On 11.09.2015 05:57, Andreas Dannenberg wrote: > On Thu, Sep 10, 2015 at 09:15:09AM +0900, Krzysztof Kozlowski wrote: (...) > >>>> bq2415x.txt - ti,current-limit - maximum current to be drawn in mA >>>> >>>> New bindings: >>>> ti,charge-current (bq24261) - default charge current in mA >>>> ti,max-charge-current (bq24261) - maximum charging current in mA >>> >>> This ti,max-charge-current is actually an interesting one. It's not a >>> device setting as it does not impact any of the device registers at all. >>> Instead, it's an artificial limit that can be set through DT that >>> prevents somebody from going into sysfs and configuring a charge current >>> higher than ti,max-charge-current. In other drivers I have seen that the >>> sysfs property reflecting that max charge current is just read-only and >>> gives you the maximum the HW is capable of. From a device point of view >>> there is nothing configurable about this property. >> >> Hmmm, so now I wonder whether this should be a DT binding. The purpose >> of DT isn't the control of the driver like enable some stuff, set some >> value used by the driver. The DT provides information about hardware so >> the driver could properly configure the device and work with it. >> >> Reason to put this into DT would be: >> For example one device configuration (device, board, connected battery) >> could handle one maximum value and the other configuration would require >> lower one. The device and its capabilities (bq24257 for example) are the >> same but configuration changes. > > Yes this could be useful in this case but this property only makes sense > if userspace is allowed to change the actual charge current through > sysfs as some drivers do including Ram's proposed bq24261 driver. But if we > get rid of the general sysfs configurability of the charge current > (which I say we should) we don't need that ti,max-charge-current property. > Also see... > > http://marc.info/?l=linux-pm&m=143080413218161&w=2 Right, that's my previous reply. :) I must admit that here and for bq24261 I looked mostly at bindings so I did not initially about the sysfs interface. Anyway I am not convinced to having such sysfs interfaces and definitely they should not mess with DT. I would rather expect these to be totally orthogonal. Summarizing all these bq24261 properties: - ti,enable-user-write - ti,max-charge-current - ti,max-charge-voltage are related to that sysfs interface, not to hardware configuration. If that's true, then all should be gone. > >> To prevent future issues in naming and bindings consistency maybe there >> should be a dedicated maintainer for bq/TI charger devices? Pali Rohar >> recently took care for devices related to Nokia N900 but maybe someone >> from TI should also take care of rest or all of them (if TI is >> interested in this)? > > I'd be happy to step in here. Let me know how I can help and contribute. I don't know Sebastian's opinion on that idea but I think usually a new maintainer and reviewer of particular drivers is welcomed by community. I see also Intel's interest and his contributions in these chargers. Laurentiu seems to do a thorough review as well. There can be both official reviewers. It's up to you people. Just make a first step and we'll see how other people react (and what Sebastian thinks about it :) ). Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
