Add a README

Signed-off-by: Andrew 'Necromant' Andrianov <andrew@ncrmnt.org>

diff --git a/README.md b/README.md
new file mode 100644 (file)
index 0000000..a9c0618
--- /dev/null
+++ b/README.md
@@ -0,0 +1,48 @@
+# PL2303 Userspace GPIO control tool
+
+This is a small tool for linux userspace that allows you to interact
+with GPIO lines on PL2303HX devices. 
+It has only been tested on PL2303HXA, but may work for other revisions. 
+Since no common GPIO driver for those exists at the time of writing in
+the linux kernel - this should serve as a placeholder till upstream guys 
+fix that.  
+
+
+## Compiling & installing
+
+You'll need libusb-1.0-dev, gcc and pkg-config. Just run 
+
+make 
+sudo make install
+
+pl2303gpio comes with udev rules that will be dropped into your
+/etc/udev/rules.d/
+Just reload udev after installing it
+
+## Do I have to close minicom / rmmod pl2303 to use this tool ? 
+
+Nope. Just run it in a separate terminal whenever you need it
+
+## Can I chose which of 70 PL2303 devices plugged this will work with?
+
+Nope, you can't. Patches welcome. 
+
+## Using
+
+pl2303gpio --help
+PL2303HXA userspace GPIO control tool
+(c) Andrew 'Necromant' Andrianov 2014, License: GPLv3
+Usage: ./pl2303gpio [action1] [action2] ...
+Options are: 
+         -g/--gpio  n  - select GPIO, n=0, 1
+         -i/--in       - configure GPIO as input
+         -o/--out v    - configure GPIO as output with value v
+         -r/--read v   - Read current GPIO value
+
+Examples: 
+        ./pl2303gpio --gpio=1 --out 1
+        ./pl2303gpio --gpio=0 --out 0 --gpio=1 --in
+
+## License
+
+GPLv3. I'm too lazy to copy all the text here. Google for it.
\ No newline at end of file