com.diozero.internal.provider.sysfs.NativeI2CDeviceSMBus Maven / Gradle / Ivy
package com.diozero.internal.provider.sysfs;
/*
* #%L
* Organisation: mattjlewis
* Project: Device I/O Zero - Core
* Filename: NativeI2CDeviceSMBus.java
*
* This file is part of the diozero project. More information about this project
* can be found at http://www.diozero.com/
* %%
* Copyright (C) 2016 - 2017 mattjlewis
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
import org.pmw.tinylog.Logger;
import com.diozero.api.DeviceBusyException;
import com.diozero.api.I2CDevice;
import com.diozero.util.RuntimeIOException;
/**
* JNI wrapper of SMBus interface.
* Reference Kernel I2C dev interface
* and SMBus Protocol.
* See i2c-dev for defintion of the inline functions.
* See Python CFFI implementation.
*/
public class NativeI2CDeviceSMBus implements I2CSMBusInterface {
private static final int CLOSED = -1;
private int controller;
private int deviceAddress;
private int fd = CLOSED;
private int funcs;
public NativeI2CDeviceSMBus(int controller, int deviceAddress, boolean force)
throws RuntimeIOException {
this.controller = controller;
this.deviceAddress = deviceAddress;
String device_file = "/dev/i2c-" + controller;
int rc = NativeI2C.smbusOpen(device_file, deviceAddress, force);
if (rc < 0) {
if (rc == -16) {
throw new DeviceBusyException("Error, I2C device " + controller + "-0x"
+ Integer.toHexString(deviceAddress) + " is busy");
}
throw new RuntimeIOException(rc);
}
fd = rc;
rc = NativeI2C.getFuncs(fd);
if (rc < 0) {
close();
throw new RuntimeIOException("Error reading I2C_FUNCS for device i2c-" + controller + "-0x"
+ Integer.toHexString(deviceAddress) + ": " + rc);
}
funcs = rc;
Logger.debug("I2C_FUNCS for controller {}: 0x{}", Integer.toString(controller), Integer.toHexString(funcs));
}
@Override
public void close() {
NativeI2C.smbusClose(fd);
fd = CLOSED;
}
@Override
/*
* Code ported from i2c-tools.
*/
public boolean probe(I2CDevice.ProbeMode mode) {
int res;
switch (mode) {
case QUICK:
/* This is known to corrupt the Atmel AT24RF08 EEPROM */
res = NativeI2C.writeQuick(fd, NativeI2C.I2C_SMBUS_WRITE);
break;
case READ:
/* This is known to lock SMBus on various write-only chips (mainly clock chips) */
res = NativeI2C.readByte(fd);
break;
default:
if ((deviceAddress >= 0x30 && deviceAddress <= 0x37) || (deviceAddress >= 0x50 && deviceAddress <= 0x5F) ||
(funcs & NativeI2C.I2C_FUNC_SMBUS_QUICK) == 0) {
res = NativeI2C.readByte(fd);
} else {
res = NativeI2C.writeQuick(fd, NativeI2C.I2C_SMBUS_WRITE);
}
}
return res >= 0;
}
@Override
public void writeQuick(byte bit) {
if ((funcs & NativeI2C.I2C_FUNC_SMBUS_QUICK) == 0) {
Logger.warn("Function I2C_FUNC_SMBUS_QUICK isn't supported for device i2c-{}-0x{}",
Integer.valueOf(controller), Integer.toHexString(deviceAddress));
// TODO Throw an exception now or attempt anyway?
}
int rc = NativeI2C.writeQuick(fd, bit);
if (rc < 0) {
throw new RuntimeIOException("Error in SMBus.writeQuick for device i2c-" + controller + "-0x"
+ Integer.toHexString(deviceAddress) + ": " + rc);
}
}
@Override
public byte readByte() {
if ((funcs & NativeI2C.I2C_FUNC_SMBUS_READ_BYTE) == 0) {
Logger.warn("Function I2C_FUNC_SMBUS_READ_BYTE isn't supported for device i2c-{}-0x{}",
Integer.valueOf(controller), Integer.toHexString(deviceAddress));
// TODO Throw an exception now or attempt anyway?
}
int rc = NativeI2C.readByte(fd);
if (rc < 0) {
throw new RuntimeIOException("Error in SMBus.readByte for device i2c-" + controller + "-0x"
+ Integer.toHexString(deviceAddress) + ": " + rc);
}
return (byte) rc;
}
@Override
public void writeByte(byte data) {
if ((funcs & NativeI2C.I2C_FUNC_SMBUS_WRITE_BYTE) == 0) {
Logger.warn("Function I2C_FUNC_SMBUS_WRITE_BYTE isn't supported for device i2c-{}-0x{}",
Integer.valueOf(controller), Integer.toHexString(deviceAddress));
// TODO Throw an exception now or attempt anyway?
}
int rc = NativeI2C.writeByte(fd, data);
if (rc < 0) {
throw new RuntimeIOException("Error in SMBus.writeByte for device i2c-" + controller + "-0x"
+ Integer.toHexString(deviceAddress) + ": " + rc);
}
}
@Override
public byte[] readBytes(int length) {
/*
* byte[] data = new byte[length]; for (int i=0; i