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 /** 28 * @file 29 * @brief Inter-Integrated Circuit 30 * 31 * An i2c context represents a master on an i2c bus and that context can 32 * communicate to multiple i2c slaves by configuring the address. 33 * @htmlinclude i2c.txt 34 * 35 * @snippet i2c_HMC5883L.c Interesting 36 */ 37 38 #ifdef __cplusplus 39 extern "C" { 40 #endif 41 42 #include <stdlib.h> 43 #include <stdio.h> 44 #include <fcntl.h> 45 #include <stdint.h> 46 47 #include "common.h" 48 #include "gpio.h" 49 50 /** 51 * Opaque pointer definition to the internal struct _i2c 52 */ 53 typedef struct _i2c* mraa_i2c_context; 54 55 /** 56 * Initialise i2c context, using board defintions 57 * 58 * @param bus i2c bus to use 59 * @return i2c context or NULL 60 */ 61 mraa_i2c_context mraa_i2c_init(int bus); 62 63 /** 64 * Initialise i2c context, passing in the i2c bus to use. 65 * 66 * @param bus The i2c bus to use i.e. /dev/i2c-2 would be "2" 67 * @return i2c context or NULL 68 */ 69 mraa_i2c_context mraa_i2c_init_raw(unsigned int bus); 70 71 /** 72 * Sets the frequency of the i2c context. Most platforms do not support this. 73 * 74 * @param dev The i2c context 75 * @param mode The bus mode 76 * @return Result of operation 77 */ 78 mraa_result_t mraa_i2c_frequency(mraa_i2c_context dev, mraa_i2c_mode_t mode); 79 80 /** 81 * Simple bulk read from an i2c context, this will always begin with the i2c 82 * offset 0x0 83 * 84 * @param dev The i2c context 85 * @param data pointer to the byte array to read data in to 86 * @param length max number of bytes to read 87 * @return length of the read in bytes or 0 88 */ 89 int mraa_i2c_read(mraa_i2c_context dev, uint8_t* data, int length); 90 91 /** 92 * Simple read for a single byte from the i2c context, this will always begin 93 * with the i2c offset 0x0 94 * 95 * @param dev The i2c context 96 * @return The result of the read and 0 if failed 97 */ 98 uint8_t mraa_i2c_read_byte(mraa_i2c_context dev); 99 100 /** 101 * Read a single byte from i2c context, from designated register 102 * 103 * @param dev The i2c context 104 * @param command The register 105 * @return The result of the read and 0 if failed 106 */ 107 uint8_t mraa_i2c_read_byte_data(mraa_i2c_context dev, const uint8_t command); 108 109 /** 110 * Read a single word from i2c context, from designated register 111 * 112 * @param dev The i2c context 113 * @param command The register 114 * @return The result of the read and 0 if failed 115 */ 116 uint16_t mraa_i2c_read_word_data(mraa_i2c_context dev, const uint8_t command); 117 118 /** 119 * Bulk read from i2c context, starting from designated register 120 * 121 * @param dev The i2c context 122 * @param command The register 123 * @param data pointer to the byte array to read data in to 124 * @param length max number of bytes to read 125 * @return The length in bytes passed to the function or -1 126 */ 127 int mraa_i2c_read_bytes_data(mraa_i2c_context dev, uint8_t command, uint8_t* data, int length); 128 129 /** 130 * Write length bytes to the bus, the first byte in the array is the 131 * command/register to write 132 * 133 * @param dev The i2c context 134 * @param data pointer to the byte array to be written 135 * @param length the number of bytes to transmit 136 * @return Result of operation 137 */ 138 mraa_result_t mraa_i2c_write(mraa_i2c_context dev, const uint8_t* data, int length); 139 140 /** 141 * Write a single byte to an i2c context, always at offset 0x0 142 * 143 * @param dev The i2c context 144 * @param data The byte to write 145 * @return Result of operation 146 */ 147 mraa_result_t mraa_i2c_write_byte(mraa_i2c_context dev, const uint8_t data); 148 149 /** 150 * Write a single byte to an i2c context 151 * 152 * @param dev The i2c context 153 * @param data The byte to write 154 * @param command The register 155 * @return Result of operation 156 */ 157 mraa_result_t mraa_i2c_write_byte_data(mraa_i2c_context dev, const uint8_t data, const uint8_t command); 158 159 /** 160 * Write a single word to an i2c context 161 * 162 * @param dev The i2c context 163 * @param data The word to write 164 * @param command The register 165 * @return Result of operation 166 */ 167 mraa_result_t mraa_i2c_write_word_data(mraa_i2c_context dev, const uint16_t data, const uint8_t command); 168 169 /** 170 * Sets the i2c context address. 171 * 172 * @param dev The i2c context 173 * @param address The address to set for the slave (ignoring the least 174 * signifcant bit). If set to 0, the slave will only respond to the 175 * general call address. 176 * @return Result of operation 177 */ 178 mraa_result_t mraa_i2c_address(mraa_i2c_context dev, uint8_t address); 179 180 /** 181 * De-inits an mraa_i2c_context device 182 * 183 * @param dev The i2c context 184 * @return Result of operation 185 */ 186 mraa_result_t mraa_i2c_stop(mraa_i2c_context dev); 187 188 #ifdef __cplusplus 189 } 190 #endif 191
