forked from Imagelibrary/rtems
126 lines
3.3 KiB
C
126 lines
3.3 KiB
C
/*
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* Clock Driver for MCF5272 CPU
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*
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* This driver initailizes timer1 on the MCF5272 as the
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* main system clock
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*/
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/*
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* Copyright 2004 Cogent Computer Systems
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* Author: Jay Monkman <jtm@lopingdog.com>
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*
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* Based on MCF5206 clock driver by
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* Victor V. Vengerov <vvv@oktet.ru>
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*
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* Based on work:
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* David Fiddes, D.J@fiddes.surfaid.org
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* http://www.calm.hw.ac.uk/davidf/coldfire/
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*
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* COPYRIGHT (c) 1989-1998.
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* On-Line Applications Research Corporation (OAR).
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*
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* The license and distribution terms for this file may be
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* found in the file LICENSE in this distribution or at
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* http://www.rtems.org/license/LICENSE.
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*/
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#include <stdlib.h>
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#include <bsp.h>
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#include <rtems/libio.h>
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#include <mcf5272/mcf5272.h>
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#include <rtems/clockdrv.h>
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/*
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* Clock_driver_ticks is a monotonically increasing counter of the
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* number of clock ticks since the driver was initialized.
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*/
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volatile uint32_t Clock_driver_ticks;
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rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;
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static rtems_isr
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Clock_isr (rtems_vector_number vector)
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{
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/* Clear pending interrupt... */
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g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_TER_CAP;
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/* Announce the clock tick */
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Clock_driver_ticks++;
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rtems_clock_tick();
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if (rtems_clock_hook != NULL) {
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rtems_clock_hook(vector);
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}
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}
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void
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Clock_exit(void)
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{
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uint32_t icr;
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/* disable all timer1 interrupts */
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icr = g_intctrl_regs->icr1;
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icr = icr & ~(MCF5272_ICR1_TMR1_MASK | MCF5272_ICR1_TMR1_PI);
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icr |= (MCF5272_ICR1_TMR1_IPL(0) | MCF5272_ICR1_TMR1_PI);
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g_intctrl_regs->icr1 = icr;
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/* reset timer1 */
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g_timer_regs->tmr1 = MCF5272_TMR_CLK_STOP;
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/* clear pending */
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g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_TER_CAP;
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}
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static void
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Install_clock(rtems_isr_entry clock_isr)
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{
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uint32_t icr;
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Clock_driver_ticks = 0;
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/* Register the interrupt handler */
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set_vector(clock_isr, BSP_INTVEC_TMR1, 1);
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/* Reset timer 1 */
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g_timer_regs->tmr1 = MCF5272_TMR_RST;
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g_timer_regs->tmr1 = MCF5272_TMR_CLK_STOP;
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g_timer_regs->tmr1 = MCF5272_TMR_RST;
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g_timer_regs->tcn1 = 0; /* reset counter */
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g_timer_regs->ter1 = MCF5272_TER_REF | MCF5272_TER_CAP;
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/* Set Timer 1 prescaler so that it counts in microseconds */
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g_timer_regs->tmr1 = (
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((((BSP_SYSTEM_FREQUENCY / 1000000) - 1) << MCF5272_TMR_PS_SHIFT) |
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MCF5272_TMR_CE_DISABLE |
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MCF5272_TMR_ORI |
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MCF5272_TMR_FRR |
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MCF5272_TMR_CLK_MSTR |
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MCF5272_TMR_RST));
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/* Set the timer timeout value from the BSP config */
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g_timer_regs->trr1 = rtems_configuration_get_microseconds_per_tick() - 1;
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/* Feed system frequency to the timer */
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g_timer_regs->tmr1 |= MCF5272_TMR_CLK_MSTR;
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/* Configure timer1 interrupts */
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icr = g_intctrl_regs->icr1;
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icr = icr & ~(MCF5272_ICR1_TMR1_MASK | MCF5272_ICR1_TMR1_PI);
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icr |= (MCF5272_ICR1_TMR1_IPL(BSP_INTLVL_TMR1) | MCF5272_ICR1_TMR1_PI);
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g_intctrl_regs->icr1 = icr;
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/* Register the driver exit procedure so we can shutdown */
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atexit(Clock_exit);
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}
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rtems_device_driver
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Clock_initialize(
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rtems_device_major_number major,
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rtems_device_minor_number minor,
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void *pargp
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)
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{
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Install_clock (Clock_isr);
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return RTEMS_SUCCESSFUL;
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}
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