Re: [PATCH V2 5/6] regulator: add mxs on-chip regulator driver

On Tue, May 26, 2015 at 02:16:55PM +0200, Stefan Wahren wrote:

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Mark Brown [off-list ref] hat am 7. Mai 2015 um 21:32 geschrieben:

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In the bootloader code enabling the DC-DC is critical. There is a known
issue
which falsely triggers the brownout detection.

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Why would the driver not provide these operations?

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I didn't implement this operation because the suggested workaround for the
hardware issue isn't very nice
(disable brownout detection during enabling DC-DC). I was afraid of the
implementation.

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That doesn't sound too complicated?

Okay, i think i managed the brownout handling.

Unfortunately i'm stuck at the next step. The DC-DC (3 way output) can supply 3
LDOs vddd, vdda, vddio. In case of a DC-DC state change the 3 regulators needs
to be reconfigured before.

I tought of REGULATOR_EVENT_PRE_DISABLE and REGULATOR_EVENT_PRE_ENABLE events,
but i'm not sure that's the right way to achieve a synchronization between DC-DC
and consuming LDOs.

OK, that's possibly sounding a bit complicated.  Is it just a case of
writing some value, doing a reconfiguration and rewriting the original
value or is it something more?  If it's much more complicated than that
then I think putting a comment in the driver explaining what the issue
is would be the right step, that would address the issue with the driver
looking strange.