/*
* Clock Driver for SH4 simulator (timer interrupt not supported now).
*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
*
* COPYRIGHT (c) 1989-2001.
* 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.rtems.com/license/LICENSE.
*
* $Id$
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.h>
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile uint32_t 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;
rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;
static void
set_clock_period(uint32_t period)
{
asm volatile ("\tmov %0,r0\n"
"\ttrapa\t#4\n"
:
: "r" (period)
: "r0" );
}
/* Clock_isr --
* This handles the timer interrupt by clearing the timer's interrupt
* flag and announcing the clock tick to the system.
*
* PARAMETERS:
* vector - timer interrupt vector number
*
* RETURNS:
* none
*/
rtems_isr
Clock_isr (rtems_vector_number vector)
{
/* Announce the clock tick */
Clock_driver_ticks++;
rtems_clock_tick();
}
/* Clock_exit --
* This shuts down the timer if it was enabled and removes it
* from the interrupt mask.
*
* PARAMETERS:
* none
*
* RETURNS:
* none
*/
void
Clock_exit(void)
{
if (BSP_Configuration.ticks_per_timeslice)
{
/* disable all timer1 interrupts */
set_clock_period(0);
}
}
/* Install_clock --
* This initialises timer1 with the BSP timeslice config value
* as a reference and sets up the interrupt handler for clock ticks.
*
* PARAMETERS:
* clock_isr - clock interrupt handler routine
*
* RETURNS:
* none.
*/
static void
Install_clock(rtems_isr_entry clock_isr)
{
uint32_t period;
Clock_driver_ticks = 0;
if (BSP_Configuration.ticks_per_timeslice)
{
rtems_isr_entry old_isr;
period = Cpu_table.clicks_per_second /
BSP_Configuration.ticks_per_timeslice;
/* Configure timer interrupts */
set_clock_period(period);
/* Register the interrupt handler */
rtems_interrupt_catch(clock_isr, CLOCK_VECTOR, &old_isr);
/* Register the driver exit procedure so we can shutdown */
atexit(Clock_exit);
}
}
/* Clock_initialize --
* This is called to setup the clock driver. It calls the hardware
* setup function and make the driver major/minor values available
* for other.
*
* PARAMETERS:
* major - clock device major number
* minor - clock device minor number
* pargp - device driver initialization argument (not used)
*
* RETURNS:
* RTEMS status code
*/
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;
}
/* Clock_control --
* I/O control (IOCTL) function for Clock driver. At this moment this
* just runs the interrupt handler or re-registers the interrupt handler
* on request.
*
* PARAMETERS:
* major - clock major device number
* minor - clock minor device number
* pargp - pointer to IOCTL arguments
*
* RETURNS:
* RTEMS status code
*/
rtems_device_driver
Clock_control(rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp)
{
uint32_t isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args)
{
rtems_isr_entry old_isr;
/*
* 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 );
rtems_interrupt_catch(Clock_isr, CLOCK_VECTOR, &old_isr);
rtems_interrupt_enable( isrlevel );
}
}
return RTEMS_SUCCESSFUL;
}
