add timer setup routines

lib/include/timer.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
+ * to the MC1322x project (http://mc1322x.devl.org)
+ * 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 libmc1322x: see http://mc1322x.devl.org
+ * for details. 
+ *
+ * $Id$
+ */
+
+#ifndef TIMER_H
+#define TIMER_H
+
+/* Initialize timer.  This just counts and interrupts, doesn't drive an output.
+   timer_num = 0, 1, 2, 3
+   rate = desired rate in Hz,
+   enable_int = whether to enable an interrupt on every cycle
+   Returns actual timer rate. */
+uint32_t timer_setup_ex(int timer_num, uint32_t rate, int enable_int);
+
+/* Initialize timer.  This just counts and interrupts, doesn't drive an output.
+   timer = TMR0, TMR1, TMR2, TMR3
+   rate = desired rate in Hz,
+   enable_int = whether to enable an interrupt on every cycle
+   Returns actual timer rate. */
+#define timer_setup(timer,rate,enable_int) timer_setup_ex(TMR_NUM(timer), rate, enable_int)
+
+#endif