Figuring out USB device locations

Figuring out USB device locations

[James Lamanna]

Is there an easy way to find out what /dev entries usb devices get 
mapped to from userspace? Specifically mice since the /dev location 
isn't even printed in dmesg.
I have a program that needs to open each mouse independently so 
/dev/input/mice isn't an option.

I'm also on a 2.4 kernel so sysfs/udev is not available.

Thanks.
-- 
James Lamanna

Re: Figuring out USB device locations

[Greg KH]

On Thu, Mar 25, 2004 at 09:20:47AM -0800, James Lamanna wrote:
> Is there an easy way to find out what /dev entries usb devices get 
> mapped to from userspace?

"easy way" on 2.4?  No, sorry.  You need 2.6 to determine this in a
simple manner.  But there are some files in the /proc/bus/usb/
and /proc/bus/input/ directories that will help you out.

Good luck,

greg k-h

Re: Figuring out USB device locations

[James Lamanna]

Greg KH wrote:

> On Thu, Mar 25, 2004 at 09:20:47AM -0800, James Lamanna wrote:
> 
>>Is there an easy way to find out what /dev entries usb devices get 
>>mapped to from userspace?
> 
> 
> "easy way" on 2.4?  No, sorry.  You need 2.6 to determine this in a
> simple manner.  But there are some files in the /proc/bus/usb/
> and /proc/bus/input/ directories that will help you out.

Hmm...its not obvious to me how i can use /proc/bus/usb/xxx/yyy to get 
the /dev entry information. I can get the USB device number, but I don't 
see how to get at a mapping to a major/minor in /dev space (or is this 
not possible in 2.4)...

-- 
James Lamanna

Re: Figuring out USB device locations

[Greg KH]

On Thu, Mar 25, 2004 at 04:33:06PM -0800, James Lamanna wrote:
> Greg KH wrote:
> 
> >On Thu, Mar 25, 2004 at 09:20:47AM -0800, James Lamanna wrote:
> >
> >>Is there an easy way to find out what /dev entries usb devices get 
> >>mapped to from userspace?
> >
> >
> >"easy way" on 2.4?  No, sorry.  You need 2.6 to determine this in a
> >simple manner.  But there are some files in the /proc/bus/usb/
> >and /proc/bus/input/ directories that will help you out.
> 
> Hmm...its not obvious to me how i can use /proc/bus/usb/xxx/yyy to get 
> the /dev entry information. I can get the USB device number, but I don't 
> see how to get at a mapping to a major/minor in /dev space (or is this 
> not possible in 2.4)...

Well, for mice you can corrispond the usb position found in
/proc/bus/usb/devices with the input information found in
/proc/bus/usb/input to determine which /dev file that mouse is
(possibly, but you might get a close guess there.)

But remember, under 2.4 this is quite difficult.  I suggest just giving
up and using 2.6 :)

thanks,

greg k-h