From patchwork Sat Nov 30 07:54:32 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Shiyan X-Patchwork-Id: 295547 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id CB8C32C009F for ; Sat, 30 Nov 2013 18:55:05 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751017Ab3K3HzE (ORCPT ); Sat, 30 Nov 2013 02:55:04 -0500 Received: from smtp38.i.mail.ru ([94.100.177.98]:58661 "EHLO smtp38.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750835Ab3K3HzD (ORCPT ); Sat, 30 Nov 2013 02:55:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mail.ru; s=mail2; h=Message-Id:Date:Subject:Cc:To:From; bh=AAP+O28UhS6U0KXSjGvrZwFsemuy2tpGIS26AYqoMPg=; b=ulEvMVJCphdWTFqksG4ENwawzedzGhW/RiHe7nlNZBUr9HASpm7s3Qy90TdqxqXA4ELd94uiaRWbMwRZv9Epnli6UQK0JZZ1jipDEGS1nDI6qO26cTG7cm0j4oUwHtfiVZIFPQl1h/ygwaNdiQof+2ROvbUNjwSRKn0n95V0tBU=; Received: from [188.134.40.128] (port=36562 helo=shc.zet) by smtp38.i.mail.ru with esmtpa (envelope-from ) id 1VmfOG-0001K8-Jz; Sat, 30 Nov 2013 11:55:00 +0400 From: Alexander Shiyan To: linux-watchdog@vger.kernel.org Cc: devicetree@vger.kernel.org, Wim Van Sebroeck , Guenter Roeck , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Grant Likely , Alexander Shiyan Subject: [PATCH v3] watchdog: GPIO-controlled watchdog Date: Sat, 30 Nov 2013 11:54:32 +0400 Message-Id: <1385798072-3886-1-git-send-email-shc_work@mail.ru> X-Mailer: git-send-email 1.8.3.2 X-Spam: Not detected X-Mras: Ok Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This patch adds a watchdog driver for devices controlled through GPIO, (Analog Devices ADM706, Maxim MAX823, National NE555 etc). Signed-off-by: Alexander Shiyan --- .../devicetree/bindings/watchdog/gpio-wdt.txt | 23 ++ drivers/watchdog/Kconfig | 8 + drivers/watchdog/Makefile | 1 + drivers/watchdog/gpio_wdt.c | 254 +++++++++++++++++++++ 4 files changed, 286 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/gpio-wdt.txt create mode 100644 drivers/watchdog/gpio_wdt.c diff --git a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt new file mode 100644 index 0000000..37afec1 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt @@ -0,0 +1,23 @@ +* GPIO-controlled Watchdog + +Required Properties: +- compatible: Should contain "linux,wdt-gpio". +- gpios: From common gpio binding; gpio connection to WDT reset pin. +- hw_algo: The algorithm used by the driver. Should be one of the + following values: + - toggle: Either a high-to-low or a low-to-high transition clears + the WDT counter. The watchdog timer is disabled when GPIO is + left floating or connected to a three-state buffer. + - level: Low or high level starts counting WDT timeout, + the opposite level disables the WDT. Active level is determined + by the GPIO flags. +- hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds). + +Example: + watchdog: watchdog { + /* ADM706 */ + compatible = "linux,wdt-gpio"; + gpios = <&gpio3 9 GPIO_ACTIVE_LOW>; + hw_algo = "toggle"; + hw_margin_ms = <1600>; + }; diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 5be6e91..968a882 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -87,6 +87,14 @@ config DA9055_WATCHDOG This driver can also be built as a module. If so, the module will be called da9055_wdt. +config GPIO_WATCHDOG + tristate "Watchdog device controlled through GPIO-line" + depends on OF_GPIO + select WATCHDOG_CORE + help + If you say yes here you get support for watchdog device + controlled through GPIO-line. + config WM831X_WATCHDOG tristate "WM831x watchdog" depends on MFD_WM831X diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 91bd95a..dc17275 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -171,6 +171,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o # Architecture Independent obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o +obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c new file mode 100644 index 0000000..1e02dd6 --- /dev/null +++ b/drivers/watchdog/gpio_wdt.c @@ -0,0 +1,254 @@ +/* + * Driver for watchdog device controlled through GPIO-line + * + * Author: 2013, Alexander Shiyan + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define SOFT_TIMEOUT_MIN 1 +#define SOFT_TIMEOUT_DEF 60 +#define SOFT_TIMEOUT_MAX 0xffff + +enum { + HW_ALGO_TOGGLE, + HW_ALGO_LEVEL, +}; + +struct gpio_wdt_priv { + int gpio; + bool active_low; + bool state; + unsigned int hw_algo; + unsigned int hw_margin; + unsigned long last_jiffies; + struct notifier_block notifier; + struct timer_list timer; + struct watchdog_device wdd; +}; + +static void gpio_wdt_disable(struct gpio_wdt_priv *priv) +{ + gpio_set_value_cansleep(priv->gpio, !priv->active_low); + + /* Put GPIO back to tristate */ + if (priv->hw_algo == HW_ALGO_TOGGLE) + gpio_direction_input(priv->gpio); +} + +static int gpio_wdt_start(struct watchdog_device *wdd) +{ + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); + + priv->state = priv->active_low; + gpio_direction_output(priv->gpio, priv->state); + priv->last_jiffies = jiffies; + mod_timer(&priv->timer, priv->last_jiffies + priv->hw_margin); + + return 0; +} + +static int gpio_wdt_stop(struct watchdog_device *wdd) +{ + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); + + mod_timer(&priv->timer, 0); + gpio_wdt_disable(priv); + + return 0; +} + +static int gpio_wdt_ping(struct watchdog_device *wdd) +{ + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); + + priv->last_jiffies = jiffies; + + return 0; +} + +static int gpio_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) +{ + wdd->timeout = t; + + return gpio_wdt_ping(wdd); +} + +static void gpio_wdt_hwping(unsigned long data) +{ + struct watchdog_device *wdd = (struct watchdog_device *)data; + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd); + + if (time_after(jiffies, priv->last_jiffies + + msecs_to_jiffies(wdd->timeout * 1000))) { + dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n"); + return; + } + + /* Restart timer */ + mod_timer(&priv->timer, jiffies + priv->hw_margin); + + switch (priv->hw_algo) { + case HW_ALGO_TOGGLE: + /* Toggle output pin */ + priv->state = !priv->state; + gpio_set_value_cansleep(priv->gpio, priv->state); + break; + case HW_ALGO_LEVEL: + /* Pulse */ + gpio_set_value_cansleep(priv->gpio, !priv->active_low); + udelay(1); + gpio_set_value_cansleep(priv->gpio, priv->active_low); + break; + } +} + +static int gpio_wdt_notify_sys(struct notifier_block *nb, unsigned long code, + void *unused) +{ + struct gpio_wdt_priv *priv = container_of(nb, struct gpio_wdt_priv, + notifier); + + mod_timer(&priv->timer, 0); + + switch (code) { + case SYS_HALT: + case SYS_POWER_OFF: + gpio_wdt_disable(priv); + break; + default: + break; + } + + return NOTIFY_DONE; +} + +static const struct watchdog_info gpio_wdt_ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT, + .identity = "GPIO Watchdog", +}; + +static const struct watchdog_ops gpio_wdt_ops = { + .owner = THIS_MODULE, + .start = gpio_wdt_start, + .stop = gpio_wdt_stop, + .ping = gpio_wdt_ping, + .set_timeout = gpio_wdt_set_timeout, +}; + +static int gpio_wdt_probe(struct platform_device *pdev) +{ + struct gpio_wdt_priv *priv; + enum of_gpio_flags flags; + unsigned int hw_margin; + unsigned long f = 0; + const char *algo; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->gpio = of_get_gpio_flags(pdev->dev.of_node, 0, &flags); + if (!gpio_is_valid(priv->gpio)) + return priv->gpio; + + priv->active_low = flags & OF_GPIO_ACTIVE_LOW; + + ret = of_property_read_string(pdev->dev.of_node, "hw_algo", &algo); + if (ret) + return ret; + if (!strncmp(algo, "toggle", 6)) { + priv->hw_algo = HW_ALGO_TOGGLE; + f = GPIOF_IN; + } else if (!strncmp(algo, "level", 5)) { + priv->hw_algo = HW_ALGO_LEVEL; + f = priv->active_low ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; + } else { + return -EINVAL; + } + + ret = devm_gpio_request_one(&pdev->dev, priv->gpio, f, + dev_name(&pdev->dev)); + if (ret) + return ret; + + ret = of_property_read_u32(pdev->dev.of_node, + "hw_margin_ms", &hw_margin); + if (ret) + return ret; + /* Disallow values lower than 2 and higher than 65535 ms */ + if ((hw_margin < 2) || (hw_margin > 65535)) + return -EINVAL; + + /* Use safe value (1/2 of real timeout) */ + priv->hw_margin = msecs_to_jiffies(hw_margin / 2); + + watchdog_set_drvdata(&priv->wdd, priv); + + priv->wdd.info = &gpio_wdt_ident; + priv->wdd.ops = &gpio_wdt_ops; + priv->wdd.min_timeout = SOFT_TIMEOUT_MIN; + priv->wdd.max_timeout = SOFT_TIMEOUT_MAX; + + if (watchdog_init_timeout(&priv->wdd, 0, &pdev->dev) < 0) + priv->wdd.timeout = SOFT_TIMEOUT_DEF; + + setup_timer(&priv->timer, gpio_wdt_hwping, (unsigned long)&priv->wdd); + + ret = watchdog_register_device(&priv->wdd); + if (ret) + return ret; + + priv->notifier.notifier_call = gpio_wdt_notify_sys; + ret = register_reboot_notifier(&priv->notifier); + if (ret) + watchdog_unregister_device(&priv->wdd); + + return ret; +} + +static int gpio_wdt_remove(struct platform_device *pdev) +{ + struct gpio_wdt_priv *priv = platform_get_drvdata(pdev); + + del_timer_sync(&priv->timer); + unregister_reboot_notifier(&priv->notifier); + watchdog_unregister_device(&priv->wdd); + + return 0; +} + +static const struct of_device_id gpio_wdt_dt_ids[] = { + { .compatible = "linux,wdt-gpio", }, + { } +}; +MODULE_DEVICE_TABLE(of, gpio_wdt_dt_ids); + +static struct platform_driver gpio_wdt_driver = { + .driver = { + .name = "gpio-wdt", + .owner = THIS_MODULE, + .of_match_table = gpio_wdt_dt_ids, + }, + .probe = gpio_wdt_probe, + .remove = gpio_wdt_remove, +}; +module_platform_driver(gpio_wdt_driver); + +MODULE_AUTHOR("Alexander Shiyan "); +MODULE_DESCRIPTION("GPIO Watchdog"); +MODULE_LICENSE("GPL");