diff options
Diffstat (limited to 'arch/mips/lib/delay.c')
-rw-r--r-- | arch/mips/lib/delay.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c new file mode 100644 index 000000000000..f69c6b569eb3 --- /dev/null +++ b/arch/mips/lib/delay.c | |||
@@ -0,0 +1,56 @@ | |||
1 | /* | ||
2 | * This file is subject to the terms and conditions of the GNU General Public | ||
3 | * License. See the file "COPYING" in the main directory of this archive | ||
4 | * for more details. | ||
5 | * | ||
6 | * Copyright (C) 1994 by Waldorf Electronics | ||
7 | * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle | ||
8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. | ||
9 | * Copyright (C) 2007 Maciej W. Rozycki | ||
10 | */ | ||
11 | #include <linux/module.h> | ||
12 | #include <linux/param.h> | ||
13 | #include <linux/smp.h> | ||
14 | |||
15 | #include <asm/compiler.h> | ||
16 | #include <asm/war.h> | ||
17 | |||
18 | inline void __delay(unsigned int loops) | ||
19 | { | ||
20 | __asm__ __volatile__ ( | ||
21 | " .set noreorder \n" | ||
22 | " .align 3 \n" | ||
23 | "1: bnez %0, 1b \n" | ||
24 | " subu %0, 1 \n" | ||
25 | " .set reorder \n" | ||
26 | : "=r" (loops) | ||
27 | : "0" (loops)); | ||
28 | } | ||
29 | EXPORT_SYMBOL(__delay); | ||
30 | |||
31 | /* | ||
32 | * Division by multiplication: you don't have to worry about | ||
33 | * loss of precision. | ||
34 | * | ||
35 | * Use only for very small delays ( < 1 msec). Should probably use a | ||
36 | * lookup table, really, as the multiplications take much too long with | ||
37 | * short delays. This is a "reasonable" implementation, though (and the | ||
38 | * first constant multiplications gets optimized away if the delay is | ||
39 | * a constant) | ||
40 | */ | ||
41 | |||
42 | void __udelay(unsigned long us) | ||
43 | { | ||
44 | unsigned int lpj = current_cpu_data.udelay_val; | ||
45 | |||
46 | __delay((us * 0x000010c7 * HZ * lpj) >> 32); | ||
47 | } | ||
48 | EXPORT_SYMBOL(__udelay); | ||
49 | |||
50 | void __ndelay(unsigned long ns) | ||
51 | { | ||
52 | unsigned int lpj = current_cpu_data.udelay_val; | ||
53 | |||
54 | __delay((us * 0x00000005 * HZ * lpj) >> 32); | ||
55 | } | ||
56 | EXPORT_SYMBOL(__ndelay); | ||