Re: [PATCH] rtc: ds1307: add trickle charger device tree binding

Pavel Machek
2014-09-08T13:52:47Z

Hi!

> I would suggest we have two properties that describe the resistor's
> rating and whether or not there is a diode:
>
> trickle-resistor-ohms = <250>
> diode-connected;
>
> That's easy for a human to write and/or validate, we can easily extend
> it in future, requires no proliferation of macros, and describes the
> hardware rather than telling software what to do.
>
> The driver becomes a little more complicated, but gains sanity checking,
> which is a good thing.

Certainly looks better than register bit defines.

As rtc-bq32k has similar options, I'm interested, too. I believe we
should add

trickle-charge-enable;

(we may not want to charge at all), and I believe the diode should be

disconnect-diode;

... With diode connected, charge is slower, and that probably should
be the default value. We don't want to give too much current in
default case. (bq32k has hard-coded resistor value for
diode/not-diode case).

Thanks and best regards,
Pavel
--
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