/* ckinit.c
*
* This file provides a template for the clock device driver initialization.
*
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* 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 <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>
#include <c4xio.h>
void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );
rtems_unsigned32 Clock_counter_register_value;
/*
* The interrupt vector number associated with the clock tick device
* driver.
*/
#define CLOCK_VECTOR 9
/*
* 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 );
/*
* Isr Handler
*/
#define FAST_IDLE 1
#if FAST_IDLE
int Clock_in_fast_idle_mode = 0;
#endif
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/*
* The counter register gets reset automatically as well as the
* interrupt occurred flag so we should not have to do anything
* with the hardware.
*/
/*
* Bump the number of clock driver ticks since initialization
*/
Clock_driver_ticks += 1;
rtems_clock_tick();
#if FAST_IDLE
if ( Clock_in_fast_idle_mode ) {
if ( _Thread_Executing == _Thread_Idle && _Thread_Heir != _Thread_Idle ) {
c4x_timer_stop( C4X_TIMER_0 );
c4x_timer_set_counter( C4X_TIMER_0, 0 );
c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value );
c4x_timer_start( C4X_TIMER_0 );
Clock_in_fast_idle_mode = 0;
}
} else {
if ( _Thread_Executing == _Thread_Idle && _Thread_Heir == _Thread_Idle ) {
c4x_timer_stop( C4X_TIMER_0 );
c4x_timer_set_counter( C4X_TIMER_0, 0 );
c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value >> 5 );
c4x_timer_start( C4X_TIMER_0 );
}
}
#endif
}
/*
* 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
)
{
extern int _ClockFrequency;
float tmp;
int tmpi;
/*
* Initialize the clock tick device driver variables
*/
Clock_driver_ticks = 0;
tmpi = ((int) &_ClockFrequency) * 1000000; /* ClockFrequency is in Mhz */
tmp = (float) tmpi / 2.0;
tmp = ((float) BSP_Configuration.microseconds_per_tick / 1000000.0) * (tmp);
Clock_counter_register_value = (unsigned int) tmp;
#if 0
Clock_counter_register_value =
(unsigned32) ((float) BSP_Configuration.microseconds_per_tick /
((float)_ClockFrequency / 2.0)));
#endif
c4x_timer_stop( C4X_TIMER_0 );
c4x_timer_set_counter( C4X_TIMER_0, 0 );
c4x_timer_set_period( C4X_TIMER_0, Clock_counter_register_value );
c4x_timer_start( C4X_TIMER_0 );
c3x_set_ie( c3x_get_ie() | 0x100 );
/*
* If ticks_per_timeslice is configured as non-zero, then the user
* wants a clock tick.
*/
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
/*
* Hardware specific initialize goes here
*/
/* XXX */
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
/* XXX: turn off the timer interrupts */
/* XXX: If necessary, restore the old vector */
}
/*
* 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 );
(void) set_vector( args->buffer, CLOCK_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}
