/* Clock_init()
*
* This routine initializes the Tick Timer 2 on the MVME147 board.
* 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.
*
* MVME147 port for TNI - Telecom Bretagne
* by Dominique LE CAMPION (Dominique.LECAMPION@enst-bretagne.fr)
* May 1996
*
* $Id$
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.h>
#define MS_COUNT 65376 /* 1ms */
/* MS_COUNT = 0x10000 - 1e-3/6.25e-6 */
#define CLOCK_INT_LEVEL 6 /* T2's interrupt level */
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
volatile rtems_unsigned32 Clock_driver_ticks; /* ticks since initialization */
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_minor_number rtems_clock_minor;
/*
* ISR Handler
*/
rtems_isr Clock_isr(rtems_vector_number vector)
{
Clock_driver_ticks += 1;
pcc->timer2_int_control |= 0x80; /* Acknowledge interr. */
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, TIMER_2_VECTOR, 1 );
pcc->timer2_int_control = 0x00; /* Disable T2 Interr. */
pcc->timer2_preload = MS_COUNT;
/* write preload value */
pcc->timer2_control = 0x07; /* clear T2 overflow counter, enable counter */
pcc->timer2_int_control = CLOCK_INT_LEVEL|0x08;
/* Enable Timer 2 and set its int. level */
atexit( Clock_exit );
}
}
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
pcc->timer2_int_control = 0x00; /* Disable T2 Interr. */
}
}
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(TIMER_2_VECTOR);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
(void) set_vector( args->buffer, TIMER_2_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}
