On Tue, 29 Mar 2005, Johannes Berg wrote:
> On Tue, 2005-03-29 at 12:08 -0500, jklaas wrote:
> > Being a usb gadget freak, I bought this combo mouse and usb controlled
> > FM Radio for cheap ($10 + shipping). It looks really neat, and I pretty
> > much figured out how to get the radio to work.
>
> Neat.
>
> > I was wondering if there was any way to get multiple drivers talking to
> > the same device. Or, alternatively, can I write a libusb program that
> > will talk to the radio while the mouse has been grabbed by the HID
> > driver.
>
> You can bind drivers to specific endpoints. I would guess that the
> usbhid driver only grabs the endpoint that is HID, and leaves one free.
> Check the output of cat /proc/bus/usb/devices you should see something
> like I have here:
> T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 4 Spd=12 MxCh= 0
> D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
> P: Vendor=05ac ProdID=020e Rev= 0.28
> S: Manufacturer=Apple Computer
> S: Product=Apple Internal Keyboard/Trackpad
> C:* #Ifs= 3 Cfg#= 1 Atr=a0 MxPwr= 40mA
> I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=01 Driver=usbhid
> E: Ad=83(I) Atr=03(Int.) MxPS= 8 Ivl=10ms
> I: If#= 1 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=AppleTrackpad
> E: Ad=81(I) Atr=03(Int.) MxPS= 32 Ivl=1ms
> I: If#= 2 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=00 Prot=00 Driver=usbhid
> E: Ad=84(I) Atr=03(Int.) MxPS= 1 Ivl=10ms
>
> Except "Driver=(none)" for the radio.
>
> There, I have a single device with 3 endpoints and 2 drivers bound to
> them. The source for the AppleTrackpad driver is available from
> http://johannes.sipsolutions.net/PowerBook
> Basically I just went through the same question you did and have the
> answer in there.
>
> johannes
>
Cool, thanks.
I have another question that I don't quite understand. With the FM Radio
the TransferBufferLength in the URB going down is usually either 0x16 or
0xca. The URB coming back has the TransferBufferLength is 0x06. I
guess I don't quite understand why they're different.
--
James Klaas
"Let me tell you something my friend. Hope is a dangerous thing. Hope can
drive a man insane." Ellis Boyd (Red) Redding, from Shawshank Redemption
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