rockbox/firmware/target/arm/olympus/mrobe-100/lcd-as-mr100.S
Rafaël Carré 45c7498f59 FS#11335 by me: make ARM assembly functions thumb-friendly
We can't pop into pc on ARMv4t when using thumb: the T bit won't be
modified if we are returning to a thumb function
Code running on ARMv4t should use the new ldrpc / ldmpc macros instead
of ldr pc, [sp], #4 and ldm(cond) sp!, {regs, pc}
No modification on pure ARM builds and ARMv5+

Note: USE_THUMB is currently never defined, no targets can currently be
built with -mthumb, see FS#6734

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26756 a1c6a512-1295-4272-9138-f99709370657
2010-06-11 04:41:36 +00:00

104 lines
2.8 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2008 by Jens Arnold
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
.text
.align 2
.global lcd_write_data
.type lcd_write_data,%function
lcd_write_data:
ldr r12, =LCD1_BASE
.loop:
ldrb r2, [r0], #1
1:
ldr r3, [r12]
tst r3, #LCD1_BUSY_MASK
bne 1b
str r2, [r12, #0x10]
subs r1, r1, #1
bne .loop
bx lr
.size lcd_write_data,.-lcd_write_data
.global lcd_grey_data
.type lcd_grey_data,%function
/* A high performance function to write grey phase data to the display,
* one or multiple pixels.
*
* Arguments:
* r0 - pixel value data address
* r1 - pixel phase data address
* r2 - pixel block count
*
* Register usage:
* r3/r4 - current block of phases
* r5/r6 - current block of values
* r7 - lcd data accumulator
* r12 - phase signs mask
* lr - lcd bridge address
*/
lcd_grey_data:
stmfd sp!, {r4-r7, lr}
mov r12, #0x80
orr r12, r12, r12, lsl #8
orr r12, r12, r12, lsl #16
ldr lr, =LCD1_BASE
.greyloop:
ldmia r1, {r3-r4}
and r5, r12, r3 /* r5 = 3.......2.......1.......0....... */
and r6, r12, r4 /* r6 = 7.......6.......5.......4....... */
orr r5, r5, r6, lsr #4 /* r5 = 3...7...2...6...1...5...0...4... */
orr r5, r5, r5, lsr #9 /* r5 = 3...7...23..67..12..56..01..45.. */
orr r5, r5, r5, lsr #9 /* r5 = 3...7...23..67..123.567.012.456. */
orr r5, r5, r5, lsr #9 /* r5 = 3...7...23..67..123.567.01234567 */
ldmia r0!, {r6-r7}
bic r3, r3, r12
add r3, r3, r6
bic r4, r4, r12
add r4, r4, r7
stmia r1!, {r3-r4}
1:
ldr r6, [lr]
tst r6, #LCD1_BUSY_MASK
bne 1b
str r5, [lr, #0x10]
subs r2, r2, #1
bne .greyloop
ldmpc regs=r4-r7
.size lcd_grey_data,.-lcd_grey_data