nci/jni/Pn544Interop.cpp

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*****************************************************************************
**
**  Description:    Implement operations that provide compatibility with NXP
**                  PN544 controller.  Specifically facilitate peer-to-peer
**                  operations with PN544 controller.
**
*****************************************************************************/
#include "Pn544Interop.h"
#include "IntervalTimer.h"
#include "Mutex.h"
#include "NfcTag.h"

#include <android-base/stringprintf.h>
#include <base/logging.h>

using android::base::StringPrintf;

extern bool nfc_debug_enabled;

namespace android {
extern void startStopPolling(bool isStartPolling);
}

/*****************************************************************************
**
** private variables and functions
**
*****************************************************************************/

static const int gIntervalTime =
    1000;  // millisecond between the check to restore polling
static IntervalTimer gTimer;
static Mutex gMutex;
static void pn544InteropStartPolling(
    union sigval);              // callback function for interval timer
static bool gIsBusy = false;    // is timer busy?
static bool gAbortNow = false;  // stop timer during next callback

/*******************************************************************************
**
** Function:        pn544InteropStopPolling
**
** Description:     Stop polling to let NXP PN544 controller poll.
**                  PN544 should activate in P2P mode.
**
** Returns:         None
**
*******************************************************************************/
void pn544InteropStopPolling() {
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: enter", __func__);
  gMutex.lock();
  gTimer.kill();
  android::startStopPolling(false);
  gIsBusy = true;
  gAbortNow = false;
  gTimer.set(gIntervalTime,
             pn544InteropStartPolling);  // after some time, start polling again
  gMutex.unlock();
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: exit", __func__);
}

/*******************************************************************************
**
** Function:        pn544InteropStartPolling
**
** Description:     Start polling when activation state is idle.
**                  sigval: Unused.
**
** Returns:         None
**
*******************************************************************************/
void pn544InteropStartPolling(union sigval) {
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: enter", __func__);
  gMutex.lock();
  NfcTag::ActivationState state = NfcTag::getInstance().getActivationState();

  if (gAbortNow) {
    DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: abort now", __func__);
    gIsBusy = false;
    goto TheEnd;
  }

  if (state == NfcTag::Idle) {
    DLOG_IF(INFO, nfc_debug_enabled)
        << StringPrintf("%s: start polling", __func__);
    android::startStopPolling(true);
    gIsBusy = false;
  } else {
    DLOG_IF(INFO, nfc_debug_enabled)
        << StringPrintf("%s: try again later", __func__);
    gTimer.set(
        gIntervalTime,
        pn544InteropStartPolling);  // after some time, start polling again
  }

TheEnd:
  gMutex.unlock();
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: exit", __func__);
}

/*******************************************************************************
**
** Function:        pn544InteropIsBusy
**
** Description:     Is the code performing operations?
**
** Returns:         True if the code is busy.
**
*******************************************************************************/
bool pn544InteropIsBusy() {
  bool isBusy = false;
  gMutex.lock();
  isBusy = gIsBusy;
  gMutex.unlock();
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s: %u", __func__, isBusy);
  return isBusy;
}

/*******************************************************************************
**
** Function:        pn544InteropAbortNow
**
** Description:     Request to abort all operations.
**
** Returns:         None.
**
*******************************************************************************/
void pn544InteropAbortNow() {
  DLOG_IF(INFO, nfc_debug_enabled) << StringPrintf("%s", __func__);
  gMutex.lock();
  gAbortNow = true;
  gMutex.unlock();
}