Device Nodes under /proc/bus/usb

[Mani]

Hi :

I am using the TI ZOOM2 board running the Android OS . I have written
a application ( similar to vold ) , which listens for UEVENTS and then
dump the UEVENT Packet ( to a Log file ) , when the message related to
a particular USB device is received .

The UEVENT packet indicates that the Kernel created a Device under /
proc/bus/usb/001/003 , however, I am not able to see the Device node
in this Path .

[UEVENT] Sq: 882 S: usb A: 0 P: /devices/platform/musb_hdrc/
usb1/1-1/1-1.4
DEVPATH=/devices/platform/musb_hdrc/usb1/1-1/1-1.4
MAJOR=189
MINOR=2
DEVTYPE=usb_device
DEVICE=/proc/bus/usb/001/003
TYPE=255/255/255
BUSNUM=001
DEVNUM=003

I connected a Dell USB Keyboard , even in this case , i could not find
the Device node under /proc/bus/usb , even though UEVENT indicates
that the Kernel has Created it .

Can someone please let me know, if this is a known issue ? Is it
possible that Device node is created somewhere else ? if so , why
would UEVENT packet indicate , it is under /proc/bus/usb

Thanks
Mani

[Greg KH]

On Tue, Jun 8, 2010 at 8:26 AM, Mani <mani.o...@gmail.com> wrote:
> Hi :
>
> I am using the TI ZOOM2 board running the Android OS . I have written
> a application ( similar to vold ) , which listens for UEVENTS and then
> dump the UEVENT Packet ( to a Log file ) , when the message related to
> a particular USB device is received .
>
> The UEVENT packet indicates that the Kernel created a Device under /
> proc/bus/usb/001/003 , however, I am not able to see the Device node
> in this Path .

That is not a device node, that is a file from the old usbfs.
Just disable that option in your kernel, you don't want it unless you
are using libusb
or writing to usbfs to control the USB device directly.

And if you do want to see it, just mount the file system and you will:
mount -t usbfs none /proc/bus/usb

But again, you really don't want this, it's old and doesn't work for
multi-user machines.

And also, it's not a device node, it is a device "file" that
corresponds to the USB device.
Not what you are thinking of when you think of a "device node" in the
Unix sense.

hope this helps,

greg k-h

[Burhan Eyuboglu]

I'm using libusb, however I have a problem with the permission on opening the dev/bus/usb/*/*. You said /proc/bus/usb is the location, however I'm new in Android and I don't know where is the device file in system files on Android and how can libusb functions (which are native c codes which is compiled with ndk) reach those device files?

9 Haziran 2010 Çarşamba 21:16:25 UTC+3 tarihinde Greg KH yazdı: