ep93xx video driver

EP93xx video driver plus documentation.
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Daniele Venzano <linux@brownhat.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/fb/ep93xx-fb.txt

+================================
+Driver for EP93xx LCD controller
+================================
+
+The EP93xx LCD controller can drive both standard desktop monitors and
+embedded LCD displays. If you have a standard desktop monitor then you
+can use the standard Linux video mode database. In your board file:
+
+	static struct ep93xxfb_mach_info some_board_fb_info = {
+		.num_modes	= EP93XXFB_USE_MODEDB,
+		.bpp		= 16,
+	};
+
+If you have an embedded LCD display then you need to define a video
+mode for it as follows:
+
+	static struct fb_videomode some_board_video_modes[] = {
+		{
+			.name		= "some_lcd_name",
+			/* Pixel clock, porches, etc */
+		},
+	};
+
+Note that the pixel clock value is in pico-seconds. You can use the
+KHZ2PICOS macro to convert the pixel clock value. Most other values
+are in pixel clocks. See Documentation/fb/framebuffer.txt for further
+details.
+
+The ep93xxfb_mach_info structure for your board should look like the
+following:
+
+	static struct ep93xxfb_mach_info some_board_fb_info = {
+		.num_modes	= ARRAY_SIZE(some_board_video_modes),
+		.modes		= some_board_video_modes,
+		.default_mode	= &some_board_video_modes[0],
+		.bpp		= 16,
+	};
+
+The framebuffer device can be registered by adding the following to
+your board initialisation function:
+
+	ep93xx_register_fb(&some_board_fb_info);
+
+=====================
+Video Attribute Flags
+=====================
+
+The ep93xxfb_mach_info structure has a flags field which can be used
+to configure the controller. The video attributes flags are fully
+documented in section 7 of the EP93xx users' guide. The following
+flags are available:
+
+EP93XXFB_PCLK_FALLING		Clock data on the falling edge of the
+				pixel clock. The default is to clock
+				data on the rising edge.
+
+EP93XXFB_SYNC_BLANK_HIGH	Blank signal is active high. By
+				default the blank signal is active low.
+
+EP93XXFB_SYNC_HORIZ_HIGH	Horizontal sync is active high. By
+				default the horizontal sync is active low.
+
+EP93XXFB_SYNC_VERT_HIGH		Vertical sync is active high. By
+				default the vertical sync is active high.
+
+The physical address of the framebuffer can be controlled using the
+following flags:
+
+EP93XXFB_USE_SDCSN0		Use SDCSn[0] for the framebuffer. This
+				is the default setting.
+
+EP93XXFB_USE_SDCSN1		Use SDCSn[1] for the framebuffer.
+
+EP93XXFB_USE_SDCSN2		Use SDCSn[2] for the framebuffer.
+
+EP93XXFB_USE_SDCSN3		Use SDCSn[3] for the framebuffer.
+
+==================
+Platform callbacks
+==================
+
+The EP93xx framebuffer driver supports three optional platform
+callbacks: setup, teardown and blank. The setup and teardown functions
+are called when the framebuffer driver is installed and removed
+respectively. The blank function is called whenever the display is
+blanked or unblanked.
+
+The setup and teardown devices pass the platform_device structure as
+an argument. The fb_info and ep93xxfb_mach_info structures can be
+obtained as follows:
+
+	static int some_board_fb_setup(struct platform_device *pdev)
+	{
+		struct ep93xxfb_mach_info *mach_info = pdev->dev.platform_data;
+		struct fb_info *fb_info = platform_get_drvdata(pdev);
+
+		/* Board specific framebuffer setup */
+	}
+
+======================
+Setting the video mode
+======================
+
+The video mode is set using the following syntax:
+
+	video=XRESxYRES[-BPP][@REFRESH]
+
+If the EP93xx video driver is built-in then the video mode is set on
+the Linux kernel command line, for example:
+
+	video=ep93xx-fb:800x600-16@60
+
+If the EP93xx video driver is built as a module then the video mode is
+set when the module is installed:
+
+	modprobe ep93xx-fb video=320x240
+
+==============
+Screenpage bug
+==============
+
+At least on the EP9315 there is a silicon bug which causes bit 27 of
+the VIDSCRNPAGE (framebuffer physical offset) to be tied low. There is
+an unofficial errata for this bug at:
+	http://marc.info/?l=linux-arm-kernel&m=110061245502000&w=2
+
+By default the EP93xx framebuffer driver checks if the allocated physical
+address has bit 27 set. If it does, then the memory is freed and an
+error is returned. The check can be disabled by adding the following
+option when loading the driver:
+
+      ep93xx-fb.check_screenpage_bug=0
+
+In some cases it may be possible to reconfigure your SDRAM layout to
+avoid this bug. See section 13 of the EP93xx users' guide for details.

drivers/video/Kconfig

@@ -2128,6 +2128,17 @@ config FB_MB862XX_LIME
 	---help---
 	  Framebuffer support for Fujitsu Lime GDC on host CPU bus.
 
+config FB_EP93XX
+	tristate "EP93XX frame buffer support"
+	depends on FB && ARCH_EP93XX
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
+	---help---
+	  Framebuffer driver for the Cirrus Logic EP93XX series of processors.
+	  This driver is also available as a module. The module will be called
+	  ep93xx-fb.
+
 config FB_PRE_INIT_FB
 	bool "Don't reinitialize, use bootloader's GDC/Display configuration"
 	depends on FB_MB862XX_LIME

drivers/video/Makefile

@@ -85,6 +85,7 @@ obj-$(CONFIG_FB_Q40)              += q40fb.o
 obj-$(CONFIG_FB_TGA)              += tgafb.o
 obj-$(CONFIG_FB_HP300)            += hpfb.o
 obj-$(CONFIG_FB_G364)             += g364fb.o
+obj-$(CONFIG_FB_EP93XX)		  += ep93xx-fb.o
 obj-$(CONFIG_FB_SA1100)           += sa1100fb.o
 obj-$(CONFIG_FB_HIT)              += hitfb.o
 obj-$(CONFIG_FB_EPSON1355)	  += epson1355fb.o

drivers/video/ep93xx-fb.c

+/*
+ * linux/drivers/video/ep93xx-fb.c
+ *
+ * Framebuffer support for the EP93xx series.
+ *
+ * Copyright (C) 2007 Bluewater Systems Ltd
+ * Author: Ryan Mallon <ryan@bluewatersys.com>
+ *
+ * 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/dma-mapping.h>
+#include <linux/clk.h>
+#include <linux/fb.h>
+
+#include <mach/fb.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:
+		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 __init 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 __init 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 offical 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\n",
+			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 __init ep93xxfb_probe(struct platform_device *pdev)
+{
+	struct ep93xxfb_mach_info *mach_info = pdev->dev.platform_data;
+	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;
+
+	err = ep93xxfb_alloc_videomem(info);
+	if (err)
+		goto failed;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		err = -ENXIO;
+		goto failed;
+	}
+
+	res = request_mem_region(res->start, resource_size(res), pdev->name);
+	if (!res) {
+		err = -EBUSY;
+		goto failed;
+	}
+
+	fbi->res = res;
+	fbi->mmio_base = ioremap(res->start, resource_size(res));
+	if (!fbi->mmio_base) {
+		err = -ENXIO;
+		goto failed;
+	}
+
+	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\n");
+		err = -EINVAL;
+		goto failed;
+	}
+
+	if (mach_info->setup) {
+		err = mach_info->setup(pdev);
+		if (err)
+			return err;
+	}
+
+	err = ep93xxfb_check_var(&info->var, info);
+	if (err)
+		goto failed;
+
+	fbi->clk = clk_get(info->dev, NULL);
+	if (IS_ERR(fbi->clk)) {
+		err = PTR_ERR(fbi->clk);
+		fbi->clk = NULL;
+		goto failed;
+	}
+
+	ep93xxfb_set_par(info);
+	clk_enable(fbi->clk);
+
+	err = register_framebuffer(info);
+	if (err)
+		goto failed;
+
+	dev_info(info->dev, "registered. Mode = %dx%d-%d\n",
+		 info->var.xres, info->var.yres, info->var.bits_per_pixel);
+	return 0;
+
+failed:
+	if (fbi->clk)
+		clk_put(fbi->clk);
+	if (fbi->mmio_base)
+		iounmap(fbi->mmio_base);
+	if (fbi->res)
+		release_mem_region(fbi->res->start, resource_size(fbi->res));
+	ep93xxfb_dealloc_videomem(info);
+	if (&info->cmap)
+		fb_dealloc_cmap(&info->cmap);
+	if (fbi->mach_info->teardown)
+		fbi->mach_info->teardown(pdev);
+	kfree(info);
+	platform_set_drvdata(pdev, NULL);
+
+	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);
+	clk_put(fbi->clk);
+	iounmap(fbi->mmio_base);
+	release_mem_region(fbi->res->start, resource_size(fbi->res));
+	ep93xxfb_dealloc_videomem(info);
+	fb_dealloc_cmap(&info->cmap);
+
+	if (fbi->mach_info->teardown)
+		fbi->mach_info->teardown(pdev);
+
+	kfree(info);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver ep93xxfb_driver = {
+	.probe		= ep93xxfb_probe,
+	.remove		= ep93xxfb_remove,
+	.driver = {
+		.name	= "ep93xx-fb",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __devinit ep93xxfb_init(void)
+{
+	return platform_driver_register(&ep93xxfb_driver);
+}
+
+static void __exit ep93xxfb_exit(void)
+{
+	platform_driver_unregister(&ep93xxfb_driver);
+}
+
+module_init(ep93xxfb_init);
+module_exit(ep93xxfb_exit);
+
+MODULE_DESCRIPTION("EP93XX Framebuffer Driver");
+MODULE_ALIAS("platform:ep93xx-fb");
+MODULE_AUTHOR("Ryan Mallon <ryan&bluewatersys.com>, "
+	      "H Hartley Sweeten <hsweeten@visionengravers.com");
+MODULE_LICENSE("GPL");