/* ckinit.c
*
* This file provides a template for the clock device driver initialization.
*
* 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.
*
* $Id$
*/
#ifndef lint
static char _sccsid[] = "@(#)ckinit.c 03/15/96 1.1\n";
#endif
#include <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>
#include "clock.h"
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */
void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );
/*
* The interrupt vector number associated with the clock tick device
* driver.
*/
#define CLOCK_VECTOR 14
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile rtems_unsigned32 Clock_driver_ticks;
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/*
* The previous ISR on this clock tick interrupt vector.
*/
rtems_isr_entry Old_ticker;
void Clock_exit( void );
static unsigned32 a29k_timer_rate = 0;
/*
* Isr Handler
*/
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/*
* bump the number of clock driver ticks since initialization
*
* determine if it is time to announce the passing of tick as configured
* to RTEMS through the rtems_clock_tick directive
*
* perform any timer dependent tasks
*/
a29k_clear_timer();
Clock_driver_ticks += 1;
rtems_clock_tick();
}
/* User callback shell (set from Clock_Control) */
static void (*user_callback)(void);
rtems_isr User_Clock_isr(
rtems_vector_number vector
)
{
/* refresh the internal CPU timer */
a29k_clear_timer();
if (user_callback)
user_callback();
}
/*
* Install_clock
*
* Install a clock tick handler and reprograms the chip. This
* is used to initially establish the clock tick.
*/
void Install_clock(
rtems_isr_entry clock_isr
)
{
/*
* Initialize the clock tick device driver variables
*/
Clock_driver_ticks = 0;
/*
* If ticks_per_timeslice is configured as non-zero, then the user
* wants a clock tick.
*/
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
/*
* Hardware specific initialize goes here
*/
a29k_timer_rate = BSP_Configuration.microseconds_per_tick * CLOCKS_PER_MICROSECOND;
a29k_init_timer( a29k_timer_rate );
}
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
/* a29k: turn off the timer interrupts */
a29k_disable_timer();
}
}
/*
* Clock_initialize
*
* Device driver entry point for clock tick driver initialization.
*/
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 );
user_callback = (void (*)(void))args->buffer;
(void) set_vector( User_Clock_isr, CLOCK_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}
