/* ckinit.c
*
* This file contains the clock driver initialization for the IDT 4650.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
* Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c:
*
* 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.
*
* $Id$
*/
/*
* Rather than deleting this, it is commented out to (hopefully) help
* the submitter send updates.
*
* static char _sccsid[] = "@(#)ckinit.c 08/20/96 1.3\n";
*/
#include <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#define EXT_INT5 0x8000 /* external interrupt 5 */
#include "clock.h"
/* formerly in the BSP */
#if 0
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */
#endif
#define CLOCKS_PER_MICROSECOND \
rtems_cpu_configuration_get_clicks_per_microsecond()
/* to avoid including the bsp */
mips_isr_entry set_vector( rtems_isr_entry, rtems_vector_number, int );
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_MASK EXT_INT5
#define CLOCK_VECTOR 0x7
/*
* 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;
/*
* Clock_isrs is the number of clock ISRs until the next invocation of
* the RTEMS clock tick routine. The clock tick device driver
* gets an interrupt once a millisecond and counts down until the
* length of time between the user configured microseconds per tick
* has passed.
*/
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
/*
* 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 mips_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
*/
/* refresh the internal CPU timer */
mips_set_timer( mips_timer_rate );
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 */
mips_set_timer( mips_timer_rate );
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;
Clock_isrs = rtems_configuration_get_milliseconds_per_tick();
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
/*
* Hardware specific initialize goes here
*/
mips_timer_rate =
rtems_configuration_get_microseconds_per_tick() * CLOCKS_PER_MICROSECOND;
mips_set_timer( mips_timer_rate );
enable_int(CLOCK_VECTOR_MASK);
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
/* mips: turn off the timer interrupts */
disable_int(~CLOCK_VECTOR_MASK);
}
/*
* 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;
}
