From patchwork Mon Sep 28 00:27:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kent Gibson X-Patchwork-Id: 254324 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=-12.8 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, USER_AGENT_GIT 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 48F3BC4346E for ; Mon, 28 Sep 2020 00:30:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 012F0206B8 for ; Mon, 28 Sep 2020 00:30:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i7Rn2dvb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726440AbgI1Aao (ORCPT ); Sun, 27 Sep 2020 20:30:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726387AbgI1Aao (ORCPT ); Sun, 27 Sep 2020 20:30:44 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31FADC0613CE; Sun, 27 Sep 2020 17:30:44 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id s14so1442901pju.1; Sun, 27 Sep 2020 17:30:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=imYtZiSX5AvWbH/xY/JjjqLmyT8ivLM44f4A3aeUozs=; b=i7Rn2dvb++mzLSNbsHPhMTk0eBbBOGSUr0Q+b6IYgqimkBeGNaRyOppX51BfEGx9CY Ozg69Pj25EBuQe3YNF6DoDYycPcJicoQXaetr7a8X3NAMG4wMIk4j7zRZSALZQE3kylo uE19QjsbzPY2rizHxATxNU5RLDupVOoxiYDglO3NyD+MHr0JLWfxozfZe6p9gRiZoohs iUcnByVPXBZidLvaR74TTxe6W4LuCjx+M+2i15G/5dFOWqs556GEabQ2iPwlZxSgPMQ8 WzHl51h7eHkGst0PfJF4Nk+BFBOw+2UvburU9ZTLAM0SWlcLF3f19jKO22uekHRbzKgQ 7d6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=imYtZiSX5AvWbH/xY/JjjqLmyT8ivLM44f4A3aeUozs=; b=iLwGvSBBtzaufVbzp5O8ry7WbJhGWCZql47TvPZUpJ0Vtg7eKwfJ44KJSD/Z1Ij7Cj e3UKD6l0hUbceAFpW/jkRFMgLV3z50t/Hq6N8ZMkLTjtVhhyyrDnZ69BR7k88VDB18OI MPQx4YzT6jGjCnZlqi1X4TfKgbY57JTapXZZ1kohE2oxNjZuauMOoQKhWS5MTG3XGQPf RqxLYjzx0aq4EYYFX2d99Hx4n7j7NN30aBVBRtJtnHOn7zIgKCe4pRHv5nSj8NI0GubO hCgy7j5IS8rJ1/0jTHHOP3J7at/FTxryShRd+Ltw9joU4yPdRwMK7az27+SmAiJe9Xph EMUw== X-Gm-Message-State: AOAM533n8dC3ZSnLHgWpyz0LyW3ip9EztARV2vV2wJw53rwgJw0fCUq2 3wL3vWU2iyEoChXv1I3XGQZKhOGwVlDyPA== X-Google-Smtp-Source: ABdhPJwGk7XnXmlNvvpF9HREUQ2lVj76/fT/cR33UqDFbII82c4MckDAR3+xffUDGG3OQiq88oSXVQ== X-Received: by 2002:a17:90a:156:: with SMTP id z22mr7188799pje.140.1601253043313; Sun, 27 Sep 2020 17:30:43 -0700 (PDT) Received: from sol.lan (106-69-171-132.dyn.iinet.net.au. [106.69.171.132]) by smtp.gmail.com with ESMTPSA id o20sm8443783pgh.63.2020.09.27.17.30.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Sep 2020 17:30:42 -0700 (PDT) From: Kent Gibson To: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, bgolaszewski@baylibre.com, linus.walleij@linaro.org, andy.shevchenko@gmail.com, arnd@arndb.de Cc: Kent Gibson Subject: [PATCH v10 10/20] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL Date: Mon, 28 Sep 2020 08:27:57 +0800 Message-Id: <20200928002807.12146-11-warthog618@gmail.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200928002807.12146-1-warthog618@gmail.com> References: <20200928002807.12146-1-warthog618@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org 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 868fcf89478c..608cdbd1d579 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[]; }; @@ -574,6 +578,8 @@ 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, @@ -615,6 +621,17 @@ 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) { @@ -799,6 +816,74 @@ 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)); + + 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) { @@ -807,6 +892,8 @@ 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; } @@ -968,6 +1055,7 @@ 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)