/* * 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> .text .LC0: .word loops_per_jiffy /* * 0 <= r0 <= 2000 */ ENTRY(__udelay) mov r2, #0x6800 orr r2, r2, #0x00db mul r0, r2, r0 ENTRY(__const_udelay) @ 0 <= r0 <= 0x01ffffff ldr r2, .LC0 ldr r2, [r2] @ max = 0x0fffffff mov r0, r0, lsr #11 @ max = 0x00003fff mov r2, r2, lsr #11 @ max = 0x0003ffff mul r0, r2, r0 @ max = 2^32-1 movs r0, r0, lsr #6 RETINSTR(moveq,pc,lr) /* * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32 * * 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)