Hi,
On Thu, Jun 18, 2020 at 07:00:20PM +0300, Andy Shevchenko wrote:
> On Thu, Jun 18, 2020 at 6:46 PM Jeremy Linton <jeremy.lin...@arm.com> wrote:
> > On 6/17/20 12:34 PM, Andrew Lunn wrote:
> > > On Wed, Jun 17, 2020 at 10:45:34PM +0530, Calvin Johnson wrote:
> > >> From: Jeremy Linton <jeremy.lin...@arm.com>
> > >
> > >> +static const struct acpi_device_id xgmac_acpi_match[] = {
> > >> + { "NXP0006", (kernel_ulong_t)NULL },
> > >
> > > Hi Jeremy
> > >
> > > What exactly does NXP0006 represent? An XGMAC MDIO bus master? Some
> > > NXP MDIO bus master? An XGMAC Ethernet controller which has an NXP
> > > MDIO bus master? A cluster of Ethernet controllers?
> >
> > Strictly speaking its a NXP defined (they own the "NXP" prefix per
> > https://uefi.org/pnp_id_list) id. So, they have tied it to a specific
> > bit of hardware. In this case it appears to be a shared MDIO master
> > which isn't directly contained in an Ethernet controller. Its somewhat
> > similar to a "nxp,xxxxx" compatible id, depending on how they are using
> > it to identify an ACPI device object (_HID()/_CID()).
> >
> > So AFAIK, this is all valid ACPI usage as long as the ID maps to a
> > unique device/object.
> >
> > >
> > > Is this documented somewhere? In the DT world we have a clear
> > > documentation for all the compatible strings. Is there anything
> > > similar in the ACPI world for these magic numbers?
> >
> > Sadly not fully. The mentioned PNP and ACPI
> > (https://uefi.org/acpi_id_list) ids lists are requested and registered
> > to a given organization. But, once the prefix is owned, it becomes the
> > responsibility of that organization to assign & manage the ID's with
> > their prefix. There are various individuals/etc which have collected
> > lists, though like PCI ids, there aren't any formal publishing requirements.
>
> And here is the question, do we have (in form of email or other means)
> an official response from NXP about above mentioned ID?
At NXP, we've assgined NXP ids to various controllers and "NXP0006" is
assigned to the xgmac_mdio controller.
Regards
Calvin
