// 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");