RE: [PATCH 4/4] ARM64: dts: imx: add i.MX8QXP system controller RTC support
From: Anson Huang
Date: Wed Nov 28 2018 - 04:41:30 EST
Best Regards!
Anson Huang
> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@xxxxxxxxxxx]
> Sent: 2018å11æ28æ 17:34
> To: Anson Huang <anson.huang@xxxxxxx>
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> Subject: Re: [PATCH 4/4] ARM64: dts: imx: add i.MX8QXP system controller
> RTC support
>
> On 28/11/2018 09:21:56+0000, Anson Huang wrote:
> > > > This module is NOT depending on any board design, should it be
> > > > enabled by
> > > default in soc dtsi?
> > > > Like wdog etc..
> > > >
> > >
> > > I guess the point is that you may not want it enabled, even if it
> > > should always be working. enabling it by default would affect the RTC
> ordering for example.
> >
> > i.MX SoCs ONLY have 1 RTC. And RTC are always enabled by default for
> > all i.MX SoCs, so do we have to disable it here and enable it in board dts?
> >
>
> I would say that most of the i.MX based boards include another RTC because
> the SoC one consumes way too much power.
>
> Note that I don't care too much whether it is enabled by default, I was simply
> explaining why you may want to disable it by default.
OK, this system controller RTC is a little different, it is controlled by system controller firmware,
and system controller firmware will always select the best one for its user(Linux kernel) if there are other
RTCs available, so I think we can keep it enabled by default for now. Thanks.
Anson.
>
> --
> Alexandre Belloni, Bootlin
> Embedded Linux and Kernel engineering
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