bsproxy/proxdev_i2c.c

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////////////////////////////////////////////////////////////////////////////////
//
// Package:   botsense
//
// File:      proxdev_i2c.c
//
/*! \file
 *
 * \version $LastChangedDate$ $Rev$
 *
 * \brief I2C proxied device operations.
 *
 * All operations are multi-threaded protected by a mutual exclusion.
 *
 * \author Robin Knight (robin.knight@roadnarrows.com)
 *
 * \par Copyright:
 * (C) 2007.  RoadNarrows LLC.
 * (http://www.roadnarrows.com)
 * \n All Rights Reserved
 */
// Permission is hereby granted, without written agreement and without
// license or royalty fees, to use, copy, modify, and distribute this
// software and its documentation for any purpose, provided that
// (1) The above copyright notice and the following two paragraphs
// appear in all copies of the source code and (2) redistributions
// including binaries reproduces these notices in the supporting
// documentation.   Substantial modifications to this software may be
// copyrighted by their authors and need not follow the licensing terms
// described here, provided that the new terms are clearly indicated in
// all files where they apply.
//
// IN NO EVENT SHALL THE AUTHOR, ROADNARROWS LLC, OR ANY MEMBERS/EMPLOYEES
// OF ROADNARROW LLC OR DISTRIBUTORS OF THIS SOFTWARE BE LIABLE TO ANY
// PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION,
// EVEN IF THE AUTHORS OR ANY OF THE ABOVE PARTIES HAVE BEEN ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
// THE AUTHOR AND ROADNARROWS LLC SPECIFICALLY DISCLAIM ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN
// "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO
// PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
//
////////////////////////////////////////////////////////////////////////////////

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "rnr/rnrconfig.h"
#include "rnr/log.h"

#include "i2ccom.h"

#include "bsproxy.h"


// ---------------------------------------------------------------------------
// Private Interface 
// ---------------------------------------------------------------------------

#ifdef ARCH_armpxa
#define I2C_DEV_NAME_DFT  "/dev/i2c/0"    ///< default I2C device
#else
#define I2C_DEV_NAME_DFT  "/dev/i2c-0"    ///< default I2C device
#endif

//
// Data
//
static byte_t i2c_scanned_dev[128];       ///< scanned device vector
static byte_t i2c_scanned_cnt;            ///< scanned device count

/*!
 * \brief Scanned device callback.
 *
 * \param pI2C      libi2c interface.
 * \param addr      I2C discovered address
 * \param context   Scan context (not used).
 *
 * \return Returns 1 for success.
 */
static int cb_i2c_scan(i2c_t *pI2C, i2c_dev_t addr, void *context)
{
  i2c_scanned_dev[i2c_scanned_cnt++] = (byte_t)addr;
  return 1;
}
 

// ---------------------------------------------------------------------------
// Public Interface 
// ---------------------------------------------------------------------------

/*!
 * \brief Scan I<sup>2</sup>C Bus for attached address.
 *
 * The addresses of all discovered devices are returned.
 *
 * \param      pProxDev Proxied device.
 * \param[out] bufScan  Vector of addresses of discovered devices from scan.
 * \param      sizeBuf  Size of scan buffer.
 *
 * \return Returns number of discovered devices.
 */
int ProxDevI2CScan(BsProxyDev_T *pProxDev, byte_t bufScan[], size_t sizeBuf)
{
  i2c_t     i2c;
  int       n;

  pthread_mutex_lock(&pProxDev->m_mutDev);
  
  i2c.fd  = pProxDev->m_unDevSpec.i2c.m_fd;
  i2c.dev = 0;

  i2c_scanned_cnt = 0;

  i2c_scan(&i2c, cb_i2c_scan, NULL);

  for(n=0; n<i2c_scanned_cnt && n<sizeBuf; ++n)
  {
    bufScan[n] = i2c_scanned_dev[n];
  }

  pthread_mutex_unlock(&pProxDev->m_mutDev);

  return n;
}

/*!
 * \brief Perform a write/read transaction between an I<sup>2</sup>C device.
 *
 * \param     pProxDev    Proxied device.
 * \param     i2cAddr     I<sup>2</sup>C address.
 * \param     bufWrite    Write buffer.
 * \param     countWrite  Number of bytes to write from write buffer to device.
 * \param[out] bufRead    Read buffer.
 * \param     countRead   Number of bytes to read from device to read buffer.
 *
 * \return Returns number of bytes read on success, <=0 on error.
 */
int ProxDevI2CTrans(BsProxyDev_T *pProxDev, uint_t i2cAddr,
                    byte_t bufWrite[], size_t countWrite,
                    byte_t bufRead[], size_t countRead)
{
  i2c_t     i2c;
  int       n;

  pthread_mutex_lock(&pProxDev->m_mutDev);
  
  i2c.fd  = pProxDev->m_unDevSpec.i2c.m_fd;
  i2c.dev = i2cAddr;

  n = i2c_lltransfer(&i2c, i2cAddr,
                     (char *)bufWrite, (uint_t)countWrite,
                     (char *)bufRead, (uint_t)countRead);

  if( n <= 0 )
  {
    LOGSYSERROR("%s: i2c_lltransfer(0x%02x...)", pProxDev->m_sDevName, i2cAddr);
  }

  pthread_mutex_unlock(&pProxDev->m_mutDev);

  return n;
}

/*!
 * \brief Write buffer to an I<sup>2</sup>C device.
 *
 * \param pProxDev      Proxied device.
 * \param i2cAddr       I<sup>2</sup>C address.
 * \param bufWrite      Write buffer.
 * \param countWrite    Number of bytes to write from write buffer to device.
 *
 * \return Returns number of bytes written on success, <=0 on error.
 */
int ProxDevI2CWrite(BsProxyDev_T *pProxDev, uint_t i2cAddr,
                    byte_t bufWrite[], size_t countWrite)
{
  i2c_t     i2c;
  int       n;

  pthread_mutex_lock(&pProxDev->m_mutDev);
  
  i2c.fd  = pProxDev->m_unDevSpec.i2c.m_fd;
  i2c.dev = 0;

  n = i2c_llwrite(&i2c, i2cAddr, (char *)bufWrite, (uint_t)countWrite);

  if( n <= 0 )
  {
    LOGSYSERROR("%s: i2c_llwrite(0x%02x...)", pProxDev->m_sDevName, i2cAddr);
  }

  pthread_mutex_unlock(&pProxDev->m_mutDev);

  return n;
}

/*!
 * \brief Read bytes from an I<sup>2</sup>C device.
 *
 * \param       pProxDev  Proxied device.
 * \param       i2cAddr   I<sup>2</sup>C address.
 * \param[out]  bufRead   Read buffer.
 * \param       countRead Number of bytes to read from device to read buffer.
 *
 * \return Returns number of bytes read on success, <=0 on error.
 */
int ProxDevI2CRead(BsProxyDev_T *pProxDev, uint_t i2cAddr,
                   byte_t bufRead[], size_t countRead)
{
  i2c_t     i2c;
  int       n;

  pthread_mutex_lock(&pProxDev->m_mutDev);
  
  i2c.fd  = pProxDev->m_unDevSpec.i2c.m_fd;
  i2c.dev = 0;

  n = i2c_llread(&i2c, i2cAddr, (char *)bufRead, (uint_t)countRead);

  if( n <= 0 )
  {
    LOGSYSERROR("%s: i2c_llread(0x%02x...)", pProxDev->m_sDevName, i2cAddr);
  }

  pthread_mutex_unlock(&pProxDev->m_mutDev);

  return n;
}

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