File content as of revision 149:156823d33999:

/**
 *******************************************************************************
 * @file    i2c.c
 * @brief Implementation of an i2c api
 * @internal
 * @author  ON Semiconductor
 * $Rev: 3525 $
 * $Date: 2015-07-20 15:24:25 +0530 (Mon, 20 Jul 2015) $
 ******************************************************************************
 * Copyright 2016 Semiconductor Components Industries LLC (d/b/a “ON Semiconductor”).
 * All rights reserved.  This software and/or documentation is licensed by ON Semiconductor
 * under limited terms and conditions.  The terms and conditions pertaining to the software
 * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
 * (“ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software”) and
 * if applicable the software license agreement.  Do not use this software and/or
 * documentation unless you have carefully read and you agree to the limited terms and
 * conditions.  By using this software and/or documentation, you agree to the limited
 * terms and conditions.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
 * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
 * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 * @endinternal
 *
 * @ingroup i2c
 *
 */
#if DEVICE_I2C

#include "i2c.h"
#include "i2c_api.h"

#define I2C_READ_WRITE_BIT_MASK    0xFE

/* See i2c_api.h for details */
void i2c_init(i2c_t *obj, PinName sda, PinName scl)
{
    fI2cInit(obj, sda, scl);
}

/* See i2c_api.h for details */
void i2c_frequency(i2c_t *obj, int hz)
{
    fI2cFrequency(obj, hz);
}

/* See i2c_api.h for details */
int i2c_start(i2c_t *obj)
{
    return(fI2cStart(obj));
}

/* See i2c_api.h for details */
int i2c_stop(i2c_t *obj)
{
    return(fI2cStop(obj));
}

/* See i2c_api.h for details */
int i2c_read(i2c_t *obj, int address, char *data, int length, int stop)
{
    /* TODO address parameter not usable */
    int Count, status;
    const char WriteData = (address | (~I2C_READ_WRITE_BIT_MASK)) & 0xFF;

    /* Send  start bit */
    status = fI2cStart(obj);
    if(status) {
        /* Error sending start bit */
        return status;
    }

    /* Send address | read */
    Count = fI2cWriteB(obj, &WriteData, 1);
    if(Count != 1) {
        /* Error sending address */
        return Count;
    }

    /* Send command/s */
    Count = fI2cReadB(obj, data, length);
    if(Count != length) {
        /* Error sending coomand/s */
        return Count;
    }
    if(stop) {    /* Send stop bit if requested */
        status = fI2cStop(obj);
        if(status) {
            /* Error sending stop bit */
            return status;
        }
    }
    return Count;
}

/* See i2c_api.h for details */
int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop)
{
    int Count, status;
    const char WriteData = (address & I2C_READ_WRITE_BIT_MASK) & 0xFF;

    /* Send start bit */
    status = fI2cStart(obj);
    if(status) {
        /* Error sending start bit */
        return status;
    }

    /* Send address | write */
    Count = fI2cWriteB(obj, &WriteData, 1);
    if(Count != 1) {
        /* Error sending address */
        return Count;
    }

    /* Sens command, [data] */
    Count = fI2cWriteB(obj, data, length);
    if(Count != length) {
        /* Error sending address */
        return Count;
    }

    if(stop) {    /* If stop requested */
        /* Send stop bit */
        status = fI2cStop(obj);
        if(status) {
            /* Error sending stop bit */
            return status;
        }
    }
    return Count;
}

/* See i2c_api.h for details */
void i2c_reset(i2c_t *obj)
{
    (void)fI2cStop(obj);
}

/* See i2c_api.h for details */
int i2c_byte_read(i2c_t *obj, int last) /* TODO return size can be uint8_t */
{
    int Count;
    char data;
    Count = fI2cReadB(obj, &data, 1);
    if(Count != 1) {
        /* Error */
        return Count;
    }
    if(last) {
        /* ACK */
        obj->membase->CMD_REG = I2C_CMD_WDAT0;
    } else {
        /* No ACK */
        obj->membase->CMD_REG = I2C_CMD_WDAT1;
    }
    return data;
}

/* See i2c_api.h for details */
int i2c_byte_write(i2c_t *obj, int data)
{
    int Count;
    Count = fI2cWriteB(obj, (const char *)&data, 1);
    if(Count != 1) {
        return Count;
    }

    obj->membase->CMD_REG = I2C_CMD_VRFY_ACK; /* Verify ACK */

    while(obj->membase->STATUS.WORD & I2C_STATUS_CMD_FIFO_OFL_BIT); /* Wait till command overflow ends */

    if(obj->membase->STATUS.WORD & I2C_STATUS_BUS_ERR_BIT) {
        /* Bus error means NAK received */
        return 0;
    } else {
        /* ACK received */
        return 1;
    }
}

#endif /* DEVICE_I2C */