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 AC583ECAAD3 for ; Wed, 14 Sep 2022 15:20:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229609AbiINPU1 (ORCPT ); Wed, 14 Sep 2022 11:20:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229919AbiINPU0 (ORCPT ); Wed, 14 Sep 2022 11:20:26 -0400 Received: from mail-qv1-f43.google.com (mail-qv1-f43.google.com [209.85.219.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFD5F1A04F; Wed, 14 Sep 2022 08:20:25 -0700 (PDT) Received: by mail-qv1-f43.google.com with SMTP id v15so11979499qvi.11; Wed, 14 Sep 2022 08:20:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=ojugek6KBkaTNGX1te3XluOa+UNNG5FLDq2Ihxg8cpw=; b=ch097PZ+6l49d6yfzeyBk0u7SivnjtTsh8kf2UJ24dLMn/wxJCprZRjp3HV+spJbKO Lb/FqFFkNIIWsgeOXQWCYkRzvH2gvTQFUiSsbMgian4Ub1H8iaBZFBXNUeRc7mBqF2Nc 31cjsJJJ8dPWGN/KkmcfjZRdMPPHY/iYuOqn6E/qjRoq1twQn4Wq4vkOg8NnYgWgFeTw wPqpIMY2eLr30Yz93ZNqUN/l4jjbb9Mqo+GlpxslyWuECM2M5/zInNrhv1dNpwsrWn3x jBzxfrMpXv5gMe7TffMRWRbWfaUOmfsvh0gd5P6FBTSgXehmcmdA2UMRkrMjjBt7MlZ/ w6oA== X-Gm-Message-State: ACgBeo3uTWSVYzwNK6Z1f6VR8pzWRCaeo3lnwvYM77XkgZ54xkukS4aU iIX0olSPjBoS+TCKAfgVIz8WgN4DJUpwtAHo X-Google-Smtp-Source: AA6agR5NHoenS2uR93eb55l2WFqOGfLmQy+E7nmbH1QnR/3X8Zrc5WSMGk0sO4tQhMZ89FjbhfceTA== X-Received: by 2002:a05:6214:4102:b0:4a8:940b:b752 with SMTP id kc2-20020a056214410200b004a8940bb752mr32846165qvb.68.1663168824680; Wed, 14 Sep 2022 08:20:24 -0700 (PDT) Received: from mail-yb1-f182.google.com (mail-yb1-f182.google.com. [209.85.219.182]) by smtp.gmail.com with ESMTPSA id l14-20020ac84cce000000b0034355a352d1sm1663750qtv.92.2022.09.14.08.20.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 14 Sep 2022 08:20:24 -0700 (PDT) Received: by mail-yb1-f182.google.com with SMTP id e81so3881012ybb.13; Wed, 14 Sep 2022 08:20:24 -0700 (PDT) X-Received: by 2002:a25:3851:0:b0:6ad:9cba:9708 with SMTP id f78-20020a253851000000b006ad9cba9708mr29016892yba.36.1663168823884; Wed, 14 Sep 2022 08:20:23 -0700 (PDT) MIME-Version: 1.0 References: <20220914151145.73253-1-brgl@bgdev.pl> In-Reply-To: <20220914151145.73253-1-brgl@bgdev.pl> From: Geert Uytterhoeven Date: Wed, 14 Sep 2022 16:20:12 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] gpiolib: TODO: add an item about GPIO safe-state To: Bartosz Golaszewski Cc: Kent Gibson , Linus Walleij , Andy Shevchenko , Drew Fustini , Marek Vasut , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi Bartosz, On Wed, Sep 14, 2022 at 4:11 PM Bartosz Golaszewski wrote: > This adds a new TODO item for gpiolib and can also be used to start > a discussion about the need for it and implementation details. > > Signed-off-by: Bartosz Golaszewski > --- a/drivers/gpio/TODO > +++ b/drivers/gpio/TODO > +This item is about proposing a solution, most likely in the form of a new device > +property called "safe-state" that would define the safe states of specific lines > +(e.g. output-high) but not block the line from being requested by users who > +could then modify that default state. Once released the GPIO core would then > +put the line back into the "safe-state". #bikeshedding If this state is the "safe" state, would that imply that any other state is "unsafe"? I guess not, as the idea is that a knowledgeable driver can still change it (else a hog would be sufficient). Hence I think "idle-state" would reflect this better. Any other thoughts? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds