From patchwork Thu Aug 29 09:24:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Sylwester Nawrocki/Kernel \\(PLT\\) /SRPOL/Staff Engineer/Samsung Electronics" X-Patchwork-Id: 2851183 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4485E9F2F4 for ; Thu, 29 Aug 2013 09:28:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3488E202CF for ; Thu, 29 Aug 2013 09:28:41 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EA184201D5 for ; Thu, 29 Aug 2013 09:28:39 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEyWq-0004bM-WD; Thu, 29 Aug 2013 09:28:37 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEyWo-0005Wj-Vz; Thu, 29 Aug 2013 09:28:35 +0000 Received: from mailout4.samsung.com ([203.254.224.34]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEyWk-0005Ti-Sy for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2013 09:28:31 +0000 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout4.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MSA005QJCYPKIP0@mailout4.samsung.com> for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2013 18:28:01 +0900 (KST) X-AuditID: cbfee61b-b7f776d0000016c8-37-521f1421ba6c Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm2.samsung.com (EPCPMTA) with SMTP id 04.C6.05832.1241F125; Thu, 29 Aug 2013 18:28:01 +0900 (KST) Received: from amdc1344.digital.local ([106.116.147.32]) by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MSA00IQYCT4W430@mmp2.samsung.com>; Thu, 29 Aug 2013 18:28:01 +0900 (KST) From: Sylwester Nawrocki To: linux-media@vger.kernel.org Subject: [RESEND PATCH v2 2/7] V4L: s5k6a3: Add DT binding documentation Date: Thu, 29 Aug 2013 11:24:33 +0200 Message-id: <1377768278-15391-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1377768278-15391-1-git-send-email-s.nawrocki@samsung.com> References: <1377768278-15391-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrHLMWRmVeSWpSXmKPExsVy+t9jQV1FEfkgg+/rBC1urTvHavHx1G1W i/lHgKz3G+cxWfS/WchqcWryMyaLs01v2C06Jy5ht9j0+BqrRc+GrawWM87vY7JYev0ik8XT CRfZLCZMX8ticXjFASaLw2/aWS3O7F/JZvHqYBuLxfoZr1kchD3WzFvD6LHg8xV2j8t9vUwe Hz7GeczumMnqcfjrQhaPO9f2sHlsXlLv0bdlFaPH501yHhvnhnqc+vqZPYAnissmJTUnsyy1 SN8ugStj8eUG1oIt0hX9k+YxNjBeEOti5OSQEDCROLXhMAuELSZx4d56NhBbSGA6o8TsRg4I u4NJouloMIjNJmAo0Xu0jxHEFhGQl3jSewOonouDWeAxs8S85qdgzcICHhJbjh8FK2IRUJV4 u28KmM0r4Cbx+8VZ9i5GDqBlChJzJtmAhDkF3CU2TzvIDrHLTWL/0u3sExh5FzAyrGIUTS1I LihOSs810itOzC0uzUvXS87P3cQIjoVn0jsYVzVYHGIU4GBU4uGN+C0bJMSaWFZcmXuIUYKD WUmE9y2nfJAQb0piZVVqUX58UWlOavEhRmkOFiVx3oOt1oFCAumJJanZqakFqUUwWSYOTqkG Rge+tYIZisnCZ738usxmTwr1XMwaIPz56GuliRfm8FzJ7ppr1nZ7oeIyifPlNcrTdjlnZcWc WMy+7PbL4ypbdc9xnTMsNpxwguetN+MpJau0wyWONi6aChcV3gpIuF/csP3TYfmtV6Rky056 B+82CL/rEudY/Dsp/scdl7ba5hubGp5sZGN9qcRSnJFoqMVcVJwIABMRWZ2BAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130829_052831_148974_1B2CA711 X-CRM114-Status: GOOD ( 11.72 ) X-Spam-Score: -9.4 (---------) Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, linux-samsung-soc@vger.kernel.org, mturquette@linaro.org, pawel.moll@arm.com, swarren@wwwdotorg.org, devicetree@vger.kernel.org, t.figa@samsung.com, rob.herring@calxeda.com, hverkuil@xs4all.nl, a.hajda@samsung.com, kyungmin.park@samsung.com, sakari.ailus@iki.fi, laurent.pinchart@ideasonboard.com, Sylwester Nawrocki , galak@codeaurora.org, g.liakhovetski@gmx.de, arun.kk@samsung.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds binding documentation for the Samsung S5K6A3(YX) raw image sensor. Signed-off-by: Sylwester Nawrocki Signed-off-by: Kyungmin Park --- The binding of this sensors shows some issue in the generic video-interfaces binding. Namely The video bus type (serial MIPI CSI-2, parallel ITU-R BT.656, etc.) is being determined by the binding parser (v4l2-of.c) depending on what properties are found in an enddpoint node. Please have a look at the data-lanes property description. The sensor supports MIPI CSI-2 and SMIA CCP2 interfaces which both use one data lane. One data lane is everything this sensors supports. During our discussions on the generic bidings in the past I proposed to introduce a property in the endpoint node that would indicate what bus type (standard/protocol) is used, e.g. MIPI CSI-2, ITU-R BT.656, SMIA CCP2, etc. It was argued though that we can well determine bus type based on properties found in the endpoint node. So now in case of this sensor I'm not sure how it can be differentiated whether MIPI CSI-2 or CCP2 bus is used. There is no CCP2 specific generic properties yet. Anyway I'm not really happy there is no property like bus_type that would clearly indicate what data bus type is used. Then would would for instance not specify "data-lanes" in endpoint node just to differentiate between MIPI CSI-2 and the parallel busses. The main issue for this particular binding is that even with data-lanes = <1>; it is still impossible to figure out whether MIPI CSI-2 or SMIA CCP2 data bus is used. So how about introducing, e.g. a string type "bus_type" common property ? I'm considering starting a separate thread for discussing this. --- .../devicetree/bindings/media/samsung-s5k6a3.txt | 31 ++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Documentation/devicetree/bindings/media/samsung-s5k6a3.txt -- 1.7.9.5 diff --git a/Documentation/devicetree/bindings/media/samsung-s5k6a3.txt b/Documentation/devicetree/bindings/media/samsung-s5k6a3.txt new file mode 100644 index 0000000..a51fbe8 --- /dev/null +++ b/Documentation/devicetree/bindings/media/samsung-s5k6a3.txt @@ -0,0 +1,31 @@ +Samsung S5K6A3(YX) raw image sensor +--------------------------------- + +S5K6A3YX is a raw image sensor with MIPI CSI-2 and CCP2 image data interfaces +and CCI (I2C compatible) control bus. + +Required properties: + +- compatible : "samsung,s5k6a3yx"; +- reg : I2C slave address of the sensor; +- svdda-supply : core voltage supply; +- svddio-supply : I/O voltage supply; +- gpios : specifier of a GPIO connected to the RESET pin; +- clocks : should contain the sensor's EXTCLK clock specifier, from + the common clock bindings. +- clock-names : should contain "extclk" entry; + +Optional properties: + +- clock-frequency : the frequency at which the "extclk" clock should be + configured to operate, in Hz; if this property is not + specified default 24 MHz value will be used. + +The common video interfaces bindings (see video-interfaces.txt) should be +used to specify link to the image data receiver. The S5K6A3(YX) device +node should contain one 'port' child node with an 'endpoint' subnode. + +Following properties are valid for the endpoint node: + +- data-lanes : (optional) specifies MIPI CSI-2 data lanes as covered in + video-interfaces.txt. The sensor supports only one data lane.