From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] rtc: ds1307: add trickle charger device tree binding Date: Tue, 9 Sep 2014 13:34:25 +0200 Message-ID: <20140909113425.GC15404@amd> References: <20140828155157.GB23677@roeck-us.net> <20140828161025.GO14650@leverpostej> <20140828164825.GA12153@roeck-us.net> <20140828172842.GF12769@titan.lakedaemon.net> <20140828174034.GC15307@roeck-us.net> <20140829073413.GN4587@fi-ourus-dhcp00977.emea.nsn-net.net> <20140829104001.GB19424@leverpostej> <20140908135242.GA21412@amd> <20140908145825.GO12081@leverpostej> <20140909062158.GB21342@fi-ourus-dhcp00977.emea.nsn-net.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140909062158.GB21342-3P0KQDf13zYjNwtGTSXw41mm0B4v8B71Fo5piaCiEZ7R7s880joybQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matti Vaittinen Cc: ext Mark Rutland , ext Guenter Roeck , Jason Cooper , "a.zummo-BfzFCNDTiLLj+vYz1yj4TQ@public.gmane.org" , "jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "arno-LkuqDEemtHBg9hUCZPvPmw@public.gmane.org" , "jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org" , "san-KGKi0rHxN0fKWSuBa/xFvVpr/1R2p/CL@public.gmane.org" , "hs-ynQEQJNshbs@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org" , Sverdlin Alexander List-Id: devicetree@vger.kernel.org Hi! > > > > trickle-resistor-ohms = <250> > > > > diode-connected; > > > > > > > > That's easy for a human to write and/or validate, we can easily extend > > > > it in future, requires no proliferation of macros, and describes the > > > > hardware rather than telling software what to do. > > > > > > > > The driver becomes a little more complicated, but gains sanity checking, > > > > which is a good thing. > > > > > > Certainly looks better than register bit defines. > > > > > > As rtc-bq32k has similar options, I'm interested, too. I believe we > > > should add > > > > > > trickle-charge-enable; > > I am unsure about this. It makes sense for devices where we cannot > select resistor but just enable or disable charger. Is there any such > devices? For devices like ds1339 this makes no sense. For them it is > simpler to just enable the charger if resistor value is specified, and > default the charger to be off. But I do not see a problem in supporting > the trickle-charge-enable; for devices needing this (independently from > the ds1307 driver). Ok, just cc me on next version of the driver, and I'll adjust bq32k to be similar. > > > (we may not want to charge at all), and I believe the diode should be > > > > > > disconnect-diode; > > > > > > ... With diode connected, charge is slower, and that probably should > > > be the default value. We don't want to give too much current in > > > default case. (bq32k has hard-coded resistor value for > > > diode/not-diode case). > > > > I agree that if one case is less likely to be problematic / damaging > > that should be the default. > > _Maybe_ > diode-connected = <1>; or > diode-connected = <0>; That should work. Actually, make it "connect-diode = <0/1>;", because hardware can actually select if the diode is connected or not. > Then one question regarding the "process". Now if I cook up fourth patch > with inverted diode-connected default for ds1339, should I collect new > acks for this new patch? (V3 was acked by Alessandro and Jason.) I assume > yes. It depends if patch changed "a lot". I guess you can keep the acks. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html