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

[Flavio Suligoi <f.suligoi@asem.it>]

Hi Mika,

> > > > > 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.
> >
> > the problem is that the parent bus of this device is not declared in any
> ACPI table.
> > The exar chip is on the bus 7 :
> >
> > 07:00.0 Serial controller: Exar Corp. XR17V3521 Dual PCIe UART (rev 03)
> >
> > and in the _ADR object you can specify device and function only.
> > How can I specify the parent bus? It is not simple …
> > The lspci output is the following:
> 
> The parent is the root port the device is connected to and I'm pretty
> sure it exists in the namespace as this seems to be Intel hardware. If
> you run 'lspci -t' it shows you the root port.
> 
> The _ADR should be 0 for this one.

Unfortunately there is bridge in the middle:

root@debian:~# lspci -t
-[0000:00]-+-00.0
           +-02.0
           +-0e.0
           +-0f.0
           +-12.0
           +-13.0-[01]----00.0
           +-13.1-[02]----00.0
           +-13.2-[03]--
           +-14.0-[04]----00.0
           +-14.1-[05-09]----00.0-[06-09]--+-01.0-[07]----00.0 <-- Exar (bus 7, dev 0, funct 0)
           |                               +-02.0-[08]----00.0
           |                               \-03.0-[09]--
           +-15.0
           +-16.0
           +-16.1
           +-19.0
           +-19.1
           +-19.2
           +-1f.0
           \-1f.1
root@debian:~#

My changes in the ACPI:

Scope (_SB.PCI0) {
    Device (EXAR)
		{
			Name (_ADR, 0x0000)
....

but it doesn't work, because of the bridge.

Regards,

Flavio