Re: [PATCH 03/13] RTC: ds1307: Add DS1341 specific power-saving options

From: Alexandre Belloni
Date: Tue Jun 21 2016 - 17:09:28 EST


On 21/06/2016 at 15:49:04 -0500, Rob Herring wrote :
> So wouldn't you want to set one mode while running and the lower power
> mode while suspended? I'm trying to understand the frequency of changing
> this. If it is always one setting for a board, then yes it belongs in
> DT. If it is a user decision, then it probably shouldn't be in DT.
>
> Seeing as these are reused, I've probably already had this discussion...
>

I would agree with Rob here. It may be better to provide a sysfs
interface to configure that particular behavior. This is usually ok
because the use case is:
- the RTC is not configured, time has never been set
- time is set for the first time
- the user can set the oscillator mode/detection/...
- on subsequent reboots, the mode is kept alongside the time and date

I would advise against trying to set a mode automatically in the driver
because you may have unexpected power cuts and it may then let the RTC
consume more power than what you really want.

> > > They should have vendor prefix and be explicit that they are boolean.
> >
> > I was trying to be consistent with ds1339 and ds1390 bindings which do
> > not have vendor prefixes. Will fix in v2.
>
> Okay, then they are fine if you are using existing properties. Perhaps
> these should all be in a common binding doc though.
>

I'll try to collect the existing common properties and write that doc
this week.

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com