Re: How to add the "gpio-line-names" property in a PCI gpio expander

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi,

On Thu, Nov 05, 2020 at 12:51:18PM +0100, Rafael J. Wysocki wrote:
> CC Mika and Andy who should be more familiar with that problem space than I am.
> 
> On Thu, Nov 5, 2020 at 10:46 AM Flavio Suligoi <f.suligoi@asem.it> wrote:
> >
> > Hi all,
> >
> > I'm working to introduce the "gpio-line-names" property in the ACPI
> > configuration of the BIOS of our x86 boards (we can customize the BIOS of our
> > boards).
> >
> > All is ok for the gpiochips related to the Intel chipset and some I2C gpio
> > expanders. I have inserted the _DSD as described in the Linux documentation.
> >
> > In one of our boards we have an add-on PCI board, with a PCI serial device
> > Exar XR17V352. This device also contains 16 gpios.
> > The exar device drivers work good, both the "8250_exar" and the "gpio_exar", and
> > I can manage the exar's gpios correctly.
> > The problem is how to assign the gpio-line-names property to a PCI gpio
> > expanders like this.
> >
> > I tried adding a new device in my ACPI configuration, as:
> >
> > Device (EXAR)
> > {
> >     Name (_HID, "13A80352")

If this is PCI device then you need to have _ADR here instead of _HID.

> >     Name (_STR, Unicode ("STR - Exar GPIOs"))  // _STR: Description String
> >
> >     Name (_DSD, Package () {
> >         ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >         Package () {
> >             Package () {
> >                 "gpio-line-names",
> >                     Package () {
> >                         "exar_0",
> >                         "exar_1",
> >                         "exar_2",
> >                         "exar_3",
> >                         ...
> >                     }
> >                 }
> >             }
> >     })
> > }
> >
> > but I have no result.
> > Does anyone have a suggestion?
> >
> > Thanks,
> >
> > Flavio