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/* SPDX-License-Identifier: BSD-2-Clause */

/*
 *  This file provides a template for the clock device driver initialization.
 *
 *  If possible, please use the dev/clock/clockimpl.h method for instantiating
 *  a clock driver.
 */

/*
 *  COPYRIGHT (c) 1989-2014.
 *  On-Line Applications Research Corporation (OAR).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdlib.h>

#include <rtems.h>
#include <bsp.h>

void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );

/*
 *  The interrupt vector number associated with the clock tick device
 *  driver.
 */
#define CLOCK_VECTOR    4

/*
 *  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;

/*
 *  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.
 */
uint32_t         Clock_isrs;              /* ISRs until next tick */

/*
 *  The previous ISR on this clock tick interrupt vector.
 */
rtems_isr_entry  Old_ticker;

static void Clock_exit( void );

/*
 *  Isr Handler
 */
static 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
   */
}

/*
 *  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
)
{
  /*
   *  Initialize the clock tick device driver variables
   */

  Clock_driver_ticks = 0;
  Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;

  Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
  /*
   *  Hardware specific initialize goes here
   */

  /* XXX */

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

  atexit( Clock_exit );
}

/*
 *  Clean up before the application exits
 */

void Clock_exit( void )
{
  /* XXX: turn off the timer interrupts */

  /* XXX: If necessary, restore the old vector */
}

void _Clock_Initialize( void )
{
  Install_clock( Clock_isr );
}