On Tue 2015-06-02 16:06:47, Dr. H. Nikolaus Schaller wrote: > Hi, > > Am 02.06.2015 um 15:49 schrieb Kishon Vijay Abraham I <kishon@xxxxxx>: > > > Hi, > > > > On Tuesday 02 June 2015 03:07 AM, NeilBrown wrote: > >> On Mon, 1 Jun 2015 19:06:52 +0530 Kishon Vijay Abraham I <kishon@xxxxxx> > >> wrote: > >> > >>> Hi, > >>> > >>> On Thursday 16 April 2015 01:33 PM, NeilBrown wrote: > >>>> From: NeilBrown <neilb@xxxxxxx> > >>>> > >>>> The twl4030 phy can measure, with low precision, the > >>>> resistance-to-ground of the ID pin. > >>>> > >>>> Add a function to read the value, and export the result > >>>> via sysfs. > >>> > >>> Little sceptical about adding new sysfs entries. Do you have a good reason to > >>> add this? > >> > >> The hardware can report the value, so why not present it to user-space? > >> > >> I originally used this with a udev rule which would configure the maximum > >> current based on the resistance measure - to work with the particular charger > >> hardware I have. > >> > >> More recent patches try to do all of the max-current configuration in the > >> kernel, so I could live without exporting the value via sysfs if that is a > >> show-stopper. > >> > >> I can't see where the scepticism comes from though. It is a well defined > >> and cleary documented feature of the hardware. Why not expose it? Is it well defined enough that it will work on other chargers, too? > > ABI can never be removed or modified later. So should be really careful before adding it. > > Is /sys considered ABI? Yes. > User space developers are always reminded not to rely on /sys nodes. No. 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 linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
