ds1307: initial implementation of the ds1307 RTC

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Sarah Knepper <sarah.knepper@intel.com>

src/ds1307/ds1307.h

@@ -0,0 +1,186 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * Adapted from Seeed Studio library:
+ * https://github.com/Seeed-Studio/RTC_DS1307
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#pragma once
+
+#include <string>
+#include <mraa/i2c.h>
+
+#define DS1307_I2C_BUS     0
+#define DS1307_I2C_ADDR    0x68
+
+// Days of the week
+#define DS1307_DAY_MON 1
+#define DS1307_DAY_TUE 2
+#define DS1307_DAY_WED 3
+#define DS1307_DAY_THU 4
+#define DS1307_DAY_FRI 5
+#define DS1307_DAY_SAT 6
+#define DS1307_DAY_SUN 7
+
+namespace upm {
+
+  /**
+   * @brief C++ API for the DS1307 Real Time CLock
+   *
+   * UPM module for the DS1307 based RTC.  The clock can provide information
+   * about the seconds, minutes, hours, day of the week, day of the month,
+   * month, and year.  It can operate in either 24-hour or 12-hour format.
+   *
+   * This device can also output a square wave at 1Khz, 4Khz, 8Khz, and 32Khz.  
+   * However, this capability is not implemented in this module.
+   *
+   * @ingroup i2c ds1307 RTC
+   * @snippet ds1307.cxx Interesting
+   */
+  class DS1307 {
+  public:
+    /**
+     * ds1307 Real Time Clock constructor
+     *
+     * @param bus i2c bus to use
+     */
+    DS1307(int bus);
+
+    /**
+     * DS1307 Destructor
+     */
+    ~DS1307();
+
+    /**
+     * Load all of the time values
+     *
+     * @return True if time data loaded successfully
+     */
+    bool loadTime();
+
+    /**
+     * Set the time.  You should call loadTime() beforehand to
+     * maintain consistency
+     *
+     * @return True if time saved successfully
+     */
+    bool setTime();
+
+    /**
+     * Enable the oscillator on the clock.  
+     *
+     * @return 0 (MRAA_SUCCESS) if successful; non-zero otherwise
+     */
+    mraa_result_t enableClock();
+
+    /**
+     * Disable the oscillator on the clock.  This will prevent the clock
+     * from updating any time/date values
+     *
+     * @return 0 (MRAA_SUCCESS) if successful; non-zero otherwise
+     */
+    mraa_result_t disableClock();
+
+    /**
+     * Write value(s) into registers
+     *
+     * @param reg register location to start writing into
+     * @param buffer buffer for data storage
+     * @param len number of bytes to write
+     * @return 0 (MRAA_SUCCESS) if successful; non-zero otherwise
+     */
+    mraa_result_t writeBytes(uint8_t reg, uint8_t *buffer, unsigned int len);
+
+    /**
+     * Read value(s) from registers
+     *
+     * @param reg register location to start reading from
+     * @param buffer buffer for data storage
+     * @param len number of bytes to read
+     * @return number of bytes read
+     */
+    uint8_t readBytes(uint8_t reg, uint8_t *buffer, unsigned int len);
+
+    /**
+     * Convert a BCD value into decimal
+     *
+     * @param val BCD value to convert
+     * @return the converted value in decimal
+     */
+    unsigned int bcdToDec(uint8_t val);
+
+    /**
+     * Convert a decimal value into BCD
+     *
+     * @param val decimal value to convert
+     * @return the converted value in BCD
+     */
+    uint8_t decToBcd(unsigned int val);
+
+    // These variables store the time data loaded with loadTime(), and
+    // will be the source of data when setTime() is called.  It is a
+    // good idea call loadTime() to setup the current values before
+    // calling setTime() to ensure RTC data is consistent
+
+    /**
+     * holds the seconds
+     */
+    unsigned int seconds;
+    /**
+     * holds the minutes
+     */
+    unsigned int minutes;
+    /**
+     * holds the hours, 1-12 in am/pm mode, 0-23 otherwise
+     */
+    unsigned int hours;
+    /**
+     * holds the day of the week, 1-7 where 1 is Sunday
+     */
+    unsigned int dayOfWeek;
+    /**
+     * holds the day of the month, 1-31
+     */
+    unsigned int dayOfMonth;
+    /**
+     * holds the month, 1-12
+     */
+    unsigned int month;
+    /**
+     * holds the year, 0-99
+     */
+    unsigned int year;
+    /**
+     * True if in AM/PM mode, false if 24h format.
+     */
+    bool amPmMode;
+    /**
+     * If in AmPmMode (12-hr), then this is true if it's PM, clear if AM
+     */
+    bool pm;
+
+  private:
+    mraa_i2c_context m_i2c;
+  };
+}
+
+