text: /*
   *  linux/drivers/video/amba-clcd.c
   *
   * Copyright (C) 2001 ARM Limited, by David A Rusling
   * Updated to 2.5, Deep Blue Solutions Ltd.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details.
   *
   *  ARM PrimeCell PL110 Color LCD Controller
   */
  #include <linux/amba/bus.h>
  #include <linux/amba/clcd.h>
  #include <linux/backlight.h>
  #include <linux/clk.h>
  #include <linux/delay.h>
  #include <linux/dma-mapping.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/list.h>
  #include <linux/mm.h>
  #include <linux/module.h>
  #include <linux/of_address.h>
  #include <linux/of_graph.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <video/display_timing.h>
  #include <video/of_display_timing.h>
  #include <video/videomode.h>
  
  #define to_clcd(info)	container_of(info, struct clcd_fb, fb)
  
  /* This is limited to 16 characters when displayed by X startup */
  static const char *clcd_name = "CLCD FB";
  
  /*
   * Unfortunately, the enable/disable functions may be called either from
   * process or IRQ context, and we _need_ to delay.  This is _not_ good.
   */
  static inline void clcdfb_sleep(unsigned int ms)
  {
  	if (in_atomic()) {
  		mdelay(ms);
  	} else {
  		msleep(ms);
  	}
  }
  
  static inline void clcdfb_set_start(struct clcd_fb *fb)
  {
  	unsigned long ustart = fb->fb.fix.smem_start;
  	unsigned long lstart;
  
  	ustart += fb->fb.var.yoffset * fb->fb.fix.line_length;
  	lstart = ustart + fb->fb.var.yres * fb->fb.fix.line_length / 2;
  
  	writel(ustart, fb->regs + CLCD_UBAS);
  	writel(lstart, fb->regs + CLCD_LBAS);
  }
  
  static void clcdfb_disable(struct clcd_fb *fb)
  {
  	u32 val;
  
  	if (fb->board->disable)
  		fb->board->disable(fb);
  
  	if (fb->panel->backlight) {
  		fb->panel->backlight->props.power = FB_BLANK_POWERDOWN;
  		backlight_update_status(fb->panel->backlight);
  	}
  
  	val = readl(fb->regs + fb->off_cntl);
  	if (val & CNTL_LCDPWR) {
  		val &= ~CNTL_LCDPWR;
  		writel(val, fb->regs + fb->off_cntl);
  
  		clcdfb_sleep(20);
  	}
  	if (val & CNTL_LCDEN) {
  		val &= ~CNTL_LCDEN;
  		writel(val, fb->regs + fb->off_cntl);
  	}
  
  	/*
  	 * Disable CLCD clock source.
  	 */
  	if (fb->clk_enabled) {
  		fb->clk_enabled = false;
  		clk_disable(fb->clk);
  	}
  }
  
  static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
  {
  	/*
  	 * Enable the CLCD clock source.
  	 */
  	if (!fb->clk_enabled) {
  		fb->clk_enabled = true;
  		clk_enable(fb->clk);
  	}
  
  	/*
  	 * Bring up by first enabling..
  	 */
  	cntl |= CNTL_LCDEN;
  	writel(cntl, fb->regs + fb->off_cntl);
  
  	clcdfb_sleep(20);
  
  	/*
  	 * and now apply power.
  	 */
  	cntl |= CNTL_LCDPWR;
  	writel(cntl, fb->regs + fb->off_cntl);
  
  	/*
  	 * Turn on backlight
  	 */
  	if (fb->panel->backlight) {
  		fb->panel->backlight->props.power = FB_BLANK_UNBLANK;
  		backlight_update_status(fb->panel->backlight);
  	}
  
  	/*
  	 * finally, enable the interface.
  	 */
  	if (fb->board->enable)
  		fb->board->enable(fb);
  }
  
  static int
  clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
  {
  	u32 caps;
  	int ret = 0;
  
  	if (fb->panel->caps && fb->board->caps)
  		caps = fb->panel->caps & fb->board->caps;
  	else {
  		/* Old way of specifying what can be used */
  		caps = fb->panel->cntl & CNTL_BGR ?
  			CLCD_CAP_BGR : CLCD_CAP_RGB;
  		/* But mask out 444 modes as they weren't supported */
  		caps &= ~CLCD_CAP_444;
  	}
  
  	/* Only TFT panels can do RGB888/BGR888 */
  	if (!(fb->panel->cntl & CNTL_LCDTFT))
  		caps &= ~CLCD_CAP_888;
  
  	memset(&var->transp, 0, sizeof(var->transp));
  
  	var->red.msb_right = 0;
  	var->green.msb_right = 0;
  	var->blue.msb_right = 0;
  
  	switch (var->bits_per_pixel) {
  	case 1:
  	case 2:
  	case 4:
  	case 8:
  		/* If we can't do 5551, reject */
  		caps &= CLCD_CAP_5551;
  		if (!caps) {
  			ret = -EINVAL;
  			break;
  		}
  
  		var->red.length		= var->bits_per_pixel;
  		var->red.offset		= 0;
  		var->green.length	= var->bits_per_pixel;
  		var->green.offset	= 0;
  		var->blue.length	= var->bits_per_pixel;
  		var->blue.offset	= 0;
  		break;
  
  	case 16:
  		/* If we can't do 444, 5551 or 565, reject */
  		if (!(caps & (CLCD_CAP_444 | CLCD_CAP_5551 | CLCD_CAP_565))) {
  			ret = -EINVAL;
  			break;
  		}
  
  		/*
  		 * Green length can be 4, 5 or 6 depending whether
  		 * we're operating in 444, 5551 or 565 mode.
  		 */
  		if (var->green.length == 4 && caps & CLCD_CAP_444)
  			caps &= CLCD_CAP_444;
  		if (var->green.length == 5 && caps & CLCD_CAP_5551)
  			caps &= CLCD_CAP_5551;
  		else if (var->green.length == 6 && caps & CLCD_CAP_565)
  			caps &= CLCD_CAP_565;
  		else {
  			/*
  			 * PL110 officially only supports RGB555,
  			 * but may be wired up to allow RGB565.
  			 */
  			if (caps & CLCD_CAP_565) {
  				var->green.length = 6;
  				caps &= CLCD_CAP_565;
  			} else if (caps & CLCD_CAP_5551) {
  				var->green.length = 5;
  				caps &= CLCD_CAP_5551;
  			} else {
  				var->green.length = 4;
  				caps &= CLCD_CAP_444;
  			}
  		}
  
  		if (var->green.length >= 5) {
  			var->red.length = 5;
  			var->blue.length = 5;
  		} else {
  			var->red.length = 4;
  			var->blue.length = 4;
  		}
  		break;
  	case 32:
  		/* If we can't do 888, reject */
  		caps &= CLCD_CAP_888;
  		if (!caps) {
  			ret = -EINVAL;
  			break;
  		}
  
  		var->red.length = 8;
  		var->green.length = 8;
  		var->blue.length = 8;
  		break;
  	default:
  		ret = -EINVAL;
  		break;
  	}
  
  	/*
  	 * >= 16bpp displays have separate colour component bitfields
  	 * encoded in the pixel data.  Calculate their position from
  	 * the bitfield length defined above.
  	 */
  	if (ret == 0 && var->bits_per_pixel >= 16) {
  		bool bgr, rgb;
  
  		bgr = caps & CLCD_CAP_BGR && var->blue.offset == 0;
  		rgb = caps & CLCD_CAP_RGB && var->red.offset == 0;
  
  		if (!bgr && !rgb)
  			/*
  			 * The requested format was not possible, try just
  			 * our capabilities.  One of BGR or RGB must be
  			 * supported.
  			 */
  			bgr = caps & CLCD_CAP_BGR;
  
  		if (bgr) {
  			var->blue.offset = 0;
  			var->green.offset = var->blue.offset + var->blue.length;
  			var->red.offset = var->green.offset + var->green.length;
  		} else {
  			var->red.offset = 0;
  			var->green.offset = var->red.offset + var->red.length;
  			var->blue.offset = var->green.offset + var->green.length;
  		}
  	}
  
  	return ret;
  }
  
  static int clcdfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
  {
  	struct clcd_fb *fb = to_clcd(info);
  	int ret = -EINVAL;
  
  	if (fb->board->check)
  		ret = fb->board->check(fb, var);
  
  	if (ret == 0 &&
  	    var->xres_virtual * var->bits_per_pixel / 8 *
  	    var->yres_virtual > fb->fb.fix.smem_len)
  		ret = -EINVAL;
  
  	if (ret == 0)
  		ret = clcdfb_set_bitfields(fb, var);
  
  	return ret;
  }
  
  static int clcdfb_set_par(struct fb_info *info)
  {
  	struct clcd_fb *fb = to_clcd(info);
  	struct clcd_regs regs;
  
  	fb->fb.fix.line_length = fb->fb.var.xres_virtual *
  				 fb->fb.var.bits_per_pixel / 8;
  
  	if (fb->fb.var.bits_per_pixel <= 8)
  		fb->fb.fix.visual = FB_VISUAL_PSEUDOCOLOR;
  	else
  		fb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
  
  	fb->board->decode(fb, &regs);
  
  	clcdfb_disable(fb);
  
  	writel(regs.tim0, fb->regs + CLCD_TIM0);
  	writel(regs.tim1, fb->regs + CLCD_TIM1);
  	writel(regs.tim2, fb->regs + CLCD_TIM2);
  	writel(regs.tim3, fb->regs + CLCD_TIM3);
  
  	clcdfb_set_start(fb);
  
  	clk_set_rate(fb->clk, (1000000000 / regs.pixclock) * 1000);
  
  	fb->clcd_cntl = regs.cntl;
  
  	clcdfb_enable(fb, regs.cntl);
  
  #ifdef DEBUG
  	printk(KERN_INFO
  	       "CLCD: Registers set to\n"
  	       "  %08x %08x %08x %08x\n"
  	       "  %08x %08x %08x %08x\n",
  		readl(fb->regs + CLCD_TIM0), readl(fb->regs + CLCD_TIM1),
  		readl(fb->regs + CLCD_TIM2), readl(fb->regs + CLCD_TIM3),
  		readl(fb->regs + CLCD_UBAS), readl(fb->regs + CLCD_LBAS),
  		readl(fb->regs + fb->off_ienb), readl(fb->regs + fb->off_cntl));
  #endif
  
  	return 0;
  }
  
  static inline u32 convert_bitfield(int val, struct fb_bitfield *bf)
  {
  	unsigned int mask = (1 << bf->length) - 1;
  
  	return (val >> (16 - bf->length) & mask) << bf->offset;
  }
  
  /*
   *  Set a single color register. The values supplied have a 16 bit
   *  magnitude.  Return != 0 for invalid regno.
   */
  static int
  clcdfb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
  		 unsigned int blue, unsigned int transp, struct fb_info *info)
  {
  	struct clcd_fb *fb = to_clcd(info);
  
  	if (regno < 16)
  		fb->cmap[regno] = convert_bitfield(transp, &fb->fb.var.transp) |
  				  convert_bitfield(blue, &fb->fb.var.blue) |
  				  convert_bitfield(green, &fb->fb.var.green) |
  				  convert_bitfield(red, &fb->fb.var.red);
  
  	if (fb->fb.fix.visual == FB_VISUAL_PSEUDOCOLOR && regno < 256) {
  		int hw_reg = CLCD_PALETTE + ((regno * 2) & ~3);
  		u32 val, mask, newval;
  
  		newval  = (red >> 11)  & 0x001f;
  		newval |= (green >> 6) & 0x03e0;
  		newval |= (blue >> 1)  & 0x7c00;
  
  		/*
  		 * 3.2.11: if we're configured for big endian
  		 * byte order, the palette entries are swapped.
  		 */
  		if (fb->clcd_cntl & CNTL_BEBO)
  			regno ^= 1;
  
  		if (regno & 1) {
  			newval <<= 16;
  			mask = 0x0000ffff;
  		} else {
  			mask = 0xffff0000;
  		}
  
  		val = readl(fb->regs + hw_reg) & mask;
  		writel(val | newval, fb->regs + hw_reg);
  	}
  
  	return regno > 255;
  }
  
  /*
   *  Blank the screen if blank_mode != 0, else unblank. If blank == NULL
   *  then the caller blanks by setting the CLUT (Color Look Up Table) to all
   *  black. Return 0 if blanking succeeded, != 0 if un-/blanking failed due
   *  to e.g. a video mode which doesn't support it. Implements VESA suspend
   *  and powerdown modes on hardware that supports disabling hsync/vsync:
   *    blank_mode == 2: suspend vsync
   *    blank_mode == 3: suspend hsync
   *    blank_mode == 4: powerdown
   */
  static int clcdfb_blank(int blank_mode, struct fb_info *info)
  {
  	struct clcd_fb *fb = to_clcd(info);
  
  	if (blank_mode != 0) {
  		clcdfb_disable(fb);
  	} else {
  		clcdfb_enable(fb, fb->clcd_cntl);
  	}
  	return 0;
  }
  
  static int clcdfb_mmap(struct fb_info *info,
  		       struct vm_area_struct *vma)
  {
  	struct clcd_fb *fb = to_clcd(info);
  	unsigned long len, off = vma->vm_pgoff << PAGE_SHIFT;
  	int ret = -EINVAL;
  
  	len = info->fix.smem_len;
  
  	if (off <= len && vma->vm_end - vma->vm_start <= len - off &&
  	    fb->board->mmap)
  		ret = fb->board->mmap(fb, vma);
  
  	return ret;
  }
  
  static const struct fb_ops clcdfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_check_var	= clcdfb_check_var,
  	.fb_set_par	= clcdfb_set_par,
  	.fb_setcolreg	= clcdfb_setcolreg,
  	.fb_blank	= clcdfb_blank,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  	.fb_mmap	= clcdfb_mmap,
  };
  
  static int clcdfb_register(struct clcd_fb *fb)
  {
  	int ret;
  
  	/*
  	 * ARM PL111 always has IENB at 0x1c; it's only PL110
  	 * which is reversed on some platforms.
  	 */
  	if (amba_manf(fb->dev) == 0x41 && amba_part(fb->dev) == 0x111) {
  		fb->off_ienb = CLCD_PL111_IENB;
  		fb->off_cntl = CLCD_PL111_CNTL;
  	} else {
  		fb->off_ienb = CLCD_PL110_IENB;
  		fb->off_cntl = CLCD_PL110_CNTL;
  	}
  
  	fb->clk = clk_get(&fb->dev->dev, NULL);
  	if (IS_ERR(fb->clk)) {
  		ret = PTR_ERR(fb->clk);
  		goto out;
  	}
  
  	ret = clk_prepare(fb->clk);
  	if (ret)
  		goto free_clk;
  
  	fb->fb.device		= &fb->dev->dev;
  
  	fb->fb.fix.mmio_start	= fb->dev->res.start;
  	fb->fb.fix.mmio_len	= resource_size(&fb->dev->res);
  
  	fb->regs = ioremap(fb->fb.fix.mmio_start, fb->fb.fix.mmio_len);
  	if (!fb->regs) {
  		printk(KERN_ERR "CLCD: unable to remap registers\n");
  		ret = -ENOMEM;
  		goto clk_unprep;
  	}
  
  	fb->fb.fbops		= &clcdfb_ops;
  	fb->fb.flags		= FBINFO_FLAG_DEFAULT;
  	fb->fb.pseudo_palette	= fb->cmap;
  
  	strncpy(fb->fb.fix.id, clcd_name, sizeof(fb->fb.fix.id));
  	fb->fb.fix.type		= FB_TYPE_PACKED_PIXELS;
  	fb->fb.fix.type_aux	= 0;
  	fb->fb.fix.xpanstep	= 0;
  	fb->fb.fix.ypanstep	= 0;
  	fb->fb.fix.ywrapstep	= 0;
  	fb->fb.fix.accel	= FB_ACCEL_NONE;
  
  	fb->fb.var.xres		= fb->panel->mode.xres;
  	fb->fb.var.yres		= fb->panel->mode.yres;
  	fb->fb.var.xres_virtual	= fb->panel->mode.xres;
  	fb->fb.var.yres_virtual	= fb->panel->mode.yres;
  	fb->fb.var.bits_per_pixel = fb->panel->bpp;
  	fb->fb.var.grayscale	= fb->panel->grayscale;
  	fb->fb.var.pixclock	= fb->panel->mode.pixclock;
  	fb->fb.var.left_margin	= fb->panel->mode.left_margin;
  	fb->fb.var.right_margin	= fb->panel->mode.right_margin;
  	fb->fb.var.upper_margin	= fb->panel->mode.upper_margin;
  	fb->fb.var.lower_margin	= fb->panel->mode.lower_margin;
  	fb->fb.var.hsync_len	= fb->panel->mode.hsync_len;
  	fb->fb.var.vsync_len	= fb->panel->mode.vsync_len;
  	fb->fb.var.sync		= fb->panel->mode.sync;
  	fb->fb.var.vmode	= fb->panel->mode.vmode;
  	fb->fb.var.activate	= FB_ACTIVATE_NOW;
  	fb->fb.var.nonstd	= 0;
  	fb->fb.var.height	= fb->panel->height;
  	fb->fb.var.width	= fb->panel->width;
  	fb->fb.var.accel_flags	= 0;
  
  	fb->fb.monspecs.hfmin	= 0;
  	fb->fb.monspecs.hfmax   = 100000;
  	fb->fb.monspecs.vfmin	= 0;
  	fb->fb.monspecs.vfmax	= 400;
  	fb->fb.monspecs.dclkmin = 1000000;
  	fb->fb.monspecs.dclkmax	= 100000000;
  
  	/*
  	 * Make sure that the bitfields are set appropriately.
  	 */
  	clcdfb_set_bitfields(fb, &fb->fb.var);
  
  	/*
  	 * Allocate colourmap.
  	 */
  	ret = fb_alloc_cmap(&fb->fb.cmap, 256, 0);
  	if (ret)
  		goto unmap;
  
  	/*
  	 * Ensure interrupts are disabled.
  	 */
  	writel(0, fb->regs + fb->off_ienb);
  
  	fb_set_var(&fb->fb, &fb->fb.var);
  
  	dev_info(&fb->dev->dev, "%s hardware, %s display\n",
  	         fb->board->name, fb->panel->mode.name);
  
  	ret = register_framebuffer(&fb->fb);
  	if (ret == 0)
  		goto out;
  
  	printk(KERN_ERR "CLCD: cannot register framebuffer (%d)\n", ret);
  
  	fb_dealloc_cmap(&fb->fb.cmap);
   unmap:
  	iounmap(fb->regs);
   clk_unprep:
  	clk_unprepare(fb->clk);
   free_clk:
  	clk_put(fb->clk);
   out:
  	return ret;
  }
  
  #ifdef CONFIG_OF
  static int clcdfb_of_get_dpi_panel_mode(struct device_node *node,
  		struct clcd_panel *clcd_panel)
  {
  	int err;
  	struct display_timing timing;
  	struct videomode video;
  
  	err = of_get_display_timing(node, "panel-timing", &timing);
  	if (err) {
  		pr_err("%pOF: problems parsing panel-timing (%d)\n", node, err);
  		return err;
  	}
  
  	videomode_from_timing(&timing, &video);
  
  	err = fb_videomode_from_videomode(&video, &clcd_panel->mode);
  	if (err)
  		return err;
  
  	/* Set up some inversion flags */
  	if (timing.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
  		clcd_panel->tim2 |= TIM2_IPC;
  	else if (!(timing.flags & DISPLAY_FLAGS_PIXDATA_POSEDGE))
  		/*
  		 * To preserve backwards compatibility, the IPC (inverted
  		 * pixel clock) flag needs to be set on any display that
  		 * doesn't explicitly specify that the pixel clock is
  		 * active on the negative or positive edge.
  		 */
  		clcd_panel->tim2 |= TIM2_IPC;
  
  	if (timing.flags & DISPLAY_FLAGS_HSYNC_LOW)
  		clcd_panel->tim2 |= TIM2_IHS;
  
  	if (timing.flags & DISPLAY_FLAGS_VSYNC_LOW)
  		clcd_panel->tim2 |= TIM2_IVS;
  
  	if (timing.flags & DISPLAY_FLAGS_DE_LOW)
  		clcd_panel->tim2 |= TIM2_IOE;
  
  	return 0;
  }
  
  static int clcdfb_snprintf_mode(char *buf, int size, struct fb_videomode *mode)
  {
  	return snprintf(buf, size, "%ux%u@%u", mode->xres, mode->yres,
  			mode->refresh);
  }
  
  static int clcdfb_of_get_backlight(struct device *dev,
  				   struct clcd_panel *clcd_panel)
  {
  	struct backlight_device *backlight;
  
  	/* Look up the optional backlight device */
  	backlight = devm_of_find_backlight(dev);
  	if (IS_ERR(backlight))
  		return PTR_ERR(backlight);
  
  	clcd_panel->backlight = backlight;
  	return 0;
  }
  
  static int clcdfb_of_get_mode(struct device *dev, struct device_node *panel,
  			      struct clcd_panel *clcd_panel)
  {
  	int err;
  	struct fb_videomode *mode;
  	char *name;
  	int len;
  
  	/* Only directly connected DPI panels supported for now */
  	if (of_device_is_compatible(panel, "panel-dpi"))
  		err = clcdfb_of_get_dpi_panel_mode(panel, clcd_panel);
  	else
  		err = -ENOENT;
  	if (err)
  		return err;
  	mode = &clcd_panel->mode;
  
  	len = clcdfb_snprintf_mode(NULL, 0, mode);
  	name = devm_kzalloc(dev, len + 1, GFP_KERNEL);
  	if (!name)
  		return -ENOMEM;
  
  	clcdfb_snprintf_mode(name, len + 1, mode);
  	mode->name = name;
  
  	return 0;
  }
  
  static int clcdfb_of_init_tft_panel(struct clcd_fb *fb, u32 r0, u32 g0, u32 b0)
  {
  	static struct {
  		unsigned int part;
  		u32 r0, g0, b0;
  		u32 caps;
  	} panels[] = {
  		{ 0x110, 1,  7, 13, CLCD_CAP_5551 },
  		{ 0x110, 0,  8, 16, CLCD_CAP_888 },
  		{ 0x110, 16, 8, 0,  CLCD_CAP_888 },
  		{ 0x111, 4, 14, 20, CLCD_CAP_444 },
  		{ 0x111, 3, 11, 19, CLCD_CAP_444 | CLCD_CAP_5551 },
  		{ 0x111, 3, 10, 19, CLCD_CAP_444 | CLCD_CAP_5551 |
  				    CLCD_CAP_565 },
  		{ 0x111, 0,  8, 16, CLCD_CAP_444 | CLCD_CAP_5551 |
  				    CLCD_CAP_565 | CLCD_CAP_888 },
  	};
  	int i;
  
  	/* Bypass pixel clock divider */
  	fb->panel->tim2 |= TIM2_BCD;
  
  	/* TFT display, vert. comp. interrupt at the start of the back porch */
  	fb->panel->cntl |= CNTL_LCDTFT | CNTL_LCDVCOMP(1);
  
  	fb->panel->caps = 0;
  
  	/* Match the setup with known variants */
  	for (i = 0; i < ARRAY_SIZE(panels) && !fb->panel->caps; i++) {
  		if (amba_part(fb->dev) != panels[i].part)
  			continue;
  		if (g0 != panels[i].g0)
  			continue;
  		if (r0 == panels[i].r0 && b0 == panels[i].b0)
  			fb->panel->caps = panels[i].caps;
  	}
  
  	/*
  	 * If we actually physically connected the R lines to B and
  	 * vice versa
  	 */
  	if (r0 != 0 && b0 == 0)
  		fb->panel->bgr_connection = true;
  
  	return fb->panel->caps ? 0 : -EINVAL;
  }
  
  static int clcdfb_of_init_display(struct clcd_fb *fb)
  {
  	struct device_node *endpoint, *panel;
  	int err;
  	unsigned int bpp;
  	u32 max_bandwidth;
  	u32 tft_r0b0g0[3];
  
  	fb->panel = devm_kzalloc(&fb->dev->dev, sizeof(*fb->panel), GFP_KERNEL);
  	if (!fb->panel)
  		return -ENOMEM;
  
  	/*
  	 * Fetch the panel endpoint.
  	 */
  	endpoint = of_graph_get_next_endpoint(fb->dev->dev.of_node, NULL);
  	if (!endpoint)
  		return -ENODEV;
  
  	panel = of_graph_get_remote_port_parent(endpoint);
  	if (!panel)
  		return -ENODEV;
  
  	err = clcdfb_of_get_backlight(&fb->dev->dev, fb->panel);
  	if (err)
  		return err;
  
  	err = clcdfb_of_get_mode(&fb->dev->dev, panel, fb->panel);
  	if (err)
  		return err;
  
  	err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth",
  			&max_bandwidth);
  	if (!err) {
  		/*
  		 * max_bandwidth is in bytes per second and pixclock in
  		 * pico-seconds, so the maximum allowed bits per pixel is
  		 *   8 * max_bandwidth / (PICOS2KHZ(pixclock) * 1000)
  		 * Rearrange this calculation to avoid overflow and then ensure
  		 * result is a valid format.
  		 */
  		bpp = max_bandwidth / (1000 / 8)
  			/ PICOS2KHZ(fb->panel->mode.pixclock);
  		bpp = rounddown_pow_of_two(bpp);
  		if (bpp > 32)
  			bpp = 32;
  	} else
  		bpp = 32;
  	fb->panel->bpp = bpp;
  
  #ifdef CONFIG_CPU_BIG_ENDIAN
  	fb->panel->cntl |= CNTL_BEBO;
  #endif
  	fb->panel->width = -1;
  	fb->panel->height = -1;
  
  	if (of_property_read_u32_array(endpoint,
  			"arm,pl11x,tft-r0g0b0-pads",
  			tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) != 0)
  		return -ENOENT;
  
  	return clcdfb_of_init_tft_panel(fb, tft_r0b0g0[0],
  					tft_r0b0g0[1],  tft_r0b0g0[2]);
  }
  
  static int clcdfb_of_vram_setup(struct clcd_fb *fb)
  {
  	int err;
  	struct device_node *memory;
  	u64 size;
  
  	err = clcdfb_of_init_display(fb);
  	if (err)
  		return err;
  
  	memory = of_parse_phandle(fb->dev->dev.of_node, "memory-region", 0);
  	if (!memory)
  		return -ENODEV;
  
  	fb->fb.screen_base = of_iomap(memory, 0);
  	if (!fb->fb.screen_base)
  		return -ENOMEM;
  
  	fb->fb.fix.smem_start = of_translate_address(memory,
  			of_get_address(memory, 0, &size, NULL));
  	fb->fb.fix.smem_len = size;
  
  	return 0;
  }
  
  static int clcdfb_of_vram_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
  {
  	unsigned long off, user_size, kernel_size;
  
  
  	off = vma->vm_pgoff << PAGE_SHIFT;
  	user_size = vma->vm_end - vma->vm_start;
  	kernel_size = fb->fb.fix.smem_len;
  
  	if (off >= kernel_size || user_size > (kernel_size - off))
  		return -ENXIO;
  
  	return remap_pfn_range(vma, vma->vm_start,
  			__phys_to_pfn(fb->fb.fix.smem_start) + vma->vm_pgoff,
  			user_size,
  			pgprot_writecombine(vma->vm_page_prot));
  }
  
  static void clcdfb_of_vram_remove(struct clcd_fb *fb)
  {
  	iounmap(fb->fb.screen_base);
  }
  
  static int clcdfb_of_dma_setup(struct clcd_fb *fb)
  {
  	unsigned long framesize;
  	dma_addr_t dma;
  	int err;
  
  	err = clcdfb_of_init_display(fb);
  	if (err)
  		return err;
  
  	framesize = PAGE_ALIGN(fb->panel->mode.xres * fb->panel->mode.yres *
  			fb->panel->bpp / 8);
  	fb->fb.screen_base = dma_alloc_coherent(&fb->dev->dev, framesize,
  			&dma, GFP_KERNEL);
  	if (!fb->fb.screen_base)
  		return -ENOMEM;
  
  	fb->fb.fix.smem_start = dma;
  	fb->fb.fix.smem_len = framesize;
  
  	return 0;
  }
  
  static int clcdfb_of_dma_mmap(struct clcd_fb *fb, struct vm_area_struct *vma)
  {
  	return dma_mmap_wc(&fb->dev->dev, vma, fb->fb.screen_base,
  			   fb->fb.fix.smem_start, fb->fb.fix.smem_len);
  }
  
  static void clcdfb_of_dma_remove(struct clcd_fb *fb)
  {
  	dma_free_coherent(&fb->dev->dev, fb->fb.fix.smem_len,
  			fb->fb.screen_base, fb->fb.fix.smem_start);
  }
  
  static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
  {
  	struct clcd_board *board = devm_kzalloc(&dev->dev, sizeof(*board),
  			GFP_KERNEL);
  	struct device_node *node = dev->dev.of_node;
  
  	if (!board)
  		return NULL;
  
  	board->name = of_node_full_name(node);
  	board->caps = CLCD_CAP_ALL;
  	board->check = clcdfb_check;
  	board->decode = clcdfb_decode;
  	if (of_find_property(node, "memory-region", NULL)) {
  		board->setup = clcdfb_of_vram_setup;
  		board->mmap = clcdfb_of_vram_mmap;
  		board->remove = clcdfb_of_vram_remove;
  	} else {
  		board->setup = clcdfb_of_dma_setup;
  		board->mmap = clcdfb_of_dma_mmap;
  		board->remove = clcdfb_of_dma_remove;
  	}
  
  	return board;
  }
  #else
  static struct clcd_board *clcdfb_of_get_board(struct amba_device *dev)
  {
  	return NULL;
  }
  #endif
  
  static int clcdfb_probe(struct amba_device *dev, const struct amba_id *id)
  {
  	struct clcd_board *board = dev_get_platdata(&dev->dev);
  	struct clcd_fb *fb;
  	int ret;
  
  	if (!board)
  		board = clcdfb_of_get_board(dev);
  
  	if (!board)
  		return -EINVAL;
  
  	ret = dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32));
  	if (ret)
  		goto out;
  
  	ret = amba_request_regions(dev, NULL);
  	if (ret) {
  		printk(KERN_ERR "CLCD: unable to reserve regs region\n");
  		goto out;
  	}
  
  	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
  	if (!fb) {
  		ret = -ENOMEM;
  		goto free_region;
  	}
  
  	fb->dev = dev;
  	fb->board = board;
  
  	dev_info(&fb->dev->dev, "PL%03x designer %02x rev%u at 0x%08llx\n",
  		amba_part(dev), amba_manf(dev), amba_rev(dev),
  		(unsigned long long)dev->res.start);
  
  	ret = fb->board->setup(fb);
  	if (ret)
  		goto free_fb;
  
  	ret = clcdfb_register(fb);
  	if (ret == 0) {
  		amba_set_drvdata(dev, fb);
  		goto out;
  	}
  
  	fb->board->remove(fb);
   free_fb:
  	kfree(fb);
   free_region:
  	amba_release_regions(dev);
   out:
  	return ret;
  }
  
  static int clcdfb_remove(struct amba_device *dev)
  {
  	struct clcd_fb *fb = amba_get_drvdata(dev);
  
  	clcdfb_disable(fb);
  	unregister_framebuffer(&fb->fb);
  	if (fb->fb.cmap.len)
  		fb_dealloc_cmap(&fb->fb.cmap);
  	iounmap(fb->regs);
  	clk_unprepare(fb->clk);
  	clk_put(fb->clk);
  
  	fb->board->remove(fb);
  
  	kfree(fb);
  
  	amba_release_regions(dev);
  
  	return 0;
  }
  
  static const struct amba_id clcdfb_id_table[] = {
  	{
  		.id	= 0x00041110,
  		.mask	= 0x000ffffe,
  	},
  	{ 0, 0 },
  };
  
  MODULE_DEVICE_TABLE(amba, clcdfb_id_table);
  
  static struct amba_driver clcd_driver = {
  	.drv 		= {
  		.name	= "clcd-pl11x",
  	},
  	.probe		= clcdfb_probe,
  	.remove		= clcdfb_remove,
  	.id_table	= clcdfb_id_table,
  };
  
  static int __init amba_clcdfb_init(void)
  {
  	if (fb_get_options("ambafb", NULL))
  		return -ENODEV;
  
  	return amba_driver_register(&clcd_driver);
  }
  
  module_init(amba_clcdfb_init);
  
  static void __exit amba_clcdfb_exit(void)
  {
  	amba_driver_unregister(&clcd_driver);
  }
  
  module_exit(amba_clcdfb_exit);
  
  MODULE_DESCRIPTION("ARM PrimeCell PL110 CLCD core driver");
  MODULE_LICENSE("GPL");
  