eive-obsw/thirdparty/libcsp/include/csp/drivers/i2c.h

121 lines
3.1 KiB
C

/*
Cubesat Space Protocol - A small network-layer protocol designed for Cubesats
Copyright (C) 2012 GomSpace ApS (http://www.gomspace.com)
Copyright (C) 2012 AAUSAT3 Project (http://aausat3.space.aau.dk)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Common I2C interface,
* This file is derived from the Gomspace I2C driver,
*
*/
#ifndef I2C_H_
#define I2C_H_
#ifdef __cplusplus
extern "C" {
#endif
/**
* The return value of the driver is a bit strange,
* It should return E_NO_ERR if successfull and the value is -1
*/
#define E_NO_ERR -1
/**
* Maximum transfer length on I2C
*/
#define I2C_MTU 256
/**
I2C device modes
@{
*/
/**
I2C Master mode.
*/
#define I2C_MASTER 0
/**
I2C Slave mode.
*/
#define I2C_SLAVE 1
/**@}*/
/**
Data structure for I2C frames.
This structs fits on top of #csp_packet_t, removing the need for copying data.
*/
typedef struct __attribute__((packed)) i2c_frame_s {
//! Not used by CSP
uint8_t padding;
//! Not used by CSP - cleared before Tx
uint8_t retries;
//! Not used by CSP
uint32_t reserved;
//! Destination address
uint8_t dest;
//! Not used by CSP - cleared before Tx
uint8_t len_rx;
//! Length of \a data part
uint16_t len;
//! CSP data
uint8_t data[I2C_MTU];
} i2c_frame_t;
/**
Callback for receiving data.
@param[in] frame received I2C frame
@param[out] pxTaskWoken can be set, if context switch is required due to received data.
*/
typedef void (*i2c_callback_t) (i2c_frame_t * frame, void * pxTaskWoken);
/**
Initialise the I2C driver
Functions is called by csp_i2c_init().
@param handle Which I2C bus (if more than one exists)
@param mode I2C device mode. Must be either I2C_MASTER or I2C_SLAVE
@param addr Own slave address
@param speed Bus speed in kbps
@param queue_len_tx Length of transmit queue
@param queue_len_rx Length of receive queue
@param callback If this value is set, the driver will call this function instead of using an RX queue
@return Error code
*/
int i2c_init(int handle, int mode, uint8_t addr, uint16_t speed, int queue_len_tx, int queue_len_rx, i2c_callback_t callback);
/**
User I2C transmit function.
Called by CSP, when sending message over I2C.
@param handle Handle to the device
@param frame Pointer to I2C frame
@param timeout Ticks to wait
@return Error code
*/
int i2c_send(int handle, i2c_frame_t * frame, uint16_t timeout);
#ifdef __cplusplus
}
#endif
#endif