forked from Imagelibrary/rtems
96 lines
3.1 KiB
C
96 lines
3.1 KiB
C
/* SPDX-License-Identifier: BSD-2-Clause */
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/*
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* This routine initializes the Tick Timer 2 on the MVME147 board.
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* The tick frequency is 1 millisecond.
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*/
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/*
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* COPYRIGHT (c) 1989-1999.
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* On-Line Applications Research Corporation (OAR).
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* MVME147 port for TNI - Telecom Bretagne
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* by Dominique LE CAMPION (Dominique.LECAMPION@enst-bretagne.fr)
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* May 1996
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*/
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#include <stdlib.h>
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#include <bsp.h>
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#include <rtems/clockdrv.h>
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#define MS_COUNT 65376 /* 1ms */
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/* MS_COUNT = 0x10000 - 1e-3/6.25e-6 */
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#define CLOCK_INT_LEVEL 6 /* T2's interrupt level */
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uint32_t Clock_isrs; /* ISRs until next tick */
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volatile uint32_t Clock_driver_ticks; /* ticks since initialization */
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rtems_isr_entry Old_ticker;
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static void Clock_exit( void );
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/*
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* ISR Handler
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*/
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static rtems_isr Clock_isr(rtems_vector_number vector)
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{
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Clock_driver_ticks += 1;
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pcc->timer2_int_control |= 0x80; /* Acknowledge interr. */
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if (Clock_isrs == 1) {
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rtems_clock_tick();
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Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
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}
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else
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Clock_isrs -= 1;
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}
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static void Install_clock(rtems_isr_entry clock_isr )
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{
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Clock_driver_ticks = 0;
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Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
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Old_ticker = (rtems_isr_entry) set_vector( clock_isr, TIMER_2_VECTOR, 1 );
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pcc->timer2_int_control = 0x00; /* Disable T2 Interr. */
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pcc->timer2_preload = MS_COUNT;
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/* write preload value */
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pcc->timer2_control = 0x07; /* clear T2 overflow counter, enable counter */
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pcc->timer2_int_control = CLOCK_INT_LEVEL|0x08;
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/* Enable Timer 2 and set its int. level */
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atexit( Clock_exit );
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}
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void Clock_exit( void )
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{
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pcc->timer2_int_control = 0x00; /* Disable T2 Interr. */
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}
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void _Clock_Initialize( void )
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{
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Install_clock( Clock_isr );
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}
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