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/* Clock_init()
*
*
* This is modified by Doug McBride to get it to work for the MC68EC040
* IDP board. The below comments are kept to show that some prior work
* was done in the area and the modifications performed was application
* specific for the IDP board to port it to.
*
* This routine initializes the mc68230 on the MC68EC040 board.
* The tick frequency is 40 milliseconds.
*
* 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 "rtems.h"
#include "clockdrv.h"
#include "bsp.h"
#include "cpu.h"
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
volatile rtems_unsigned32 Clock_driver_ticks;
/* ticks since initialization */
rtems_isr_entry Old_ticker;
extern rtems_configuration_table Configuration;
extern void led_putnum();
void Disable_clock();
#define TIMER_VECTOR 0x4D
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp,
rtems_id tid,
rtems_unsigned32 *rval
)
{
Install_clock( Clock_isr );
}
void ReInstall_clock( clock_isr )
rtems_isr_entry clock_isr;
{
rtems_unsigned32 isrlevel = 0 ;
rtems_interrupt_disable( isrlevel );
(void) set_vector( clock_isr, TIMER_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
/* The following was added for debugging purposes */
void Disable_clock()
{
/* Disable timer */
MC68230_WRITE (TCR, 0x00);
}
void Install_clock( clock_isr )
rtems_isr_entry clock_isr;
{
Clock_driver_ticks = 0;
Clock_isrs = (int)(Configuration.microseconds_per_tick / 1000);
if ( Configuration.ticks_per_timeslice ) {
/* led_putnum('c'); * for debugging purposes */
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, TIMER_VECTOR, 1 );
/* Disable timer for initialization */
MC68230_WRITE (TCR, 0x00);
/* some PI/T initialization stuff here -- see comment in the ckisr.c
file in this directory to understand why I use the values that I do */
/* Set up the interrupt vector on the MC68230 chip:
TIVR = TIMER_VECTOR; */
MC68230_WRITE (TIVR, TIMER_VECTOR);
/* Set CPRH through CPRL to 193 (not 203) decimal for countdown--see ckisr.c
CPRH = 0x00;
CPRM = 0x00;
CPRL = 0xC1; */
MC68230_WRITE (CPRH, 0x00);
MC68230_WRITE (CPRM, 0x00);
MC68230_WRITE (CPRL, 0xC1);
/* Enable timer and use it as an external periodic interrupt generator
TCR = 0xA1; */
/* led_putnum('a'); * for debugging purposes */
MC68230_WRITE (TCR, 0xA1);
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
}
void Clock_exit( void )
{
rtems_unsigned8 data;
if ( Configuration.ticks_per_timeslice ) {
/* disable timer
data = TCR;
TCR = (data & 0xFE); */
MC68230_READ (TCR, data);
MC68230_WRITE (TCR, (data & 0xFE));
/* do not restore old vector */
}
}
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