Re: [PATCH] [v7] net: emac: emac gigabit ethernet controller driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Mon, Aug 15, 2016 at 3:06 PM, Timur Tabi <timur@xxxxxxxxxxxxxx> wrote:
> + Rafael and Al, for ACPI help.
>
> Rob Herring wrote:
>>>
>>> >+Optional properties:
>>> >+- phy-version : the version of the integrated emac phy, either 1 or 2.
>
>
>> Sounds like 2 different h/w. The compatible property should distinguish
>> this.
>
>
> So I implemented this in v8 of my driver, but it is causing problems for
> ACPI.
>
> In ACPI, the equivalent to a compatible string is the HID, which is QCOM8070
> for the EMAC.  The problem is that it's very difficult, if not impossible,
> to create new HIDs for different versions of the same device.

Different versions are different devices IMO.

> The driver will primarily (if not exclusively) be used on ACPI platforms,
> not DT.  In Qualcomm, DT is for mobile chips, and ACPI is for server.  To my
> knowledge, there are no plans to use this driver on an actual DT-enabled
> platform, but I want to support DT anyway.
>
> The other problem is that the "internal PHY" of the EMAC is technically a
> separate device, and it's interchangeable.  Future versions of our chips
> will use different internal PHYs, but the EMAC will stay the same.

How do you know? EMAC could just as easily change. It's Gigabit today,
10G tomorrow.

But if it is separate, then maybe you should model it as a separate
device using the phy binding.

> So I would like a solution that works on DT and ACPI.  I suppose I could use
> compatible strings on DT, and a "phy-version" DSD (property) on ACPI.  If
> that's acceptable to everyone, then I can do that.  It seems clunky to me.

On one hand, why should I care about ACPI for defining DT bindings?
OTOH, having a phy-version property alone would not be a big deal, but
you still need distinct compatible strings regardless.

Rob
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux