/* Clock_init()
*
* This routine initializes the timer on the VIC chip on the CVME961.
* The tick frequency is 1 millisecond.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* $Id$
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.h>
#define CLOCK_VECTOR 5
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
i960_isr_entry Old_ticker;
volatile rtems_unsigned32 Clock_driver_ticks;
/* ticks since initialization */
void Clock_exit( void );
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/* this is later in the file to avoid it being inlined */
rtems_isr Clock_isr( rtems_vector_number vector );
void Install_clock(
rtems_isr_entry clock_isr
)
{
volatile unsigned char *victimer;
Clock_driver_ticks = 0;
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = set_vector( clock_isr, CLOCK_VECTOR, 1 );
victimer = (volatile unsigned char *) 0xa00000c3;
*victimer = 0x12;
*victimer = 0x92; /* 1000 HZ */
}
}
void ReInstall_clock(
rtems_isr_entry clock_isr
)
{
(void) set_vector( clock_isr, CLOCK_VECTOR, 1 );
}
void Clock_exit()
{
unsigned char *victimer;
if ( BSP_Configuration.ticks_per_timeslice ) {
victimer = (unsigned char *) 0xa00000c3;
*victimer = 0x12;
i960_mask_intr( 5 );
/* do not restore old vector */
}
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( Clock_isr );
atexit( Clock_exit );
/*
* 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_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', ' '))
{
ReInstall_clock(args->buffer);
}
done:
return RTEMS_SUCCESSFUL;
}
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;
i960_clear_intr( 5 );
}
