rewrite ftdi driver without LGPL code from libftdi

README.md

@@ -158,9 +158,6 @@ complete license.
 
 Copyright 2011-2012, Google Inc. All Rights Reserved.
 
-Portions of this library are based on [libftdi](http://www.intra2net.com/en/developer/libftdi).
-Please see FtdiSerialDriver.java for more information.
-
 ## Help & Discussion
 
 For common problems, see the

usbSerialForAndroid/publishToMavenLocal.gradle

@@ -5,7 +5,7 @@ publishing {
         maven(MavenPublication) {
             groupId 'com.github.mik3y'
             artifactId 'usb-serial-for-android'
-            version '2.2.2a'
+            version '3.0.0beta'
             afterEvaluate {
                 artifact androidSourcesJar
                 artifact bundleReleaseAar

usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java

@@ -383,6 +383,44 @@ public class DeviceTest {
                 assertThat("42000/8N1", data2, equalTo(buf2));
             }
         }
+        if (usbSerialDriver instanceof FtdiSerialDriver) {
+            try {
+                usbParameters(183, 8, 1, UsbSerialPort.PARITY_NONE);
+                fail("baud rate to low expected");
+            } catch (IOException ignored) {
+            }
+            usbParameters(184, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters( 960000, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1000000, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1043478, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1090909, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1142857, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1200000, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1263157, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1333333, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1411764, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(1500000, 8, 1, UsbSerialPort.PARITY_NONE);
+            try {
+                usbParameters((int)(2000000/1.04), 8, 1, UsbSerialPort.PARITY_NONE);
+                fail("baud rate error expected");
+            } catch (IOException ignored) {
+            }
+            usbParameters((int)(2000000/1.03), 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(2000000, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters((int)(2000000*1.03), 8, 1, UsbSerialPort.PARITY_NONE);
+            try {
+                usbParameters((int)(2000000*1.04), 8, 1, UsbSerialPort.PARITY_NONE);
+                fail("baud rate error expected");
+            } catch (IOException ignored) {
+            }
+            usbParameters(2000000, 8, 1, UsbSerialPort.PARITY_NONE);
+            usbParameters(3000000, 8, 1, UsbSerialPort.PARITY_NONE);
+            try {
+                usbParameters(4000000, 8, 1, UsbSerialPort.PARITY_NONE);
+                fail("baud rate to high expected");
+            } catch (IOException ignored) {
+            }
+        }
         { // non matching baud rate
             telnet.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);
             usb.setParameters(2400, 8, 1, UsbSerialPort.PARITY_NONE);
@@ -1366,8 +1404,6 @@ public class DeviceTest {
         // control lines retained over close+open
         boolean inputRetained = inputLinesConnected;
         boolean outputRetained = true;
-        if(usb.serialDriver instanceof FtdiSerialDriver)
-            outputRetained = false; // todo
         usb.close(EnumSet.of(UsbWrapper.OpenCloseFlags.NO_CONTROL_LINE_INIT));
         usb.open(EnumSet.of(UsbWrapper.OpenCloseFlags.NO_CONTROL_LINE_INIT, UsbWrapper.OpenCloseFlags.NO_IOMANAGER_THREAD));
         usb.setParameters(19200, 8, 1, UsbSerialPort.PARITY_NONE);

usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/FtdiSerialDriver.java

@@ -1,5 +1,6 @@
 /* Copyright 2011-2013 Google Inc.
  * Copyright 2013 mike wakerly <opensource@hoho.com>
+ * Copyright 2020 kai morich <mail@kai-morich.de>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -33,73 +34,22 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
-/**
+/*
- * A {@link CommonUsbSerialPort} implementation for a variety of FTDI devices
+ * driver is implemented from various information scattered over FTDI documentation
- * <p>
- * This driver is based on <a
- * href="http://www.intra2net.com/en/developer/libftdi">libftdi</a>, and is
- * copyright and subject to the following terms:
  *
- * <pre>
+ * baud rate calculation https://www.ftdichip.com/Support/Documents/AppNotes/AN232B-05_BaudRates.pdf
- *   Copyright (C) 2003 by Intra2net AG
+ * control bits https://www.ftdichip.com/Firmware/Precompiled/UM_VinculumFirmware_V205.pdf
+ * device type https://www.ftdichip.com/Support/Documents/AppNotes/AN_233_Java_D2XX_for_Android_API_User_Manual.pdf -> bvdDevice
  *
- *   This program is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU Lesser General Public License
- *   version 2.1 as published by the Free Software Foundation;
- *
- *   opensource@intra2net.com
- *   http://www.intra2net.com/en/developer/libftdi
- * </pre>
- *
- * </p>
- * <p>
- * Some FTDI devices have not been tested; see later listing of supported and
- * unsupported devices. Devices listed as "supported" support the following
- * features:
- * <ul>
- * <li>Read and write of serial data (see
- * {@link CommonUsbSerialPort#read(byte[], int)} and
- * {@link CommonUsbSerialPort#write(byte[], int)}.</li>
- * <li>Setting serial line parameters (see
- * {@link CommonUsbSerialPort#setParameters(int, int, int, int)}.</li>
- * </ul>
- * </p>
- * <p>
- * Supported and tested devices:
- * <ul>
- * <li>{@value DeviceType#TYPE_R}</li>
- * <li>{@value DeviceType#TYPE_2232H}</li>
- * <li>{@value DeviceType#TYPE_4232H}</li>
- * </ul>
- * </p>
- * <p>
- * Unsupported but possibly working devices (please contact the author with
- * feedback or patches):
- * <ul>
- * <li>{@value DeviceType#TYPE_2232C}</li>
- * <li>{@value DeviceType#TYPE_AM}</li>
- * <li>{@value DeviceType#TYPE_BM}</li>
- * </ul>
- * </p>
- *
- * @author mike wakerly (opensource@hoho.com)
- * @see <a href="https://github.com/mik3y/usb-serial-for-android">USB Serial
- *      for Android project page</a>
- * @see <a href="http://www.ftdichip.com/">FTDI Homepage</a>
- * @see <a href="http://www.intra2net.com/en/developer/libftdi">libftdi</a>
  */
+
 public class FtdiSerialDriver implements UsbSerialDriver {
 
+    private static final String TAG = FtdiSerialPort.class.getSimpleName();
+
     private final UsbDevice mDevice;
     private final List<UsbSerialPort> mPorts;
 
-    /**
-     * FTDI chip types.
-     */
-    private static enum DeviceType {
-        TYPE_BM, TYPE_AM, TYPE_2232C, TYPE_R, TYPE_2232H, TYPE_4232H;
-    }
-
     public FtdiSerialDriver(UsbDevice device) {
         mDevice = device;
         mPorts = new ArrayList<>();
@@ -120,96 +70,35 @@ public class FtdiSerialDriver implements UsbSerialDriver {
 
     public class FtdiSerialPort extends CommonUsbSerialPort {
 
-        private static final int USB_TYPE_STANDARD = 0x00 << 5;
-        private static final int USB_TYPE_CLASS = 0x00 << 5;
-        private static final int USB_TYPE_VENDOR = 0x00 << 5;
-        private static final int USB_TYPE_RESERVED = 0x00 << 5;
-
-        private static final int USB_RECIP_DEVICE = 0x00;
-        private static final int USB_RECIP_INTERFACE = 0x01;
-        private static final int USB_RECIP_ENDPOINT = 0x02;
-        private static final int USB_RECIP_OTHER = 0x03;
-
-        private static final int USB_ENDPOINT_IN = 0x80;
-        private static final int USB_ENDPOINT_OUT = 0x00;
-
         private static final int USB_WRITE_TIMEOUT_MILLIS = 5000;
-        private static final int USB_READ_TIMEOUT_MILLIS = 5000;
+        private static final int READ_HEADER_LENGTH = 2; // contains MODEM_STATUS
 
-        // From ftdi.h
+        private static final int REQTYPE_HOST_TO_DEVICE = UsbConstants.USB_TYPE_VENDOR | UsbConstants.USB_DIR_OUT;
-        /**
+        private static final int REQTYPE_DEVICE_TO_HOST = UsbConstants.USB_TYPE_VENDOR | UsbConstants.USB_DIR_IN;
-         * Reset the port.
-         */
-        private static final int SIO_RESET_REQUEST = 0;
 
-        /**
+        private static final int RESET_REQUEST = 0;
-         * Set the modem control register.
+        private static final int MODEM_CONTROL_REQUEST = 1;
-         */
+        private static final int SET_BAUD_RATE_REQUEST = 3;
-        private static final int SIO_MODEM_CTRL_REQUEST = 1;
+        private static final int SET_DATA_REQUEST = 4;
+        private static final int GET_MODEM_STATUS_REQUEST = 5;
+        private static final int SET_LATENCY_TIMER_REQUEST = 9;
+        private static final int GET_LATENCY_TIMER_REQUEST = 10;
 
-        /**
+        private static final int MODEM_CONTROL_DTR_ENABLE = 0x0101;
-         * Set flow control register.
+        private static final int MODEM_CONTROL_DTR_DISABLE = 0x0100;
-         */
+        private static final int MODEM_CONTROL_RTS_ENABLE = 0x0202;
-        private static final int SIO_SET_FLOW_CTRL_REQUEST = 2;
+        private static final int MODEM_CONTROL_RTS_DISABLE = 0x0200;
+        private static final int MODEM_STATUS_CTS = 0x10;
+        private static final int MODEM_STATUS_DSR = 0x20;
+        private static final int MODEM_STATUS_RI = 0x40;
+        private static final int MODEM_STATUS_CD = 0x80;
+        private static final int RESET_ALL = 0;
+        private static final int RESET_PURGE_RX = 1;
+        private static final int RESET_PURGE_TX = 2;
 
-        private static final int SIO_SET_DTR_HIGH = 0x0101;
+        private boolean baudRateWithPort = false;
-        private static final int SIO_SET_DTR_LOW = 0x0100;
+        private boolean dtr = false;
-        private static final int SIO_SET_RTS_HIGH = 0x0202;
+        private boolean rts = false;
-        private static final int SIO_SET_RTS_LOW = 0x0200;
-
-        /**
-         * Set baud rate.
-         */
-        private static final int SIO_SET_BAUD_RATE_REQUEST = 3;
-
-        /**
-         * Set the data characteristics of the port.
-         */
-        private static final int SIO_SET_DATA_REQUEST = 4;
-
-        private static final int SIO_RESET_SIO = 0;
-        private static final int SIO_RESET_PURGE_RX = 1; // RX @ FTDI device = write @ usb-serial-for-android library
-        private static final int SIO_RESET_PURGE_TX = 2;
-
-        /**
-         * Get modem status.
-         */
-        private static final int SIO_GET_MODEM_STATUS_REQUEST = 5;
-
-        private static final int SIO_MODEM_STATUS_CTS = 0x10;
-        private static final int SIO_MODEM_STATUS_DSR = 0x20;
-        private static final int SIO_MODEM_STATUS_RI = 0x40;
-        private static final int SIO_MODEM_STATUS_RLSD = 0x80;
-
-        /**
-         * Set the latency timer.
-         */
-        private static final int SIO_SET_LATENCY_TIMER_REQUEST = 9;
-
-        /**
-         * Get the latency timer.
-         */
-        private static final int SIO_GET_LATENCY_TIMER_REQUEST = 10;
-
-        private static final int FTDI_DEVICE_OUT_REQTYPE =
-                UsbConstants.USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_OUT;
-
-        private static final int FTDI_DEVICE_IN_REQTYPE =
-                UsbConstants.USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN;
-
-        /**
-         * Length of the modem status header, transmitted with every read.
-         */
-        private static final int MODEM_STATUS_HEADER_LENGTH = 2;
-
-        private final String TAG = FtdiSerialDriver.class.getSimpleName();
-
-        private DeviceType mType;
-
-        private int mIndex = 0;
-
-        private boolean mDtrState = false;
-        private boolean mRtsState = false;
 
         public FtdiSerialPort(UsbDevice device, int portNumber) {
             super(device, portNumber);
@@ -220,95 +109,38 @@ public class FtdiSerialDriver implements UsbSerialDriver {
             return FtdiSerialDriver.this;
         }
 
-        /**
-         * Filter FTDI status bytes from buffer
-         * @param buffer The source buffer (which contains status bytes)
-         *        buffer The destination buffer to write the status bytes into (can be src)
-         * @param totalBytesRead Number of bytes read to src
-         * @return The number of payload bytes
-         */
-        @Override
-        protected int readFilter(byte[] buffer, int totalBytesRead) throws IOException {
-            if (totalBytesRead < MODEM_STATUS_HEADER_LENGTH) {
-                throw new IOException("Expected at least " + MODEM_STATUS_HEADER_LENGTH + " bytes");
-            }
-            int maxPacketSize = mReadEndpoint.getMaxPacketSize();
-            final int packetsCount = (totalBytesRead + maxPacketSize -1 )/ maxPacketSize;
-            for (int packetIdx = 0; packetIdx < packetsCount; ++packetIdx) {
-                final int count = (packetIdx == (packetsCount - 1))
-                        ? totalBytesRead - packetIdx * maxPacketSize - MODEM_STATUS_HEADER_LENGTH
-                        : maxPacketSize - MODEM_STATUS_HEADER_LENGTH;
-                if (count > 0) {
-                    System.arraycopy(buffer, packetIdx * maxPacketSize + MODEM_STATUS_HEADER_LENGTH,
-                                     buffer, packetIdx * (maxPacketSize - MODEM_STATUS_HEADER_LENGTH),
-                                     count);
-                }
-            }
-            return totalBytesRead - (packetsCount * 2);
-        }
-
-        private void reset() throws IOException {
-            // TODO(mikey): autodetect.
-            mType = DeviceType.TYPE_R;
-            if(mDevice.getInterfaceCount() > 1) {
-                mIndex = mPortNumber + 1;
-                if (mDevice.getInterfaceCount() == 2)
-                    mType = DeviceType.TYPE_2232H;
-                if (mDevice.getInterfaceCount() == 4)
-                    mType = DeviceType.TYPE_4232H;
-            }
-
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_RESET_REQUEST,
-                    SIO_RESET_SIO, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
-            if (result != 0) {
-                throw new IOException("Reset failed: result=" + result);
-            }
-            mDtrState = false;
-            mRtsState = false;
-        }
-
-        public void setLatencyTimer(int latencyTime) throws IOException {
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_SET_LATENCY_TIMER_REQUEST,
-                    latencyTime, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
-            if (result != 0) {
-                throw new IOException("Set latency timer failed: result=" + result);
-            }
-        }
-
-        public int getLatencyTimer() throws IOException {
-            byte[] data = new byte[1];
-            int result = mConnection.controlTransfer(FTDI_DEVICE_IN_REQTYPE, SIO_GET_LATENCY_TIMER_REQUEST,
-                    0, mIndex, data, data.length, USB_WRITE_TIMEOUT_MILLIS);
-            if (result != 1) {
-                throw new IOException("Get latency timer failed: result=" + result);
-            }
-            return data[0];
-        }
-
-        private int getModemStatus() throws IOException {
-            byte[] data = new byte[2];
-            int result = mConnection.controlTransfer(FTDI_DEVICE_IN_REQTYPE, SIO_GET_MODEM_STATUS_REQUEST,
-                    0, mIndex, data, data.length, USB_WRITE_TIMEOUT_MILLIS);
-            if (result != 2) {
-                throw new IOException("Get modem statusfailed: result=" + result);
-            }
-            return data[0];
-        }
 
         @Override
         protected void openInt(UsbDeviceConnection connection) throws IOException {
-            if (connection.claimInterface(mDevice.getInterface(mPortNumber), true)) {
+            if (!connection.claimInterface(mDevice.getInterface(mPortNumber), true)) {
-                Log.d(TAG, "claimInterface " + mPortNumber + " SUCCESS");
+                throw new IOException("Could not claim interface " + mPortNumber);
-            } else {
-                throw new IOException("Error claiming interface " + mPortNumber);
             }
             if (mDevice.getInterface(mPortNumber).getEndpointCount() < 2) {
-                throw new IOException("Insufficient number of endpoints (" +
+                throw new IOException("Not enough endpoints");
-                        mDevice.getInterface(mPortNumber).getEndpointCount() + ")");
             }
             mReadEndpoint = mDevice.getInterface(mPortNumber).getEndpoint(0);
             mWriteEndpoint = mDevice.getInterface(mPortNumber).getEndpoint(1);
-            reset();
+
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, RESET_REQUEST,
+                    RESET_ALL, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+            if (result != 0) {
+                throw new IOException("Reset failed: result=" + result);
+            }
+            result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, MODEM_CONTROL_REQUEST,
+                    (dtr ? MODEM_CONTROL_DTR_ENABLE : MODEM_CONTROL_DTR_DISABLE) |
+                            (rts ? MODEM_CONTROL_RTS_ENABLE : MODEM_CONTROL_RTS_DISABLE),
+                    mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+            if (result != 0) {
+                throw new IOException("Init RTS,DTR failed: result=" + result);
+            }
+
+            // mDevice.getVersion() would require API 23
+            byte[] rawDescriptors = connection.getRawDescriptors();
+            if(rawDescriptors == null || rawDescriptors.length < 14) {
+                throw new IOException("Could not get device descriptors");
+            }
+            int deviceType = rawDescriptors[13];
+            baudRateWithPort = deviceType == 7 || deviceType == 8 || deviceType == 9; // ...H devices
         }
 
         @Override
@@ -318,18 +150,69 @@ public class FtdiSerialDriver implements UsbSerialDriver {
             } catch(Exception ignored) {}
         }
 
-        private int setBaudRate(int baudRate) throws IOException {
+        @Override
-            long[] vals = convertBaudrate(baudRate);
+        protected int readFilter(byte[] buffer, int totalBytesRead) throws IOException {
-            long actualBaudrate = vals[0];
+            final int maxPacketSize = mReadEndpoint.getMaxPacketSize();
-            long index = vals[1];
+            int destPos = 0;
-            long value = vals[2];
+            for(int srcPos = 0; srcPos < totalBytesRead; srcPos += maxPacketSize) {
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE,
+                int length = Math.min(srcPos + maxPacketSize, totalBytesRead) - (srcPos + READ_HEADER_LENGTH);
-                    SIO_SET_BAUD_RATE_REQUEST, (int) value, (int) index,
+                if (length < 0)
-                    null, 0, USB_WRITE_TIMEOUT_MILLIS);
+                    throw new IOException("Expected at least " + READ_HEADER_LENGTH + " bytes");
+                System.arraycopy(buffer, srcPos + READ_HEADER_LENGTH, buffer, destPos, length);
+                destPos += length;
+            }
+            return destPos;
+        }
+
+        private void setBaudrate(int baudRate) throws IOException {
+            int divisor, subdivisor, effectiveBaudRate;
+            if (baudRate > 3500000) {
+                throw new IOException("Baud rate to high");
+            } else if(baudRate >= 2500000) {
+                divisor = 0;
+                subdivisor = 0;
+                effectiveBaudRate = 3000000;
+            } else if(baudRate >= 1750000) {
+                divisor = 1;
+                subdivisor = 0;
+                effectiveBaudRate = 2000000;
+            } else {
+                divisor = (24000000 << 1) / baudRate;
+                divisor = (divisor + 1) >> 1; // round
+                subdivisor = divisor & 0x07;
+                divisor >>= 3;
+                if (divisor > 0x3fff) // exceeds bit 13 at 183 baud
+                    throw new IOException("Baud rate to low");
+                effectiveBaudRate = (24000000 << 1) / ((divisor << 3) + subdivisor);
+                effectiveBaudRate = (effectiveBaudRate +1) >> 1;
+            }
+            double baudRateError = Math.abs(1.0 - (effectiveBaudRate / (double)baudRate));
+            if(baudRateError >= 0.031) // can happen only > 1.5Mbaud
+                throw new IOException(String.format("baud rate deviation %.1f%% is higher than allowed 3%%", baudRateError*100));
+            int value = divisor;
+            int index = 0;
+            switch(subdivisor) {
+                case 0:                              break; // 16,15,14 = 000 - sub-integer divisor = 0
+                case 4: value |= 0x4000;             break; // 16,15,14 = 001 - sub-integer divisor = 0.5
+                case 2: value |= 0x8000;             break; // 16,15,14 = 010 - sub-integer divisor = 0.25
+                case 1: value |= 0xc000;             break; // 16,15,14 = 011 - sub-integer divisor = 0.125
+                case 3: value |= 0x0000; index |= 1; break; // 16,15,14 = 100 - sub-integer divisor = 0.375
+                case 5: value |= 0x4000; index |= 1; break; // 16,15,14 = 101 - sub-integer divisor = 0.625
+                case 6: value |= 0x8000; index |= 1; break; // 16,15,14 = 110 - sub-integer divisor = 0.75
+                case 7: value |= 0xc000; index |= 1; break; // 16,15,14 = 111 - sub-integer divisor = 0.875
+            }
+            if(baudRateWithPort) {
+                index <<= 8;
+                index |= mPortNumber+1;
+            }
+            Log.d(TAG, String.format("baud rate=%d, effective=%d, error=%.1f%%, value=0x%04x, index=0x%04x, divisor=%d, subdivisor=%d",
+                    baudRate, effectiveBaudRate, baudRateError*100, value, index, divisor, subdivisor));
+
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, SET_BAUD_RATE_REQUEST,
+                    value, index, null, 0, USB_WRITE_TIMEOUT_MILLIS);
             if (result != 0) {
                 throw new IOException("Setting baudrate failed: result=" + result);
             }
-            return (int) actualBaudrate;
         }
 
         @Override
@@ -337,7 +220,7 @@ public class FtdiSerialDriver implements UsbSerialDriver {
             if(baudRate <= 0) {
                 throw new IllegalArgumentException("Invalid baud rate: " + baudRate);
             }
-            setBaudRate(baudRate);
+            setBaudrate(baudRate);
 
             int config = 0;
             switch (dataBits) {
@@ -354,19 +237,18 @@ public class FtdiSerialDriver implements UsbSerialDriver {
 
             switch (parity) {
                 case PARITY_NONE:
-                    config |= (0x00 << 8);
                     break;
                 case PARITY_ODD:
-                    config |= (0x01 << 8);
+                    config |= 0x100;
                     break;
                 case PARITY_EVEN:
-                    config |= (0x02 << 8);
+                    config |= 0x200;
                     break;
                 case PARITY_MARK:
-                    config |= (0x03 << 8);
+                    config |= 0x300;
                     break;
                 case PARITY_SPACE:
-                    config |= (0x04 << 8);
+                    config |= 0x400;
                     break;
                 default:
                     throw new IllegalArgumentException("Invalid parity: " + parity);
@@ -374,170 +256,93 @@ public class FtdiSerialDriver implements UsbSerialDriver {
 
             switch (stopBits) {
                 case STOPBITS_1:
-                    config |= (0x00 << 11);
                     break;
                 case STOPBITS_1_5:
                     throw new UnsupportedOperationException("Unsupported stop bits: 1.5");
                 case STOPBITS_2:
-                    config |= (0x02 << 11);
+                    config |= 0x1000;
                     break;
                 default:
                     throw new IllegalArgumentException("Invalid stop bits: " + stopBits);
             }
 
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE,
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, SET_DATA_REQUEST,
-                    SIO_SET_DATA_REQUEST, config, mIndex,
+                    config, mPortNumber+1,null, 0, USB_WRITE_TIMEOUT_MILLIS);
-                    null, 0, USB_WRITE_TIMEOUT_MILLIS);
             if (result != 0) {
                 throw new IOException("Setting parameters failed: result=" + result);
             }
         }
 
-        private long[] convertBaudrate(int baudrate) {
+        private int getStatus() throws IOException {
-            // TODO(mikey): Braindead transcription of libfti method.  Clean up,
+            byte[] data = new byte[2];
-            // using more idiomatic Java where possible.
+            int result = mConnection.controlTransfer(REQTYPE_DEVICE_TO_HOST, GET_MODEM_STATUS_REQUEST,
-            int divisor = 24000000 / baudrate;
+                    0, mPortNumber+1, data, data.length, USB_WRITE_TIMEOUT_MILLIS);
-            int bestDivisor = 0;
+            if (result != 2) {
-            int bestBaud = 0;
+                throw new IOException("Get modem status failed: result=" + result);
-            int bestBaudDiff = 0;
-            int fracCode[] = {
-                    0, 3, 2, 4, 1, 5, 6, 7
-            };
-
-            for (int i = 0; i < 2; i++) {
-                int tryDivisor = divisor + i;
-                int baudEstimate;
-                int baudDiff;
-
-                if (tryDivisor <= 8) {
-                    // Round up to minimum supported divisor
-                    tryDivisor = 8;
-                } else if (mType != DeviceType.TYPE_AM && tryDivisor < 12) {
-                    // BM doesn't support divisors 9 through 11 inclusive
-                    tryDivisor = 12;
-                } else if (divisor < 16) {
-                    // AM doesn't support divisors 9 through 15 inclusive
-                    tryDivisor = 16;
-                } else {
-                    if (mType == DeviceType.TYPE_AM) {
-                        // TODO
-                    } else {
-                        if (tryDivisor > 0x1FFFF) {
-                            // Round down to maximum supported divisor value (for
-                            // BM)
-                            tryDivisor = 0x1FFFF;
             }
-                    }
+            return data[0];
-                }
-
-                // Get estimated baud rate (to nearest integer)
-                baudEstimate = (24000000 + (tryDivisor / 2)) / tryDivisor;
-
-                // Get absolute difference from requested baud rate
-                if (baudEstimate < baudrate) {
-                    baudDiff = baudrate - baudEstimate;
-                } else {
-                    baudDiff = baudEstimate - baudrate;
-                }
-
-                if (i == 0 || baudDiff < bestBaudDiff) {
-                    // Closest to requested baud rate so far
-                    bestDivisor = tryDivisor;
-                    bestBaud = baudEstimate;
-                    bestBaudDiff = baudDiff;
-                    if (baudDiff == 0) {
-                        // Spot on! No point trying
-                        break;
-                    }
-                }
-            }
-
-            // Encode the best divisor value
-            long encodedDivisor = (bestDivisor >> 3) | (fracCode[bestDivisor & 7] << 14);
-            // Deal with special cases for encoded value
-            if (encodedDivisor == 1) {
-                encodedDivisor = 0; // 3000000 baud
-            } else if (encodedDivisor == 0x4001) {
-                encodedDivisor = 1; // 2000000 baud (BM only)
-            }
-
-            // Split into "value" and "index" values
-            long value = encodedDivisor & 0xFFFF;
-            long index;
-            if (mType == DeviceType.TYPE_2232C || mType == DeviceType.TYPE_2232H
-                    || mType == DeviceType.TYPE_4232H) {
-                index = (encodedDivisor >> 8) & 0xff00;
-                index |= mIndex;
-            } else {
-                index = (encodedDivisor >> 16) & 0xffff;
-            }
-
-            // Return the nearest baud rate
-            return new long[] {
-                    bestBaud, index, value
-            };
         }
 
         @Override
         public boolean getCD() throws IOException {
-            return (getModemStatus() & SIO_MODEM_STATUS_RLSD) != 0;
+            return (getStatus() & MODEM_STATUS_CD) != 0;
         }
 
         @Override
         public boolean getCTS() throws IOException {
-            return (getModemStatus() & SIO_MODEM_STATUS_CTS) != 0;
+            return (getStatus() & MODEM_STATUS_CTS) != 0;
         }
 
         @Override
         public boolean getDSR() throws IOException {
-            return (getModemStatus() & SIO_MODEM_STATUS_DSR) != 0;
+            return (getStatus() & MODEM_STATUS_DSR) != 0;
         }
 
         @Override
         public boolean getDTR() throws IOException {
-            return mDtrState;
+            return dtr;
         }
 
         @Override
         public void setDTR(boolean value) throws IOException {
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_MODEM_CTRL_REQUEST,
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, MODEM_CONTROL_REQUEST,
-                    value ? SIO_SET_DTR_HIGH : SIO_SET_DTR_LOW, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+                    value ? MODEM_CONTROL_DTR_ENABLE : MODEM_CONTROL_DTR_DISABLE, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
             if (result != 0) {
                 throw new IOException("Set DTR failed: result=" + result);
             }
-            mDtrState = value;
+            dtr = value;
         }
 
         @Override
         public boolean getRI() throws IOException {
-            return (getModemStatus() & SIO_MODEM_STATUS_RI) != 0;
+            return (getStatus() & MODEM_STATUS_RI) != 0;
         }
 
         @Override
         public boolean getRTS() throws IOException {
-            return mRtsState;
+            return rts;
         }
 
         @Override
         public void setRTS(boolean value) throws IOException {
-            int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_MODEM_CTRL_REQUEST,
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, MODEM_CONTROL_REQUEST,
-                    value ? SIO_SET_RTS_HIGH : SIO_SET_RTS_LOW, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+                    value ? MODEM_CONTROL_RTS_ENABLE : MODEM_CONTROL_RTS_DISABLE, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
             if (result != 0) {
                 throw new IOException("Set DTR failed: result=" + result);
             }
-            mRtsState = value;
+            rts = value;
         }
 
         @Override
         public EnumSet<ControlLine> getControlLines() throws IOException {
-            int status = getModemStatus();
+            int status = getStatus();
             EnumSet<ControlLine> set = EnumSet.noneOf(ControlLine.class);
-            if(mRtsState) set.add(ControlLine.RTS);
+            if(rts) set.add(ControlLine.RTS);
-            if((status & SIO_MODEM_STATUS_CTS) != 0) set.add(ControlLine.CTS);
+            if((status & MODEM_STATUS_CTS) != 0) set.add(ControlLine.CTS);
-            if(mDtrState) set.add(ControlLine.DTR);
+            if(dtr) set.add(ControlLine.DTR);
-            if((status & SIO_MODEM_STATUS_DSR) != 0) set.add(ControlLine.DSR);
+            if((status & MODEM_STATUS_DSR) != 0) set.add(ControlLine.DSR);
-            if((status & SIO_MODEM_STATUS_RLSD) != 0) set.add(ControlLine.CD);
+            if((status & MODEM_STATUS_CD) != 0) set.add(ControlLine.CD);
-            if((status & SIO_MODEM_STATUS_RI) != 0) set.add(ControlLine.RI);
+            if((status & MODEM_STATUS_RI) != 0) set.add(ControlLine.RI);
             return set;
         }
 
@@ -549,22 +354,41 @@ public class FtdiSerialDriver implements UsbSerialDriver {
         @Override
         public boolean purgeHwBuffers(boolean purgeWriteBuffers, boolean purgeReadBuffers) throws IOException {
             if (purgeWriteBuffers) {
-                int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_RESET_REQUEST,
+                int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, RESET_REQUEST,
-                        SIO_RESET_PURGE_RX, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+                        RESET_PURGE_RX, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
                 if (result != 0) {
                     throw new IOException("purge write buffer failed: result=" + result);
                 }
             }
 
             if (purgeReadBuffers) {
-                int result = mConnection.controlTransfer(FTDI_DEVICE_OUT_REQTYPE, SIO_RESET_REQUEST,
+                int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, RESET_REQUEST,
-                        SIO_RESET_PURGE_TX, mIndex, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+                        RESET_PURGE_TX, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
                 if (result != 0) {
                     throw new IOException("purge read buffer failed: result=" + result);
                 }
             }
             return true;
         }
+
+        public void setLatencyTimer(int latencyTime) throws IOException {
+            int result = mConnection.controlTransfer(REQTYPE_HOST_TO_DEVICE, SET_LATENCY_TIMER_REQUEST,
+                    latencyTime, mPortNumber+1, null, 0, USB_WRITE_TIMEOUT_MILLIS);
+            if (result != 0) {
+                throw new IOException("Set latency timer failed: result=" + result);
+            }
+        }
+
+        public int getLatencyTimer() throws IOException {
+            byte[] data = new byte[1];
+            int result = mConnection.controlTransfer(REQTYPE_DEVICE_TO_HOST, GET_LATENCY_TIMER_REQUEST,
+                    0, mPortNumber+1, data, data.length, USB_WRITE_TIMEOUT_MILLIS);
+            if (result != 1) {
+                throw new IOException("Get latency timer failed: result=" + result);
+            }
+            return data[0];
+        }
+
     }
 
     public static Map<Integer, int[]> getSupportedDevices() {
@@ -575,7 +399,6 @@ public class FtdiSerialDriver implements UsbSerialDriver {
                     UsbId.FTDI_FT232H,
                     UsbId.FTDI_FT2232H,
                     UsbId.FTDI_FT4232H,
-                    UsbId.FTDI_FT231X,
                 });
         return supportedDevices;
     }

usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/UsbId.java

@@ -36,7 +36,6 @@ public final class UsbId {
     public static final int FTDI_FT2232H = 0x6010;
     public static final int FTDI_FT4232H = 0x6011;
     public static final int FTDI_FT232H = 0x6014;
-    public static final int FTDI_FT231X = 0x6015;
 
     public static final int VENDOR_ATMEL = 0x03EB;
     public static final int ATMEL_LUFA_CDC_DEMO_APP = 0x2044;