/* Clock_initialize
*
* This routine initializes the Motorola MFP 68901 on the
* FORCE CPU386 board. The tick frequency is 1 millisecond.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* 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>
#define CLOCK_VECTOR 0x38
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
volatile rtems_unsigned32 Clock_driver_ticks;
rtems_isr_entry Old_ticker;
void Clock_exit( void );
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_major_number rtems_clock_minor = 0;
/*
* This is the ISR handler.
*/
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/* enable_tracing(); */
Clock_driver_ticks += 1;
if ( Clock_isrs == 1 ) {
rtems_clock_tick();
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
}
else
Clock_isrs -= 1;
}
void Install_clock(
rtems_isr_entry clock_isr
)
{
Clock_driver_ticks = 0;
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = ( rtems_isr_entry ) set_vector( clock_isr, CLOCK_VECTOR, 1 );
outport_byte( TBCR, 0x14 ); /* reset it, delay mode, 50X */
outport_byte( TBDR, 0x50 ); /* 1 millisecond */
outport_byte( IERA, 0x41 ); /* enable interrupt for B */
}
atexit( Clock_exit );
}
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
outport_byte( TBCR, 0x00 ); /* initial value */
outport_byte( IERA, 0x40 ); /* disable interrupt */
/* ??? Is "do not restore old vector" causing problems? */
}
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( 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_VECTOR);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
(void) set_vector( args->buffer, CLOCK_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}
