writing usb drivers under 8.x

Jim Bryant kc5vdj.freebsd at gmail.com
Thu Aug 26 17:59:24 UTC 2010


i have some usb devices, in the hid class, that i am wanting to write 
some drivers for.

seeing that one of these previously had an older non-submitted driver 
for 5.x-7.x online, i thought that might be a good starting point (the 
imon vfd/lirc driver), but that does not work, due to the changes in the 
usb subsystem.

where can i find documentation on this subsystem?

are there any decent skeletons to start with, or does this need to be 
from scratch?

i'd like to start with a driver for the pcsensor temper usb thermometer, 
for which i already wrote a libusb util for, since these are widely 
sold, and very popular (and usually around $5 USD), and since it only 
has one transaction (read current temp), I figure it would be easier to 
start with while I learn the usb driver framework.

as for the imon vfd unit, i'd like to tackle that next.  i have written 
libusb utilities for all of the display functions supported, and have 
documented the knob/button interrupt packets (only three packet types, 
clockwise, counterclockwise, and button down).  all of the remote 
control functions are well-documented in lirc.

i've been looking through the sources in the sys tree, but would like to 
find some comprehensive documentation of the new usb subsystem, and 
maybe someone who can give me pointers as i go.

jim



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