tqm8xx/btimer/btimer.c

0001 /*
0002  * RTEMS TQM8xx BSP
0003  *
0004  * This file contains the console driver.
0005  */
0006
0007 /*
0008  * Copyright (c) 2008 Thomas Doerfler, embedded brains GmbH & Co. KG
0009  * All rights reserved.
0010  *
0011  * The license and distribution terms for this file may be
0012  * found in the file LICENSE in this distribution or at
0013  * http://www.rtems.org/license/LICENSE.
0014  */
0015
0016 /*
0017  * benchmark_timer_initialize()
0018  *
0019  * Use TIMER 1 and TIMER 2 for Timing Test Suite
0020  *
0021  * this is derived from "timer.c" available in the m68k/gen68360 BSP
0022  * adapted by Thomas Doerfler <Thomas.Doerfler@embedded-brains.de>
0023  */
0024
0025 /*
0026  *
0027  *  Input parameters:  NONE
0028  *
0029  *  Output parameters:  NONE
0030  *
0031  *  NOTE: It is important that the timer start/stop overhead be
0032  *        determined when porting or modifying this code.
0033  *
0034  *  COPYRIGHT (c) 1989-1999.
0035  *  On-Line Applications Research Corporation (OAR).
0036  *
0037  *  The license and distribution terms for this file may be
0038  *  found in the file LICENSE in this distribution or at
0039  *  http://www.rtems.org/license/LICENSE.
0040  */
0041
0042 #include <rtems.h>
0043 #include <bsp.h>
0044 #include <rtems/btimer.h>
0045 #include <mpc8xx.h>
0046
0047 bool benchmark_timer_find_average_overhead;
0048
0049 void
0050 benchmark_timer_initialize (void)
0051 {
0052     /*
0053      * Reset timers 1 and 2
0054      */
0055     m8xx.tgcr &= ~0x00FF;
0056     m8xx.tcn1 = 0;
0057     m8xx.tcn2 = 0;
0058     m8xx.ter1 = 0xFFFF;
0059     m8xx.ter2 = 0xFFFF;
0060
0061     /*
0062      * Cascade timers 1 and 2
0063      */
0064     m8xx.tgcr |= M8xx_TGCR_CAS2;
0065
0066     /*
0067      * Configure timers 1 and 2 to a single 32-bit, BUS_clock timer.
0068      */
0069     m8xx.tmr2 = (0 << 8) | 0x2;
0070     m8xx.tmr1 = 0;
0071
0072     /*
0073      * Start the timers
0074      */
0075     m8xx.tgcr |=  0x0011;
0076 }
0077
0078 /*
0079  * Return timer value in microsecond units
0080  */
0081 benchmark_timer_t benchmark_timer_read(void)
0082 {
0083   uint32_t retval;
0084   retval = *(uint32_t*)&m8xx.tcn1;
0085   retval = retval * 1000000LL / BSP_bus_frequency;
0086   return retval;
0087 }
0088
0089 void benchmark_timer_disable_subtracting_average_overhead(
0090   bool find_flag
0091 )
0092 {
0093   benchmark_timer_find_average_overhead = find_flag;
0094 }