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=-13.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 305CFC4360C for ; Tue, 8 Oct 2019 23:21:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEC6D21835 for ; Tue, 8 Oct 2019 23:21:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="shBr879Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726080AbfJHXV2 (ORCPT ); Tue, 8 Oct 2019 19:21:28 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:38712 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfJHXV2 (ORCPT ); Tue, 8 Oct 2019 19:21:28 -0400 Received: by mail-pg1-f194.google.com with SMTP id x10so155953pgi.5 for ; Tue, 08 Oct 2019 16:21:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=S5mtTwOCcjIU4tSsbakveg1/XCMBSFpIuuxRiZvBINE=; b=shBr879ZMVZ6XLpiSZcZIC+5tUgpjtmGTcNgZ6QLqqxImzEOWU4uBSqbP+e84Ikjim rSoD+Q4QiMEuT3ulSANghfh78SHMsIuq6dzOp9HwN7DcSe8XOlTpx6zDarUEPBymg9eN UMdMhrWoVoN/+rKV0S4PrxHnzF+jDGdmToHf2Hy1OE8Qw/U7vWQsdbH3gILaqOAdOT31 9WmjkZlYPba+TBDjotC45aH2GeXN++D3D184w2PkmPdF883v3AQz3b6LJeiqs+KJd/FI Rc9cfKx6g2btjCjJ1R92PpgWBSWkc9cserB953/4aaHsDwWyI0vpHgX9DHGmefAx6Jic rP4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=S5mtTwOCcjIU4tSsbakveg1/XCMBSFpIuuxRiZvBINE=; b=Lpnc68cH8v2jqBGza2/8SCiBt74SshHjXzMld0i2GQp1nqRCZHz/BF1mKwAm9aP15r 57RWslFKFgk+p1FHH5EneFwJ79XfbPC8fstG6GyAFXcQPqzI0AgOaBApjm3oReFjjHB9 wMufmG/Eyw8ec9g302sPiRhpS2UBAOLIogbcjuk3OYqv1AAut/wpNOOo6yCmPYzZWQ68 bRJ5YufUwemMW3O1Tp3DoBDDNKgxfPBrRuFNK8+FxwFF3K2IBbM0+k79haoq6mdZw14F ne0Qtz1MbTk8pP7SIC6+9mcp3LMjDPwBnoQaM5RlEB8CxsRWvR3y0BSyJapXLACg8LEA rFhQ== X-Gm-Message-State: APjAAAVKL35aeHibXxy05TLbb5lEWUaQcb2+Dqppi7pILdhXfrE+qAky Z0Iqu4ozNn/Ux+maFvJHreQ= X-Google-Smtp-Source: APXvYqy7qHmWh3IzeaQgOF6u8YJ5uzBVLEjEsiajWbsA/Rq9kuz7b0bAhxBMcqForHFedjOPYj1psg== X-Received: by 2002:a63:df42:: with SMTP id h2mr895461pgj.405.1570576886909; Tue, 08 Oct 2019 16:21:26 -0700 (PDT) Received: from sol (220-235-84-126.dyn.iinet.net.au. [220.235.84.126]) by smtp.gmail.com with ESMTPSA id f3sm240691pgj.62.2019.10.08.16.21.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 08 Oct 2019 16:21:26 -0700 (PDT) Date: Wed, 9 Oct 2019 07:21:20 +0800 From: Kent Gibson To: Bartosz Golaszewski Cc: Drew Fustini , "open list:GPIO SUBSYSTEM" , Linus Walleij , Thomas Petazzoni Subject: Re: [RFC] gpio: expose pull-up/pull-down line flags to userspace Message-ID: <20191008232120.GA9225@sol> References: <20190921102522.8970-1-drew@pdp7.com> <20191008061512.GA19956@sol> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Tue, Oct 08, 2019 at 10:56:18PM +0200, Bartosz Golaszewski wrote: > wt., 8 paź 2019 o 08:15 Kent Gibson napisał(a): > > > > On Sat, Sep 21, 2019 at 12:25:23PM +0200, Drew Fustini wrote: > > > Add pull-up/pull-down flags to the gpio line get and > > > set ioctl() calls. Use cases include a push button > > > that does not have an external resistor. > > > > > > Addition use cases described by Limor Fried (ladyada) of > > > Adafruit in this PR for Adafruit_Blinka Python lib: > > > https://github.com/adafruit/Adafruit_Blinka/pull/59 > > > > > > Signed-off-by: Drew Fustini > > > --- > > > drivers/gpio/gpiolib.c | 12 ++++++++++++ > > > include/uapi/linux/gpio.h | 4 ++++ > > > 2 files changed, 16 insertions(+) > > > > > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > > > index d9074191edef..9da1093cc7f5 100644 > > > --- a/drivers/gpio/gpiolib.c > > > +++ b/drivers/gpio/gpiolib.c > > > @@ -427,6 +427,8 @@ struct linehandle_state { > > > (GPIOHANDLE_REQUEST_INPUT | \ > > > GPIOHANDLE_REQUEST_OUTPUT | \ > > > GPIOHANDLE_REQUEST_ACTIVE_LOW | \ > > > + GPIOHANDLE_REQUEST_PULL_UP | \ > > > + GPIOHANDLE_REQUEST_PULL_DOWN | \ > > > GPIOHANDLE_REQUEST_OPEN_DRAIN | \ > > > GPIOHANDLE_REQUEST_OPEN_SOURCE) > > > > > > @@ -598,6 +600,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) > > > set_bit(FLAG_OPEN_DRAIN, &desc->flags); > > > if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) > > > set_bit(FLAG_OPEN_SOURCE, &desc->flags); > > > + if (lflags & GPIOHANDLE_REQUEST_PULL_DOWN) > > > + set_bit(FLAG_PULL_DOWN, &desc->flags); > > > + if (lflags & GPIOHANDLE_REQUEST_PULL_UP) > > > + set_bit(FLAG_PULL_UP, &desc->flags); > > > > > > ret = gpiod_set_transitory(desc, false); > > > if (ret < 0) > > > @@ -1102,6 +1108,10 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > > > if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) > > > lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE | > > > GPIOLINE_FLAG_IS_OUT); > > > + if (test_bit(FLAG_PULL_DOWN, &desc->flags)) > > > + lineinfo.flags |= GPIOLINE_FLAG_PULL_DOWN; > > > + if (test_bit(FLAG_PULL_UP, &desc->flags)) > > > + lineinfo.flags |= GPIOLINE_FLAG_PULL_UP; > > > > > > if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) > > > return -EFAULT; > > > @@ -2475,6 +2485,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc) > > > clear_bit(FLAG_REQUESTED, &desc->flags); > > > clear_bit(FLAG_OPEN_DRAIN, &desc->flags); > > > clear_bit(FLAG_OPEN_SOURCE, &desc->flags); > > > + clear_bit(FLAG_PULL_UP, &desc->flags); > > > + clear_bit(FLAG_PULL_DOWN, &desc->flags); > > > clear_bit(FLAG_IS_HOGGED, &desc->flags); > > > ret = true; > > > } > > > diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h > > > index 4ebfe0ac6c5b..c2d1f7d908d6 100644 > > > --- a/include/uapi/linux/gpio.h > > > +++ b/include/uapi/linux/gpio.h > > > @@ -33,6 +33,8 @@ struct gpiochip_info { > > > #define GPIOLINE_FLAG_ACTIVE_LOW (1UL << 2) > > > #define GPIOLINE_FLAG_OPEN_DRAIN (1UL << 3) > > > #define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4) > > > +#define GPIOLINE_FLAG_PULL_UP (1UL << 5) > > > +#define GPIOLINE_FLAG_PULL_DOWN (1UL << 6) > > > > > > /** > > > * struct gpioline_info - Information about a certain GPIO line > > > @@ -62,6 +64,8 @@ struct gpioline_info { > > > #define GPIOHANDLE_REQUEST_ACTIVE_LOW (1UL << 2) > > > #define GPIOHANDLE_REQUEST_OPEN_DRAIN (1UL << 3) > > > #define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4) > > > +#define GPIOHANDLE_REQUEST_PULL_UP (1UL << 5) > > > +#define GPIOHANDLE_REQUEST_PULL_DOWN (1UL << 6) > > > > > > /** > > > * struct gpiohandle_request - Information about a GPIO handle request > > > -- > > > 2.20.1 > > > > > Sorry for the late feedback, but I'm still not sure whether this patch > > is on track to be applied or not. I had thought not, at least not yet, > > but just in case... > > > > It still needs some fixes, but Linus seems to be fine with the general idea. > > > You have added the flags to linehandle_create, but not lineevent_create. > > Given that your primary use case is push buttons, isn't the event request > > at least as important as the handle request? Even ignoring your use > > case, I'd add them to lineevent_create just to maintain symmetry. > > > > Also, is it valid to set PULL_UP and PULL_DOWN simulaneously? > > I would think not, but I could be wrong. > > If not then that combination should be rejected with EINVAL. > > > > Yes, some validity checks of the flags must be added. I even did it in > my local branch[1]. > Your changes for linehandle_create look ok, but for lineevent_create you explicitly disabled PULL_UP and PULL_DOWN, and in a block labelled "This is just wrong: we don't look for events on output lines" at that. > Re: direction and configuration changes on requested lines: I think > it's quite useful to add in the form of a new ioctl(): > GPIOHANDLE_SET_CONFIG_IOCTL or something. I started hacking on this > but eventually got more busy this week than I anticipated. I'm still > planning on sending an RFC by the end of the week though. > I have the reverse problem - bored and looking for something to do, so more than willing to help out - if you want it. And while we're talking, does the gpio-mockup support pull up/down being set from the kernel side? Cheers, Kent. > > [1] https://github.com/brgl/linux/commit/82fc38f6ab599ee03f7a8ed078de8abb41e6e611 > > > Cheers, > > Kent.