Add devd rule for Elantech touchscreens.

[jonathan]

Summary

The touchscreen in the HP Spectre x360 is made by Elantech rather than
Wacom. Adding this devd rule starts webcamd properly for such devices,
enabling their use with the X evdev driver.

[• hselasky]

Could you dump the device and configuration descriptor of your device?

usbconfig -d X.Y dump_curr_config_desc dump_device_desc

I wonder if the rule can be made more generic?

Else patch looks good.

[jonathan]

usbconfig output is here: http://pastebin.com/iqJix3h2

Do you mean that we should use the iManufacturer and iProduct rather than idVendor and idProduct? Those do look a bit more generic, but I'm afraid I don't know how to write that rule. :)

[• hselasky]

No, sometimes the device use 0xff for some ID fields which means propritary driver. It might be better to match that than vendor/product.

[• hselasky]

Ping.

[jonathan]

No, sometimes the device use 0xff for some ID fields which means propritary driver. It might be better to match that than vendor/product.

Sorry, I still don't quite understand: when you say, "it might be better to match that", what "that" are you referring to? To "some ID fields"? I don't see any 0xff values in the usbconfig output that I posted...

I'm not at all familiar with devd, so I don't really know how to make the rule more generic. If you could suggest a different rule then I'd be happy to test it...

[jonathan]

Ping?

[• hselasky]

Looks good.

[• hselasky]

FYI: https://github.com/hselasky/ports/commit/f6b99c1b84b1582d70ebe3e3392960c697ff3733#diff-1649a38df42a596426a2c3f6be508602

[val_packett.cool]

Is this one not supported by wmt(4)? The elan touchscreen on my Thinkpad X240 (0x04f3 : 0x0140) works great with wmt(4), but webcamd used to lose touch-end events...

[jonathan]

In D8397#337061, @greg_unrelenting.technology wrote:

Is this one not supported by wmt(4)? The elan touchscreen on my Thinkpad X240 (0x04f3 : 0x0140) works great with wmt(4), but webcamd used to lose touch-end events...

kldload wmt doesn't seem to do anything: no dmesg output and no new devices in /dev/input. For what it's worth, the output from evemu-describe (when running webcamd) is:

# Input device name: "ELAN Touchscreen"
# Input device ID: bus 0x03 vendor 0x4f3 product 0x2071 version 0x110