Re: [PATCH 2/2] x86: intel-mid: add watchdog platform code for Merrifield

From: Alexander Stein
Date: Wed Apr 09 2014 - 10:04:36 EST


On Wednesday 09 April 2014 14:58:48, One Thousand Gnomes wrote:
> > I'm getting curious: How can I use device-tree on x86(_64)?
> > Reading the dependencies from CONFIG_OF it can only be used on 32bit systems with some special hardware bases.
> > So, how to use otherwise?
>
> There isn't any fundamental thing tying device tree to a given
> architecture or 32bitness, it's just that sane PC architectures use ACPI
> to enumerate devices, and/or have a discoverable bus architecture.
>
> Some of the phones don't so this now becoems a point of consideration. In
> fact it's already also used on CE4100 (which is an embedded media SoC
> found in some TV devices and set-top boxes) and on the OLPC (One laptop
> per child). There is no intrinsic reason it couldn't be used in other x86
> special cases.
>
> If its PC shaped however it probably has ACPI and ACPI and DT are not a
> 1:1 mapping. ACPI has method invocations, and various firmware provided
> interfaces such as the EC, Device tree is better at some other bits.

Yep, like SPI devices on embedded x86 hardware.

> Converting the phones to embedded device tree rather than adding a
> billion little platform files on the other hand seems to me like a
> no-brainer.

I found http://thread.gmane.org/gmane.linux.drivers.devicetree/4475. Why didn't that get into mainline?

Best regards,
Alexander
--
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