File: [Development] / linux-2.6-xfs / arch / arm / lib / delay.S (download)
Revision 1.4, Mon May 29 16:35:25 2006 UTC (11 years, 4 months ago) by nathans.longdrop.melbourne.sgi.com
Branch: MAIN
Changes since 1.3: +12 -8
lines
Merge up to 2.6.17-rc5.
Merge of 2.6.x-xfs-melb:linux:26065a by kenmcd.
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/*
* linux/arch/arm/lib/delay.S
*
* Copyright (C) 1995, 1996 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/param.h>
.text
.LC0: .word loops_per_jiffy
.LC1: .word (2199023*HZ)>>11
/*
* r0 <= 2000
* lpj <= 0x01ffffff (max. 3355 bogomips)
* HZ <= 1000
*/
ENTRY(__udelay)
ldr r2, .LC1
mul r0, r2, r0
ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
ldr r2, .LC0
ldr r2, [r2] @ max = 0x01ffffff
mov r0, r0, lsr #14 @ max = 0x0001ffff
mov r2, r2, lsr #10 @ max = 0x00007fff
mul r0, r2, r0 @ max = 2^32-1
movs r0, r0, lsr #6
RETINSTR(moveq,pc,lr)
/*
* loops = r0 * HZ * loops_per_jiffy / 1000000
*
* Oh, if only we had a cycle counter...
*/
@ Delay routine
ENTRY(__delay)
subs r0, r0, #1
#if 0
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
#endif
bhi __delay
RETINSTR(mov,pc,lr)