From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RESEND] [PATCH v2 2/4] dt-bindings: Add jdi lt070me05000 panel bindings Date: Wed, 24 Aug 2016 13:56:39 +0200 Message-ID: <20160824115639.GC3169@ulmo.ba.sec> References: <1469978126-925-1-git-send-email-simhavcs@gmail.com> <1469978126-925-2-git-send-email-simhavcs@gmail.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1654917929==" Return-path: In-Reply-To: <1469978126-925-2-git-send-email-simhavcs@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Vinay Simha BN Cc: Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list , "open list:DRM PANEL DRIVERS" , Rob Herring , Archit Taneja List-Id: devicetree@vger.kernel.org --===============1654917929== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="oTHb8nViIGeoXxdp" Content-Disposition: inline --oTHb8nViIGeoXxdp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Jul 31, 2016 at 08:45:21PM +0530, Vinay Simha BN wrote: [...] > diff --git a/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt [...] > +- reset-gpios: phandle of gpio for reset line > + This should be 8mA, gpio can be configured using mux, pinctrl, pinctrl-names > + XRES, Reset, Low active > +- enable-gpios: phandle of gpio for enable line > + LED_EN, LED backlight enable, High active This is a little confusing. Shouldn't we rather completely omit any mention of the polarity of these and let the board design handle this? If the reset is low active, then I'd expect that to be reflected in the GPIO specifier of the reset-gpios property, like so: panel@0 { ... reset-gpios = <&tlmm_pinmux 54 GPIO_ACTIVE_LOW>; ... }; With that a driver can simply deal with a high active reset, which it currently doesn't. The problem with the current description is that it is unclear who's to deal with the polarity. In order for this to work properly with the current driver you'll have to specify the GPIO as GPIO_ACTIVE_HIGH, which is not what the binding says it should be. Thierry --oTHb8nViIGeoXxdp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJXvYt3AAoJEN0jrNd/PrOhR+oQAIZGxWGem3RPv4X3UCOk3A7O AOuychUF9nsuh7isT0DOBUYMI9W5sFPGX3yQnX621KdZBsGpOoy219qdIcwCv5wc LLyR2+MCCqgBso4rgSSfds8p5gKuLT/IOR8htjmLdAC6eZZBxfpSEmDifszGPWp7 tcUopG8092zBHOTFddu1QUxlrh3i9DGofF0JyN0I1fEcY5RaHDyKnmOHC+zKTiRh md2KLeG/szMY6Lfw5v+6U+hB00NjNlUr5hZH2glMzEE357SNCoaXGT8FiRLXCLtE HHe6fR3nHQvgia83NvlPwTW77GtgpkZJicT1/LKxUwnT3JI2MqNvLdjbIpeQdSjq +IgtFNMDiRfXbAONCs+mQtRmil2LcakYJhXimjin2kMcO7t7kSaDWzkHQIgbH71O JcKCHo1ogfIA1fZmnUXZFRUYc7sjv/TtyWbny1B6Bx800U2qelvnSgFHd6c7o0XS +rrzTBbQdDsdEleDcSt6PtQhG/loZi0YyEC3ZNt+bRyac/4Cj4R8ZlfTvrwjB/4l S+39FJr9Ou4AML6PR5Y1aXBirjmM4O+zgmGJbhHmy+MQQymGLwxDWbzepGdfKMfp DQR12UnJ0aB0LfvqmN7iPx8/uVclzHo6n0gL1PHjyeftsu4K2E2MWVH25/9AtF3B rUof0jSgDZh/YPoFNX78 =Y2ul -----END PGP SIGNATURE----- --oTHb8nViIGeoXxdp-- --===============1654917929== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============1654917929==-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932892AbcHXL46 (ORCPT ); Wed, 24 Aug 2016 07:56:58 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35131 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753141AbcHXL44 (ORCPT ); Wed, 24 Aug 2016 07:56:56 -0400 Date: Wed, 24 Aug 2016 13:56:39 +0200 From: Thierry Reding To: Vinay Simha BN Cc: Archit Taneja , John Stultz , Sumit Semwal , David Airlie , Rob Herring , Mark Rutland , "open list:DRM PANEL DRIVERS" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Subject: Re: [RESEND] [PATCH v2 2/4] dt-bindings: Add jdi lt070me05000 panel bindings Message-ID: <20160824115639.GC3169@ulmo.ba.sec> References: <1469978126-925-1-git-send-email-simhavcs@gmail.com> <1469978126-925-2-git-send-email-simhavcs@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="oTHb8nViIGeoXxdp" Content-Disposition: inline In-Reply-To: <1469978126-925-2-git-send-email-simhavcs@gmail.com> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --oTHb8nViIGeoXxdp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Jul 31, 2016 at 08:45:21PM +0530, Vinay Simha BN wrote: [...] > diff --git a/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt [...] > +- reset-gpios: phandle of gpio for reset line > + This should be 8mA, gpio can be configured using mux, pinctrl, pinctrl-names > + XRES, Reset, Low active > +- enable-gpios: phandle of gpio for enable line > + LED_EN, LED backlight enable, High active This is a little confusing. Shouldn't we rather completely omit any mention of the polarity of these and let the board design handle this? If the reset is low active, then I'd expect that to be reflected in the GPIO specifier of the reset-gpios property, like so: panel@0 { ... reset-gpios = <&tlmm_pinmux 54 GPIO_ACTIVE_LOW>; ... }; With that a driver can simply deal with a high active reset, which it currently doesn't. The problem with the current description is that it is unclear who's to deal with the polarity. In order for this to work properly with the current driver you'll have to specify the GPIO as GPIO_ACTIVE_HIGH, which is not what the binding says it should be. Thierry --oTHb8nViIGeoXxdp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJXvYt3AAoJEN0jrNd/PrOhR+oQAIZGxWGem3RPv4X3UCOk3A7O AOuychUF9nsuh7isT0DOBUYMI9W5sFPGX3yQnX621KdZBsGpOoy219qdIcwCv5wc LLyR2+MCCqgBso4rgSSfds8p5gKuLT/IOR8htjmLdAC6eZZBxfpSEmDifszGPWp7 tcUopG8092zBHOTFddu1QUxlrh3i9DGofF0JyN0I1fEcY5RaHDyKnmOHC+zKTiRh md2KLeG/szMY6Lfw5v+6U+hB00NjNlUr5hZH2glMzEE357SNCoaXGT8FiRLXCLtE HHe6fR3nHQvgia83NvlPwTW77GtgpkZJicT1/LKxUwnT3JI2MqNvLdjbIpeQdSjq +IgtFNMDiRfXbAONCs+mQtRmil2LcakYJhXimjin2kMcO7t7kSaDWzkHQIgbH71O JcKCHo1ogfIA1fZmnUXZFRUYc7sjv/TtyWbny1B6Bx800U2qelvnSgFHd6c7o0XS +rrzTBbQdDsdEleDcSt6PtQhG/loZi0YyEC3ZNt+bRyac/4Cj4R8ZlfTvrwjB/4l S+39FJr9Ou4AML6PR5Y1aXBirjmM4O+zgmGJbhHmy+MQQymGLwxDWbzepGdfKMfp DQR12UnJ0aB0LfvqmN7iPx8/uVclzHo6n0gL1PHjyeftsu4K2E2MWVH25/9AtF3B rUof0jSgDZh/YPoFNX78 =Y2ul -----END PGP SIGNATURE----- --oTHb8nViIGeoXxdp--