package com.ftdi.usb;
import java.io.*;
+/**
+ * A Java wrapper around libftdi.
+ *
+ * Note: blocking reads are currently implemented by busy-waiting.
+ * This is really ugly. Check the linux kernel source to see how to
+ * get libftdi to do it properly.
+ *
+ * Flow control is also not properly supported.
+ */
public class FtdiUart {
- protected int bits = 0;
- protected SWIGTYPE_p_ftdi_context context = example.new_ftdi_context();
+ private SWIGTYPE_p_ftdi_context context = example.new_ftdi_context();
public OutputStream getOutputStream() { return out; }
public InputStream getInputStream() { return in; }
- public FtdiUart(int vendor, int product) {
+ public FtdiUart(int vendor, int product, int baud) throws IOException {
example.ftdi_init(context);
example.ftdi_usb_open(context, vendor, product);
example.ftdi_usb_reset(context);
- example.ftdi_set_baudrate(context, 1500 * 1000);
+ example.ftdi_set_baudrate(context, baud);
example.ftdi_set_line_property(context, 8, 0, 0);
purge();
}
- public synchronized int readPins() {
- flush();
- byte[] b = new byte[1];
- example.ftdi_read_pins(context, b);
- return b[0];
+ /**
+ * Switch to uart mode, with read/write access to four CBUS lines.
+ * This function is used to write to the CBUS lines (re-invoke it to change their state).
+ * I think readPins() is used to read from them, but I'm not sure.
+ *
+ * @param cbus_mask a four-bit mask; set bit=1 to write to a CBUS line, bit=0 to read from it
+ * @param cbus_bits a four-bit mask; the bits to assert on the write-enabled CBUS lines
+ */
+ public synchronized void uart_and_cbus_mode(int cbus_mask, int cbus_bits) throws IOException {
+ example.ftdi_set_bitmode(context, (short)((cbus_mask << 4) | cbus_bits), (short)0x20);
}
- public void flush() {
- try {
- getOutputStream().flush();
- } catch (Exception e) { throw new RuntimeException(e); }
+ /**
+ * Switch to dbus mode; CBUS lines will be released (ie they will float).
+ * Use getInputStream()/getOutputStream() to read/write the eight DBUS lines.
+ *
+ * @param dbus_mask an eight-bit mask; set bit=1 to write to a DBUS line, bit=0 to read from it
+ */
+ public synchronized void dbus_mode(int dbus_mask) throws IOException {
+ example.ftdi_set_bitmode(context, (short)dbus_mask, (short)0x01);
}
- protected static int mask =
- (1<<0) |
- (1<<1)// |
- //(1<<2) |
- //(1<<3)
- ;
-
- public synchronized void purge() {
- example.ftdi_usb_purge_buffers(context);
- }
- public synchronized void uart(int mask, int bits) {
- example.ftdi_set_bitmode(context, (short)((mask << 4) | bits), (short)0x20);
- //example.ftdi_setflowctrl(context, (1 << 8));
- }
- public synchronized void dbangmode(int dmask) {
- example.ftdi_set_bitmode(context, (short)dmask, (short)0x01);
+ /** returns the instantaneous value present on the DBUS pins */
+ public synchronized int readPins() throws IOException {
+ getOutputStream().flush();
+ byte[] b = new byte[1];
+ example.ftdi_read_pins(context, b);
+ return b[0];
}
- protected int dbits = 0;
-
- protected synchronized void dbang(int bit, boolean val) {
- dbits = val ? (dbits | (1 << bit)) : (dbits & (~(1 << bit)));
- try {
- out.write((byte)dbits);
- } catch (IOException e) { throw new RuntimeException(e); }
+ /** purge the on-chip buffers */
+ public synchronized void purge() throws IOException {
+ example.ftdi_usb_purge_buffers(context);
}
-
private final InputStream in = new InputStream() {
public int available() throws IOException {
// FIXME