USB HID plug and play, hardware developer frustration

USB HID plug and play, hardware developer frustration

[Robin Theunis]

Hi Devs,

Currently I am design a USB product, and in that process I also look
if almost every OS supports my device.
The device is just only a HID digitizer or touch tablet thingy. It
reports it self also as HID device. This is to have it
work PLUG and PLAY. But I gotten a cold shower when trying this on my
linux pcs. It doesn't work!
I did some investigation and found that the linux (kernel) only
support mouses and keyboard, all the other usage pages
that are included in the USB HID specs aren't implemented.
http://www.usb.org/developers/devclass_docs/Hut1_11.pdf

Is there a reason why they aren't implemented? especially the
digitizer thingies because of all the new tablets? Is it difficult
to make a driver to support my device? I have seen that there are a
lot of wacom drivers, I think doing all the same thing.

Thanks a lot,

Robin Theunis

Re: USB HID plug and play, hardware developer frustration

[Dmitry Torokhov]

Ho Robin,

On Sat, Jan 29, 2011 at 09:15:11AM +0100, Robin Theunis wrote:
> Hi Devs,
> 
> Currently I am design a USB product, and in that process I also look
> if almost every OS supports my device.
> The device is just only a HID digitizer or touch tablet thingy. It
> reports it self also as HID device. This is to have it
> work PLUG and PLAY. But I gotten a cold shower when trying this on my
> linux pcs. It doesn't work!
> I did some investigation and found that the linux (kernel) only
> support mouses and keyboard, all the other usage pages
> that are included in the USB HID specs aren't implemented.
> http://www.usb.org/developers/devclass_docs/Hut1_11.pdf
> 
> Is there a reason why they aren't implemented? especially the
> digitizer thingies because of all the new tablets?

Linux HID driver does have code to handle digitizers, please take a look
at drivers/hid/hid-input.c::hidinput_configure_usage().

> Is it difficult
> to make a driver to support my device?

It should not be. You might need to tweak usage mappings a bit by the
way of writing small HID sub-driver. Look for examples in
drivers/hid/hid-<vendor>.c

If you need additional help I'd recommend asking on
linux-input@vger.kernel.org

> I have seen that there are a
> lot of wacom drivers, I think doing all the same thing.
>

Wacoms are quite different since they are not HID devices but handler by
a completely separate driver.

Thanks.

-- 
Dmitry

Re: USB HID plug and play, hardware developer frustration

[Robin Theunis]

Hi Devs, Dmitry

Oh, there is some support for digitizers. That will help me a lot!
Some thing else. When releasing my product how do I "ship" my driver?
Or do I need to hope that it will be included in the kernel?

Thanks

Robin

2011/1/29 Dmitry Torokhov <dmitry.torokhov@gmail.com>:
> Ho Robin,
>
> On Sat, Jan 29, 2011 at 09:15:11AM +0100, Robin Theunis wrote:
>> Hi Devs,
>>
>> Currently I am design a USB product, and in that process I also look
>> if almost every OS supports my device.
>> The device is just only a HID digitizer or touch tablet thingy. It
>> reports it self also as HID device. This is to have it
>> work PLUG and PLAY. But I gotten a cold shower when trying this on my
>> linux pcs. It doesn't work!
>> I did some investigation and found that the linux (kernel) only
>> support mouses and keyboard, all the other usage pages
>> that are included in the USB HID specs aren't implemented.
>> http://www.usb.org/developers/devclass_docs/Hut1_11.pdf
>>
>> Is there a reason why they aren't implemented? especially the
>> digitizer thingies because of all the new tablets?
>
> Linux HID driver does have code to handle digitizers, please take a look
> at drivers/hid/hid-input.c::hidinput_configure_usage().
>
>> Is it difficult
>> to make a driver to support my device?
>
> It should not be. You might need to tweak usage mappings a bit by the
> way of writing small HID sub-driver. Look for examples in
> drivers/hid/hid-<vendor>.c
>
> If you need additional help I'd recommend asking on
> linux-input@vger.kernel.org
>
>> I have seen that there are a
>> lot of wacom drivers, I think doing all the same thing.
>>
>
> Wacoms are quite different since they are not HID devices but handler by
> a completely separate driver.
>
> Thanks.
>
> --
> Dmitry
>

Re: USB HID plug and play, hardware developer frustration

[Dmitry Torokhov]

On Sat, Jan 29, 2011 at 10:15:40AM +0100, Robin Theunis wrote:
> Hi Devs, Dmitry
> 
> Oh, there is some support for digitizers. That will help me a lot!
> Some thing else. When releasing my product how do I "ship" my driver?
> Or do I need to hope that it will be included in the kernel?
> 

If a new driver is indeed needed please take a look at
Documentation/SubmittingPatches and Documentation/SubmittingDrivers and
post it here and also CC Jiri Kosina who is HID maintainer.

And please do not top post.

Thanks.

-- 
Dmitry