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/*

 *  This file contains the clock driver the Hitachi SH 704X

 *

 *  Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and

 *           Bernd Becker (becker@faw.uni-ulm.de)

 *

 *  COPYRIGHT (c) 1997-1998, FAW Ulm, Germany

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 *

 *

 *  COPYRIGHT (c) 1998.

 *  On-Line Applications Research Corporation (OAR).

 *

 *      Modified to reflect registers of sh7045 processor:

 *      John M. Mills (jmills@tga.com)

 *      TGA Technologies, Inc.

 *      100 Pinnacle Way, Suite 140

 *      Norcross, GA 30071 U.S.A.

 *      August, 1999

 *

 *      This modified file may be copied and distributed in accordance

 *      the above-referenced license. It is provided for critique and

 *      developmental purposes without any warranty nor representation

 *      by the authors or by TGA Technologies.

 *

 *  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.

 *

 *  ckinit.c,v 1.4 2001/10/12 21:00:52 joel Exp

 */

#include <rtems.h>

#include <stdlib.h>

#include <rtems/libio.h>

#include <rtems/score/sh_io.h>

#include <rtems/score/sh.h>

#include <rtems/score/ispsh7045.h>

#include <rtems/score/iosh7045.h>

#define _MTU_COUNTER0_MICROSECOND (Clock_MHZ/16)

#ifndef CLOCKPRIO

#define CLOCKPRIO 10

#endif

#define MTU0_STARTMASK  0xfe

#define MTU0_SYNCMASK   0xfe

#define MTU0_MODEMASK   0xc0

#define MTU0_TCRMASK    0x22 /* bit 7 also used, vs 703x */

#define MTU0_STAT_MASK  0xc0

#define MTU0_IRQMASK    0xfe

#define MTU0_TIERMASK   0x01

#define IPRC_MTU0_MASK  0xff0f

#define MTU0_TIORVAL    0x08

/*

 *  The interrupt vector number associated with the clock tick device

 *  driver.

 */

#define CLOCK_VECTOR MTUA0_ISP_V

/*

 *  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;

static void Clock_exit( void );

static rtems_isr Clock_isr( rtems_vector_number vector );

static rtems_unsigned32 Clock_MHZ ;

/*

 *  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 */

static rtems_unsigned32 Clock_isrs_const;        /* only calculated once */

/*

 * 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;

/*

 *  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

   */

  unsigned8 temp;

  /* reset the flags of the status register */

  temp = read8( MTU_TSR0) & MTU0_STAT_MASK;

  write8( temp, MTU_TSR0);

  Clock_driver_ticks++ ;

  if( Clock_isrs == 1)

    {

      rtems_clock_tick();

      Clock_isrs = Clock_isrs_const;

    }

  else

    {

      Clock_isrs-- ;

    }

}

/*

 *  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

)

{

  unsigned8 temp8 = 0;

  unsigned32 factor = 1000000;

  /*

   *  Initialize the clock tick device driver variables

   */

  Clock_driver_ticks = 0;

  Clock_isrs_const = rtems_configuration_get_microseconds_per_tick() / 10000;

  Clock_isrs = Clock_isrs_const;

  factor /= rtems_configuration_get_microseconds_per_tick(); /* minimalization of integer division error */

  Clock_MHZ = rtems_cpu_configuration_get_clicks_per_second() / factor ;

  rtems_interrupt_catch( Clock_isr, CLOCK_VECTOR, &Old_ticker );

  /*

   *  Hardware specific initialize goes here

   */

  /* stop Timer 0 */

  temp8 = read8( MTU_TSTR) & MTU0_STARTMASK;

  write8( temp8, MTU_TSTR);

  /* set initial counter value to 0 */

  write16( 0, MTU_TCNT0);

  /* Timer 0 runs independent */

  temp8 = read8( MTU_TSYR) & MTU0_SYNCMASK;

  write8( temp8, MTU_TSYR);

  /* Timer 0 normal mode */

  temp8 = read8( MTU_TMDR0) & MTU0_MODEMASK;

  write8( temp8, MTU_TMDR0);

  /* TCNT is cleared by GRA ; internal clock /16 */

  write8( MTU0_TCRMASK , MTU_TCR0);

  /* use GRA without I/O - pins  */

  write8( MTU0_TIORVAL, MTU_TIORL0);

  /* reset flags of the status register */

  temp8 = read8( MTU_TSR0) & MTU0_STAT_MASK;

  write8( temp8, MTU_TSR0);

  /* Irq if is equal GRA */

  temp8 = read8( MTU_TIER0) | MTU0_TIERMASK;

  write8( temp8, MTU_TIER0);

  /* set interrupt priority */

  if( sh_set_irq_priority( CLOCK_VECTOR, CLOCKPRIO ) != RTEMS_SUCCESSFUL)

    rtems_fatal_error_occurred( RTEMS_NOT_CONFIGURED);

  /* set counter limits */

  write16( _MTU_COUNTER0_MICROSECOND, MTU_GR0A);

  /* start counter */

  temp8 = read8( MTU_TSTR) |~MTU0_STARTMASK;

  write8( temp8, MTU_TSTR);

  /*

   *  Schedule the clock cleanup routine to execute if the application exits.

   */

  atexit( Clock_exit );

}

/*

 *  Clean up before the application exits

 */

void Clock_exit( void )

{

  unsigned8 temp8 = 0;

  /* turn off the timer interrupts */

  /* set interrupt priority to 0 */

  if( sh_set_irq_priority( CLOCK_VECTOR, 0 ) != RTEMS_SUCCESSFUL)

    rtems_fatal_error_occurred( RTEMS_UNSATISFIED);

/*

 *   temp16 = read16( MTU_TIER0) & IPRC_MTU0_IRQMASK;

 *   write16( temp16, MTU_TIER0);

 */

  /* stop counter */

  temp8 = read8( MTU_TSTR) & MTU0_STARTMASK;

  write8( temp8, MTU_TSTR);

  /* old vector shall not be installed */

}

/*

 *  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)

    {

      /*

       * 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_isr_entry       ignored ;

          rtems_interrupt_disable( isrlevel );

          rtems_interrupt_catch( args->buffer, CLOCK_VECTOR, &ignored );

          rtems_interrupt_enable( isrlevel );

        }

    }

  return RTEMS_SUCCESSFUL;

}