From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olof Johansson Subject: Re: [RFC PATCH v2 00/13] arm/tegra: Initialize GPIO & pinmux from DT Date: Mon, 22 Aug 2011 15:56:55 -0700 Message-ID: References: <1313440100-17131-1-git-send-email-swarren@nvidia.com> <74CDBE0F657A3D45AFBB94109FB122FF04B24A3687@HQMAIL01.nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <74CDBE0F657A3D45AFBB94109FB122FF04B24A3687-C7FfzLzN0UxDw2glCA4ptUEOCMrvLtNR@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Stephen Warren Cc: Grant Likely , Colin Cross , Erik Gilling , Russell King , Arnd Bergmann , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Belisko Marek , Jamie Iles , Shawn Guo , Sergei Shtylyov List-Id: devicetree@vger.kernel.org On Mon, Aug 22, 2011 at 12:56 PM, Stephen Warren w= rote: > Stephen Warren wrote at Monday, August 15, 2011 2:28 PM: >> ... >> This patch modifies Tegra's device tree support to remove the depend= ency >> on harmony_pinmux_init(), thus making it completely board-independen= t. > > I had the good fortune of meeting Grant at LinuxCon last week and tal= ked > through this patchset a little (thanks!) > > The message I got from Grant was that the patches are basically OK. H= e > did have a couple of concerns: > > * Does this cause the compiled DTB to blow up in size. > > The DTB goes from ~3-4K to ~8-9K with these patches added. While that > is a large % increase, Grant said that as an absolute value, that siz= e > shouldn't be an issue. Agreed, especially if compared with the size of the current in-kernel t= able. > * There's lots of repetition in the .dts representation; can this be = improved? > [...] > meaningless-name { // typically would just use the pin name > =A0 =A0pins =3D "ld0", "ld1", "ld2", ...; > =A0 =A0nvidia,function =3D "displaya"; > =A0 =A0nvidia,pull-down; > }; That sounds quite close to what I was thinking about earlier (with s/meaningless-name/displaya/ in the above example). > * We also briefly discussed that dtc could be modified to support sym= bolic > constants, so we could use named integers for the function names (per= haps > pin names too). I'll look into how easy it is to modify dtc for this. That'd be useful, I think -- there's still the whole issue of the same pin function being at different mux locations on different pin groups, so an integer representation might not work. > I'll look into implementing these enhancements, and others discussed = in > this email thread, and repost. Cool. -Olof