Message-ID: <490C4133.30400@shikadi.net>
Date: Sat, 01 Nov 2008 21:44:51 +1000
From: Adam Nielsen <a.nielsen@shikadi.net>
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Subject: Can you use the USB HID interface within a driver?
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Hi all,

I'm about to start writing a driver for a Gigabyte Odin PC power supply. 
  This device has a USB connection which allows you to monitor 
temperature, voltages, current, etc.

Before I start coding the USB side of things, I'd just like some advice 
as to the best way of communicating with the device.

I would rather write the driver in kernel space (so that it "just works" 
and provides a hwmon interface without installing extra software), 
however the device already appears to the system as a USB HID device, 
and so gets claimed by the existing usbhid driver.

Is there any way to interface with the HID driver from within another 
driver?  Or will I have to claim the device first (or disconnect 
usbhid), and communicate with it myself?

I've tried to find some example code from a driver that already does 
this (such as a USB keyboard driver) but I'm having some trouble finding 
one!  The closest drivers I can find are all the ones in 
drivers/hid/usbhid, but they all seem to be "embedded" in hid-core.c. 
Does that mean I need to modify hid-core.c to call my driver?

Or perhaps someone could point me in the direction of a USB HID driver 
that does things "properly" already?

Many thanks,
Adam.
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