initial cleanup and mapping

devLib/ds1302.c

@@ -0,0 +1,240 @@
+/*
+ * ds1302.c:
+ *	Real Time clock
+ *
+ * Copyright (c) 2013 Gordon Henderson.
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ *    wiringPi is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    wiringPi 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 Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public License
+ *    along with wiringPi.  If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdarg.h>
+
+#include <wiringPi.h>
+
+#include "ds1302.h"
+
+// Register defines
+
+#define	RTC_SECS	 0
+#define	RTC_MINS	 1
+#define	RTC_HOURS	 2
+#define	RTC_DATE	 3
+#define	RTC_MONTH	 4
+#define	RTC_DAY		 5
+#define	RTC_YEAR	 6
+#define	RTC_WP		 7
+#define	RTC_TC		 8
+#define	RTC_BM		31
+
+
+// Locals
+
+static int dPin, cPin, sPin ;
+
+/*
+ * dsShiftIn:
+ *	Shift a number in from the chip, LSB first. Note that the data is
+ *	sampled on the trailing edge of the last clock, so it's valid immediately.
+ *********************************************************************************
+ */
+
+static unsigned int dsShiftIn (void)
+{
+  uint8_t value = 0 ;
+  int i ;
+
+  pinMode (dPin, INPUT) ;	delayMicroseconds (1) ;
+
+  for (i = 0 ; i < 8 ; ++i)
+  {
+    value |= (digitalRead (dPin) << i) ;
+    digitalWrite (cPin, HIGH) ; delayMicroseconds (1) ;
+    digitalWrite (cPin, LOW) ;	delayMicroseconds (1) ;
+  }
+
+  return value;
+}
+
+
+/*
+ * dsShiftOut:
+ *	A normal LSB-first shift-out, just slowed down a bit - the Pi is
+ *	a bit faster than the chip can handle.
+ *********************************************************************************
+ */
+
+static void dsShiftOut (unsigned int data)
+{
+  int i ;
+
+  pinMode (dPin, OUTPUT) ;
+
+  for (i = 0 ; i < 8 ; ++i)
+  {
+    digitalWrite (dPin, data & (1 << i)) ;	delayMicroseconds (1) ;
+    digitalWrite (cPin, HIGH) ;			delayMicroseconds (1) ;
+    digitalWrite (cPin, LOW) ;			delayMicroseconds (1) ;
+  }
+}
+
+
+/*
+ * ds1302regRead: ds1302regWrite:
+ *	Read/Write a value to an RTC Register or RAM location on the chip
+ *********************************************************************************
+ */
+
+static unsigned int ds1302regRead (const int reg)
+{
+  unsigned int data ;
+
+  digitalWrite (sPin, HIGH) ; delayMicroseconds (1) ;
+    dsShiftOut (reg) ;
+    data = dsShiftIn () ;
+  digitalWrite (sPin, LOW)  ; delayMicroseconds (1) ;
+
+  return data ;
+}
+
+static void ds1302regWrite (const int reg, const unsigned int data)
+{
+  digitalWrite (sPin, HIGH) ; delayMicroseconds (1) ;
+    dsShiftOut (reg) ;
+    dsShiftOut (data) ;
+  digitalWrite (sPin, LOW)  ; delayMicroseconds (1) ;
+}
+
+
+/*
+ * ds1302rtcWrite: ds1302rtcRead:
+ *	Writes/Reads the data to/from the RTC register
+ *********************************************************************************
+ */
+
+unsigned int ds1302rtcRead (const int reg)
+{
+  return ds1302regRead (0x81 | ((reg & 0x1F) << 1)) ;
+}
+
+void ds1302rtcWrite (int reg, unsigned int data)
+{
+  ds1302regWrite (0x80 | ((reg & 0x1F) << 1), data) ;
+}
+
+
+/*
+ * ds1302ramWrite: ds1302ramRead:
+ *	Writes/Reads the data to/from the RTC register
+ *********************************************************************************
+ */
+
+unsigned int ds1302ramRead (const int addr)
+{
+  return ds1302regRead (0xC1 | ((addr & 0x1F) << 1)) ;
+}
+
+void ds1302ramWrite (const int addr, const unsigned int data)
+{
+  ds1302regWrite ( 0xC0 | ((addr & 0x1F) << 1), data) ;
+}
+
+/*
+ * ds1302clockRead:
+ *	Read all 8 bytes of the clock in a single operation
+ *********************************************************************************
+ */
+
+void ds1302clockRead (int clockData [8])
+{
+  int i ;
+  unsigned int regVal = 0x81 | ((RTC_BM & 0x1F) << 1) ;
+
+  digitalWrite (sPin, HIGH) ; delayMicroseconds (1) ;
+
+  dsShiftOut (regVal) ;
+  for (i = 0 ; i < 8 ; ++i)
+    clockData [i] = dsShiftIn () ;
+
+  digitalWrite (sPin, LOW) ;  delayMicroseconds (1) ;
+}
+
+
+/*
+ * ds1302clockWrite:
+ *	Write all 8 bytes of the clock in a single operation
+ *********************************************************************************
+ */
+
+void ds1302clockWrite (const int clockData [8])
+{
+  int i ;
+  unsigned int regVal = 0x80 | ((RTC_BM & 0x1F) << 1) ;
+
+  digitalWrite (sPin, HIGH) ; delayMicroseconds (1) ;
+
+  dsShiftOut (regVal) ;
+  for (i = 0 ; i < 8 ; ++i)
+    dsShiftOut (clockData [i]) ;
+
+  digitalWrite (sPin, LOW) ;  delayMicroseconds (1) ;
+}
+
+
+/*
+ * ds1302trickleCharge:
+ *	Set the bits on the trickle charger.
+ *	Probably best left alone...
+ *********************************************************************************
+ */
+
+void ds1302trickleCharge (const int diodes, const int resistors)
+{
+  if (diodes + resistors == 0)
+    ds1302rtcWrite (RTC_TC, 0x5C) ;	// Disabled
+  else
+    ds1302rtcWrite (RTC_TC, 0xA0 | ((diodes & 3) << 2) | (resistors & 3)) ;
+}
+
+
+
+
+/*
+ * ds1302setup:
+ *	Initialise the chip & remember the pins we're using
+ *********************************************************************************
+ */
+
+void ds1302setup (const int clockPin, const int dataPin, const int csPin)
+{
+  dPin = dataPin ;
+  cPin = clockPin ;
+  sPin = csPin ;
+
+  digitalWrite (dPin, LOW) ;
+  digitalWrite (cPin, LOW) ;
+  digitalWrite (sPin, LOW) ;
+
+  pinMode (dPin, OUTPUT) ;
+  pinMode (cPin, OUTPUT) ;
+  pinMode (sPin, OUTPUT) ;
+
+  ds1302rtcWrite (RTC_WP, 0) ;	// Remove write-protect
+}