pciehp: fix NULL dereference in interrupt handler

[linux-2.6/mini2440.git] / drivers / video / arkfb.c

/*
 *  linux/drivers/video/arkfb.c -- Frame buffer device driver for ARK 2000PV
 *  with ICS 5342 dac (it is easy to add support for different dacs).
 *
 *  Copyright (c) 2007 Ondrej Zajicek <santiago@crfreenet.org>
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file COPYING in the main directory of this archive for
 *  more details.
 *
 *  Code is based on s3fb
 */

#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/svga.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/console.h> /* Why should fb driver call console functions? because acquire_console_sem() */
#include <video/vga.h>

#ifdef CONFIG_MTRR
#include <asm/mtrr.h>
#endif

struct arkfb_info {
        int mclk_freq;
        int mtrr_reg;

        struct dac_info *dac;
        struct vgastate state;
        struct mutex open_lock;
        unsigned int ref_count;
        u32 pseudo_palette[16];
};


/* ------------------------------------------------------------------------- */


static const struct svga_fb_format arkfb_formats[] = {
        { 0,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
                FB_TYPE_TEXT, FB_AUX_TEXT_SVGA_STEP4,   FB_VISUAL_PSEUDOCOLOR, 8, 8},
        { 4,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_PSEUDOCOLOR, 8, 16},
        { 4,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 1,
                FB_TYPE_INTERLEAVED_PLANES, 1,          FB_VISUAL_PSEUDOCOLOR, 8, 16},
        { 8,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_PSEUDOCOLOR, 8, 8},
        {16,  {10, 5, 0}, {5, 5, 0},  {0, 5, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_TRUECOLOR, 4, 4},
        {16,  {11, 5, 0}, {5, 6, 0},  {0, 5, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_TRUECOLOR, 4, 4},
        {24,  {16, 8, 0}, {8, 8, 0},  {0, 8, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_TRUECOLOR, 8, 8},
        {32,  {16, 8, 0}, {8, 8, 0},  {0, 8, 0}, {0, 0, 0}, 0,
                FB_TYPE_PACKED_PIXELS, 0,               FB_VISUAL_TRUECOLOR, 2, 2},
        SVGA_FORMAT_END
};


/* CRT timing register sets */

static const struct vga_regset ark_h_total_regs[]        = {{0x00, 0, 7}, {0x41, 7, 7}, VGA_REGSET_END};
static const struct vga_regset ark_h_display_regs[]      = {{0x01, 0, 7}, {0x41, 6, 6}, VGA_REGSET_END};
static const struct vga_regset ark_h_blank_start_regs[]  = {{0x02, 0, 7}, {0x41, 5, 5}, VGA_REGSET_END};
static const struct vga_regset ark_h_blank_end_regs[]    = {{0x03, 0, 4}, {0x05, 7, 7   }, VGA_REGSET_END};
static const struct vga_regset ark_h_sync_start_regs[]   = {{0x04, 0, 7}, {0x41, 4, 4}, VGA_REGSET_END};
static const struct vga_regset ark_h_sync_end_regs[]     = {{0x05, 0, 4}, VGA_REGSET_END};

static const struct vga_regset ark_v_total_regs[]        = {{0x06, 0, 7}, {0x07, 0, 0}, {0x07, 5, 5}, {0x40, 7, 7}, VGA_REGSET_END};
static const struct vga_regset ark_v_display_regs[]      = {{0x12, 0, 7}, {0x07, 1, 1}, {0x07, 6, 6}, {0x40, 6, 6}, VGA_REGSET_END};
static const struct vga_regset ark_v_blank_start_regs[]  = {{0x15, 0, 7}, {0x07, 3, 3}, {0x09, 5, 5}, {0x40, 5, 5}, VGA_REGSET_END};
// const struct vga_regset ark_v_blank_end_regs[]    = {{0x16, 0, 6}, VGA_REGSET_END};
static const struct vga_regset ark_v_blank_end_regs[]    = {{0x16, 0, 7}, VGA_REGSET_END};
static const struct vga_regset ark_v_sync_start_regs[]   = {{0x10, 0, 7}, {0x07, 2, 2}, {0x07, 7, 7}, {0x40, 4, 4}, VGA_REGSET_END};
static const struct vga_regset ark_v_sync_end_regs[]     = {{0x11, 0, 3}, VGA_REGSET_END};

static const struct vga_regset ark_line_compare_regs[]   = {{0x18, 0, 7}, {0x07, 4, 4}, {0x09, 6, 6}, VGA_REGSET_END};
static const struct vga_regset ark_start_address_regs[]  = {{0x0d, 0, 7}, {0x0c, 0, 7}, {0x40, 0, 2}, VGA_REGSET_END};
static const struct vga_regset ark_offset_regs[]         = {{0x13, 0, 7}, {0x41, 3, 3}, VGA_REGSET_END};

static const struct svga_timing_regs ark_timing_regs     = {
        ark_h_total_regs, ark_h_display_regs, ark_h_blank_start_regs,
        ark_h_blank_end_regs, ark_h_sync_start_regs, ark_h_sync_end_regs,
        ark_v_total_regs, ark_v_display_regs, ark_v_blank_start_regs,
        ark_v_blank_end_regs, ark_v_sync_start_regs, ark_v_sync_end_regs,
};


/* ------------------------------------------------------------------------- */


/* Module parameters */

static char *mode_option __devinitdata = "640x480-8@60";

#ifdef CONFIG_MTRR
static int mtrr = 1;
#endif

MODULE_AUTHOR("(c) 2007 Ondrej Zajicek <santiago@crfreenet.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("fbdev driver for ARK 2000PV");

module_param(mode_option, charp, 0444);
MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
module_param_named(mode, mode_option, charp, 0444);
MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)");

#ifdef CONFIG_MTRR
module_param(mtrr, int, 0444);
MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
#endif

static int threshold = 4;

module_param(threshold, int, 0644);
MODULE_PARM_DESC(threshold, "FIFO threshold");


/* ------------------------------------------------------------------------- */


static void arkfb_settile(struct fb_info *info, struct fb_tilemap *map)
{
        const u8 *font = map->data;
        u8 __iomem *fb = (u8 __iomem *)info->screen_base;
        int i, c;

        if ((map->width != 8) || (map->height != 16) ||
            (map->depth != 1) || (map->length != 256)) {
                printk(KERN_ERR "fb%d: unsupported font parameters: width %d, "
                       "height %d, depth %d, length %d\n", info->node,
                       map->width, map->height, map->depth, map->length);
                return;
        }

        fb += 2;
        for (c = 0; c < map->length; c++) {
                for (i = 0; i < map->height; i++) {
                        fb_writeb(font[i], &fb[i * 4]);
                        fb_writeb(font[i], &fb[i * 4 + (128 * 8)]);
                }
                fb += 128;

                if ((c % 8) == 7)
                        fb += 128*8;

                font += map->height;
        }
}

static struct fb_tile_ops arkfb_tile_ops = {
        .fb_settile     = arkfb_settile,
        .fb_tilecopy    = svga_tilecopy,
        .fb_tilefill    = svga_tilefill,
        .fb_tileblit    = svga_tileblit,
        .fb_tilecursor  = svga_tilecursor,
        .fb_get_tilemax = svga_get_tilemax,
};


/* ------------------------------------------------------------------------- */


/* image data is MSB-first, fb structure is MSB-first too */
static inline u32 expand_color(u32 c)
{
        return ((c & 1) | ((c & 2) << 7) | ((c & 4) << 14) | ((c & 8) << 21)) * 0xFF;
}

/* arkfb_iplan_imageblit silently assumes that almost everything is 8-pixel aligned */
static void arkfb_iplan_imageblit(struct fb_info *info, const struct fb_image *image)
{
        u32 fg = expand_color(image->fg_color);
        u32 bg = expand_color(image->bg_color);
        const u8 *src1, *src;
        u8 __iomem *dst1;
        u32 __iomem *dst;
        u32 val;
        int x, y;

        src1 = image->data;
        dst1 = info->screen_base + (image->dy * info->fix.line_length)
                 + ((image->dx / 8) * 4);

        for (y = 0; y < image->height; y++) {
                src = src1;
                dst = (u32 __iomem *) dst1;
                for (x = 0; x < image->width; x += 8) {
                        val = *(src++) * 0x01010101;
                        val = (val & fg) | (~val & bg);
                        fb_writel(val, dst++);
                }
                src1 += image->width / 8;
                dst1 += info->fix.line_length;
        }

}

/* arkfb_iplan_fillrect silently assumes that almost everything is 8-pixel aligned */
static void arkfb_iplan_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        u32 fg = expand_color(rect->color);
        u8 __iomem *dst1;
        u32 __iomem *dst;
        int x, y;

        dst1 = info->screen_base + (rect->dy * info->fix.line_length)
                 + ((rect->dx / 8) * 4);

        for (y = 0; y < rect->height; y++) {
                dst = (u32 __iomem *) dst1;
                for (x = 0; x < rect->width; x += 8) {
                        fb_writel(fg, dst++);
                }
                dst1 += info->fix.line_length;
        }

}


/* image data is MSB-first, fb structure is high-nibble-in-low-byte-first */
static inline u32 expand_pixel(u32 c)
{
        return (((c &  1) << 24) | ((c &  2) << 27) | ((c &  4) << 14) | ((c &   8) << 17) |
                ((c & 16) <<  4) | ((c & 32) <<  7) | ((c & 64) >>  6) | ((c & 128) >>  3)) * 0xF;
}

/* arkfb_cfb4_imageblit silently assumes that almost everything is 8-pixel aligned */
static void arkfb_cfb4_imageblit(struct fb_info *info, const struct fb_image *image)
{
        u32 fg = image->fg_color * 0x11111111;
        u32 bg = image->bg_color * 0x11111111;
        const u8 *src1, *src;
        u8 __iomem *dst1;
        u32 __iomem *dst;
        u32 val;
        int x, y;

        src1 = image->data;
        dst1 = info->screen_base + (image->dy * info->fix.line_length)
                 + ((image->dx / 8) * 4);

        for (y = 0; y < image->height; y++) {
                src = src1;
                dst = (u32 __iomem *) dst1;
                for (x = 0; x < image->width; x += 8) {
                        val = expand_pixel(*(src++));
                        val = (val & fg) | (~val & bg);
                        fb_writel(val, dst++);
                }
                src1 += image->width / 8;
                dst1 += info->fix.line_length;
        }

}

static void arkfb_imageblit(struct fb_info *info, const struct fb_image *image)
{
        if ((info->var.bits_per_pixel == 4) && (image->depth == 1)
            && ((image->width % 8) == 0) && ((image->dx % 8) == 0)) {
                if (info->fix.type == FB_TYPE_INTERLEAVED_PLANES)
                        arkfb_iplan_imageblit(info, image);
                else
                        arkfb_cfb4_imageblit(info, image);
        } else
                cfb_imageblit(info, image);
}

static void arkfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        if ((info->var.bits_per_pixel == 4)
            && ((rect->width % 8) == 0) && ((rect->dx % 8) == 0)
            && (info->fix.type == FB_TYPE_INTERLEAVED_PLANES))
                arkfb_iplan_fillrect(info, rect);
         else
                cfb_fillrect(info, rect);
}


/* ------------------------------------------------------------------------- */


enum
{
        DAC_PSEUDO8_8,
        DAC_RGB1555_8,
        DAC_RGB0565_8,
        DAC_RGB0888_8,
        DAC_RGB8888_8,
        DAC_PSEUDO8_16,
        DAC_RGB1555_16,
        DAC_RGB0565_16,
        DAC_RGB0888_16,
        DAC_RGB8888_16,
        DAC_MAX
};

struct dac_ops {
        int (*dac_get_mode)(struct dac_info *info);
        int (*dac_set_mode)(struct dac_info *info, int mode);
        int (*dac_get_freq)(struct dac_info *info, int channel);
        int (*dac_set_freq)(struct dac_info *info, int channel, u32 freq);
        void (*dac_release)(struct dac_info *info);
};

typedef void (*dac_read_regs_t)(void *data, u8 *code, int count);
typedef void (*dac_write_regs_t)(void *data, u8 *code, int count);

struct dac_info
{
        struct dac_ops *dacops;
        dac_read_regs_t dac_read_regs;
        dac_write_regs_t dac_write_regs;
        void *data;
};


static inline u8 dac_read_reg(struct dac_info *info, u8 reg)
{
        u8 code[2] = {reg, 0};
        info->dac_read_regs(info->data, code, 1);
        return code[1];
}

static inline void dac_read_regs(struct dac_info *info, u8 *code, int count)
{
        info->dac_read_regs(info->data, code, count);
}

static inline void dac_write_reg(struct dac_info *info, u8 reg, u8 val)
{
        u8 code[2] = {reg, val};
        info->dac_write_regs(info->data, code, 1);
}

static inline void dac_write_regs(struct dac_info *info, u8 *code, int count)
{
        info->dac_write_regs(info->data, code, count);
}

static inline int dac_set_mode(struct dac_info *info, int mode)
{
        return info->dacops->dac_set_mode(info, mode);
}

static inline int dac_set_freq(struct dac_info *info, int channel, u32 freq)
{
        return info->dacops->dac_set_freq(info, channel, freq);
}

static inline void dac_release(struct dac_info *info)
{
        info->dacops->dac_release(info);
}


/* ------------------------------------------------------------------------- */


/* ICS5342 DAC */

struct ics5342_info
{
        struct dac_info dac;
        u8 mode;
};

#define DAC_PAR(info) ((struct ics5342_info *) info)

/* LSB is set to distinguish unused slots */
static const u8 ics5342_mode_table[DAC_MAX] = {
        [DAC_PSEUDO8_8]  = 0x01, [DAC_RGB1555_8]  = 0x21, [DAC_RGB0565_8]  = 0x61,
        [DAC_RGB0888_8]  = 0x41, [DAC_PSEUDO8_16] = 0x11, [DAC_RGB1555_16] = 0x31,
        [DAC_RGB0565_16] = 0x51, [DAC_RGB0888_16] = 0x91, [DAC_RGB8888_16] = 0x71
};

static int ics5342_set_mode(struct dac_info *info, int mode)
{
        u8 code;

        if (mode >= DAC_MAX)
                return -EINVAL;

        code = ics5342_mode_table[mode];

        if (! code)
                return -EINVAL;

        dac_write_reg(info, 6, code & 0xF0);
        DAC_PAR(info)->mode = mode;

        return 0;
}

static const struct svga_pll ics5342_pll = {3, 129, 3, 33, 0, 3,
        60000, 250000, 14318};

/* pd4 - allow only posdivider 4 (r=2) */
static const struct svga_pll ics5342_pll_pd4 = {3, 129, 3, 33, 2, 2,
        60000, 335000, 14318};

/* 270 MHz should be upper bound for VCO clock according to specs,
   but that is too restrictive in pd4 case */

static int ics5342_set_freq(struct dac_info *info, int channel, u32 freq)
{
        u16 m, n, r;

        /* only postdivider 4 (r=2) is valid in mode DAC_PSEUDO8_16 */
        int rv = svga_compute_pll((DAC_PAR(info)->mode == DAC_PSEUDO8_16)
                                  ? &ics5342_pll_pd4 : &ics5342_pll,
                                  freq, &m, &n, &r, 0);

        if (rv < 0) {
                return -EINVAL;
        } else {
                u8 code[6] = {4, 3, 5, m-2, 5, (n-2) | (r << 5)};
                dac_write_regs(info, code, 3);
                return 0;
        }
}

static void ics5342_release(struct dac_info *info)
{
        ics5342_set_mode(info, DAC_PSEUDO8_8);
        kfree(info);
}

static struct dac_ops ics5342_ops = {
        .dac_set_mode   = ics5342_set_mode,
        .dac_set_freq   = ics5342_set_freq,
        .dac_release    = ics5342_release
};


static struct dac_info * ics5342_init(dac_read_regs_t drr, dac_write_regs_t dwr, void *data)
{
        struct dac_info *info = kzalloc(sizeof(struct ics5342_info), GFP_KERNEL);

        if (! info)
                return NULL;

        info->dacops = &ics5342_ops;
        info->dac_read_regs = drr;
        info->dac_write_regs = dwr;
        info->data = data;
        DAC_PAR(info)->mode = DAC_PSEUDO8_8; /* estimation */
        return info;
}


/* ------------------------------------------------------------------------- */


static unsigned short dac_regs[4] = {0x3c8, 0x3c9, 0x3c6, 0x3c7};

static void ark_dac_read_regs(void *data, u8 *code, int count)
{
        u8 regval = vga_rseq(NULL, 0x1C);

        while (count != 0)
        {
                vga_wseq(NULL, 0x1C, regval | (code[0] & 4) ? 0x80 : 0);
                code[1] = vga_r(NULL, dac_regs[code[0] & 3]);
                count--;
                code += 2;
        }

        vga_wseq(NULL, 0x1C, regval);
}

static void ark_dac_write_regs(void *data, u8 *code, int count)
{
        u8 regval = vga_rseq(NULL, 0x1C);

        while (count != 0)
        {
                vga_wseq(NULL, 0x1C, regval | (code[0] & 4) ? 0x80 : 0);
                vga_w(NULL, dac_regs[code[0] & 3], code[1]);
                count--;
                code += 2;
        }

        vga_wseq(NULL, 0x1C, regval);
}


static void ark_set_pixclock(struct fb_info *info, u32 pixclock)
{
        struct arkfb_info *par = info->par;
        u8 regval;

        int rv = dac_set_freq(par->dac, 0, 1000000000 / pixclock);
        if (rv < 0) {
                printk(KERN_ERR "fb%d: cannot set requested pixclock, keeping old value\n", info->node);
                return;
        }

        /* Set VGA misc register  */
        regval = vga_r(NULL, VGA_MIS_R);
        vga_w(NULL, VGA_MIS_W, regval | VGA_MIS_ENB_PLL_LOAD);
}


/* Open framebuffer */

static int arkfb_open(struct fb_info *info, int user)
{
        struct arkfb_info *par = info->par;

        mutex_lock(&(par->open_lock));
        if (par->ref_count == 0) {
                memset(&(par->state), 0, sizeof(struct vgastate));
                par->state.flags = VGA_SAVE_MODE | VGA_SAVE_FONTS | VGA_SAVE_CMAP;
                par->state.num_crtc = 0x60;
                par->state.num_seq = 0x30;
                save_vga(&(par->state));
        }

        par->ref_count++;
        mutex_unlock(&(par->open_lock));

        return 0;
}

/* Close framebuffer */

static int arkfb_release(struct fb_info *info, int user)
{
        struct arkfb_info *par = info->par;

        mutex_lock(&(par->open_lock));
        if (par->ref_count == 0) {
                mutex_unlock(&(par->open_lock));
                return -EINVAL;
        }

        if (par->ref_count == 1) {
                restore_vga(&(par->state));
                dac_set_mode(par->dac, DAC_PSEUDO8_8);
        }

        par->ref_count--;
        mutex_unlock(&(par->open_lock));

        return 0;
}

/* Validate passed in var */

static int arkfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        int rv, mem, step;

        /* Find appropriate format */
        rv = svga_match_format (arkfb_formats, var, NULL);
        if (rv < 0)
        {
                printk(KERN_ERR "fb%d: unsupported mode requested\n", info->node);
                return rv;
        }

        /* Do not allow to have real resoulution larger than virtual */
        if (var->xres > var->xres_virtual)
                var->xres_virtual = var->xres;

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

        /* Round up xres_virtual to have proper alignment of lines */
        step = arkfb_formats[rv].xresstep - 1;
        var->xres_virtual = (var->xres_virtual+step) & ~step;


        /* Check whether have enough memory */
        mem = ((var->bits_per_pixel * var->xres_virtual) >> 3) * var->yres_virtual;
        if (mem > info->screen_size)
        {
                printk(KERN_ERR "fb%d: not enough framebuffer memory (%d kB requested , %d kB available)\n", info->node, mem >> 10, (unsigned int) (info->screen_size >> 10));
                return -EINVAL;
        }

        rv = svga_check_timings (&ark_timing_regs, var, info->node);
        if (rv < 0)
        {
                printk(KERN_ERR "fb%d: invalid timings requested\n", info->node);
                return rv;
        }

        /* Interlaced mode is broken */
        if (var->vmode & FB_VMODE_INTERLACED)
                return -EINVAL;

        return 0;
}

/* Set video mode from par */

static int arkfb_set_par(struct fb_info *info)
{
        struct arkfb_info *par = info->par;
        u32 value, mode, hmul, hdiv, offset_value, screen_size;
        u32 bpp = info->var.bits_per_pixel;
        u8 regval;

        if (bpp != 0) {
                info->fix.ypanstep = 1;
                info->fix.line_length = (info->var.xres_virtual * bpp) / 8;

                info->flags &= ~FBINFO_MISC_TILEBLITTING;
                info->tileops = NULL;

                /* in 4bpp supports 8p wide tiles only, any tiles otherwise */
                info->pixmap.blit_x = (bpp == 4) ? (1 << (8 - 1)) : (~(u32)0);
                info->pixmap.blit_y = ~(u32)0;

                offset_value = (info->var.xres_virtual * bpp) / 64;
                screen_size = info->var.yres_virtual * info->fix.line_length;
        } else {
                info->fix.ypanstep = 16;
                info->fix.line_length = 0;

                info->flags |= FBINFO_MISC_TILEBLITTING;
                info->tileops = &arkfb_tile_ops;

                /* supports 8x16 tiles only */
                info->pixmap.blit_x = 1 << (8 - 1);
                info->pixmap.blit_y = 1 << (16 - 1);

                offset_value = info->var.xres_virtual / 16;
                screen_size = (info->var.xres_virtual * info->var.yres_virtual) / 64;
        }

        info->var.xoffset = 0;
        info->var.yoffset = 0;
        info->var.activate = FB_ACTIVATE_NOW;

        /* Unlock registers */
        svga_wcrt_mask(0x11, 0x00, 0x80);

        /* Blank screen and turn off sync */
        svga_wseq_mask(0x01, 0x20, 0x20);
        svga_wcrt_mask(0x17, 0x00, 0x80);

        /* Set default values */
        svga_set_default_gfx_regs();
        svga_set_default_atc_regs();
        svga_set_default_seq_regs();
        svga_set_default_crt_regs();
        svga_wcrt_multi(ark_line_compare_regs, 0xFFFFFFFF);
        svga_wcrt_multi(ark_start_address_regs, 0);

        /* ARK specific initialization */
        svga_wseq_mask(0x10, 0x1F, 0x1F); /* enable linear framebuffer and full memory access */
        svga_wseq_mask(0x12, 0x03, 0x03); /* 4 MB linear framebuffer size */

        vga_wseq(NULL, 0x13, info->fix.smem_start >> 16);
        vga_wseq(NULL, 0x14, info->fix.smem_start >> 24);
        vga_wseq(NULL, 0x15, 0);
        vga_wseq(NULL, 0x16, 0);

        /* Set the FIFO threshold register */
        /* It is fascinating way to store 5-bit value in 8-bit register */
        regval = 0x10 | ((threshold & 0x0E) >> 1) | (threshold & 0x01) << 7 | (threshold & 0x10) << 1;
        vga_wseq(NULL, 0x18, regval);

        /* Set the offset register */
        pr_debug("fb%d: offset register       : %d\n", info->node, offset_value);
        svga_wcrt_multi(ark_offset_regs, offset_value);

        /* fix for hi-res textmode */
        svga_wcrt_mask(0x40, 0x08, 0x08);

        if (info->var.vmode & FB_VMODE_DOUBLE)
                svga_wcrt_mask(0x09, 0x80, 0x80);
        else
                svga_wcrt_mask(0x09, 0x00, 0x80);

        if (info->var.vmode & FB_VMODE_INTERLACED)
                svga_wcrt_mask(0x44, 0x04, 0x04);
        else
                svga_wcrt_mask(0x44, 0x00, 0x04);

        hmul = 1;
        hdiv = 1;
        mode = svga_match_format(arkfb_formats, &(info->var), &(info->fix));

        /* Set mode-specific register values */
        switch (mode) {
        case 0:
                pr_debug("fb%d: text mode\n", info->node);
                svga_set_textmode_vga_regs();

                vga_wseq(NULL, 0x11, 0x10); /* basic VGA mode */
                svga_wcrt_mask(0x46, 0x00, 0x04); /* 8bit pixel path */
                dac_set_mode(par->dac, DAC_PSEUDO8_8);

                break;
        case 1:
                pr_debug("fb%d: 4 bit pseudocolor\n", info->node);
                vga_wgfx(NULL, VGA_GFX_MODE, 0x40);

                vga_wseq(NULL, 0x11, 0x10); /* basic VGA mode */
                svga_wcrt_mask(0x46, 0x00, 0x04); /* 8bit pixel path */
                dac_set_mode(par->dac, DAC_PSEUDO8_8);
                break;
        case 2:
                pr_debug("fb%d: 4 bit pseudocolor, planar\n", info->node);

                vga_wseq(NULL, 0x11, 0x10); /* basic VGA mode */
                svga_wcrt_mask(0x46, 0x00, 0x04); /* 8bit pixel path */
                dac_set_mode(par->dac, DAC_PSEUDO8_8);
                break;
        case 3:
                pr_debug("fb%d: 8 bit pseudocolor\n", info->node);

                vga_wseq(NULL, 0x11, 0x16); /* 8bpp accel mode */

                if (info->var.pixclock > 20000) {
                        pr_debug("fb%d: not using multiplex\n", info->node);
                        svga_wcrt_mask(0x46, 0x00, 0x04); /* 8bit pixel path */
                        dac_set_mode(par->dac, DAC_PSEUDO8_8);
                } else {
                        pr_debug("fb%d: using multiplex\n", info->node);
                        svga_wcrt_mask(0x46, 0x04, 0x04); /* 16bit pixel path */
                        dac_set_mode(par->dac, DAC_PSEUDO8_16);
                        hdiv = 2;
                }
                break;
        case 4:
                pr_debug("fb%d: 5/5/5 truecolor\n", info->node);

                vga_wseq(NULL, 0x11, 0x1A); /* 16bpp accel mode */
                svga_wcrt_mask(0x46, 0x04, 0x04); /* 16bit pixel path */
                dac_set_mode(par->dac, DAC_RGB1555_16);
                break;
        case 5:
                pr_debug("fb%d: 5/6/5 truecolor\n", info->node);

                vga_wseq(NULL, 0x11, 0x1A); /* 16bpp accel mode */
                svga_wcrt_mask(0x46, 0x04, 0x04); /* 16bit pixel path */
                dac_set_mode(par->dac, DAC_RGB0565_16);
                break;
        case 6:
                pr_debug("fb%d: 8/8/8 truecolor\n", info->node);

                vga_wseq(NULL, 0x11, 0x16); /* 8bpp accel mode ??? */
                svga_wcrt_mask(0x46, 0x04, 0x04); /* 16bit pixel path */
                dac_set_mode(par->dac, DAC_RGB0888_16);
                hmul = 3;
                hdiv = 2;
                break;
        case 7:
                pr_debug("fb%d: 8/8/8/8 truecolor\n", info->node);

                vga_wseq(NULL, 0x11, 0x1E); /* 32bpp accel mode */
                svga_wcrt_mask(0x46, 0x04, 0x04); /* 16bit pixel path */
                dac_set_mode(par->dac, DAC_RGB8888_16);
                hmul = 2;
                break;
        default:
                printk(KERN_ERR "fb%d: unsupported mode - bug\n", info->node);
                return -EINVAL;
        }

        ark_set_pixclock(info, (hdiv * info->var.pixclock) / hmul);
        svga_set_timings(&ark_timing_regs, &(info->var), hmul, hdiv,
                         (info->var.vmode & FB_VMODE_DOUBLE)     ? 2 : 1,
                         (info->var.vmode & FB_VMODE_INTERLACED) ? 2 : 1,
                          hmul, info->node);

        /* Set interlaced mode start/end register */
        value = info->var.xres + info->var.left_margin + info->var.right_margin + info->var.hsync_len;
        value = ((value * hmul / hdiv) / 8) - 5;
        vga_wcrt(NULL, 0x42, (value + 1) / 2);

        memset_io(info->screen_base, 0x00, screen_size);
        /* Device and screen back on */
        svga_wcrt_mask(0x17, 0x80, 0x80);
        svga_wseq_mask(0x01, 0x00, 0x20);

        return 0;
}

/* Set a colour register */

static int arkfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                                u_int transp, struct fb_info *fb)
{
        switch (fb->var.bits_per_pixel) {
        case 0:
        case 4:
                if (regno >= 16)
                        return -EINVAL;

                if ((fb->var.bits_per_pixel == 4) &&
                    (fb->var.nonstd == 0)) {
                        outb(0xF0, VGA_PEL_MSK);
                        outb(regno*16, VGA_PEL_IW);
                } else {
                        outb(0x0F, VGA_PEL_MSK);
                        outb(regno, VGA_PEL_IW);
                }
                outb(red >> 10, VGA_PEL_D);
                outb(green >> 10, VGA_PEL_D);
                outb(blue >> 10, VGA_PEL_D);
                break;
        case 8:
                if (regno >= 256)
                        return -EINVAL;

                outb(0xFF, VGA_PEL_MSK);
                outb(regno, VGA_PEL_IW);
                outb(red >> 10, VGA_PEL_D);
                outb(green >> 10, VGA_PEL_D);
                outb(blue >> 10, VGA_PEL_D);
                break;
        case 16:
                if (regno >= 16)
                        return 0;

                if (fb->var.green.length == 5)
                        ((u32*)fb->pseudo_palette)[regno] = ((red & 0xF800) >> 1) |
                                ((green & 0xF800) >> 6) | ((blue & 0xF800) >> 11);
                else if (fb->var.green.length == 6)
                        ((u32*)fb->pseudo_palette)[regno] = (red & 0xF800) |
                                ((green & 0xFC00) >> 5) | ((blue & 0xF800) >> 11);
                else
                        return -EINVAL;
                break;
        case 24:
        case 32:
                if (regno >= 16)
                        return 0;

                ((u32*)fb->pseudo_palette)[regno] = ((red & 0xFF00) << 8) |
                        (green & 0xFF00) | ((blue & 0xFF00) >> 8);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/* Set the display blanking state */

static int arkfb_blank(int blank_mode, struct fb_info *info)
{
        switch (blank_mode) {
        case FB_BLANK_UNBLANK:
                pr_debug("fb%d: unblank\n", info->node);
                svga_wseq_mask(0x01, 0x00, 0x20);
                svga_wcrt_mask(0x17, 0x80, 0x80);
                break;
        case FB_BLANK_NORMAL:
                pr_debug("fb%d: blank\n", info->node);
                svga_wseq_mask(0x01, 0x20, 0x20);
                svga_wcrt_mask(0x17, 0x80, 0x80);
                break;
        case FB_BLANK_POWERDOWN:
        case FB_BLANK_HSYNC_SUSPEND:
        case FB_BLANK_VSYNC_SUSPEND:
                pr_debug("fb%d: sync down\n", info->node);
                svga_wseq_mask(0x01, 0x20, 0x20);
                svga_wcrt_mask(0x17, 0x00, 0x80);
                break;
        }
        return 0;
}


/* Pan the display */

static int arkfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
        unsigned int offset;

        /* Calculate the offset */
        if (var->bits_per_pixel == 0) {
                offset = (var->yoffset / 16) * (var->xres_virtual / 2) + (var->xoffset / 2);
                offset = offset >> 2;
        } else {
                offset = (var->yoffset * info->fix.line_length) +
                         (var->xoffset * var->bits_per_pixel / 8);
                offset = offset >> ((var->bits_per_pixel == 4) ? 2 : 3);
        }

        /* Set the offset */
        svga_wcrt_multi(ark_start_address_regs, offset);

        return 0;
}


/* ------------------------------------------------------------------------- */


/* Frame buffer operations */

static struct fb_ops arkfb_ops = {
        .owner          = THIS_MODULE,
        .fb_open        = arkfb_open,
        .fb_release     = arkfb_release,
        .fb_check_var   = arkfb_check_var,
        .fb_set_par     = arkfb_set_par,
        .fb_setcolreg   = arkfb_setcolreg,
        .fb_blank       = arkfb_blank,
        .fb_pan_display = arkfb_pan_display,
        .fb_fillrect    = arkfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = arkfb_imageblit,
        .fb_get_caps    = svga_get_caps,
};


/* ------------------------------------------------------------------------- */


/* PCI probe */
static int __devinit ark_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
        struct fb_info *info;
        struct arkfb_info *par;
        int rc;
        u8 regval;

        /* Ignore secondary VGA device because there is no VGA arbitration */
        if (! svga_primary_device(dev)) {
                dev_info(&(dev->dev), "ignoring secondary device\n");
                return -ENODEV;
        }

        /* Allocate and fill driver data structure */
        info = framebuffer_alloc(sizeof(struct arkfb_info), &(dev->dev));
        if (! info) {
                dev_err(&(dev->dev), "cannot allocate memory\n");
                return -ENOMEM;
        }

        par = info->par;
        mutex_init(&par->open_lock);

        info->flags = FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
        info->fbops = &arkfb_ops;

        /* Prepare PCI device */
        rc = pci_enable_device(dev);
        if (rc < 0) {
                dev_err(info->dev, "cannot enable PCI device\n");
                goto err_enable_device;
        }

        rc = pci_request_regions(dev, "arkfb");
        if (rc < 0) {
                dev_err(info->dev, "cannot reserve framebuffer region\n");
                goto err_request_regions;
        }

        par->dac = ics5342_init(ark_dac_read_regs, ark_dac_write_regs, info);
        if (! par->dac) {
                rc = -ENOMEM;
                dev_err(info->dev, "RAMDAC initialization failed\n");
                goto err_dac;
        }

        info->fix.smem_start = pci_resource_start(dev, 0);
        info->fix.smem_len = pci_resource_len(dev, 0);

        /* Map physical IO memory address into kernel space */
        info->screen_base = pci_iomap(dev, 0, 0);
        if (! info->screen_base) {
                rc = -ENOMEM;
                dev_err(info->dev, "iomap for framebuffer failed\n");
                goto err_iomap;
        }

        /* FIXME get memsize */
        regval = vga_rseq(NULL, 0x10);
        info->screen_size = (1 << (regval >> 6)) << 20;
        info->fix.smem_len = info->screen_size;

        strcpy(info->fix.id, "ARK 2000PV");
        info->fix.mmio_start = 0;
        info->fix.mmio_len = 0;
        info->fix.type = FB_TYPE_PACKED_PIXELS;
        info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        info->fix.ypanstep = 0;
        info->fix.accel = FB_ACCEL_NONE;
        info->pseudo_palette = (void*) (par->pseudo_palette);

        /* Prepare startup mode */
        rc = fb_find_mode(&(info->var), info, mode_option, NULL, 0, NULL, 8);
        if (! ((rc == 1) || (rc == 2))) {
                rc = -EINVAL;
                dev_err(info->dev, "mode %s not found\n", mode_option);
                goto err_find_mode;
        }

        rc = fb_alloc_cmap(&info->cmap, 256, 0);
        if (rc < 0) {
                dev_err(info->dev, "cannot allocate colormap\n");
                goto err_alloc_cmap;
        }

        rc = register_framebuffer(info);
        if (rc < 0) {
                dev_err(info->dev, "cannot register framebugger\n");
                goto err_reg_fb;
        }

        printk(KERN_INFO "fb%d: %s on %s, %d MB RAM\n", info->node, info->fix.id,
                 pci_name(dev), info->fix.smem_len >> 20);

        /* Record a reference to the driver data */
        pci_set_drvdata(dev, info);

#ifdef CONFIG_MTRR
        if (mtrr) {
                par->mtrr_reg = -1;
                par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
        }
#endif

        return 0;

        /* Error handling */
err_reg_fb:
        fb_dealloc_cmap(&info->cmap);
err_alloc_cmap:
err_find_mode:
        pci_iounmap(dev, info->screen_base);
err_iomap:
        dac_release(par->dac);
err_dac:
        pci_release_regions(dev);
err_request_regions:
/*      pci_disable_device(dev); */
err_enable_device:
        framebuffer_release(info);
        return rc;
}

/* PCI remove */

static void __devexit ark_pci_remove(struct pci_dev *dev)
{
        struct fb_info *info = pci_get_drvdata(dev);

        if (info) {
                struct arkfb_info *par = info->par;

#ifdef CONFIG_MTRR
                if (par->mtrr_reg >= 0) {
                        mtrr_del(par->mtrr_reg, 0, 0);
                        par->mtrr_reg = -1;
                }
#endif

                dac_release(par->dac);
                unregister_framebuffer(info);
                fb_dealloc_cmap(&info->cmap);

                pci_iounmap(dev, info->screen_base);
                pci_release_regions(dev);
/*              pci_disable_device(dev); */

                pci_set_drvdata(dev, NULL);
                framebuffer_release(info);
        }
}


#ifdef CONFIG_PM
/* PCI suspend */

static int ark_pci_suspend (struct pci_dev* dev, pm_message_t state)
{
        struct fb_info *info = pci_get_drvdata(dev);
        struct arkfb_info *par = info->par;

        dev_info(info->dev, "suspend\n");

        acquire_console_sem();
        mutex_lock(&(par->open_lock));

        if ((state.event == PM_EVENT_FREEZE) || (par->ref_count == 0)) {
                mutex_unlock(&(par->open_lock));
                release_console_sem();
                return 0;
        }

        fb_set_suspend(info, 1);

        pci_save_state(dev);
        pci_disable_device(dev);
        pci_set_power_state(dev, pci_choose_state(dev, state));

        mutex_unlock(&(par->open_lock));
        release_console_sem();

        return 0;
}


/* PCI resume */

static int ark_pci_resume (struct pci_dev* dev)
{
        struct fb_info *info = pci_get_drvdata(dev);
        struct arkfb_info *par = info->par;

        dev_info(info->dev, "resume\n");

        acquire_console_sem();
        mutex_lock(&(par->open_lock));

        if (par->ref_count == 0) {
                mutex_unlock(&(par->open_lock));
                release_console_sem();
                return 0;
        }

        pci_set_power_state(dev, PCI_D0);
        pci_restore_state(dev);

        if (pci_enable_device(dev))
                goto fail;

        pci_set_master(dev);

        arkfb_set_par(info);
        fb_set_suspend(info, 0);

        mutex_unlock(&(par->open_lock));
fail:
        release_console_sem();
        return 0;
}
#else
#define ark_pci_suspend NULL
#define ark_pci_resume NULL
#endif /* CONFIG_PM */

/* List of boards that we are trying to support */

static struct pci_device_id ark_devices[] __devinitdata = {
        {PCI_DEVICE(0xEDD8, 0xA099)},
        {0, 0, 0, 0, 0, 0, 0}
};


MODULE_DEVICE_TABLE(pci, ark_devices);

static struct pci_driver arkfb_pci_driver = {
        .name           = "arkfb",
        .id_table       = ark_devices,
        .probe          = ark_pci_probe,
        .remove         = __devexit_p(ark_pci_remove),
        .suspend        = ark_pci_suspend,
        .resume         = ark_pci_resume,
};

/* Cleanup */

static void __exit arkfb_cleanup(void)
{
        pr_debug("arkfb: cleaning up\n");
        pci_unregister_driver(&arkfb_pci_driver);
}

/* Driver Initialisation */

static int __init arkfb_init(void)
{

#ifndef MODULE
        char *option = NULL;

        if (fb_get_options("arkfb", &option))
                return -ENODEV;

        if (option && *option)
                mode_option = option;
#endif

        pr_debug("arkfb: initializing\n");
        return pci_register_driver(&arkfb_pci_driver);
}

module_init(arkfb_init);
module_exit(arkfb_cleanup);