| Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 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 | extern int read_current_timer(unsigned long *timer_value); |
| 38 | #define ARCH_HAS_READ_CURRENT_TIMER 1 |
| 39 | |
| 40 | #endif /* __ASM_AVR32_TIMEX_H */ |