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 6AEE5C433F5 for ; Fri, 25 Mar 2022 16:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230134AbiCYQDi (ORCPT ); Fri, 25 Mar 2022 12:03:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376674AbiCYQDb (ORCPT ); Fri, 25 Mar 2022 12:03:31 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1442A9F38E for ; Fri, 25 Mar 2022 09:01:54 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id y6so5951433plg.2 for ; Fri, 25 Mar 2022 09:01:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=WVe7vUBHguusdempKlMD4/7egQrK1x0/9v7ZHHVmrak=; b=Lf/po27eItEtnnueu+rsj5iZzfhG3emVH+f78rfLLYt/aZ0ISYC/q75edjlGdaotpe yI1BW03PPh8Bflz5d0OMvcvGqjJtNc9QpMD6O2zeZjrXy8MQTE5zFphpnANZdTJRfZi8 PyghdJN4vtxXh1xW6nmbSfjru59R1bqV5Optde56YI+DDqxjNBtp3y/gT4e5EK2QHYJG BJf6pXQDJ8/P9092bwVMRSYEki72vR1bb40AX6s/gGs9RGQx7ykMJtbgbRsAG2qiXWBG dO6Q8fTjt4PYr3lW+oVeRZQNup+Vr9RkaAj4hbYNInMtLz70fMdr138c2yJ4CqosNxoL /OKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=WVe7vUBHguusdempKlMD4/7egQrK1x0/9v7ZHHVmrak=; b=GHmAW2cif0aQVZKCoyKkOPKwa35Fldbcsl2acEUwrg3dWXG9Zbt0pxKURF/7KeGDTn fmAvEZXKOK0S6j98NJUCvYsyT+ABmobVXHETqoqzuZZyMbaVO0ldrSbc3hW2QEc87DFP 7paMXRFOTsShZQlHVIOhqMycp7ER/3C4hx7BkekRQ3EpY4RNL2yuvpXLuE7OGKkTi/q9 DicLfRpsup5HhlvbkXEGx1okdqdpAdG4+qxKm7aWaybe9s0xV2cG6HIScArqmT2SVEXk j7crtrcl0u4wmFG+tJZLUQOa7FUCsRqYHHnhUC3ECZIzmDUXnpXBuN/WQBzbx5nyYm9O cLkg== X-Gm-Message-State: AOAM53268xMMDJS67UKHkWdt4/T4M1GWulOlJ8M4M+/jdN3K2c64r0t6 +9blC3ODIy9de44Ot3n2Zo5MCmi7fKT9sQ== X-Google-Smtp-Source: ABdhPJwflI9/HmrzxxgrsDPYrImSTUXg+s/nKcO6pbpQ4IUxCuAaFxsGfrGQFm7JOmeXF8URVmoxqw== X-Received: by 2002:a17:90a:ba10:b0:1bf:6900:2c5d with SMTP id s16-20020a17090aba1000b001bf69002c5dmr25904940pjr.36.1648224113534; Fri, 25 Mar 2022 09:01:53 -0700 (PDT) Received: from sol ([118.209.204.33]) by smtp.gmail.com with ESMTPSA id s3-20020a056a00194300b004f6da3a1a3bsm7621097pfk.8.2022.03.25.09.01.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Mar 2022 09:01:51 -0700 (PDT) Date: Sat, 26 Mar 2022 00:01:46 +0800 From: Kent Gibson To: =?utf-8?B?SmnFmcOt?= Prchal Cc: linux-gpio@vger.kernel.org, brgl@bgdev.pl, andy.shevchenko@gmail.com Subject: Re: [libgpiod] bug: pull-up does not work Message-ID: <20220325160146.GA49114@sol> References: <62b30818-92fa-e44c-c9dd-fd8cc49a6e6a@aksignal.cz> <20220325145742.GA46960@sol> <48129be0-f29d-96ae-cec3-2b4a2ee10aa8@aksignal.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <48129be0-f29d-96ae-cec3-2b4a2ee10aa8@aksignal.cz> Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Fri, Mar 25, 2022 at 04:13:11PM +0100, Jiří Prchal wrote: > > > On 25. 03. 22 15:57, Kent Gibson wrote: > > On Fri, Mar 25, 2022 at 11:02:07AM +0100, Jiří Prchal wrote: > > > Hi, > > > since in debian is 1.6.2 and pull-up doesn't work so I cloned git, branch > > > next/libgpiod-2.0 and compiled libgpiod and tools, but no luck, same result. > > > > > > > You mean it doesn't work for you on your platform. > > > > The libgpiod-2.0 branch is a work in progress and should not be considered > > the place to go to find solutions to problems with v1.6. > > Not that I'm saying that the v2 branch doesn't work, I'm actually pretty > > sure it does, but its purpose is to switch to the latest kernel uAPI, not > > to provide fixes, should they be needed, for v1.6. > Just thought api v1 doesn't support pull-ups so tried v2. v1 does support bias since Linux v5.5, and libgpiod added support in v1.5. > > > > > ~# uname -r > > > 5.17.0-rc7_cpm9g25 > > > > > > floating pins should go with pull-up/down > > > ~# gpioget -B pull-up 3 6 8 10 12 14 16 18 20 > > > 0 0 0 0 0 0 0 0 > > > ~# gpioget -B pull-up 3 6 8 10 12 14 16 18 20 > > > 1 1 0 0 0 0 0 0 > > > ~# gpioget -B pull-up 3 6 8 10 12 14 16 18 20 > > > 0 1 0 1 0 0 0 0 > > > > > > ~# gpioget -v > > > gpioget (libgpiod) v2.0-devel > > > > > > Whats wrong with it? > > > > You forgot to mention which of those pins are floating. > All of them. > > Or what gpiochip3 is and whether it supports biasing. > AT91SAM9G25, hw supports pull-ups. > > > > So does your chip support pull-up/down? > > The kernel can only enable it if the hardware and pinctrl driver supports it. > Is there possibility that pinctrl doesn't support it? I think other gpios > used in kernel are with pull-up. > Example: > pinctrl@fffff400 { > 1wire { > pinctrl_1wire: 1wire-0 { > atmel,pins = ; /* PC0 > PIO, pull-up */ > }; > }; > }; > Pinctrl and device tree are outside my area, but my understanding is that setting via DT is a separate interface, so while it may be supported by DT it may not be via the gpiolib interface. But I will defer to anyone else on that. (CCing in Andy since I'm pretty sure he would know) Not sure which pinctrl is relevant for your case. pinctrl-at91 doesn't appear to support setting the pull-up via the gpiolib interface, but pinctrl-at91-pio4 does, so my guess would be you are using the pinctrl-at91. But again, this is outside my area so you would need to confirm that yourself or get feedback from someone else. If you determine that you are using a pinctrl that supports setting bias via gpiolib then we'll have to do some more digging. Cheers, Kent.