Add readme and copy of GPLv2

[exar-uart-driver.git] / README.exar

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+Vizzini USB Serial
+==================
+
+Version 1.0, 06/11/2013
+
+The source code is compatible with these kernel versions (and probably others):
+    3.5.0 and newer.
+
+
+Installation
+------------
+
+* Make sure the Vizzini device is unplugged from the Linux host.
+
+* Make sure that the cdc-acm driver and any previously loaded vizzini
+  driver modules are not loaded.
+
+       # rmmod cdc_acm
+       # rmmod vizzini
+       # modprobe -r usbserial
+
+* Install the vizzini driver module.
+
+       # modprobe usbserial
+       # insmod ./vizzini.ko
+
+* Plug Vizzini into the host.  You should see four devices created,
+  typically /dev/ttyUSB[0-3].
+
+
+Operation
+---------
+
+The vizzini driver presents a standard Linux TTY interface that can be
+configured and manipulated with the usual APIs (tcgetattr(),
+tcsetattr(), ioctl(), read(), write(), etc).
+
+The normal supported character modes are 7N1, 7N2, 7P1, 7P2, 8N1, 8N2,
+8P1, 8P2, with odd, even, mark and space parity.
+
+Vizzini also supports 9N1 and 9N2.  It is enabled by using the CS5
+character size.  In this mode a 9-bit character can be written to the
+device with two bytes.  Bits 0..7 of the character are taken from the
+first byte, and bit-8 of the character is taken from bit-0 of the
+second byte.
+
+Similarly, a 9-bit character can be read from the device as a pair of
+bytes.  Bits 0..7 of the character are in the first byte, and bit-8 of
+the character is taken from bit-0 of the second byte.  Bits 1..7 of
+the second byte are undefined.
+