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
54
55
56
57
|
/*
* linux/arch/arm26/lib/delay.S
*
* Copyright (C) 1995, 1996 Russell King
*
* 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/linkage.h>
#include <asm/assembler.h>
.text
LC0: .word loops_per_jiffy
/*
* 0 <= r0 <= 2000
*/
ENTRY(udelay)
mov r2, #0x6800
orr r2, r2, #0x00db
mul r1, r0, r2
ldr r2, LC0
ldr r2, [r2]
mov r1, r1, lsr #11
mov r2, r2, lsr #11
mul r0, r1, r2
movs r0, r0, lsr #6
RETINSTR(moveq,pc,lr)
/*
* loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
*
* Oh, if only we had a cycle counter...
*/
@ Delay routine
ENTRY(__delay)
subs r0, r0, #1
#if 0
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
RETINSTR(movls,pc,lr)
subs r0, r0, #1
#endif
bhi __delay
RETINSTR(mov,pc,lr)
|
