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i2c_api.h
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2006-2015 ARM Limited 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http://www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 #ifndef MBED_I2C_API_H 00017 #define MBED_I2C_API_H 00018 00019 #include "device.h" 00020 #include "buffer.h" 00021 00022 #if DEVICE_I2C 00023 00024 /** 00025 * @defgroup I2CEvents I2C Events Macros 00026 * 00027 * @{ 00028 */ 00029 #define I2C_EVENT_ERROR (1 << 1) 00030 #define I2C_EVENT_ERROR_NO_SLAVE (1 << 2) 00031 #define I2C_EVENT_TRANSFER_COMPLETE (1 << 3) 00032 #define I2C_EVENT_TRANSFER_EARLY_NACK (1 << 4) 00033 #define I2C_EVENT_ALL (I2C_EVENT_ERROR | I2C_EVENT_TRANSFER_COMPLETE | I2C_EVENT_ERROR_NO_SLAVE | I2C_EVENT_TRANSFER_EARLY_NACK) 00034 00035 /**@}*/ 00036 00037 #if DEVICE_I2C_ASYNCH 00038 /** Asynch i2c hal structure 00039 */ 00040 typedef struct { 00041 struct i2c_s i2c; /**< Target specific i2c structure */ 00042 struct buffer_s tx_buff; /**< Tx buffer */ 00043 struct buffer_s rx_buff; /**< Rx buffer */ 00044 } i2c_t; 00045 00046 #else 00047 /** Non-asynch i2c hal structure 00048 */ 00049 typedef struct i2c_s i2c_t; 00050 00051 #endif 00052 00053 enum { 00054 I2C_ERROR_NO_SLAVE = -1, 00055 I2C_ERROR_BUS_BUSY = -2 00056 }; 00057 00058 #ifdef __cplusplus 00059 extern "C" { 00060 #endif 00061 00062 /** 00063 * \defgroup GeneralI2C I2C Configuration Functions 00064 * @{ 00065 */ 00066 00067 /** Initialize the I2C peripheral. It sets the default parameters for I2C 00068 * peripheral, and configure its specifieds pins. 00069 * @param obj The i2c object 00070 * @param sda The sda pin 00071 * @param scl The scl pin 00072 */ 00073 void i2c_init(i2c_t *obj, PinName sda, PinName scl); 00074 00075 /** Configure the I2C frequency. 00076 * @param obj The i2c object 00077 * @param hz Frequency in Hz 00078 */ 00079 void i2c_frequency(i2c_t *obj, int hz); 00080 00081 /** Send START command. 00082 * @param obj The i2c object 00083 */ 00084 int i2c_start(i2c_t *obj); 00085 00086 /** Send STOP command. 00087 * @param obj The i2c object 00088 */ 00089 int i2c_stop(i2c_t *obj); 00090 00091 /** Blocking reading data. 00092 * @param obj The i2c object 00093 * @param address 7-bit address (last bit is 1) 00094 * @param data The buffer for receiving 00095 * @param length Number of bytes to read 00096 * @param stop Stop to be generated after the transfer is done 00097 * @return Number of read bytes 00098 */ 00099 int i2c_read(i2c_t *obj, int address, char *data, int length, int stop); 00100 00101 /** Blocking sending data. 00102 * @param obj The i2c object 00103 * @param address 7-bit address (last bit is 0) 00104 * @param data The buffer for sending 00105 * @param length Number of bytes to wrte 00106 * @param stop Stop to be generated after the transfer is done 00107 * @return Number of written bytes 00108 */ 00109 int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop); 00110 00111 /** Reset I2C peripheral. TODO: The action here. Most of the implementation sends stop(). 00112 * @param obj The i2c object 00113 */ 00114 void i2c_reset(i2c_t *obj); 00115 00116 /** Read one byte. 00117 * @param obj The i2c object 00118 * @param last Acknoledge 00119 * @return The read byte 00120 */ 00121 int i2c_byte_read(i2c_t *obj, int last); 00122 00123 /** Write one byte. 00124 * @param obj The i2c object 00125 * @param data Byte to be written 00126 * @return 1 if NAK was received, 0 if ACK was received, 2 for timeout. 00127 */ 00128 int i2c_byte_write(i2c_t *obj, int data); 00129 00130 /**@}*/ 00131 00132 #if DEVICE_I2CSLAVE 00133 00134 /** 00135 * \defgroup SynchI2C Synchronous I2C Hardware Abstraction Layer for slave 00136 * @{ 00137 */ 00138 00139 /** Configure I2C as slave or master. 00140 * @param obj The I2C object 00141 * @return non-zero if a value is available 00142 */ 00143 void i2c_slave_mode(i2c_t *obj, int enable_slave); 00144 00145 /** Check to see if the I2C slave has been addressed. 00146 * @param obj The I2C object 00147 * @return The status - 1 - read addresses, 2 - write to all slaves, 00148 * 3 write addressed, 0 - the slave has not been addressed 00149 */ 00150 int i2c_slave_receive(i2c_t *obj); 00151 00152 /** Configure I2C as slave or master. 00153 * @param obj The I2C object 00154 * @return non-zero if a value is available 00155 */ 00156 int i2c_slave_read(i2c_t *obj, char *data, int length); 00157 00158 /** Configure I2C as slave or master. 00159 * @param obj The I2C object 00160 * @return non-zero if a value is available 00161 */ 00162 int i2c_slave_write(i2c_t *obj, const char *data, int length); 00163 00164 /** Configure I2C address. 00165 * @param obj The I2C object 00166 * @param idx Currently not used 00167 * @param address The address to be set 00168 * @param mask Currently not used 00169 */ 00170 void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask); 00171 00172 #endif 00173 00174 /**@}*/ 00175 00176 #if DEVICE_I2C_ASYNCH 00177 00178 /** 00179 * \defgroup AsynchI2C Asynchronous I2C Hardware Abstraction Layer 00180 * @{ 00181 */ 00182 00183 /** Start i2c asynchronous transfer. 00184 * @param obj The I2C object 00185 * @param tx The buffer to send 00186 * @param tx_length The number of words to transmit 00187 * @param rx The buffer to receive 00188 * @param rx_length The number of words to receive 00189 * @param address The address to be set - 7bit or 9 bit 00190 * @param stop If true, stop will be generated after the transfer is done 00191 * @param handler The I2C IRQ handler to be set 00192 * @param hint DMA hint usage 00193 */ 00194 void i2c_transfer_asynch(i2c_t *obj, const void *tx, size_t tx_length, void *rx, size_t rx_length, uint32_t address, uint32_t stop, uint32_t handler, uint32_t event, DMAUsage hint); 00195 00196 /** The asynchronous IRQ handler 00197 * @param obj The I2C object which holds the transfer information 00198 * @return event flags if a transfer termination condition was met or 0 otherwise. 00199 */ 00200 uint32_t i2c_irq_handler_asynch(i2c_t *obj); 00201 00202 /** Attempts to determine if I2C peripheral is already in use. 00203 * @param obj The I2C object 00204 * @return non-zero if the I2C module is active or zero if it is not 00205 */ 00206 uint8_t i2c_active(i2c_t *obj); 00207 00208 /** Abort ongoing asynchronous transaction. 00209 * @param obj The I2C object 00210 */ 00211 void i2c_abort_asynch(i2c_t *obj); 00212 00213 #endif 00214 00215 /**@}*/ 00216 00217 #ifdef __cplusplus 00218 } 00219 #endif 00220 00221 #endif 00222 00223 #endif
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