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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Michael Sevakis
* Based on lcd_write_data for H300 in lcd.S
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
.section .icode,"ax",@progbits
.align 2
.global lcd_write_data
.type lcd_write_data,@function
lcd_write_data:
move.l (4,%sp),%a0 /* data pointer */
move.l (8,%sp),%d0 /* length in words */
add.l %d0,%d0 /* words -> bytes */
add.l %a0,%d0 /* -> end address */
lea.l 0xf0008002,%a1 /* LCD data port */
lea.l (-24,%sp),%sp /* free up some registers */
movem.l %d2-%d6/%a2,(%sp)
move.l %a0,%d1
btst.l #1,%d1 /* already longword aligned? */
beq.b .wd_wordl_end /* yes: skip initial word copy */
/* transfer initial word */
move.w (%a0)+,%d1 /* |????????|????????|rrrrrggg|gggbbbbb| */
move.l %d1,%d2
and.l #0xfffff800,%d2 /* |????????|????????|rrrrr000|00000000| */
add.l %d2,%d1 /* |????????|???????r|rrrr0ggg|gggbbbbb| */
move.l %d1,%d2
lsr.l #8,%d1 /* |00000000|????????|???????r|rrrr0ggg| */
move.w %d1,(%a1)
lsl.l #1,%d2 /* |????????|??????rr|rrr0gggg|ggbbbbb0| */
move.w %d2,(%a1)
.wd_wordl_end: /* now longword aligned */
moveq.l #28,%d1
add.l %a0,%d1
and.l #0xFFFFFFF0,%d1 /* %d1 = second line bound */
cmp.l %d1,%d0 /* at least one full line to send? */
blo.w .wd_long2_start /* no: skip to trailing longword handling */
subq.l #8,%d1
subq.l #8,%d1 /* %d1 = first line bound */
cmp.l %a0,%d1 /* any leading longwords? */
bls.b .wd_long1_end /* no: skip leading long loop */
.wd_long1_loop:
move.l (%a0)+,%d2 /* read longword */
swap %d2 /* unstuff two pixels and correct order */
move.l %d2,%d5
and.l #0xff00ff00,%d5 /* |rrrrrggg|00000000|rrrrrggg|00000000| */
eor.l %d5,%d2 /* |00000000|gggbbbbb|00000000|gggbbbbb| */
lsr.l #8,%d5 /* |00000000|rrrrrggg|00000000|rrrrrggg| */
move.l %d5,%d6
and.l #0x00f800f8,%d5 /* |00000000|rrrrr000|00000000|rrrrr000| */
add.l %d6,%d5 /* |0000000r|rrrr0ggg|0000000r|rrrr0ggg| */
move.w %d5,(%a1)
lsl.l #1,%d2 /* |0000000g|ggbbbbb0|0000000g|ggbbbbb0| */
move.w %d2,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d2
move.w %d2,(%a1)
cmp.l %a0,%d1
bhi.b .wd_long1_loop
.wd_long1_end:
move.l %d0,%a2
lea.l (-14,%a2),%a2
.wd_line_loop:
movem.l (%a0),%d1-%d4 /* burst-read eight words */
lea.l (16,%a0),%a0 /* increment address */
/* transfer four pairs of longs to display */
/* same procedure for each as in leading long loop */
swap %d1
move.l %d1,%d5
and.l #0xff00ff00,%d5
eor.l %d5,%d1
lsr.l #8,%d5
move.l %d5,%d6
and.l #0x00f800f8,%d5
add.l %d6,%d5
move.w %d5,(%a1)
lsl.l #1,%d1
move.w %d1,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d1
move.w %d1,(%a1)
swap %d2
move.l %d2,%d5
and.l #0xff00ff00,%d5
eor.l %d5,%d2
lsr.l #8,%d5
move.l %d5,%d6
and.l #0x00f800f8,%d5
add.l %d6,%d5
move.w %d5,(%a1)
lsl.l #1,%d2
move.w %d2,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d2
move.w %d2,(%a1)
swap %d3
move.l %d3,%d5
and.l #0xff00ff00,%d5
eor.l %d5,%d3
lsr.l #8,%d5
move.l %d5,%d6
and.l #0x00f800f8,%d5
add.l %d6,%d5
move.w %d5,(%a1)
lsl.l #1,%d3
move.w %d3,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d3
move.w %d3,(%a1)
swap %d4
move.l %d4,%d5
and.l #0xff00ff00,%d5
eor.l %d5,%d4
lsr.l #8,%d5
move.l %d5,%d6
and.l #0x00f800f8,%d5
add.l %d6,%d5
move.w %d5,(%a1)
lsl.l #1,%d4
move.w %d4,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d4
move.w %d4,(%a1)
cmp.l %a0,%a2 /* run %a0 up to last line bound */
bhi.w .wd_line_loop
.wd_long2_start:
subq.l #2,%d0 /* account for handling 2 words per loop */
cmp.l %a0,%d0 /* any (trailing longwords? */
bls.b .wd_long2_end /* no: skip trailing longword loop */
.wd_long2_loop:
move.l (%a0)+,%d2 /* read longword */
swap %d2
move.l %d2,%d5
and.l #0xff00ff00,%d5
eor.l %d5,%d2
lsr.l #8,%d5
move.l %d5,%d6
and.l #0x00f800f8,%d5
add.l %d6,%d5
move.w %d5,(%a1)
lsl.l #1,%d2
move.w %d2,(%a1)
swap %d5
move.w %d5,(%a1)
swap %d2
move.w %d2,(%a1)
cmp.l %a0,%d0 /* run %a0 up to last long bound */
bhi.b .wd_long2_loop
.wd_long2_end:
blo.b .wd_word2_end /* no final word: skip */
move.w (%a0),%d1 /* transfer final word */
move.l %d1,%d2
and.l #0xfffff800,%d2
add.l %d2,%d1
move.l %d1,%d2
lsr.l #8,%d1
move.w %d1,(%a1)
lsl.l #1,%d2
move.w %d2,(%a1)
.wd_word2_end:
movem.l (%sp),%d2-%d6/%a2
lea.l (24,%sp),%sp /* restore registers */
rts
/* end lcd_write_data */
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