Dell Latitude 7220: eGalax P80H84 0eef:c003 factory passive stylus not detected

[budcomfort]

Hello,

I'm trying to determine whether support for the eGalax P80H84 0eef:c003 used in the Dell Latitude 7220 Rugged Extreme is a known issue or is currently being worked on.

The tablet is running Linux Mint with kernel 7.0.0-31-generic. The touchscreen is:

0eef:c003 D-WAV Scientific Co., Ltd eGalaxTouch P80H84 0710 vA1_N k47_45

It binds to hid-multitouch, and normal finger touch works correctly.

The problem concerns the small factory Dell tethered, buttonless, batteryless hard-tip stylus that stores in the tablet chassis. This is not the optional Dell PN720R active pen.

The factory stylus works with this hardware under Windows, but under Linux it produces no input.

The tablet originally ran Windows, where the factory stylus worked correctly. Windows has since been removed and replaced with Linux Mint, so I no longer have the Windows installation available for comparison testing. I would prefer not to reinstall Windows, although I can perform additional Linux-side diagnostics and test patches or configuration changes on the actual hardware.

So far I have tested:

-   Finger input produces events on /dev/input/event5.
-   The factory passive stylus produces no events on event5.
-   /dev/input/event6 is exposed as a tablet/stylus device with pressure, tilt, in-range, etc., apparently for an active pen. The factory passive stylus produces no events there either.
-   Most importantly, I tested the eGalax device directly through /dev/hidraw4. Finger contact produces raw HID traffic. The factory passive stylus produces no raw HID traffic at all.
-   The device's HID descriptor exposes Report 24 for multitouch and Report 26 for the Pen collection.
-   It also exposes Digitizers.DeviceConfiguration, Feature Report 5, containing Digitizers.DeviceMode and Digitizers.DeviceIdentifier.
-   Reading Feature Report 5 with HIDIOCGFEATURE currently returns: 05 00 00

I noticed the recent MT_CLS_EGALAX_P80H84 work for 0eef:c002, as well as the more recent eGalax/Dell Rugged HID work.

Since the passive stylus produces no report at the hidraw level, I suspect this may involve controller initialization/sensitivity/device mode rather than merely parsing an incoming HID report.

Before experimenting with eGalax vendor feature reports or controller modes, I wanted to ask:

Is 0eef:c003 already a known variant/problem, and is anyone currently working on support for it?

I have the Dell Latitude 7220 hardware available and would be happy to run additional diagnostics or test patches. I can also provide the complete HID report descriptor, dmesg, evtest, libinput, and raw HID results.

Thank you,
Orley E Mosher III, TSgt, USAF, Retired