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Message-ID: <YrLw+um7l9LbPqhu@lunn.ch>
Date: Wed, 22 Jun 2022 12:37:46 +0200
From: Andrew Lunn <andrew@...n.ch>
To: Marcin Wojtas <mw@...ihalf.com>
Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
netdev <netdev@...r.kernel.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
Len Brown <lenb@...nel.org>, vivien.didelot@...il.com,
Florian Fainelli <f.fainelli@...il.com>,
Vladimir Oltean <olteanv@...il.com>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, pabeni@...hat.com,
Russell King - ARM Linux <linux@...linux.org.uk>,
Heiner Kallweit <hkallweit1@...il.com>,
Grzegorz Bernacki <gjb@...ihalf.com>,
Grzegorz Jaszczyk <jaz@...ihalf.com>,
Tomasz Nowicki <tn@...ihalf.com>,
Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@....com>,
upstream@...ihalf.com
Subject: Re: [net-next: PATCH 09/12] Documentation: ACPI: DSD: introduce DSA
description
On Wed, Jun 22, 2022 at 12:22:23PM +0200, Marcin Wojtas wrote:
> śr., 22 cze 2022 o 11:24 Andrew Lunn <andrew@...n.ch> napisał(a):
> >
> > On Wed, Jun 22, 2022 at 11:08:13AM +0200, Marcin Wojtas wrote:
> > > wt., 21 cze 2022 o 13:42 Andy Shevchenko
> > > <andriy.shevchenko@...ux.intel.com> napisał(a):
> > > >
> > > > On Tue, Jun 21, 2022 at 01:18:38PM +0200, Andrew Lunn wrote:
> > > > > On Tue, Jun 21, 2022 at 02:09:14PM +0300, Andy Shevchenko wrote:
> > > > > > On Mon, Jun 20, 2022 at 09:47:31PM +0200, Andrew Lunn wrote:
> > > >
> > > > ...
> > > >
> > > > > > > > + Name (_CRS, ResourceTemplate ()
> > > > > > > > + {
> > > > > > > > + Memory32Fixed (ReadWrite,
> > > > > > > > + 0xf212a200,
> > > > > > > > + 0x00000010,
> > > > > > >
> > > > > > > What do these magic numbers mean?
> > > > > >
> > > > > > Address + Length, it's all described in the ACPI specification.
> > > > >
> > > > > The address+plus length of what? This device is on an MDIO bus. As
> > > > > such, there is no memory! It probably makes sense to somebody who
> > > > > knows ACPI, but to me i have no idea what it means.
> > > >
> > > > I see what you mean. Honestly I dunno what the device this description is for.
> > > > For the DSA that's behind MDIO bus? Then it's definitely makes no sense and
> > > > MDIOSerialBus() resources type is what would be good to have in ACPI
> > > > specification.
> > > >
> > >
> > > It's not device on MDIO bus, but the MDIO controller's register itself
> >
> > Ah. So this is equivalent to
> >
> > CP11X_LABEL(mdio): mdio@...200 {
> > #address-cells = <1>;
> > #size-cells = <0>;
> > compatible = "marvell,orion-mdio";
> > reg = <0x12a200 0x10>;
> > clocks = <&CP11X_LABEL(clk) 1 9>, <&CP11X_LABEL(clk) 1 5>,
> > <&CP11X_LABEL(clk) 1 6>, <&CP11X_LABEL(clk) 1 18>;
> > status = "disabled";
> > };
> >
> > DT seems a lot more readable, "marvell,orion-mdio" is a good hint that
> > device this is. But maybe it is more readable because that is what i'm
> > used to.
>
> No worries, this reaction is not uncommon (including myself), I agree
> it becomes more readable, the longer you work with it :).
>
> IMO the ACPI node of orion-mdio looks very similar. Please take a look:
>
> Device (SMI0)
> {
> Name (_HID, "MRVL0100") // _HID: Hardware ID
> Name (_UID, 0x00) // _UID: Unique ID
> Method (_STA) // _STA: Device status
> {
> Return (0xF)
> }
> Name (_CRS, ResourceTemplate ()
> {
> Memory32Fixed (ReadWrite,
> 0xf212a200, // Address Base
> 0x00000010, // Address Length
> )
> })
> }
>
> You can "map" the objects/methods to what you know from DT farly easily:
> _HID -> compatible string
MRVL0100 is pretty meaningless, but marvell,orion-mdio gives you a
much better idea what the device is. That i would say is the key of
the problem here. Without knowing what MRVL0100 means, it is hard to
guess the rest.
Andrew
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