From 8ef38186faea3d9b5e6f0f1242f668cb7e7a3d52 Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Mon, 12 Jun 2000 19:57:02 +0000 Subject: Patch from John Cotton , Charles-Antoine Gauthier , and Darlene A. Stewart to add support for a number of very significant things: + BSPs for many variations on the Motorola MBX8xx board series + Cache Manager including initial support for m68040 and PowerPC + Rework of mpc8xx libcpu code so all mpc8xx CPUs now use same code base. + Rework of eth_comm BSP to utiltize above. John reports this works on the 821 and 860 --- c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c | 104 ++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c (limited to 'c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c') diff --git a/c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c b/c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c new file mode 100644 index 0000000000..50c2a3e00a --- /dev/null +++ b/c/src/lib/libcpu/powerpc/mpc8xx/timer/timer.c @@ -0,0 +1,104 @@ +/* timer.c + * + * This file manages the interval timer on the PowerPC MPC8xx. + * NOTE: This is not the PIT, but rather the RTEMS interval + * timer + * We shall use the bottom 32 bits of the timebase register, + * + * The following was in the 403 version of this file. I don't + * know what it means. JTM 5/19/98 + * NOTE: It is important that the timer start/stop overhead be + * determined when porting or modifying this code. + * + * Author: Jay Monkman (jmonkman@frasca.com) + * Copywright (C) 1998 by Frasca International, Inc. + * + * Derived from c/src/lib/libcpu/ppc/ppc403/timer/timer.c: + * + * Author: Andrew Bray + * + * COPYRIGHT (c) 1995 by i-cubed ltd. + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of i-cubed limited not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * i-cubed limited makes no representations about the suitability + * of this software for any purpose. + * + * Derived from c/src/lib/libcpu/hppa1_1/timer/timer.c: + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + * + * $Id$ + */ + +#include +#include +#include + +extern rtems_cpu_table Cpu_table; /* owned by BSP */ + +static volatile rtems_unsigned32 Timer_starting; +static rtems_boolean Timer_driver_Find_average_overhead; + +/* + * This is so small that this code will be reproduced where needed. + */ +static inline rtems_unsigned32 get_itimer(void) +{ + rtems_unsigned32 ret; + + asm volatile ("mftb %0" : "=r" ((ret))); /* TBLO */ + + return ret; +} + +void Timer_initialize(void) +{ + /* set interrupt level and enable timebase. This should never */ + /* generate an interrupt however. */ + m8xx.tbscr |= M8xx_TBSCR_TBIRQ(4) | M8xx_TBSCR_TBE; + + Timer_starting = get_itimer(); +} + +int Read_timer(void) +{ + rtems_unsigned32 clicks; + rtems_unsigned32 total; + + clicks = get_itimer(); + + total = clicks - Timer_starting; + + if ( Timer_driver_Find_average_overhead == 1 ) + return total; /* in XXX microsecond units */ + + else { + if ( total < Cpu_table.timer_least_valid ) { + return 0; /* below timer resolution */ + } + return (total - Cpu_table.timer_average_overhead); + } +} + +rtems_status_code Empty_function(void) +{ + return RTEMS_SUCCESSFUL; +} + +void Set_find_average_overhead(rtems_boolean find_flag) +{ + Timer_driver_Find_average_overhead = find_flag; +} -- cgit v1.2.3