[Gta04-owner] Using touchscreen as a touchpad?

Neil Jerram neil at ossau.homelinux.net
Sat Apr 23 01:19:25 CEST 2016


On 22/04/16 12:00, Neil Jerram wrote:
> On 21/04/16 20:04, Neil Jerram wrote:
>> On 21/04/16 13:08, Neil Jerram wrote:
>>> Has anyone tried configuring the GTA04 touchscreen to behave as a
>>> touchpad instead of a touchscreen?  Would the kernel code for the
>>> touchscreen support that?
>>>
>>> Subject to the latter, I think the former is possible in principle by
>>> using libinput and configuring a udev rule like this:
>>>
>>> ACTION=="add|change", KERNEL=="event[0-9]*", ENV{ID_VENDOR_ID}=="...",
>>> ENV{ID_MODEL_ID}=="...b", ENV{ID_INPUT_TOUCHSCREEN}="",
>>> ENV{ID_INPUT_TOUCHPAD}="1"
>>
>> Well, unfortunately it does not work.  Xorg.0.log says:
>>
>> [    19.473] (II) input device 'TSC2007 Touchscreen', 
>> /dev/input/event0 is tagged by udev as: Touchpad Touchscreen
>> [    19.473] (EE) kernel bug: device TSC2007 Touchscreen failed 
>> touchpad sanity checks
>> [    19.473] (II) input device 'TSC2007 Touchscreen', 
>> /dev/input/event0 is a touchpad
>> [    19.540] (II) failed to create input device '/dev/input/event0'.
>>
>> I guess libinput is expecting some minimal characteristics for a 
>> 'touchpad', and the TSC2007 kernel driver doesn't provide those. 
>> Pity, because I would like to see if it was usable that way.
>
> Yes, libinput checks for ABS_X, BTN_TOUCH and BTN_TOOL_FINGER. The 
> driver provides ABS_X and BTN_TOUCH but not BTN_TOOL_FINGER.
>
> It looks like a trivial change to get the driver to advertise 
> BTN_TOOL_FINGER, so I plan to try that next.  If it works we could 
> implement a driver option for it, so as to allow either touchscreen or 
> touchpad use.

Just hit a further problem here: the amd64->armhf cross-compilation 
toolchain now in Debian is GCC 5, but the kernel back at 3.17 didn't 
support building with GCC 5.  Is there a much more recent kernel - since 
whenever the GCC 5 support was added - that more or less runs correctly 
on the GTA04?

Thanks,
     Neil



More information about the Gta04-owner mailing list