Re: About Goodix-TS on Bay Trail, and ACPI and interrupts

Benjamin Tissoires
2015-01-20T16:32:05Z

On Jan 20 2015 or thereabouts, Mika Westerberg wrote:
> On Mon, Jan 19, 2015 at 10:37:58AM -0500, Benjamin Tissoires wrote:
> > 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:
> > > 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