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/*
* Clock Driver for MCF5272 CPU
*
* This driver initailizes timer1 on the MCF5272 as the
* main system clock
*
* Copyright 2004 Cogent Computer Systems
* Author: Jay Monkman <jtm@lopingdog.com>
*
* Based on MCF5206 clock driver by
* 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.com/license/LICENSE.
*
* ckinit.c,v 1.1 2001/10/26 19:32:40 joel Exp
*/
#include <stdlib.h>
#include <bsp.h>
#include <rtems/libio.h>
#include <mcf5272/mcf5272.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;
/*
* 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... */
g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_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 (rtems_configuration_get_ticks_per_timeslice()) {
uint32_t icr;
/* disable all timer1 interrupts */
icr = g_intctrl_regs->icr1;
icr = icr & ~(MCF5272_ICR1_TMR1_MASK | MCF5272_ICR1_TMR1_PI);
icr |= (MCF5272_ICR1_TMR1_IPL(0) | MCF5272_ICR1_TMR1_PI);
g_intctrl_regs->icr1 = icr;
/* reset timer1 */
g_timer_regs->tmr1 = MCF5272_TMR_CLK_STOP;
/* clear pending */
g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_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)
{
uint32_t icr;
Clock_driver_ticks = 0;
if (rtems_configuration_get_ticks_per_timeslice()) {
/* Register the interrupt handler */
set_vector(clock_isr, BSP_INTVEC_TMR1, 1);
/* Reset timer 1 */
g_timer_regs->tmr1 = MCF5272_TMR_RST;
g_timer_regs->tmr1 = MCF5272_TMR_CLK_STOP;
g_timer_regs->tmr1 = MCF5272_TMR_RST;
g_timer_regs->tcn1 = 0; /* reset counter */
g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_TER_CAP;
/* Set Timer 1 prescaler so that it counts in microseconds */
g_timer_regs->tmr1 = (
((((BSP_SYSTEM_FREQUENCY / 1000000) - 1) << MCF5272_TMR_PS_SHIFT) |
MCF5272_TMR_CE_DISABLE |
MCF5272_TMR_ORI |
MCF5272_TMR_FRR |
MCF5272_TMR_CLK_MSTR |
MCF5272_TMR_RST));
/* Set the timer timeout value from the BSP config */
g_timer_regs->trr1 = rtems_configuration_get_microseconds_per_tick() - 1;
/* Feed system frequency to the timer */
g_timer_regs->tmr1 |= MCF5272_TMR_CLK_MSTR;
/* Configure timer1 interrupts */
icr = g_intctrl_regs->icr1;
icr = icr & ~(MCF5272_ICR1_TMR1_MASK | MCF5272_ICR1_TMR1_PI);
icr |= (MCF5272_ICR1_TMR1_IPL(BSP_INTLVL_TMR1) | MCF5272_ICR1_TMR1_PI);
g_intctrl_regs->icr1 = icr;
/* 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;
}
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