writing usb drivers under 8.x

[Hans Petter Selasky]

On Thursday 26 August 2010 19:59:18 Jim Bryant wrote:
> 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

Hi,

Feel free to post patches here.

Some choices you have:

Use libusb v1.0 or v0.1 if you need portability.

Else use libusb v2.0.

All three versions are contained in -lusb on FreeBSD 8+.

Sylvestre Gallon had some libusb examples in his USB P4 repositorium. Else if 
you have questions regarding libusb you can ask either here or at:

libusb-devel at lists.sourceforge.net

--HPS