Re: [PATCH 01/10] arm/tegra: initial device tree for tegra30

[Olof Johansson]

On Fri, Nov 18, 2011 at 11:30 AM, Rob Herring <robherring2@xxxxxxxxx> wrote:
> On 11/18/2011 12:49 PM, Olof Johansson wrote:
>> On Thu, Nov 17, 2011 at 11:39:14AM -0800, Stephen Warren wrote:
>>> Peter De Schrijver wrote at Thursday, November 17, 2011 9:19 AM:
>>>> This patch adds the initial device tree for tegra30
>>>
>>>> diff --git a/Documentation/devicetree/bindings/arm/tegra.txt
>>> ...
>>>> +* harmony: tegra20 based development board
>>>> +Required root node properties:
>>>> + - compatible = "nvidia,harmony", "nvidia,tegra20";
>>>> +
>>>> +* seaboard: tegra20 based clamshell reference design
>>>> +Required root node properties:
>>>> + - compatible = "nvidia,seaboard", "nvidia,tegra20";
>>>
>>> Do we really want to list all the board names here? In the future, there
>>> could be tens or hundreds. I would argue that we should just document
>>> nvidia,tegra20 and nvidia,tegra30.
>>
>> Agreed.
>
> It's not really any different than mach-types which does have every
> board in it.

Yeah, and the whole idea of having device trees is to not have to do
code changes when introducing a new derivative board. So enumerating
all supported boards in the documentation means we're back to an
equivalence to having to add machine ids.

> I think if a board requires a new dts, then it needs a unique name.

Sure, that's fine. But the idea is to be able to do it without
changing code for many cases, just provide a new dts that configures
the devices in question.

>>> At a later point, we should fix board-dt.c to solely look for those
>>> compatible values, although this will have to wait until the pinmux DT
>>> bindings are present. Then, the kernel won't care about the board names.
>>
>> Exactly.
>
> That is perfectly acceptable, but you should still have the option to do
> something specific for any given board.

Of course. That's not what we're objecting to here.


-Olof
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/