/* Clock
*
* This routine generates clock ticks using standard POSIX services.
* The tick frequency is specified by the bsp.
*
* 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 <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>
/*
* In order to get the types and prototypes used in this file under
* Solaris 2.3, it is necessary to pull the following magic.
*/
#if defined(solaris)
#warning "Ignore the undefining __STDC__ warning"
#undef __STDC__
#define __STDC__ 0
#undef _POSIX_C_SOURCE
#endif
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <time.h>
extern rtems_configuration_table Configuration;
void Clock_exit(void);
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;
void
Install_clock(rtems_isr_entry clock_isr)
{
struct itimerval new;
Clock_driver_ticks = 0;
new.it_value.tv_sec = 0;
new.it_value.tv_usec = Configuration.microseconds_per_tick;
new.it_interval.tv_sec = 0;
new.it_interval.tv_usec = Configuration.microseconds_per_tick;
(void)set_vector(clock_isr, SIGALRM, 1);
setitimer(ITIMER_REAL, &new, 0);
atexit(Clock_exit);
}
void
ReInstall_clock(rtems_isr_entry new_clock_isr)
{
rtems_unsigned32 isrlevel = 0;
rtems_interrupt_disable(isrlevel);
(void)set_vector(new_clock_isr, SIGALRM, 1);
rtems_interrupt_enable(isrlevel);
}
void
Clock_isr(int vector)
{
Clock_driver_ticks++;
rtems_clock_tick();
}
/*
* Called via atexit()
* Remove the clock signal
*/
void
Clock_exit(void)
{
struct itimerval new;
struct sigaction act;
/*
* Set the SIGALRM signal to ignore any last
* signals that might come in while we are
* disarming the timer and removing the interrupt
* vector.
*/
act.sa_handler = SIG_IGN;
sigaction(SIGALRM, &act, 0);
new.it_value.tv_sec = 0;
new.it_value.tv_usec = 0;
setitimer(ITIMER_REAL, &new, 0);
(void)set_vector(0, SIGALRM, 1);
}
rtems_device_driver
Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock((rtems_isr_entry) 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_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(SIGALRM);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
ReInstall_clock(args->buffer);
}
done:
return RTEMS_SUCCESSFUL;
}