On Jan 20 2015 or thereabouts, Mika Westerberg wrote:

On Mon, Jan 19, 2015 at 10:37:58AM -0500, Benjamin Tissoires wrote:

quoted

Hi Antonio,

[adding Mika in CC, he implemented most of the ACPI and GPIO for
i2c-hid]

On Jan 17 2015 or thereabouts, Antonio Ospite wrote:

quoted

Hi,

I am trying to make the Goodix driver (drivers/input/touchscreen/goodix.c)
working with a Teclast X98 Air 3G, a tablet based on Intel Bay Trail,
but I am new to ACPI and I could use some help.

I am working with a 3.19-rc4 kernel compiled for x86_64.

This is the DSDT section in the UEFI firmware:

            Device (TCS0)
            {
                Name (_ADR, Zero)  // _ADR: Address
                Name (_HID, "GODX0911")  // _HID: Hardware ID
                Name (_CID, "PNP0C50" /* HID Protocol Device (I2C bus) */)  // _CID: Compatible ID

urgh, this is bad. It declares itself as i2c-hid, but it is not :(
Anyway, according to your logs, i2c-hid probe() just fails, so it's not
a big problem.

Actually, I think this device should use i2c-hid. All the ACPI plumbing
is there including _DSM.

What makes you think it should use the goodix driver?

The fact that the 3.19-rc4 log says:
[    2.424370] i2c_hid i2c-GODX0911:01: unexpected HID descriptor bcdVersion (0x0000)

Which is rather troublesome and shows that we might have received a 0
answer when requesting the HID descriptor. Then Antonio tried to poke
the device with the goodix driver and got a better answer from the
version point of view.

Cheers,
Benjamin