From ce92a90e58657ae14f291a75b00bd0391a9a89ff Mon Sep 17 00:00:00 2001
From: maralvira <maralvira>
Date: Mon, 17 Jan 2011 15:51:19 +0000
Subject: [PATCH] new timer setup routines.

---
 cpu/mc1322x/lib/tmr.c | 97 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 cpu/mc1322x/lib/tmr.c

diff --git a/cpu/mc1322x/lib/tmr.c b/cpu/mc1322x/lib/tmr.c
new file mode 100644
index 000000000..e2cc2afb6
--- /dev/null
+++ b/cpu/mc1322x/lib/tmr.c
@@ -0,0 +1,97 @@
+/*
+ * 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: tmr.c,v 1.1 2011/01/17 15:51:19 maralvira Exp $
+ */
+
+#include <mc1322x.h>
+#include <stdlib.h>
+#include "tmr.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)
+{
+	uint32_t actual_rate;
+	volatile struct TMR_struct *timer = TMR_ADDR(timer_num);
+	int log_divisor = 0;
+	uint32_t period;
+	
+	/* Turn timer off */
+	TMR0->ENBL &= ~(1 << timer_num);
+
+	/* Calculate optimal rate */
+	for (log_divisor = 0; log_divisor < 8; log_divisor++)
+	{
+		int denom = (rate * (1 << log_divisor));
+		period = (REF_OSC + denom/2) / denom;
+		if (period <= 65535)
+			break;
+	}
+	if (log_divisor >= 8)
+	{
+		period = 65535;
+		log_divisor = 7;
+	}
+
+	if (period < 2) period = 2;
+
+	actual_rate = REF_OSC / (period * (1 << log_divisor));
+
+	/* Set up timer */
+	
+	timer->LOAD = 0;
+	timer->CMPLD1 = (period - 1);
+	timer->COMP1 = timer->CMPLD1;
+	timer->CNTR = timer->LOAD;
+	timer->SCTRL = 0;
+	timer->CSCTRLbits = (struct TMR_CSCTRL) {
+		.CL1 = 0x01,	// Reload COMP1 when COMP1 matches
+	};
+	timer->CTRLbits = (struct TMR_CTRL) {
+		.COUNT_MODE = 1,		// Count rising edge of primary source
+		.PRIMARY_CNT_SOURCE = 8 + log_divisor,	// Peripheral clock divided by (divisor)
+		.LENGTH = 1,			// At compare, reset to LOAD
+	};
+
+	TMR0->ENBL |= (1 << timer_num);
+
+	if (enable_int) {
+		enable_irq(TMR);
+		timer->SCTRLbits.TCFIE = 1;
+	}
+
+	return actual_rate;
+}