fbcmap.c

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

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

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

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

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

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

static const struct fb_cmap default_2_colors = {
    .len=2, .red=red2, .green=green2, .blue=blue2
};
static const struct fb_cmap default_8_colors = {
    .len=8, .red=red8, .green=green8, .blue=blue8
};
static const struct fb_cmap default_4_colors = {
    .len=4, .red=red4, .green=green4, .blue=blue4
};
static const struct fb_cmap default_16_colors = {
    .len=16, .red=red16, .green=green16, .blue=blue16
};



int fb_alloc_cmap_gfp(struct fb_cmap *cmap, int len, int transp, gfp_t flags)
{
    int size = len * sizeof(u16);
    int ret = -ENOMEM;

    if (cmap->len != len) {
        fb_dealloc_cmap(cmap);
        if (!len)
            return 0;

        cmap->red = kmalloc(size, flags);
        if (!cmap->red)
            goto fail;
        cmap->green = kmalloc(size, flags);
        if (!cmap->green)
            goto fail;
        cmap->blue = kmalloc(size, flags);
        if (!cmap->blue)
            goto fail;
        if (transp) {
            cmap->transp = kmalloc(size, flags);
            if (!cmap->transp)
                goto fail;
        } else {
            cmap->transp = NULL;
        }
    }
    cmap->start = 0;
    cmap->len = len;
    ret = fb_copy_cmap(fb_default_cmap(len), cmap);
    if (ret)
        goto fail;
    return 0;

fail:
    fb_dealloc_cmap(cmap);
    return ret;
}

int fb_alloc_cmap(struct fb_cmap *cmap, int len, int transp)
{
    return fb_alloc_cmap_gfp(cmap, len, transp, GFP_ATOMIC);
}

void fb_dealloc_cmap(struct fb_cmap *cmap)
{
    kfree(cmap->red);
    kfree(cmap->green);
    kfree(cmap->blue);
    kfree(cmap->transp);

    cmap->red = cmap->green = cmap->blue = cmap->transp = NULL;
    cmap->len = 0;
}

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

    if (to->start > from->start)
        fromoff = to->start - from->start;
    else
        tooff = from->start - to->start;
    size = to->len - tooff;
    if (size > (int) (from->len - fromoff))
        size = from->len - fromoff;
    if (size <= 0)
        return -EINVAL;
    size *= sizeof(u16);

    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);
    return 0;
}

int fb_cmap_to_user(const struct fb_cmap *from, struct fb_cmap_user *to)
{
    int tooff = 0, fromoff = 0;
    int size;

    if (to->start > from->start)
        fromoff = to->start - from->start;
    else
        tooff = from->start - to->start;
    size = to->len - tooff;
    if (size > (int) (from->len - fromoff))
        size = from->len - fromoff;
    if (size <= 0)
        return -EINVAL;
    size *= sizeof(u16);

    if (copy_to_user(to->red+tooff, from->red+fromoff, size))
        return -EFAULT;
    if (copy_to_user(to->green+tooff, from->green+fromoff, size))
        return -EFAULT;
    if (copy_to_user(to->blue+tooff, from->blue+fromoff, size))
        return -EFAULT;
    if (from->transp && to->transp)
        if (copy_to_user(to->transp+tooff, from->transp+fromoff, size))
            return -EFAULT;
    return 0;
}

int fb_set_cmap(struct fb_cmap *cmap, struct fb_info *info)
{
    int i, start, rc = 0;
    u16 *red, *green, *blue, *transp;
    u_int hred, hgreen, hblue, htransp = 0xffff;

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

    if (start < 0 || (!info->fbops->fb_setcolreg &&
              !info->fbops->fb_setcmap))
        return -EINVAL;
    if (info->fbops->fb_setcmap) {
        rc = info->fbops->fb_setcmap(cmap, info);
    } else {
        for (i = 0; i < cmap->len; i++) {
            hred = *red++;
            hgreen = *green++;
            hblue = *blue++;
            if (transp)
                htransp = *transp++;
            if (info->fbops->fb_setcolreg(start++,
                              hred, hgreen, hblue,
                              htransp, info))
                break;
        }
    }
    if (rc == 0)
        fb_copy_cmap(cmap, &info->cmap);

    return rc;
}

int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info)
{
    int rc, size = cmap->len * sizeof(u16);
    struct fb_cmap umap;

    if (size < 0 || size < cmap->len)
        return -E2BIG;

    memset(&umap, 0, sizeof(struct fb_cmap));
    rc = fb_alloc_cmap_gfp(&umap, cmap->len, cmap->transp != NULL,
                GFP_KERNEL);
    if (rc)
        return rc;
    if (copy_from_user(umap.red, cmap->red, size) ||
        copy_from_user(umap.green, cmap->green, size) ||
        copy_from_user(umap.blue, cmap->blue, size) ||
        (cmap->transp && copy_from_user(umap.transp, cmap->transp, size))) {
        rc = -EFAULT;
        goto out;
    }
    umap.start = cmap->start;
    if (!lock_fb_info(info)) {
        rc = -ENODEV;
        goto out;
    }
    if (cmap->start < 0 || (!info->fbops->fb_setcolreg &&
                !info->fbops->fb_setcmap)) {
        rc = -EINVAL;
        goto out1;
    }
    rc = fb_set_cmap(&umap, info);
out1:
    unlock_fb_info(info);
out:
    fb_dealloc_cmap(&umap);
    return rc;
}

const 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;
}


void fb_invert_cmaps(void)
{
    u_int i;

    for (i = 0; i < ARRAY_SIZE(red2); i++) {
    red2[i] = ~red2[i];
    green2[i] = ~green2[i];
    blue2[i] = ~blue2[i];
    }
    for (i = 0; i < ARRAY_SIZE(red4); i++) {
    red4[i] = ~red4[i];
    green4[i] = ~green4[i];
    blue4[i] = ~blue4[i];
    }
    for (i = 0; i < ARRAY_SIZE(red8); i++) {
    red8[i] = ~red8[i];
    green8[i] = ~green8[i];
    blue8[i] = ~blue8[i];
    }
    for (i = 0; i < ARRAY_SIZE(red16); 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_dealloc_cmap);
EXPORT_SYMBOL(fb_copy_cmap);
EXPORT_SYMBOL(fb_set_cmap);
EXPORT_SYMBOL(fb_default_cmap);
EXPORT_SYMBOL(fb_invert_cmaps);