1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
/*
* BK Id: SCCS/s.delay.h 1.7 05/17/01 18:14:24 cort
*/
#ifdef __KERNEL__
#ifndef _PPC_DELAY_H
#define _PPC_DELAY_H
#include <asm/param.h>
/*
* Copyright 1996, Paul Mackerras.
*
* 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.
*/
extern unsigned long loops_per_jiffy;
/* maximum permitted argument to udelay */
#define __MAX_UDELAY 1000000
extern void __delay(unsigned int loops);
/* N.B. the `secs' parameter here is a fixed-point number with
the binary point to the left of the most-significant bit. */
extern __inline__ void __const_udelay(unsigned int secs)
{
unsigned int loops;
__asm__("mulhwu %0,%1,%2" : "=r" (loops) :
"r" (secs), "r" (loops_per_jiffy));
__delay(loops * HZ);
}
/*
* note that 4294 == 2^32 / 10^6, multiplying by 4294 converts from
* microseconds to a 32-bit fixed-point number of seconds.
*/
extern __inline__ void __udelay(unsigned int usecs)
{
__const_udelay(usecs * 4294);
}
extern void __bad_udelay(void); /* deliberately undefined */
#define udelay(n) (__builtin_constant_p(n)? \
((n) > __MAX_UDELAY? __bad_udelay(): __const_udelay((n) * 4294u)) : \
__udelay(n))
#endif /* defined(_PPC_DELAY_H) */
#endif /* __KERNEL__ */
|
