i2c.cpp

00001 /***************************************************************************//**
00002  *   @file   i2c.cpp
00003  *   @brief  Implementation of I2C Mbed platform driver interfaces
00004 ********************************************************************************
00005  * Copyright (c) 2019 - 2021 Analog Devices, Inc.
00006  * All rights reserved.
00007  *
00008  * This software is proprietary to Analog Devices, Inc. and its licensors.
00009  * By using this software you agree to the terms of the associated
00010  * Analog Devices Software License Agreement.
00011 *******************************************************************************/
00012 
00013 /******************************************************************************/
00014 /***************************** Include Files **********************************/
00015 /******************************************************************************/
00016 
00017 #include <stdio.h>
00018 #include <mbed.h>
00019 
00020 // Platform drivers needs to be C-compatible to work with other drivers
00021 #ifdef __cplusplus
00022 extern "C"
00023 {
00024 #endif //  _cplusplus
00025 
00026 #include "error.h"
00027 #include "i2c.h "
00028 #include "i2c_extra.h"
00029 
00030 /******************************************************************************/
00031 /********************** Macros and Constants Definitions **********************/
00032 /******************************************************************************/
00033 
00034 /******************************************************************************/
00035 /************************ Functions Declarations ******************************/
00036 /******************************************************************************/
00037 
00038 /******************************************************************************/
00039 /************************ Functions Definitions *******************************/
00040 /******************************************************************************/
00041 
00042 /**
00043  * @brief Initialize the I2C communication peripheral.
00044  * @param desc - The I2C descriptor.
00045  * @param param - The structure that contains the I2C parameters.
00046  * @return SUCCESS in case of success, FAILURE otherwise.
00047  */
00048 int32_t i2c_init_noos(struct i2c_desc **desc,
00049               const struct i2c_init_param *param)
00050 {
00051     mbed::I2C *i2c;     // pointer to new I2C instance
00052     mbed_i2c_desc *mbed_desc;   // pointer to mbed i2c desc
00053     i2c_desc *new_desc;
00054 
00055     if (desc) {
00056         // Create an i2c descriptor object for the device
00057         new_desc = (i2c_desc *)malloc(sizeof(i2c_desc));
00058         if (!new_desc) {
00059             goto err_new_desc;
00060         }
00061 
00062         // Address passed in parameter shifted left by 1 to form
00063         // 7-bit i2c slave address (7 MSBs) and the LSB acts as
00064         // r/w bit during i2c read/write operations
00065         new_desc->slave_address = ((param->slave_address) << 1);
00066 
00067         // Configure and instantiate I2C protocol
00068         i2c = new I2C(
00069             (PinName)(((mbed_i2c_init_param *)param->extra)->i2c_sda_pin),
00070             (PinName)(((mbed_i2c_init_param *)param->extra)->i2c_scl_pin));
00071 
00072         if (!i2c) {
00073             goto err_i2c;
00074         }
00075 
00076         // Create the i2c mbed descriptor object to store new i2c instance
00077         mbed_desc = (mbed_i2c_desc *)malloc(sizeof(mbed_i2c_desc));
00078         if (!mbed_desc) {
00079             goto err_mbed_desc;
00080         }
00081 
00082         mbed_desc->i2c_port = (I2C *)i2c;
00083         new_desc->extra = (mbed_i2c_desc *)mbed_desc;
00084 
00085         *desc = new_desc;
00086 
00087         return SUCCESS;
00088     }
00089 
00090 err_mbed_desc:
00091     free(i2c);
00092 err_i2c:
00093     free(new_desc);
00094 err_new_desc:
00095     // Nothing to free
00096 
00097     return FAILURE;
00098 }
00099 
00100 
00101 /**
00102  * @brief Free the resources allocated by i2c_init_noos().
00103  * @param desc - The I2C descriptor.
00104  * @return SUCCESS in case of success, FAILURE otherwise.
00105  */
00106 int32_t i2c_remove(struct i2c_desc *desc)
00107 {
00108     if (desc) {
00109         // Free the I2C port object
00110         if ((I2C *)(((mbed_i2c_desc *)(desc->extra))->i2c_port)) {
00111             delete((I2C *)(((mbed_i2c_desc *)(desc->extra))->i2c_port));
00112         }
00113 
00114         // Free the I2C extra descriptor object
00115         if ((mbed_i2c_desc *)(desc->extra)) {
00116             free((mbed_i2c_desc *)(desc->extra));
00117         }
00118 
00119         // Free the I2C descriptor object
00120         free(desc);
00121 
00122         return SUCCESS;
00123     }
00124 
00125     return FAILURE;
00126 }
00127 
00128 
00129 /**
00130  * @brief Write data to a slave device.
00131  * @param desc - The I2C descriptor.
00132  * @param data - Buffer that stores the transmission data.
00133  * @param bytes_number - Number of bytes to write.
00134  * @param stop_bit - Stop condition control.
00135  *                   Example: 0 - A stop condition will not be generated;
00136  *                            1 - A stop condition will be generated.
00137  * @return SUCCESS in case of success, FAILURE otherwise.
00138  */
00139 
00140 int32_t i2c_write_noos(struct i2c_desc *desc,
00141                uint8_t *data,
00142                uint8_t bytes_number,
00143                uint8_t stop_bit)
00144 {
00145     mbed::I2C *i2c;
00146     i2c = (I2C *)(((mbed_i2c_desc *)(desc->extra))->i2c_port);
00147 
00148     /**
00149         The MBED I2C API is reversed for parameter 4
00150         Instead of stop_bit - it has
00151         @param repeated   - Repeated start, true - don't send stop at end default value is false.
00152         Inverting here to keep the no-OS/platform_drivers API
00153      */
00154     if (!(i2c->write(desc->slave_address, (char *)data, bytes_number, !stop_bit))) {
00155         return SUCCESS;
00156     } else {
00157         return FAILURE;
00158     }
00159 }
00160 
00161 
00162 /**
00163  * @brief Read data from a slave device.
00164  * @param desc - The I2C descriptor.
00165  * @param data - Buffer that will store the received data.
00166  * @param bytes_number - Number of bytes to read.
00167  * @param stop_bit - Stop condition control.
00168  *                   Example: 0 - A stop condition will not be generated;
00169  *                            1 - A stop condition will be generated.
00170  * @return SUCCESS in case of success, FAILURE otherwise.
00171  */
00172 int32_t i2c_read_noos(struct i2c_desc *desc,
00173               uint8_t *data,
00174               uint8_t bytes_number,
00175               uint8_t stop_bit)
00176 {
00177     mbed::I2C *i2c;
00178     i2c = (I2C *)(((mbed_i2c_desc *)(desc->extra))->i2c_port);
00179 
00180     /**
00181         The MBED I2C API is reversed for parameter 4
00182         Instead of stop_bit - it has
00183         @param repeated   - Repeated start, true - don't send stop at end default value is false.
00184         Inverting here to keep the no-OS/platform_drivers API
00185      */
00186     if (!(i2c->read(desc->slave_address, (char *)data, bytes_number, !stop_bit))) {
00187         return SUCCESS;
00188     } else {
00189         return FAILURE;
00190     }
00191 }
00192 
00193 #ifdef __cplusplus
00194 }
00195 #endif //  _cplusplus