Messages in this thread | | | Date | Wed, 08 Oct 2014 10:46:28 +0200 | From | Javier Martinez Canillas <> | Subject | Re: [PATCH] regulator: rk808: Add support setting suspend voltage |
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Hello Doug,
On 10/07/2014 07:48 PM, Doug Anderson wrote: > > I don't have all the right patches to test this right now. Hopefully > you can point me at what we're using right now. I'd expect that this > will need the patches that Chanwoo and Javier are working on, so I've > added them to this. >
Yes, you will need Chanwoo's series in order to use this. If also the driver needs to set a default initial regulator operating mode, it will need the series I'll post today but in that case also a .set_mode handler is needed.
> One point of curiosity (maybe this is a question for Chanwoo and > Javier): I'd expect that if someone didn't explicitly setup a "suspend > voltage" that their voltage would just be left alone at suspend time. > I believe that won't be the case for your driver. The rk808 will (I > think) automatically transition to the "suspend voltage" settings for > ALL regulators at suspend time. If you didn't explicitly set the > suspend voltage then you'll move to whatever the default voltage is, > right? >
On system suspend, the regulator core only calls the .set_suspend_voltage handler if struct regulator_state *rstate->uV > 0 for the given suspend state (mem,disk,standby) and only calls .set_suspend_{enable,disable} if struct regulator_state *rstate->{enabled,disable} are set for that state.
Chanwoo's series have different DT properties that are used to set the suspend state uV (regulator-volt) and disabled (regulator-off-in-suspend):
ldoX_reg: LDOx { ... regulator-state-mem { regulator-volt = <1200000>; regulator-off-in-suspend; }; ... };
So answering your question, the transition to the "suspend voltage" setting will only happen if uV is set (regulator-volt), otherwise it will be left alone at suspend time just like is left alone on disable.
However, Chanwoo said that he will drop the regulator-volt DT property from v5 [0]. It seems that is a useful use case for others to set the regulator voltage on suspend, so maybe Chanwoo can address the issues pointed out by Mark about renaming it to regulator-uV [1] and revise the check for the voltage range [2] but kept the DT property on v5?
> -Doug >
Thanks a lot and best regards, Javier
[0]: https://lkml.org/lkml/2014/9/28/202 [1]: https://lkml.org/lkml/2014/9/4/652 [2]: https://lkml.org/lkml/2014/9/4/651
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