.vsync_len;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VSYNC);
  
  	start = vlines_total - info->var.vsync_len - info->var.upper_margin;
  	stop = info->var.lower_margin - 1;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VBLANK);
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VACTIVE);
  
  	start = vlines_total;
  	stop = vlines_total + 1;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_VCLK);
  
  	start = hclks_total;
  	stop = hclks_total - info->var.hsync_len;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HSYNC);
  
  	start = hclks_total - info->var.hsync_len - info->var.left_margin;
  	stop = info->var.right_margin - 1;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HBLANK);
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HACTIVE);
  
  	start = hclks_total;
  	stop = hclks_total;
  	ep93xxfb_out_locked(fbi, start | (stop << 16), EP93XXFB_HCLK);
  
  	ep93xxfb_out_locked(fbi, 0x0, EP93XXFB_LINE_CARRY);
  }
  
  static int ep93xxfb_set_par(struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  
  	clk_set_rate(fbi->clk, 1000 * PICOS2KHZ(info->var.pixclock));
  
  	ep93xxfb_set_timing(info);
  
  	info->fix.line_length = info->var.xres_virtual *
  		info->var.bits_per_pixel / 8;
  
  	ep93xxfb_writel(fbi, info->fix.smem_start, EP93XXFB_SCREEN_PAGE);
  	ep93xxfb_writel(fbi, info->var.yres - 1, EP93XXFB_SCREEN_LINES);
  	ep93xxfb_writel(fbi, ((info->var.xres * info->var.bits_per_pixel)
  			      / 32) - 1, EP93XXFB_LINE_LENGTH);
  	ep93xxfb_writel(fbi, info->fix.line_length / 4, EP93XXFB_VLINE_STEP);
  	ep93xxfb_set_video_attribs(info);
  	return 0;
  }
  
  static int ep93xxfb_check_var(struct fb_var_screeninfo *var,
  			      struct fb_info *info)
  {
  	int err;
  
  	err = ep93xxfb_set_pixelmode(info);
  	if (err)
  		return err;
  
  	var->xres = max_t(unsigned int, var->xres, EP93XXFB_MIN_XRES);
  	var->xres = min_t(unsigned int, var->xres, EP93XXFB_MAX_XRES);
  	var->xres_virtual = max(var->xres_virtual, var->xres);
  
  	var->yres = max_t(unsigned int, var->yres, EP93XXFB_MIN_YRES);
  	var->yres = min_t(unsigned int, var->yres, EP93XXFB_MAX_YRES);
  	var->yres_virtual = max(var->yres_virtual, var->yres);
  
  	return 0;
  }
  
  static int ep93xxfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
  {
  	unsigned int offset = vma->vm_pgoff << PAGE_SHIFT;
  
  	if (offset < info->fix.smem_len) {
  		return dma_mmap_writecombine(info->dev, vma, info->screen_base,
  					     info->fix.smem_start,
  					     info->fix.smem_len);
  	}
  
  	return -EINVAL;
  }
  
  static int ep93xxfb_blank(int blank_mode, struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	unsigned int attribs = ep93xxfb_readl(fbi, EP93XXFB_ATTRIBS);
  
  	if (blank_mode) {
  		if (fbi->mach_info->blank)
  			fbi->mach_info->blank(blank_mode, info);
  		ep93xxfb_out_locked(fbi, attribs & ~EP93XXFB_ENABLE,
  				    EP93XXFB_ATTRIBS);
  		clk_disable(fbi->clk);
  	} else {
  		clk_enable(fbi->clk);
  		ep93xxfb_out_locked(fbi, attribs | EP93XXFB_ENABLE,
  				    EP93XXFB_ATTRIBS);
  		if (fbi->mach_info->blank)
  			fbi->mach_info->blank(blank_mode, info);
  	}
  
  	return 0;
  }
  
  static inline int ep93xxfb_convert_color(int val, int width)
  {
  	return ((val << width) + 0x7fff - val) >> 16;
  }
  
  static int ep93xxfb_setcolreg(unsigned int regno, unsigned int red,
  			      unsigned int green, unsigned int blue,
  			      unsigned int transp, struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	unsigned int *pal = info->pseudo_palette;
  	unsigned int ctrl, i, rgb, lut_current, lut_stat;
  
  	switch (info->fix.visual) {
  	case FB_VISUAL_PSEUDOCOLOR:
  		if (regno > 255)
  			return 1;
  		rgb = ((red & 0xff00) << 8) | (green & 0xff00) |
  			((blue & 0xff00) >> 8);
  
  		pal[regno] = rgb;
  		ep93xxfb_writel(fbi, rgb, (EP93XXFB_COLOR_LUT + (regno << 2)));
  		ctrl = ep93xxfb_readl(fbi, EP93XXFB_LUT_SW_CONTROL);
  		lut_stat = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SSTAT);
  		lut_current = !!(ctrl & EP93XXFB_LUT_SW_CONTROL_SWTCH);
  
  		if (lut_stat == lut_current) {
  			for (i = 0; i < 256; i++) {
  				ep93xxfb_writel(fbi, pal[i],
  					EP93XXFB_COLOR_LUT + (i << 2));
  			}
  
  			ep93xxfb_writel(fbi,
  					ctrl ^ EP93XXFB_LUT_SW_CONTROL_SWTCH,
  					EP93XXFB_LUT_SW_CONTROL);
  		}
  		break;
  
  	case FB_VISUAL_TRUECOLOR:
  		if (regno > 16)
  			return 1;
  
  		red = ep93xxfb_convert_color(red, info->var.red.length);
  		green = ep93xxfb_convert_color(green, info->var.green.length);
  		blue = ep93xxfb_convert_color(blue, info->var.blue.length);
  		transp = ep93xxfb_convert_color(transp,
  						info->var.transp.length);
  
  		pal[regno] = (red << info->var.red.offset) |
  			(green << info->var.green.offset) |
  			(blue << info->var.blue.offset) |
  			(transp << info->var.transp.offset);
  		break;
  
  	default:
  		return 1;
  	}
  
  	return 0;
  }
  
  static struct fb_ops ep93xxfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_check_var	= ep93xxfb_check_var,
  	.fb_set_par	= ep93xxfb_set_par,
  	.fb_blank	= ep93xxfb_blank,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  	.fb_setcolreg	= ep93xxfb_setcolreg,
  	.fb_mmap	= ep93xxfb_mmap,
  };
  
  static int ep93xxfb_calc_fbsize(struct ep93xxfb_mach_info *mach_info)
  {
  	int i, fb_size = 0;
  
  	if (mach_info->num_modes == EP93XXFB_USE_MODEDB) {
  		fb_size = EP93XXFB_MAX_XRES * EP93XXFB_MAX_YRES *
  			mach_info->bpp / 8;
  	} else {
  		for (i = 0; i < mach_info->num_modes; i++) {
  			const struct fb_videomode *mode;
  			int size;
  
  			mode = &mach_info->modes[i];
  			size = mode->xres * mode->yres * mach_info->bpp / 8;
  			if (size > fb_size)
  				fb_size = size;
  		}
  	}
  
  	return fb_size;
  }
  
  static int ep93xxfb_alloc_videomem(struct fb_info *info)
  {
  	struct ep93xx_fbi *fbi = info->par;
  	char __iomem *virt_addr;
  	dma_addr_t phys_addr;
  	unsigned int fb_size;
  
  	fb_size = ep93xxfb_calc_fbsize(fbi->mach_info);
  	virt_addr = dma_alloc_writecombine(info->dev, fb_size,
  					   &phys_addr, GFP_KERNEL);
  	if (!virt_addr)
  		return -ENOMEM;
  
  	/*
  	 * There is a bug in the ep93xx framebuffer which causes problems
  	 * if bit 27 of the physical address is set.
  	 * See: http://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
  	 * There does not seem to be any official errata for this, but I
  	 * have confirmed the problem exists on my hardware (ep9315) at
  	 * least.
  	 */
  	if (check_screenpage_bug && phys_addr & (1 << 27)) {
  		dev_err(info->dev, "ep93xx framebuffer bug. phys addr (0x%x) "
  			"has bit 27 set: cannot init framebuffer
  ",
  			phys_addr);
  
  		dma_free_coherent(info->dev, fb_size, virt_addr, phys_addr);
  		return -ENOMEM;
  	}
  
  	info->fix.smem_start = phys_addr;
  	info->fix.smem_len = fb_size;
  	info->screen_base = virt_addr;
  
  	return 0;
  }
  
  static void ep93xxfb_dealloc_videomem(struct fb_info *info)
  {
  	if (info->screen_base)
  		dma_free_coherent(info->dev, info->fix.smem_len,
  				  info->screen_base, info->fix.smem_start);
  }
  
  static int ep93xxfb_probe(struct platform_device *pdev)
  {
  	struct ep93xxfb_mach_info *mach_info = dev_get_platdata(&pdev->dev);
  	struct fb_info *info;
  	struct ep93xx_fbi *fbi;
  	struct resource *res;
  	char *video_mode;
  	int err;
  
  	if (!mach_info)
  		return -EINVAL;
  
  	info = framebuffer_alloc(sizeof(struct ep93xx_fbi), &pdev->dev);
  	if (!info)
  		return -ENOMEM;
  
  	info->dev = &pdev->dev;
  	platform_set_drvdata(pdev, info);
  	fbi = info->par;
  	fbi->mach_info = mach_info;
  
  	err = fb_alloc_cmap(&info->cmap, 256, 0);
  	if (err)
  		goto failed_cmap;
  
  	err = ep93xxfb_alloc_videomem(info);
  	if (err)
  		goto failed_videomem;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		err = -ENXIO;
  		goto failed_resource;
  	}
  
  	/*
  	 * FIXME - We don't do a request_mem_region here because we are
  	 * sharing the register space with the backlight driver (see
  	 * drivers/video/backlight/ep93xx_bl.c) and doing so will cause
  	 * the second loaded driver to return -EBUSY.
  	 *
  	 * NOTE: No locking is required; the backlight does not touch
  	 * any of the framebuffer registers.
  	 */
  	fbi->res = res;
  	fbi->mmio_base = devm_ioremap(&pdev->dev, res->start,
  				      resource_size(res));
  	if (!fbi->mmio_base) {
  		err = -ENXIO;
  		goto failed_resource;
  	}
  
  	strcpy(info->fix.id, pdev->name);
  	info->fbops		= &ep93xxfb_ops;
  	info->fix.type		= FB_TYPE_PACKED_PIXELS;
  	info->fix.accel		= FB_ACCEL_NONE;
  	info->var.activate	= FB_ACTIVATE_NOW;
  	info->var.vmode		= FB_VMODE_NONINTERLACED;
  	info->flags		= FBINFO_DEFAULT;
  	info->node		= -1;
  	info->state		= FBINFO_STATE_RUNNING;
  	info->pseudo_palette	= &fbi->pseudo_palette;
  
  	fb_get_options("ep93xx-fb", &video_mode);
  	err = fb_find_mode(&info->var, info, video_mode,
  			   fbi->mach_info->modes, fbi->mach_info->num_modes,
  			   fbi->mach_info->default_mode, fbi->mach_info->bpp);
  	if (err == 0) {
  		dev_err(info->dev, "No suitable video mode found
  ");
  		err = -EINVAL;
  		goto failed_resource;
  	}
  
  	if (mach_info->setup) {
  		err = mach_info->setup(pdev);
  		if (err)
  			goto failed_resource;
  	}
  
  	err = ep93xxfb_check_var(&info->var, info);
  	if (err)
  		goto failed_check;
  
  	fbi->clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(fbi->clk)) {
  		err = PTR_ERR(fbi->clk);
  		fbi->clk = NULL;
  		goto failed_check;
  	}
  
  	ep93xxfb_set_par(info);
  	clk_enable(fbi->clk);
  
  	err = register_framebuffer(info);
  	if (err)
  		goto failed_check;
  
  	dev_info(info->dev, "registered. Mode = %dx%d-%d
  ",
  		 info->var.xres, info->var.yres, info->var.bits_per_pixel);
  	return 0;
  
  failed_check:
  	if (fbi->mach_info->teardown)
  		fbi->mach_info->teardown(pdev);
  failed_resource:
  	ep93xxfb_dealloc_videomem(info);
  failed_videomem:
  	fb_dealloc_cmap(&info->cmap);
  failed_cmap:
  	kfree(info);
  
  	return err;
  }
  
  static int ep93xxfb_remove(struct platform_device *pdev)
  {
  	struct fb_info *info = platform_get_drvdata(pdev);
  	struct ep93xx_fbi *fbi = info->par;
  
  	unregister_framebuffer(info);
  	clk_disable(fbi->clk);
  	ep93xxfb_dealloc_videomem(info);
  	fb_dealloc_cmap(&info->cmap);
  
  	if (fbi->mach_info->teardown)
  		fbi->mach_info->teardown(pdev);
  
  	kfree(info);
  
  	return 0;
  }
  
  static struct platform_driver ep93xxfb_driver = {
  	.probe		= ep93xxfb_probe,
  	.remove		= ep93xxfb_remove,
  	.driver = {
  		.name	= "ep93xx-fb",
  		.owner	= THIS_MODULE,
  	},
  };
  module_platform_driver(ep93xxfb_driver);
  
  MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
  MODULE_ALIAS("platform:ep93xx-fb");
  MODULE_AUTHOR("Ryan Mallon, "
  	      "H Hartley Sweeten <hsweeten@visionengravers.com");
  MODULE_LICENSE("GPL");