001package com.pi4j.io.i2c;
002
003/*
004 * #%L
005 * **********************************************************************
006 * ORGANIZATION  :  Pi4J
007 * PROJECT       :  Pi4J :: Java Library (Core)
008 * FILENAME      :  I2CFactory.java
009 *
010 * This file is part of the Pi4J project. More information about
011 * this project can be found here:  http://www.pi4j.com/
012 * **********************************************************************
013 * %%
014 * Copyright (C) 2012 - 2016 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.IOException;
033import java.util.concurrent.TimeUnit;
034
035import com.pi4j.io.i2c.impl.I2CFactoryProviderRaspberryPi;
036
037/**
038 * I2C factory - it returns instances of {@link I2CBus} interface.
039 *
040 * @author Robert Savage (<a href="http://www.savagehomeautomation.com">http://www .savagehomeautomation.com</a>)
041 */
042public class I2CFactory {
043
044    public static final long DEFAULT_LOCKAQUIRE_TIMEOUT = 1000;
045
046    public static final TimeUnit DEFAULT_LOCKAQUIRE_TIMEOUT_UNITS = TimeUnit.MILLISECONDS;
047
048    public static class UnsupportedBusNumberException extends Exception {
049        private static final long serialVersionUID = 1L;
050
051        public UnsupportedBusNumberException() {
052            super();
053        }
054    }
055
056    volatile static I2CFactoryProvider provider = new I2CFactoryProviderRaspberryPi();
057
058    // private constructor
059    private I2CFactory() {
060        // forbid object construction
061    }
062
063    /**
064     * Create new I2CBus instance.
065     * <p>
066     * The timeout for locking the bus for exclusive communication is set to DEFAULT_LOCKAQUIRE_TIMEOUT.
067     *
068     * @param busNumber The bus number
069     * @return Return a new I2CBus instance
070     * @throws UnsupportedBusNumberException If the given bus-number is not supported by the underlying system
071     * @throws IOException If communication to i2c-bus fails
072     * @see I2CProvider#DEFAULT_LOCKAQUIRE_TIMEOUT
073     * @see I2CProvider#DEFAULT_LOCKAQUIRE_TIMEOUT_UNITS
074     */
075    public static I2CBus getInstance(int busNumber) throws UnsupportedBusNumberException, IOException {
076        return provider.getBus(busNumber, DEFAULT_LOCKAQUIRE_TIMEOUT, DEFAULT_LOCKAQUIRE_TIMEOUT_UNITS);
077    }
078
079    /**
080     * Create new I2CBus instance.
081     *
082     * @param busNumber The bus number
083     * @param lockAquireTimeout The timeout for locking the bus for exclusive communication
084     * @param lockAquireTimeoutUnit The units of lockAquireTimeout
085     * @return Return a new I2CBus instance
086     * @throws UnsupportedBusNumberException If the given bus-number is not supported by the underlying system
087     * @throws IOException If communication to i2c-bus fails
088     */
089    public static I2CBus getInstance(int busNumber, long lockAquireTimeout, TimeUnit lockAquireTimeoutUnit) throws UnsupportedBusNumberException, IOException {
090        return provider.getBus(busNumber, lockAquireTimeout, lockAquireTimeoutUnit);
091    }
092
093    /**
094     * allow changing the provider for the factory
095     *
096     * @param factoryProvider
097     */
098    public static void setFactory(I2CFactoryProvider factoryProvider) {
099        provider = factoryProvider;
100    }
101
102}