mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-08-14 09:28:59 +00:00
137 lines
3.5 KiB
C
137 lines
3.5 KiB
C
|
/*
|
||
|
* Copyright (c) 2013, IDentification Automation Laboratory
|
||
|
* IDALab (http://www.idalab.unisalento.it)
|
||
|
* Department of Innovation Engineering - University of Salento
|
||
|
*
|
||
|
* All rights reserved.
|
||
|
*
|
||
|
* Redistribution and use in source and binary forms, with or without
|
||
|
* modification, are permitted provided that the following conditions
|
||
|
* are met:
|
||
|
* 1. Redistributions of source code must retain the above copyright
|
||
|
* notice, this list of conditions and the following disclaimer.
|
||
|
* 2. Redistributions in binary form must reproduce the above copyright
|
||
|
* notice, this list of conditions and the following disclaimer in the
|
||
|
* documentation and/or other materials provided with the distribution.
|
||
|
* 3. Neither the name of the Institute nor the names of its contributors
|
||
|
* may be used to endorse or promote products derived from this software
|
||
|
* without specific prior written permission.
|
||
|
*
|
||
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
||
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
||
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
|
* SUCH DAMAGE.
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
/**
|
||
|
* \file i2c.c
|
||
|
* \brief I2C bus master driver for mbxxx platform.
|
||
|
* \author Maria Laura Stefanizzi <laura28582@gmail.com>
|
||
|
* \date 2013-11-20
|
||
|
*/
|
||
|
|
||
|
#include <stdio.h>
|
||
|
#include <contiki.h>
|
||
|
#include "dev/i2c.h"
|
||
|
#include PLATFORM_HEADER
|
||
|
|
||
|
#define WAIT_FIN_SC2(FLAG) while(!SC2_STAT(FLAG)) {}
|
||
|
|
||
|
/**
|
||
|
* Configure serial controller in I2C mode and set I2C speed.
|
||
|
*/
|
||
|
void
|
||
|
i2c_enable(void)
|
||
|
{
|
||
|
/* Configure serial controller to I2C mode */
|
||
|
SC2_MODE = SC2_MODE_I2C;
|
||
|
|
||
|
/*
|
||
|
* The SCL is produced by dividing down 12MHz according to
|
||
|
* this equation:
|
||
|
* Rate = 12 MHz / ( (LIN + 1) * (2^EXP) )
|
||
|
*
|
||
|
* Configure rate registers for Fast Mode operation (400 kbps)
|
||
|
*/
|
||
|
SC2_RATELIN = 14;
|
||
|
SC2_RATEEXP = 1;
|
||
|
|
||
|
/* Reset control registers */
|
||
|
SC2_TWICTRL1 = SC2_TWICTRL1_RESET;
|
||
|
SC2_TWICTRL2 = SC2_TWICTRL2_RESET;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Configure serial controller in disabled mode
|
||
|
*/
|
||
|
void
|
||
|
i2c_disable(void)
|
||
|
{
|
||
|
SC2_MODE = SC2_MODE_DISABLED;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Generate I2C START condition
|
||
|
*/
|
||
|
void
|
||
|
i2c_start(void)
|
||
|
{
|
||
|
SC2_TWICTRL1 |= SC_TWISTART;
|
||
|
WAIT_FIN_SC2(SC_TWICMDFIN);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Generate I2C STOP condition
|
||
|
*/
|
||
|
void
|
||
|
i2c_stop(void)
|
||
|
{
|
||
|
SC2_TWICTRL1 |= SC_TWISTOP;
|
||
|
WAIT_FIN_SC2(SC_TWICMDFIN);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Send a byte to I2C bus
|
||
|
* @param data The data that must be sent
|
||
|
*/
|
||
|
void
|
||
|
i2c_write(uint8_t data)
|
||
|
{
|
||
|
SC2_DATA = data;
|
||
|
|
||
|
/* Configure control register 1 for byte transmission */
|
||
|
SC2_TWICTRL1 |= SC_TWISEND;
|
||
|
WAIT_FIN_SC2(SC_TWITXFIN);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Read a byte from I2C bus
|
||
|
* @param ack If true enable ACK generation after byte reception
|
||
|
* @return The received byte
|
||
|
*/
|
||
|
uint8_t
|
||
|
i2c_read(int ack)
|
||
|
{
|
||
|
if(ack) {
|
||
|
/* Enable ACK generation after current received byte */
|
||
|
SC2_TWICTRL2 |= SC_TWIACK;
|
||
|
} else {
|
||
|
/* Disable ACK generation */
|
||
|
SC2_TWICTRL2 &= ~SC_TWIACK;
|
||
|
}
|
||
|
|
||
|
/* Configure control register 1 for byte reception */
|
||
|
SC2_TWICTRL1 |= SC_TWIRECV;
|
||
|
WAIT_FIN_SC2(SC_TWIRXFIN);
|
||
|
|
||
|
return SC2_DATA;
|
||
|
}
|