delay.c
1.14 KB
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/*
* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
* Mostly copied from arch/x86/lib/delay.c
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <asm/param.h>
void __delay(unsigned long loops)
{
asm volatile(
"test %0,%0\n"
"jz 3f\n"
"jmp 1f\n"
".align 16\n"
"1: jmp 2f\n"
".align 16\n"
"2: dec %0\n"
" jnz 2b\n"
"3: dec %0\n"
: /* we don't need output */
: "a" (loops)
);
}
EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
int d0;
xloops *= 4;
asm("mull %%edx"
: "=d" (xloops), "=&a" (d0)
: "1" (xloops), "0"
(loops_per_jiffy * (HZ/4)));
__delay(++xloops);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
}
EXPORT_SYMBOL(__ndelay);