From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 04/14] media: add V4L2 DT binding documentation Date: Mon, 08 Oct 2012 14:00:38 -0600 Message-ID: <507330E6.1010409@wwwdotorg.org> References: <1348754853-28619-1-git-send-email-g.liakhovetski@gmx.de> <1348754853-28619-5-git-send-email-g.liakhovetski@gmx.de> <506AF706.3090003@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-sh-owner@vger.kernel.org To: Guennadi Liakhovetski Cc: Rob Herring , linux-sh@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Mark Brown , Magnus Damm , Hans Verkuil , Laurent Pinchart , Sylwester Nawrocki , linux-media@vger.kernel.org List-Id: devicetree@vger.kernel.org On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote: > On Tue, 2 Oct 2012, Rob Herring wrote: >> On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote: >>> This patch adds a document, describing common V4L2 device tree bindings. >>> diff --git a/Documentation/devicetree/bindings/media/v4l2.txt b/Documentation/devicetree/bindings/media/v4l2.txt >> One other comment below: >> >>> + >>> +General concept >>> +--------------- >>> + >>> +Video pipelines consist of external devices, e.g. camera sensors, controlled >>> +over an I2C, SPI or UART bus, and SoC internal IP blocks, including video DMA >>> +engines and video data processors. >>> + >>> +SoC internal blocks are described by DT nodes, placed similarly to other SoC >>> +blocks. External devices are represented as child nodes of their respective bus >>> +controller nodes, e.g. I2C. >>> + >>> +Data interfaces on all video devices are described by "port" child DT nodes. >>> +Configuration of a port depends on other devices participating in the data >>> +transfer and is described by "link" DT nodes, specified as children of the >>> +"port" nodes: >>> + >>> +/foo { >>> + port@0 { >>> + link@0 { ... }; >>> + link@1 { ... }; >>> + }; >>> + port@1 { ... }; >>> +}; >>> + >>> +If a port can be configured to work with more than one other device on the same >>> +bus, a "link" child DT node must be provided for each of them. If more than one >>> +port is present on a device or more than one link is connected to a port, a >>> +common scheme, using "#address-cells," "#size-cells" and "reg" properties is >>> +used. >>> + >>> +Optional link properties: >>> +- remote: phandle to the other endpoint link DT node. >> >> This name is a little vague. Perhaps "endpoint" would be better. > > "endpoint" can also refer to something local like in USB case. Maybe > rather the description of the "remote" property should be improved? The documentation doesn't show up in all the .dts files that use it; it might be useful to try and make the .dts file as obviously readable as possible. Perhaps "remote-port" or "connected-port" would be sufficiently descriptive. (and yes, I know I'm probably bike-shedding now).