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 582D0C433EF for ; Wed, 2 Feb 2022 08:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245027AbiBBIjA (ORCPT ); Wed, 2 Feb 2022 03:39:00 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:34193 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245039AbiBBIi4 (ORCPT ); Wed, 2 Feb 2022 03:38:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643791135; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IQ96plJnExVz4IofZgZgy11FIOo1veP7nuoBU4KJMcA=; b=BQmHESqj7So+lESTgNlrXx12KcqJ3SGlSnqbUdeIlnOt3tKjzBvXxDV41RnR54R0yfUfJu 06JSlQkc7butqaeEC/TdQ5eYG6XMhfZ5Ywga6YikkPbmvlchYrs9qMwMh2bDRLSn21JkoT /d9U9GsE9K1hS1tBz4jgxYb70LQz5Vc= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-606-V1TOX9n-N9uDNGP3YlDnUQ-1; Wed, 02 Feb 2022 03:38:54 -0500 X-MC-Unique: V1TOX9n-N9uDNGP3YlDnUQ-1 Received: by mail-wm1-f70.google.com with SMTP id c7-20020a1c3507000000b0034a0dfc86aaso3423009wma.6 for ; Wed, 02 Feb 2022 00:38:54 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=IQ96plJnExVz4IofZgZgy11FIOo1veP7nuoBU4KJMcA=; b=t3BixA1nyhgnonhwfnUWptmnyxqfflihVO5U7kPKe5RY4dqQhxYR/sPVwQewTJpjD6 7Dg+G761gg9AZRsE8YUTtsZP6mhaE5PXqBzB+Q9QIXdTZrguq2rnUqW9y1A+tWKCsZZm HaXPOqXSetGRoQoqW2iWNrPp6yZshO8LDfxk71Ms+bqiHLaWPZkfePFtMPHWh7/v8D9Z CZsNpYT7KxOSnJZxVCDrqIHQ/XtOKlIR8WdAytS5G1rgH8A2SmxIC+I3hoODr9v4++oi TFB1N2iYW23m8uyv+l09zLcggVDcwlVyKK/YOTmotnzrEMCgwndXi+k1LutncXjZNZ5F 0wQA== X-Gm-Message-State: AOAM532xqCnlVQ26eQLqUPsEjJHomjY8lA4hUgqYvaxw51aGFopgOSum 0vegZoKfu9LRqpFtsuZjlsUjZWPAGRsF5MH1FP4TLhQQlZo31gVx9xzWu6bi7TJT6z1OIhKccxu IB8Wn5F+Tg4L8CC9JwZMmeXOh X-Received: by 2002:a05:600c:21c1:: with SMTP id x1mr5150573wmj.59.1643791133573; Wed, 02 Feb 2022 00:38:53 -0800 (PST) X-Google-Smtp-Source: ABdhPJxC9orog6Z8LfxDGH06ODz7grjUoMzfg+w2FlDgm3DeIkMP38HoKyw95IAqRi1WUhNTRJi28Q== X-Received: by 2002:a05:600c:21c1:: with SMTP id x1mr5150546wmj.59.1643791133371; Wed, 02 Feb 2022 00:38:53 -0800 (PST) Received: from [192.168.1.102] ([92.176.231.205]) by smtp.gmail.com with ESMTPSA id z17sm3963598wmf.47.2022.02.02.00.38.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Feb 2022 00:38:52 -0800 (PST) Message-ID: Date: Wed, 2 Feb 2022 09:38:51 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Content-Language: en-US To: Sam Ravnborg Cc: Geert Uytterhoeven , Andy Shevchenko , Linux Kernel Mailing List , Linux PWM List , Linux Fbdev development list , Thomas Zimmermann , David Airlie , Daniel Vetter , Mark Brown , DRI Development , Liam Girdwood , =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= , Maxime Ripard , =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , Thierry Reding , Lee Jones , Peter Robinson References: <20220131201225.2324984-1-javierm@redhat.com> <51f54519-bb8b-f108-1c1e-4fed101ca5ef@redhat.com> From: Javier Martinez Canillas In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Sam, On 2/1/22 21:40, Sam Ravnborg wrote: [snip] > > I took a look at the datasheets - and all ssd1305, ssd1306 and ssd1307 > are the same. They have timing constrains on the Vcc. > The random schematic I found on the net showed me that a PWM was used to > control the Vcc voltage - which again is used to control the brightness. > > All the above has nothing to do with backlight - I had this mixed up in > my head. > Yes, same here. I was leaning towards fixing the DT binding but then due Geert comment and after reading the datasheets for ssd130{5,6,7} like you I had the same understanding. Glad that you agree. [snip] > > Last I recommend to drop the fbdev variant - if the drm driver has any > regressions we can fix them. And I do not see any other way to move > users over. Unless their setup breaks then they do not change. > As I mentioned in this thread I wouldn't propose to drop the fbdev variant. I prefer to use the carrot and not the stick. Peter Robinson suggested to make the driver mutually exclusive and add !FB_SSD1307 in the config symbol. I think that makes sense and will do it in v2. Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat