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/*
* AT91RM9200 clock specific using the System Timer
*
* Copyright (c) 2003 by Cogent Computer Systems
* Written by Mike Kelly <mike@cogcomp.com>
* and Jay Monkman <jtm@lopingdog.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <rtems.h>
#include <rtems/clockdrv.h>
#include <rtems/libio.h>
#include <stdlib.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <at91rm9200.h>
#include <at91rm9200_pmc.h>
static unsigned long st_pimr_reload;
/**
* Enables clock interrupt.
*
* If the interrupt is always on, this can be a NOP.
*/
static void clock_isr_on(const rtems_irq_connect_data *unused)
{
/* enable timer interrupt */
ST_REG(ST_IER) = ST_SR_PITS;
}
/**
* Disables clock interrupts
*
* If the interrupt is always on, this can be a NOP.
*/
static void clock_isr_off(const rtems_irq_connect_data *unused)
{
/* disable timer interrupt */
ST_REG(ST_IDR) = ST_SR_PITS;
}
/**
* Tests to see if clock interrupt is enabled, and returns 1 if so.
* If interrupt is not enabled, returns 0.
*
* If the interrupt is always on, this always returns 1.
*/
static int clock_isr_is_on(const rtems_irq_connect_data *irq)
{
/* check timer interrupt */
return ST_REG(ST_IMR) & ST_SR_PITS;
}
void Clock_isr(rtems_irq_hdl_param arg);
/* Replace the first value with the clock's interrupt name. */
rtems_irq_connect_data clock_isr_data = {
.name = AT91RM9200_INT_SYSIRQ,
.hdl = Clock_isr,
.handle = NULL,
.on = clock_isr_on,
.off = clock_isr_off,
.isOn = clock_isr_is_on,
};
#define Clock_driver_support_install_isr( _new, _old ) \
do { \
(_old) = NULL; \
BSP_install_rtems_irq_handler(&clock_isr_data); \
} while(0)
uint16_t st_pimr_value;
void Clock_driver_support_initialize_hardware(void)
{
uint32_t st_str;
int slck;
/* the system timer is driven from SLCK */
slck = at91rm9200_get_slck();
st_pimr_value = (((rtems_configuration_get_microseconds_per_tick() * slck) +
(1000000/2))/ 1000000);
st_pimr_reload = st_pimr_value;
/* read the status to clear the int */
st_str = ST_REG(ST_SR);
/* set priority */
AIC_SMR_REG(AIC_SMR_SYSIRQ) = AIC_SMR_PRIOR(0x7);
/* set the timer value */
ST_REG(ST_PIMR) = st_pimr_reload;
}
uint32_t bsp_clock_nanoseconds_since_last_tick(void)
{
uint16_t slck_counts;
slck_counts = st_pimr_value - st_pimr_reload;
return (rtems_configuration_get_microseconds_per_tick() * slck_counts * 1000)
/ st_pimr_value;
}
#define Clock_driver_nanoseconds_since_last_tick \
bsp_clock_nanoseconds_since_last_tick
#define Clock_driver_support_at_tick() \
do { \
uint32_t st_str; \
\
/* read the status to clear the int */ \
st_str = ST_REG(ST_SR); \
} while (0)
void Clock_driver_support_shutdown_hardware( void )
{
BSP_remove_rtems_irq_handler(&clock_isr_data);
}
#include "../../../../libbsp/shared/clockdrv_shell.h"
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