1 /*
2  * Author: Yevgeniy Kiveisha <yevgeniy.kiveisha@intel.com>
3  * Copyright (c) 2014 Intel Corporation.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be
14  * included in all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23  */
24 
25 #include <iostream>
26 #include <unistd.h>
27 #include <stdlib.h>
28 #include <stdexcept>
29 
30 #include "maxds3231m.h"
31 
32 using namespace upm;
33 
MAXDS3231M(int bus,int devAddr)34 MAXDS3231M::MAXDS3231M (int bus, int devAddr) : m_i2Ctx(bus) {
35     m_name = "MAXDS3231M";
36 
37     m_i2cAddr = devAddr;
38     m_bus = bus;
39 
40     mraa::Result ret = m_i2Ctx.address(m_i2cAddr);
41     if (ret != mraa::SUCCESS) {
42         throw std::invalid_argument(std::string(__FUNCTION__) +
43                                     ": m_i2Ctx.address() failed");
44     }
45 }
46 
47 void
setDate(Time3231 & time)48 MAXDS3231M::setDate (Time3231 &time) {
49     uint8_t *data = (uint8_t *)&time;
50 
51     i2cWriteReg_N (TIME_CAL_ADDR, 7, data);
52 }
53 
54 bool
getDate(Time3231 & time)55 MAXDS3231M::getDate (Time3231 &time) {
56     uint8_t buffer[7];
57 
58     // We need 7 bytes of data.
59     if (i2cReadReg_N (TIME_CAL_ADDR, 7, buffer) > 6) {
60         uint8_t century = (buffer[5] & 0x80) >> 7;
61 
62         time.second     = BCDtoDEC(buffer[0]);
63         time.minute     = BCDtoDEC(buffer[1]);
64         time.hour       = BCDtoDEC(buffer[2]);
65         time.day        = BCDtoDEC(buffer[4]);
66         time.month      = BCDtoDEC(buffer[5] & 0x1F);
67         time.year       = (century == 1) ? 2000 + BCDtoDEC(buffer[6]) : 1900 + BCDtoDEC(buffer[6]);
68         time.weekDay    = BCDtoDEC(buffer[3]);
69 
70         return true;
71     }
72 
73     return false;
74 }
75 
76 uint16_t
getTemperature()77 MAXDS3231M::getTemperature () {
78     uint8_t     buffer[2];
79     uint8_t     msb     = 0;
80     uint8_t     lsb     = 0;
81 
82     i2cReadReg_N (TEMPERATURE_ADDR, 2, buffer);
83     msb = buffer[0];
84     lsb = buffer[1] >> 6;
85 
86     if ((msb & 0x80) != 0)
87         msb |= ~((1 << 8) - 1); // if negative get two's complement
88 
89     return 0.25 * lsb + msb;
90 }
91 
92 /*
93  * **************
94  *  private area
95  * **************
96  */
97 uint16_t
i2cReadReg_N(int reg,unsigned int len,uint8_t * buffer)98 MAXDS3231M::i2cReadReg_N (int reg, unsigned int len, uint8_t * buffer) {
99     int readByte = 0;
100 
101     m_i2Ctx.address(m_i2cAddr);
102     m_i2Ctx.writeByte(reg);
103 
104     m_i2Ctx.address(m_i2cAddr);
105     readByte = m_i2Ctx.read(buffer, len);
106     return readByte;
107 }
108 
109 mraa::Result
i2cWriteReg_N(uint8_t reg,unsigned int len,uint8_t * buffer)110 MAXDS3231M::i2cWriteReg_N (uint8_t reg, unsigned int len, uint8_t * buffer) {
111     mraa::Result error = mraa::SUCCESS;
112 
113     error = m_i2Ctx.address (m_i2cAddr);
114     error = m_i2Ctx.write (buffer, len);
115 
116     return error;
117 }
118 
119 uint8_t
DECtoBSD(uint8_t data)120 MAXDS3231M::DECtoBSD(uint8_t data) {
121     return ((data / 10 * 16) + (data % 10));
122 }
123 
124 uint8_t
BCDtoDEC(uint8_t data)125 MAXDS3231M::BCDtoDEC(uint8_t data) {
126     return ((data / 16 * 10) + (data % 16));
127 }
128