/*
 *  linux/drivers/video/fbcmap.c -- Colormap handling for frame buffer devices
 *
 *      Created 15 Jun 1997 by Geert Uytterhoeven
 *
 *      2001 - Documented with DocBook
 *      - Brad Douglas <brad@neruo.com>
 *
 *  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.
 */

#include <linux/string.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/fb.h>
#include <linux/slab.h>

#include <asm/uaccess.h>

static u16 red2[] = {
    0x0000, 0xaaaa
};
static u16 green2[] = {
    0x0000, 0xaaaa
};
static u16 blue2[] = {
    0x0000, 0xaaaa
};

static u16 red4[] = {
    0x0000, 0xaaaa, 0x5555, 0xffff
};
static u16 green4[] = {
    0x0000, 0xaaaa, 0x5555, 0xffff
};
static u16 blue4[] = {
    0x0000, 0xaaaa, 0x5555, 0xffff
};

static u16 red8[] = {
    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa
};
static u16 green8[] = {
    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa
};
static u16 blue8[] = {
    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa
};

static u16 red16[] = {
    0x0000, 0x0000, 0x0000, 0x0000, 0xaaaa, 0xaaaa, 0xaaaa, 0xaaaa,
    0x5555, 0x5555, 0x5555, 0x5555, 0xffff, 0xffff, 0xffff, 0xffff
};
static u16 green16[] = {
    0x0000, 0x0000, 0xaaaa, 0xaaaa, 0x0000, 0x0000, 0x5555, 0xaaaa,
    0x5555, 0x5555, 0xffff, 0xffff, 0x5555, 0x5555, 0xffff, 0xffff
};
static u16 blue16[] = {
    0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa, 0x0000, 0xaaaa,
    0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff, 0x5555, 0xffff
};

static struct fb_cmap default_2_colors = {
    0, 2, red2, green2, blue2, NULL
};
static struct fb_cmap default_8_colors = {
    0, 8, red8, green8, blue8, NULL
};
static struct fb_cmap default_4_colors = {
    0, 4, red4, green4, blue4, NULL
};
static struct fb_cmap default_16_colors = {
    0, 16, red16, green16, blue16, NULL
};


/**
 *      fb_alloc_cmap - allocate a colormap
 *      @cmap: frame buffer colormap structure
 *      @len: length of @cmap
 *      @transp: boolean, 1 if there is transparency, 0 otherwise
 *
 *      Allocates memory for a colormap @cmap.  @len is the
 *      number of entries in the palette.
 *
 *      Returns -1 errno on error, or zero on success.
 *
 */

int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
{
    int size = len*sizeof(u16);

    if (cmap->len != len) {
        if (cmap->red)
            kfree(cmap->red);
        if (cmap->green)
            kfree(cmap->green);
        if (cmap->blue)
            kfree(cmap->blue);
        if (cmap->transp)
            kfree(cmap->transp);
        cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
        cmap->len = 0;
        if (!len)
            return 0;
        if (!(cmap->red = kmalloc(size, GFP_ATOMIC)))
            return -1;
        if (!(cmap->green = kmalloc(size, GFP_ATOMIC)))
            return -1;
        if (!(cmap->blue = kmalloc(size, GFP_ATOMIC)))
            return -1;
        if (transp) {
            if (!(cmap->transp = kmalloc(size, GFP_ATOMIC)))
                return -1;
        } else
            cmap->transp = NULL;
    }
    cmap->start = 0;
    cmap->len = len;
    fb_copy_cmap(fb_default_cmap(len), cmap, 0);
    return 0;
}


/**
 *      fb_copy_cmap - copy a colormap
 *      @from: frame buffer colormap structure
 *      @to: frame buffer colormap structure
 *      @fsfromto: determine copy method
 *
 *      Copy contents of colormap from @from to @to.
 *
 *      @fsfromto accepts the following integer parameters:
 *      0: memcpy function
 *      1: copy_from_user() function to copy from userspace
 *      2: copy_to_user() function to copy to userspace
 *
 */

void fb_copy_cmap(struct fb_cmap *from, struct fb_cmap *to, int fsfromto)
{
    int size;
    int tooff = 0, fromoff = 0;

    if (to->start > from->start)
        fromoff = to->start-from->start;
    else
        tooff = from->start-to->start;
    size = to->len-tooff;
    if (size > from->len-fromoff)
        size = from->len-fromoff;
    if (size < 0)
        return;
    size *= sizeof(u16);
    
    switch (fsfromto) {
    case 0:
        memcpy(to->red+tooff, from->red+fromoff, size);
        memcpy(to->green+tooff, from->green+fromoff, size);
        memcpy(to->blue+tooff, from->blue+fromoff, size);
        if (from->transp && to->transp)
            memcpy(to->transp+tooff, from->transp+fromoff, size);
        break;
    case 1:
        copy_from_user(to->red+tooff, from->red+fromoff, size);
        copy_from_user(to->green+tooff, from->green+fromoff, size);
        copy_from_user(to->blue+tooff, from->blue+fromoff, size);
        if (from->transp && to->transp)
            copy_from_user(to->transp+tooff, from->transp+fromoff, size);
        break;
    case 2:
        copy_to_user(to->red+tooff, from->red+fromoff, size);
        copy_to_user(to->green+tooff, from->green+fromoff, size);
        copy_to_user(to->blue+tooff, from->blue+fromoff, size);
        if (from->transp && to->transp)
            copy_to_user(to->transp+tooff, from->transp+fromoff, size);
        break;
    }
}


/**
 *      fb_get_cmap - get a colormap
 *      @cmap: frame buffer colormap
 *      @kspc: boolean, 0 copy local, 1 put_user() function
 *      @getcolreg: pointer to a function to get a color register
 *      @info: frame buffer info structure
 *
 *      Get a colormap @cmap for a screen of device @info.
 *
 *      Returns negative errno on error, or zero on success.
 *
 */

int fb_get_cmap(struct fb_cmap *cmap, int kspc,
                int (*getcolreg)(u_int, u_int *, u_int *, u_int *, u_int *,
                                 struct fb_info *),
                struct fb_info *info)
{
    int i, start;
    u16 *red, *green, *blue, *transp;
    u_int hred, hgreen, hblue, htransp;

    red = cmap->red;
    green = cmap->green;
    blue = cmap->blue;
    transp = cmap->transp;
    start = cmap->start;
    if (start < 0)
        return -EINVAL;
    for (i = 0; i < cmap->len; i++) {
        if (getcolreg(start++, &hred, &hgreen, &hblue, &htransp, info))
            return 0;
        if (kspc) {
            *red = hred;
            *green = hgreen;
            *blue = hblue;
            if (transp)
                *transp = htransp;
        } else {
            put_user(hred, red);
            put_user(hgreen, green);
            put_user(hblue, blue);
            if (transp)
                put_user(htransp, transp);
        }
        red++;
        green++;
        blue++;
        if (transp)
            transp++;
    }
    return 0;
}


/**
 *      fb_set_cmap - set the colormap
 *      @cmap: frame buffer colormap structure
 *      @kspc: boolean, 0 copy local, 1 get_user() function
 *      @info: frame buffer info structure
 *
 *      Sets the colormap @cmap for a screen of device @info.
 *
 *      Returns negative errno on error, or zero on success.
 *
 */

int fb_set_cmap(struct fb_cmap *cmap, int kspc,
                int (*setcolreg)(u_int, u_int, u_int, u_int, u_int,
                                 struct fb_info *),
                struct fb_info *info)
{
    int i, start;
    u16 *red, *green, *blue, *transp;
    u_int hred, hgreen, hblue, htransp;

    red = cmap->red;
    green = cmap->green;
    blue = cmap->blue;
    transp = cmap->transp;
    start = cmap->start;

    if (start < 0)
        return -EINVAL;
    for (i = 0; i < cmap->len; i++) {
        if (kspc) {
            hred = *red;
            hgreen = *green;
            hblue = *blue;
            htransp = transp ? *transp : 0xffff;
        } else {
            get_user(hred, red);
            get_user(hgreen, green);
            get_user(hblue, blue);
            if (transp)
                get_user(htransp, transp);
            else
                htransp = 0xffff;
        }
        red++;
        green++;
        blue++;
        if (transp)
            transp++;
        if (setcolreg(start++, hred, hgreen, hblue, htransp, info))
            return 0;
    }
    return 0;
}


/**
 *      fb_default_cmap - get default colormap
 *      @len: size of palette for a depth
 *
 *      Gets the default colormap for a specific screen depth.  @len
 *      is the size of the palette for a particular screen depth.
 *
 *      Returns pointer to a frame buffer colormap structure.
 *
 */

struct fb_cmap *fb_default_cmap(int len)
{
    if (len <= 2)
        return &default_2_colors;
    if (len <= 4)
        return &default_4_colors;
    if (len <= 8)
        return &default_8_colors;
    return &default_16_colors;
}


/**
 *      fb_invert_cmaps - invert all defaults colormaps
 *
 *      Invert all default colormaps.
 *
 */

void fb_invert_cmaps(void)
{
    u_int i;

    for (i = 0; i < 2; i++) {
        red2[i] = ~red2[i];
        green2[i] = ~green2[i];
        blue2[i] = ~blue2[i];
    }
    for (i = 0; i < 4; i++) {
        red4[i] = ~red4[i];
        green4[i] = ~green4[i];
        blue4[i] = ~blue4[i];
    }
    for (i = 0; i < 8; i++) {
        red8[i] = ~red8[i];
        green8[i] = ~green8[i];
        blue8[i] = ~blue8[i];
    }
    for (i = 0; i < 16; i++) {
        red16[i] = ~red16[i];
        green16[i] = ~green16[i];
        blue16[i] = ~blue16[i];
    }
}


    /*
     *  Visible symbols for modules
     */

EXPORT_SYMBOL(fb_alloc_cmap);
EXPORT_SYMBOL(fb_copy_cmap);
EXPORT_SYMBOL(fb_get_cmap);
EXPORT_SYMBOL(fb_set_cmap);
EXPORT_SYMBOL(fb_default_cmap);
EXPORT_SYMBOL(fb_invert_cmaps);