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RIOT/core/include/hwtimer.h
Martin Lenders 07e8ac9c19 Remove swtimer
see #4
2013-04-11 15:24:15 +02:00

130 lines
3.6 KiB
C

/**
* Hardware timer interface
*
* The Hardware timers are directly mapped to hardware timers with minimum
* latency. They are intended for short intervals and to be used in time
* critical low-level drivers (e.g. radio). hwtimer callbacks are run in the
* interrupt context and must use the shortest possible execution time (e.g.
* set a flag and trigger a worker thread).
*
* <b>hwtimer must not be used within applications</b>, use \ref vtimer
* instead.
*
* @defgroup hwtimer Hardware timer
* @ingroup kernel
* @{
* @file
*
* @author Freie Universität Berlin, Computer Systems & Telematics
* @author Heiko Will
* @author Kaspar Schleiser <kaspar@schleiser.de>
* @author Michael Baar
*
* Copyright (C) 2010 Freie Universität Berlin
*
* This file subject to the terms and conditions of the GNU General Public
* License. See the file LICENSE in the top level directory for more details.
*/
#ifndef __HWTIMER_H
#define __HWTIMER_H
#include <stdint.h>
#include <hwtimer_cpu.h>
/**
* @def HWTIMER_SPEED
* @brief Number of kernel timer ticks per second
*/
#ifndef HWTIMER_SPEED
#warning "HWTIMER_SPEED undefined. Set HWTIMER_SPEED to number of ticks per second for the current architecture."
#endif
/**
* @brief Convert microseconds to kernel timer ticks
* @param[in] us number of microseconds
* @return kernel timer ticks
*/
#define HWTIMER_TICKS(us) (us / (1000000L / HWTIMER_SPEED))
/**
* @brief Convert ticks to microseconds
* @param[in] ticks number of ticks
* @return microseconds
*/
#define HWTIMER_TICKS_TO_US(ticks) (ticks * (1000000L/HWTIMER_SPEED))
/**
* @def HWTIMER_MAXTICKS
* @brief Maximum hwtimer tick count (before overflow)
*/
#ifndef HWTIMER_MAXTICKS
#warning "HWTIMER_MAXTICKS undefined. Set HWTIMER_MAXTICKS to maximum number of ticks countable on the current architecture."
#endif
/**
* @brief microseconds before hwtimer overflow
*/
#define HWTIMER_OVERFLOW_MICROS() (1000000L / HWTIMER_SPEED * HWTIMER_MAXTICKS)
typedef uint32_t timer_tick_t;
void hwtimer_init(void);
void hwtimer_init_comp(uint32_t fcpu);
/**
* @brief Set a kernel timer
* @param[in] offset Offset until callback invocation in timer ticks
* @param[in] callback Callback function
* @param[in] ptr Argument to callback function
* @return timer id
*/
int hwtimer_set(unsigned long offset, void (*callback)(void*), void *ptr);
/**
* @brief Set a kernel timer
* @param[in] absolute Absolute timer counter value for invocation of handler
* @param[in] callback Callback function
* @param[in] ptr Argument to callback function
* @return timer id
*/
int hwtimer_set_absolute(unsigned long absolute, void (*callback)(void*), void *ptr);
/**
* @brief Remove a kernel timer
* @param[in] t Id of timer to remove
* @retval 1 on success
*/
int hwtimer_remove(int t);
/**
* @brief Delay current thread
* @param[in] ticks Number of kernel ticks to delay
*/
void hwtimer_wait(unsigned long ticks);
/**
* @brief Delay current thread, spinning. Use only in interrupts for VERY short delays!
* @param[in] ticks Number of kernel ticks to delay
*/
void hwtimer_spin(unsigned long ticks);
int hwtimer_active(void);
/* internal */
/**
* @brief TODO
* @internal
*/
void hwtimer_cpu_init(void (*handler)(int), uint32_t fcpu);
void hwtimer_t0_disable_interrupt(void);
void hwtimer_t0_enable_interrupt(void);
void hwtimer_t0_set(unsigned long value, short timer);
void hwtimer_t0_unset(short timer);
unsigned long hwtimer_t0_now(void);
unsigned long hwtimer_now(void);
/** @} */
#endif /* __HWTIMER_H */