OpenModem/bertos/cpu/arm/drv/timer_at91.h
2014-04-03 22:21:37 +02:00

109 lines
3.2 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
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* Copyright 2007 Develer S.r.l. (http://www.develer.com/)
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*
* \author Francesco Sacchi <batt@develer.com>
*
* \brief Low-level timer module for Atmel AT91 (interface).
*/
#ifndef DRV_AT91_TIMER_H
#define DRV_AT91_TIMER_H
#include <hw/hw_cpufreq.h> /* CPU_FREQ */
#include "cfg/cfg_timer.h" /* CONFIG_TIMER */
#include <cfg/compiler.h> /* uint8_t */
#include <cfg/macros.h> /* BV */
#include <io/arm.h>
/**
* \name Values for CONFIG_TIMER.
*
* Select which hardware timer interrupt to use for system clock and softtimers.
*
* $WIZ$ timer_select = "TIMER_ON_PIT", "TIMER_DEFAULT"
*/
#define TIMER_ON_PIT 1 ///< System timer on Periodic interval timer
#define TIMER_DEFAULT TIMER_ON_PIT ///< Default system timer
/*
* Hardware dependent timer initialization.
*/
#if (CONFIG_TIMER == TIMER_ON_PIT)
/*
* On ARM all system IRQs are handled by the sysirq_dispatcher, so the actual
* timer handler can be treated like any other normal routine.
*/
#define DEFINE_TIMER_ISR void timer_handler(void); \
void timer_handler(void)
#define TIMER_TICKS_PER_SEC 1000
#define TIMER_HW_CNT (CPU_FREQ / (16 * TIMER_TICKS_PER_SEC) - 1)
/** Frequency of the hardware high-precision timer. */
#define TIMER_HW_HPTICKS_PER_SEC (CPU_FREQ / 16)
/** Type of time expressed in ticks of the hardware high-precision timer */
typedef uint32_t hptime_t;
#define SIZEOF_HPTIME_T 4
INLINE void timer_hw_irq(void)
{
/* Reset counters, this is needed to reset timer and interrupt flags */
uint32_t dummy = PIVR;
(void) dummy;
}
INLINE bool timer_hw_triggered(void)
{
return PIT_SR & BV(PITS);
}
INLINE hptime_t timer_hw_hpread(void)
{
/* In the upper part of PIT_PIIR there is unused data */
return PIIR & CPIV_MASK;
}
#else
#error Unimplemented value for CONFIG_TIMER
#endif /* CONFIG_TIMER */
void timer_hw_init(void);
#endif /* DRV_TIMER_AT91_H */