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/*
* Clock Driver for MCF5206eLITE board
*
* This driver initailizes timer1 on the MCF5206E as the
* main system clock
*/
/*
* Author: Victor V. Vengerov <vvv@oktet.ru>
*
* Based on work:
* David Fiddes, D.J@fiddes.surfaid.org
* http://www.calm.hw.ac.uk/davidf/coldfire/
*
* COPYRIGHT (c) 1989-1998.
* 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.org/license/LICENSE.
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.h>
#include <rtems/clockdrv.h>
#include "mcf5206/mcf5206e.h"
/*
* 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;
rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;
static rtems_isr
Clock_isr (rtems_vector_number vector)
{
/* Clear pending interrupt... */
*MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
/* Announce the clock tick */
Clock_driver_ticks++;
rtems_clock_tick();
if (rtems_clock_hook != NULL)
rtems_clock_hook(vector);
}
static void
Clock_exit(void)
{
/* disable all timer1 interrupts */
*MCF5206E_IMR(MBAR) |= MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1);
/* reset timer1 */
*MCF5206E_TMR(MBAR,1) = MCF5206E_TMR_ICLK_STOP;
/* clear pending */
*MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
}
static void
Install_clock(rtems_isr_entry clock_isr)
{
Clock_driver_ticks = 0;
/* Configure timer1 interrupts */
*MCF5206E_ICR(MBAR,MCF5206E_INTR_TIMER_1) =
MCF5206E_ICR_AVEC |
((BSP_INTLVL_TIMER1 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) |
((BSP_INTPRIO_TIMER1 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP);
/* Register the interrupt handler */
set_vector(clock_isr, BSP_INTVEC_TIMER1, 1);
/* Reset timer 1 */
*MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST;
*MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_ICLK_STOP;
*MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST;
*MCF5206E_TCN(MBAR, 1) = 0; /* Reset counter */
*MCF5206E_TER(MBAR, 1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
/* Set Timer 1 prescaler so that it counts in microseconds */
*MCF5206E_TMR(MBAR, 1) =
(((BSP_SYSTEM_FREQUENCY/1000000 - 1) << MCF5206E_TMR_PS_S) &
MCF5206E_TMR_PS) |
MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR |
MCF5206E_TMR_RST;
/* Set the timer timeout value from the BSP config */
*MCF5206E_TRR(MBAR, 1) = rtems_configuration_get_microseconds_per_tick() - 1;
/* Feed system frequency to the timer */
*MCF5206E_TMR(MBAR, 1) |= MCF5206E_TMR_ICLK_MSCLK;
/* Enable timer 1 interrupts */
*MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1);
/* Register the driver exit procedure so we can shutdown */
atexit(Clock_exit);
}
void _Clock_Initialize( void )
{
Install_clock (Clock_isr);
}
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