From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92B4ECCA477 for ; Wed, 1 Jun 2022 16:58:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346145AbiFAQ6c (ORCPT ); Wed, 1 Jun 2022 12:58:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345508AbiFAQ6b (ORCPT ); Wed, 1 Jun 2022 12:58:31 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9BAC313B1; Wed, 1 Jun 2022 09:58:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1654102709; x=1685638709; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=gwfhI1oZGrbLaBNHLPYsrYeVXkiVePA59FrgD/UWM4k=; b=hQSW0WHNJloSEkd+fBNg6x0D7FQwMvl1Suv+2dWGOEJpYpQ4CxA42Xq6 qoLY0h8sYiJLuykchPmzBw4+gYxjTAlF250nj05Y6Sd7euk0V/cHXAB6J USNZdcbTYv7I0SthhZyVYkKSAYlfdJAEiE7ZjSloh8pnhwcxl6UOFG2Ef e89nTdPbuy7Fe3HMIJQ0FgtRSb97ffHdc2iLOcalfVu4TkQuQ/m95xlz3 7IdXJbcqq5A/80LgAfsKHGUQVEX2XlhG6FEJO8VsyLjitY9RMiFCF/AQ2 zbxIvvldRj32SY1P6AiaYaVzouCJrhxogRr7A+ry11DDBeMxd+0ZxsMUf A==; X-IronPort-AV: E=McAfee;i="6400,9594,10365"; a="275734842" X-IronPort-AV: E=Sophos;i="5.91,268,1647327600"; d="scan'208";a="275734842" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2022 09:58:29 -0700 X-IronPort-AV: E=Sophos;i="5.91,268,1647327600"; d="scan'208";a="530150781" Received: from smile.fi.intel.com ([10.237.72.54]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2022 09:58:24 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.95) (envelope-from ) id 1nwRfm-000QqW-EX; Wed, 01 Jun 2022 19:58:18 +0300 Date: Wed, 1 Jun 2022 19:58:18 +0300 From: "andriy.shevchenko@linux.intel.com" To: Javier Martinez Canillas Cc: Dominik Kierner , "airlied@linux.ie" , "daniel.vetter@ffwll.ch" , "dri-devel@lists.freedesktop.org" , "geert@linux-m68k.org" , "lee.jones@linaro.org" , "linux-fbdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-pwm@vger.kernel.org" , "maxime@cerno.tech" , "noralf@tronnes.org" , "sam@ravnborg.org" , "thierry.reding@gmail.com" , "tzimmermann@suse.de" , "u.kleine-koenig@pengutronix.de" Subject: Re: [PATCH v6 3/6] drm: Add driver for Solomon SSD130x OLED displays Message-ID: References: <5d817ea54144414aa7865a72694b5811@dh-electronics.com> <536d4700-6f28-176d-7883-5793f5cd7c8e@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <536d4700-6f28-176d-7883-5793f5cd7c8e@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Wed, May 25, 2022 at 09:46:24PM +0200, Javier Martinez Canillas wrote: > On 3/10/22 14:11, Dominik Kierner wrote: ... > > # DRM Mode Configuration via Device Tree > > > > In the old fbdev driver, the display modes are hard-coded, which means > > for every new display configuration, a new patch needs to be mainlined, > > which slows down official Kernel support and > > puts burden on the maintainers. > > Additionally, with the DRM-subsystem supporting height and length > > information, for scaling, this opens up a lot of new combinations. > > The SSD1306 for example, is available in multiple resolutions like > > 128x64 and 96x16 and comes in different sizes per resolution as well. > > Just to name a few: > > * 128x64 0.96" (22x11mm) > > * 128x64 1.3" (30x15mm) > > * 96x16 0.69" (18x3mm) > >> Instead of hard-coding, I would suggest something along the lines of > > of_get_drm_display_mode(). > > The displays won't need to support multiple modes at the same time, > > let alone support for switching between them, > > so the one-time invocation of this expensive function might be worth it. > > maybe a new and simpler function that could be named: > > of_get_drm_display_mode_simple() > > This makes sense to me as well. What about non-OF platforms? Please, do not spread OF-only interfaces, and use fwnode instead. > > Providing a mode could later prove useful for a conversion to > > drm_panel, if that is feasible. > > > > But for a function like this, I have to chicken out. -- With Best Regards, Andy Shevchenko