xref: /hardware/samsung_slsi/exynos5/mobicore/daemon/Kernel/CKMod.cpp

/** @addtogroup MCD_MCDIMPL_DAEMON_KERNEL
 * @{
 * @file
 *
 * Kernel Module Interface.
 *
 * <!-- Copyright Giesecke & Devrient GmbH 2009 - 2012 -->
 *
 * 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. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */
#include <cstdlib>

#include <fcntl.h>
#include <sys/mman.h>
#include <errno.h>

#include "CKMod.h"

#include "log.h"

#define INVALID_FILE_DESCRIPTOR          ((int)(-1))

//------------------------------------------------------------------------------
CKMod::CKMod(void)
{
    fdKMod = INVALID_FILE_DESCRIPTOR;
}


//------------------------------------------------------------------------------
CKMod::~CKMod(void)
{
    close();
}


//------------------------------------------------------------------------------
bool CKMod::isOpen(void)
{
    return (INVALID_FILE_DESCRIPTOR == fdKMod) ? false : true;
}


//------------------------------------------------------------------------------
mcResult_t CKMod::open(const char *deviceName)
{
    if (isOpen()) {
        LOG_W("already open");
        return MC_DRV_ERR_DEVICE_ALREADY_OPEN;
    }

    LOG_I(" Opening kernel module at %s.", deviceName);

    // open return -1 on error, "errno" is set with details
    int openRet = ::open(deviceName, O_RDWR);
    if (openRet == -1) {
        LOG_ERRNO("open");
        return MAKE_MC_DRV_KMOD_WITH_ERRNO(errno);
    }

    fdKMod = openRet;
    return MC_DRV_OK;
}


//------------------------------------------------------------------------------
void CKMod::close(
    void
)
{
    if (isOpen()) {
        if (::close(fdKMod) != 0) {
            LOG_ERRNO("close");
        } else {
            fdKMod = INVALID_FILE_DESCRIPTOR;
        }
    } else {
        LOG_W(" Kernel module device not open");
    }
}

/** @} */