From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4F677304.7020801@freescale.com> Date: Mon, 19 Mar 2012 12:55:16 -0500 From: Scott Wood MIME-Version: 1.0 To: Timur Tabi Subject: Re: [PATCH] Device Tree Bindings for Freescale TDM controller References: <1331861451-15427-1-git-send-email-poonam.aggrwal@freescale.com> <4F63868D.1030507@freescale.com> <4F676C9D.2070301@freescale.com> <4F676D9E.6000609@freescale.com> In-Reply-To: <4F676D9E.6000609@freescale.com> Content-Type: text/plain; charset="ISO-8859-1" Cc: Wood Scott-B07421 , "devicetree-discuss@lists.ozlabs.org" , Aggrwal Poonam-B10812 , "linuxppc-dev@lists.ozlabs.org" , Singh Sandeep-B37400 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/19/2012 12:32 PM, Timur Tabi wrote: > Scott Wood wrote: >>>> Scott, are you suggesting that Poonam put a non-zero number in the DTS >>>> for clock-frequency? If so, then I don't think that's a good idea, if >>>> U-Boot will always override it. > >> This is a device tree binding document, not U-Boot specific. It >> describes what Linux (or another OS) can expect to see, not how it gets >> there. > > That doesn't really answer my question. We currently have many properties > that define a clock frequency, and the DTS sets them all to 0, with the > intent of having U-Boot update them. Ideally these trees should be in U-Boot rather than Linux. > Now maybe these should all be > deleted, but it seems that setting them to a non-zero value is wrong, > because it might mislead people into thinking that the property is not > updated by U-Boot. When you see something like this: > > clock-frequency = <0>; > > It's pretty obvious that U-boot will fill it in. You're assuming that this is a guide for writing dts files. If you look at it as a guide for writing Linux code to interpret the device tree, you'd come to the opposite conclusion. I suggested a comment about common boot software behavior (but otherwise show it as Linux would see it) as middle ground. -Scott