From patchwork Wed Aug 28 15:55:55 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: 2850872 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 831959F485 for ; Wed, 28 Aug 2013 15:58:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 416DE20412 for ; Wed, 28 Aug 2013 15:57:59 +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 D698B203E6 for ; Wed, 28 Aug 2013 15:57:57 +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 1VEi7r-0000YN-MG; Wed, 28 Aug 2013 15:57:43 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEi7h-0001hw-SU; Wed, 28 Aug 2013 15:57:33 +0000 Received: from mailout3.samsung.com ([203.254.224.33]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VEi7P-0001eL-SB for linux-arm-kernel@lists.infradead.org; Wed, 28 Aug 2013 15:57:17 +0000 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MS900BND0AUK420@mailout3.samsung.com> for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2013 00:56:55 +0900 (KST) X-AuditID: cbfee61b-b7f776d0000016c8-c7-521e1dc626d3 Received: from epmmp1.local.host ( [203.254.227.16]) by epcpsbgm2.samsung.com (EPCPMTA) with SMTP id 86.11.05832.6CD1E125; Thu, 29 Aug 2013 00:56:54 +0900 (KST) Received: from amdc1344.digital.local ([106.116.147.32]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MS900LE309EAJB0@mmp1.samsung.com>; Thu, 29 Aug 2013 00:56:54 +0900 (KST) From: Sylwester Nawrocki To: linux-media@vger.kernel.org Subject: [PATCH v2 2/7] V4L: s5k6a3: Add DT binding documentation Date: Wed, 28 Aug 2013 17:55:55 +0200 Message-id: <1377705360-12197-3-git-send-email-s.nawrocki@samsung.com> X-Mailer: git-send-email 1.7.9.5 In-reply-to: <1377705360-12197-1-git-send-email-s.nawrocki@samsung.com> References: <1377705360-12197-1-git-send-email-s.nawrocki@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrJLMWRmVeSWpSXmKPExsVy+t9jAd1jsnJBBhu3W1rcWneO1eLjqdus Fu83zmOyODX5GZPF2aY37BadE5ewW2x6fI3VomfDVlaLpxMuslkcftPOanFm/0o2i/UzXrM4 8Hh8+BjnMbtjJqvH4a8LWTzuXNvD5rF5Sb1H35ZVjB6fN8l5nPr6mT2AI4rLJiU1J7MstUjf LoEr4+f52+wFW6Ur+ifNY2xgvCDWxcjJISFgIrFq/UdGCFtM4sK99WxdjFwcQgKLGCXWfbzI AuF0MEnc39bIDlLFJmAo0Xu0D6xDREBe4knvDbAOZoENTBJ3V9wDKxIWcJR4vOMaC4jNIqAq caj1MFgDr4CbRNuU00xdjBxA6xQk5kyyATE5Bdwl7lyQAKkQAqp4dLuZbQIj7wJGhlWMoqkF yQXFSem5RnrFibnFpXnpesn5uZsYwQH6THoH46oGi0OMAhyMSjy8Eb9lg4RYE8uKK3MPMUpw MCuJ8P4WkQsS4k1JrKxKLcqPLyrNSS0+xCjNwaIkznuw1TpQSCA9sSQ1OzW1ILUIJsvEwSnV wOj40kDEZM6O1f6i0fUlJzpkkqdPEBLqPxypn8kh/cT4gViEBZPsp7InzcWTf+55oJS2635v 7tPZ989vCP56J6n2a7PnizRf1sxneu4XVPvZLhiezVwryh25yTiHX0B7mV/PetveiTGPd8k6 TrPWFdZ9lLySaWrI9zU32+4/3pktaRcZw3UvU4mlOCPRUIu5qDgRAAzzYQlMAgAA X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130828_115716_241914_4A433163 X-CRM114-Status: GOOD ( 11.94 ) X-Spam-Score: -9.4 (---------) Cc: linux-arm-kernel@lists.infradead.org, mturquette@linaro.org, t.figa@samsung.com, hverkuil@xs4all.nl, a.hajda@samsung.com, kyungmin.park@samsung.com, sakari.ailus@iki.fi, laurent.pinchart@ideasonboard.com, Sylwester Nawrocki , 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 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.