diff options
Diffstat (limited to 'arch/openrisc/lib/delay.c')
-rw-r--r-- | arch/openrisc/lib/delay.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/openrisc/lib/delay.c b/arch/openrisc/lib/delay.c new file mode 100644 index 000000000000..01d9740ae6f3 --- /dev/null +++ b/arch/openrisc/lib/delay.c | |||
@@ -0,0 +1,60 @@ | |||
1 | /* | ||
2 | * OpenRISC Linux | ||
3 | * | ||
4 | * Linux architectural port borrowing liberally from similar works of | ||
5 | * others. All original copyrights apply as per the original source | ||
6 | * declaration. | ||
7 | * | ||
8 | * Modifications for the OpenRISC architecture: | ||
9 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> | ||
10 | * | ||
11 | * This program is free software; you can redistribute it and/or | ||
12 | * modify it under the terms of the GNU General Public License | ||
13 | * version 2 as published by the Free Software Foundation | ||
14 | * | ||
15 | * Precise Delay Loops | ||
16 | */ | ||
17 | |||
18 | #include <linux/kernel.h> | ||
19 | #include <linux/module.h> | ||
20 | #include <linux/init.h> | ||
21 | #include <asm/delay.h> | ||
22 | #include <asm/timex.h> | ||
23 | #include <asm/processor.h> | ||
24 | |||
25 | int __devinit read_current_timer(unsigned long *timer_value) | ||
26 | { | ||
27 | *timer_value = mfspr(SPR_TTCR); | ||
28 | return 0; | ||
29 | } | ||
30 | |||
31 | void __delay(unsigned long cycles) | ||
32 | { | ||
33 | cycles_t target = get_cycles() + cycles; | ||
34 | |||
35 | while (get_cycles() < target) | ||
36 | cpu_relax(); | ||
37 | } | ||
38 | EXPORT_SYMBOL(__delay); | ||
39 | |||
40 | inline void __const_udelay(unsigned long xloops) | ||
41 | { | ||
42 | unsigned long long loops; | ||
43 | |||
44 | loops = xloops * loops_per_jiffy * HZ; | ||
45 | |||
46 | __delay(loops >> 32); | ||
47 | } | ||
48 | EXPORT_SYMBOL(__const_udelay); | ||
49 | |||
50 | void __udelay(unsigned long usecs) | ||
51 | { | ||
52 | __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ | ||
53 | } | ||
54 | EXPORT_SYMBOL(__udelay); | ||
55 | |||
56 | void __ndelay(unsigned long nsecs) | ||
57 | { | ||
58 | __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ | ||
59 | } | ||
60 | EXPORT_SYMBOL(__ndelay); | ||