1 /* 2 * Author: Brendan Le Foll <brendan.le.foll (at) 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 31 namespace 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 */ 43 class 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
