Hi Arnd,
On Mon, Nov 24, 2014 at 9:15 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Monday 24 November 2014 21:10:05 Geert Uytterhoeven wrote:
>> As this minimal BSC driver isn't hardware-specific at all, I'm wondering
>> if there's a simpler way to do this?
>> - Should the driver be renamed to "simple-bus", and match "simple-bus"?
>> - Should this be moved to core code, without an explicit driver for
>> "simple-bus"? I.e. should the driver core just enable runtime PM for
>> all devices not bound to a driver, as they may represent buses with
>> child devices that do rely on runtime PM?
>>
>> Thanks for your comments and suggestions!
>
> My understanding of simple-bus is that it's something that does
> not have any power-management capabilities, and I'd rather not
> add clocks or interrupts to it.
OK.
> What I think makes more sense is to have a bus driver for it
> in drivers/bus, remove the "simple-bus" compatibility value
> and have the driver take care of registering the power domain
> and probing the child devices using of_platform_populate on
> itself.
Registering power domains is already handled by the core code.
So compared to my RFC code, I only have to
1. Drop "simple-bus" from the compatible property in the .dtsi,
2. Call of_platform_populate() from renesas_bsc_probe(), to
register the child devices, now the core code no longer does that.
I find it a bit strange having to add _more_ code, as the core code handles
registering child devices fine. Doing it from my bus driver only protects
against people trying to run a kernel without my bus driver included
(which currently works fine, as long as no PM domain or clock is involved,
e.g. if the clock is forgotten in the SoC's .dtsi :-).
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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