From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH 3/3] arm64: dts: renesas: draak: Describe HDMI input Date: Mon, 14 May 2018 20:03:18 +0300 Message-ID: <2432779.DoTkMjUeVb@avalon> References: <1526032802-14376-1-git-send-email-jacopo+renesas@jmondi.org> <20180514073520.GA5956@w540> <20180514102326.GG30519@bigcity.dyn.berto.se> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20180514102326.GG30519@bigcity.dyn.berto.se> Sender: linux-kernel-owner@vger.kernel.org To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: jacopo mondi , Jacopo Mondi , horms@verge.net.au, geert@glider.be, magnus.damm@gmail.com, robh+dt@kernel.org, linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Niklas, On Monday, 14 May 2018 13:23:26 EEST Niklas S=F6derlund wrote: > On 2018-05-14 09:39:34 +0200, Jacopo Mondi wrote: > > On Sun, May 13, 2018 at 02:57:55PM +0200, Niklas S=F6derlund wrote: > >> On 2018-05-11 12:00:02 +0200, Jacopo Mondi wrote: > >>> Describe HDMI input connected to VIN4 interface for R-Car D3 Draak > >>> development board. > >>>=20 > >>> Signed-off-by: Jacopo Mondi > >>> --- > >>>=20 > >>> arch/arm64/boot/dts/renesas/r8a77995-draak.dts | 68 ++++++++++++++++= +++ > >>> 1 file changed, 68 insertions(+) > >>>=20 > >>> diff --git a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts > >>> b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts index > >>> d03f194..e0ce462 100644 > >>> --- a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts > >>> +++ b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts [snip] > >>> +&vin4 { > >>> + pinctrl-0 =3D <&vin4_pins>; > >>> + pinctrl-names =3D "default"; > >>> + > >>> + status =3D "okay"; > >>> + > >>> + ports { > >>> + #address-cells =3D <1>; > >>> + #size-cells =3D <0>; > >>> + > >>> + port@0 { > >>> + reg =3D <0>; > >>> + > >>> + vin4_in: endpoint { > >>> + hsync-active =3D <0>; > >>> + vsync-active =3D <0>; > >>=20 > >> Comparing this to the Gen2 bindings some properties are missing, > >>=20 > >> bus-width =3D <24>; > >> pclk-sample =3D <1>; > >> data-active =3D <1>; > >=20 > > The VIN driver does not parse them, so there is no value in having > > them there, if not confusing people as it happened to me reading the > > Gen2 DT. >=20 > I have no objection removing them. Trying to understand why the > description differed from Gen2. >=20 > >> This is not a big deal as the VIN driver don't use these properties so > >> no functional change should come of this but still a difference. > >=20 > > Exactly. > >=20 > > On a side note. I have not seen a way to configure the pixel clock > > sampling level in the interface datasheet. The register used to > > configure synchronism signals polarities is VnDMR2, and there I read > > we can configure HSYNC/VSYNC and CLOCKENB (which is data enable, not > > pixel clock) polarities. Is it configured through some other > > register? >=20 > I have not seen such a register no. >=20 > >> Over all I'm happy with this change but before I add my tag I would li= ke > >> to understand why it differs from the Gen2 configuration for the adv76= 12 > >> properties. > >>=20 > >> Also on a side not it is possible with hardware switches on the board > >> switch the VIN4 source to a completely different pipeline CVBS connect= or > >> -> adv7180 -> VIN4. But I think it's best we keep the HDMI as default = as > >> this seems to be how the boards are shipped. But maybe mentioning this > >> in the commit message would not hurt if you end-up resending the patch. > >=20 > > Oh I see. SW-49 to SW-52 enables the HDMI input, SW53-SW54 CVBS one. > > And actually, reading the 'initial setting of slide switches' in the > > Draak board manual, it turns out that the board default configuration > > is with CVBS input selected... What should we do here? reflect > > defaults in the DT, or prioritize HDMI? >=20 > I feel this is a question for Laurent. My feeling for how we handled > this in other cases is to go with the board default settings. I'm > however sure there are exceptions to the rule. So maybe we should go > with the most useful (what ever that is) configuration? I think I'd go with CVBS as I don't think HDMI would be considered as the m= ost=20 useful configuration here. The Draak board is unlikely to be used by us as = a=20 reference platform to test HDMI capture, is it ? This being said, you can instantiate the adv7612 and HDMI connector in DT,= =20 without connecting them to the VIN. That would make it easy to quickly chan= ge=20 the configuration. > >>> + > >>> + remote-endpoint =3D <&adv7612_out>; > >>> + }; > >>> + }; > >>> + }; > >>> +}; =2D-=20 Regards, Laurent Pinchart