From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B4AFC32750 for ; Tue, 13 Aug 2019 13:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1DD120840 for ; Tue, 13 Aug 2019 13:52:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Jm8wdiOc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729324AbfHMNwU (ORCPT ); Tue, 13 Aug 2019 09:52:20 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:47018 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729190AbfHMNwU (ORCPT ); Tue, 13 Aug 2019 09:52:20 -0400 Received: by mail-pg1-f196.google.com with SMTP id w3so14094875pgt.13 for ; Tue, 13 Aug 2019 06:52:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4omLmk4w6GxhJ6Ep/AGChVMuZmOFfkXmdaJYpOvWVdk=; b=Jm8wdiOchfcFJ0gRIk1GejkC9wyb0VHkwgGVXz8gKdqL7fzLdNe4X+BSaGG9GuV7hq 7sD0rsng093Rsmzie0SdLHRA90thFE9fYj9WOv0ACjtbPytWctwLPNobjvwDlDrUm4jM +RiB/SkxEIKpmhyQWtb2ylSHLydV8aBHuQApwmN8zntmaCpdalFNBJkSWHshpYyVFOaE Qxc6xffuXBWRbS4E3gyJNLpoMCzlVb7s7hqB5moABRoHMHcPlrO7/sTM4WZowUZ3rGWX ZoYV4s/si/3dn7P9hJev1D9DePTX2DxnvqcyFilWTIfI+RaWWt2/x4YIohOqR7cPbIrn sc4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=4omLmk4w6GxhJ6Ep/AGChVMuZmOFfkXmdaJYpOvWVdk=; b=W/BEAWuLPcoWDlMC4NJMJ6R29drIe9XZYMnZ27t339H82KE2UHS7zdFi67oF/ISGXE GxKne/b3iC6C9wpowt1NVV5J7cxPsrrO1f5SBDTmxn5YQv+ZWvXjR2bDDzYq7a8N/xqF J+YddqEoXU19sOM6n3UNVUGclrWasxRnTx/ZTQM1R6Nd7ENvAEugXnEzIn7WWJ049qg1 WcHFiURTP5UMjiatk+U7tsSjeOdLOieOV6mcbhawz9mjQ/zmdn0hWUfvtE7tEWFtXnrr VkEI5JoA1/8U2JxnQULPcG0VvQFv9Y4PhXhN3Ru4HyEoBxpUAdZnoKVSgyhaMDxdbhwV hLCg== X-Gm-Message-State: APjAAAW8gxHzI6srS6Z4jcMH6y0omkAP1Dm/eY0jXUOkOCAznHkyooYP e2f1ZKry1hepsBFsVgUUdycg X-Google-Smtp-Source: APXvYqwav0H6AVbnE2BwPov0OYBYEHoA+VkHR9bqs+s/y71GBF2NtI/p4j6/PJKhz+s8rgdAUXLynw== X-Received: by 2002:aa7:8b52:: with SMTP id i18mr41768736pfd.194.1565704339044; Tue, 13 Aug 2019 06:52:19 -0700 (PDT) Received: from Mani-XPS-13-9360 ([2409:4072:649c:6ce0:9d44:669c:5d6c:bc5f]) by smtp.gmail.com with ESMTPSA id j9sm16595539pfe.103.2019.08.13.06.52.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 13 Aug 2019 06:52:18 -0700 (PDT) Date: Tue, 13 Aug 2019 19:22:09 +0530 From: Manivannan Sadhasivam To: Sakari Ailus Cc: mchehab@kernel.org, robh+dt@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, c.barrett@framos.com, a.brela@framos.com Subject: Re: [PATCH v2 1/3] dt-bindings: media: i2c: Add IMX290 CMOS sensor binding Message-ID: <20190813135209.GA30945@Mani-XPS-13-9360> References: <20190806130938.19916-1-manivannan.sadhasivam@linaro.org> <20190806130938.19916-2-manivannan.sadhasivam@linaro.org> <20190813094526.GG835@valkosipuli.retiisi.org.uk> <20190813113358.GA28877@Mani-XPS-13-9360> <20190813114643.GA2527@valkosipuli.retiisi.org.uk> <20190813121400.GA29378@Mani-XPS-13-9360> <20190813122212.GE2527@valkosipuli.retiisi.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190813122212.GE2527@valkosipuli.retiisi.org.uk> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sakari, On Tue, Aug 13, 2019 at 03:22:12PM +0300, Sakari Ailus wrote: > Hi Manivannan, > > On Tue, Aug 13, 2019 at 05:44:00PM +0530, Manivannan Sadhasivam wrote: > > Hi Sakari, > > > > On Tue, Aug 13, 2019 at 02:46:43PM +0300, Sakari Ailus wrote: > > > Hi Manivannan, > > > > > > On Tue, Aug 13, 2019 at 05:03:58PM +0530, Manivannan Sadhasivam wrote: > > > > Hi Sakari, > > > > > > > > Thanks for the review! > > > > > > > > On Tue, Aug 13, 2019 at 12:45:26PM +0300, Sakari Ailus wrote: > > > > > Hi Manivannan, > > > > > > > > > > On Tue, Aug 06, 2019 at 06:39:36PM +0530, Manivannan Sadhasivam wrote: > > > > > > Add devicetree binding for IMX290 CMOS image sensor. > > > > > > > > > > > > Signed-off-by: Manivannan Sadhasivam > > > > > > Reviewed-by: Rob Herring > > > > > > --- > > > > > > .../devicetree/bindings/media/i2c/imx290.txt | 51 +++++++++++++++++++ > > > > > > 1 file changed, 51 insertions(+) > > > > > > create mode 100644 Documentation/devicetree/bindings/media/i2c/imx290.txt > > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/media/i2c/imx290.txt b/Documentation/devicetree/bindings/media/i2c/imx290.txt > > > > > > new file mode 100644 > > > > > > index 000000000000..7535b5b5b24b > > > > > > --- /dev/null > > > > > > +++ b/Documentation/devicetree/bindings/media/i2c/imx290.txt > > > > > > @@ -0,0 +1,51 @@ > > > > > > +* Sony IMX290 1/2.8-Inch CMOS Image Sensor > > > > > > + > > > > > > +The Sony IMX290 is a 1/2.8-Inch CMOS Solid-state image sensor with > > > > > > +Square Pixel for Color Cameras. It is programmable through I2C and 4-wire > > > > > > +interfaces. The sensor output is available via CMOS logic parallel SDR output, > > > > > > +Low voltage LVDS DDR output and CSI-2 serial data output. > > > > > > > > > > If there are three to choose from, then you should specify which one is in > > > > > use. Given that I think chances remain slim we'd add support for the other > > > > > two (it's certainly not ruled out though), CSI-2 could be the default. But > > > > > this needs to be documented. > > > > > > > > > > > > > Hmm... I'm not sure here. Bindings should describe the hardware and not the > > > > limitations of the driver. Here as you said, the sensor can output frames > > > > in 3 different modes/formats but the driver only supports CSI2. I can add a > > > > note in the driver but not sure whether dt-binding is the right place or not! > > > > > > I guess alternatively you could document the necessary bindings for the > > > other two busses. > > > > > > But what I'm saying here is that it's highly unlikely they'll be ever > > > needed, and it'd be mostly a waste of time to implement that. (That said, I > > > have nothing against the use of these busses, but I've never seen anyone > > > using them.) Many other devices use defaults for more contentious settings. > > > > > > > Agree with you but my question was, whether I could document the supported > > mode in bindings or not! I have seen comments from Rob in the past that the > > binding should not document the limitations of the driver. But anyway, one > > can infer from the current binding that only CSI2 is supported for now, it's > > just stating it explicitly makes me doubtful! > > I think it could be e.g.: > > The CSI-2 bus is the default. No bindings have been defined for the other > busses. > Ack. > ... > > > > > > I suppose you can't change the lane order, so clock-lanes is redundant > > > > > (don't use it in the example) and data-lanes should be monotonically > > > > > incrementing series from 1 to 4. > > > > > > > > > > > > > We can change the order and the example here illustrates how it has been > > > > wired in FRAMOS module. If I change the lane order like you said, it won't > > > > work. > > > > > > I highly doubt that. Neither the driver nor the sensor uses the lane > > > ordering information. > > > > > > > Agree but CSI2 host will need this informtion, right? Please correct me if > > I'm wrong! > > The CSI-2 receiver may need that configuration, but it's not addressed by a > sensor's binding documentation (it's configured in the endpoint on the > receiver's side). > Yes but I thought that documenting the sensor lane configuration based on one example implementation might help interfacing w/ different hosts. Anyway, to be host agnostic, I can drop the clock lane and make data lane start from 1 as you suggested. Thanks, Mani > -- > Sakari Ailus