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timex.h
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1 /*
2  * Copyright (C) 2004-2006 Atmel Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #ifndef __ASM_AVR32_TIMEX_H
9 #define __ASM_AVR32_TIMEX_H
10 
11 /*
12  * This is the frequency of the timer used for Linux's timer interrupt.
13  * The value should be defined as accurate as possible or under certain
14  * circumstances Linux timekeeping might become inaccurate or fail.
15  *
16  * For many system the exact clockrate of the timer isn't known but due to
17  * the way this value is used we can get away with a wrong value as long
18  * as this value is:
19  *
20  * - a multiple of HZ
21  * - a divisor of the actual rate
22  *
23  * 500000 is a good such cheat value.
24  *
25  * The obscure number 1193182 is the same as used by the original i8254
26  * time in legacy PC hardware; the chip is never found in AVR32 systems.
27  */
28 #define CLOCK_TICK_RATE 500000 /* Underlying HZ */
29 
30 typedef unsigned long cycles_t;
31 
32 static inline cycles_t get_cycles (void)
33 {
34  return 0;
35 }
36 
37 #define ARCH_HAS_READ_CURRENT_TIMER
38 
39 #endif /* __ASM_AVR32_TIMEX_H */