From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from out20-97.mail.aliyun.com ([115.124.20.97]:47945 "EHLO out20-97.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729827AbeKWSog (ORCPT ); Fri, 23 Nov 2018 13:44:36 -0500 Date: Fri, 23 Nov 2018 16:01:17 +0800 From: Yong To: jacopo mondi Cc: Laurent Pinchart , Maxime Ripard , Mauro Carvalho Chehab , Rob Herring , Mark Rutland , Chen-Yu Tsai , Greg Kroah-Hartman , "David S. Miller" , Andrew Morton , Arnd Bergmann , Hans Verkuil , Geert Uytterhoeven , Neil Armstrong , Philipp Zabel , Jacopo Mondi , Thomas Gleixner , Todor Tomov , linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com, Sakari Ailus Subject: Re: [PATCH v12 1/2] dt-bindings: media: Add Allwinner V3s Camera Sensor Interface (CSI) Message-Id: <20181123160117.7eed41aac3e7e31e4e6d98be@magewell.com> In-Reply-To: <20181123074514.GB6788@w540> References: <1540887143-27904-1-git-send-email-yong.deng@magewell.com> <308184907.pMD7ZDI2dr@avalon> <20181123074514.GB6788@w540> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi jacopo, On Fri, 23 Nov 2018 08:45:14 +0100 jacopo mondi wrote: > Hi Yong, > > On Tue, Oct 30, 2018 at 03:06:24PM +0200, Laurent Pinchart wrote: > > Hi Yong, > > > > Thank you for the patch. > > > > On Tuesday, 30 October 2018 10:12:23 EET Yong Deng wrote: > > > Add binding documentation for Allwinner V3s CSI. > > > > > > Acked-by: Maxime Ripard > > > Acked-by: Sakari Ailus > > > Reviewed-by: Rob Herring > > > Signed-off-by: Yong Deng > > > > Reviewed-by: Laurent Pinchart > > > > > --- > > > .../devicetree/bindings/media/sun6i-csi.txt | 56 +++++++++++++++++++ > > > 1 file changed, 56 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/media/sun6i-csi.txt > > > > > > diff --git a/Documentation/devicetree/bindings/media/sun6i-csi.txt > > > b/Documentation/devicetree/bindings/media/sun6i-csi.txt new file mode > > > 100644 > > > index 000000000000..443e18c181b3 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/media/sun6i-csi.txt > > > @@ -0,0 +1,56 @@ > > > +Allwinner V3s Camera Sensor Interface > > > +------------------------------------- > > > + > > > +Allwinner V3s SoC features a CSI module(CSI1) with parallel interface. > > > + > > > +Required properties: > > > + - compatible: value must be "allwinner,sun8i-v3s-csi" > > > + - reg: base address and size of the memory-mapped region. > > > + - interrupts: interrupt associated to this IP > > > + - clocks: phandles to the clocks feeding the CSI > > > + * bus: the CSI interface clock > > > + * mod: the CSI module clock > > > + * ram: the CSI DRAM clock > > > + - clock-names: the clock names mentioned above > > > + - resets: phandles to the reset line driving the CSI > > > + > > > +The CSI node should contain one 'port' child node with one child 'endpoint' > > > +node, according to the bindings defined in > > > +Documentation/devicetree/bindings/media/video-interfaces.txt. > > > + > > > +Endpoint node properties for CSI > > > +--------------------------------- > > > +See the video-interfaces.txt for a detailed description of these > > > properties. +- remote-endpoint : (required) a phandle to the bus receiver's > > > endpoint + node > > > +- bus-width: : (required) must be 8, 10, 12 or 16 > > > +- pclk-sample : (optional) (default: sample on falling edge) > > > +- hsync-active : (required; parallel-only) > > > +- vsync-active : (required; parallel-only) > > > + > > > +Example: > > > + > > > +csi1: csi@1cb4000 { > > > + compatible = "allwinner,sun8i-v3s-csi"; > > > + reg = <0x01cb4000 0x1000>; > > > + interrupts = ; > > > + clocks = <&ccu CLK_BUS_CSI>, > > > + <&ccu CLK_CSI1_SCLK>, > > > + <&ccu CLK_DRAM_CSI>; > > > + clock-names = "bus", "mod", "ram"; > > > + resets = <&ccu RST_BUS_CSI>; > > > + > > > + port { > > > + /* Parallel bus endpoint */ > > > + csi1_ep: endpoint { > > > + remote-endpoint = <&adv7611_ep>; > > > + bus-width = <16>; > > > + > > > + /* If hsync-active/vsync-active are missing, > > > + embedded BT.656 sync is used */ > > Am I confused? The properties description defines [v|h]sync-active as > required, but the example reports that they can be omitted to use > BT.656 synchronization. > > Which one of the following is correct? > 1) [h|v]sync-active are mandatory: no BT.656 support can be selected. > 2) [h|v]sync-active are optional, and if not specified BT.656 is > selected. > 3) I am confused. > hsync-active : (required; parallel-only) vsync-active : (required; parallel-only) Here, parallel means seperate sync signal, BT.656 means embedded sync signal. Kernel use these two properties to detect if the bus type is parallel or Bt656. So [h|v]sync-active are mandatory only if your bus type is parallel and must not be specified if your bus type is Bt656. Thanks, Yong