From patchwork Mon Jan 5 18:16:19 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Soren Brinkmann X-Patchwork-Id: 425401 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 660451400D5 for ; Tue, 6 Jan 2015 05:16:48 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753439AbbAESQb (ORCPT ); Mon, 5 Jan 2015 13:16:31 -0500 Received: from mail-ob0-f179.google.com ([209.85.214.179]:51384 "EHLO mail-ob0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753348AbbAESQa (ORCPT ); Mon, 5 Jan 2015 13:16:30 -0500 Received: by mail-ob0-f179.google.com with SMTP id va2so62149550obc.10; Mon, 05 Jan 2015 10:16:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id; bh=siFm1k1gnhsHsL1mXjdesWjtwuRS+KTvD6Ud4JhS8FY=; b=RBpk+XkbsDJn6uK5TGFZ6BC72nHxSBdtg4OyHOfE79/iFLBthrnAAlC/sHGDKLwdi0 W3iPYr9ALOaYFM+cy/uaHekrksVyBfsvj8mZ+asFr0AEuefQZw6pOsWQaYEl1hNvDoMs iQRmfdOdRsIBOSjB5vq8zAks/y1S0OiJRhAWvacPZAOOPzm9U+DBw52hfXjRoVnTTdSt 01n4v//9UeOu2fxOiBAQKKjpemiA5EJU+OqJPK8Wq5bI00YGLhECN4+A1PBebgELDUhw MILfl8B+Lw/CuSmW+q/nRstxg9RM5Wm7vBHaX4ftlrK7vAD0wL+0rwTkvBkJ+kbChKq/ IHZg== X-Received: by 10.60.132.74 with SMTP id os10mr54628086oeb.63.1420481789791; Mon, 05 Jan 2015 10:16:29 -0800 (PST) Received: from localhost ([149.199.62.254]) by mx.google.com with ESMTPSA id v73sm29862414oie.19.2015.01.05.10.16.27 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Jan 2015 10:16:28 -0800 (PST) From: Soren Brinkmann To: Linus Walleij Cc: Alexandre Courbot , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org, Soren Brinkmann Subject: [PATCH RESEND v3] gpio: lib-sysfs: Add 'wakeup' attribute Date: Mon, 5 Jan 2015 10:16:19 -0800 Message-Id: <1420481779-22841-1-git-send-email-soren.brinkmann@xilinx.com> X-Mailer: git-send-email 2.2.1.1.gb42cc81 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Add an attribute 'wakeup' to the GPIO sysfs interface which allows marking/unmarking a GPIO as wake IRQ. The file 'wakeup' is created in each exported GPIOs directory, if an IRQ is associated with that GPIO and the irqchip implements set_wake(). Writing 'enabled' to that file will enable wake for that GPIO, while writing 'disabled' will disable wake. Reading that file will return either 'disabled' or 'enabled' depening on the currently set flag for the GPIO's IRQ. Signed-off-by: Soren Brinkmann Reviewed-by: Alexandre Courbot --- v3: - add documentation v2: - fix error path to unlock mutex before return --- Documentation/ABI/testing/sysfs-gpio | 1 + Documentation/gpio/sysfs.txt | 8 ++++ drivers/gpio/gpiolib-sysfs.c | 77 +++++++++++++++++++++++++++++++++--- 3 files changed, 80 insertions(+), 6 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-gpio b/Documentation/ABI/testing/sysfs-gpio index 80f4c94c7bef..4cc7f4b3f724 100644 --- a/Documentation/ABI/testing/sysfs-gpio +++ b/Documentation/ABI/testing/sysfs-gpio @@ -20,6 +20,7 @@ Description: /value ... always readable, writes fail for input GPIOs /direction ... r/w as: in, out (default low); write: high, low /edge ... r/w as: none, falling, rising, both + /wakeup ... r/w as: enabled, disabled /gpiochipN ... for each gpiochip; #N is its first GPIO /base ... (r/o) same as N /label ... (r/o) descriptive, not necessarily unique diff --git a/Documentation/gpio/sysfs.txt b/Documentation/gpio/sysfs.txt index c2c3a97f8ff7..f703377d528f 100644 --- a/Documentation/gpio/sysfs.txt +++ b/Documentation/gpio/sysfs.txt @@ -97,6 +97,14 @@ and have the following read/write attributes: for "rising" and "falling" edges will follow this setting. + "wakeup" ... reads as either "enabled" or "disabled". Write these + strings to set/clear the 'wakeup' flag of the IRQ associated + with this GPIO. If the IRQ has the 'wakeup' flag set, it can + wake the system from sleep states. + + This file exists only if the pin can generate interrupts and + the driver implements the required infrastructure. + GPIO controllers have paths like /sys/class/gpio/gpiochip42/ (for the controller implementing GPIOs starting at #42) and have the following read-only attributes: diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 2ac1800b58bb..05a5fc9503bd 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -286,6 +286,58 @@ found: static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store); +static ssize_t gpio_wakeup_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + ssize_t status; + const struct gpio_desc *desc = dev_get_drvdata(dev); + int irq = gpiod_to_irq(desc); + struct irq_desc *irq_desc = irq_to_desc(irq); + + mutex_lock(&sysfs_lock); + + if (irqd_is_wakeup_set(&irq_desc->irq_data)) + status = sprintf(buf, "enabled\n"); + else + status = sprintf(buf, "disabled\n"); + + mutex_unlock(&sysfs_lock); + + return status; +} + +static ssize_t gpio_wakeup_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + int ret; + unsigned int on; + struct gpio_desc *desc = dev_get_drvdata(dev); + int irq = gpiod_to_irq(desc); + + mutex_lock(&sysfs_lock); + + if (sysfs_streq("enabled", buf)) { + on = true; + } else if (sysfs_streq("disabled", buf)) { + on = false; + } else { + mutex_unlock(&sysfs_lock); + return -EINVAL; + } + + ret = irq_set_irq_wake(irq, on); + + mutex_unlock(&sysfs_lock); + + if (ret) + pr_warn("%s: failed to %s wake\n", __func__, + on ? "enable" : "disable"); + + return size; +} + +static DEVICE_ATTR(wakeup, 0644, gpio_wakeup_show, gpio_wakeup_store); + static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev, int value) { @@ -526,7 +578,7 @@ static struct class gpio_class = { int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { unsigned long flags; - int status; + int status, irq; const char *ioname = NULL; struct device *dev; int offset; @@ -582,11 +634,24 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) goto fail_unregister_device; } - if (gpiod_to_irq(desc) >= 0 && (direction_may_change || - !test_bit(FLAG_IS_OUT, &desc->flags))) { - status = device_create_file(dev, &dev_attr_edge); - if (status) - goto fail_unregister_device; + irq = gpiod_to_irq(desc); + if (irq >= 0) { + struct irq_desc *irq_desc = irq_to_desc(irq); + struct irq_chip *irqchip = irq_desc_get_chip(irq_desc); + + if (direction_may_change || + !test_bit(FLAG_IS_OUT, &desc->flags)) { + status = device_create_file(dev, &dev_attr_edge); + if (status) + goto fail_unregister_device; + } + + if (irqchip->flags & IRQCHIP_SKIP_SET_WAKE || + irqchip->irq_set_wake) { + status = device_create_file(dev, &dev_attr_wakeup); + if (status) + goto fail_unregister_device; + } } set_bit(FLAG_EXPORT, &desc->flags);