Subversion Repositories openrisc_2011-10-31

/*  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.OARcorp.com/rtems/license.html.

 *

 *  $Id: ckinit.c,v 1.2 2001-09-27 11:59:50 chris Exp $

 */

#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);

}