// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/video/cyber2000fb.c
 *
 *  Copyright (C) 1998-2002 Russell King
 *
 *  MIPS and 50xx clock support
 *  Copyright (C) 2001 Bradley D. LaRonde <brad@ltc.com>
 *
 *  32 bit support, text color and panning fixes for modes != 8 bit
 *  Copyright (C) 2002 Denis Oliver Kropp <dok@directfb.org>
 *
 * Integraphics CyberPro 2000, 2010 and 5000 frame buffer device
 *
 * Based on cyberfb.c.
 *
 * Note that we now use the new fbcon fix, var and cmap scheme.  We do
 * still have to check which console is the currently displayed one
 * however, especially for the colourmap stuff.
 *
 * We also use the new hotplug PCI subsystem.  I'm not sure if there
 * are any such cards, but I'm erring on the side of caution.  We don't
 * want to go pop just because someone does have one.
 *
 * Note that this doesn't work fully in the case of multiple CyberPro
 * cards with grabbers.  We currently can only attach to the first
 * CyberPro card found.
 *
 * When we're in truecolour mode, we power down the LUT RAM as a power
 * saving feature.  Also, when we enter any of the powersaving modes
 * (except soft blanking) we power down the RAMDACs.  This saves about
 * 1W, which is roughly 8% of the power consumption of a NetWinder
 * (which, incidentally, is about the same saving as a 2.5in hard disk
 * entering standby mode.)
 */
#include <linux/aperture.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>

#ifdef __arm__
#include <asm/mach-types.h>
#endif

#include "cyber2000fb.h"

struct cfb_info {
	struct fb_info		fb;
	struct display_switch	*dispsw;
	unsigned char		__iomem *region;
	unsigned char		__iomem *regs;
	u_int			id;
	u_int			irq;
	int			func_use_count;
	u_long			ref_ps;

	/*
	 * Clock divisors
	 */
	u_int			divisors[4];

	struct {
		u8 red, green, blue;
	} palette[NR_PALETTE];

	u_char			mem_ctl1;
	u_char			mem_ctl2;
	u_char			mclk_mult;
	u_char			mclk_div;
	/*
	 * RAMDAC control register is both of these or'ed together
	 */
	u_char			ramdac_ctrl;
	u_char			ramdac_powerdown;

	u32			pseudo_palette[16];

	spinlock_t		reg_b0_lock;

#ifdef CONFIG_FB_CYBER2000_DDC
	bool			ddc_registered;
	struct i2c_adapter	ddc_adapter;
	struct i2c_algo_bit_data	ddc_algo;
#endif

#ifdef CONFIG_FB_CYBER2000_I2C
	struct i2c_adapter	i2c_adapter;
	struct i2c_algo_bit_data i2c_algo;
#endif
};

static char *default_font = "Acorn8x8";
module_param(default_font, charp, 0);
MODULE_PARM_DESC(default_font, "Default font name");

/*
 * Our access methods.
 */
#define cyber2000fb_writel(val, reg, cfb)	writel(val, (cfb)->regs + (reg))
#define cyber2000fb_writew(val, reg, cfb)	writew(val, (cfb)->regs + (reg))
#define cyber2000fb_writeb(val, reg, cfb)	writeb(val, (cfb)->regs + (reg))

#define cyber2000fb_readb(reg, cfb)		readb((cfb)->regs + (reg))

static inline void
cyber2000_crtcw(unsigned int reg, unsigned int val, struct cfb_info *cfb)
{
	cyber2000fb_writew((reg & 255) | val << 8, 0x3d4, cfb);
}

static inline void
cyber2000_grphw(unsigned int reg, unsigned int val, struct cfb_info *cfb)
{
	cyber2000fb_writew((reg & 255) | val << 8, 0x3ce, cfb);
}

static inline unsigned int
cyber2000_grphr(unsigned int reg, struct cfb_info *cfb)
{
	cyber2000fb_writeb(reg, 0x3ce, cfb);
	return cyber2000fb_readb(0x3cf, cfb);
}

static inline void
cyber2000_attrw(unsigned int reg, unsigned int val, struct cfb_info *cfb)
{
	cyber2000fb_readb(0x3da, cfb);
	cyber2000fb_writeb(reg, 0x3c0, cfb);
	cyber2000fb_readb(0x3c1, cfb);
	cyber2000fb_writeb(val, 0x3c0, cfb);
}

static inline void
cyber2000_seqw(unsigned int reg, unsigned int val, struct cfb_info *cfb)
{
	cyber2000fb_writew((reg & 255) | val << 8, 0x3c4, cfb);
}

/* -------------------- Hardware specific routines ------------------------- */

/*
 * Hardware Cyber2000 Acceleration
 */
static void
cyber2000fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	unsigned long dst, col;

	if (!(cfb->fb.var.accel_flags & FB_ACCELF_TEXT)) {
		cfb_fillrect(info, rect);
		return;
	}

	cyber2000fb_writeb(0, CO_REG_CONTROL, cfb);
	cyber2000fb_writew(rect->width - 1, CO_REG_PIXWIDTH, cfb);
	cyber2000fb_writew(rect->height - 1, CO_REG_PIXHEIGHT, cfb);

	col = rect->color;
	if (cfb->fb.var.bits_per_pixel > 8)
		col = ((u32 *)cfb->fb.pseudo_palette)[col];
	cyber2000fb_writel(col, CO_REG_FGCOLOUR, cfb);

	dst = rect->dx + rect->dy * cfb->fb.var.xres_virtual;
	if (cfb->fb.var.bits_per_pixel == 24) {
		cyber2000fb_writeb(dst, CO_REG_X_PHASE, cfb);
		dst *= 3;
	}

	cyber2000fb_writel(dst, CO_REG_DEST_PTR, cfb);
	cyber2000fb_writeb(CO_FG_MIX_SRC, CO_REG_FGMIX, cfb);
	cyber2000fb_writew(CO_CMD_L_PATTERN_FGCOL, CO_REG_CMD_L, cfb);
	cyber2000fb_writew(CO_CMD_H_BLITTER, CO_REG_CMD_H, cfb);
}

static void
cyber2000fb_copyarea(struct fb_info *info, const struct fb_copyarea *region)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	unsigned int cmd = CO_CMD_L_PATTERN_FGCOL;
	unsigned long src, dst;

	if (!(cfb->fb.var.accel_flags & FB_ACCELF_TEXT)) {
		cfb_copyarea(info, region);
		return;
	}

	cyber2000fb_writeb(0, CO_REG_CONTROL, cfb);
	cyber2000fb_writew(region->width - 1, CO_REG_PIXWIDTH, cfb);
	cyber2000fb_writew(region->height - 1, CO_REG_PIXHEIGHT, cfb);

	src = region->sx + region->sy * cfb->fb.var.xres_virtual;
	dst = region->dx + region->dy * cfb->fb.var.xres_virtual;

	if (region->sx < region->dx) {
		src += region->width - 1;
		dst += region->width - 1;
		cmd |= CO_CMD_L_INC_LEFT;
	}

	if (region->sy < region->dy) {
		src += (region->height - 1) * cfb->fb.var.xres_virtual;
		dst += (region->height - 1) * cfb->fb.var.xres_virtual;
		cmd |= CO_CMD_L_INC_UP;
	}

	if (cfb->fb.var.bits_per_pixel == 24) {
		cyber2000fb_writeb(dst, CO_REG_X_PHASE, cfb);
		src *= 3;
		dst *= 3;
	}
	cyber2000fb_writel(src, CO_REG_SRC1_PTR, cfb);
	cyber2000fb_writel(dst, CO_REG_DEST_PTR, cfb);
	cyber2000fb_writew(CO_FG_MIX_SRC, CO_REG_FGMIX, cfb);
	cyber2000fb_writew(cmd, CO_REG_CMD_L, cfb);
	cyber2000fb_writew(CO_CMD_H_FGSRCMAP | CO_CMD_H_BLITTER,
			   CO_REG_CMD_H, cfb);
}

static int cyber2000fb_sync(struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	int count = 100000;

	if (!(cfb->fb.var.accel_flags & FB_ACCELF_TEXT))
		return 0;

	while (cyber2000fb_readb(CO_REG_CONTROL, cfb) & CO_CTRL_BUSY) {
		if (!count--) {
			debug_printf("accel_wait timed out\n");
			cyber2000fb_writeb(0, CO_REG_CONTROL, cfb);
			break;
		}
		udelay(1);
	}
	return 0;
}

/*
 * ===========================================================================
 */

static inline u32 convert_bitfield(u_int val, struct fb_bitfield *bf)
{
	u_int mask = (1 << bf->length) - 1;

	return (val >> (16 - bf->length) & mask) << bf->offset;
}

/*
 *    Set a single color register. Return != 0 for invalid regno.
 */
static int
cyber2000fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
		      u_int transp, struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	struct fb_var_screeninfo *var = &cfb->fb.var;
	u32 pseudo_val;
	int ret = 1;

	switch (cfb->fb.fix.visual) {
	default:
		return 1;

	/*
	 * Pseudocolour:
	 *	   8     8
	 * pixel --/--+--/-->  red lut  --> red dac
	 *	      |  8
	 *	      +--/--> green lut --> green dac
	 *	      |  8
	 *	      +--/-->  blue lut --> blue dac
	 */
	case FB_VISUAL_PSEUDOCOLOR:
		if (regno >= NR_PALETTE)
			return 1;

		red >>= 8;
		green >>= 8;
		blue >>= 8;

		cfb->palette[regno].red = red;
		cfb->palette[regno].green = green;
		cfb->palette[regno].blue = blue;

		cyber2000fb_writeb(regno, 0x3c8, cfb);
		cyber2000fb_writeb(red, 0x3c9, cfb);
		cyber2000fb_writeb(green, 0x3c9, cfb);
		cyber2000fb_writeb(blue, 0x3c9, cfb);
		return 0;

	/*
	 * Direct colour:
	 *	   n     rl
	 * pixel --/--+--/-->  red lut  --> red dac
	 *	      |  gl
	 *	      +--/--> green lut --> green dac
	 *	      |  bl
	 *	      +--/-->  blue lut --> blue dac
	 * n = bpp, rl = red length, gl = green length, bl = blue length
	 */
	case FB_VISUAL_DIRECTCOLOR:
		red >>= 8;
		green >>= 8;
		blue >>= 8;

		if (var->green.length == 6 && regno < 64) {
			cfb->palette[regno << 2].green = green;

			/*
			 * The 6 bits of the green component are applied
			 * to the high 6 bits of the LUT.
			 */
			cyber2000fb_writeb(regno << 2, 0x3c8, cfb);
			cyber2000fb_writeb(cfb->palette[regno >> 1].red,
					   0x3c9, cfb);
			cyber2000fb_writeb(green, 0x3c9, cfb);
			cyber2000fb_writeb(cfb->palette[regno >> 1].blue,
					   0x3c9, cfb);

			green = cfb->palette[regno << 3].green;

			ret = 0;
		}

		if (var->green.length >= 5 && regno < 32) {
			cfb->palette[regno << 3].red = red;
			cfb->palette[regno << 3].green = green;
			cfb->palette[regno << 3].blue = blue;

			/*
			 * The 5 bits of each colour component are
			 * applied to the high 5 bits of the LUT.
			 */
			cyber2000fb_writeb(regno << 3, 0x3c8, cfb);
			cyber2000fb_writeb(red, 0x3c9, cfb);
			cyber2000fb_writeb(green, 0x3c9, cfb);
			cyber2000fb_writeb(blue, 0x3c9, cfb);
			ret = 0;
		}

		if (var->green.length == 4 && regno < 16) {
			cfb->palette[regno << 4].red = red;
			cfb->palette[regno << 4].green = green;
			cfb->palette[regno << 4].blue = blue;

			/*
			 * The 5 bits of each colour component are
			 * applied to the high 5 bits of the LUT.
			 */
			cyber2000fb_writeb(regno << 4, 0x3c8, cfb);
			cyber2000fb_writeb(red, 0x3c9, cfb);
			cyber2000fb_writeb(green, 0x3c9, cfb);
			cyber2000fb_writeb(blue, 0x3c9, cfb);
			ret = 0;
		}

		/*
		 * Since this is only used for the first 16 colours, we
		 * don't have to care about overflowing for regno >= 32
		 */
		pseudo_val = regno << var->red.offset |
			     regno << var->green.offset |
			     regno << var->blue.offset;
		break;

	/*
	 * True colour:
	 *	   n     rl
	 * pixel --/--+--/--> red dac
	 *	      |  gl
	 *	      +--/--> green dac
	 *	      |  bl
	 *	      +--/--> blue dac
	 * n = bpp, rl = red length, gl = green length, bl = blue length
	 */
	case FB_VISUAL_TRUECOLOR:
		pseudo_val = convert_bitfield(transp ^ 0xffff, &var->transp);
		pseudo_val |= convert_bitfield(red, &var->red);
		pseudo_val |= convert_bitfield(green, &var->green);
		pseudo_val |= convert_bitfield(blue, &var->blue);
		ret = 0;
		break;
	}

	/*
	 * Now set our pseudo palette for the CFB16/24/32 drivers.
	 */
	if (regno < 16)
		((u32 *)cfb->fb.pseudo_palette)[regno] = pseudo_val;

	return ret;
}

struct par_info {
	/*
	 * Hardware
	 */
	u_char	clock_mult;
	u_char	clock_div;
	u_char	extseqmisc;
	u_char	co_pixfmt;
	u_char	crtc_ofl;
	u_char	crtc[19];
	u_int	width;
	u_int	pitch;
	u_int	fetch;

	/*
	 * Other
	 */
	u_char	ramdac;
};

static const u_char crtc_idx[] = {
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
	0x08, 0x09,
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18
};

static void cyber2000fb_write_ramdac_ctrl(struct cfb_info *cfb)
{
	unsigned int i;
	unsigned int val = cfb->ramdac_ctrl | cfb->ramdac_powerdown;

	cyber2000fb_writeb(0x56, 0x3ce, cfb);
	i = cyber2000fb_readb(0x3cf, cfb);
	cyber2000fb_writeb(i | 4, 0x3cf, cfb);
	cyber2000fb_writeb(val, 0x3c6, cfb);
	cyber2000fb_writeb(i, 0x3cf, cfb);
	/* prevent card lock-up observed on x86 with CyberPro 2000 */
	cyber2000fb_readb(0x3cf, cfb);
}

static void cyber2000fb_set_timing(struct cfb_info *cfb, struct par_info *hw)
{
	u_int i;

	/*
	 * Blank palette
	 */
	for (i = 0; i < NR_PALETTE; i++) {
		cyber2000fb_writeb(i, 0x3c8, cfb);
		cyber2000fb_writeb(0, 0x3c9, cfb);
		cyber2000fb_writeb(0, 0x3c9, cfb);
		cyber2000fb_writeb(0, 0x3c9, cfb);
	}

	cyber2000fb_writeb(0xef, 0x3c2, cfb);
	cyber2000_crtcw(0x11, 0x0b, cfb);
	cyber2000_attrw(0x11, 0x00, cfb);

	cyber2000_seqw(0x00, 0x01, cfb);
	cyber2000_seqw(0x01, 0x01, cfb);
	cyber2000_seqw(0x02, 0x0f, cfb);
	cyber2000_seqw(0x03, 0x00, cfb);
	cyber2000_seqw(0x04, 0x0e, cfb);
	cyber2000_seqw(0x00, 0x03, cfb);

	for (i = 0; i < sizeof(crtc_idx); i++)
		cyber2000_crtcw(crtc_idx[i], hw->crtc[i], cfb);

	for (i = 0x0a; i < 0x10; i++)
		cyber2000_crtcw(i, 0, cfb);

	cyber2000_grphw(EXT_CRT_VRTOFL, hw->crtc_ofl, cfb);
	cyber2000_grphw(0x00, 0x00, cfb);
	cyber2000_grphw(0x01, 0x00, cfb);
	cyber2000_grphw(0x02, 0x00, cfb);
	cyber2000_grphw(0x03, 0x00, cfb);
	cyber2000_grphw(0x04, 0x00, cfb);
	cyber2000_grphw(0x05, 0x60, cfb);
	cyber2000_grphw(0x06, 0x05, cfb);
	cyber2000_grphw(0x07, 0x0f, cfb);
	cyber2000_grphw(0x08, 0xff, cfb);

	/* Attribute controller registers */
	for (i = 0; i < 16; i++)
		cyber2000_attrw(i, i, cfb);

	cyber2000_attrw(0x10, 0x01, cfb);
	cyber2000_attrw(0x11, 0x00, cfb);
	cyber2000_attrw(0x12, 0x0f, cfb);
	cyber2000_attrw(0x13, 0x00, cfb);
	cyber2000_attrw(0x14, 0x00, cfb);

	/* PLL registers */
	spin_lock(&cfb->reg_b0_lock);
	cyber2000_grphw(EXT_DCLK_MULT, hw->clock_mult, cfb);
	cyber2000_grphw(EXT_DCLK_DIV, hw->clock_div, cfb);
	cyber2000_grphw(EXT_MCLK_MULT, cfb->mclk_mult, cfb);
	cyber2000_grphw(EXT_MCLK_DIV, cfb->mclk_div, cfb);
	cyber2000_grphw(0x90, 0x01, cfb);
	cyber2000_grphw(0xb9, 0x80, cfb);
	cyber2000_grphw(0xb9, 0x00, cfb);
	spin_unlock(&cfb->reg_b0_lock);

	cfb->ramdac_ctrl = hw->ramdac;
	cyber2000fb_write_ramdac_ctrl(cfb);

	cyber2000fb_writeb(0x20, 0x3c0, cfb);
	cyber2000fb_writeb(0xff, 0x3c6, cfb);

	cyber2000_grphw(0x14, hw->fetch, cfb);
	cyber2000_grphw(0x15, ((hw->fetch >> 8) & 0x03) |
			      ((hw->pitch >> 4) & 0x30), cfb);
	cyber2000_grphw(EXT_SEQ_MISC, hw->extseqmisc, cfb);

	/*
	 * Set up accelerator registers
	 */
	cyber2000fb_writew(hw->width, CO_REG_SRC_WIDTH, cfb);
	cyber2000fb_writew(hw->width, CO_REG_DEST_WIDTH, cfb);
	cyber2000fb_writeb(hw->co_pixfmt, CO_REG_PIXFMT, cfb);
}

static inline int
cyber2000fb_update_start(struct cfb_info *cfb, struct fb_var_screeninfo *var)
{
	u_int base = var->yoffset * var->xres_virtual + var->xoffset;

	base *= var->bits_per_pixel;

	/*
	 * Convert to bytes and shift two extra bits because DAC
	 * can only start on 4 byte aligned data.
	 */
	base >>= 5;

	if (base >= 1 << 20)
		return -EINVAL;

	cyber2000_grphw(0x10, base >> 16 | 0x10, cfb);
	cyber2000_crtcw(0x0c, base >> 8, cfb);
	cyber2000_crtcw(0x0d, base, cfb);

	return 0;
}

static int
cyber2000fb_decode_crtc(struct par_info *hw, struct cfb_info *cfb,
			struct fb_var_screeninfo *var)
{
	u_int Htotal, Hblankend, Hsyncend;
	u_int Vtotal, Vdispend, Vblankstart, Vblankend, Vsyncstart, Vsyncend;
#define ENCODE_BIT(v, b1, m, b2) ((((v) >> (b1)) & (m)) << (b2))

	hw->crtc[13] = hw->pitch;
	hw->crtc[17] = 0xe3;
	hw->crtc[14] = 0;
	hw->crtc[8]  = 0;

	Htotal     = var->xres + var->right_margin +
		     var->hsync_len + var->left_margin;

	if (Htotal > 2080)
		return -EINVAL;

	hw->crtc[0] = (Htotal >> 3) - 5;
	hw->crtc[1] = (var->xres >> 3) - 1;
	hw->crtc[2] = var->xres >> 3;
	hw->crtc[4] = (var->xres + var->right_margin) >> 3;

	Hblankend   = (Htotal - 4 * 8) >> 3;

	hw->crtc[3] = ENCODE_BIT(Hblankend,  0, 0x1f,  0) |
		      ENCODE_BIT(1,          0, 0x01,  7);

	Hsyncend    = (var->xres + var->right_margin + var->hsync_len) >> 3;

	hw->crtc[5] = ENCODE_BIT(Hsyncend,   0, 0x1f,  0) |
		      ENCODE_BIT(Hblankend,  5, 0x01,  7);

	Vdispend    = var->yres - 1;
	Vsyncstart  = var->yres + var->lower_margin;
	Vsyncend    = var->yres + var->lower_margin + var->vsync_len;
	Vtotal      = var->yres + var->lower_margin + var->vsync_len +
		      var->upper_margin - 2;

	if (Vtotal > 2047)
		return -EINVAL;

	Vblankstart = var->yres + 6;
	Vblankend   = Vtotal - 10;

	hw->crtc[6]  = Vtotal;
	hw->crtc[7]  = ENCODE_BIT(Vtotal,     8, 0x01,  0) |
			ENCODE_BIT(Vdispend,   8, 0x01,  1) |
			ENCODE_BIT(Vsyncstart, 8, 0x01,  2) |
			ENCODE_BIT(Vblankstart, 8, 0x01,  3) |
			ENCODE_BIT(1,          0, 0x01,  4) |
			ENCODE_BIT(Vtotal,     9, 0x01,  5) |
			ENCODE_BIT(Vdispend,   9, 0x01,  6) |
			ENCODE_BIT(Vsyncstart, 9, 0x01,  7);
	hw->crtc[9]  = ENCODE_BIT(0,          0, 0x1f,  0) |
			ENCODE_BIT(Vblankstart, 9, 0x01,  5) |
			ENCODE_BIT(1,          0, 0x01,  6);
	hw->crtc[10] = Vsyncstart;
	hw->crtc[11] = ENCODE_BIT(Vsyncend,   0, 0x0f,  0) |
		       ENCODE_BIT(1,          0, 0x01,  7);
	hw->crtc[12] = Vdispend;
	hw->crtc[15] = Vblankstart;
	hw->crtc[16] = Vblankend;
	hw->crtc[18] = 0xff;

	/*
	 * overflow - graphics reg 0x11
	 * 0=VTOTAL:10 1=VDEND:10 2=VRSTART:10 3=VBSTART:10
	 * 4=LINECOMP:10 5-IVIDEO 6=FIXCNT
	 */
	hw->crtc_ofl =
		ENCODE_BIT(Vtotal, 10, 0x01, 0) |
		ENCODE_BIT(Vdispend, 10, 0x01, 1) |
		ENCODE_BIT(Vsyncstart, 10, 0x01, 2) |
		ENCODE_BIT(Vblankstart, 10, 0x01, 3) |
		EXT_CRT_VRTOFL_LINECOMP10;

	/* woody: set the interlaced bit... */
	/* FIXME: what about doublescan? */
	if ((var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED)
		hw->crtc_ofl |= EXT_CRT_VRTOFL_INTERLACE;

	return 0;
}

/*
 * The following was discovered by a good monitor, bit twiddling, theorising
 * and but mostly luck.  Strangely, it looks like everyone elses' PLL!
 *
 * Clock registers:
 *   fclock = fpll / div2
 *   fpll   = fref * mult / div1
 * where:
 *   fref = 14.318MHz (69842ps)
 *   mult = reg0xb0.7:0
 *   div1 = (reg0xb1.5:0 + 1)
 *   div2 =  2^(reg0xb1.7:6)
 *   fpll should be between 115 and 260 MHz
 *  (8696ps and 3846ps)
 */
static int
cyber2000fb_decode_clock(struct par_info *hw, struct cfb_info *cfb,
			 struct fb_var_screeninfo *var)
{
	u_long pll_ps = var->pixclock;
	const u_long ref_ps = cfb->ref_ps;
	u_int div2, t_div1, best_div1, best_mult;
	int best_diff;
	int vco;

	/*
	 * Step 1:
	 *   find div2 such that 115MHz < fpll < 260MHz
	 *   and 0 <= div2 < 4
	 */
	for (div2 = 0; div2 < 4; div2++) {
		u_long new_pll;

		new_pll = pll_ps / cfb->divisors[div2];
		if (8696 > new_pll && new_pll > 3846) {
			pll_ps = new_pll;
			break;
		}
	}

	if (div2 == 4)
		return -EINVAL;

	/*
	 * Step 2:
	 *  Given pll_ps and ref_ps, find:
	 *    pll_ps * 0.995 < pll_ps_calc < pll_ps * 1.005
	 *  where { 1 < best_div1 < 32, 1 < best_mult < 256 }
	 *    pll_ps_calc = best_div1 / (ref_ps * best_mult)
	 */
	best_diff = 0x7fffffff;
	best_mult = 2;
	best_div1 = 32;
	for (t_div1 = 2; t_div1 < 32; t_div1 += 1) {
		u_int rr, t_mult, t_pll_ps;
		int diff;

		/*
		 * Find the multiplier for this divisor
		 */
		rr = ref_ps * t_div1;
		t_mult = (rr + pll_ps / 2) / pll_ps;

		/*
		 * Is the multiplier within the correct range?
		 */
		if (t_mult > 256 || t_mult < 2)
			continue;

		/*
		 * Calculate the actual clock period from this multiplier
		 * and divisor, and estimate the error.
		 */
		t_pll_ps = (rr + t_mult / 2) / t_mult;
		diff = pll_ps - t_pll_ps;
		if (diff < 0)
			diff = -diff;

		if (diff < best_diff) {
			best_diff = diff;
			best_mult = t_mult;
			best_div1 = t_div1;
		}

		/*
		 * If we hit an exact value, there is no point in continuing.
		 */
		if (diff == 0)
			break;
	}

	/*
	 * Step 3:
	 *  combine values
	 */
	hw->clock_mult = best_mult - 1;
	hw->clock_div  = div2 << 6 | (best_div1 - 1);

	vco = ref_ps * best_div1 / best_mult;
	if ((ref_ps == 40690) && (vco < 5556))
		/* Set VFSEL when VCO > 180MHz (5.556 ps). */
		hw->clock_div |= EXT_DCLK_DIV_VFSEL;

	return 0;
}

/*
 *    Set the User Defined Part of the Display
 */
static int
cyber2000fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	struct par_info hw;
	unsigned int mem;
	int err;

	var->transp.msb_right	= 0;
	var->red.msb_right	= 0;
	var->green.msb_right	= 0;
	var->blue.msb_right	= 0;
	var->transp.offset	= 0;
	var->transp.length	= 0;

	switch (var->bits_per_pixel) {
	case 8:	/* PSEUDOCOLOUR, 256 */
		var->red.offset		= 0;
		var->red.length		= 8;
		var->green.offset	= 0;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;
		break;

	case 16:/* DIRECTCOLOUR, 64k or 32k */
		switch (var->green.length) {
		case 6: /* RGB565, 64k */
			var->red.offset		= 11;
			var->red.length		= 5;
			var->green.offset	= 5;
			var->green.length	= 6;
			var->blue.offset	= 0;
			var->blue.length	= 5;
			break;

		default:
		case 5: /* RGB555, 32k */
			var->red.offset		= 10;
			var->red.length		= 5;
			var->green.offset	= 5;
			var->green.length	= 5;
			var->blue.offset	= 0;
			var->blue.length	= 5;
			break;

		case 4: /* RGB444, 4k + transparency? */
			var->transp.offset	= 12;
			var->transp.length	= 4;
			var->red.offset		= 8;
			var->red.length		= 4;
			var->green.offset	= 4;
			var->green.length	= 4;
			var->blue.offset	= 0;
			var->blue.length	= 4;
			break;
		}
		break;

	case 24:/* TRUECOLOUR, 16m */
		var->red.offset		= 16;
		var->red.length		= 8;
		var->green.offset	= 8;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;
		break;

	case 32:/* TRUECOLOUR, 16m */
		var->transp.offset	= 24;
		var->transp.length	= 8;
		var->red.offset		= 16;
		var->red.length		= 8;
		var->green.offset	= 8;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;
		break;

	default:
		return -EINVAL;
	}

	mem = var->xres_virtual * var->yres_virtual * (var->bits_per_pixel / 8);
	if (mem > cfb->fb.fix.smem_len)
		var->yres_virtual = cfb->fb.fix.smem_len * 8 /
				    (var->bits_per_pixel * var->xres_virtual);

	if (var->yres > var->yres_virtual)
		var->yres = var->yres_virtual;
	if (var->xres > var->xres_virtual)
		var->xres = var->xres_virtual;

	err = cyber2000fb_decode_clock(&hw, cfb, var);
	if (err)
		return err;

	err = cyber2000fb_decode_crtc(&hw, cfb, var);
	if (err)
		return err;

	return 0;
}

static int cyber2000fb_set_par(struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	struct fb_var_screeninfo *var = &cfb->fb.var;
	struct par_info hw;
	unsigned int mem;

	hw.width = var->xres_virtual;
	hw.ramdac = RAMDAC_VREFEN | RAMDAC_DAC8BIT;

	switch (var->bits_per_pixel) {
	case 8:
		hw.co_pixfmt		= CO_PIXFMT_8BPP;
		hw.pitch		= hw.width >> 3;
		hw.extseqmisc		= EXT_SEQ_MISC_8;
		break;

	case 16:
		hw.co_pixfmt		= CO_PIXFMT_16BPP;
		hw.pitch		= hw.width >> 2;

		switch (var->green.length) {
		case 6: /* RGB565, 64k */
			hw.extseqmisc	= EXT_SEQ_MISC_16_RGB565;
			break;
		case 5: /* RGB555, 32k */
			hw.extseqmisc	= EXT_SEQ_MISC_16_RGB555;
			break;
		case 4: /* RGB444, 4k + transparency? */
			hw.extseqmisc	= EXT_SEQ_MISC_16_RGB444;
			break;
		default:
			BUG();
		}
		break;

	case 24:/* TRUECOLOUR, 16m */
		hw.co_pixfmt		= CO_PIXFMT_24BPP;
		hw.width		*= 3;
		hw.pitch		= hw.width >> 3;
		hw.ramdac		|= (RAMDAC_BYPASS | RAMDAC_RAMPWRDN);
		hw.extseqmisc		= EXT_SEQ_MISC_24_RGB888;
		break;

	case 32:/* TRUECOLOUR, 16m */
		hw.co_pixfmt		= CO_PIXFMT_32BPP;
		hw.pitch		= hw.width >> 1;
		hw.ramdac		|= (RAMDAC_BYPASS | RAMDAC_RAMPWRDN);
		hw.extseqmisc		= EXT_SEQ_MISC_32;
		break;

	default:
		BUG();
	}

	/*
	 * Sigh, this is absolutely disgusting, but caused by
	 * the way the fbcon developers want to separate out
	 * the "checking" and the "setting" of the video mode.
	 *
	 * If the mode is not suitable for the hardware here,
	 * we can't prevent it being set by returning an error.
	 *
	 * In theory, since NetWinders contain just one VGA card,
	 * we should never end up hitting this problem.
	 */
	BUG_ON(cyber2000fb_decode_clock(&hw, cfb, var) != 0);
	BUG_ON(cyber2000fb_decode_crtc(&hw, cfb, var) != 0);

	hw.width -= 1;
	hw.fetch = hw.pitch;
	if (!(cfb->mem_ctl2 & MEM_CTL2_64BIT))
		hw.fetch <<= 1;
	hw.fetch += 1;

	cfb->fb.fix.line_length = var->xres_virtual * var->bits_per_pixel / 8;

	/*
	 * Same here - if the size of the video mode exceeds the
	 * available RAM, we can't prevent this mode being set.
	 *
	 * In theory, since NetWinders contain just one VGA card,
	 * we should never end up hitting this problem.
	 */
	mem = cfb->fb.fix.line_length * var->yres_virtual;
	BUG_ON(mem > cfb->fb.fix.smem_len);

	/*
	 * 8bpp displays are always pseudo colour.  16bpp and above
	 * are direct colour or true colour, depending on whether
	 * the RAMDAC palettes are bypassed.  (Direct colour has
	 * palettes, true colour does not.)
	 */
	if (var->bits_per_pixel == 8)
		cfb->fb.fix.visual = FB_VISUAL_PSEUDOCOLOR;
	else if (hw.ramdac & RAMDAC_BYPASS)
		cfb->fb.fix.visual = FB_VISUAL_TRUECOLOR;
	else
		cfb->fb.fix.visual = FB_VISUAL_DIRECTCOLOR;

	cyber2000fb_set_timing(cfb, &hw);
	cyber2000fb_update_start(cfb, var);

	return 0;
}

/*
 *    Pan or Wrap the Display
 */
static int
cyber2000fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);

	if (cyber2000fb_update_start(cfb, var))
		return -EINVAL;

	cfb->fb.var.xoffset = var->xoffset;
	cfb->fb.var.yoffset = var->yoffset;

	if (var->vmode & FB_VMODE_YWRAP) {
		cfb->fb.var.vmode |= FB_VMODE_YWRAP;
	} else {
		cfb->fb.var.vmode &= ~FB_VMODE_YWRAP;
	}

	return 0;
}

/*
 *    (Un)Blank the display.
 *
 *  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
 *
 *  wms...Enable VESA DMPS compatible powerdown mode
 *  run "setterm -powersave powerdown" to take advantage
 */
static int cyber2000fb_blank(int blank, struct fb_info *info)
{
	struct cfb_info *cfb = container_of(info, struct cfb_info, fb);
	unsigned int sync = 0;
	int i;

	switch (blank) {
	case FB_BLANK_POWERDOWN:	/* powerdown - both sync lines down */
		sync = EXT_SYNC_CTL_VS_0 | EXT_SYNC_CTL_HS_0;
		break;
	case FB_BLANK_HSYNC_SUSPEND:	/* hsync off */
		sync = EXT_SYNC_CTL_VS_NORMAL | EXT_SYNC_CTL_HS_0;
		break;
	case FB_BLANK_VSYNC_SUSPEND:	/* vsync off */
		sync = EXT_SYNC_CTL_VS_0 | EXT_SYNC_CTL_HS_NORMAL;
		break;
	case FB_BLANK_NORMAL:		/* soft blank */
	default:			/* unblank */
		break;
	}

	cyber2000_grphw(EXT_SYNC_CTL, sync, cfb);

	if (blank <= 1) {
		/* turn on ramdacs */
		cfb->ramdac_powerdown &= ~(RAMDAC_DACPWRDN | RAMDAC_BYPASS |
					   RAMDAC_RAMPWRDN);
		cyber2000fb_write_ramdac_ctrl(cfb);
	}

	/*
	 * Soft blank/unblank the display.
	 */
	if (blank) {	/* soft blank */
		for (i = 0; i < NR_PALETTE; i++) {
			cyber2000fb_writeb(i, 0x3c8, cfb);
			cyber2000fb_writeb(0, 0x3c9, cfb);
			cyber2000fb_writeb(0, 0x3c9, cfb);
			cyber2000fb_writeb(0, 0x3c9, cfb);
		}
	} else {	/* unblank */
		for (i = 0; i < NR_PALETTE; i++) {
			cyber2000fb_writeb(i, 0x3c8, cfb);
			cyber2000fb_writeb(cfb->palette[i].red, 0x3c9, cfb);
			cyber2000fb_writeb(cfb->palette[i].green, 0x3c9, cfb);
			cyber2000fb_writeb(cfb->palette[i].blue, 0x3c9, cfb);
		}
	}

	if (blank >= 2) {
		/* turn off ramdacs */
		cfb->ramdac_powerdown |= RAMDAC_DACPWRDN | RAMDAC_BYPASS |
					 RAMDAC_RAMPWRDN;
		cyber2000fb_write_ramdac_ctrl(cfb);
	}

	return 0;
}

static const struct fb_ops cyber2000fb_ops = {
	.owner		= THIS_MODULE,
	__FB_DEFAULT_IOMEM_OPS_RDWR,
	.fb_check_var	= cyber2000fb_check_var,
	.fb_set_par	= cyber2000fb_set_par,
	.fb_setcolreg	= cyber2000fb_setcolreg,
	.fb_blank	= cyber2000fb_blank,
	.fb_pan_display	= cyber2000fb_pan_display,
	.fb_fillrect	= cyber2000fb_fillrect,
	.fb_copyarea	= cyber2000fb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_sync	= cyber2000fb_sync,
	__FB_DEFAULT_IOMEM_OPS_MMAP,
};

/*
 * This is the only "static" reference to the internal data structures
 * of this driver.  It is here solely at the moment to support the other
 * CyberPro modules external to this driver.
 */
static struct cfb_info *int_cfb_info;

/*
 * Enable access to the extended registers
 */
void cyber2000fb_enable_extregs(struct cfb_info *cfb)
{
	cfb->func_use_count += 1;

	if (cfb->func_use_count == 1) {
		int old;

		old = cyber2000_grphr(EXT_FUNC_CTL, cfb);
		old |= EXT_FUNC_CTL_EXTREGENBL;
		cyber2000_grphw(EXT_FUNC_CTL, old, cfb);
	}
}

/*
 * Disable access to the extended registers
 */
void cyber2000fb_disable_extregs(struct cfb_info *cfb)
{
	if (cfb->func_use_count == 1) {
		int old;

		old = cyber2000_grphr(EXT_FUNC_CTL, cfb);
		old &= ~EXT_FUNC_CTL_EXTREGENBL;
		cyber2000_grphw(EXT_FUNC_CTL, old, cfb);
	}

	if (cfb->func_use_count == 0)
		printk(KERN_ERR "disable_extregs: count = 0\n");
	else
		cfb->func_use_count -= 1;
}

#ifdef CONFIG_FB_CYBER2000_DDC

#define DDC_REG		0xb0
#define DDC_SCL_OUT	(1 << 0)
#define DDC_SDA_OUT	(1 << 4)
#define DDC_SCL_IN	(1 << 2)
#define DDC_SDA_IN	(1 << 6)

static void cyber2000fb_enable_ddc(struct cfb_info *cfb)
	__acquires(&cfb->reg_b0_lock)
{
	spin_lock(&cfb->reg_b0_lock);
	cyber2000fb_writew(0x1bf, 0x3ce, cfb);
}

static void cyber2000fb_disable_ddc(struct cfb_info *cfb)
	__releases(&cfb->reg_b0_lock)
{
	cyber2000fb_writew(0x0bf, 0x3ce, cfb);
	spin_unlock(&cfb->reg_b0_lock);
}


static void cyber2000fb_ddc_setscl(void *data, int val)
{
	struct cfb_info *cfb = data;
	unsigned char reg;

	cyber2000fb_enable_ddc(cfb);
	reg = cyber2000_grphr(DDC_REG, cfb);
	if (!val)	/* bit is inverted */
		reg |= DDC_SCL_OUT;
	else
		reg &= ~DDC_SCL_OUT;
	cyber2000_grphw(DDC_REG, reg, cfb);
	cyber2000fb_disable_ddc(cfb);
}

static void cyber2000fb_ddc_setsda(void *data, int val)
{
	struct cfb_info *cfb = data;
	unsigned char reg;

	cyber2000fb_enable_ddc(cfb);
	reg = cyber2000_grphr(DDC_REG, cfb);
	if (!val)	/* bit is inverted */
		reg |= DDC_SDA_OUT;
	else
		reg &= ~DDC_SDA_OUT;
	cyber2000_grphw(DDC_REG, reg, cfb);
	cyber2000fb_disable_ddc(cfb);
}

static int cyber2000fb_ddc_getscl(void *data)
{
	struct cfb_info *cfb = data;
	int retval;

	cyber2000fb_enable_ddc(cfb);
	retval = !!(cyber2000_grphr(DDC_REG, cfb) & DDC_SCL_IN);
	cyber2000fb_disable_ddc(cfb);

	return retval;
}

static int cyber2000fb_ddc_getsda(void *data)
{
	struct cfb_info *cfb = data;
	int retval;

	cyber2000fb_enable_ddc(cfb);
	retval = !!(cyber2000_grphr(DDC_REG, cfb) & DDC_SDA_IN);
	cyber2000fb_disable_ddc(cfb);

	return retval;
}

static int cyber2000fb_setup_ddc_bus(struct cfb_info *cfb)
{
	strscpy(cfb->ddc_adapter.name, cfb->fb.fix.id,
		sizeof(cfb->ddc_adapter.name));
	cfb->ddc_adapter.owner		= THIS_MODULE;
	cfb->ddc_adapter.algo_data	= &cfb->ddc_algo;
	cfb->ddc_adapter.dev.parent	= cfb->fb.device;
	cfb->ddc_algo.setsda		= cyber2000fb_ddc_setsda;
	cfb->ddc_algo.setscl		= cyber2000fb_ddc_setscl;
	cfb->ddc_algo.getsda		= cyber2000fb_ddc_getsda;
	cfb->ddc_algo.getscl		= cyber2000fb_ddc_getscl;
	cfb->ddc_algo.udelay		= 10;
	cfb->ddc_algo.timeout		= 20;
	cfb->ddc_algo.data		= cfb;

	i2c_set_adapdata(&cfb->ddc_adapter, cfb);

	return i2c_bit_add_bus(&cfb->ddc_adapter);
}
#endif /* CONFIG_FB_CYBER2000_DDC */

#ifdef CONFIG_FB_CYBER2000_I2C
static void cyber2000fb_i2c_setsda(void *data, int state)
{
	struct cfb_info *cfb = data;
	unsigned int latch2;

	spin_lock(&cfb->reg_b0_lock);
	latch2 = cyber2000_grphr(EXT_LATCH2, cfb);
	latch2 &= EXT_LATCH2_I2C_CLKEN;
	if (state)
		latch2 |= EXT_LATCH2_I2C_DATEN;
	cyber2000_grphw(EXT_LATCH2, latch2, cfb);
	spin_unlock(&cfb->reg_b0_lock);
}

static void cyber2000fb_i2c_setscl(void *data, int state)
{
	struct cfb_info *cfb = data;
	unsigned int latch2;

	spin_lock(&cfb->reg_b0_lock);
	latch2 = cyber2000_grphr(EXT_LATCH2, cfb);
	latch2 &= EXT_LATCH2_I2C_DATEN;
	if (state)
		latch2 |= EXT_LATCH2_I2C_CLKEN;
	cyber2000_grphw(EXT_LATCH2, latch2, cfb);
	spin_unlock(&cfb->reg_b0_lock);
}

static int cyber2000fb_i2c_getsda(void *data)
{
	struct cfb_info *cfb = data;
	int ret;

	spin_lock(&cfb->reg_b0_lock);
	ret = !!(cyber2000_grphr(EXT_LATCH2, cfb) & EXT_LATCH2_I2C_DAT);
	spin_unlock(&cfb->reg_b0_lock);

	return ret;
}

static int cyber2000fb_i2c_getscl(void *data)
{
	struct cfb_info *cfb = data;
	int ret;

	spin_lock(&cfb->reg_b0_lock);
	ret = !!(cyber2000_grphr(EXT_LATCH2, cfb) & EXT_LATCH2_I2C_CLK);
	spin_unlock(&cfb->reg_b0_lock);

	return ret;
}

static int cyber2000fb_i2c_register(struct cfb_info *cfb)
{
	strscpy(cfb->i2c_adapter.name, cfb->fb.fix.id,
		sizeof(cfb->i2c_adapter.name));
	cfb->i2c_adapter.owner = THIS_MODULE;
	cfb->i2c_adapter.algo_data = &cfb->i2c_algo;
	cfb->i2c_adapter.dev.parent = cfb->fb.device;
	cfb->i2c_algo.setsda = cyber2000fb_i2c_setsda;
	cfb->i2c_algo.setscl = cyber2000fb_i2c_setscl;
	cfb->i2c_algo.getsda = cyber2000fb_i2c_getsda;
	cfb->i2c_algo.getscl = cyber2000fb_i2c_getscl;
	cfb->i2c_algo.udelay = 5;
	cfb->i2c_algo.timeout = msecs_to_jiffies(100);
	cfb->i2c_algo.data = cfb;

	return i2c_bit_add_bus(&cfb->i2c_adapter);
}

static void cyber2000fb_i2c_unregister(struct cfb_info *cfb)
{
	i2c_del_adapter(&cfb->i2c_adapter);
}
#else
#define cyber2000fb_i2c_register(cfb)	(0)
#define cyber2000fb_i2c_unregister(cfb)	do { } while (0)
#endif

/*
 * These parameters give
 * 640x480, hsync 31.5kHz, vsync 60Hz
 */
static const struct fb_videomode cyber2000fb_default_mode = {
	.refresh	= 60,
	.xres		= 640,
	.yres		= 480,
	.pixclock	= 39722,
	.left_margin	= 56,
	.right_margin	= 16,
	.upper_margin	= 34,
	.lower_margin	= 9,
	.hsync_len	= 88,
	.vsync_len	= 2,
	.sync		= FB_SYNC_COMP_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
	.vmode		= FB_VMODE_NONINTERLACED
};

static char igs_regs[] = {
	EXT_CRT_IRQ,		0,
	EXT_CRT_TEST,		0,
	EXT_SYNC_CTL,		0,
	EXT_SEG_WRITE_PTR,	0,
	EXT_SEG_READ_PTR,	0,
	EXT_BIU_MISC,		EXT_BIU_MISC_LIN_ENABLE |
				EXT_BIU_MISC_COP_ENABLE |
				EXT_BIU_MISC_COP_BFC,
	EXT_FUNC_CTL,		0,
	CURS_H_START,		0,
	CURS_H_START + 1,	0,
	CURS_H_PRESET,		0,
	CURS_V_START,		0,
	CURS_V_START + 1,	0,
	CURS_V_PRESET,		0,
	CURS_CTL,		0,
	EXT_ATTRIB_CTL,		EXT_ATTRIB_CTL_EXT,
	EXT_OVERSCAN_RED,	0,
	EXT_OVERSCAN_GREEN,	0,
	EXT_OVERSCAN_BLUE,	0,

	/* some of these are questionable when we have a BIOS */
	EXT_MEM_CTL0,		EXT_MEM_CTL0_7CLK |
				EXT_MEM_CTL0_RAS_1 |
				EXT_MEM_CTL0_MULTCAS,
	EXT_HIDDEN_CTL1,	0x30,
	EXT_FIFO_CTL,		0x0b,
	EXT_FIFO_CTL + 1,	0x17,
	0x76,			0x00,
	EXT_HIDDEN_CTL4,	0xc8
};

/*
 * Initialise the CyberPro hardware.  On the CyberPro5XXXX,
 * ensure that we're using the correct PLL (5XXX's may be
 * programmed to use an additional set of PLLs.)
 */
static void cyberpro_init_hw(struct cfb_info *cfb)
{
	int i;

	for (i = 0; i < sizeof(igs_regs); i += 2)
		cyber2000_grphw(igs_regs[i], igs_regs[i + 1], cfb);

	if (cfb->id == ID_CYBERPRO_5000) {
		unsigned char val;
		cyber2000fb_writeb(0xba, 0x3ce, cfb);
		val = cyber2000fb_readb(0x3cf, cfb) & 0x80;
		cyber2000fb_writeb(val, 0x3cf, cfb);
	}
}

static struct cfb_info *cyberpro_alloc_fb_info(unsigned int id, char *name)
{
	struct cfb_info *cfb;

	cfb = kzalloc_obj(struct cfb_info);
	if (!cfb)
		return NULL;


	cfb->id			= id;

	if (id == ID_CYBERPRO_5000)
		cfb->ref_ps	= 40690; /* 24.576 MHz */
	else
		cfb->ref_ps	= 69842; /* 14.31818 MHz (69841?) */

	cfb->divisors[0]	= 1;
	cfb->divisors[1]	= 2;
	cfb->divisors[2]	= 4;

	if (id == ID_CYBERPRO_2000)
		cfb->divisors[3] = 8;
	else
		cfb->divisors[3] = 6;

	strcpy(cfb->fb.fix.id, name);

	cfb->fb.fix.type	= FB_TYPE_PACKED_PIXELS;
	cfb->fb.fix.type_aux	= 0;
	cfb->fb.fix.xpanstep	= 0;
	cfb->fb.fix.ypanstep	= 1;
	cfb->fb.fix.ywrapstep	= 0;

	switch (id) {
	case ID_IGA_1682:
		cfb->fb.fix.accel = 0;
		break;

	case ID_CYBERPRO_2000:
		cfb->fb.fix.accel = FB_ACCEL_IGS_CYBER2000;
		break;

	case ID_CYBERPRO_2010:
		cfb->fb.fix.accel = FB_ACCEL_IGS_CYBER2010;
		break;

	case ID_CYBERPRO_5000:
		cfb->fb.fix.accel = FB_ACCEL_IGS_CYBER5000;
		break;
	}

	cfb->fb.var.nonstd	= 0;
	cfb->fb.var.activate	= FB_ACTIVATE_NOW;
	cfb->fb.var.height	= -1;
	cfb->fb.var.width	= -1;
	cfb->fb.var.accel_flags	= FB_ACCELF_TEXT;

	cfb->fb.fbops		= &cyber2000fb_ops;
	cfb->fb.flags		= FBINFO_HWACCEL_YPAN;
	cfb->fb.pseudo_palette	= cfb->pseudo_palette;

	spin_lock_init(&cfb->reg_b0_lock);

	fb_alloc_cmap(&cfb->fb.cmap, NR_PALETTE, 0);

	return cfb;
}

static void cyberpro_free_fb_info(struct cfb_info *cfb)
{
	if (cfb) {
		/*
		 * Free the colourmap
		 */
		fb_alloc_cmap(&cfb->fb.cmap, 0, 0);

		kfree(cfb);
	}
}

/*
 * Parse Cyber2000fb options.  Usage:
 *  video=cyber2000:font:fontname
 */
#ifndef MODULE
static int cyber2000fb_setup(char *options)
{
	char *opt;

	if (!options || !*options)
		return 0;

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

		if (strncmp(opt, "font:", 5) == 0) {
			static char default_font_storage[40];

			strscpy(default_font_storage, opt + 5,
				sizeof(default_font_storage));
			default_font = default_font_storage;
			continue;
		}

		printk(KERN_ERR "CyberPro20x0: unknown parameter: %s\n", opt);
	}
	return 0;
}
#endif  /*  MODULE  */

/*
 * The CyberPro chips can be placed on many different bus types.
 * This probe function is common to all bus types.  The bus-specific
 * probe function is expected to have:
 *  - enabled access to the linear memory region
 *  - memory mapped access to the registers
 *  - initialised mem_ctl1 and mem_ctl2 appropriately.
 */
static int cyberpro_common_probe(struct cfb_info *cfb)
{
	u_long smem_size;
	u_int h_sync, v_sync;
	int err;

	cyberpro_init_hw(cfb);

	/*
	 * Get the video RAM size and width from the VGA register.
	 * This should have been already initialised by the BIOS,
	 * but if it's garbage, claim default 1MB VRAM (woody)
	 */
	cfb->mem_ctl1 = cyber2000_grphr(EXT_MEM_CTL1, cfb);
	cfb->mem_ctl2 = cyber2000_grphr(EXT_MEM_CTL2, cfb);

	/*
	 * Determine the size of the memory.
	 */
	switch (cfb->mem_ctl2 & MEM_CTL2_SIZE_MASK) {
	case MEM_CTL2_SIZE_4MB:
		smem_size = 0x00400000;
		break;
	case MEM_CTL2_SIZE_2MB:
		smem_size = 0x00200000;
		break;
	case MEM_CTL2_SIZE_1MB:
		smem_size = 0x00100000;
		break;
	default:
		smem_size = 0x00100000;
		break;
	}

	cfb->fb.fix.smem_len   = smem_size;
	cfb->fb.fix.mmio_len   = MMIO_SIZE;
	cfb->fb.screen_base    = cfb->region;

#ifdef CONFIG_FB_CYBER2000_DDC
	if (cyber2000fb_setup_ddc_bus(cfb) == 0)
		cfb->ddc_registered = true;
#endif

	err = -EINVAL;
	if (!fb_find_mode(&cfb->fb.var, &cfb->fb, NULL, NULL, 0,
			  &cyber2000fb_default_mode, 8)) {
		printk(KERN_ERR "%s: no valid mode found\n", cfb->fb.fix.id);
		goto failed;
	}

	cfb->fb.var.yres_virtual = cfb->fb.fix.smem_len * 8 /
			(cfb->fb.var.bits_per_pixel * cfb->fb.var.xres_virtual);

	if (cfb->fb.var.yres_virtual < cfb->fb.var.yres)
		cfb->fb.var.yres_virtual = cfb->fb.var.yres;

/*	fb_set_var(&cfb->fb.var, -1, &cfb->fb); */

	/*
	 * Calculate the hsync and vsync frequencies.  Note that
	 * we split the 1e12 constant up so that we can preserve
	 * the precision and fit the results into 32-bit registers.
	 *  (1953125000 * 512 = 1e12)
	 */
	h_sync = 1953125000 / cfb->fb.var.pixclock;
	h_sync = h_sync * 512 / (cfb->fb.var.xres + cfb->fb.var.left_margin +
		 cfb->fb.var.right_margin + cfb->fb.var.hsync_len);
	v_sync = h_sync / (cfb->fb.var.yres + cfb->fb.var.upper_margin +
		 cfb->fb.var.lower_margin + cfb->fb.var.vsync_len);

	printk(KERN_INFO "%s: %dKiB VRAM, using %dx%d, %d.%03dkHz, %dHz\n",
		cfb->fb.fix.id, cfb->fb.fix.smem_len >> 10,
		cfb->fb.var.xres, cfb->fb.var.yres,
		h_sync / 1000, h_sync % 1000, v_sync);

	err = cyber2000fb_i2c_register(cfb);
	if (err)
		goto failed;

	err = register_framebuffer(&cfb->fb);
	if (err)
		cyber2000fb_i2c_unregister(cfb);

failed:
#ifdef CONFIG_FB_CYBER2000_DDC
	if (err && cfb->ddc_registered)
		i2c_del_adapter(&cfb->ddc_adapter);
#endif
	return err;
}

static void cyberpro_common_remove(struct cfb_info *cfb)
{
	unregister_framebuffer(&cfb->fb);
#ifdef CONFIG_FB_CYBER2000_DDC
	if (cfb->ddc_registered)
		i2c_del_adapter(&cfb->ddc_adapter);
#endif
	cyber2000fb_i2c_unregister(cfb);
}

static void cyberpro_common_resume(struct cfb_info *cfb)
{
	cyberpro_init_hw(cfb);

	/*
	 * Reprogram the MEM_CTL1 and MEM_CTL2 registers
	 */
	cyber2000_grphw(EXT_MEM_CTL1, cfb->mem_ctl1, cfb);
	cyber2000_grphw(EXT_MEM_CTL2, cfb->mem_ctl2, cfb);

	/*
	 * Restore the old video mode and the palette.
	 * We also need to tell fbcon to redraw the console.
	 */
	cyber2000fb_set_par(&cfb->fb);
}

/*
 * We need to wake up the CyberPro, and make sure its in linear memory
 * mode.  Unfortunately, this is specific to the platform and card that
 * we are running on.
 *
 * On x86 and ARM, should we be initialising the CyberPro first via the
 * IO registers, and then the MMIO registers to catch all cases?  Can we
 * end up in the situation where the chip is in MMIO mode, but not awake
 * on an x86 system?
 */
static int cyberpro_pci_enable_mmio(struct cfb_info *cfb)
{
	unsigned char val;

#if defined(__sparc_v9__)
#error "You lose, consult DaveM."
#elif defined(__sparc__)
	/*
	 * SPARC does not have an "outb" instruction, so we generate
	 * I/O cycles storing into a reserved memory space at
	 * physical address 0x3000000
	 */
	unsigned char __iomem *iop;

	iop = ioremap(0x3000000, 0x5000);
	if (iop == NULL) {
		printk(KERN_ERR "iga5000: cannot map I/O\n");
		return -ENOMEM;
	}

	writeb(0x18, iop + 0x46e8);
	writeb(0x01, iop + 0x102);
	writeb(0x08, iop + 0x46e8);
	writeb(EXT_BIU_MISC, iop + 0x3ce);
	writeb(EXT_BIU_MISC_LIN_ENABLE, iop + 0x3cf);

	iounmap(iop);
#else
	/*
	 * Most other machine types are "normal", so
	 * we use the standard IO-based wakeup.
	 */
	outb(0x18, 0x46e8);
	outb(0x01, 0x102);
	outb(0x08, 0x46e8);
	outb(EXT_BIU_MISC, 0x3ce);
	outb(EXT_BIU_MISC_LIN_ENABLE, 0x3cf);
#endif

	/*
	 * Allow the CyberPro to accept PCI burst accesses
	 */
	if (cfb->id == ID_CYBERPRO_2010) {
		printk(KERN_INFO "%s: NOT enabling PCI bursts\n",
		       cfb->fb.fix.id);
	} else {
		val = cyber2000_grphr(EXT_BUS_CTL, cfb);
		if (!(val & EXT_BUS_CTL_PCIBURST_WRITE)) {
			printk(KERN_INFO "%s: enabling PCI bursts\n",
				cfb->fb.fix.id);

			val |= EXT_BUS_CTL_PCIBURST_WRITE;

			if (cfb->id == ID_CYBERPRO_5000)
				val |= EXT_BUS_CTL_PCIBURST_READ;

			cyber2000_grphw(EXT_BUS_CTL, val, cfb);
		}
	}

	return 0;
}

static int cyberpro_pci_probe(struct pci_dev *dev,
			      const struct pci_device_id *id)
{
	struct cfb_info *cfb;
	char name[16];
	int err;

	sprintf(name, "CyberPro%4X", id->device);

	err = aperture_remove_conflicting_pci_devices(dev, name);
	if (err)
		return err;

	err = pci_enable_device(dev);
	if (err)
		return err;

	err = -ENOMEM;
	cfb = cyberpro_alloc_fb_info(id->driver_data, name);
	if (!cfb)
		goto failed_release;

	err = pci_request_regions(dev, cfb->fb.fix.id);
	if (err)
		goto failed_regions;

	cfb->irq = dev->irq;
	cfb->region = pci_ioremap_bar(dev, 0);
	if (!cfb->region) {
		err = -ENOMEM;
		goto failed_ioremap;
	}

	cfb->regs = cfb->region + MMIO_OFFSET;
	cfb->fb.device = &dev->dev;
	cfb->fb.fix.mmio_start = pci_resource_start(dev, 0) + MMIO_OFFSET;
	cfb->fb.fix.smem_start = pci_resource_start(dev, 0);

	/*
	 * Bring up the hardware.  This is expected to enable access
	 * to the linear memory region, and allow access to the memory
	 * mapped registers.  Also, mem_ctl1 and mem_ctl2 must be
	 * initialised.
	 */
	err = cyberpro_pci_enable_mmio(cfb);
	if (err)
		goto failed;

	/*
	 * Use MCLK from BIOS. FIXME: what about hotplug?
	 */
	cfb->mclk_mult = cyber2000_grphr(EXT_MCLK_MULT, cfb);
	cfb->mclk_div  = cyber2000_grphr(EXT_MCLK_DIV, cfb);

#ifdef __arm__
	/*
	 * MCLK on the NetWinder and the Shark is fixed at 75MHz
	 */
	if (machine_is_netwinder()) {
		cfb->mclk_mult = 0xdb;
		cfb->mclk_div  = 0x54;
	}
#endif

	err = cyberpro_common_probe(cfb);
	if (err)
		goto failed;

	/*
	 * Our driver data
	 */
	pci_set_drvdata(dev, cfb);
	if (int_cfb_info == NULL)
		int_cfb_info = cfb;

	return 0;

failed:
	iounmap(cfb->region);
failed_ioremap:
	pci_release_regions(dev);
failed_regions:
	cyberpro_free_fb_info(cfb);
failed_release:
	pci_disable_device(dev);
	return err;
}

static void cyberpro_pci_remove(struct pci_dev *dev)
{
	struct cfb_info *cfb = pci_get_drvdata(dev);

	if (cfb) {
		cyberpro_common_remove(cfb);
		iounmap(cfb->region);
		cyberpro_free_fb_info(cfb);

		if (cfb == int_cfb_info)
			int_cfb_info = NULL;

		pci_release_regions(dev);
		pci_disable_device(dev);
	}
}

static int __maybe_unused cyberpro_pci_suspend(struct device *dev)
{
	return 0;
}

/*
 * Re-initialise the CyberPro hardware
 */
static int __maybe_unused cyberpro_pci_resume(struct device *dev)
{
	struct cfb_info *cfb = dev_get_drvdata(dev);

	if (cfb) {
		cyberpro_pci_enable_mmio(cfb);
		cyberpro_common_resume(cfb);
	}

	return 0;
}

static struct pci_device_id cyberpro_pci_table[] = {
/*	Not yet
 *	{ PCI_VENDOR_ID_INTERG, PCI_DEVICE_ID_INTERG_1682,
 *		PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_IGA_1682 },
 */
	{ PCI_VENDOR_ID_INTERG, PCI_DEVICE_ID_INTERG_2000,
		PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_CYBERPRO_2000 },
	{ PCI_VENDOR_ID_INTERG, PCI_DEVICE_ID_INTERG_2010,
		PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_CYBERPRO_2010 },
	{ PCI_VENDOR_ID_INTERG, PCI_DEVICE_ID_INTERG_5000,
		PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_CYBERPRO_5000 },
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, cyberpro_pci_table);

static SIMPLE_DEV_PM_OPS(cyberpro_pci_pm_ops,
			 cyberpro_pci_suspend,
			 cyberpro_pci_resume);

static struct pci_driver cyberpro_driver = {
	.name		= "CyberPro",
	.probe		= cyberpro_pci_probe,
	.remove		= cyberpro_pci_remove,
	.driver.pm	= &cyberpro_pci_pm_ops,
	.id_table	= cyberpro_pci_table
};

/*
 * I don't think we can use the "module_init" stuff here because
 * the fbcon stuff may not be initialised yet.  Hence the #ifdef
 * around module_init.
 *
 * Tony: "module_init" is now required
 */
static int __init cyber2000fb_init(void)
{
	int ret = -1, err;

#ifndef MODULE
	char *option = NULL;
#endif

	if (fb_modesetting_disabled("CyberPro"))
		return -ENODEV;

#ifndef MODULE
	if (fb_get_options("cyber2000fb", &option))
		return -ENODEV;
	cyber2000fb_setup(option);
#endif

	err = pci_register_driver(&cyberpro_driver);
	if (!err)
		ret = 0;

	return ret ? err : 0;
}
module_init(cyber2000fb_init);

static void __exit cyberpro_exit(void)
{
	pci_unregister_driver(&cyberpro_driver);
}
module_exit(cyberpro_exit);

MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("CyberPro 2000, 2010 and 5000 framebuffer driver");
MODULE_LICENSE("GPL");
