1/*
2 * Author: Brendan Le Foll <brendan.le.foll@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#pragma once
26
27#include "i2c.h"
28#include "types.hpp"
29#include <stdexcept>
30
31namespace mraa
32{
33
34/**
35 * @brief API to Inter-Integrated Circuit
36 *
37 * An I2c object represents an i2c master and can talk multiple i2c slaves by
38 * selecting the correct address
39 * @htmlinclude i2c.txt
40 *
41 * @snippet I2c-compass.cpp Interesting
42 */
43class I2c
44{
45  public:
46    /**
47     * Instantiates an i2c bus. Multiple instances of the same bus can
48     * exist and the bus is not guarranteed to be on the correct address
49     * before read/write.
50     *
51     * @param bus The i2c bus to use
52     * @param raw Whether to disable pinmapper for your board
53     */
54    I2c(int bus, bool raw = false)
55    {
56        if (raw) {
57            m_i2c = mraa_i2c_init_raw(bus);
58        } else {
59            m_i2c = mraa_i2c_init(bus);
60        }
61        if (m_i2c == NULL) {
62            throw std::invalid_argument("Invalid i2c bus");
63        }
64    }
65
66    /**
67     * Closes the I2c Bus used. This does not guarrantee the bus will not
68     * be usable by anyone else or communicates this disconnect to any
69     * slaves.
70     */
71    ~I2c()
72    {
73        mraa_i2c_stop(m_i2c);
74    }
75
76    /**
77     * Sets the i2c Frequency for communication. Your board may not support
78     * the set frequency. Anyone can change this at any time and this will
79     * affect every slave on the bus
80     *
81     * @param mode Frequency to set the bus to
82     * @return Result of operation
83     */
84    Result
85    frequency(I2cMode mode)
86    {
87        return (Result) mraa_i2c_frequency(m_i2c, (mraa_i2c_mode_t) mode);
88    }
89
90    /**
91     * Set the slave to talk to, typically called before every read/write
92     * operation
93     *
94     * @param address Communicate to the i2c slave on this address
95     * @return Result of operation
96     */
97    Result
98    address(uint8_t address)
99    {
100        return (Result) mraa_i2c_address(m_i2c, address);
101    }
102
103    /**
104     * Read exactly one byte from the bus
105     *
106     * @return char read from the bus
107     */
108    uint8_t
109    readByte()
110    {
111        return (uint8_t) mraa_i2c_read_byte(m_i2c);
112    }
113
114    /**
115     * Read length bytes from the bus into *data pointer
116     *
117     * @param data Data to read into
118     * @param length Size of read in bytes to make
119     * @return length of read, should match length
120     */
121    int
122    read(uint8_t* data, int length)
123    {
124        return mraa_i2c_read(m_i2c, data, length);
125    }
126
127    /**
128     * Read byte from an i2c register
129     *
130     * @param reg Register to read from
131     * @return char read from register
132     */
133    uint8_t
134    readReg(uint8_t reg)
135    {
136        return mraa_i2c_read_byte_data(m_i2c, reg);
137    }
138
139    /**
140     * Read word from an i2c register
141     *
142     * @param reg Register to read from
143     * @return char read from register
144     */
145    uint16_t
146    readWordReg(uint8_t reg)
147    {
148        return mraa_i2c_read_word_data(m_i2c, reg);
149    }
150
151    /**
152     * Read length bytes from the bus into *data pointer starting from
153     * an i2c register
154     *
155     * @param reg Register to read from
156     * @param data pointer to the byte array to read data in to
157     * @param length max number of bytes to read
158     * @return length passed to the function or -1
159     */
160    int
161    readBytesReg(uint8_t reg, uint8_t* data, int length)
162    {
163        return mraa_i2c_read_bytes_data(m_i2c, reg, data, length);
164    }
165
166    /**
167     * Write a byte on the bus
168     *
169     * @param data The byte to send on the bus
170     * @return Result of operation
171     */
172    Result
173    writeByte(uint8_t data)
174    {
175        return (Result) mraa_i2c_write_byte(m_i2c, data);
176    }
177
178    /**
179     * Write length bytes to the bus, the first byte in the array is the
180     * command/register to write
181     *
182     * @param data Buffer to send on the bus, first byte is i2c command
183     * @param length Size of buffer to send
184     * @return Result of operation
185     */
186    Result
187    write(const uint8_t* data, int length)
188    {
189        return (Result) mraa_i2c_write(m_i2c, data, length);
190    }
191
192    /**
193     * Write a byte to an i2c register
194     *
195     * @param reg Register to write to
196     * @param data Value to write to register
197     * @return Result of operation
198     */
199    Result
200    writeReg(uint8_t reg, uint8_t data)
201    {
202        return (Result) mraa_i2c_write_byte_data(m_i2c, data, reg);
203    }
204
205    /**
206     * Write a word to an i2c register
207     *
208     * @param reg Register to write to
209     * @param data Value to write to register
210     * @return Result of operation
211     */
212    Result
213    writeWordReg(uint8_t reg, uint16_t data)
214    {
215        return (Result) mraa_i2c_write_word_data(m_i2c, data, reg);
216    }
217
218  private:
219    mraa_i2c_context m_i2c;
220};
221}
222