From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: Tegra pinmux Device Tree support Date: Wed, 10 Aug 2011 11:23:49 +1000 Message-ID: <20110810012349.GA23511@yookeroo.fritz.box> References: <74CDBE0F657A3D45AFBB94109FB122FF049F17229E@HQMAIL01.nvidia.com> <20110809173428.GB32195@ponder.secretlab.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Olof Johansson Cc: Grant Likely , "Linus Walleij (linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org)" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On Tue, Aug 09, 2011 at 10:44:29AM -0700, Olof Johansson wrote: > On Tue, Aug 9, 2011 at 10:34 AM, Grant Likely wrote: >=20 > > We talked about this a bit at Linaro connect. =A0Outside of the mor= e > > complex runtime-reconfiguration of pin mux, there is a general need > > for arbitrary initialization sequences to registers. =A0Also, prett= y > > much exactly what you need for tegra is needed for imx, omap and ma= ny > > others. =A0The though was, rather than trying to come up with some = kind > > of pinmux-specific binding for pin states, which could end up being > > very verbose if everything was split out into properties, we could > > instead have a binding for register initialization sequences. > > Something like this: > > > > =A0 =A0 =A0 =A0pinmux-initseq =3D ...; > > > > And then add some macros for DTC to make it easier to define things > > like pinmux setup tables. =A0Although the binding above is probably= too > > simple and naive. >=20 > This seems to break the philosophy of what the device tree should do > -- it should describe the hardware so that the driver will know how t= o > program it, not include the code itself? Arguably, yes, although it's a barrier that's been frequently broken by Apple already. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _oth= er_ | _way_ _around_! http://www.ozlabs.org/~dgibson From mboxrd@z Thu Jan 1 00:00:00 1970 From: david@gibson.dropbear.id.au (David Gibson) Date: Wed, 10 Aug 2011 11:23:49 +1000 Subject: Tegra pinmux Device Tree support In-Reply-To: References: <74CDBE0F657A3D45AFBB94109FB122FF049F17229E@HQMAIL01.nvidia.com> <20110809173428.GB32195@ponder.secretlab.ca> Message-ID: <20110810012349.GA23511@yookeroo.fritz.box> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Aug 09, 2011 at 10:44:29AM -0700, Olof Johansson wrote: > On Tue, Aug 9, 2011 at 10:34 AM, Grant Likely wrote: > > > We talked about this a bit at Linaro connect. ?Outside of the more > > complex runtime-reconfiguration of pin mux, there is a general need > > for arbitrary initialization sequences to registers. ?Also, pretty > > much exactly what you need for tegra is needed for imx, omap and many > > others. ?The though was, rather than trying to come up with some kind > > of pinmux-specific binding for pin states, which could end up being > > very verbose if everything was split out into properties, we could > > instead have a binding for register initialization sequences. > > Something like this: > > > > ? ? ? ?pinmux-initseq = ...; > > > > And then add some macros for DTC to make it easier to define things > > like pinmux setup tables. ?Although the binding above is probably too > > simple and naive. > > This seems to break the philosophy of what the device tree should do > -- it should describe the hardware so that the driver will know how to > program it, not include the code itself? Arguably, yes, although it's a barrier that's been frequently broken by Apple already. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson