added experimental avr rtimer-arch implementation

8 seconds wraparound
2007-11-29 02:44:05 +00:00 · 2007-11-29 02:44:05 +00:00 · 3a0ba03407
commit 3a0ba03407
parent d2140381d5
3 changed files with 147 additions and 3 deletions
--- a/cpu/avr/rtimer-arch.c
+++ b/cpu/avr/rtimer-arch.c
@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2007, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ * $Id: rtimer-arch.c,v 1.1 2007/11/29 02:44:05 fros4943 Exp $
+ */
+
+/**
+ * \file
+ *         AVR-specific rtimer code
+ * \author
+ *         Fredrik Osterlind <fros@sics.se>
+ */
+
+/* OBS: 8 seconds maximum time! */
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+#include "lib/energest.h"
+#include "sys/rtimer.h"
+#include "rtimer-arch.h"
+
+/*---------------------------------------------------------------------------*/
+SIGNAL (SIG_OUTPUT_COMPARE3A) {
+  ENERGEST_ON(ENERGEST_TYPE_IRQ);
+
+  ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
+      (1 << TICIE3) | (1 << OCIE3C));
+
+  /* Call rtimer callback */
+  rtimer_run_next();
+
+  ENERGEST_OFF(ENERGEST_TYPE_IRQ);
+}
+/*---------------------------------------------------------------------------*/
+void
+rtimer_arch_init(void)
+{
+  /* Disable interrupts (store old state) */
+  uint8_t sreg;
+  sreg = SREG;
+  cli ();
+
+  ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
+      (1 << TICIE3) | (1 << OCIE3C));
+  ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
+  (1 << OCF3C); 
+
+  /* Default timer behaviour */
+  TCCR3A = 0;
+  TCCR3B = 0;
+  TCCR3C = 0;
+
+  /* Reset counter */
+  TCNT3 = 0;
+
+  /* Maximum prescaler */
+  TCCR3B |= 5;
+
+  /* Restore interrupt state */
+  SREG = sreg;
+}
+/*---------------------------------------------------------------------------*/
+void
+rtimer_arch_schedule(rtimer_clock_t t)
+{
+  /* Disable interrupts (store old state) */
+  uint8_t sreg;
+  sreg = SREG;
+  cli ();
+
+  /* Set compare register */
+  OCR3A = t;
+  ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
+  (1 << OCF3C);
+  ETIMSK |= (1 << OCIE3A);
+
+  /* Restore interrupt state */
+  SREG = sreg;
+}