On 2013-12-12 16:13, Tomi Valkeinen wrote:
> On 2013-12-12 12:05, Sebastian Reichel wrote:
>> On Thu, Dec 12, 2013 at 09:41:49AM +0200, Tomi Valkeinen wrote:
>>>> A label property is still an option.
>>>
>>> Hmm, what do you mean? Label as in:
>>>
>>> foo : node {
>>> };
>>>
>>> Isn't that 'foo' label only visible in DT itself, as a shortcut?
>>
>> Some driver use a "label" property like this:
>>
>> foo : node {
>> label = "lcd";
>>
>> ...
>> };
>>
>> See for example
>>
>> Documentation/devicetree/bindings/leds/common.txt
>> Documentation/devicetree/bindings/mtd/partition.txt
>
> Ah, I see. That kind of label was actually the first thing I did when
> starting to work on DSS DT. But I removed it, as it didn't describe the
> hardware and I didn't see others using anything similar.
>
> But I guess one could argue it does describe hardware, not in electrical
> level but in conceptual level.
>
> The question is, do we need labeling for displays? For backward
> compatibility omapdss would need it, but in general? I'm quite content
> with having just display0, display1 etc. Using the alias node, those can
> be fixed and display0 is always the same display.
I came to the conclusion that it's better to add the label to keep
backward compatibility, especially as it was very easy to add.
So we'll have 'name' and 'alias' for each display (as we have already).
In the current non-DT boot (which is going away):
- 'alias' is created by omapdss dynamically (first display to be
registered is display0, etc.)
- 'name' comes from platform data
In the DT boot:
- 'alias' comes from the DT aliases node, or if there are no display
aliases, it's created the same way as to non-DT. The code presumes that
there either is a DT alias for all displays, or there are none.
- 'name' comes from 'label' property
In both non-DT and DT cases, if 'name' is NULL (i.e. not set in platform
data or no 'label' property), the alias is used as a name.
I think this works fine, and was a trivial change.
Tomi
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