acrn-kernel/include/asm-avr32/timex.h

41 lines
1.2 KiB
C

/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_TIMEX_H
#define __ASM_AVR32_TIMEX_H
/*
* This is the frequency of the timer used for Linux's timer interrupt.
* The value should be defined as accurate as possible or under certain
* circumstances Linux timekeeping might become inaccurate or fail.
*
* For many system the exact clockrate of the timer isn't known but due to
* the way this value is used we can get away with a wrong value as long
* as this value is:
*
* - a multiple of HZ
* - a divisor of the actual rate
*
* 500000 is a good such cheat value.
*
* The obscure number 1193182 is the same as used by the original i8254
* time in legacy PC hardware; the chip is never found in AVR32 systems.
*/
#define CLOCK_TICK_RATE 500000 /* Underlying HZ */
typedef unsigned long cycles_t;
static inline cycles_t get_cycles (void)
{
return 0;
}
extern int read_current_timer(unsigned long *timer_value);
#define ARCH_HAS_READ_CURRENT_TIMER 1
#endif /* __ASM_AVR32_TIMEX_H */