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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ABCE2C10DCE for ; Sun, 8 Mar 2020 13:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80987206D7 for ; Sun, 8 Mar 2020 13:07:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=pdp7-com.20150623.gappssmtp.com header.i=@pdp7-com.20150623.gappssmtp.com header.b="EVi39ie7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726260AbgCHNHq (ORCPT ); Sun, 8 Mar 2020 09:07:46 -0400 Received: from mail-lj1-f175.google.com ([209.85.208.175]:38632 "EHLO mail-lj1-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726259AbgCHNHq (ORCPT ); Sun, 8 Mar 2020 09:07:46 -0400 Received: by mail-lj1-f175.google.com with SMTP id w1so7108739ljh.5 for ; Sun, 08 Mar 2020 06:07:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pdp7-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to:cc; bh=PEjsBmq0oGYsC56UdyYVhp5hPk082kOp1hwXhzk5+QA=; b=EVi39ie7yCBDdR6wSXweQKCjO1koGgSqxEmAhh5N5nhn3KhB0ZDCc8Q3jc43QrQRvT liRJl8tzGgYz/ElHkkLxLAP/kYX0sa2ApUMXDzevGKEf2Gh73yLKvMvSp//ML46svFBY 06HaFYJf/F7nAFvVME1BUf0+NaU+vEMqLL+BhAqDxnqpXQCPCcTYwzFePExs5sbu4FKf MesJ8gnMEVkjtK1svVef/rlpGeMkCu0fESYLXdwOkDI2Xig9yZKsxA5dnqPiVMn7QfBZ nRwAioo6qs4eDGNI387CK/BKQNIYU/pVqL+Jp9GGAUVk439IXy1GxsQcP+hOsIdvZohv TLOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=PEjsBmq0oGYsC56UdyYVhp5hPk082kOp1hwXhzk5+QA=; b=L6wG+eMzYGhBEeudMJVXqSBCE6ZKSDboz+D0s7pvaoEDwxyfYz+9o2qkVkCKY+Rcqc nNnnZGwgaBGNc28yQAY1s5GTUlEBZXAqmiTM7VP1Ky9WCueZNlOrtiiSuD+lsXWI1BfK c6o0YX0esYWs+UNIT80em+8jzlLyK0V0r51vaU5myMN3gfKrCZsHZqvzbbEHZw1T7Nsm +dHQIQt0jJGr4W5J5izU9L8TnYy0UsNClbJ/RO+WA4+LwRKf0MCqWtOC8ch/lBqFVPCp 0IrrVq7McrI3vX977WkVyHasghLWnt+pNhTgM/ubGlA+wzLZ4X0HUUFLTj6Ry89mbDk+ oRUg== X-Gm-Message-State: ANhLgQ18kQ+kElVe1VZa5DZT3ay5rAb63FdiszU6Bd0pTwQfP70tG8bo viuCldrEzfHt0XoCWGzSQaUhBUqGj/hiHnJUpLw= X-Google-Smtp-Source: ADFU+vsu4ysosNA+Yd/FrmgD/b2AhwQsgb7wuGNQRgVMHI7RPEoLbk+YsDutCp+zDlyxBDqNagB3gyJnWESfwd1XqiM= X-Received: by 2002:a2e:9097:: with SMTP id l23mr7552620ljg.155.1583672864653; Sun, 08 Mar 2020 06:07:44 -0700 (PDT) MIME-Version: 1.0 From: Drew Fustini Date: Sun, 8 Mar 2020 14:08:04 +0100 Message-ID: Subject: gpio-omap: add support gpiolib bias (pull-up/down) flags? To: Grygorii Strashko , Santosh Shilimkar , Kevin Hilman Cc: Linus Walleij , "linux-gpio@vger.kernel.org" , Bartosz Golaszewski , Drew Fustini , Kent Gibson , Jason Kridner , Robert Nelson Content-Type: text/plain; charset="UTF-8" Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hello Grygorii, Santosh and Kevin, You are listed as gpio-omap maintainers so I wanted to reach out and get your feedback on this. The gpiolib userspace API added support for bias flags (pull-up/pull-down) in Linux 5.5: [GIT PULL] GPIO changes for v5.5 [1] The merged code is from the patch series: [PATCH v6 0/7] gpio: expose line bias flags to userspace [2] The gpiochip character device now supports theses flags [3]: GPIOHANDLE_REQUEST_BIAS_PULL_UP GPIOHANDLE_REQUEST_BIAS_PULL_DOWN GPIOHANDLE_REQUEST_BIAS_DISABLE The pinctrl-bcm2835 driver used on Raspberry Pi already supports the pull-up/down bias flags [4]. pinctrl-bcm2835 is also a gpio driver [5]. libgpiod v1.5 supports these bias flags [6], so the command line gpioset utility can set the bias flags for a line on the Raspberry Pi [7]. I would like the BeagleBone, which has the TI AM3358 SoC, to be able to use the bias flags as well. The AM3358 uses the gpio-omap GPIO driver. However, gpio-omap does not support these flags [8]. Do you have any feedback on whether this is possible to implement? If so, do you have any guidance about the correct way for me to add support for those bias flags in gpio-omap.c? Thank you, Drew [1] https://www.spinics.net/lists/linux-gpio/msg43719.html [2] https://lore.kernel.org/linux-gpio/CACRpkdbJxcfj6pK=1qjXxffFn0RUH9VD0HRFXX0RoZJDi=hfRw@mail.gmail.com/ [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpiolib.c#n1061 [4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pinctrl/bcm/pinctrl-bcm2835.c#n958 [5] https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/brcm,bcm2835-gpio.txt [6] https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/commit/?h=v1.5.x&id=26d8d8f0b7bc0e300aaab05c75d5af1b0686af08 [7] https://microhobby.com.br/blog/2020/02/02/new-linux-kernel-5-5-new-interfaces-in-gpiolib/ [8] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpio-omap.c