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
|
/*
* linux/arch/unicore32/lib/delay.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* 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>
#include <asm/param.h>
.text
.LC0: .word loops_per_jiffy
.LC1: .word (2199023*HZ)>>11
/*
* r0 <= 2000
* lpj <= 0x01ffffff (max. 3355 bogomips)
* HZ <= 1000
*/
ENTRY(__udelay)
ldw r2, .LC1
mul r0, r2, r0
ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
ldw r2, .LC0
ldw r2, [r2] @ max = 0x01ffffff
mov r0, r0 >> #14 @ max = 0x0001ffff
mov r2, r2 >> #10 @ max = 0x00007fff
mul r0, r2, r0 @ max = 2^32-1
mov.a r0, r0 >> #6
cmoveq pc, lr
/*
* loops = r0 * HZ * loops_per_jiffy / 1000000
*
* Oh, if only we had a cycle counter...
*/
@ Delay routine
ENTRY(__delay)
sub.a r0, r0, #2
bua __delay
mov pc, lr
ENDPROC(__udelay)
ENDPROC(__const_udelay)
ENDPROC(__delay)
|
