Re: [PATCH 3/4] OMAPDSS: panel-sharp-ls037v7dw01: add device tree support

Tomi Valkeinen
2014-05-12T09:40:22Z

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On 12/05/14 12:34, Javier Martinez Canillas wrote:

> Maybe we can remove this hackery by relying on the fact that a
> compatible string can have a set of values that goes from more
> specific to more general. So you can have something like:
>
> compatible = "sony,panel-foobar", "omapdss,panel-foobar"
>
> So right now only "omapdss,panel-foobar" will be matched and later
> when we have common panel drivers then that driver could handle the
> "sony,panel-foobar" compatible string.
>
> Other platforms could do something similar and have
>
> compatible = "sony,panel-foobar", "baz,panel-foobar"
>
> That way you won't break DT backward compatible but still not require
> hacks on arch/arm/mach-omap2/display.c.
>
> We do the same for OMAP boards, we now have the following compatible string:
>
> compatible = "isee,omap3-igep0020", "ti,omap36xx", "ti,omap3";
>
> There isn't a struct machine_desc that matches "isee,omap3-igep0020"
> but later if we find that we need some board specific initialization
> we could add one without breaking existing DTS. In fact it used to be
> a single machine_desc that matched "ti,omap3" for both omap36xx and
> omap34xx but later when some DT clocks changes were introduced we
> needed to split both SoC families.

I think that's a different thing. "isee,omap3-igep0020" is a proper
compatible string, if the board is "isee,...". No matter what software
you run, that's correct and fine.

The omapdss case is different, there the "omapdss" points to a sw thing,
it does not describe the hardware. It's only needed as we don't have
proper sw drivers for the devices.

That said, I think what you describe would work. But I would rather keep
the .dts files clean and correct, and keep that hacks hidden inside the
kernel.

Tomi

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