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

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

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")
    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