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authorJoel Sherrill <joel.sherrill@OARcorp.com>2001-10-22 13:42:45 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>2001-10-22 13:42:45 +0000
commit1ec501c567ddc0cd377d6a14766d2306e12ccefc (patch)
treed1aa683bd72fd9a10bd8757153c0093f14f130df /c/src/lib/libcpu/powerpc/mpc8260/timer/timer.c
parent2001-10-22 Joel Sherrill <joel@OARcorp.com> (diff)
downloadrtems-1ec501c567ddc0cd377d6a14766d2306e12ccefc.tar.bz2
2001-10-22 Andy Dachs <a.dachs@sstl.co.uk>
* Added mpc8260 directory. * Modified Makefile.am and configure.in to build the contents * mpc8260/Makefile.am, mpc8260/README, mpc8260/clock/Makefile.am, mpc8260/clock/clock.c, mpc8260/console-generic/Makefile.am, mpc8260/console-generic/console-generic.c, mpc8260/cpm/.cvsignore, mpc8260/cpm/Makefile.am, mpc8260/cpm/brg.c, mpc8260/cpm/cp.c, mpc8260/cpm/dpram.c, mpc8260/exceptions/.cvsignore, mpc8260/exceptions/Makefile.am, mpc8260/exceptions/asm_utils.S, mpc8260/exceptions/raw_exception.c, mpc8260/exceptions/raw_exception.h, mpc8260/include/Makefile.am, mpc8260/include/console.h, mpc8260/include/cpm.h, mpc8260/include/mmu.h, mpc8260/include/mpc8260.h, mpc8260/mmu/Makefile.am, mpc8260/mmu/mmu.c, mpc8260/timer/Makefile.am, mpc8260/timer/timer.c: New files.
Diffstat (limited to '')
-rw-r--r--c/src/lib/libcpu/powerpc/mpc8260/timer/timer.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/powerpc/mpc8260/timer/timer.c b/c/src/lib/libcpu/powerpc/mpc8260/timer/timer.c
new file mode 100644
index 0000000000..19f7abf075
--- /dev/null
+++ b/c/src/lib/libcpu/powerpc/mpc8260/timer/timer.c
@@ -0,0 +1,116 @@
+/* timer.c
+ *
+ * This file manages the interval timer on the PowerPC MPC860.
+ * 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: Andy Dachs <a.dachs@sstl.co.uk>
+ * Surrey Satellite Technlogy Limited
+ * Modified for MPC8260
+ * Derived from c/src/lib/libcpu/powerpc/mpc860/timer/timer.c:
+ *
+ * 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 <andy@i-cubed.co.uk>
+ *
+ * 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) 1989-1999.
+ * On-Line Applications Research Corporation (OAR).
+ *
+ * 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 <rtems.h>
+#include <mpc8260.h>
+
+static volatile rtems_unsigned32 Timer_starting;
+static rtems_boolean Timer_driver_Find_average_overhead;
+
+extern rtems_cpu_table Cpu_table;
+#define rtems_cpu_configuration_get_timer_average_overhead() \
+ (Cpu_table.timer_average_overhead)
+
+#define rtems_cpu_configuration_get_timer_least_valid() \
+ (Cpu_table.timer_least_valid)
+
+/*
+ * 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. */
+
+/*
+ m860.tbscr |= M860_TBSCR_TBIRQ(4) | M860_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 < rtems_cpu_configuration_get_timer_least_valid() ) {
+ return 0; /* below timer resolution */
+ }
+ return (total - rtems_cpu_configuration_get_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;
+}