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=-9.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 4DF98C4346E for ; Tue, 29 Sep 2020 09:48:06 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C91DE20848 for ; Tue, 29 Sep 2020 09:48:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OuTkjTbY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C91DE20848 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gWc4hv7oi7Q3XVKQF20vbo5MFK/oEXwTT3vBs+LNmVA=; b=OuTkjTbY2IOpDIOq2BoZs4CdY 3CNntDPN0kpEm1m1Ipk8V7zWljm8KVILefxLk/09mz7jyuZvsD9i9KD1MM/c+EskyXucL/LwFh0TJ /6AzFIxWU/S/tipT+095m7TLR1YcpScO/1j5P386vgpaXsTkc3ZIs7pkUAGQyryquuAT+XSLtSjnb JExHFSnyk+QtwDm5G1x9nYrG8gx2lS5Y8JYrCU21gdkuBnLps+kt8lH7ZYk8iTPPdVW2F5gwGqH6u HBp8ng1uHUiiovLgpwmhBhIr/cO+YXWFX/H4IVafecdUDylxeMRj1xSnDfYTQX7GfHFORB0xav8PT Hbpu2qRig==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNCDb-0002wK-6h; Tue, 29 Sep 2020 09:46:43 +0000 Received: from mail-ej1-f68.google.com ([209.85.218.68]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kNCDY-0002vo-Qz for linux-arm-kernel@lists.infradead.org; Tue, 29 Sep 2020 09:46:41 +0000 Received: by mail-ej1-f68.google.com with SMTP id h26so3958082ejq.3 for ; Tue, 29 Sep 2020 02:46:40 -0700 (PDT) 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=5nWv42Ih42N2NRVG8MQhIrrPCYfOCsYTrczhveDJBnc=; b=DEO/DIy8q2pXaTREJxFCq9FeLO6kpmg8Y+3t8sktIFjdxPywy850nU3Js6F3eI+Vwi am4YhXj90z5mznzke07HJ+YPuoS6A98a+plFh12NF6kCu788WT1FuWdN88h6HfHuO848 3k88QZ5mUob741fXD0DXvo+q4JavjWvflkgKA6G2uB75V+3EW4MTkfhqIiB5YNkPqQd0 Y9+Fvd1aGEpFGRAr/Ds4a6c+X0ohQ5tKLFl+rRxxs3U/sofTe3n3rwukpGJqkdsW/HLI r4XahC23CJ848Zco3StSJQBxxwwXua6FSWZtauzU35cE9kA+Nr0uZa582CsrtbNe4Lcl TcnA== X-Gm-Message-State: AOAM5324sUy/A2dysHCrSqtA9zDxmObL/WxsipIssBxFYvILUuLyNtJD z2Lkebo/EVdUYQ0M7E7xhHo= X-Google-Smtp-Source: ABdhPJw1hpwhNC3rQ/oGOS8jzFlP0SaAObmpGtctW3hXetAzfkJI/GW1bHdNVmPi10NuZ+Id7P2tZQ== X-Received: by 2002:a17:906:b88e:: with SMTP id hb14mr2840343ejb.543.1601372799559; Tue, 29 Sep 2020 02:46:39 -0700 (PDT) Received: from kozik-lap ([194.230.155.194]) by smtp.googlemail.com with ESMTPSA id x6sm4663845ejf.59.2020.09.29.02.46.37 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 29 Sep 2020 02:46:38 -0700 (PDT) Date: Tue, 29 Sep 2020 11:46:36 +0200 From: Krzysztof Kozlowski To: Sakari Ailus Subject: Re: [PATCH v4 1/4] dt-bindings: media: imx258: add bindings for IMX258 sensor Message-ID: <20200929094636.GA11333@kozik-lap> References: <20200923152129.21736-1-krzk@kernel.org> <20200929091512.GF26842@paasikivi.fi.intel.com> <20200929094046.GH26842@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200929094046.GH26842@paasikivi.fi.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200929_054640_921172_7BB1179C X-CRM114-Status: GOOD ( 29.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Shawn Guo , Sascha Hauer , "linux-kernel@vger.kernel.org" , Rob Herring , NXP Linux Team , Pengutronix Kernel Team , Mauro Carvalho Chehab , Fabio Estevam , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Sep 29, 2020 at 12:40:46PM +0300, Sakari Ailus wrote: > On Tue, Sep 29, 2020 at 11:18:46AM +0200, Krzysztof Kozlowski wrote: > > On Tue, 29 Sep 2020 at 11:15, Sakari Ailus wrote: > > > > > > Hi Krzysztof, > > > > > > On Wed, Sep 23, 2020 at 05:21:26PM +0200, Krzysztof Kozlowski wrote: > > > > Add bindings for the IMX258 camera sensor. The bindings, just like the > > > > driver, are quite limited, e.g. do not support regulator supplies. > > > > > > > > Signed-off-by: Krzysztof Kozlowski > > > > > > > > --- > > > > > > > > Changes since v3: > > > > 1. Document also two lane setup. > > > > > > > > Changes since v2: > > > > 1. Remove clock-frequency, add reset GPIOs, add supplies. > > > > > > Oops. I missed this one. > > > > > > How does the driver know the appropriate clock frequency for the platform > > > if it's not in DT? The sensor supports a range of frequencies, not a single > > > frequency. > > > > > > Could you add clock-frequency back? > > > > Not really, it was removed on Rob's request. The bindings do not > > describe driver's behavior so how the driver gets frequency should not > > be part of the bindings. Also it's not a real problem - the driver > > just calls clk_get_rate(). > > How is the rate determined? I mean, many ISPs or CSI-2 receivers that > provide the clock are also capable of using a variety of frequencies. But > only one can be used on the platform in general. Having "clock-frequency" property in DTS did not solve that. It has no effect on actual frequency. > > Where does it come from if it's not in DT? The frequency is either chosen by consumer (imx258) or pre-assigned from DT, but not with "clock-frequency" property. There are generic properties for this: assigned-clocks, assigned-clock-rates and assigned-clock-parents. These properties should be added to DTS if additionalProperties is false, which is the case here... so I could add them. My DTS anyway does not use them, as the clock is generated internally on a camera board so I don't have a control over it. Best regards, Krzysztof > > Using another frequency generally leads to failure later on as the desired > link frequency likely is not available for a random external clock > frequency. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel