Re: [PATCH v2 0/4] Add max77620 charging & low battery support

Lee Jones
2019-02-12T08:05:03Z

On Tue, 12 Feb 2019, Mark Zhang wrote:

> On 2/7/2019 4:48 PM, Lee Jones wrote:
> > On Tue, 29 Jan 2019, Mark Zhang wrote:
> >
> >> This patch set adds support for max77620 backup battery charging and
> >> low battery monitoring.
> >>
> >> Changes in v2:
> >> - Add devicetree binding documentation
> >>
> >> Mark Zhang (4):
> >> mfd: max77620: Add backup battery charger support
> >> mfd: max77620: add documentation for backup battery charging
> >> mfd: max77620: Add low battery monitor support
> >> mfd: max77620: add documentation for low battery monitoring
> >>
> >> .../devicetree/bindings/mfd/max77620.txt | 34 +++++
> >> drivers/mfd/max77620.c | 137 +++++++++++++++++-
> >
> > All of this needs moving out to the correct subsystem.
> >
> > drivers/power/supply/max77620-battery.c looks right.
>
> Actually max77620 is not a power supply device. This patch set adds 2
> features:
> - Backup battery charger. The RTC in max77620 is supplied from a backup
> battery and consumes 2.0uA when no other power sources are available. So
> basically this is not a system battery charger, it's just for RTC.
> - Low battery monitoring. This is for monitoring the system main battery
> voltage, so max77620 can shutdown or reset the SoC accordingly. But I
> think this doesn't conform the idea of "power supply" driver as well.

Most other battery handling seems to happen in
drivers/power/supply/*.battery*. If that's not the right location,
then you need to find a place for it to go. MFDs do not provide
useful functionality per say - that is the role of the child devices.

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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