On 8/25/20 5:32 PM, Alexandre Belloni wrote: > Hi, > > On 24/08/2020 15:32:22+0200, Bastian Krause wrote: >> On 8/24/20 1:31 PM, Bastian Krause wrote: >>> >>> On 4/15/20 8:56 PM, Alexandre Belloni wrote: >>>> On 15/04/2020 18:37:00+0200, Bastian Krause wrote: >>>>> Signed-off-by: Bastian Krause <bst@xxxxxxxxxxxxxx> >>>>> --- >>>>> Documentation/devicetree/bindings/rtc/rtc-ds1307.txt | 3 +++ >>>>> 1 file changed, 3 insertions(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >>>>> index 66f0a31ae9ce..987a0c9e0cd7 100644 >>>>> --- a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >>>>> +++ b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt >>>>> @@ -34,6 +34,9 @@ Optional properties: >>>>> - trickle-diode-disable : ds1339, ds1340 and ds 1388 only >>>>> Do not use internal trickle charger diode >>>>> Should be given if internal trickle charger diode should be disabled >>>>> +- aux-voltage-chargeable: rx8130 only >>>>> + Epsons's rx8130 supports a backup battery/supercap. >>>>> + This flag tells whether the battery/supercap is chargeable or not. >>>>> >>>> >>>> I think we should make that a generic property and this should supersede >>>> trickle-diode-disable which is a bit wonky as I would prefer the default >>>> to be disabled instead of enabled with the current semantics. >>> >>> Alright, I think I know how to transform the RTC drivers. >>> >>> One question about the DTs though: >>> >>> This means we should remove "trickle-diode-disable" from all upstream >>> DTs and add "aux-voltage-chargeable" to all upstream DTs that use a RTC >>> compatible whose driver care in their probe function for >>> "trickle-diode-disable", right? >> >> Sorry, forget that. >> >> Here's the situation: >> >> Currently there is a switch to explicitly disable charging, so the >> default is to charge. We cannot introduce another boolean switch to turn >> that the other way around, because that would change the default and >> break backwards compatibility. >> >> The only way I can think of is to introduce "aux-voltage-chargeable" not >> as a boolean switch but as an integer, without any default. If this >> property is not available, the drivers should simply do what they did >> prior to this change (look for the legacy trickle-diode-disable, use the >> default they used before). >> >> Are you okay with that? >> > > I agree boolean should be avoided in RTC drivers because we need a way > to express "don't change this value". Alright. >> Some more context: >> >> I originally tried to add a chargeable flag for rx8130. Prior to this >> patch, there was no need to set "trickle-diode-disable" for this, >> because the driver did not pass the chargeable flag to the RTC. With the >> patch the default would have been to charge as long as >> "trickle-diode-disable" is not there. So there's a change in behavior. >> > > Yes, IIRC, my point was simply to move the documentation for > aux-voltage-chargeable to the generice rtc binding documentation, > Documentation/devicetree/bindings/rtc/rtc.yaml > > For now, you sould keep support for trickle-diode-disable but it has to be > superseded by aux-voltage-chargeable if present. Is that more clear? Yes, thanks for the clarification. Should I set the deprecated flag for trickle-diode-disable in the dt-binding yaml? Regards, Bastian -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
