/* Clock
*
* This routine generates clock ticks using standard POSIX services.
* The tick frequency is specified by the bsp.
*
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* 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 <bsp.h>
#include <rtems/libio.h>
#include <stdlib.h>
void Clock_exit(void);
volatile rtems_unsigned32 Clock_driver_ticks;
rtems_unsigned32 Clock_driver_vector;
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
void Install_clock(rtems_isr_entry clock_isr)
{
Clock_driver_ticks = 0;
(void) set_vector( clock_isr, Clock_driver_vector, 1 );
_CPU_Start_clock( BSP_Configuration.microseconds_per_tick );
atexit(Clock_exit);
}
void Clock_isr(int vector)
{
Clock_driver_ticks++;
rtems_clock_tick();
}
/*
* Called via atexit()
* Remove the clock signal
*/
void Clock_exit(void)
{
_CPU_Stop_clock();
(void) set_vector( 0, Clock_driver_vector, 1 );
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Clock_driver_vector = _CPU_Get_clock_vector();
Install_clock((rtems_isr_entry) Clock_isr);
/*
* make major/minor avail to others such as shared memory driver
*/
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
)
{
rtems_unsigned32 isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args == 0)
goto done;
/*
* This is hokey, but until we get a defined interface
* to do this, it will just be this simple...
*/
if (args->command == rtems_build_name('I', 'S', 'R', ' '))
{
Clock_isr(Clock_driver_vector);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
(void) set_vector( args->buffer, Clock_driver_vector, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}