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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.OARcorp.com/rtems/license.html.
*
*
* $Id$
*/
#include <rtems.h>
#include <rtems/clockdrv.h>
#include <rtems/libio.h>
#include <stdlib.h>
#include <bsp.h>
#include <irq.h>
#include <at91rm9200.h>
#include <at91rm9200_pmc.h>
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
volatile uint32_t Clock_driver_ticks;
static unsigned long st_pimr_reload;
rtems_isr clock_isr(rtems_vector_number vector);
void Clock_exit(void);
static void clock_isr_on(const rtems_irq_connect_data *unused);
static void clock_isr_off(const rtems_irq_connect_data *unused);
static int clock_isr_is_on(const rtems_irq_connect_data *irq);
/* Replace the first value with the clock's interrupt name. */
rtems_irq_connect_data clock_isr_data = {AT91RM9200_INT_SYSIRQ,
(rtems_irq_hdl)clock_isr,
clock_isr_on,
clock_isr_off,
clock_isr_is_on,
3, /* unused for ARM cpus */
0 }; /* unused for ARM cpus */
rtems_isr clock_isr(rtems_vector_number vector)
{
uint32_t st_str;
Clock_driver_ticks++;
/* read the status to clear the int */
st_str = ST_REG(ST_SR);
/* reload the timer value */
ST_REG(ST_PIMR) = st_pimr_reload;
rtems_clock_tick();
}
void Install_clock(rtems_isr_entry clock_isr)
{
uint32_t st_str;
int slck;
Clock_driver_ticks = 0;
BSP_install_rtems_irq_handler(&clock_isr_data);
/* the system timer is driven from SLCK */
slck = at91rm9200_get_slck();
st_pimr_reload = ((BSP_Configuration.microseconds_per_tick * slck) /
1000000);
/* 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;
atexit( Clock_exit );
}
void Clock_exit( void )
{
BSP_remove_rtems_irq_handler(&clock_isr_data);
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( clock_isr );
rtems_clock_major = major;
rtems_clock_minor = minor;
return RTEMS_SUCCESSFUL;
}
rtems_device_driver Clock_control(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
uint32_t isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args == 0) {
return RTEMS_SUCCESSFUL;
}
if (args->command == rtems_build_name('I', 'S', 'R', ' ')) {
clock_isr(0);
} else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) {
rtems_interrupt_disable(isrlevel);
BSP_install_rtems_irq_handler(args->buffer);
rtems_interrupt_enable(isrlevel);
}
return RTEMS_SUCCESSFUL;
}
/**
* 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;
return;
}
/**
* 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;
}
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