delay.h
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/* 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 */