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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 A0D08C433DF for ; Mon, 19 Oct 2020 08:28:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C5E82225F for ; Mon, 19 Oct 2020 08:28:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728968AbgJSI2H (ORCPT ); Mon, 19 Oct 2020 04:28:07 -0400 Received: from mga07.intel.com ([134.134.136.100]:52560 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728871AbgJSI2G (ORCPT ); Mon, 19 Oct 2020 04:28:06 -0400 IronPort-SDR: yWQ7vYjw0qCNUgwvPC78QSpYrVfymS3gj2ew2vnhaslQ+7Q70XQWP0BtM3NuwQw4kCXBlpKFxU XZO9aAdZdL9A== X-IronPort-AV: E=McAfee;i="6000,8403,9778"; a="231181566" X-IronPort-AV: E=Sophos;i="5.77,394,1596524400"; d="scan'208";a="231181566" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Oct 2020 01:28:05 -0700 IronPort-SDR: 7hd6gBsRojzneDl5TKwHIK6LJCq55SCXURVXu2vXcJY3K50M2ynAVZ8ttNVMi6CtTXtEFnN//z AAYBPnh1EGkw== X-IronPort-AV: E=Sophos;i="5.77,394,1596524400"; d="scan'208";a="352912315" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Oct 2020 01:28:01 -0700 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id 7EB5D206F1; Mon, 19 Oct 2020 11:27:59 +0300 (EEST) Date: Mon, 19 Oct 2020 11:27:59 +0300 From: Sakari Ailus To: Tomasz Figa Cc: Dongchun Zhu , Mauro Carvalho Chehab , Andy Shevchenko , Rob Herring , Mark Rutland , Nicolas Boichat , Matthias Brugger , Cao Bing Bu , srv_heupstream , "moderated list:ARM/Mediatek SoC support" , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Sj Huang , Linux Media Mailing List , linux-devicetree , Louis Kuo , Shengnan Wang =?utf-8?B?KOeOi+Wco+eUtyk=?= Subject: Re: [PATCH v15 1/2] media: dt-bindings: media: i2c: Document OV02A10 bindings Message-ID: <20201019082759.GL13341@paasikivi.fi.intel.com> References: <20201013130503.2412-1-dongchun.zhu@mediatek.com> <20201013130503.2412-2-dongchun.zhu@mediatek.com> <20201013161938.GE13341@paasikivi.fi.intel.com> <1602641418.4733.80.camel@mhfsdcap03> <20201014083139.GG13341@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Wed, Oct 14, 2020 at 01:48:00PM +0200, Tomasz Figa wrote: > On Wed, Oct 14, 2020 at 10:31 AM Sakari Ailus > wrote: > > > > On Wed, Oct 14, 2020 at 10:10:18AM +0800, Dongchun Zhu wrote: > > > Hello Sakari, > > > > > > Thanks for your timely review. > > > > > > On Tue, 2020-10-13 at 19:19 +0300, Sakari Ailus wrote: > > > > Hi Dongchun, > > > > > > > > On Tue, Oct 13, 2020 at 09:05:02PM +0800, Dongchun Zhu wrote: > > > > > Add YAML device tree binding for OV02A10 CMOS image sensor, and the > > > > > relevant MAINTAINERS entries. > > > > > > > > > > Signed-off-by: Dongchun Zhu > > > > > --- > > > > > .../bindings/media/i2c/ovti,ov02a10.yaml | 162 +++++++++++++++++++++ > > > > > MAINTAINERS | 7 + > > > > > 2 files changed, 169 insertions(+) > > > > > create mode 100644 Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml > > > > > > > > > > > [snip]... > > > > > > > > + ovti,mipi-clock-voltage: > > > > > + description: > > > > > + An array of 2-tuples items, and each item consists of link frequency and > > > > > + MIPI clock voltage unit like . Clock voltage unit is > > > > > + dependent upon link speed, indicating MIPI transmission speed select that > > > > > + controls D-PHY timing setting by adjusting MIPI clock voltage to improve > > > > > + the clock driver capability. > > > > > + $ref: "/schemas/types.yaml#/definitions/uint32-array" > > > > > + minItems: 2 > > > > > + default: [390000, 4] > > > > > > > > Why do you have the link frequency here as well? > > > > > > > > In principle this does belong to the endpoint as link frequencies are > > > > specific to that, but I don't mind; there's just a single port anyway. > > > > > > > > > > This is an optional property which we model as an array of > > clock voltage> pairs. An example to have all link speeds up to 390MHz > > > use the value 4 for current driver. If one wants to select different > > > voltage for different link, they could do so as well. > > > > If you think you'd need that, then you need to put this to the endpoint. > > The mipi-clock-voltage property is not a property of the endpoint. The > link frequency there does not set the link frequency - it only > specifies which link frequency the given voltage should be used for. If it is not bound to the endpoint --- that specifies the properties of the link --- then you could just put it to the driver, couldn't you? But earlier on, we established that this is specific to a given board, or a given link. Endpoints are used to describe connections that a device may have to other devices. Therefore their properties are different. The graph bindings allow for several endpoints on a single physical port, some may be disabled in that case. This is admittedly mostly done with CSI-2 receivers. Either way, putting this property to the device may affect how DT source is arranged for boards that have this device. Any similar configuration on other devices with multiple transmitters or receivers would be in endpoints anyway --- because they have to, so I don't see why bindings for this device should be different. If you put it to endpoint, the driver also doesn't need to match the link frequencies in kHz and Hz between the two properties, but just use the same index for both. -- Sakari Ailus