Hi Mark,

Mark Brown [off-list ref] hat am 27. Januar 2015 um 01:16 geschrieben:


On Mon, Jan 26, 2015 at 08:46:45PM +0100, Stefan Wahren wrote:

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Does a common property name exists for the switching frequency or would
it be vendor specific?

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As far as I know most regulators have fixed switching frequencies,
so there is no common property name so far. I added regulator
framework people, since this property should be regulator specific.

No, it's pretty common for there to be a couple of options - there's
normally a performance tradeoff (power for regulation accuracy and/or
cost) which can be selected. IIRC it's selected at design time as it
affect the choice of passives on the board.

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okay i understand. But doesn't it need a extra driver to set the switching
frequency because of the new compatible string?

I don't understand this bit at all, sorry.

Sebastian suggested a new sub-node in the devicetree:

    powerpll {
        compatible = "fsl,imx28-power-pll"
        #clock-cells = <0>;
        clock-frequency = <12345>;
    }

and i think that the new compatible string needs a separate driver to take care
of the switching frequency.

Or is it okay to leave the handling of the switching frequency in the mxs-power
driver?

Btw if we add a new node to set switching frequency, i think it would be better
to describe the dc-dc convertor and not the pll:

    dcdc {
       compatible = "fsl,imx28-dcdc"
       frequency = <12345>;
    }

What do you think?

Best regards
Stefan

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At this point i think about moving this feature into the bootloader.

@Fabio, @Marek:

What's your opinion about that?

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-- Sebastian

Stefan