[BACK]Return to delay.S CVS log [TXT][DIR] Up to [Development] / linux-2.6-xfs / arch / arm / lib

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, 5 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.

/*
 *  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)