Linux-2.6.12-rc2

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / video / sstfb.c

/*
 * linux/drivers/video/sstfb.c -- voodoo graphics frame buffer
 *
 *     Copyright (c) 2000-2002 Ghozlane Toumi <gtoumi@laposte.net>
 *
 *     Created 15 Jan 2000 by Ghozlane Toumi
 *
 * Contributions (and many thanks) :
 *
 * 03/2001 James Simmons   <jsimmons@infradead.org>
 * 04/2001 Paul Mundt      <lethal@chaoticdreams.org>
 * 05/2001 Urs Ganse       <ursg@uni.de>
 *      (initial work on voodoo2 port, interlace)
 * 09/2002 Helge Deller    <deller@gmx.de>
 *      (enable driver on big-endian machines (hppa), ioctl fixes)
 * 12/2002 Helge Deller    <deller@gmx.de>
 *      (port driver to new frambuffer infrastructure)
 * 01/2003 Helge Deller    <deller@gmx.de>
 *      (initial work on fb hardware acceleration for voodoo2)
 *
 */

/*
 * The voodoo1 has the following memory mapped address space:
 * 0x000000 - 0x3fffff : registers              (4MB)
 * 0x400000 - 0x7fffff : linear frame buffer    (4MB)
 * 0x800000 - 0xffffff : texture memory         (8MB)
 */

/*
 * misc notes, TODOs, toASKs, and deep thoughts

-TODO: at one time or another test that the mode is acceptable by the monitor
-ASK: Can I choose different ordering for the color bitfields (rgba argb ...)
      wich one should i use ? is there any preferred one ? It seems ARGB is
      the one ...
-TODO: in  set_var check the validity of timings (hsync vsync)...
-TODO: check and recheck the use of sst_wait_idle : we don't flush the fifo via
       a nop command. so it's ok as long as the commands we pass don't go
       through the fifo. warning: issuing a nop command seems to need pci_fifo
-FIXME: in case of failure in the init sequence, be sure we return to a safe
        state.
-FIXME: 4MB boards have banked memory (FbiInit2 bits 1 & 20)
 */

/*
 * debug info
 * SST_DEBUG : enable debugging
 * SST_DEBUG_REG : debug registers
 *   0 :  no debug
 *   1 : dac calls, [un]set_bits, FbiInit
 *   2 : insane debug level (log every register read/write)
 * SST_DEBUG_FUNC : functions
 *   0 : no debug
 *   1 : function call / debug ioctl
 *   2 : variables
 *   3 : flood . you don't want to do that. trust me.
 * SST_DEBUG_VAR : debug display/var structs
 *   0 : no debug
 *   1 : dumps display, fb_var
 *
 * sstfb specific ioctls:
 *              toggle vga (0x46db) : toggle vga_pass_through
 *              fill fb    (0x46dc) : fills fb
 *              test disp  (0x46de) : draws a test image
 */

#undef SST_DEBUG

/* enable 24/32 bpp functions ? (completely untested!) */
#undef EN_24_32_BPP

/*
  Default video mode .
  0 800x600@60  took from glide
  1 640x480@75  took from glide
  2 1024x768@76 std fb.mode
  3 640x480@60  glide default */
#define DEFAULT_MODE 3 

/*
 * Includes
 */

#include <linux/config.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/ioctl.h>
#include <asm/uaccess.h>
#include <video/sstfb.h>


/* initialized by setup */

static int vgapass;             /* enable Vga passthrough cable */
static int mem;                 /* mem size in MB, 0 = autodetect */
static int clipping = 1;        /* use clipping (slower, safer) */
static int gfxclk;              /* force FBI freq in Mhz . Dangerous */
static int slowpci;             /* slow PCI settings */

static char *mode_option __devinitdata;

enum {
        ID_VOODOO1 = 0,
        ID_VOODOO2 = 1,
};

#define IS_VOODOO2(par) ((par)->type == ID_VOODOO2)

static struct sst_spec voodoo_spec[] __devinitdata = {
 { .name = "Voodoo Graphics", .default_gfx_clock = 50000, .max_gfxclk = 60 },
 { .name = "Voodoo2",         .default_gfx_clock = 75000, .max_gfxclk = 85 },
};

static struct fb_var_screeninfo sstfb_default =
#if ( DEFAULT_MODE == 0 )
    { /* 800x600@60, 16 bpp .borowed from glide/sst1/include/sst1init.h */
    800, 600, 800, 600, 0, 0, 16, 0,
    {11, 5, 0}, {5, 6, 0}, {0, 5, 0}, {0, 0, 0},
    0, 0, -1, -1, 0,
    25000, 86, 41, 23, 1, 127, 4,
    0, FB_VMODE_NONINTERLACED };
#elif ( DEFAULT_MODE == 1 )
    {/* 640x480@75, 16 bpp .borowed from glide/sst1/include/sst1init.h */
    640, 480, 640, 480, 0, 0, 16, 0,
    {11, 5, 0}, {5, 6, 0}, {0, 5, 0}, {0, 0, 0},
    0, 0, -1, -1, 0,
    31746, 118, 17, 16, 1, 63, 3,
    0, FB_VMODE_NONINTERLACED };
#elif ( DEFAULT_MODE == 2 )
    { /* 1024x768@76 took from my /etc/fb.modes */
    1024, 768, 1024, 768,0, 0, 16,0,
    {11, 5, 0}, {5, 6, 0}, {0, 5, 0}, {0, 0, 0},
    0, 0, -1, -1, 0,
    11764, 208, 8, 36, 16, 120, 3 ,
    0, FB_VMODE_NONINTERLACED };
#elif ( DEFAULT_MODE == 3 )
    { /* 640x480@60 , 16bpp glide default ?*/
    640, 480, 640, 480, 0, 0, 16, 0,
    {11, 5, 0}, {5, 6, 0}, {0, 5, 0}, {0, 0, 0},
    0, 0, -1, -1, 0,
    39721 ,  38, 26 ,  25 ,18  , 96 ,2,
    0, FB_VMODE_NONINTERLACED };
#elif
    #error "Invalid DEFAULT_MODE value !"
#endif


/*
 * debug functions
 */

static void sstfb_drawdebugimage(struct fb_info *info);
static int sstfb_dump_regs(struct fb_info *info);


#if (SST_DEBUG_REG > 0)
static void sst_dbg_print_read_reg(u32 reg, u32 val) {
        const char *regname;
        switch (reg) {
        case FBIINIT0:  regname = "FbiInit0"; break;
        case FBIINIT1:  regname = "FbiInit1"; break;
        case FBIINIT2:  regname = "FbiInit2"; break;
        case FBIINIT3:  regname = "FbiInit3"; break;
        case FBIINIT4:  regname = "FbiInit4"; break;
        case FBIINIT5:  regname = "FbiInit5"; break;
        case FBIINIT6:  regname = "FbiInit6"; break;
        default:        regname = NULL;       break;
        }
        if (regname == NULL)
                r_ddprintk("sst_read(%#x): %#x\n", reg, val);
        else
                r_dprintk(" sst_read(%s): %#x\n", regname, val);
}

static void sst_dbg_print_write_reg(u32 reg, u32 val) {
        const char *regname;
        switch (reg) {
        case FBIINIT0:  regname = "FbiInit0"; break;
        case FBIINIT1:  regname = "FbiInit1"; break;
        case FBIINIT2:  regname = "FbiInit2"; break;
        case FBIINIT3:  regname = "FbiInit3"; break;
        case FBIINIT4:  regname = "FbiInit4"; break;
        case FBIINIT5:  regname = "FbiInit5"; break;
        case FBIINIT6:  regname = "FbiInit6"; break;
        default:        regname = NULL;       break;
        }
        if (regname == NULL)
                r_ddprintk("sst_write(%#x, %#x)\n", reg, val);
        else
                r_dprintk(" sst_write(%s, %#x)\n", regname, val);
}
#else /*  (SST_DEBUG_REG > 0) */
#  define sst_dbg_print_read_reg(reg, val)      do {} while(0)
#  define sst_dbg_print_write_reg(reg, val)     do {} while(0)
#endif /*  (SST_DEBUG_REG > 0) */

/*
 * hardware access functions
 */

/* register access */
#define sst_read(reg)           __sst_read(par->mmio_vbase, reg)
#define sst_write(reg,val)      __sst_write(par->mmio_vbase, reg, val)
#define sst_set_bits(reg,val)   __sst_set_bits(par->mmio_vbase, reg, val)
#define sst_unset_bits(reg,val) __sst_unset_bits(par->mmio_vbase, reg, val)
#define sst_dac_read(reg)       __sst_dac_read(par->mmio_vbase, reg)
#define sst_dac_write(reg,val)  __sst_dac_write(par->mmio_vbase, reg, val)
#define dac_i_read(reg)         __dac_i_read(par->mmio_vbase, reg)
#define dac_i_write(reg,val)    __dac_i_write(par->mmio_vbase, reg, val)

static inline u32 __sst_read(u8 __iomem *vbase, u32 reg)
{
        u32 ret = readl(vbase + reg);
        sst_dbg_print_read_reg(reg, ret);
        return ret;
}

static inline void __sst_write(u8 __iomem *vbase, u32 reg, u32 val)
{
        sst_dbg_print_write_reg(reg, val);
        writel(val, vbase + reg);
}

static inline void __sst_set_bits(u8 __iomem *vbase, u32 reg, u32 val)
{
        r_dprintk("sst_set_bits(%#x, %#x)\n", reg, val);
        __sst_write(vbase, reg, __sst_read(vbase, reg) | val);
}

static inline void __sst_unset_bits(u8 __iomem *vbase, u32 reg, u32 val)
{
        r_dprintk("sst_unset_bits(%#x, %#x)\n", reg, val);
        __sst_write(vbase, reg, __sst_read(vbase, reg) & ~val);
}

/*
 * wait for the fbi chip. ASK: what happens if the fbi is stuck ?
 *
 * the FBI is supposed to be ready if we receive 5 time
 * in a row a "idle" answer to our requests
 */

#define sst_wait_idle() __sst_wait_idle(par->mmio_vbase)

static int __sst_wait_idle(u8 __iomem *vbase)
{
        int count = 0;

        /* if (doFBINOP) __sst_write(vbase, NOPCMD, 0); */

        while(1) {
                if (__sst_read(vbase, STATUS) & STATUS_FBI_BUSY) {
                        f_dddprintk("status: busy\n");
/* FIXME basicaly, this is a busy wait. maybe not that good. oh well;
 * this is a small loop after all.
 * Or maybe we should use mdelay() or udelay() here instead ? */
                        count = 0;
                } else {
                        count++;
                        f_dddprintk("status: idle(%d)\n", count);
                }
                if (count >= 5) return 1;
/* XXX  do something to avoid hanging the machine if the voodoo is out */
        }
}


/* dac access */
/* dac_read should be remaped to FbiInit2 (via the pci reg init_enable) */
static u8 __sst_dac_read(u8 __iomem *vbase, u8 reg)
{
        u8 ret;

        reg &= 0x07;
        __sst_write(vbase, DAC_DATA, ((u32)reg << 8) | DAC_READ_CMD );
        __sst_wait_idle(vbase);
        /* udelay(10); */
        ret = __sst_read(vbase, DAC_READ) & 0xff;
        r_dprintk("sst_dac_read(%#x): %#x\n", reg, ret);

        return ret;
}

static void __sst_dac_write(u8 __iomem *vbase, u8 reg, u8 val)
{
        r_dprintk("sst_dac_write(%#x, %#x)\n", reg, val);
        reg &= 0x07;
        __sst_write(vbase, DAC_DATA,(((u32)reg << 8)) | (u32)val);
}

/* indexed access to ti/att dacs */
static u32 __dac_i_read(u8 __iomem *vbase, u8 reg)
{
        u32 ret;

        __sst_dac_write(vbase, DACREG_ADDR_I, reg);
        ret = __sst_dac_read(vbase, DACREG_DATA_I);
        r_dprintk("sst_dac_read_i(%#x): %#x\n", reg, ret);
        return ret;
}
static void __dac_i_write(u8 __iomem *vbase, u8 reg,u8 val)
{
        r_dprintk("sst_dac_write_i(%#x, %#x)\n", reg, val);
        __sst_dac_write(vbase, DACREG_ADDR_I, reg);
        __sst_dac_write(vbase, DACREG_DATA_I, val);
}

/* compute the m,n,p  , returns the real freq
 * (ics datasheet :  N <-> N1 , P <-> N2)
 *
 * Fout= Fref * (M+2)/( 2^P * (N+2))
 *  we try to get close to the asked freq
 *  with P as high, and M as low as possible
 * range:
 * ti/att : 0 <= M <= 255; 0 <= P <= 3; 0<= N <= 63
 * ics    : 1 <= M <= 127; 0 <= P <= 3; 1<= N <= 31
 * we'll use the lowest limitation, should be precise enouth
 */
static int sst_calc_pll(const int freq, int *freq_out, struct pll_timing *t)
{
        int m, m2, n, p, best_err, fout;
        int best_n = -1;
        int best_m = -1;

        best_err = freq;
        p = 3;
        /* f * 2^P = vco should be less than VCOmax ~ 250 MHz for ics*/
        while (((1 << p) * freq > VCO_MAX) && (p >= 0))
                p--;
        if (p == -1)
                return -EINVAL;
        for (n = 1; n < 32; n++) {
                /* calc 2 * m so we can round it later*/
                m2 = (2 * freq * (1 << p) * (n + 2) ) / DAC_FREF - 4 ;

                m = (m2 % 2 ) ? m2/2+1 : m2/2 ;
                if (m >= 128)
                        break;
                fout = (DAC_FREF * (m + 2)) / ((1 << p) * (n + 2));
                if ((abs(fout - freq) < best_err) && (m > 0)) {
                        best_n = n;
                        best_m = m;
                        best_err = abs(fout - freq);
                        /* we get the lowest m , allowing 0.5% error in freq*/
                        if (200*best_err < freq) break;
                }
        }
        if (best_n == -1)  /* unlikely, but who knows ? */
                return -EINVAL;
        t->p = p;
        t->n = best_n;
        t->m = best_m;
        *freq_out = (DAC_FREF * (t->m + 2)) / ((1 << t->p) * (t->n + 2));
        f_ddprintk ("m: %d, n: %d, p: %d, F: %dKhz\n",
                  t->m, t->n, t->p, *freq_out);
        return 0;
}

/*
 * clear lfb screen
 */
static void sstfb_clear_screen(struct fb_info *info)
{
        /* clear screen */
        fb_memset(info->screen_base, 0, info->fix.smem_len);
}


/**
 *      sstfb_check_var - Optional function.  Validates a var passed in.
 *      @var: frame buffer variable screen structure
 *      @info: frame buffer structure that represents a single frame buffer
 */
static int sstfb_check_var(struct fb_var_screeninfo *var,
                struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        int hSyncOff   = var->xres + var->right_margin + var->left_margin;
        int vSyncOff   = var->yres + var->lower_margin + var->upper_margin;
        int vBackPorch = var->left_margin, yDim = var->yres;
        int vSyncOn    = var->vsync_len;
        int tiles_in_X, real_length;
        unsigned int freq;

        if (sst_calc_pll(PICOS2KHZ(var->pixclock), &freq, &par->pll)) {
                eprintk("Pixclock at %ld KHZ out of range\n",
                                PICOS2KHZ(var->pixclock));
                return -EINVAL;
        }
        var->pixclock = KHZ2PICOS(freq);
        
        if (var->vmode & FB_VMODE_INTERLACED)
                vBackPorch += (vBackPorch % 2);
        if (var->vmode & FB_VMODE_DOUBLE) {
                vBackPorch <<= 1;
                yDim <<=1;
                vSyncOn <<=1;
                vSyncOff <<=1;
        }

        switch (var->bits_per_pixel) {
        case 0 ... 16 :
                var->bits_per_pixel = 16;
                break;
#ifdef EN_24_32_BPP
        case 17 ... 24 :
                var->bits_per_pixel = 24;
                break;
        case 25 ... 32 :
                var->bits_per_pixel = 32;
                break;
#endif
        default :
                eprintk("Unsupported bpp %d\n", var->bits_per_pixel);
                return -EINVAL;
        }
        
        /* validity tests */
        if ((var->xres <= 1) || (yDim <= 0 )
           || (var->hsync_len <= 1)
           || (hSyncOff <= 1)
           || (var->left_margin <= 2)
           || (vSyncOn <= 0)
           || (vSyncOff <= 0)
           || (vBackPorch <= 0)) {
                return -EINVAL;
        }

        if (IS_VOODOO2(par)) {
                /* Voodoo 2 limits */
                tiles_in_X = (var->xres + 63 ) / 64 * 2;                

                if (((var->xres - 1) >= POW2(11)) || (yDim >= POW2(11))) {
                        eprintk("Unsupported resolution %dx%d\n",
                                 var->xres, var->yres);
                        return -EINVAL;
                }

                if (((var->hsync_len-1) >= POW2(9))
                   || ((hSyncOff-1) >= POW2(11))
                   || ((var->left_margin - 2) >= POW2(9))
                   || (vSyncOn >= POW2(13))
                   || (vSyncOff >= POW2(13))
                   || (vBackPorch >= POW2(9))
                   || (tiles_in_X >= POW2(6))
                   || (tiles_in_X <= 0)) {
                        eprintk("Unsupported Timings\n");
                        return -EINVAL;
                }
        } else {
                /* Voodoo limits */
                tiles_in_X = (var->xres + 63 ) / 64;

                if (var->vmode) {
                        eprintk("Interlace/Doublescan not supported %#x\n",
                                var->vmode);
                        return -EINVAL;
                }
                if (((var->xres - 1) >= POW2(10)) || (var->yres >= POW2(10))) {
                        eprintk("Unsupported resolution %dx%d\n",
                                 var->xres, var->yres);
                        return -EINVAL;
                }
                if (((var->hsync_len - 1) >= POW2(8))
                   || ((hSyncOff-1) >= POW2(10))
                   || ((var->left_margin - 2) >= POW2(8))
                   || (vSyncOn >= POW2(12))
                   || (vSyncOff >= POW2(12))
                   || (vBackPorch >= POW2(8))
                   || (tiles_in_X >= POW2(4))
                   || (tiles_in_X <= 0)) {
                        eprintk("Unsupported Timings\n");
                        return -EINVAL;
                }
        }

        /* it seems that the fbi uses tiles of 64x16 pixels to "map" the mem */
        /* FIXME: i don't like this... looks wrong */
        real_length = tiles_in_X  * (IS_VOODOO2(par) ? 32 : 64 )
                      * ((var->bits_per_pixel == 16) ? 2 : 4);

        if ((real_length * yDim) > info->fix.smem_len) {
                eprintk("Not enough video memory\n");
                return -ENOMEM;
        }

        var->sync &= (FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT);
        var->vmode &= (FB_VMODE_INTERLACED | FB_VMODE_DOUBLE);
        var->xoffset = 0;
        var->yoffset = 0;
        var->height  = -1;
        var->width   = -1;

        /*
         * correct the color bit fields
         */
        /* var->{red|green|blue}.msb_right = 0; */

        switch (var->bits_per_pixel) {
        case 16:        /* RGB 565  LfbMode 0 */
                var->red.length    = 5;
                var->green.length  = 6;
                var->blue.length   = 5;
                var->transp.length = 0;

                var->red.offset    = 11;
                var->green.offset  = 5;
                var->blue.offset   = 0;
                var->transp.offset = 0;
                break;
#ifdef EN_24_32_BPP
        case 24:        /* RGB 888 LfbMode 4 */
        case 32:        /* ARGB 8888 LfbMode 5 */
                var->red.length    = 8;
                var->green.length  = 8;
                var->blue.length   = 8;
                var->transp.length = 0;

                var->red.offset    = 16;
                var->green.offset  = 8;
                var->blue.offset   = 0;
                var->transp.offset = 0; /* in 24bpp we fake a 32 bpp mode */
                break;
#endif
        default:
                return -EINVAL;
        }
        return 0;
}

/**
 *      sstfb_set_par - Optional function.  Alters the hardware state.
 *      @info: frame buffer structure that represents a single frame buffer
 */
static int sstfb_set_par(struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u32 lfbmode, fbiinit1, fbiinit2, fbiinit3, fbiinit5, fbiinit6=0;
        struct pci_dev *sst_dev = par->dev;
        unsigned int freq;
        int ntiles;

        par->hSyncOff   = info->var.xres + info->var.right_margin + info->var.left_margin;

        par->yDim       = info->var.yres;
        par->vSyncOn    = info->var.vsync_len;
        par->vSyncOff   = info->var.yres + info->var.lower_margin + info->var.upper_margin;
        par->vBackPorch = info->var.upper_margin;

        /* We need par->pll */
        sst_calc_pll(PICOS2KHZ(info->var.pixclock), &freq, &par->pll);

        if (info->var.vmode & FB_VMODE_INTERLACED)
                par->vBackPorch += (par->vBackPorch % 2);
        if (info->var.vmode & FB_VMODE_DOUBLE) {
                par->vBackPorch <<= 1;
                par->yDim <<=1;
                par->vSyncOn <<=1;
                par->vSyncOff <<=1;
        }

        if (IS_VOODOO2(par)) {
                /* voodoo2 has 32 pixel wide tiles , BUT stange things
                   happen with odd number of tiles */
                par->tiles_in_X = (info->var.xres + 63 ) / 64 * 2;
        } else {
                /* voodoo1 has 64 pixels wide tiles. */
                par->tiles_in_X = (info->var.xres + 63 ) / 64;
        }

        f_ddprintk("hsync_len hSyncOff vsync_len vSyncOff\n");
        f_ddprintk("%-7d %-8d %-7d %-8d\n",
                   info->var.hsync_len, par->hSyncOff,
                   par->vSyncOn, par->vSyncOff);
        f_ddprintk("left_margin upper_margin xres yres Freq\n");
        f_ddprintk("%-10d %-10d %-4d %-4d %-8ld\n",
                   info->var.left_margin, info->var.upper_margin,
                   info->var.xres, info->var.yres, PICOS2KHZ(info->var.pixclock));

        sst_write(NOPCMD, 0);
        sst_wait_idle();
        pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
        sst_set_bits(FBIINIT1, VIDEO_RESET);
        sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
        sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
        sst_wait_idle();

        /*sst_unset_bits (FBIINIT0, FBI_RESET); / reenable FBI ? */

        sst_write(BACKPORCH, par->vBackPorch << 16 | (info->var.left_margin - 2));
        sst_write(VIDEODIMENSIONS, par->yDim << 16 | (info->var.xres - 1));
        sst_write(HSYNC, (par->hSyncOff - 1) << 16 | (info->var.hsync_len - 1));
        sst_write(VSYNC,       par->vSyncOff << 16 | par->vSyncOn);

        fbiinit2 = sst_read(FBIINIT2);
        fbiinit3 = sst_read(FBIINIT3);

        /* everything is reset. we enable fbiinit2/3 remap : dac acces ok */
        pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
                               PCI_EN_INIT_WR | PCI_REMAP_DAC );

        par->dac_sw.set_vidmod(info, info->var.bits_per_pixel);

        /* set video clock */
        par->dac_sw.set_pll(info, &par->pll, VID_CLOCK);

        /* disable fbiinit2/3 remap */
        pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
                               PCI_EN_INIT_WR);

        /* restore fbiinit2/3 */
        sst_write(FBIINIT2,fbiinit2);
        sst_write(FBIINIT3,fbiinit3);

        fbiinit1 = (sst_read(FBIINIT1) & VIDEO_MASK)
                    | EN_DATA_OE
                    | EN_BLANK_OE
                    | EN_HVSYNC_OE
                    | EN_DCLK_OE
                 /* | (15 << TILES_IN_X_SHIFT) */
                    | SEL_INPUT_VCLK_2X
                 /* | (2 << VCLK_2X_SEL_DEL_SHIFT)
                    | (2 << VCLK_DEL_SHIFT) */;
/* try with vclk_in_delay =0 (bits 29:30) , vclk_out_delay =0 (bits(27:28)
 in (near) future set them accordingly to revision + resolution (cf glide)
 first understand what it stands for :)
 FIXME: there are some artefacts... check for the vclk_in_delay
 lets try with 6ns delay in both vclk_out & in...
 doh... they're still there :\
*/

        ntiles = par->tiles_in_X;
        if (IS_VOODOO2(par)) {
                fbiinit1 |= ((ntiles & 0x20) >> 5) << TILES_IN_X_MSB_SHIFT
                            | ((ntiles & 0x1e) >> 1) << TILES_IN_X_SHIFT;
/* as the only value of importance for us in fbiinit6 is tiles in X (lsb),
   and as reading fbinit 6 will return crap (see FBIINIT6_DEFAULT) we just
   write our value. BTW due to the dac unable to read odd number of tiles, this
   field is always null ... */
                fbiinit6 = (ntiles & 0x1) << TILES_IN_X_LSB_SHIFT;
        }
        else
                fbiinit1 |= ntiles << TILES_IN_X_SHIFT;

        switch (info->var.bits_per_pixel) {
        case 16:
                fbiinit1 |=  SEL_SOURCE_VCLK_2X_SEL;
                break;
#ifdef EN_24_32_BPP
        case 24:
        case 32:
                /* sst_set_bits(FBIINIT1, SEL_SOURCE_VCLK_2X_DIV2 | EN_24BPP);*/
                fbiinit1 |= SEL_SOURCE_VCLK_2X_SEL | EN_24BPP;
                break;
#endif
        default:
                return -EINVAL;
        }
        sst_write(FBIINIT1, fbiinit1);
        if (IS_VOODOO2(par)) {
                sst_write(FBIINIT6, fbiinit6);
                fbiinit5=sst_read(FBIINIT5) & FBIINIT5_MASK ;
                if (info->var.vmode & FB_VMODE_INTERLACED)
                        fbiinit5 |= INTERLACE;
                if (info->var.vmode & FB_VMODE_DOUBLE)
                        fbiinit5 |= VDOUBLESCAN;
                if (info->var.sync & FB_SYNC_HOR_HIGH_ACT)
                        fbiinit5 |= HSYNC_HIGH;
                if (info->var.sync & FB_SYNC_VERT_HIGH_ACT)
                        fbiinit5 |= VSYNC_HIGH;
                sst_write(FBIINIT5, fbiinit5);
        }
        sst_wait_idle();
        sst_unset_bits(FBIINIT1, VIDEO_RESET);
        sst_unset_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
        sst_set_bits(FBIINIT2, EN_DRAM_REFRESH);
        /* disables fbiinit writes */
        pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, PCI_EN_FIFO_WR);

        /* set lfbmode : set mode + front buffer for reads/writes
           + disable pipeline */
        switch (info->var.bits_per_pixel) {
        case 16:
                lfbmode = LFB_565;
                break;
#ifdef EN_24_32_BPP
        case 24:
                lfbmode = LFB_888;
                break;
        case 32:
                lfbmode = LFB_8888;
                break;
#endif
        default:
                return -EINVAL;
        }

#if defined(__BIG_ENDIAN)
        /* Enable byte-swizzle functionality in hardware.
         * With this enabled, all our read- and write-accesses to
         * the voodoo framebuffer can be done in native format, and
         * the hardware will automatically convert it to little-endian.
         * - tested on HP-PARISC, Helge Deller <deller@gmx.de> */
        lfbmode |= ( LFB_WORD_SWIZZLE_WR | LFB_BYTE_SWIZZLE_WR |
                     LFB_WORD_SWIZZLE_RD | LFB_BYTE_SWIZZLE_RD );
#endif
        
        if (clipping) {
                sst_write(LFBMODE, lfbmode | EN_PXL_PIPELINE);
        /*
         * Set "clipping" dimensions. If clipping is disabled and
         * writes to offscreen areas of the framebuffer are performed,
         * the "behaviour is undefined" (_very_ undefined) - Urs
         */
        /* btw, it requires enabling pixel pipeline in LFBMODE .
           off screen read/writes will just wrap and read/print pixels
           on screen. Ugly but not that dangerous */
                f_ddprintk("setting clipping dimensions 0..%d, 0..%d\n",
                            info->var.xres - 1, par->yDim - 1);

                sst_write(CLIP_LEFT_RIGHT, info->var.xres);
                sst_write(CLIP_LOWY_HIGHY, par->yDim);
                sst_set_bits(FBZMODE, EN_CLIPPING | EN_RGB_WRITE);
        } else {
                /* no clipping : direct access, no pipeline */
                sst_write(LFBMODE, lfbmode);
        }
        return 0;
}

/**
 *      sstfb_setcolreg - Optional function. Sets a color register.
 *      @regno: hardware colormap register
 *      @red: frame buffer colormap structure
 *      @green: The green value which can be up to 16 bits wide
 *      @blue:  The blue value which can be up to 16 bits wide.
 *      @transp: If supported the alpha value which can be up to 16 bits wide.
 *      @info: frame buffer info structure
 */
static int sstfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                           u_int transp, struct fb_info *info)
{
        u32 col;

        f_dddprintk("sstfb_setcolreg\n");
        f_dddprintk("%-2d rgbt: %#x, %#x, %#x, %#x\n",
                    regno, red, green, blue, transp);
        if (regno >= 16)
                return -EINVAL;

        red    >>= (16 - info->var.red.length);
        green  >>= (16 - info->var.green.length);
        blue   >>= (16 - info->var.blue.length);
        transp >>= (16 - info->var.transp.length);
        col = (red << info->var.red.offset)
            | (green << info->var.green.offset)
            | (blue  << info->var.blue.offset)
            | (transp << info->var.transp.offset);
        
        ((u32 *)info->pseudo_palette)[regno] = col;

        return 0;
}

static int sstfb_ioctl(struct inode *inode, struct file *file,
                       u_int cmd, u_long arg, struct fb_info *info )
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        struct pci_dev *sst_dev = par->dev;
        u32 fbiinit0, tmp, val;
        u_long p;

        switch (cmd) {
                
        /* dump current FBIINIT values to system log */
        case _IO('F', 0xdb):            /* 0x46db */
                return sstfb_dump_regs(info);
                
        /* fills lfb with #arg pixels */
        case _IOW('F', 0xdc, u32):      /* 0x46dc */
                if (copy_from_user(&val, (void __user *)arg, sizeof(val)))
                        return -EFAULT;
                if (val > info->fix.smem_len)
                        val = info->fix.smem_len;
                printk("filling %#x \n", val);
                for (p=0 ; p<val; p+=2)
                        writew(p >> 6, info->screen_base + p);
                return 0;
                
        /* change VGA pass_through mode */
        case _IOW('F', 0xdd, u32):      /* 0x46dd */
                if (copy_from_user(&val, (void __user *)arg, sizeof(val)))
                        return -EFAULT;
                pci_read_config_dword(sst_dev, PCI_INIT_ENABLE, &tmp);
                pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
                                       tmp | PCI_EN_INIT_WR );
                fbiinit0 = sst_read (FBIINIT0);
                if (val) {
                        sst_write(FBIINIT0, fbiinit0 & ~EN_VGA_PASSTHROUGH);
                        iprintk("Disabling VGA pass-through\n");
                } else {
                        sst_write(FBIINIT0, fbiinit0 | EN_VGA_PASSTHROUGH);
                        iprintk("Enabling VGA pass-through\n");
                }
                pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, tmp);
                return 0;
                
        /* draw test image  */
        case _IO('F', 0xde):            /* 0x46de */
                f_dprintk("test color display at %d bpp\n",
                                        info->var.bits_per_pixel);
                sstfb_drawdebugimage(info);
                return 0;
        }
        return -EINVAL;
}


/*
 * Screen-to-Screen BitBlt 2D command (for the bmove fb op.) - Voodoo2 only
 */
#if 0
static void sstfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u32 stride = info->fix.line_length;
   
        if (!IS_VOODOO2(par))
                return;

        sst_write(BLTSRCBASEADDR, 0);
        sst_write(BLTDSTBASEADDR, 0);
        sst_write(BLTROP, BLTROP_COPY);
        sst_write(BLTXYSTRIDES, stride | (stride << 16));
        sst_write(BLTSRCXY, area->sx | (area->sy << 16));
        sst_write(BLTDSTXY, area->dx | (area->dy << 16));
        sst_write(BLTSIZE, area->width | (area->height << 16));
        sst_write(BLTCOMMAND, BLT_SCR2SCR_BITBLT | LAUNCH_BITBLT |
                (BLT_16BPP_FMT << 3) /* | BIT(14) */ | BIT(15) );
        sst_wait_idle();
}
#endif


/*
 * FillRect 2D command (solidfill or invert (via ROP_XOR)) - Voodoo2 only
 */
static void sstfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect) 
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u32 stride = info->fix.line_length;

        if (!IS_VOODOO2(par))
                return;
        
        sst_write(BLTCLIPX, info->var.xres);
        sst_write(BLTCLIPY, info->var.yres);
        
        sst_write(BLTDSTBASEADDR, 0);
        sst_write(BLTCOLOR, rect->color);
        sst_write(BLTROP, rect->rop == ROP_COPY ? BLTROP_COPY : BLTROP_XOR);
        sst_write(BLTXYSTRIDES, stride | (stride << 16));
        sst_write(BLTDSTXY, rect->dx | (rect->dy << 16));
        sst_write(BLTSIZE, rect->width | (rect->height << 16));
        sst_write(BLTCOMMAND, BLT_RECFILL_BITBLT | LAUNCH_BITBLT
                 | (BLT_16BPP_FMT << 3) /* | BIT(14) */ | BIT(15) | BIT(16) );
        sst_wait_idle();
}



/* 
 * get lfb size 
 */
static int __devinit sst_get_memsize(struct fb_info *info, __u32 *memsize)
{
        u8 __iomem *fbbase_virt = info->screen_base;

        /* force memsize */
        if ((mem >= 1 ) &&  (mem <= 4)) {
                *memsize = (mem * 0x100000);
                iprintk("supplied memsize: %#x\n", *memsize);
                return 1;
        }

        writel(0xdeadbeef, fbbase_virt);
        writel(0xdeadbeef, fbbase_virt+0x100000);
        writel(0xdeadbeef, fbbase_virt+0x200000);
        f_ddprintk("0MB: %#x, 1MB: %#x, 2MB: %#x\n",
                   readl(fbbase_virt), readl(fbbase_virt + 0x100000),
                   readl(fbbase_virt + 0x200000));

        writel(0xabcdef01, fbbase_virt);

        f_ddprintk("0MB: %#x, 1MB: %#x, 2MB: %#x\n",
                   readl(fbbase_virt), readl(fbbase_virt + 0x100000),
                   readl(fbbase_virt + 0x200000));

        /* checks for 4mb lfb, then 2, then defaults to 1 */
        if (readl(fbbase_virt + 0x200000) == 0xdeadbeef)
                *memsize = 0x400000;
        else if (readl(fbbase_virt + 0x100000) == 0xdeadbeef)
                *memsize = 0x200000;
        else
                *memsize = 0x100000;
        f_ddprintk("detected memsize: %dMB\n", *memsize >> 20);
        return 1;
}


/* 
 * DAC detection routines 
 */

/* fbi should be idle, and fifo emty and mem disabled */
/* supposed to detect AT&T ATT20C409 and Ti TVP3409 ramdacs */

static int __devinit sst_detect_att(struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        int i, mir, dir;

        for (i=0; i<3; i++) {
                sst_dac_write(DACREG_WMA, 0);   /* backdoor */
                sst_dac_read(DACREG_RMR);       /* read 4 times RMR */
                sst_dac_read(DACREG_RMR);
                sst_dac_read(DACREG_RMR);
                sst_dac_read(DACREG_RMR);
                /* the fifth time,  CR0 is read */
                sst_dac_read(DACREG_RMR);
                /* the 6th, manufacturer id register */
                mir = sst_dac_read(DACREG_RMR);
                /*the 7th, device ID register */
                dir = sst_dac_read(DACREG_RMR);
                f_ddprintk("mir: %#x, dir: %#x\n", mir, dir);
                if ((mir == DACREG_MIR_ATT ) && (dir == DACREG_DIR_ATT)) {
                        return 1;
                }
        }
        return 0;
}

static int __devinit sst_detect_ti(struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        int i, mir, dir;

        for (i = 0; i<3; i++) {
                sst_dac_write(DACREG_WMA, 0);   /* backdoor */
                sst_dac_read(DACREG_RMR);       /* read 4 times RMR */
                sst_dac_read(DACREG_RMR);
                sst_dac_read(DACREG_RMR);
                sst_dac_read(DACREG_RMR);
                /* the fifth time,  CR0 is read */
                sst_dac_read(DACREG_RMR);
                /* the 6th, manufacturer id register */
                mir = sst_dac_read(DACREG_RMR);
                /*the 7th, device ID register */
                dir = sst_dac_read(DACREG_RMR);
                f_ddprintk("mir: %#x, dir: %#x\n", mir, dir);
                if ((mir == DACREG_MIR_TI ) && (dir == DACREG_DIR_TI)) {
                        return 1;
                }
        }
        return 0;
}

/*
 * try to detect ICS5342  ramdac
 * we get the 1st byte (M value) of preset f1,f7 and fB
 * why those 3 ? mmmh... for now, i'll do it the glide way...
 * and ask questions later. anyway, it seems that all the freq registers are
 * realy at their default state (cf specs) so i ask again, why those 3 regs ?
 * mmmmh.. it seems that's much more ugly than i thought. we use f0 and fA for
 * pll programming, so in fact, we *hope* that the f1, f7 & fB won't be
 * touched...
 * is it realy safe ? how can i reset this ramdac ? geee...
 */
static int __devinit sst_detect_ics(struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        int m_clk0_1, m_clk0_7, m_clk1_b;
        int n_clk0_1, n_clk0_7, n_clk1_b;
        int i;

        for (i = 0; i<5; i++ ) {
                sst_dac_write(DACREG_ICS_PLLRMA, 0x1);  /* f1 */
                m_clk0_1 = sst_dac_read(DACREG_ICS_PLLDATA);
                n_clk0_1 = sst_dac_read(DACREG_ICS_PLLDATA);
                sst_dac_write(DACREG_ICS_PLLRMA, 0x7);  /* f7 */
                m_clk0_7 = sst_dac_read(DACREG_ICS_PLLDATA);
                n_clk0_7 = sst_dac_read(DACREG_ICS_PLLDATA);
                sst_dac_write(DACREG_ICS_PLLRMA, 0xb);  /* fB */
                m_clk1_b= sst_dac_read(DACREG_ICS_PLLDATA);
                n_clk1_b= sst_dac_read(DACREG_ICS_PLLDATA);
                f_ddprintk("m_clk0_1: %#x, m_clk0_7: %#x, m_clk1_b: %#x\n",
                        m_clk0_1, m_clk0_7, m_clk1_b);
                f_ddprintk("n_clk0_1: %#x, n_clk0_7: %#x, n_clk1_b: %#x\n",
                        n_clk0_1, n_clk0_7, n_clk1_b);
                if ((   m_clk0_1 == DACREG_ICS_PLL_CLK0_1_INI)
                    && (m_clk0_7 == DACREG_ICS_PLL_CLK0_7_INI)
                    && (m_clk1_b == DACREG_ICS_PLL_CLK1_B_INI)) {
                        return 1;
                }
        }
        return 0;
}


/*
 * gfx, video, pci fifo should be reset, dram refresh disabled
 * see detect_dac
 */

static int sst_set_pll_att_ti(struct fb_info *info, 
                const struct pll_timing *t, const int clock)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u8 cr0, cc;

        /* enable indexed mode */
        sst_dac_write(DACREG_WMA, 0);   /* backdoor */
        sst_dac_read(DACREG_RMR);       /* 1 time:  RMR */
        sst_dac_read(DACREG_RMR);       /* 2 RMR */
        sst_dac_read(DACREG_RMR);       /* 3 //  */
        sst_dac_read(DACREG_RMR);       /* 4 //  */
        cr0 = sst_dac_read(DACREG_RMR); /* 5 CR0 */

        sst_dac_write(DACREG_WMA, 0);
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        sst_dac_write(DACREG_RMR, (cr0 & 0xf0)
                      | DACREG_CR0_EN_INDEXED
                      | DACREG_CR0_8BIT
                      | DACREG_CR0_PWDOWN );
        /* so, now we are in indexed mode . dunno if its common, but
           i find this way of doing things a little bit weird :p */

        udelay(300);
        cc = dac_i_read(DACREG_CC_I);
        switch (clock) {
        case VID_CLOCK:
                dac_i_write(DACREG_AC0_I, t->m);
                dac_i_write(DACREG_AC1_I, t->p << 6 | t->n);
                dac_i_write(DACREG_CC_I,
                            (cc & 0x0f) | DACREG_CC_CLKA | DACREG_CC_CLKA_C);
                break;
        case GFX_CLOCK:
                dac_i_write(DACREG_BD0_I, t->m);
                dac_i_write(DACREG_BD1_I, t->p << 6 | t->n);
                dac_i_write(DACREG_CC_I,
                            (cc & 0xf0) | DACREG_CC_CLKB | DACREG_CC_CLKB_D);
                break;
        default:
                dprintk("%s: wrong clock code '%d'\n",
                        __FUNCTION__, clock);
                return 0;
                }
        udelay(300);

        /* power up the dac & return to "normal" non-indexed mode */
        dac_i_write(DACREG_CR0_I,
                    cr0 & ~DACREG_CR0_PWDOWN & ~DACREG_CR0_EN_INDEXED);
        return 1;
}

static int sst_set_pll_ics(struct fb_info *info,
                const struct pll_timing *t, const int clock)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u8 pll_ctrl;

        sst_dac_write(DACREG_ICS_PLLRMA, DACREG_ICS_PLL_CTRL);
        pll_ctrl = sst_dac_read(DACREG_ICS_PLLDATA);
        switch(clock) {
        case VID_CLOCK:
                sst_dac_write(DACREG_ICS_PLLWMA, 0x0);  /* CLK0, f0 */
                sst_dac_write(DACREG_ICS_PLLDATA, t->m);
                sst_dac_write(DACREG_ICS_PLLDATA, t->p << 5 | t->n);
                /* selects freq f0 for clock 0 */
                sst_dac_write(DACREG_ICS_PLLWMA, DACREG_ICS_PLL_CTRL);
                sst_dac_write(DACREG_ICS_PLLDATA,
                              (pll_ctrl & 0xd8)
                              | DACREG_ICS_CLK0
                              | DACREG_ICS_CLK0_0);
                break;
        case GFX_CLOCK :
                sst_dac_write(DACREG_ICS_PLLWMA, 0xa);  /* CLK1, fA */
                sst_dac_write(DACREG_ICS_PLLDATA, t->m);
                sst_dac_write(DACREG_ICS_PLLDATA, t->p << 5 | t->n);
                /* selects freq fA for clock 1 */
                sst_dac_write(DACREG_ICS_PLLWMA, DACREG_ICS_PLL_CTRL);
                sst_dac_write(DACREG_ICS_PLLDATA,
                              (pll_ctrl & 0xef) | DACREG_ICS_CLK1_A);
                break;
        default:
                dprintk("%s: wrong clock code '%d'\n",
                        __FUNCTION__, clock);
                return 0;
                }
        udelay(300);
        return 1;
}

static void sst_set_vidmod_att_ti(struct fb_info *info, const int bpp)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        u8 cr0;

        sst_dac_write(DACREG_WMA, 0);   /* backdoor */
        sst_dac_read(DACREG_RMR);       /* read 4 times RMR */
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        /* the fifth time,  CR0 is read */
        cr0 = sst_dac_read(DACREG_RMR);

        sst_dac_write(DACREG_WMA, 0);   /* backdoor */
        sst_dac_read(DACREG_RMR);       /* read 4 times RMR */
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        sst_dac_read(DACREG_RMR);
        /* cr0 */
        switch(bpp) {
        case 16:
                sst_dac_write(DACREG_RMR, (cr0 & 0x0f) | DACREG_CR0_16BPP);
                break;
#ifdef EN_24_32_BPP
        case 24:
        case 32:
                sst_dac_write(DACREG_RMR, (cr0 & 0x0f) | DACREG_CR0_24BPP);
                break;
#endif
        default:
                dprintk("%s: bad depth '%u'\n", __FUNCTION__, bpp);
                break;
        }
}

static void sst_set_vidmod_ics(struct fb_info *info, const int bpp)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;

        switch(bpp) {
        case 16:
                sst_dac_write(DACREG_ICS_CMD, DACREG_ICS_CMD_16BPP);
                break;
#ifdef EN_24_32_BPP
        case 24:
        case 32:
                sst_dac_write(DACREG_ICS_CMD, DACREG_ICS_CMD_24BPP);
                break;
#endif
        default:
                dprintk("%s: bad depth '%u'\n", __FUNCTION__, bpp);
                break;
        }
}

/*
 * detect dac type
 * prerequisite : write to FbiInitx enabled, video and fbi and pci fifo reset,
 * dram refresh disabled, FbiInit remaped.
 * TODO: mmh.. maybe i shoud put the "prerequisite" in the func ...
 */


static struct dac_switch dacs[] __devinitdata = {
        {       .name           = "TI TVP3409",
                .detect         = sst_detect_ti,
                .set_pll        = sst_set_pll_att_ti,
                .set_vidmod     = sst_set_vidmod_att_ti },

        {       .name           = "AT&T ATT20C409",
                .detect         = sst_detect_att,
                .set_pll        = sst_set_pll_att_ti,
                .set_vidmod     = sst_set_vidmod_att_ti },
        {       .name           = "ICS ICS5342",
                .detect         = sst_detect_ics,
                .set_pll        = sst_set_pll_ics,
                .set_vidmod     = sst_set_vidmod_ics },
};

static int __devinit sst_detect_dactype(struct fb_info *info, struct sstfb_par *par)
{
        int i, ret = 0;
        
        for (i=0; i<sizeof(dacs)/sizeof(dacs[0]); i++) {
                ret = dacs[i].detect(info);
                if (ret) break;
        }
        if (!ret)
                return 0;
        f_dprintk("%s found %s\n", __FUNCTION__, dacs[i].name);
        par->dac_sw = dacs[i];
        return 1;
}

/*
 * Internal Routines
 */
static int __devinit sst_init(struct fb_info *info, struct sstfb_par *par)
{
        u32 fbiinit0, fbiinit1, fbiinit4;
        struct pci_dev *dev = par->dev;
        struct pll_timing gfx_timings;
        struct sst_spec *spec;
        int Fout;

        spec = &voodoo_spec[par->type];
        f_ddprintk(" fbiinit0   fbiinit1   fbiinit2   fbiinit3   fbiinit4  "
                   " fbiinit6\n");
        f_ddprintk("%0#10x %0#10x %0#10x %0#10x %0#10x %0#10x\n",
                    sst_read(FBIINIT0), sst_read(FBIINIT1), sst_read(FBIINIT2),
                    sst_read(FBIINIT3), sst_read(FBIINIT4), sst_read(FBIINIT6));
        /* disable video clock */
        pci_write_config_dword(dev, PCI_VCLK_DISABLE, 0);

        /* enable writing to init registers, disable pci fifo */
        pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
        /* reset video */
        sst_set_bits(FBIINIT1, VIDEO_RESET);
        sst_wait_idle();
        /* reset gfx + pci fifo */
        sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
        sst_wait_idle();

        /* unreset fifo */
        /*sst_unset_bits(FBIINIT0, FIFO_RESET);
        sst_wait_idle();*/
        /* unreset FBI */
        /*sst_unset_bits(FBIINIT0, FBI_RESET);
        sst_wait_idle();*/

        /* disable dram refresh */
        sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
        sst_wait_idle();
        /* remap fbinit2/3 to dac */
        pci_write_config_dword(dev, PCI_INIT_ENABLE,
                                PCI_EN_INIT_WR | PCI_REMAP_DAC );
        /* detect dac type */
        if (!sst_detect_dactype(info, par)) {
                eprintk("Unknown dac type\n");
                //FIXME watch it: we are not in a safe state, bad bad bad.
                return 0;
        }

        /* set graphic clock */
        par->gfx_clock = spec->default_gfx_clock;
        if ((gfxclk >10 ) && (gfxclk < spec->max_gfxclk)) {
                iprintk("Using supplied graphic freq : %dMHz\n", gfxclk);
                 par->gfx_clock = gfxclk *1000;
        } else if (gfxclk) {
                wprintk ("%dMhz is way out of spec! Using default\n", gfxclk);
        }

        sst_calc_pll(par->gfx_clock, &Fout, &gfx_timings);
        par->dac_sw.set_pll(info, &gfx_timings, GFX_CLOCK);

        /* disable fbiinit remap */
        pci_write_config_dword(dev, PCI_INIT_ENABLE,
                               PCI_EN_INIT_WR| PCI_EN_FIFO_WR );
        /* defaults init registers */
        /* FbiInit0: unreset gfx, unreset fifo */
        fbiinit0 = FBIINIT0_DEFAULT;
        fbiinit1 = FBIINIT1_DEFAULT;
        fbiinit4 = FBIINIT4_DEFAULT;
        if (vgapass)
                fbiinit0 &= ~EN_VGA_PASSTHROUGH;
        else
                fbiinit0 |= EN_VGA_PASSTHROUGH;
        if (slowpci) {
                fbiinit1 |= SLOW_PCI_WRITES;
                fbiinit4 |= SLOW_PCI_READS;
        } else {
                fbiinit1 &= ~SLOW_PCI_WRITES;
                fbiinit4 &= ~SLOW_PCI_READS;
        }
        sst_write(FBIINIT0, fbiinit0);
        sst_wait_idle();
        sst_write(FBIINIT1, fbiinit1);
        sst_wait_idle();
        sst_write(FBIINIT2, FBIINIT2_DEFAULT);
        sst_wait_idle();
        sst_write(FBIINIT3, FBIINIT3_DEFAULT);
        sst_wait_idle();
        sst_write(FBIINIT4, fbiinit4);
        sst_wait_idle();
        if (IS_VOODOO2(par)) {
                sst_write(FBIINIT6, FBIINIT6_DEFAULT);
                sst_wait_idle();
        }

        pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_FIFO_WR);
        pci_write_config_dword(dev, PCI_VCLK_ENABLE, 0);
        return 1;
}

static void  __devexit sst_shutdown(struct fb_info *info)
{
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        struct pci_dev *dev = par->dev;
        struct pll_timing gfx_timings;
        int Fout;

        /* reset video, gfx, fifo, disable dram + remap fbiinit2/3 */
        pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
        sst_set_bits(FBIINIT1, VIDEO_RESET | EN_BLANKING);
        sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
        sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
        sst_wait_idle();
        pci_write_config_dword(dev, PCI_INIT_ENABLE,
                               PCI_EN_INIT_WR | PCI_REMAP_DAC);
        /* set 20Mhz gfx clock */
        sst_calc_pll(20000, &Fout, &gfx_timings);
        par->dac_sw.set_pll(info, &gfx_timings, GFX_CLOCK);
        /* TODO maybe shutdown the dac, vrefresh and so on... */
        pci_write_config_dword(dev, PCI_INIT_ENABLE,
                               PCI_EN_INIT_WR);
        sst_unset_bits(FBIINIT0, FBI_RESET | FIFO_RESET | EN_VGA_PASSTHROUGH);
        pci_write_config_dword(dev, PCI_VCLK_DISABLE,0);
        /* maybe keep fbiinit* and PCI_INIT_enable in the fb_info struct
         * from start ? */
        pci_write_config_dword(dev, PCI_INIT_ENABLE, 0);

}

/*
 * Interface to the world
 */
#ifndef MODULE
static int  __init sstfb_setup(char *options)
{
        char *this_opt;

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

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

                f_ddprintk("option %s\n", this_opt);

                if (!strcmp(this_opt, "vganopass"))
                        vgapass = 0;
                else if (!strcmp(this_opt, "vgapass"))
                        vgapass = 1;
                else if (!strcmp(this_opt, "clipping"))
                        clipping = 1;
                else if (!strcmp(this_opt, "noclipping"))
                        clipping = 0;
                else if (!strcmp(this_opt, "fastpci"))
                        slowpci = 0;
                else if (!strcmp(this_opt, "slowpci"))
                        slowpci = 1;
                else if (!strncmp(this_opt, "mem:",4))
                        mem = simple_strtoul (this_opt+4, NULL, 0);
                else if (!strncmp(this_opt, "gfxclk:",7))
                        gfxclk = simple_strtoul (this_opt+7, NULL, 0);
                else
                        mode_option = this_opt;
        }
        return 0;
}
#endif

static struct fb_ops sstfb_ops = {
        .owner          = THIS_MODULE,
        .fb_check_var   = sstfb_check_var,
        .fb_set_par     = sstfb_set_par,
        .fb_setcolreg   = sstfb_setcolreg,
        .fb_fillrect    = cfb_fillrect, /* sstfb_fillrect */
        .fb_copyarea    = cfb_copyarea, /* sstfb_copyarea */
        .fb_imageblit   = cfb_imageblit,
        .fb_cursor      = soft_cursor,
        .fb_ioctl       = sstfb_ioctl,
};

static int __devinit sstfb_probe(struct pci_dev *pdev,
                        const struct pci_device_id *id)
{
        struct fb_info *info;
        struct fb_fix_screeninfo *fix;
        struct sstfb_par *par;
        struct sst_spec *spec;
        int err;

        struct all_info {
                struct fb_info info;
                struct sstfb_par par;
                u32 pseudo_palette[16];
        } *all;
        
        /* Enable device in PCI config. */
        if ((err=pci_enable_device(pdev))) {
                eprintk("cannot enable device\n");
                return err;
        }

        /* Allocate the fb and par structures.  */
        all = kmalloc(sizeof(*all), GFP_KERNEL);
        if (!all)
                return -ENOMEM;
        memset(all, 0, sizeof(*all));
        pci_set_drvdata(pdev, all);
        
        info = &all->info;
        par  = info->par = &all->par;
        fix  = &info->fix;
        
        par->type = id->driver_data;
        spec = &voodoo_spec[par->type];
        f_ddprintk("found device : %s\n", spec->name);

        par->dev = pdev;
        pci_read_config_byte(pdev, PCI_REVISION_ID, &par->revision);

        fix->mmio_start = pci_resource_start(pdev,0);
        fix->mmio_len   = 0x400000;
        fix->smem_start = fix->mmio_start + 0x400000;

        if (!request_mem_region(fix->mmio_start, fix->mmio_len, "sstfb MMIO")) {
                eprintk("cannot reserve mmio memory\n");
                goto fail_mmio_mem;
        }

        if (!request_mem_region(fix->smem_start, 0x400000,"sstfb FB")) {
                eprintk("cannot reserve fb memory\n");
                goto fail_fb_mem;
        }

        par->mmio_vbase = ioremap_nocache(fix->mmio_start,
                                        fix->mmio_len);
        if (!par->mmio_vbase) {
                eprintk("cannot remap register area %#lx\n",
                        fix->mmio_start);
                goto fail_mmio_remap;
        }
        info->screen_base = ioremap_nocache(fix->smem_start, 0x400000);
        if (!info->screen_base) {
                eprintk("cannot remap framebuffer %#lx\n",
                        fix->smem_start);
                goto fail_fb_remap;
        }

        if (!sst_init(info, par)) {
                eprintk("Init failed\n");
                goto fail;
        }
        sst_get_memsize(info, &fix->smem_len);
        strlcpy(fix->id, spec->name, sizeof(fix->id));

        iprintk("%s (revision %d) with %s dac\n",
                fix->id, par->revision, par->dac_sw.name);
        iprintk("framebuffer at %#lx, mapped to 0x%p, size %dMB\n",
                fix->smem_start, info->screen_base,
                fix->smem_len >> 20);

        f_ddprintk("regbase_virt: %#lx\n", par->mmio_vbase);
        f_ddprintk("membase_phys: %#lx\n", fix->smem_start);
        f_ddprintk("fbbase_virt: %p\n", info->screen_base);

        info->flags     = FBINFO_DEFAULT;
        info->fbops     = &sstfb_ops;
        info->pseudo_palette = &all->pseudo_palette;

        fix->type       = FB_TYPE_PACKED_PIXELS;
        fix->visual     = FB_VISUAL_TRUECOLOR;
        fix->accel      = FB_ACCEL_NONE;  /* FIXME */
        /*
         * According to the specs, the linelength must be of 1024 *pixels*
         * and the 24bpp mode is in fact a 32 bpp mode.
         */
        fix->line_length = 2048; /* default value, for 24 or 32bit: 4096 */
        
        if ( mode_option &&
             fb_find_mode(&info->var, info, mode_option, NULL, 0, NULL, 16)) {
                eprintk("can't set supplied video mode. Using default\n");
                info->var = sstfb_default;
        } else
                info->var = sstfb_default;

        if (sstfb_check_var(&info->var, info)) {
                eprintk("invalid default video mode.\n");
                goto fail;
        }

        if (sstfb_set_par(info)) {
                eprintk("can't set default video mode.\n");
                goto fail;
        }
        
        fb_alloc_cmap(&info->cmap, 256, 0);

        /* register fb */
        info->device = &pdev->dev;
        if (register_framebuffer(info) < 0) {
                eprintk("can't register framebuffer.\n");
                goto fail;
        }

        if (1) /* set to 0 to see an initial bitmap instead */
                sstfb_clear_screen(info);
        else
                sstfb_drawdebugimage(info);

        printk(KERN_INFO "fb%d: %s frame buffer device at 0x%p\n",
               info->node, fix->id, info->screen_base);

        return 0;

fail:
        iounmap(info->screen_base);
fail_fb_remap:
        iounmap(par->mmio_vbase);
fail_mmio_remap:
        release_mem_region(fix->smem_start, 0x400000);
fail_fb_mem:
        release_mem_region(fix->mmio_start, info->fix.mmio_len);
fail_mmio_mem:
        kfree(info);
        return -ENXIO;  /* no voodoo detected */
}

static void __devexit sstfb_remove(struct pci_dev *pdev)
{
        struct sstfb_par *par;
        struct fb_info *info;

        info = pci_get_drvdata(pdev);
        par = (struct sstfb_par *) info->par;
        
        sst_shutdown(info);
        unregister_framebuffer(info);
        iounmap(info->screen_base);
        iounmap(par->mmio_vbase);
        release_mem_region(info->fix.smem_start, 0x400000);
        release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
        kfree(info);
}


static struct pci_device_id sstfb_id_tbl[] = {
        { PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_VOODOO1 },
        { PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO2,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, ID_VOODOO2 },
        { 0 },
};

static struct pci_driver sstfb_driver = {
        .name           = "sstfb",
        .id_table       = sstfb_id_tbl,
        .probe          = sstfb_probe,
        .remove         = __devexit_p(sstfb_remove),
};


static int __devinit sstfb_init(void)
{
#ifndef MODULE
        char *option = NULL;

        if (fb_get_options("sstfb", &option))
                return -ENODEV;
        sstfb_setup(option);
#endif
        return pci_register_driver(&sstfb_driver);
}

#ifdef MODULE
static void __devexit sstfb_exit(void)
{
        pci_unregister_driver(&sstfb_driver);
}
#endif


/*
 * testing and debugging functions
 */

static int sstfb_dump_regs(struct fb_info *info)
{
#ifdef SST_DEBUG
        static struct { u32 reg ; const char *reg_name;}  pci_regs[] = {
                { PCI_INIT_ENABLE, "initenable"},
                { PCI_VCLK_ENABLE, "enable vclk"},
                { PCI_VCLK_DISABLE, "disable vclk"},
        };

        static struct { u32 reg ; const char *reg_name;}  sst_regs[] = {
                {FBIINIT0,"fbiinit0"},
                {FBIINIT1,"fbiinit1"},
                {FBIINIT2,"fbiinit2"},
                {FBIINIT3,"fbiinit3"},
                {FBIINIT4,"fbiinit4"},
                {FBIINIT5,"fbiinit5"},
                {FBIINIT6,"fbiinit6"},
                {FBIINIT7,"fbiinit7"},
                {LFBMODE,"lfbmode"},
                {FBZMODE,"fbzmode"},
        };

        const int pci_s = sizeof(pci_regs)/sizeof(pci_regs[0]);
        const int sst_s = sizeof(sst_regs)/sizeof(sst_regs[0]);
        struct sstfb_par *par = (struct sstfb_par *) info->par;
        struct pci_dev *dev = par->dev;
        u32 pci_res[pci_s];
        u32 sst_res[sst_s];
        int i;

        for (i=0; i<pci_s; i++) {
                pci_read_config_dword(dev, pci_regs[i].reg, &pci_res[i]);
        }
        for (i=0; i<sst_s; i++) {
                sst_res[i] = sst_read(sst_regs[i].reg);
        }

        dprintk("hardware register dump:\n");
        for (i=0; i<pci_s; i++) {
                dprintk("%s %0#10x\n", pci_regs[i].reg_name, pci_res[i]);
        }
        for (i=0; i<sst_s; i++) {
                dprintk("%s %0#10x\n", sst_regs[i].reg_name, sst_res[i]);
        }
        return 0;
#else
        return -EINVAL;
#endif
}

static void sstfb_fillrect_softw( struct fb_info *info, const struct fb_fillrect *rect)
{
        u8 __iomem *fbbase_virt = info->screen_base;
        int x, y, w = info->var.bits_per_pixel == 16 ? 2 : 4;
        u32 color = rect->color, height = rect->height;
        u8 __iomem *p;
        
        if (w==2) color |= color<<16;
        for (y=rect->dy; height; y++, height--) {
                p = fbbase_virt + y*info->fix.line_length + rect->dx*w;
                x = rect->width;
                if (w==2) x>>=1;
                while (x) {
                        writel(color, p);
                        p += 4;
                        x--;
                }
        }
}

static void sstfb_drawrect_XY( struct fb_info *info, int x, int y,
                int w, int h, int color, int hwfunc)
{
        struct fb_fillrect rect;
        rect.dx = x;
        rect.dy = y;
        rect.height = h;
        rect.width = w;
        rect.color = color;
        rect.rop = ROP_COPY;
        if (hwfunc)
                sstfb_fillrect(info, &rect);
        else
                sstfb_fillrect_softw(info, &rect);
}

/* print some squares on the fb */
static void sstfb_drawdebugimage(struct fb_info *info)
{
        static int idx;

        /* clear screen */
        sstfb_clear_screen(info);
        
        idx = (idx+1) & 1;

        /* white rect */
        sstfb_drawrect_XY(info, 0, 0, 50, 50, 0xffff, idx);
        
        /* blue rect */
        sstfb_drawrect_XY(info, 50, 50, 50, 50, 0x001f, idx);

        /* green rect */
        sstfb_drawrect_XY(info, 100, 100, 80, 80, 0x07e0, idx);
        
        /* red rect */
        sstfb_drawrect_XY(info, 250, 250, 120, 100, 0xf800, idx);
}

module_init(sstfb_init);

#ifdef MODULE
module_exit(sstfb_exit);
#endif

MODULE_AUTHOR("(c) 2000,2002 Ghozlane Toumi <gtoumi@laposte.net>");
MODULE_DESCRIPTION("FBDev driver for 3dfx Voodoo Graphics and Voodoo2 based video boards");
MODULE_LICENSE("GPL");

module_param(mem, int, 0);
MODULE_PARM_DESC(mem, "Size of frame buffer memory in MB (1, 2, 4 MB, default=autodetect)");
module_param(vgapass, bool, 0);
MODULE_PARM_DESC(vgapass, "Enable VGA PassThrough mode (0 or 1) (default=0)");
module_param(clipping, bool, 0);
MODULE_PARM_DESC(clipping, "Enable clipping (slower, safer) (0 or 1) (default=1)");
module_param(gfxclk, int, 0);
MODULE_PARM_DESC(gfxclk, "Force graphic chip frequency in MHz. DANGEROUS. (default=auto)");
module_param(slowpci, bool, 0);
MODULE_PARM_DESC(slowpci, "Uses slow PCI settings (0 or 1) (default=0)");