001package com.pi4j.io.i2c.impl;
002
003/*
004 * #%L
005 * **********************************************************************
006 * ORGANIZATION  :  Pi4J
007 * PROJECT       :  Pi4J :: Java Library (Core)
008 * FILENAME      :  I2CProviderImpl.java
009 *
010 * This file is part of the Pi4J project. More information about
011 * this project can be found here:  https://www.pi4j.com/
012 * **********************************************************************
013 * %%
014 * Copyright (C) 2012 - 2019 Pi4J
015 * %%
016 * This program is free software: you can redistribute it and/or modify
017 * it under the terms of the GNU Lesser General Public License as
018 * published by the Free Software Foundation, either version 3 of the
019 * License, or (at your option) any later version.
020 *
021 * This program is distributed in the hope that it will be useful,
022 * but WITHOUT ANY WARRANTY; without even the implied warranty of
023 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
024 * GNU General Lesser Public License for more details.
025 *
026 * You should have received a copy of the GNU General Lesser Public
027 * License along with this program.  If not, see
028 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
029 * #L%
030 */
031
032import java.io.File;
033import java.io.IOException;
034
035import java.util.concurrent.TimeUnit;
036
037import com.pi4j.io.i2c.I2CBus;
038import com.pi4j.io.i2c.I2CFactory.UnsupportedBusNumberException;
039import com.pi4j.io.i2c.I2CFactoryProvider;
040
041public class I2CProviderImpl implements I2CFactoryProvider {
042
043    public I2CProviderImpl() {
044    }
045
046    public I2CBus getBus(final int busNumber, final long lockAquireTimeout, final TimeUnit lockAquireTimeoutUnit) throws UnsupportedBusNumberException, IOException {
047        final File sysfs = new File("/sys/bus/i2c/devices/i2c-" + busNumber);
048        if (!sysfs.exists() || !sysfs.isDirectory()) {
049            throw new UnsupportedBusNumberException();
050        }
051
052        final File devfs = new File("/dev/i2c-" + busNumber);
053        if (!devfs.exists() || !devfs.canRead() || !devfs.canWrite()) {
054            throw new UnsupportedBusNumberException();
055        }
056
057        I2CBusImpl result = new I2CBusImpl(busNumber, devfs.getCanonicalPath(), lockAquireTimeout, lockAquireTimeoutUnit);
058        result.open();
059
060        return result;
061    }
062}