svgalib.c

Go to the documentation of this file.

/*
 * Common utility functions for VGA-based graphics cards.
 *
 * Copyright (c) 2006-2007 Ondrej Zajicek <[email protected]>
 *
 * 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.
 *
 * Some parts are based on David Boucher's viafb (http://davesdomain.org.uk/viafb/)
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fb.h>
#include <linux/svga.h>
#include <asm/types.h>
#include <asm/io.h>


/* Write a CRT register value spread across multiple registers */
void svga_wcrt_multi(void __iomem *regbase, const struct vga_regset *regset, u32 value)
{
    u8 regval, bitval, bitnum;

    while (regset->regnum != VGA_REGSET_END_VAL) {
        regval = vga_rcrt(regbase, regset->regnum);
        bitnum = regset->lowbit;
        while (bitnum <= regset->highbit) {
            bitval = 1 << bitnum;
            regval = regval & ~bitval;
            if (value & 1) regval = regval | bitval;
            bitnum ++;
            value = value >> 1;
        }
        vga_wcrt(regbase, regset->regnum, regval);
        regset ++;
    }
}

/* Write a sequencer register value spread across multiple registers */
void svga_wseq_multi(void __iomem *regbase, const struct vga_regset *regset, u32 value)
{
    u8 regval, bitval, bitnum;

    while (regset->regnum != VGA_REGSET_END_VAL) {
        regval = vga_rseq(regbase, regset->regnum);
        bitnum = regset->lowbit;
        while (bitnum <= regset->highbit) {
            bitval = 1 << bitnum;
            regval = regval & ~bitval;
            if (value & 1) regval = regval | bitval;
            bitnum ++;
            value = value >> 1;
        }
        vga_wseq(regbase, regset->regnum, regval);
        regset ++;
    }
}

static unsigned int svga_regset_size(const struct vga_regset *regset)
{
    u8 count = 0;

    while (regset->regnum != VGA_REGSET_END_VAL) {
        count += regset->highbit - regset->lowbit + 1;
        regset ++;
    }
    return 1 << count;
}


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


/* Set graphics controller registers to sane values */
void svga_set_default_gfx_regs(void __iomem *regbase)
{
    /* All standard GFX registers (GR00 - GR08) */
    vga_wgfx(regbase, VGA_GFX_SR_VALUE, 0x00);
    vga_wgfx(regbase, VGA_GFX_SR_ENABLE, 0x00);
    vga_wgfx(regbase, VGA_GFX_COMPARE_VALUE, 0x00);
    vga_wgfx(regbase, VGA_GFX_DATA_ROTATE, 0x00);
    vga_wgfx(regbase, VGA_GFX_PLANE_READ, 0x00);
    vga_wgfx(regbase, VGA_GFX_MODE, 0x00);
/*  vga_wgfx(regbase, VGA_GFX_MODE, 0x20); */
/*  vga_wgfx(regbase, VGA_GFX_MODE, 0x40); */
    vga_wgfx(regbase, VGA_GFX_MISC, 0x05);
/*  vga_wgfx(regbase, VGA_GFX_MISC, 0x01); */
    vga_wgfx(regbase, VGA_GFX_COMPARE_MASK, 0x0F);
    vga_wgfx(regbase, VGA_GFX_BIT_MASK, 0xFF);
}

/* Set attribute controller registers to sane values */
void svga_set_default_atc_regs(void __iomem *regbase)
{
    u8 count;

    vga_r(regbase, 0x3DA);
    vga_w(regbase, VGA_ATT_W, 0x00);

    /* All standard ATC registers (AR00 - AR14) */
    for (count = 0; count <= 0xF; count ++)
        svga_wattr(regbase, count, count);

    svga_wattr(regbase, VGA_ATC_MODE, 0x01);
/*  svga_wattr(regbase, VGA_ATC_MODE, 0x41); */
    svga_wattr(regbase, VGA_ATC_OVERSCAN, 0x00);
    svga_wattr(regbase, VGA_ATC_PLANE_ENABLE, 0x0F);
    svga_wattr(regbase, VGA_ATC_PEL, 0x00);
    svga_wattr(regbase, VGA_ATC_COLOR_PAGE, 0x00);

    vga_r(regbase, 0x3DA);
    vga_w(regbase, VGA_ATT_W, 0x20);
}

/* Set sequencer registers to sane values */
void svga_set_default_seq_regs(void __iomem *regbase)
{
    /* Standard sequencer registers (SR01 - SR04), SR00 is not set */
    vga_wseq(regbase, VGA_SEQ_CLOCK_MODE, VGA_SR01_CHAR_CLK_8DOTS);
    vga_wseq(regbase, VGA_SEQ_PLANE_WRITE, VGA_SR02_ALL_PLANES);
    vga_wseq(regbase, VGA_SEQ_CHARACTER_MAP, 0x00);
/*  vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM | VGA_SR04_SEQ_MODE | VGA_SR04_CHN_4M); */
    vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM | VGA_SR04_SEQ_MODE);
}

/* Set CRTC registers to sane values */
void svga_set_default_crt_regs(void __iomem *regbase)
{
    /* Standard CRT registers CR03 CR08 CR09 CR14 CR17 */
    svga_wcrt_mask(regbase, 0x03, 0x80, 0x80);  /* Enable vertical retrace EVRA */
    vga_wcrt(regbase, VGA_CRTC_PRESET_ROW, 0);
    svga_wcrt_mask(regbase, VGA_CRTC_MAX_SCAN, 0, 0x1F);
    vga_wcrt(regbase, VGA_CRTC_UNDERLINE, 0);
    vga_wcrt(regbase, VGA_CRTC_MODE, 0xE3);
}

void svga_set_textmode_vga_regs(void __iomem *regbase)
{
    /* svga_wseq_mask(regbase, 0x1, 0x00, 0x01); */   /* Switch 8/9 pixel per char */
    vga_wseq(regbase, VGA_SEQ_MEMORY_MODE, VGA_SR04_EXT_MEM);
    vga_wseq(regbase, VGA_SEQ_PLANE_WRITE, 0x03);

    vga_wcrt(regbase, VGA_CRTC_MAX_SCAN, 0x0f); /* 0x4f */
    vga_wcrt(regbase, VGA_CRTC_UNDERLINE, 0x1f);
    svga_wcrt_mask(regbase, VGA_CRTC_MODE, 0x23, 0x7f);

    vga_wcrt(regbase, VGA_CRTC_CURSOR_START, 0x0d);
    vga_wcrt(regbase, VGA_CRTC_CURSOR_END, 0x0e);
    vga_wcrt(regbase, VGA_CRTC_CURSOR_HI, 0x00);
    vga_wcrt(regbase, VGA_CRTC_CURSOR_LO, 0x00);

    vga_wgfx(regbase, VGA_GFX_MODE, 0x10); /* Odd/even memory mode */
    vga_wgfx(regbase, VGA_GFX_MISC, 0x0E); /* Misc graphics register - text mode enable */
    vga_wgfx(regbase, VGA_GFX_COMPARE_MASK, 0x00);

    vga_r(regbase, 0x3DA);
    vga_w(regbase, VGA_ATT_W, 0x00);

    svga_wattr(regbase, 0x10, 0x0C);            /* Attribute Mode Control Register - text mode, blinking and line graphics */
    svga_wattr(regbase, 0x13, 0x08);            /* Horizontal Pixel Panning Register  */

    vga_r(regbase, 0x3DA);
    vga_w(regbase, VGA_ATT_W, 0x20);
}

#if 0
void svga_dump_var(struct fb_var_screeninfo *var, int node)
{
    pr_debug("fb%d: var.vmode         : 0x%X\n", node, var->vmode);
    pr_debug("fb%d: var.xres          : %d\n", node, var->xres);
    pr_debug("fb%d: var.yres          : %d\n", node, var->yres);
    pr_debug("fb%d: var.bits_per_pixel: %d\n", node, var->bits_per_pixel);
    pr_debug("fb%d: var.xres_virtual  : %d\n", node, var->xres_virtual);
    pr_debug("fb%d: var.yres_virtual  : %d\n", node, var->yres_virtual);
    pr_debug("fb%d: var.left_margin   : %d\n", node, var->left_margin);
    pr_debug("fb%d: var.right_margin  : %d\n", node, var->right_margin);
    pr_debug("fb%d: var.upper_margin  : %d\n", node, var->upper_margin);
    pr_debug("fb%d: var.lower_margin  : %d\n", node, var->lower_margin);
    pr_debug("fb%d: var.hsync_len     : %d\n", node, var->hsync_len);
    pr_debug("fb%d: var.vsync_len     : %d\n", node, var->vsync_len);
    pr_debug("fb%d: var.sync          : 0x%X\n", node, var->sync);
    pr_debug("fb%d: var.pixclock      : %d\n\n", node, var->pixclock);
}
#endif  /*  0  */


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


void svga_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[i * 4] = font[i];
        }
        fb += 128;
        font += map->height;
    }
}

/* Copy area in text (tileblit) mode */
void svga_tilecopy(struct fb_info *info, struct fb_tilearea *area)
{
    int dx, dy;
    /*  colstride is halved in this function because u16 are used */
    int colstride = 1 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
    int rowstride = colstride * (info->var.xres_virtual / 8);
    u16 __iomem *fb = (u16 __iomem *) info->screen_base;
    u16 __iomem *src, *dst;

    if ((area->sy > area->dy) ||
        ((area->sy == area->dy) && (area->sx > area->dx))) {
        src = fb + area->sx * colstride + area->sy * rowstride;
        dst = fb + area->dx * colstride + area->dy * rowstride;
        } else {
        src = fb + (area->sx + area->width - 1) * colstride
             + (area->sy + area->height - 1) * rowstride;
        dst = fb + (area->dx + area->width - 1) * colstride
             + (area->dy + area->height - 1) * rowstride;

        colstride = -colstride;
        rowstride = -rowstride;
        }

    for (dy = 0; dy < area->height; dy++) {
        u16 __iomem *src2 = src;
        u16 __iomem *dst2 = dst;
        for (dx = 0; dx < area->width; dx++) {
            fb_writew(fb_readw(src2), dst2);
//          *dst2 = *src2;
            src2 += colstride;
            dst2 += colstride;
        }
        src += rowstride;
        dst += rowstride;
    }
}

/* Fill area in text (tileblit) mode */
void svga_tilefill(struct fb_info *info, struct fb_tilerect *rect)
{
    int dx, dy;
    int colstride = 2 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
    int rowstride = colstride * (info->var.xres_virtual / 8);
    int attr = (0x0F & rect->bg) << 4 | (0x0F & rect->fg);
    u8 __iomem *fb = (u8 __iomem *)info->screen_base;
    fb += rect->sx * colstride + rect->sy * rowstride;

    for (dy = 0; dy < rect->height; dy++) {
        u8 __iomem *fb2 = fb;
        for (dx = 0; dx < rect->width; dx++) {
            fb_writeb(rect->index, fb2);
            fb_writeb(attr, fb2 + 1);
            fb2 += colstride;
        }
        fb += rowstride;
    }
}

/* Write text in text (tileblit) mode */
void svga_tileblit(struct fb_info *info, struct fb_tileblit *blit)
{
    int dx, dy, i;
    int colstride = 2 << (info->fix.type_aux & FB_AUX_TEXT_SVGA_MASK);
    int rowstride = colstride * (info->var.xres_virtual / 8);
    int attr = (0x0F & blit->bg) << 4 | (0x0F & blit->fg);
    u8 __iomem *fb = (u8 __iomem *)info->screen_base;
    fb += blit->sx * colstride + blit->sy * rowstride;

    i=0;
    for (dy=0; dy < blit->height; dy ++) {
        u8 __iomem *fb2 = fb;
        for (dx = 0; dx < blit->width; dx ++) {
            fb_writeb(blit->indices[i], fb2);
            fb_writeb(attr, fb2 + 1);
            fb2 += colstride;
            i ++;
            if (i == blit->length) return;
        }
        fb += rowstride;
    }

}

/* Set cursor in text (tileblit) mode */
void svga_tilecursor(void __iomem *regbase, struct fb_info *info, struct fb_tilecursor *cursor)
{
    u8 cs = 0x0d;
    u8 ce = 0x0e;
    u16 pos =  cursor->sx + (info->var.xoffset /  8)
        + (cursor->sy + (info->var.yoffset / 16))
           * (info->var.xres_virtual / 8);

    if (! cursor -> mode)
        return;

    svga_wcrt_mask(regbase, 0x0A, 0x20, 0x20); /* disable cursor */

    if (cursor -> shape == FB_TILE_CURSOR_NONE)
        return;

    switch (cursor -> shape) {
    case FB_TILE_CURSOR_UNDERLINE:
        cs = 0x0d;
        break;
    case FB_TILE_CURSOR_LOWER_THIRD:
        cs = 0x09;
        break;
    case FB_TILE_CURSOR_LOWER_HALF:
        cs = 0x07;
        break;
    case FB_TILE_CURSOR_TWO_THIRDS:
        cs = 0x05;
        break;
    case FB_TILE_CURSOR_BLOCK:
        cs = 0x01;
        break;
    }

    /* set cursor position */
    vga_wcrt(regbase, 0x0E, pos >> 8);
    vga_wcrt(regbase, 0x0F, pos & 0xFF);

    vga_wcrt(regbase, 0x0B, ce); /* set cursor end */
    vga_wcrt(regbase, 0x0A, cs); /* set cursor start and enable it */
}

int svga_get_tilemax(struct fb_info *info)
{
    return 256;
}

/* Get capabilities of accelerator based on the mode */

void svga_get_caps(struct fb_info *info, struct fb_blit_caps *caps,
           struct fb_var_screeninfo *var)
{
    if (var->bits_per_pixel == 0) {
        /* can only support 256 8x16 bitmap */
        caps->x = 1 << (8 - 1);
        caps->y = 1 << (16 - 1);
        caps->len = 256;
    } else {
        caps->x = (var->bits_per_pixel == 4) ? 1 << (8 - 1) : ~(u32)0;
        caps->y = ~(u32)0;
        caps->len = ~(u32)0;
    }
}
EXPORT_SYMBOL(svga_get_caps);

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


/*
 *  Compute PLL settings (M, N, R)
 *  F_VCO = (F_BASE * M) / N
 *  F_OUT = F_VCO / (2^R)
 */

static inline u32 abs_diff(u32 a, u32 b)
{
    return (a > b) ? (a - b) : (b - a);
}

int svga_compute_pll(const struct svga_pll *pll, u32 f_wanted, u16 *m, u16 *n, u16 *r, int node)
{
    u16 am, an, ar;
    u32 f_vco, f_current, delta_current, delta_best;

    pr_debug("fb%d: ideal frequency: %d kHz\n", node, (unsigned int) f_wanted);

    ar = pll->r_max;
    f_vco = f_wanted << ar;

    /* overflow check */
    if ((f_vco >> ar) != f_wanted)
        return -EINVAL;

    /* It is usually better to have greater VCO clock
       because of better frequency stability.
       So first try r_max, then r smaller. */
    while ((ar > pll->r_min) && (f_vco > pll->f_vco_max)) {
        ar--;
        f_vco = f_vco >> 1;
    }

    /* VCO bounds check */
    if ((f_vco < pll->f_vco_min) || (f_vco > pll->f_vco_max))
        return -EINVAL;

    delta_best = 0xFFFFFFFF;
    *m = 0;
    *n = 0;
    *r = ar;

    am = pll->m_min;
    an = pll->n_min;

    while ((am <= pll->m_max) && (an <= pll->n_max)) {
        f_current = (pll->f_base * am) / an;
        delta_current = abs_diff (f_current, f_vco);

        if (delta_current < delta_best) {
            delta_best = delta_current;
            *m = am;
            *n = an;
        }

        if (f_current <= f_vco) {
            am ++;
        } else {
            an ++;
        }
    }

    f_current = (pll->f_base * *m) / *n;
    pr_debug("fb%d: found frequency: %d kHz (VCO %d kHz)\n", node, (int) (f_current >> ar), (int) f_current);
    pr_debug("fb%d: m = %d n = %d r = %d\n", node, (unsigned int) *m, (unsigned int) *n, (unsigned int) *r);
    return 0;
}


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


/* Check CRT timing values */
int svga_check_timings(const struct svga_timing_regs *tm, struct fb_var_screeninfo *var, int node)
{
    u32 value;

    var->xres         = (var->xres+7)&~7;
    var->left_margin  = (var->left_margin+7)&~7;
    var->right_margin = (var->right_margin+7)&~7;
    var->hsync_len    = (var->hsync_len+7)&~7;

    /* Check horizontal total */
    value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
    if (((value / 8) - 5) >= svga_regset_size (tm->h_total_regs))
        return -EINVAL;

    /* Check horizontal display and blank start */
    value = var->xres;
    if (((value / 8) - 1) >= svga_regset_size (tm->h_display_regs))
        return -EINVAL;
    if (((value / 8) - 1) >= svga_regset_size (tm->h_blank_start_regs))
        return -EINVAL;

    /* Check horizontal sync start */
    value = var->xres + var->right_margin;
    if (((value / 8) - 1) >= svga_regset_size (tm->h_sync_start_regs))
        return -EINVAL;

    /* Check horizontal blank end (or length) */
    value = var->left_margin + var->right_margin + var->hsync_len;
    if ((value == 0) || ((value / 8) >= svga_regset_size (tm->h_blank_end_regs)))
        return -EINVAL;

    /* Check horizontal sync end (or length) */
    value = var->hsync_len;
    if ((value == 0) || ((value / 8) >= svga_regset_size (tm->h_sync_end_regs)))
        return -EINVAL;

    /* Check vertical total */
    value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
    if ((value - 1) >= svga_regset_size(tm->v_total_regs))
        return -EINVAL;

    /* Check vertical display and blank start */
    value = var->yres;
    if ((value - 1) >= svga_regset_size(tm->v_display_regs))
        return -EINVAL;
    if ((value - 1) >= svga_regset_size(tm->v_blank_start_regs))
        return -EINVAL;

    /* Check vertical sync start */
    value = var->yres + var->lower_margin;
    if ((value - 1) >= svga_regset_size(tm->v_sync_start_regs))
        return -EINVAL;

    /* Check vertical blank end (or length) */
    value = var->upper_margin + var->lower_margin + var->vsync_len;
    if ((value == 0) || (value >= svga_regset_size (tm->v_blank_end_regs)))
        return -EINVAL;

    /* Check vertical sync end  (or length) */
    value = var->vsync_len;
    if ((value == 0) || (value >= svga_regset_size (tm->v_sync_end_regs)))
        return -EINVAL;

    return 0;
}

/* Set CRT timing registers */
void svga_set_timings(void __iomem *regbase, const struct svga_timing_regs *tm,
              struct fb_var_screeninfo *var,
              u32 hmul, u32 hdiv, u32 vmul, u32 vdiv, u32 hborder, int node)
{
    u8 regval;
    u32 value;

    value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal total      : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_total_regs, (value / 8) - 5);

    value = var->xres;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal display    : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_display_regs, (value / 8) - 1);

    value = var->xres;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal blank start: %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_blank_start_regs, (value / 8) - 1 + hborder);

    value = var->xres + var->left_margin + var->right_margin + var->hsync_len;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal blank end  : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_blank_end_regs, (value / 8) - 1 - hborder);

    value = var->xres + var->right_margin;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal sync start : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_sync_start_regs, (value / 8));

    value = var->xres + var->right_margin + var->hsync_len;
    value = (value * hmul) / hdiv;
    pr_debug("fb%d: horizontal sync end   : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->h_sync_end_regs, (value / 8));

    value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical total        : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_total_regs, value - 2);

    value = var->yres;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical display      : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_display_regs, value - 1);

    value = var->yres;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical blank start  : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_blank_start_regs, value);

    value = var->yres + var->upper_margin + var->lower_margin + var->vsync_len;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical blank end    : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_blank_end_regs, value - 2);

    value = var->yres + var->lower_margin;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical sync start   : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_sync_start_regs, value);

    value = var->yres + var->lower_margin + var->vsync_len;
    value = (value * vmul) / vdiv;
    pr_debug("fb%d: vertical sync end     : %d\n", node, value);
    svga_wcrt_multi(regbase, tm->v_sync_end_regs, value);

    /* Set horizontal and vertical sync pulse polarity in misc register */

    regval = vga_r(regbase, VGA_MIS_R);
    if (var->sync & FB_SYNC_HOR_HIGH_ACT) {
        pr_debug("fb%d: positive horizontal sync\n", node);
        regval = regval & ~0x80;
    } else {
        pr_debug("fb%d: negative horizontal sync\n", node);
        regval = regval | 0x80;
    }
    if (var->sync & FB_SYNC_VERT_HIGH_ACT) {
        pr_debug("fb%d: positive vertical sync\n", node);
        regval = regval & ~0x40;
    } else {
        pr_debug("fb%d: negative vertical sync\n\n", node);
        regval = regval | 0x40;
    }
    vga_w(regbase, VGA_MIS_W, regval);
}


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


static inline int match_format(const struct svga_fb_format *frm,
                   struct fb_var_screeninfo *var)
{
    int i = 0;
    int stored = -EINVAL;

    while (frm->bits_per_pixel != SVGA_FORMAT_END_VAL)
    {
        if ((var->bits_per_pixel == frm->bits_per_pixel) &&
            (var->red.length     <= frm->red.length)     &&
            (var->green.length   <= frm->green.length)   &&
            (var->blue.length    <= frm->blue.length)    &&
            (var->transp.length  <= frm->transp.length)  &&
            (var->nonstd     == frm->nonstd))
            return i;
        if (var->bits_per_pixel == frm->bits_per_pixel)
            stored = i;
        i++;
        frm++;
    }
    return stored;
}

int svga_match_format(const struct svga_fb_format *frm,
              struct fb_var_screeninfo *var,
              struct fb_fix_screeninfo *fix)
{
    int i = match_format(frm, var);

    if (i >= 0) {
        var->bits_per_pixel = frm[i].bits_per_pixel;
        var->red            = frm[i].red;
        var->green          = frm[i].green;
        var->blue           = frm[i].blue;
        var->transp         = frm[i].transp;
        var->nonstd         = frm[i].nonstd;
        if (fix != NULL) {
            fix->type      = frm[i].type;
            fix->type_aux  = frm[i].type_aux;
            fix->visual    = frm[i].visual;
            fix->xpanstep  = frm[i].xpanstep;
        }
    }

    return i;
}


EXPORT_SYMBOL(svga_wcrt_multi);
EXPORT_SYMBOL(svga_wseq_multi);

EXPORT_SYMBOL(svga_set_default_gfx_regs);
EXPORT_SYMBOL(svga_set_default_atc_regs);
EXPORT_SYMBOL(svga_set_default_seq_regs);
EXPORT_SYMBOL(svga_set_default_crt_regs);
EXPORT_SYMBOL(svga_set_textmode_vga_regs);

EXPORT_SYMBOL(svga_settile);
EXPORT_SYMBOL(svga_tilecopy);
EXPORT_SYMBOL(svga_tilefill);
EXPORT_SYMBOL(svga_tileblit);
EXPORT_SYMBOL(svga_tilecursor);
EXPORT_SYMBOL(svga_get_tilemax);

EXPORT_SYMBOL(svga_compute_pll);
EXPORT_SYMBOL(svga_check_timings);
EXPORT_SYMBOL(svga_set_timings);
EXPORT_SYMBOL(svga_match_format);

MODULE_AUTHOR("Ondrej Zajicek <[email protected]>");
MODULE_DESCRIPTION("Common utility functions for VGA-based graphics cards");
MODULE_LICENSE("GPL");