Re: [PATCH v8 0/9] Goodix touchscreen enhancements

[Arnd Bergmann <arnd@arndb.de>]

On Friday 09 October 2015 11:02:01 Tirdea, Irina wrote:
> > -----Original Message-----
> > From: linux-input-owner@vger.kernel.org [mailto:linux-input-owner@vger.kernel.org] On Behalf Of Arnd Bergmann
> > Sent: 08 October, 2015 17:32
> > To: Tirdea, Irina
> > Cc: Dmitry Torokhov; Bastien Nocera; Aleksei Mamlin; linux-input@vger.kernel.org; Mark Rutland; Purdila, Octavian; linux-
> > kernel@vger.kernel.org; devicetree@vger.kernel.org
> > Subject: Re: [PATCH v8 0/9] Goodix touchscreen enhancements
> > 
> > On Thursday 08 October 2015 17:23:42 Irina Tirdea wrote:
> > > Add several enhancements to the Goodix touchscreen driver.
> > >
> > > The new functionality is only available for devices that
> > > declare named gpio pins for interrupt and reset in their
> > > ACPI/DT configuration.
> > >
> > > Thanks,
> > > Irina
> > >
> > > Changes in v8:
> > >  - only allow new functionality for devices that declare named
> > > gpios (using _DSD properties in ACPI or named DT properties)
> > >
> > >
> > 
> > Looks much cleaner this way, thanks!
> > 
> > One remaining question: how would you handle the case where
> > the hardware doesn't support configuring the int-gpios line
> > as output but you still want to use the named gpios?
> > 
> 
> The only reason to use named gpios is to enable the new functionality
> introduced by this patch set (mainly reset and power management).
> You cannot use only one gpio either (e.g. only reset gpio but not the
> interrupt gpio), you need both for this functionality to work.
> 
> If the hardware does not support using the interrupt gpio pin as output,
> it should not declare the named int-gpio pin in ACPI. It is true that
> we might later run into platforms that declare the int-gpio pin even if it
> does not actually work (just like we now have the indexed gpio pins).
> I could have added an additional property for this as you first suggested,
> but if we can modify the ACPI to add it, we could simply remove the
> named interrupt pin instead (that does not work anyway).

Ok, got it. Thanks,

	Arnd