1 files changed, 84 insertions, 0 deletions
diff --git a/src/chdelta.c b/src/chdelta.c
new file mode 100644
index 000000000..9a4f8b21d
--- /dev/null
+++ b/src/chdelta.c
@@ -0,0 +1,84 @@
+/*
+    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/>.
+*/
+
+/**
+ * @addtogroup VirtualTimers
+ * @{
+ */
+
+#include <ch.h>
+
+#ifdef CH_USE_VIRTUAL_TIMERS
+DeltaList dlist;
+
+/**
+ * Virtual Timers initialization. Internal use only.
+ */
+void chVTInit(void) {
+
+  dlist.dl_next = dlist.dl_prev = (VirtualTimer *)&dlist;
+  dlist.dl_dtime = MAXDELTA;
+}
+
+/**
+ * Enables a virtual timer.
+ * @param vtp the \p VirtualTimer structure pointer
+ * @param time the number of time ticks
+ * @param vtfunc the timer callback function. After invoking the callback
+ *               the timer is disabled and the structure can be disposed or
+ *               reused.
+ * @param par a parameter that will be passed to the callback function
+ * @note Must be called with the interrupts disabled.
+ * @note The associated function is invoked by an interrupt handler.
+ */
+void chVTSetI(VirtualTimer *vtp, t_time time, t_vtfunc vtfunc, void *par) {
+  VirtualTimer *p;
+
+  vtp->vt_func = vtfunc;
+  vtp->vt_par = par;
+  p = dlist.dl_next;
+  while (p->vt_dtime < time) {
+    time -= p->vt_dtime;
+    p = p->vt_next;
+  }
+
+  vtp->vt_prev = (vtp->vt_next = p)->vt_prev;
+  vtp->vt_prev->vt_next = p->vt_prev = vtp;
+  vtp->vt_dtime = time;
+  if (p != (VirtualTimer *)&dlist)
+    p->vt_dtime -= time;
+}
+
+/**
+ * Disables a Virtual Timer.
+ * @param vtp the \p VirtualTimer structure pointer
+ * @note It must be called with the interrupts disabled.
+ * @note The timer MUST be active when this function is invoked.
+ */
+void chVTResetI(VirtualTimer *vtp) {
+
+  if (vtp->vt_next != (VirtualTimer *)&dlist)
+    vtp->vt_next->vt_dtime += vtp->vt_dtime;
+  vtp->vt_prev->vt_next = vtp->vt_next;
+  vtp->vt_next->vt_prev = vtp->vt_prev;
+  vtp->vt_func = 0;
+}
+#endif /* CH_USE_VIRTUAL_TIMER */
+
+/** @} */