From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guennadi Liakhovetski Subject: Re: [RFC/PATCH 06/13] media: s5p-fimc: Add device tree support for FIMC-LITE Date: Wed, 18 Jul 2012 09:57:34 +0200 (CEST) Message-ID: References: <4FBFE1EC.9060209@samsung.com> <1337975573-27117-1-git-send-email-s.nawrocki@samsung.com> <1337975573-27117-6-git-send-email-s.nawrocki@samsung.com> <5005B51E.20505@gmail.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <5005B51E.20505@gmail.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Sylwester Nawrocki Cc: Sylwester Nawrocki , linux-media@vger.kernel.org, kyungmin.park@samsung.com, m.szyprowski@samsung.com, riverful.kim@samsung.com, sw0312.kim@samsung.com, devicetree-discuss@lists.ozlabs.org, linux-samsung-soc@vger.kernel.org, b.zolnierkie@samsung.com List-Id: devicetree@vger.kernel.org Hi Sylwester On Tue, 17 Jul 2012, Sylwester Nawrocki wrote: > On 07/16/2012 11:15 AM, Guennadi Liakhovetski wrote: > > > --- a/Documentation/devicetree/bindings/camera/soc/samsung-fimc.txt > > > +++ b/Documentation/devicetree/bindings/camera/soc/samsung-fimc.txt > > > @@ -39,6 +39,21 @@ Required properties: > > > depends on the SoC revision. For S5PV210 valid values are: > > > 0...2, for Exynos4x1x: 0...3. > > > > > > + > > > +'fimc-lite' device node > > > +----------------------- > > > + > > > +Required properties: > > > + > > > +- compatible : should be one of: > > > + "samsung,exynos4212-fimc"; > > > + "samsung,exynos4412-fimc"; > > > +- reg : physical base address and size of the device's memory > > > mapped > > > + registers; > > > +- interrupts : should contain FIMC-LITE interrupt; > > > +- cell-index : FIMC-LITE IP instance index; > > > > Same as in an earlier patch - not sure this is needed. > > It is needed for setting up a pipeline of multiple sub-device > within a SoC. As I commented on patch 2/13 I'd like to replace > this with proper entries in the "aliases" node. Some sub-devices > have registers that these indexes need to be directly written to. Aha, so, these are not purely software indices, that you just use to identify your devices, these are actual hardware values? You really have to write, e.g., "1" into a resizer register to connect it to a certain capture engine? Ok, in this case it indeed might make sense to have these values in the DT. Not sure how best to call these properties, or whether aliases is the best solution, but that's already a detail. And btw, if you do decide to keep this as a property, maybe this is one of the cases, where you'd want to mark it with your hardware type, like "fimc,cell-id" or similar? Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/