/*
* 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).
* Copyright assigned to U.S. Government, 1994.
*
* 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.
*
* $Id$
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.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 rtems_unsigned32 Clock_driver_ticks;
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;
/* Clock_isr --
* This handles the timer interrupt by clearing the timer's interrupt
* flag and announcing the clock tick to the system.
*
* PARAMETERS:
* vector - timer interrupt vector number
*
* RETURNS:
* none
*/
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);
}
/* Clock_exit --
* This shuts down the timer if it was enabled and removes it
* from the MCF5206E interrupt mask.
*
* PARAMETERS:
* none
*
* RETURNS:
* none
*/
void
Clock_exit(void)
{
if (BSP_Configuration.ticks_per_timeslice)
{
/* 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;
}
}
/* Install_clock --
* This initialises timer1 with the BSP timeslice config value
* as a reference and sets up the interrupt handler for clock ticks.
*
* PARAMETERS:
* clock_isr - clock interrupt handler routine
*
* RETURNS:
* none.
*/
static void
Install_clock(rtems_isr_entry clock_isr)
{
Clock_driver_ticks = 0;
if (BSP_Configuration.ticks_per_timeslice)
{
/* 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) = BSP_Configuration.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);
}
}
/* Clock_initialize --
* This is called to setup the clock driver. It calls the hardware
* setup function and make the driver major/minor values available
* for other.
*
* PARAMETERS:
* major - clock device major number
* minor - clock device minor number
* pargp - device driver initialization argument (not used)
*
* RETURNS:
* RTEMS status code
*/
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;
}
/* Clock_control --
* I/O control (IOCTL) function for Clock driver. At this moment this
* just runs the interrupt handler or re-registers the interrupt handler
* on request.
*
* PARAMETERS:
* major - clock major device number
* minor - clock minor device number
* pargp - pointer to IOCTL arguments
*
* RETURNS:
* RTEMS status code
*/
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)
{
/*
* 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(BSP_INTVEC_TIMER1);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
(void) set_vector( args->buffer, BSP_INTVEC_TIMER1, 1 );
rtems_interrupt_enable( isrlevel );
}
}
return RTEMS_SUCCESSFUL;
}
