From patchwork Tue Jan 29 08:44:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bartosz Golaszewski X-Patchwork-Id: 1032589 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=bgdev.pl Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=bgdev-pl.20150623.gappssmtp.com header.i=@bgdev-pl.20150623.gappssmtp.com header.b="gUlsvIER"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43pg6S44rXz9sMM for ; Tue, 29 Jan 2019 19:44:48 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727941AbfA2Ioq (ORCPT ); Tue, 29 Jan 2019 03:44:46 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:53277 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728007AbfA2Ioa (ORCPT ); Tue, 29 Jan 2019 03:44:30 -0500 Received: by mail-wm1-f68.google.com with SMTP id d15so16829007wmb.3 for ; Tue, 29 Jan 2019 00:44:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=vHL+0UNr5kGvk4GaQolbiJExCUhkATZNz3ED6gc++tc=; b=gUlsvIERtEqpZBuGE4P4LLxHAjBiyPnHXdPNkJPj1AWHGntJldc5s4zryCYbVpGE5J +ZRykGd0M1asMw0Aq5Bzg+2IC4dUjoXJENa8GQGwdSoZSO/spj0RZsGr+ivEk6vdwWg/ aT3wMc3F0/Q7nLlQqfLejiNdk4L3zFtU53aZHQD+j2LJxywJO9Zu2ZO3oVquHTz4/FmY rTs6uo+RiNk+JfWi6J8OZRmVDFU8Bxo0AMsSJPlKdMevfN75VZvO1s3PGsYmON2sGBsV RC8/NGQJw05k7xpPFC9PHkZhMsrz3v9Fb+4Fmypb8fxz05mwH5H4yHvH2ONQb1ghxyTD msvw== 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=vHL+0UNr5kGvk4GaQolbiJExCUhkATZNz3ED6gc++tc=; b=odfgAx5LPfR7+65N5cWNZbEPGMraLYar7DFCo8/mEpnBO/MdZKjhAocqvw4kXSluOJ t0lw4/4I5GWO2grJsjcL20DUUmwfqDJUJPVF30z8/gZUgIpbeOh7OF8gfur4wgE0VUXC iJWtldY+et2i8vBYB8PgnNVkR19zLkfK41YFfR2cmxDtco0BcgmYRFvcTMtJKhTmU74Z N1v/y8HVW4EvhI6wy2TqsMJ2NzH3rlhBAkvVkvgZNgyoTX833kO1/YKeTDAccZX8naOD LhWMMcndzhn6t5tyWUoo0JaANDFJSpdgAlNSJ07yNUObbM2h73jT7U5CNNRzYPvxUBC5 kt4w== X-Gm-Message-State: AJcUukejJWnjz8ST9omX2tYEQTuum1o20yfVRLl9NpI0mpke55atgay4 sKNqTsmtqb9qwq4JIaowIieUF0UCX/Q= X-Google-Smtp-Source: ALg8bN6zHnlcq0NFmoWfWe5C5gjoqr2/cjzh0TDAJ5PDbL1dXKWPdynk26TIDP+a7aRNrZm2TB9S3Q== X-Received: by 2002:a1c:bbd6:: with SMTP id l205mr19060518wmf.97.1548751468765; Tue, 29 Jan 2019 00:44:28 -0800 (PST) Received: from debian-brgl.home ([2a01:cb1d:af:5b00:6d6c:8493:1ab5:dad7]) by smtp.gmail.com with ESMTPSA id c1sm3979319wmb.14.2019.01.29.00.44.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Jan 2019 00:44:28 -0800 (PST) From: Bartosz Golaszewski To: Linus Walleij , Thomas Gleixner , Marc Zyngier , =?utf-8?q?Uwe_Kleine-K?= =?utf-8?b?w7ZuaWc=?= Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH v2 9/9] gpio: mockup: rework debugfs interface Date: Tue, 29 Jan 2019 09:44:11 +0100 Message-Id: <20190129084411.30495-10-brgl@bgdev.pl> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190129084411.30495-1-brgl@bgdev.pl> References: <20190129084411.30495-1-brgl@bgdev.pl> MIME-Version: 1.0 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org From: Bartosz Golaszewski Modify the way the debugfs interface works in gpio-mockup. Introduce the concept of dummy pull config which will keep the mockup lines in known state. The pull values can be modified by writing to the debugfs files corresponding to lines. Lines in input mode always report the current pull value, lines in output mode change the line value but it will revert back to the one specified by current pull when released. Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mockup.c | 113 ++++++++++++++++++++++++++++++++----- 1 file changed, 99 insertions(+), 14 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index c498b0fbbec8..0b8de6e127eb 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -47,6 +47,7 @@ enum { struct gpio_mockup_line_status { int dir; int value; + int pull; }; struct gpio_mockup_chip { @@ -188,15 +189,56 @@ static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset) return irq_sim_irqnum(&chip->irqsim, offset); } -static ssize_t gpio_mockup_event_write(struct file *file, - const char __user *usr_buf, - size_t size, loff_t *ppos) +static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + + __gpio_mockup_set(chip, offset, chip->lines[offset].pull); +} + +static ssize_t gpio_mockup_debugfs_read(struct file *file, + char __user *usr_buf, + size_t size, loff_t *ppos) +{ + struct gpio_mockup_dbgfs_private *priv; + struct gpio_mockup_chip *chip; + struct seq_file *sfile; + struct gpio_chip *gc; + char buf[3]; + int val, rv; + + if (*ppos != 0) + return 0; + + sfile = file->private_data; + priv = sfile->private; + chip = priv->chip; + gc = &chip->gc; + + val = gpio_mockup_get(gc, priv->offset); + snprintf(buf, sizeof(buf), "%d\n", val); + + rv = copy_to_user(usr_buf, buf, sizeof(buf)); + if (rv) + return rv; + + return sizeof(buf) - 1; +} + +static ssize_t gpio_mockup_debugfs_write(struct file *file, + const char __user *usr_buf, + size_t size, loff_t *ppos) { struct gpio_mockup_dbgfs_private *priv; struct gpio_mockup_chip *chip; struct seq_file *sfile; struct gpio_desc *desc; - int rv, val; + unsigned int irq_type; + struct gpio_chip *gc; + int rv, val, curr; + + if (*ppos != 0) + return -EINVAL; rv = kstrtoint_from_user(usr_buf, size, 0, &val); if (rv) @@ -206,24 +248,66 @@ static ssize_t gpio_mockup_event_write(struct file *file, sfile = file->private_data; priv = sfile->private; - desc = priv->desc; chip = priv->chip; + gc = &chip->gc; + desc = &gc->gpiodev->descs[priv->offset]; + + mutex_lock(&chip->lock); - gpiod_set_value_cansleep(desc, val); - irq_sim_fire(&chip->irqsim, priv->offset); + if (test_bit(FLAG_REQUESTED, &desc->flags) && + !test_bit(FLAG_IS_OUT, &desc->flags)) { + curr = __gpio_mockup_get(chip, priv->offset); + if (curr == val) + goto out; + + irq_type = val == 0 ? IRQ_TYPE_EDGE_FALLING + : IRQ_TYPE_EDGE_RISING; + irq_sim_fire_type(&chip->irqsim, priv->offset, irq_type); + } + + /* Change the value unless we're actively driving the line. */ + if (!test_bit(FLAG_REQUESTED, &desc->flags) || + !test_bit(FLAG_IS_OUT, &desc->flags)) + __gpio_mockup_set(chip, priv->offset, val); + +out: + chip->lines[priv->offset].pull = val; + mutex_unlock(&chip->lock); return size; } -static int gpio_mockup_event_open(struct inode *inode, struct file *file) +static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file) { return single_open(file, NULL, inode->i_private); } -static const struct file_operations gpio_mockup_event_ops = { +/* + * Each mockup chip is represented by a directory named after the chip's device + * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by + * a file using the line's offset as the name under the chip's directory. + * + * Reading from the line's file yields the current *value*, writing to the + * line's file changes the current *pull*. Default pull for mockup lines is + * down. + * + * Examples: + * - when a line pulled down is requested in output mode and driven high, its + * value will return to 0 once it's released + * - when the line is requested in output mode and driven high, writing 0 to + * the corresponding debugfs file will change the pull to down but the + * reported value will still be 1 until the line is released + * - line requested in input mode always reports the same value as its pull + * configuration + * - when the line is requested in input mode and monitored for events, writing + * the same value to the debugfs file will be a noop, while writing the + * opposite value will generate a dummy interrupt with an appropriate edge + */ +static const struct file_operations gpio_mockup_debugfs_ops = { .owner = THIS_MODULE, - .open = gpio_mockup_event_open, - .write = gpio_mockup_event_write, + .open = gpio_mockup_debugfs_open, + .read = gpio_mockup_debugfs_read, + .write = gpio_mockup_debugfs_write, .llseek = no_llseek, }; @@ -258,7 +342,7 @@ static void gpio_mockup_debugfs_setup(struct device *dev, priv->desc = &gc->gpiodev->descs[i]; evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv, - &gpio_mockup_event_ops); + &gpio_mockup_debugfs_ops); if (IS_ERR_OR_NULL(evfile)) goto err; } @@ -266,7 +350,7 @@ static void gpio_mockup_debugfs_setup(struct device *dev, return; err: - dev_err(dev, "error creating debugfs event files\n"); + dev_err(dev, "error creating debugfs files\n"); } static int gpio_mockup_name_lines(struct device *dev, @@ -342,6 +426,7 @@ static int gpio_mockup_probe(struct platform_device *pdev) gc->direction_input = gpio_mockup_dirin; gc->get_direction = gpio_mockup_get_direction; gc->to_irq = gpio_mockup_to_irq; + gc->free = gpio_mockup_free; chip->lines = devm_kcalloc(dev, gc->ngpio, sizeof(*chip->lines), GFP_KERNEL); @@ -415,7 +500,7 @@ static int __init gpio_mockup_init(void) return -EINVAL; } - gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL); + gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL); if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir)) gpio_mockup_err("error creating debugfs directory\n");