1 files changed, 102 insertions, 0 deletions
diff --git a/src/chvt.c b/src/chvt.c
new file mode 100644
index 000000000..77978e16c
--- /dev/null
+++ b/src/chvt.c
@@ -0,0 +1,102 @@
+/*
+    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>
+
+VTList vtlist;
+
+/**
+ * Virtual Timers initialization.
+ * @note Internal use only.
+ */
+void chVTInit(void) {
+
+  vtlist.vt_next = vtlist.vt_prev = (void *)&vtlist;
+  vtlist.vt_time = (systime_t)-1;
+  vtlist.vt_systime = 0;
+}
+
+/**
+ * Enables a virtual timer.
+ * @param vtp the \p VirtualTimer structure pointer
+ * @param time the number of time ticks, the value zero is allowed with
+ *             meaning "infinite". In this case the structure is initialized
+ *             but not inserted in the delta list, the timer will never be
+ *             triggered.
+ * @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, systime_t time, vtfunc_t vtfunc, void *par) {
+
+  vtp->vt_par = par;
+  vtp->vt_func = vtfunc;
+  if (time) {
+    VirtualTimer *p = vtlist.vt_next;
+    while (p->vt_time < time) {
+      time -= p->vt_time;
+      p = p->vt_next;
+    }
+
+    vtp->vt_prev = (vtp->vt_next = p)->vt_prev;
+    vtp->vt_prev->vt_next = p->vt_prev = vtp;
+    vtp->vt_time = time;
+    if (p != (void *)&vtlist)
+      p->vt_time -= time;
+  }
+  else
+    vtp->vt_next = vtp->vt_prev = vtp; // Allows a chVTResetI() on the fake timer.
+}
+
+/**
+ * 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 != (void *)&vtlist)
+    vtp->vt_next->vt_time += vtp->vt_time;
+  vtp->vt_prev->vt_next = vtp->vt_next;
+  vtp->vt_next->vt_prev = vtp->vt_prev;
+  vtp->vt_func = 0;
+}
+
+/**
+ * Checks if the current system time is within the specified time window.
+ * @param start the start of the time window (inclusive)
+ * @param end the end of the time window (non inclusive)
+ */
+bool_t chSysInTimeWindow(systime_t start, systime_t end) {
+
+  systime_t time = chSysGetTime();
+  return end >= start ? (time >= start) && (time < end) :
+                        (time >= start) || (time < end);
+}
+
+/** @} */