mcf5206elite/dev/ckinit.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*
0004  *  Clock Driver for MCF5206eLITE board
0005  *
0006  *  This driver initailizes timer1 on the MCF5206E as the
0007  *  main system clock
0008  */
0009
0010 /*
0011  *  Author: Victor V. Vengerov <vvv@oktet.ru>
0012  *
0013  *  Based on work:
0014  *    David Fiddes, D.J@fiddes.surfaid.org
0015  *    http://www.calm.hw.ac.uk/davidf/coldfire/
0016  *
0017  *  COPYRIGHT (c) 1989-1998.
0018  *  On-Line Applications Research Corporation (OAR).
0019  *
0020  * Redistribution and use in source and binary forms, with or without
0021  * modification, are permitted provided that the following conditions
0022  * are met:
0023  * 1. Redistributions of source code must retain the above copyright
0024  *    notice, this list of conditions and the following disclaimer.
0025  * 2. Redistributions in binary form must reproduce the above copyright
0026  *    notice, this list of conditions and the following disclaimer in the
0027  *    documentation and/or other materials provided with the distribution.
0028  *
0029  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0030  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0031  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0032  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0033  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0034  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0035  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0036  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0037  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0038  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0039  * POSSIBILITY OF SUCH DAMAGE.
0040  */
0041
0042 #include <stdlib.h>
0043 #include <bsp.h>
0044 #include <rtems/libio.h>
0045 #include <rtems/clockdrv.h>
0046 #include "mcf5206/mcf5206e.h"
0047
0048 /*
0049  * Clock_driver_ticks is a monotonically increasing counter of the
0050  * number of clock ticks since the driver was initialized.
0051  */
0052 volatile uint32_t   Clock_driver_ticks;
0053
0054 rtems_isr (*rtems_clock_hook)(rtems_vector_number) = NULL;
0055
0056 static rtems_isr
0057 Clock_isr (rtems_vector_number vector)
0058 {
0059   /* Clear pending interrupt... */
0060   *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
0061
0062   /* Announce the clock tick */
0063   Clock_driver_ticks++;
0064   rtems_clock_tick();
0065   if (rtems_clock_hook != NULL)
0066       rtems_clock_hook(vector);
0067 }
0068
0069 static void
0070 Clock_exit(void)
0071 {
0072   /* disable all timer1 interrupts */
0073   *MCF5206E_IMR(MBAR) |= MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1);
0074
0075   /* reset timer1 */
0076   *MCF5206E_TMR(MBAR,1) = MCF5206E_TMR_ICLK_STOP;
0077
0078   /* clear pending */
0079   *MCF5206E_TER(MBAR,1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
0080 }
0081
0082
0083 static void
0084 Install_clock(rtems_isr_entry clock_isr)
0085 {
0086   Clock_driver_ticks = 0;
0087
0088   /* Configure timer1 interrupts */
0089   *MCF5206E_ICR(MBAR,MCF5206E_INTR_TIMER_1) =
0090       MCF5206E_ICR_AVEC |
0091       ((BSP_INTLVL_TIMER1 << MCF5206E_ICR_IL_S) & MCF5206E_ICR_IL) |
0092       ((BSP_INTPRIO_TIMER1 << MCF5206E_ICR_IP_S) & MCF5206E_ICR_IP);
0093
0094   /* Register the interrupt handler */
0095   set_vector(clock_isr, BSP_INTVEC_TIMER1, 1);
0096
0097   /* Reset timer 1 */
0098   *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST;
0099   *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_ICLK_STOP;
0100   *MCF5206E_TMR(MBAR, 1) = MCF5206E_TMR_RST;
0101   *MCF5206E_TCN(MBAR, 1) = 0; /* Reset counter */
0102   *MCF5206E_TER(MBAR, 1) = MCF5206E_TER_REF | MCF5206E_TER_CAP;
0103
0104   /* Set Timer 1 prescaler so that it counts in microseconds */
0105   *MCF5206E_TMR(MBAR, 1) =
0106       (((BSP_SYSTEM_FREQUENCY/1000000 - 1) << MCF5206E_TMR_PS_S) &
0107        MCF5206E_TMR_PS) |
0108       MCF5206E_TMR_CE_NONE | MCF5206E_TMR_ORI | MCF5206E_TMR_FRR |
0109       MCF5206E_TMR_RST;
0110
0111   /* Set the timer timeout value from the BSP config */
0112   *MCF5206E_TRR(MBAR, 1) = rtems_configuration_get_microseconds_per_tick() - 1;
0113
0114   /* Feed system frequency to the timer */
0115   *MCF5206E_TMR(MBAR, 1) |= MCF5206E_TMR_ICLK_MSCLK;
0116
0117   /* Enable timer 1 interrupts */
0118   *MCF5206E_IMR(MBAR) &= ~MCF5206E_INTR_BIT(MCF5206E_INTR_TIMER_1);
0119
0120   /* Register the driver exit procedure so we can shutdown */
0121   atexit(Clock_exit);
0122 }
0123
0124 void _Clock_Initialize( void )
0125 {
0126   Install_clock (Clock_isr);
0127 }