source: rtems/c/src/lib/libbsp/nios2/nios2_iss/clock/clock.c @ adf81e9

/*
 * Use SYS_CLK as system clock
 *
 * Copyright (c) 2005-2006 Kolja Waschk, rtemsdev/ixo.de
 *
 *  $Id$
 */

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

#define CLOCK_REGS ((altera_avalon_timer_regs*)NIOS2_IO_BASE(CLOCK_BASE))

/*
 * Periodic interval timer interrupt handler
 */
#define Clock_driver_support_at_tick() \
  do { CLOCK_REGS->status = 0; } while(0)

/*
 * Attach clock interrupt handler
 */
#define Clock_driver_support_install_isr(_new, _old) \
  do { _old = (rtems_isr_entry)set_vector(_new, CLOCK_VECTOR, 1); } while(0)


/*
 * Turn off the clock
 */
#define Clock_driver_support_shutdown_hardware() \
  do { CLOCK_REGS->control = ALTERA_AVALON_TIMER_CONTROL_STOP_MSK; } while(0)

/*
 * Set up the clock hardware
 */
void Clock_driver_support_initialize_hardware(void)
{
  uint32_t period;

  CLOCK_REGS->control = ALTERA_AVALON_TIMER_CONTROL_STOP_MSK;

  period = (CLOCK_FREQ/1000000L)*rtems_configuration_get_microseconds_per_tick() - 1;
  CLOCK_REGS->period_hi = period >> 16;
  CLOCK_REGS->period_lo = period & 0xFFFF;

  CLOCK_REGS->control = ALTERA_AVALON_TIMER_CONTROL_ITO_MSK  |
                        ALTERA_AVALON_TIMER_CONTROL_CONT_MSK |
                        ALTERA_AVALON_TIMER_CONTROL_START_MSK;

  NIOS2_IENABLE(1 << CLOCK_VECTOR);
}

#include "../../../shared/clockdrv_shell.h"