mirror of https://gitee.com/openkylin/linux.git
39 lines
904 B
C
39 lines
904 B
C
|
#ifndef _H8300_DELAY_H
|
||
|
|
#define _H8300_DELAY_H
|
||
|
|
|
||
|
|
#include <asm/param.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2002 Yoshinori Sato <ysato@sourceforge.jp>
|
||
|
|
*
|
||
|
|
* Delay routines, using a pre-computed "loops_per_second" value.
|
||
|
|
*/
|
||
|
|
|
||
|
|
static inline void __delay(unsigned long loops)
|
||
|
|
{
|
||
|
|
__asm__ __volatile__ ("1:\n\t"
|
||
|
|
"dec.l #1,%0\n\t"
|
||
|
|
"bne 1b"
|
||
|
|
:"=r" (loops):"0"(loops));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* 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)
|
||
|
|
{
|
||
|
|
usecs *= 4295; /* 2**32 / 1000000 */
|
||
|
|
usecs /= (loops_per_jiffy*HZ);
|
||
|
|
if (usecs)
|
||
|
|
__delay(usecs);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* _H8300_DELAY_H */
|