From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@linaro.org (Shawn Guo) Date: Tue, 17 Jan 2012 10:32:11 +0800 Subject: [RFC PATCH v3 2/5] pinctrl: add dt binding support for pinmux mappings In-Reply-To: References: <7FE21149F4667147B645348EC605788507F698@039-SN2MPN1-013.039d.mgd.msft.net> <74CDBE0F657A3D45AFBB94109FB122FF177EE39E6B@HQMAIL01.nvidia.com> <20120107135445.GI4790@S2101-09.ap.freescale.net> <74CDBE0F657A3D45AFBB94109FB122FF177EE3A6E5@HQMAIL01.nvidia.com> <20120112033941.GH20968@S2101-09.ap.freescale.net> <74CDBE0F657A3D45AFBB94109FB122FF17801D1DCC@HQMAIL01.nvidia.com> <20120113034558.GA12184@S2101-09.ap.freescale.net> <74CDBE0F657A3D45AFBB94109FB122FF17801D1F9D@HQMAIL01.nvidia.com> <20120114012213.GD1810@S2101-09.ap.freescale.net> Message-ID: <20120117023206.GA11756@S2101-09.ap.freescale.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jan 16, 2012 at 05:08:57PM +0100, Linus Walleij wrote: ... > As you can see none of the text above claims that the group is > about hardware-defined groups or anything like that. The groups > are just that - a group of pins, an abstract concept of a group. Ok, the thing gets clarified. The concept of group is a abstract at software level. It does not necessarily require a pin group defined by raw hardware underneath, which is basically my argument. > It could be drawn i UML even... maybe I'll do that for my > ELC presentation :-) > > Then when we come to pinmux, which is slightly different > involving the definitions of a function and mappings between > functions and one or more pin groups as per above, which is > something completely different and seems to be what you're > discussing here? > > For hardware that does handle pins in groups there are > special functions that can be used in the drivers like > configuring a whole group (which falls back to iterating > over pins if there is no such callback, showing again that > this is a theoretical concept) so if the hardware handles > pins in groups its a good idea to match group definitions > 1-to-1 with these, but for hardware that doesn't there is > some freedom of how to use the groups. > > I don't know if this helps though the discussion here seems > a bit contended :-/ > It does help to me. Thanks, Linus. -- Regards, Shawn