1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/staging/frontier/README b/drivers/staging/frontier/README
new file mode 100644
index 00000000000..cd07af22406
--- /dev/null
+++ b/drivers/staging/frontier/README
@@ -0,0 +1,47 @@
+This directory contains the Linux USB Tranzport and Alphatrack Kernel drivers.
+
+See http://www.frontierdesign.com for details on these devices.
+
+Userspace test code is available from
+
+git://toutatis.isc.org/home/d/src/git/frontier.git
+
+At present the tranzport does reads/writes of 8 byte cmds to
+/dev/tranzport0 to control the lights, screen, and wheel.
+
+At present the alphatrack accepts reads/writes of 12 byte cmds to
+/dev/tranzport0 to control the lights, screen, fader and touchpad.
+
+The tranzport driver provides a rudimentary sysfs interface for the status of
+the device and a writable parameter for turning wheel compression on and off.
+
+The API is nothing more than the USB commands issued to the device. Why?
+
+The control wheel/fader can generate events far too quickly for
+a typical userspace application to keep up with them via libusb. Input
+needs to be 100% accurate and fast in order for the alphatrack or tranzport
+to be useful.
+
+UIO would be useful except that usb disconnect events need
+to be handled correctly.
+
+A sysfs interface is perfect for simple userspace apps to do fun things with
+the lights and screen. But it's fairly lousy for handling input events and
+very lousy for watching the state of the shuttle wheel.
+
+A linux input events interface is great for the input events and shuttle wheel.
+* It's theoretically OK on LEDs.
+* A fader can be mapped to an absolute mouse device.
+* But there is no LCD support at all, or fader feedback support in that API
+
+So, thus, these stubby drivers exist.
+
+In the end this could be driven by a midi layer, which handles all those
+cases via a well defined API, but - among other things - is slow, doesn't do
+flow control, and is a LOT of extra work, none of which is required at
+the kernel level (probably). Frankly, I'd like to keep the
+core driver simple because the only realtime work really required is
+the bottom half interrupt handler and the output overlapping.
+
+Exposing some sort of clean api to userspace would be perfect. What that
+API looks like? Gah. beats me.