On Sat, 30 Nov 2013 12:02:02 +0000, Jonathan Cameron wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 11/25/13 09:40, Maxime Ripard wrote: > > Hi Jonathan, > > > > On Sun, Nov 24, 2013 at 09:00:49PM +0000, Jonathan Cameron wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > >> > >> On 11/21/13 13:14, Maxime Ripard wrote: > >>> Hi Denis, > >>> > >>> On Thu, Nov 21, 2013 at 12:41:24PM +0100, Denis CIOCCA wrote: > >>>> only one point: it's possible to use the same names with DT? (using _ instead of -) > >>> > >>> Yes, it is, but only for i2c as far as I'm aware, and usually the DT compatibles are with - as a separator (I > >>> looked into the ePAPR, but couldn't get any explanations or requirements on this, even though it's used in all > >>> of their examples) > >> > >> In other discussions, where the defacto i2c device tree bindings have been followed, the conclusion has been that > >> to change to a - from _ would result in userspace ABI changes, so whilst no one wants _ the discussion has > >> concluded we can't really avoid it. > > > > What kind of userspace ABI changes are we talking about? > IIRC: > > i2c has a generic binding that matches to the name bit of the i2c_device_id > array. That is then exported in sysfs. There are quite a lot of instances > of underscores out there in these names. Thus unforutnately they can't > be changed without possibly breaking userspace. Typically those same names > are also output by IIO though obviously we could keep that the same whilst > changing the dt binding. > > Also the i2c binding allows binding after dropping the vendor prefix which > is even more 'interesting'. See of_modialias_node in drivers/of/base.c > > I'd therefore argue in favour of just leaving the underscores in existing > drivers as a nasty bit of legacy and doing our best to not introduce any > new ones! I don't know what is the problem with underscores, but please note that hwmon i2c devices are NOT allowed to have dashes in their name because that would break libsensors. -- Jean Delvare -- 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
