sysimgblt.c

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/*
 *  Generic 1-bit or 8-bit source to 1-32 bit destination expansion
 *  for frame buffer located in system RAM with packed pixels of any depth.
 *
 *  Based almost entirely on cfbimgblt.c
 *
 *      Copyright (C)  April 2007 Antonino Daplas <[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/module.h>
#include <linux/string.h>
#include <linux/fb.h>
#include <asm/types.h>

#define DEBUG

#ifdef DEBUG
#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt,__func__,## args)
#else
#define DPRINTK(fmt, args...)
#endif

static const u32 cfb_tab8_be[] = {
    0x00000000,0x000000ff,0x0000ff00,0x0000ffff,
    0x00ff0000,0x00ff00ff,0x00ffff00,0x00ffffff,
    0xff000000,0xff0000ff,0xff00ff00,0xff00ffff,
    0xffff0000,0xffff00ff,0xffffff00,0xffffffff
};

static const u32 cfb_tab8_le[] = {
    0x00000000,0xff000000,0x00ff0000,0xffff0000,
    0x0000ff00,0xff00ff00,0x00ffff00,0xffffff00,
    0x000000ff,0xff0000ff,0x00ff00ff,0xffff00ff,
    0x0000ffff,0xff00ffff,0x00ffffff,0xffffffff
};

static const u32 cfb_tab16_be[] = {
    0x00000000, 0x0000ffff, 0xffff0000, 0xffffffff
};

static const u32 cfb_tab16_le[] = {
    0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
};

static const u32 cfb_tab32[] = {
    0x00000000, 0xffffffff
};

static void color_imageblit(const struct fb_image *image, struct fb_info *p,
                void *dst1, u32 start_index, u32 pitch_index)
{
    /* Draw the penguin */
    u32 *dst, *dst2;
    u32 color = 0, val, shift;
    int i, n, bpp = p->var.bits_per_pixel;
    u32 null_bits = 32 - bpp;
    u32 *palette = (u32 *) p->pseudo_palette;
    const u8 *src = image->data;

    dst2 = dst1;
    for (i = image->height; i--; ) {
        n = image->width;
        dst = dst1;
        shift = 0;
        val = 0;

        if (start_index) {
            u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
                             start_index));
            val = *dst & start_mask;
            shift = start_index;
        }
        while (n--) {
            if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
                p->fix.visual == FB_VISUAL_DIRECTCOLOR )
                color = palette[*src];
            else
                color = *src;
            color <<= FB_LEFT_POS(p, bpp);
            val |= FB_SHIFT_HIGH(p, color, shift);
            if (shift >= null_bits) {
                *dst++ = val;

                val = (shift == null_bits) ? 0 :
                    FB_SHIFT_LOW(p, color, 32 - shift);
            }
            shift += bpp;
            shift &= (32 - 1);
            src++;
        }
        if (shift) {
            u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

            *dst &= end_mask;
            *dst |= val;
        }
        dst1 += p->fix.line_length;
        if (pitch_index) {
            dst2 += p->fix.line_length;
            dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));

            start_index += pitch_index;
            start_index &= 32 - 1;
        }
    }
}

static void slow_imageblit(const struct fb_image *image, struct fb_info *p,
                  void *dst1, u32 fgcolor, u32 bgcolor,
                  u32 start_index, u32 pitch_index)
{
    u32 shift, color = 0, bpp = p->var.bits_per_pixel;
    u32 *dst, *dst2;
    u32 val, pitch = p->fix.line_length;
    u32 null_bits = 32 - bpp;
    u32 spitch = (image->width+7)/8;
    const u8 *src = image->data, *s;
    u32 i, j, l;

    dst2 = dst1;
    fgcolor <<= FB_LEFT_POS(p, bpp);
    bgcolor <<= FB_LEFT_POS(p, bpp);

    for (i = image->height; i--; ) {
        shift = val = 0;
        l = 8;
        j = image->width;
        dst = dst1;
        s = src;

        /* write leading bits */
        if (start_index) {
            u32 start_mask = ~(FB_SHIFT_HIGH(p, ~(u32)0,
                             start_index));
            val = *dst & start_mask;
            shift = start_index;
        }

        while (j--) {
            l--;
            color = (*s & (1 << l)) ? fgcolor : bgcolor;
            val |= FB_SHIFT_HIGH(p, color, shift);

            /* Did the bitshift spill bits to the next long? */
            if (shift >= null_bits) {
                *dst++ = val;
                val = (shift == null_bits) ? 0 :
                    FB_SHIFT_LOW(p, color, 32 - shift);
            }
            shift += bpp;
            shift &= (32 - 1);
            if (!l) { l = 8; s++; };
        }

        /* write trailing bits */
        if (shift) {
            u32 end_mask = FB_SHIFT_HIGH(p, ~(u32)0, shift);

            *dst &= end_mask;
            *dst |= val;
        }

        dst1 += pitch;
        src += spitch;
        if (pitch_index) {
            dst2 += pitch;
            dst1 = (u8 *)((long)dst2 & ~(sizeof(u32) - 1));
            start_index += pitch_index;
            start_index &= 32 - 1;
        }

    }
}

/*
 * fast_imageblit - optimized monochrome color expansion
 *
 * Only if:  bits_per_pixel == 8, 16, or 32
 *           image->width is divisible by pixel/dword (ppw);
 *           fix->line_legth is divisible by 4;
 *           beginning and end of a scanline is dword aligned
 */
static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
                  void *dst1, u32 fgcolor, u32 bgcolor)
{
    u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
    u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
    u32 bit_mask, end_mask, eorx, shift;
    const char *s = image->data, *src;
    u32 *dst;
    const u32 *tab = NULL;
    int i, j, k;

    switch (bpp) {
    case 8:
        tab = fb_be_math(p) ? cfb_tab8_be : cfb_tab8_le;
        break;
    case 16:
        tab = fb_be_math(p) ? cfb_tab16_be : cfb_tab16_le;
        break;
    case 32:
    default:
        tab = cfb_tab32;
        break;
    }

    for (i = ppw-1; i--; ) {
        fgx <<= bpp;
        bgx <<= bpp;
        fgx |= fgcolor;
        bgx |= bgcolor;
    }

    bit_mask = (1 << ppw) - 1;
    eorx = fgx ^ bgx;
    k = image->width/ppw;

    for (i = image->height; i--; ) {
        dst = dst1;
        shift = 8;
        src = s;

        for (j = k; j--; ) {
            shift -= ppw;
            end_mask = tab[(*src >> shift) & bit_mask];
            *dst++ = (end_mask & eorx) ^ bgx;
            if (!shift) {
                shift = 8;
                src++;
            }
        }
        dst1 += p->fix.line_length;
        s += spitch;
    }
}

void sys_imageblit(struct fb_info *p, const struct fb_image *image)
{
    u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
    u32 bpl = sizeof(u32), bpp = p->var.bits_per_pixel;
    u32 width = image->width;
    u32 dx = image->dx, dy = image->dy;
    void *dst1;

    if (p->state != FBINFO_STATE_RUNNING)
        return;

    bitstart = (dy * p->fix.line_length * 8) + (dx * bpp);
    start_index = bitstart & (32 - 1);
    pitch_index = (p->fix.line_length & (bpl - 1)) * 8;

    bitstart /= 8;
    bitstart &= ~(bpl - 1);
    dst1 = (void __force *)p->screen_base + bitstart;

    if (p->fbops->fb_sync)
        p->fbops->fb_sync(p);

    if (image->depth == 1) {
        if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
            p->fix.visual == FB_VISUAL_DIRECTCOLOR) {
            fgcolor = ((u32*)(p->pseudo_palette))[image->fg_color];
            bgcolor = ((u32*)(p->pseudo_palette))[image->bg_color];
        } else {
            fgcolor = image->fg_color;
            bgcolor = image->bg_color;
        }

        if (32 % bpp == 0 && !start_index && !pitch_index &&
            ((width & (32/bpp-1)) == 0) &&
            bpp >= 8 && bpp <= 32)
            fast_imageblit(image, p, dst1, fgcolor, bgcolor);
        else
            slow_imageblit(image, p, dst1, fgcolor, bgcolor,
                    start_index, pitch_index);
    } else
        color_imageblit(image, p, dst1, start_index, pitch_index);
}

EXPORT_SYMBOL(sys_imageblit);

MODULE_AUTHOR("Antonino Daplas <[email protected]>");
MODULE_DESCRIPTION("1-bit/8-bit to 1-32 bit color expansion (sys-to-sys)");
MODULE_LICENSE("GPL");