udelay.c
1.18 KB
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
/*
* arch/sh/lib64/udelay.c
*
* Delay routines, using a pre-computed "loops_per_jiffy" value.
*
* Copyright (C) 2000, 2001 Paolo Alberelli
* Copyright (C) 2003, 2004 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/sched.h>
#include <asm/param.h>
/*
* Use only for very small delays (< 1 msec).
*
* The active part of our cycle counter is only 32-bits wide, and
* we're treating the difference between two marks as signed. On
* a 1GHz box, that's about 2 seconds.
*/
void __delay(unsigned long loops)
{
long long dummy;
__asm__ __volatile__("gettr tr0, %1\n\t"
"pta $+4, tr0\n\t"
"addi %0, -1, %0\n\t"
"bne %0, r63, tr0\n\t"
"ptabs %1, tr0\n\t":"=r"(loops),
"=r"(dummy)
:"0"(loops));
}
void __const_udelay(unsigned long xloops)
{
__delay(xloops * (HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy));
}
void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
}
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00000005);
}