no_bsp/clock/ckinit.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*
0004  *  This file provides a template for the clock device driver initialization.
0005  *
0006  *  If possible, please use the dev/clock/clockimpl.h method for instantiating
0007  *  a clock driver.
0008  */
0009
0010 /*
0011  *  COPYRIGHT (c) 1989-2014.
0012  *  On-Line Applications Research Corporation (OAR).
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #include <stdlib.h>
0037
0038 #include <rtems.h>
0039 #include <bsp.h>
0040
0041 void Clock_exit( void );
0042 rtems_isr Clock_isr( rtems_vector_number vector );
0043
0044 /*
0045  *  The interrupt vector number associated with the clock tick device
0046  *  driver.
0047  */
0048 #define CLOCK_VECTOR    4
0049
0050 /*
0051  *  Clock_driver_ticks is a monotonically increasing counter of the
0052  *  number of clock ticks since the driver was initialized.
0053  */
0054 volatile uint32_t         Clock_driver_ticks;
0055
0056 /*
0057  *  Clock_isrs is the number of clock ISRs until the next invocation of
0058  *  the RTEMS clock tick routine.  The clock tick device driver
0059  *  gets an interrupt once a millisecond and counts down until the
0060  *  length of time between the user configured microseconds per tick
0061  *  has passed.
0062  */
0063 uint32_t         Clock_isrs;              /* ISRs until next tick */
0064
0065 /*
0066  *  The previous ISR on this clock tick interrupt vector.
0067  */
0068 rtems_isr_entry  Old_ticker;
0069
0070 static void Clock_exit( void );
0071
0072 /*
0073  *  Isr Handler
0074  */
0075 static rtems_isr Clock_isr(
0076   rtems_vector_number vector
0077 )
0078 {
0079   /*
0080    * bump the number of clock driver ticks since initialization
0081    *
0082    * determine if it is time to announce the passing of tick as configured
0083    * to RTEMS through the rtems_clock_tick directive
0084    *
0085    * perform any timer dependent tasks
0086    */
0087 }
0088
0089 /*
0090  *  Install_clock
0091  *
0092  *  Install a clock tick handler and reprograms the chip.  This
0093  *  is used to initially establish the clock tick.
0094  */
0095 void Install_clock(
0096   rtems_isr_entry clock_isr
0097 )
0098 {
0099   /*
0100    *  Initialize the clock tick device driver variables
0101    */
0102
0103   Clock_driver_ticks = 0;
0104   Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
0105
0106   Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
0107   /*
0108    *  Hardware specific initialize goes here
0109    */
0110
0111   /* XXX */
0112
0113   /*
0114    *  Schedule the clock cleanup routine to execute if the application exits.
0115    */
0116
0117   atexit( Clock_exit );
0118 }
0119
0120 /*
0121  *  Clean up before the application exits
0122  */
0123
0124 void Clock_exit( void )
0125 {
0126   /* XXX: turn off the timer interrupts */
0127
0128   /* XXX: If necessary, restore the old vector */
0129 }
0130
0131 void _Clock_Initialize( void )
0132 {
0133   Install_clock( Clock_isr );
0134 }