i2c_api.h

00001 
00002 /** \addtogroup hal */
00003 /** @{*/
00004 /* mbed Microcontroller Library
00005  * Copyright (c) 2006-2015 ARM Limited
00006  * SPDX-License-Identifier: Apache-2.0
00007  *
00008  * Licensed under the Apache License, Version 2.0 (the "License");
00009  * you may not use this file except in compliance with the License.
00010  * You may obtain a copy of the License at
00011  *
00012  *     http://www.apache.org/licenses/LICENSE-2.0
00013  *
00014  * Unless required by applicable law or agreed to in writing, software
00015  * distributed under the License is distributed on an "AS IS" BASIS,
00016  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00017  * See the License for the specific language governing permissions and
00018  * limitations under the License.
00019  */
00020 #ifndef MBED_I2C_API_H
00021 #define MBED_I2C_API_H
00022 
00023 #include "device.h"
00024 #include "hal/buffer.h"
00025 
00026 #if DEVICE_I2C_ASYNCH
00027 #include "hal/dma_api.h"
00028 #endif
00029 
00030 #if DEVICE_I2C
00031 
00032 /**
00033  * @defgroup hal_I2CEvents I2C Events Macros
00034  *
00035  * @{
00036  */
00037 #define I2C_EVENT_ERROR               (1 << 1)
00038 #define I2C_EVENT_ERROR_NO_SLAVE      (1 << 2)
00039 #define I2C_EVENT_TRANSFER_COMPLETE   (1 << 3)
00040 #define I2C_EVENT_TRANSFER_EARLY_NACK (1 << 4)
00041 #define I2C_EVENT_ALL                 (I2C_EVENT_ERROR |  I2C_EVENT_TRANSFER_COMPLETE | I2C_EVENT_ERROR_NO_SLAVE | I2C_EVENT_TRANSFER_EARLY_NACK)
00042 
00043 /**@}*/
00044 
00045 #if DEVICE_I2C_ASYNCH
00046 /** Asynch I2C HAL structure
00047  */
00048 typedef struct {
00049     struct i2c_s    i2c;     /**< Target specific I2C structure */
00050     struct buffer_s tx_buff; /**< Tx buffer */
00051     struct buffer_s rx_buff; /**< Rx buffer */
00052 } i2c_t;
00053 
00054 #else
00055 /** Non-asynch I2C HAL structure
00056  */
00057 typedef struct i2c_s i2c_t;
00058 
00059 #endif
00060 
00061 enum {
00062     I2C_ERROR_NO_SLAVE = -1,
00063     I2C_ERROR_BUS_BUSY = -2
00064 };
00065 
00066 #ifdef __cplusplus
00067 extern "C" {
00068 #endif
00069 
00070 /**
00071  * \defgroup hal_GeneralI2C I2C Configuration Functions
00072  * @{
00073  */
00074 
00075 /** Initialize the I2C peripheral. It sets the default parameters for I2C
00076  *  peripheral, and configures its specifieds pins.
00077  *
00078  *  @param obj  The I2C object
00079  *  @param sda  The sda pin
00080  *  @param scl  The scl pin
00081  */
00082 void i2c_init(i2c_t *obj, PinName sda, PinName scl);
00083 
00084 /** Configure the I2C frequency
00085  *
00086  *  @param obj The I2C object
00087  *  @param hz  Frequency in Hz
00088  */
00089 void i2c_frequency(i2c_t *obj, int hz);
00090 
00091 /** Send START command
00092  *
00093  *  @param obj The I2C object
00094  */
00095 int  i2c_start(i2c_t *obj);
00096 
00097 /** Send STOP command
00098  *
00099  *  @param obj The I2C object
00100  */
00101 int  i2c_stop(i2c_t *obj);
00102 
00103 /** Blocking reading data
00104  *
00105  *  @param obj     The I2C object
00106  *  @param address 7-bit address (last bit is 1)
00107  *  @param data    The buffer for receiving
00108  *  @param length  Number of bytes to read
00109  *  @param stop    Stop to be generated after the transfer is done
00110  *  @return Number of read bytes
00111  */
00112 int i2c_read(i2c_t *obj, int address, char *data, int length, int stop);
00113 
00114 /** Blocking sending data
00115  *
00116  *  @param obj     The I2C object
00117  *  @param address 7-bit address (last bit is 0)
00118  *  @param data    The buffer for sending
00119  *  @param length  Number of bytes to write
00120  *  @param stop    Stop to be generated after the transfer is done
00121  *  @return
00122  *      zero or non-zero - Number of written bytes
00123  *      negative - I2C_ERROR_XXX status
00124  */
00125 int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop);
00126 
00127 /** Reset I2C peripheral. TODO: The action here. Most of the implementation sends stop()
00128  *
00129  *  @param obj The I2C object
00130  */
00131 void i2c_reset(i2c_t *obj);
00132 
00133 /** Read one byte
00134  *
00135  *  @param obj The I2C object
00136  *  @param last Acknoledge
00137  *  @return The read byte
00138  */
00139 int i2c_byte_read(i2c_t *obj, int last);
00140 
00141 /** Write one byte
00142  *
00143  *  @param obj The I2C object
00144  *  @param data Byte to be written
00145  *  @return 0 if NAK was received, 1 if ACK was received, 2 for timeout.
00146  */
00147 int i2c_byte_write(i2c_t *obj, int data);
00148 
00149 /**@}*/
00150 
00151 #if DEVICE_I2CSLAVE
00152 
00153 /**
00154  * \defgroup SynchI2C Synchronous I2C Hardware Abstraction Layer for slave
00155  * @{
00156  */
00157 
00158 /** Configure I2C as slave or master.
00159  *  @param obj The I2C object
00160  *  @param enable_slave Enable i2c hardware so you can receive events with ::i2c_slave_receive
00161  *  @return non-zero if a value is available
00162  */
00163 void i2c_slave_mode(i2c_t *obj, int enable_slave);
00164 
00165 /** Check to see if the I2C slave has been addressed.
00166  *  @param obj The I2C object
00167  *  @return The status - 1 - read addresses, 2 - write to all slaves,
00168  *         3 write addressed, 0 - the slave has not been addressed
00169  */
00170 int  i2c_slave_receive(i2c_t *obj);
00171 
00172 /** Configure I2C as slave or master.
00173  *  @param obj The I2C object
00174  *  @param data    The buffer for receiving
00175  *  @param length  Number of bytes to read
00176  *  @return non-zero if a value is available
00177  */
00178 int  i2c_slave_read(i2c_t *obj, char *data, int length);
00179 
00180 /** Configure I2C as slave or master.
00181  *  @param obj The I2C object
00182  *  @param data    The buffer for sending
00183  *  @param length  Number of bytes to write
00184  *  @return non-zero if a value is available
00185  */
00186 int  i2c_slave_write(i2c_t *obj, const char *data, int length);
00187 
00188 /** Configure I2C address.
00189  *  @param obj     The I2C object
00190  *  @param idx     Currently not used
00191  *  @param address The address to be set
00192  *  @param mask    Currently not used
00193  */
00194 void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask);
00195 
00196 #endif
00197 
00198 /**@}*/
00199 
00200 #if DEVICE_I2C_ASYNCH
00201 
00202 /**
00203  * \defgroup hal_AsynchI2C Asynchronous I2C Hardware Abstraction Layer
00204  * @{
00205  */
00206 
00207 /** Start I2C asynchronous transfer
00208  *
00209  *  @param obj       The I2C object
00210  *  @param tx        The transmit buffer
00211  *  @param tx_length The number of bytes to transmit
00212  *  @param rx        The receive buffer
00213  *  @param rx_length The number of bytes to receive
00214  *  @param address   The address to be set - 7bit or 9bit
00215  *  @param stop      If true, stop will be generated after the transfer is done
00216  *  @param handler   The I2C IRQ handler to be set
00217  *  @param event     Event mask for the transfer. See \ref hal_I2CEvents
00218  *  @param hint      DMA hint usage
00219  */
00220 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);
00221 
00222 /** The asynchronous IRQ handler
00223  *
00224  *  @param obj The I2C object which holds the transfer information
00225  *  @return Event flags if a transfer termination condition was met, otherwise return 0.
00226  */
00227 uint32_t i2c_irq_handler_asynch(i2c_t *obj);
00228 
00229 /** Attempts to determine if the I2C peripheral is already in use
00230  *
00231  *  @param obj The I2C object
00232  *  @return Non-zero if the I2C module is active or zero if it is not
00233  */
00234 uint8_t i2c_active(i2c_t *obj);
00235 
00236 /** Abort asynchronous transfer
00237  *
00238  *  This function does not perform any check - that should happen in upper layers.
00239  *  @param obj The I2C object
00240  */
00241 void i2c_abort_asynch(i2c_t *obj);
00242 
00243 #endif
00244 
00245 /**@}*/
00246 
00247 #ifdef __cplusplus
00248 }
00249 #endif
00250 
00251 #endif
00252 
00253 #endif
00254 
00255 /** @}*/