Hi Wolfram, On Thursday 15 January 2015 14:19:35 Wolfram Sang wrote: > On Thu, Jan 15, 2015 at 02:09:09PM +0100, Alexander Sverdlin wrote: > > On 15/01/15 13:32, ext Wolfram Sang wrote: > >> On Fri, Dec 19, 2014 at 06:00:10PM +0100, Alexander Sverdlin wrote: > >>> of: i2c: Add idle-disconnect DT property to PCA954x mux driver > >>> > >>> Add idle-disconnect device tree property to PCA954x mux driver. The new > >>> property forces the multiplexer to disconnect child buses in idle > >>> state. This is used, for example, when there are several multiplexers > >>> on the same bus and the devices on the underlying buses might have > >>> same I2C addresses. > >> > >> Basically OK. Question to DT maintainers: "idle-disconnect", > >> "i2c-mux-idle-disconnect", or is there another existing binding we could > >> use? > >> > >>> At the same time old (and not used in the tree) platform data binding > >>> deselect_on_exit is removed to simplify the implementation. Old binding > >>> has different (per-channel) semantics and doesn't fit well in the new > >>> concept. > >> > >> I'd prefer to keep it. It should be only one || more. It is not really > >> in the way IMO. > > > > It complicates the implementation 3x times :) This is part of our > > discussion with Laurent: > > Does it? I don't want DT and platform_data to behave equally. I just > want to keep being backwards compatible. So, I'd suggest: > > (pdata && pdata->modes[num].deselect_on_exit) || idle_disconnect ? > pca954x_deselect_mux : NULL); > > >> I'm not keen to brake out-of-tree code (if any), but may be it will be > >> decided to drop this per-channel deselect_on_exit, because it's not used > >> at least in the kernel tree... > > I couldn't find a user of the platform_data, at all. But removing > platform_data support is a seperate patch, and deprecating platform_data > is a seperate and general issue IMO. Sure, but it could be a preliminary patch on top of which to add idle- disconnect DT support :-) -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
