From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Sverdlin Subject: Re: [PATCH v2] of: i2c: Add idle-disconnect DT property to PCA954x mux driver Date: Thu, 15 Jan 2015 14:35:02 +0100 Message-ID: <54B7C206.8030809@nsn.com> References: <5494599A.8050803@nsn.com> <20150115123237.GC2549@katana> <54B7BBF5.4010001@nsn.com> <20150115131935.GE2549@katana> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150115131935.GE2549@katana> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ext Wolfram Sang Cc: jdelvare-l3A5Bk7waGM@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Laurent Pinchart , Rob Herring , grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, Lawnick Michael 61283229 , Maxime Ripard , Stephen Warren List-Id: devicetree@vger.kernel.org Hi Wolfram, On 15/01/15 14:19, ext Wolfram Sang 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); you are right, thanks for the hint :) I'll prepare v3... -- Best regards, Alexander Sverdlin.