tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/arch/arm26/lib/delay.S
3 *
4 * Copyright (C) 1995, 1996 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <asm/assembler.h>
12 .text
13
14LC0: .word loops_per_jiffy
15
16/*
17 * 0 <= r0 <= 2000
18 */
19ENTRY(udelay)
20 mov r2, #0x6800
21 orr r2, r2, #0x00db
22 mul r1, r0, r2
23 ldr r2, LC0
24 ldr r2, [r2]
25 mov r1, r1, lsr #11
26 mov r2, r2, lsr #11
27 mul r0, r1, r2
28 movs r0, r0, lsr #6
29 RETINSTR(moveq,pc,lr)
30
31/*
32 * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
33 *
34 * Oh, if only we had a cycle counter...
35 */
36
37@ Delay routine
38ENTRY(__delay)
39 subs r0, r0, #1
40#if 0
41 RETINSTR(movls,pc,lr)
42 subs r0, r0, #1
43 RETINSTR(movls,pc,lr)
44 subs r0, r0, #1
45 RETINSTR(movls,pc,lr)
46 subs r0, r0, #1
47 RETINSTR(movls,pc,lr)
48 subs r0, r0, #1
49 RETINSTR(movls,pc,lr)
50 subs r0, r0, #1
51 RETINSTR(movls,pc,lr)
52 subs r0, r0, #1
53 RETINSTR(movls,pc,lr)
54 subs r0, r0, #1
55#endif
56 bhi __delay
57 RETINSTR(mov,pc,lr)