/*
 *  linux/drivers/video/ilbm.c -- Low level frame buffer operations for
 *                                interleaved bitplanes à la Amiga
 *
 *      Created 5 Apr 1997 by Geert Uytterhoeven
 *
 *  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/tty.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/fb.h>

#include <video/fbcon.h>
#include <video/fbcon-ilbm.h>


    /*
     *  Interleaved bitplanes à la Amiga
     *
     *  This code heavily relies on the fact that
     *
     *      next_line == interleave == next_plane*bits_per_pixel
     *
     *  But maybe it can be merged with the code for normal bitplanes without
     *  much performance loss?
     */

void fbcon_ilbm_setup(struct display *p)
{
    if (p->line_length) {
        p->next_line = p->line_length*p->var.bits_per_pixel;
        p->next_plane = p->line_length;
    } else {
        p->next_line = p->type_aux;
        p->next_plane = p->type_aux/p->var.bits_per_pixel;
    }
}

void fbcon_ilbm_bmove(struct display *p, int sy, int sx, int dy, int dx,
                      int height, int width)
{
    if (sx == 0 && dx == 0 && width == p->next_plane)
        fb_memmove(p->screen_base+dy*fontheight(p)*p->next_line,
                  p->screen_base+sy*fontheight(p)*p->next_line,
                  height*fontheight(p)*p->next_line);
    else {
        u8 *src, *dest;
        u_int i;

        if (dy <= sy) {
            src = p->screen_base+sy*fontheight(p)*p->next_line+sx;
            dest = p->screen_base+dy*fontheight(p)*p->next_line+dx;
            for (i = p->var.bits_per_pixel*height*fontheight(p); i--;) {
                fb_memmove(dest, src, width);
                src += p->next_plane;
                dest += p->next_plane;
            }
        } else {
            src = p->screen_base+(sy+height)*fontheight(p)*p->next_line+sx;
            dest = p->screen_base+(dy+height)*fontheight(p)*p->next_line+dx;
            for (i = p->var.bits_per_pixel*height*fontheight(p); i--;) {
                src -= p->next_plane;
                dest -= p->next_plane;
                fb_memmove(dest, src, width);
            }
        }
    }
}

void fbcon_ilbm_clear(struct vc_data *conp, struct display *p, int sy, int sx,
                      int height, int width)
{
    u8 *dest;
    u_int i, rows;
    int bg, bg0;

    dest = p->screen_base+sy*fontheight(p)*p->next_line+sx;

    bg0 = attr_bgcol_ec(p,conp);
    for (rows = height*fontheight(p); rows--;) {
        bg = bg0;
        for (i = p->var.bits_per_pixel; i--; dest += p->next_plane) {
            if (bg & 1)
                fb_memset255(dest, width);
            else
                fb_memclear(dest, width);
            bg >>= 1;
        }
    }
}

void fbcon_ilbm_putc(struct vc_data *conp, struct display *p, int c, int yy,
                     int xx)
{
    u8 *dest, *cdat;
    u_int rows, i;
    u8 d;
    int fg0, bg0, fg, bg;

    dest = p->screen_base+yy*fontheight(p)*p->next_line+xx;
    cdat = p->fontdata+(c&p->charmask)*fontheight(p);
    fg0 = attr_fgcol(p,c);
    bg0 = attr_bgcol(p,c);

    for (rows = fontheight(p); rows--;) {
        d = *cdat++;
        fg = fg0;
        bg = bg0;
        for (i = p->var.bits_per_pixel; i--; dest += p->next_plane) {
            if (bg & 1){
                if (fg & 1)
                    *dest = 0xff;
                else
                    *dest = ~d;
            }else{
                if (fg & 1)
                    *dest = d;
                else
                    *dest = 0x00;
            }
            bg >>= 1;
            fg >>= 1;
        }
    }
}

    /*
     *  I've split the console character loop in two parts:
     *
     *      - slow version: this blits one character at a time
     *
     *      - fast version: this blits 4 characters at a time at a longword
     *                      aligned address, to reduce the number of expensive
     *                      Chip RAM accesses.
     *
     *  Experiments on my A4000/040 revealed that this makes a console switch
     *  on a 640x400 screen with 256 colors about 3 times faster.
     *
     *  -- Geert
     */

void fbcon_ilbm_putcs(struct vc_data *conp, struct display *p, 
                      const unsigned short *s, int count, int yy, int xx)
{
    u8 *dest0, *dest, *cdat1, *cdat2, *cdat3, *cdat4;
    u_int rows, i;
    u16 c1, c2, c3, c4;
    u32 d;
    int fg0, bg0, fg, bg;

    dest0 = p->screen_base+yy*fontheight(p)*p->next_line+xx;
    c1 = scr_readw(s);
    fg0 = attr_fgcol(p, c1);
    bg0 = attr_bgcol(p, c1);

    while (count--)
        if (xx&3 || count < 3) {        /* Slow version */
            c1 = scr_readw(s++) & p->charmask;
            dest = dest0++;
            xx++;

            cdat1 = p->fontdata+c1*fontheight(p);
            for (rows = fontheight(p); rows--;) {
                d = *cdat1++;
                fg = fg0;
                bg = bg0;
                for (i = p->var.bits_per_pixel; i--; dest += p->next_plane) {
                    if (bg & 1){
                        if (fg & 1)
                            *dest = 0xff;
                        else
                            *dest = ~d;
                    }else{
                        if (fg & 1)
                            *dest = d;
                        else
                            *dest = 0x00;
                    }
                    bg >>= 1;
                    fg >>= 1;
                }
            }
        } else {                /* Fast version */
            c1 = scr_readw(&s[0]) & p->charmask;
            c2 = scr_readw(&s[1]) & p->charmask;
            c3 = scr_readw(&s[2]) & p->charmask;
            c4 = scr_readw(&s[3]) & p->charmask;

            dest = dest0;
            cdat1 = p->fontdata+c1*fontheight(p);
            cdat2 = p->fontdata+c2*fontheight(p);
            cdat3 = p->fontdata+c3*fontheight(p);
            cdat4 = p->fontdata+c4*fontheight(p);
            for (rows = fontheight(p); rows--;) {
#if defined(__BIG_ENDIAN)
                d = *cdat1++<<24 | *cdat2++<<16 | *cdat3++<<8 | *cdat4++;
#elif defined(__LITTLE_ENDIAN)
                d = *cdat1++ | *cdat2++<<8 | *cdat3++<<16 | *cdat4++<<24;
#else
#error FIXME: No endianness??
#endif
                fg = fg0;
                bg = bg0;
                for (i = p->var.bits_per_pixel; i--; dest += p->next_plane) {
                    if (bg & 1){
                        if (fg & 1)
                            *(u32 *)dest = 0xffffffff;
                        else
                            *(u32 *)dest = ~d;
                    }else{
                        if (fg & 1)
                            *(u32 *)dest = d;
                        else
                            *(u32 *)dest = 0x00000000;
                    }
                    bg >>= 1;
                    fg >>= 1;
                }
            }
            s += 4;
            dest0 += 4;
            xx += 4;
            count -= 3;
        }
}

void fbcon_ilbm_revc(struct display *p, int xx, int yy)
{
    u8 *dest, *dest0;
    u_int rows, i;
    int mask;

    dest0 = p->screen_base+yy*fontheight(p)*p->next_line+xx;
    mask = p->fgcol ^ p->bgcol;

    /*
     *  This should really obey the individual character's
     *  background and foreground colors instead of simply
     *  inverting.
     */

    for (i = p->var.bits_per_pixel; i--; dest0 += p->next_plane) {
        if (mask & 1) {
            dest = dest0;
            for (rows = fontheight(p); rows--; dest += p->next_line)
                *dest = ~*dest;
        }
        mask >>= 1;
    }
}


    /*
     *  `switch' for the low level operations
     */

struct display_switch fbcon_ilbm = {
    setup:              fbcon_ilbm_setup,
    bmove:              fbcon_ilbm_bmove,
    clear:              fbcon_ilbm_clear,
    putc:               fbcon_ilbm_putc,
    putcs:              fbcon_ilbm_putcs,
    revc:               fbcon_ilbm_revc,
    fontwidthmask:      FONTWIDTH(8)
};


#ifdef MODULE
MODULE_LICENSE("GPL");

int init_module(void)
{
    return 0;
}

void cleanup_module(void)
{}
#endif /* MODULE */


    /*
     *  Visible symbols for modules
     */

EXPORT_SYMBOL(fbcon_ilbm);
EXPORT_SYMBOL(fbcon_ilbm_setup);
EXPORT_SYMBOL(fbcon_ilbm_bmove);
EXPORT_SYMBOL(fbcon_ilbm_clear);
EXPORT_SYMBOL(fbcon_ilbm_putc);
EXPORT_SYMBOL(fbcon_ilbm_putcs);
EXPORT_SYMBOL(fbcon_ilbm_revc);