/* delay.h: FRV delay code * * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * 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. */ #ifndef _ASM_DELAY_H #define _ASM_DELAY_H #include <asm/param.h> #include <asm/timer-regs.h> /* * delay loop - runs at __core_clock_speed_HZ / 2 [there are 2 insns in the loop] */ extern unsigned long __delay_loops_MHz; static inline void __delay(unsigned long loops) { asm volatile("1: subicc %0,#1,%0,icc0 \n" " bnc icc0,#2,1b \n" : "=r" (loops) : "0" (loops) : "icc0" ); } /* * Use only for very small delays ( < 1 msec). Should probably use a * lookup table, really, as the multiplications take much too long with * short delays. This is a "reasonable" implementation, though (and the * first constant multiplications gets optimized away if the delay is * a constant) */ extern unsigned long loops_per_jiffy; static inline void udelay(unsigned long usecs) { __delay(usecs * __delay_loops_MHz); } #define ndelay(n) udelay((n) * 5) #endif /* _ASM_DELAY_H */