linux-kernel - Re: [PATCH] gpiolib: acpi: Support GpioInt with active

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Date:   Thu, 29 Oct 2020 16:34:23 +0100
From:   Ricardo Ribalda <ribalda@...gle.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        linux-gpio@...r.kernel.org, linux-acpi@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] gpiolib: acpi: Support GpioInt with active_low polarity

Hi Andy

On Thu, Oct 29, 2020 at 3:38 PM Andy Shevchenko
<andriy.shevchenko@...ux.intel.com> wrote:
>
> On Wed, Oct 28, 2020 at 06:17:57PM +0100, Ricardo Ribalda wrote:
> > On the current implementation we only support active_high polarity for
> > GpioInt.
> >
> > There can be cases where a GPIO has active_low polarity and it is also a
> > IRQ source.
> >
> > De-couple the irq_polarity and active_low fields instead of re-use it.
> >
> > With this patch we support ACPI devices such as:
>
> Is it real device on the market?!

Yes, it is a chromebook.

>
> This table is broken. _DSD GPIO active_low is only for GpioIo().

AFAIK the format of the _DSD is not in the ACPI standard. We have
decided its fields. (please correct me if I am wrong here)

On the other mail I have described why we need to make use of the
active_low on a GpioInt()

If there is another way of describing ActiveBoth + inverted polarity
please let me know and I will go that way.

Thanks

>
> If it is a ChromeBook, please fix the firmware.
>
> > Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
> > {
> >         GpioInt (Edge, ActiveBoth, Exclusive, PullDefault, 0x0000,
> >         "\\_SB.PCI0.GPIO", 0x00, ResourceConsumer, ,
> >         )
> >         {   // Pin list
> >                 0x0064
> >         }
> > })
> > Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
> > {
> >         ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301") /* Device Properties for _DSD */,
> >         Package (0x01)
> >         {
> >         Package (0x02)
> >         {
> >                 "privacy-gpio",
> >                 Package (0x04)
> >                 {
> >                 \_SB.PCI0.XHCI.RHUB.HS07,
> >                 Zero,
> >                 Zero,
> >                 One
> >                 }
> >         }
> >         }
> > })
>
>
> --
> With Best Regards,
> Andy Shevchenko
>
>


-- 
Ricardo Ribalda