/* Clock_initialize
*
* This routine initializes the Timer/Counter on the Intel
* 386ex evaluation board.
*
* The tick frequency is 1 millisecond.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* 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.rtems.com/license/LICENSE.
*
* $Id$
*/
#include <bsp.h>
#include <irq.h>
#include <rtems/libio.h>
#include <stdlib.h>
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
static rtems_unsigned32 Clock_initial_isr_value;
volatile rtems_unsigned32 Clock_driver_ticks;
void Clock_exit( void );
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_major_number rtems_clock_minor = 0;
/*
* This is the ISR handler.
*/
void Clock_isr()
{
/* enable_tracing(); */
Clock_driver_ticks += 1;
if ( Clock_isrs == 1 ) {
rtems_clock_tick();
Clock_isrs = Clock_initial_isr_value; /* BSP_Configuration.microseconds_per_tick / 1000;*/
}
else
Clock_isrs -= 1;
}
void ClockOff(const rtems_irq_connect_data* unused)
{
outport_byte (TIMER_CONFIG, 0x80 ); /* disable the counter timer */
}
void ClockOn(const rtems_irq_connect_data* unused)
{
outport_byte (TIMER_CONFIG, 0x00 ); /* enable the counter timer */
}
int ClockIsOn(const rtems_irq_connect_data* unused)
{
return ((i8259s_cache & 0x1) == 0);
}
static rtems_irq_connect_data clockIrqData = {BSP_PERIODIC_TIMER,
Clock_isr,
ClockOn,
ClockOff,
ClockIsOn};
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
unsigned timer_counter_init_value;
unsigned char clock_lsb, clock_msb;
#ifdef BSP_DEBUG
printk("Initializing clock driver in Clock_initialize().\n");
#endif
#ifdef LOAD_RTC_AT_START
/* Initialize clock from on-board real time clock. This breaks the */
/* test code which assumes which assumes the application will do it. */
{
rtems_time_of_day now;
/* External Prototypes */
extern void init_rtc(void); /* defined in 'rtc.c' */
extern long rtc_read(rtems_time_of_day *); /* defined in 'rtc.c' */
#ifdef BSP_DEBUG
printk("Loading clock from on-board real-time clock.\n");
#endif
init_rtc();
if (rtc_read(&now) >= 0)
rtems_clock_set(&now);
}
#endif
Clock_driver_ticks = 0;
Clock_isrs =
Clock_initial_isr_value =
BSP_Configuration.microseconds_per_tick / 1000; /* ticks per clock_isr */
/*
* configure the counter timer ( should be based on microsecs/tick )
* NB. The divisor(Clock_isrs) resolves the is the same number that appears in confdefs.h
* when setting the microseconds_per_tick value.
*/
ClockOff ( &clockIrqData );
timer_counter_init_value = BSP_Configuration.microseconds_per_tick / Clock_isrs;
clock_lsb = (unsigned char)timer_counter_init_value;
clock_msb = timer_counter_init_value >> 8;
outport_byte (TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
outport_byte (TIMER_CNTR0, clock_lsb ); /* load LSB first */
outport_byte (TIMER_CNTR0, clock_msb ); /* then MSB */
if (!BSP_install_rtems_irq_handler (&clockIrqData)) {
printk("Unable to initialize system clock\n");
rtems_fatal_error_occurred(1);
}
/*
* 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();
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
if (!BSP_install_rtems_irq_handler (&clockIrqData)) {
printk("Error installing clock interrupt handler!\n");
rtems_fatal_error_occurred(1);
}
#ifdef BSP_DEBUG
else
printk("Clock installed AGAIN\n");
#endif
}
done:
return RTEMS_SUCCESSFUL;
}
void Clock_exit()
{
ClockOff(&clockIrqData);
BSP_remove_rtems_irq_handler (&clockIrqData);
}
