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hal/i2c_api.h
- Committer:
- amithy
- Date:
- 2017-11-09
- Revision:
- 178:c26431f84b0d
- Parent:
- 153:fa9ff456f731
- Child:
- 172:7d866c31b3c5
File content as of revision 178:c26431f84b0d:
/** \addtogroup hal */ /** @{*/ /* mbed Microcontroller Library * Copyright (c) 2006-2015 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBED_I2C_API_H #define MBED_I2C_API_H #include "device.h" #include "hal/buffer.h" #if DEVICE_I2C_ASYNCH #include "hal/dma_api.h" #endif #if DEVICE_I2C /** * @defgroup hal_I2CEvents I2C Events Macros * * @{ */ #define I2C_EVENT_ERROR (1 << 1) #define I2C_EVENT_ERROR_NO_SLAVE (1 << 2) #define I2C_EVENT_TRANSFER_COMPLETE (1 << 3) #define I2C_EVENT_TRANSFER_EARLY_NACK (1 << 4) #define I2C_EVENT_ALL (I2C_EVENT_ERROR | I2C_EVENT_TRANSFER_COMPLETE | I2C_EVENT_ERROR_NO_SLAVE | I2C_EVENT_TRANSFER_EARLY_NACK) /**@}*/ #if DEVICE_I2C_ASYNCH /** Asynch I2C HAL structure */ typedef struct { struct i2c_s i2c; /**< Target specific I2C structure */ struct buffer_s tx_buff; /**< Tx buffer */ struct buffer_s rx_buff; /**< Rx buffer */ } i2c_t; #else /** Non-asynch I2C HAL structure */ typedef struct i2c_s i2c_t; #endif enum { I2C_ERROR_NO_SLAVE = -1, I2C_ERROR_BUS_BUSY = -2 }; #ifdef __cplusplus extern "C" { #endif /** * \defgroup hal_GeneralI2C I2C Configuration Functions * @{ */ /** Initialize the I2C peripheral. It sets the default parameters for I2C * peripheral, and configures its specifieds pins. * * @param obj The I2C object * @param sda The sda pin * @param scl The scl pin */ void i2c_init(i2c_t *obj, PinName sda, PinName scl); /** Configure the I2C frequency * * @param obj The I2C object * @param hz Frequency in Hz */ void i2c_frequency(i2c_t *obj, int hz); /** Send START command * * @param obj The I2C object */ int i2c_start(i2c_t *obj); /** Send STOP command * * @param obj The I2C object */ int i2c_stop(i2c_t *obj); /** Blocking reading data * * @param obj The I2C object * @param address 7-bit address (last bit is 1) * @param data The buffer for receiving * @param length Number of bytes to read * @param stop Stop to be generated after the transfer is done * @return Number of read bytes */ int i2c_read(i2c_t *obj, int address, char *data, int length, int stop); /** Blocking sending data * * @param obj The I2C object * @param address 7-bit address (last bit is 0) * @param data The buffer for sending * @param length Number of bytes to write * @param stop Stop to be generated after the transfer is done * @return * zero or non-zero - Number of written bytes * negative - I2C_ERROR_XXX status */ int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop); /** Reset I2C peripheral. TODO: The action here. Most of the implementation sends stop() * * @param obj The I2C object */ void i2c_reset(i2c_t *obj); /** Read one byte * * @param obj The I2C object * @param last Acknoledge * @return The read byte */ int i2c_byte_read(i2c_t *obj, int last); /** Write one byte * * @param obj The I2C object * @param data Byte to be written * @return 0 if NAK was received, 1 if ACK was received, 2 for timeout. */ int i2c_byte_write(i2c_t *obj, int data); /**@}*/ #if DEVICE_I2CSLAVE /** * \defgroup SynchI2C Synchronous I2C Hardware Abstraction Layer for slave * @{ */ /** Configure I2C as slave or master. * @param obj The I2C object * @return non-zero if a value is available */ void i2c_slave_mode(i2c_t *obj, int enable_slave); /** Check to see if the I2C slave has been addressed. * @param obj The I2C object * @return The status - 1 - read addresses, 2 - write to all slaves, * 3 write addressed, 0 - the slave has not been addressed */ int i2c_slave_receive(i2c_t *obj); /** Configure I2C as slave or master. * @param obj The I2C object * @return non-zero if a value is available */ int i2c_slave_read(i2c_t *obj, char *data, int length); /** Configure I2C as slave or master. * @param obj The I2C object * @return non-zero if a value is available */ int i2c_slave_write(i2c_t *obj, const char *data, int length); /** Configure I2C address. * @param obj The I2C object * @param idx Currently not used * @param address The address to be set * @param mask Currently not used */ void i2c_slave_address(i2c_t *obj, int idx, uint32_t address, uint32_t mask); #endif /**@}*/ #if DEVICE_I2C_ASYNCH /** * \defgroup hal_AsynchI2C Asynchronous I2C Hardware Abstraction Layer * @{ */ /** Start I2C asynchronous transfer * * @param obj The I2C object * @param tx The transmit buffer * @param tx_length The number of bytes to transmit * @param rx The receive buffer * @param rx_length The number of bytes to receive * @param address The address to be set - 7bit or 9bit * @param stop If true, stop will be generated after the transfer is done * @param handler The I2C IRQ handler to be set * @param hint DMA hint usage */ 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); /** The asynchronous IRQ handler * * @param obj The I2C object which holds the transfer information * @return Event flags if a transfer termination condition was met, otherwise return 0. */ uint32_t i2c_irq_handler_asynch(i2c_t *obj); /** Attempts to determine if the I2C peripheral is already in use * * @param obj The I2C object * @return Non-zero if the I2C module is active or zero if it is not */ uint8_t i2c_active(i2c_t *obj); /** Abort asynchronous transfer * * This function does not perform any check - that should happen in upper layers. * @param obj The I2C object */ void i2c_abort_asynch(i2c_t *obj); #endif /**@}*/ #ifdef __cplusplus } #endif #endif #endif /** @}*/