From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from relay7-d.mail.gandi.net ([217.70.183.200]:51533 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390293AbeKWS4T (ORCPT ); Fri, 23 Nov 2018 13:56:19 -0500 Date: Fri, 23 Nov 2018 09:13:00 +0100 From: jacopo mondi To: Yong 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: <20181123081300.GC6788@w540> References: <1540887143-27904-1-git-send-email-yong.deng@magewell.com> <308184907.pMD7ZDI2dr@avalon> <20181123074514.GB6788@w540> <20181123160117.7eed41aac3e7e31e4e6d98be@magewell.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="y2zxS2PfCDLh6JVG" Content-Disposition: inline In-Reply-To: <20181123160117.7eed41aac3e7e31e4e6d98be@magewell.com> Sender: linux-media-owner@vger.kernel.org List-ID: --y2zxS2PfCDLh6JVG Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Hi Yong, On Fri, Nov 23, 2018 at 04:01:17PM +0800, Yong wrote: > 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. Well, BT.565 sync mode applies to parallel data transmission busses as BT.601 sync mode does... I don't want to bikeshed on terms though, I'm sorry... I would have write here: hsync-active : Required when using explicit HSYNC synchronism signal. Default valuse is "high"/"low". vsync-active : Required when using explicit VSYNC synchronism signal. Default valuse is "high"/"low". When both vsync-active and hsync-active are omitted BT.565 implicit synchronization mode is used. To avoid confusing people already confused as I am :) I got this patch is already in, right? Feel free to ignore my comment or either send an incremental patch if you think it is appropriate. 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