1 files changed, 68 insertions, 0 deletions
diff --git a/src/lib/evtimer.c b/src/lib/evtimer.c
new file mode 100644
index 000000000..212c8f124
--- /dev/null
+++ b/src/lib/evtimer.c
@@ -0,0 +1,68 @@
+/*
+    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
+
+    This file is part of ChibiOS/RT.
+
+    ChibiOS/RT is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    ChibiOS/RT is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file evtimer.c
+ * @{
+ * Event Timer, this timer generates an event at regular intervals. The
+ * listening threads can use the event to perform time related activities.
+ * Multiple threads can listen to the same timer.
+ */
+
+#include <ch.h>
+
+#include "evtimer.h"
+
+static void tmrcb(void *p) {
+  EvTimer *etp = p;
+
+  chVTSetI(&etp->et_vt, etp->et_interval, tmrcb, etp);
+}
+
+/**
+ * Starts the timer, if the timer was already running then the function has
+ * no effect.
+ * @param etp pointer to an initialized \p EvTimer structure.
+ */
+void evtStart(EvTimer *etp) {
+
+  chSysLock();
+
+  if (!etp->et_vt.vt_func)
+    chVTSetI(&etp->et_vt, etp->et_interval, tmrcb, etp);
+
+  chSysUnlock();
+}
+
+/**
+ * Stops the timer, if the timer was already stopped then the function has
+ * no effect.
+ * @param etp pointer to an initialized \p EvTimer structure.
+ */
+void evtStop(EvTimer *etp) {
+
+  chSysLock();
+
+  if (etp->et_vt.vt_func)
+    chVTResetI(&etp->et_vt);
+
+  chSysUnlock();
+}
+
+/** @} */