From mboxrd@z Thu Jan 1 00:00:00 1970 From: jacopo mondi Subject: Re: [RESEND PATCH v5 2/3] dt-bindings: display: atmel: optional video-interface of endpoints Date: Fri, 3 Aug 2018 10:51:43 +0200 Message-ID: <20180803085143.GC4528@w540> References: <20180803072308.14962-1-peda@axentia.se> <20180803072308.14962-3-peda@axentia.se> <20180803081128.GA4528@w540> <6fe3e84e-bd9d-0894-df8b-1b40c0f9477d@axentia.se> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1275557568==" Return-path: In-Reply-To: <6fe3e84e-bd9d-0894-df8b-1b40c0f9477d@axentia.se> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Peter Rosin Cc: Mark Rutland , devicetree@vger.kernel.org, Alexandre Belloni , David Airlie , Jyri Sarha , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Nicolas Ferre , Boris Brezillon , Rob Herring , Jacopo Mondi , Laurent Pinchart , Russell King - ARM Linux , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org --===============1275557568== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="uh9ZiVrAOUUm9fzH" Content-Disposition: inline --uh9ZiVrAOUUm9fzH Content-Type: text/plain; charset=utf-8 Content-Disposition: inline On Fri, Aug 03, 2018 at 10:40:02AM +0200, Peter Rosin wrote: > On 2018-08-03 10:11, jacopo mondi wrote: > > Hi Peter! > > > > On Fri, Aug 03, 2018 at 09:23:07AM +0200, Peter Rosin wrote: > >> With bus-type/bus-width properties in the endpoint nodes, the video- > >> interface of the connection can be specified for cases where the > >> heuristic fails to select the correct output mode. This can happen > >> e.g. if not all RGB pins are routed on the PCB; the driver has no > >> way of knowing this, and needs to be told explicitly. > >> > >> This is critical for the devices that have the "conflicting output > >> formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant > >> RGB bits move around depending on the selected output mode. For > >> devices that do not have the "conflicting output formats" issue > >> (SAMA5D2, SAMA5D4), this is completely irrelevant. > >> > >> Acked-by: Boris Brezillon > >> Reviewed-by: Rob Herring > >> Signed-off-by: Peter Rosin > >> --- > >> .../devicetree/bindings/display/atmel/hlcdc-dc.txt | 26 ++++++++++++++++++++++ > >> 1 file changed, 26 insertions(+) > >> > >> diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> index 82f2acb3d374..9de434a8f523 100644 > >> --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt > >> @@ -15,6 +15,14 @@ Required children nodes: > >> to external devices using the OF graph reprensentation (see ../graph.txt). > >> At least one port node is required. > >> > >> +Optional properties in grandchild nodes: > >> + Any endpoint grandchild node may specify a desired video interface > >> + according to ../../media/video-interfaces.txt, specifically > >> + - bus-type: must be <0>. > > > > Is there any value in specifying this, if it has a fixed value to > > "autodetect"? I understand it's optional, so if nobody else objects, > > feels free to keep it there. > > That's just how media/video-interfaces.txt works. > > bus-type 0 means that other properties describe the bus type. In this > case bus-width is specified, so that means a parallel bus. But bus-width > has no meaning (or may not have) if bus-type is non-zero. But checking > that bus-type for zero in the code seemed like overkill to me since the > driver already knows that it is a parallel bus... > Yeah, I felt like pointing that out since you're not cheking for its value, and that property is only used by v4l2-fwnode to handle some not-that-used-anymore bus as CCP2 is. > TL;DR I'd like to keep it. > Fine with me then. > > > >> + - bus-width: recognized values are <12>, <16>, <18> and <24>, and > >> + override any output mode selection heuristic, forcing "rgb444", > >> + "rgb565", "rgb666" and "rgb888" respectively. > >> + > >> Example: > >> > >> hlcdc: hlcdc@f0030000 { > >> @@ -50,3 +58,21 @@ Example: > >> #pwm-cells = <3>; > >> }; > >> }; > >> + > > > > Two blank lines here. > > > >> + > >> +Example 2: With a video interface override to force rgb565; as above > >> +but with these changes/additions: > >> + > >> + &hlcdc { > >> + hlcdc-display-controller { > >> + pinctrl-names = "default"; > >> + pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>; > >> + > >> + port@0 { > > > > The node has a unit address specified, you're missing a reg = <0> > > property (no big deal, it's an example, but the other one has it) > > > >> + hlcdc_panel_output: endpoint@0 { > > > > Missing reg here too. > > I'll fix those (I think they appeared for the original example after I > wrote the patch). > Ok, then please consider also describing the port@0 node cell sizes too since it has a child endpoint node. Cheers j > Cheers, > Peter > > > Minors apart: > > > > Reviewed-by: Jacopo Mondi > > > > Thanks > > j > > > >> + bus-type = <0>; > >> + bus-width = <16>; > >> + }; > >> + }; > >> + }; > >> + }; > >> -- > >> 2.11.0 > >> > --uh9ZiVrAOUUm9fzH Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJbZBefAAoJEHI0Bo8WoVY8YEAQAK4/Xl3bZx+rmnDsc8c5zudH dsY4OmeO985t/cxZH1P6brYKThwYqMZ70/Xr7GYmhn2v0N6GcjXwOh6k4+rmLMrn lT8OXuaO6DbqTmdQAosnZcdbie9YdpDwnc2xRGZw1jZth+OMw3D7Ue5BiAcGX7lV XNQ8DFufd5rrfWzHVNV5mTbfPx3WA/H8J68B5BFNW+rCzcxSw8Ez2eiPwkc/XOL/ rn7k/jKvzbwDqahyVO7UfQkUrqxM5Uaa/SRMT2Cl4NSiUM6QIVRMJ3nfBwSo6JMw 9nL7EUhLS1AXeGRaiiMssb7I6+SvRISVjwTJhF+D/6CIBTPDIdDrNaxGEY4oYOT/ BRYNhynIks6LDV6UR+SiQ5VjYSbZvvDIvJoUr7es4gEMwDGn5aHUdACGnfFuVEEm urh0IVGpoPtOi3IOCk9C17hCuzuXoBd1n+yN2q07uqx5DTYNnvJMoZKULHDhLC4U vzNDiqbWbackuY5LBFEu3wuCtXuagtQkhGF6Kn24d+419c/5K+fbEDD7Qq/z67ma 43SUy2w6XvqRM5sMjs+E7rFQK60W92XuHIv4DP7s+meuJe14Km6BHnSZNi6QsOMn 7oIGhSujoBY8vYrV+MoKhrg2UccH2DMxTl6RCa5xoeMkGb5GrB4YMlpe4boRM3af f68v4sPv0G9bTYxiXr8R =wH5T -----END PGP SIGNATURE----- --uh9ZiVrAOUUm9fzH-- --===============1275557568== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============1275557568==--