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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 5F98AC47420 for ; Wed, 23 Sep 2020 16:15:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 215702068E for ; Wed, 23 Sep 2020 16:15:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ExW7pkxk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726806AbgIWQPK (ORCPT ); Wed, 23 Sep 2020 12:15:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726751AbgIWQPF (ORCPT ); Wed, 23 Sep 2020 12:15:05 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00AD7C0613CE; Wed, 23 Sep 2020 09:15:05 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id r19so7125954pls.1; Wed, 23 Sep 2020 09:15:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=x6iIQgJBK/hJQqgHIKT64599BO9JBAn8oS/j+kepF7o=; b=ExW7pkxkigfGvSnfeirvSmaDfI6eXFwyGfzA/me/HOmXjy2/2H8HGLhU0FCqhgxOR8 Eec35pOvVzLcAz6fuuuIUKFZabtKpMFetjYYMTy1lLnV+4tO6T6KBDmNoKcbVZQi8wQ1 fX3f76747FpFgZUahFvQTACtX0oJcUPLJBryghMLdVbEmEjsbhQJLJ22AO2jdSbyd8Cm jd1q4Z3mJNAJUhERw6P3O2DovjVWlAfdJunH+aDJoD9TAqwlXLUDUfqMgh2gFFcdg3yK sjBz2jIwRcUtucN1Wnkt2gD2nC69aO+ragJD8YEWkuIlEc1Mskiy2XIhYaSGZS1/1eyU RP5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=x6iIQgJBK/hJQqgHIKT64599BO9JBAn8oS/j+kepF7o=; b=mfVUxoU7wjBwuPVqkvg9neEFx2ekdO8FJupNWeMfulIDKG5K4Ha03uzujOENKbSSj0 fYdrwZRnniuHMwUxMJiTG44qVJGxNJafAUO6eqWVKrIy1e4/6zsPiwDuQVmljcdbyAj3 z6NRVjHcjyGLoVOzwgcvBf+4imrrPfi/hRnlxDJU0NvZ+HV3FPjPBvHhNPzAkFrfEk9i 0sCFHrqB9/AW0v1LyNh/UOXPBVKFQ/iV3pP0vIO7oFNUPDNs81Ofzmruu+ewbFVyR1jM g2x8DDckA7dCZeB8ogTmxFFndAQoID90mR1xm7BWSiUay8LmdEoDH/llQ4cK234B9SGf zQFQ== X-Gm-Message-State: AOAM530o1BcuhjG9yTfMLQb9KHKUQFz56I61EWojv/w9VlTUb94jPfI5 6YanwYCnPkELX57uHcjGgSJpMMhd5iNvfAdsiTvEamvv0Vg3MA== X-Google-Smtp-Source: ABdhPJwPeQSwLuXRdkYLF2gEQVkYzO1KYJC6Y6qqxX3Yt5NfifWO1YvqqXp4JH23ZiHytQb0PoP9z+uRy55+u2kJsRU= X-Received: by 2002:a17:902:778b:b029:d1:bb21:513d with SMTP id o11-20020a170902778bb02900d1bb21513dmr525954pll.17.1600877704397; Wed, 23 Sep 2020 09:15:04 -0700 (PDT) MIME-Version: 1.0 References: <20200922023151.387447-1-warthog618@gmail.com> <20200922023151.387447-11-warthog618@gmail.com> In-Reply-To: <20200922023151.387447-11-warthog618@gmail.com> From: Andy Shevchenko Date: Wed, 23 Sep 2020 19:14:43 +0300 Message-ID: Subject: Re: [PATCH v9 10/20] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL To: Kent Gibson Cc: Linux Kernel Mailing List , "open list:GPIO SUBSYSTEM" , Bartosz Golaszewski , Linus Walleij , Arnd Bergmann Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Tue, Sep 22, 2020 at 5:35 AM Kent Gibson wrote: > > Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2 > line set config ioctl. > > Signed-off-by: Kent Gibson > --- > drivers/gpio/gpiolib-cdev.c | 88 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 88 insertions(+) > > diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c > index 145bda2151fb..debd3b277523 100644 > --- a/drivers/gpio/gpiolib-cdev.c > +++ b/drivers/gpio/gpiolib-cdev.c > @@ -16,6 +16,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -444,6 +445,8 @@ struct line { > * @seqno: the sequence number for edge events generated on all lines in > * this line request. Note that this is not used when @num_lines is 1, as > * the line_seqno is then the same and is cheaper to calculate. > + * @config_mutex: mutex for serializing ioctl() calls to ensure consistency > + * of configuration, particularly multi-step accesses to desc flags. > * @lines: the lines held by this line request, with @num_lines elements. > */ > struct linereq { > @@ -454,6 +457,7 @@ struct linereq { > u32 event_buffer_size; > DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); > atomic_t seqno; > + struct mutex config_mutex; > struct line lines[]; > }; > > @@ -573,6 +577,8 @@ static void edge_detector_stop(struct line *line) > free_irq(line->irq, line); > line->irq = 0; > } > + > + line->eflags = 0; > } > > static int edge_detector_setup(struct line *line, > @@ -614,6 +620,17 @@ static int edge_detector_setup(struct line *line, > return 0; > } > > +static int edge_detector_update(struct line *line, u64 eflags, > + bool polarity_change) > +{ > + if ((line->eflags == eflags) && !polarity_change) > + return 0; > + > + edge_detector_stop(line); > + > + return edge_detector_setup(line, eflags); > +} > + > static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, > unsigned int line_idx) > { > @@ -796,6 +813,74 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) > return 0; > } > > +static long linereq_set_config_unlocked(struct linereq *lr, > + struct gpio_v2_line_config *lc) > +{ > + struct gpio_desc *desc; > + unsigned int i; > + u64 flags; > + bool polarity_change; > + int ret; > + > + for (i = 0; i < lr->num_lines; i++) { > + desc = lr->lines[i].desc; > + flags = gpio_v2_line_config_flags(lc, i); > + polarity_change = > + (test_bit(FLAG_ACTIVE_LOW, &desc->flags) != > + ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0)); Comparison > + > + gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); > + /* > + * Lines have to be requested explicitly for input > + * or output, else the line will be treated "as is". > + */ > + if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { > + int val = gpio_v2_line_config_output_value(lc, i); > + > + edge_detector_stop(&lr->lines[i]); > + ret = gpiod_direction_output(desc, val); > + if (ret) > + return ret; > + } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { > + ret = gpiod_direction_input(desc); > + if (ret) > + return ret; > + > + ret = edge_detector_update(&lr->lines[i], > + flags & GPIO_V2_LINE_EDGE_FLAGS, > + polarity_change); > + if (ret) > + return ret; > + } > + > + blocking_notifier_call_chain(&desc->gdev->notifier, > + GPIO_V2_LINE_CHANGED_CONFIG, > + desc); > + } > + return 0; > +} > + > +static long linereq_set_config(struct linereq *lr, void __user *ip) > +{ > + struct gpio_v2_line_config lc; > + int ret; > + > + if (copy_from_user(&lc, ip, sizeof(lc))) > + return -EFAULT; > + > + ret = gpio_v2_line_config_validate(&lc, lr->num_lines); > + if (ret) > + return ret; > + > + mutex_lock(&lr->config_mutex); > + > + ret = linereq_set_config_unlocked(lr, &lc); > + > + mutex_unlock(&lr->config_mutex); > + > + return ret; > +} > + > static long linereq_ioctl(struct file *file, unsigned int cmd, > unsigned long arg) > { > @@ -804,6 +889,8 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, > > if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL) > return linereq_get_values(lr, ip); > + else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL) > + return linereq_set_config(lr, ip); > > return -EINVAL; > } > @@ -964,6 +1051,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) > } > } > > + mutex_init(&lr->config_mutex); > init_waitqueue_head(&lr->wait); > lr->event_buffer_size = ulr.event_buffer_size; > if (lr->event_buffer_size == 0) > -- > 2.28.0 > -- With Best Regards, Andy Shevchenko