This generic GPIO watchdog is used on Huawei E970 (bcm47xx) Signed-off-by: Mathias Adam --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1755,6 +1755,15 @@ config WDT_MTX1 Hardware driver for the MTX-1 boards. This is a watchdog timer that will reboot the machine after a 100 seconds timer expired. +config GPIO_WDT + tristate "GPIO Hardware Watchdog" + help + Hardware driver for GPIO-controlled watchdogs. GPIO pin and + toggle interval settings are platform-specific. The driver + will stop toggling the GPIO (i.e. machine reboots) after a + 100 second timer expired and no process has written to + /dev/watchdog during that time. + config SIBYTE_WDOG tristate "Sibyte SoC hardware watchdog" depends on CPU_SB1 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -167,6 +167,7 @@ obj-$(CONFIG_RC32434_WDT) += rc32434_wdt obj-$(CONFIG_INDYDOG) += indydog.o obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o +obj-$(CONFIG_GPIO_WDT) += old_gpio_wdt.o obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o obj-$(CONFIG_AR7_WDT) += ar7_wdt.o obj-$(CONFIG_TXX9_WDT) += txx9wdt.o --- /dev/null +++ b/drivers/watchdog/old_gpio_wdt.c @@ -0,0 +1,300 @@ +/* + * Driver for GPIO-controlled Hardware Watchdogs. + * + * Copyright (C) 2013 Mathias Adam + * + * Replaces mtx1_wdt (driver for the MTX-1 Watchdog): + * + * (C) Copyright 2005 4G Systems , + * All Rights Reserved. + * http://www.4g-systems.biz + * + * (C) Copyright 2007 OpenWrt.org, Florian Fainelli + * + * 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. + * + * Neither Michael Stickel nor 4G Systems admit liability nor provide + * warranty for any of this software. This material is provided + * "AS-IS" and at no charge. + * + * (c) Copyright 2005 4G Systems + * + * Release 0.01. + * Author: Michael Stickel michael.stickel@4g-systems.biz + * + * Release 0.02. + * Author: Florian Fainelli florian@openwrt.org + * use the Linux watchdog/timer APIs + * + * Release 0.03. + * Author: Mathias Adam + * make it a generic gpio watchdog driver + * + * The Watchdog is configured to reset the MTX-1 + * if it is not triggered for 100 seconds. + * It should not be triggered more often than 1.6 seconds. + * + * A timer triggers the watchdog every 5 seconds, until + * it is opened for the first time. After the first open + * it MUST be triggered every 2..95 seconds. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int ticks = 100 * HZ; + +static struct { + struct completion stop; + spinlock_t lock; + int running; + struct timer_list timer; + int queue; + int default_ticks; + unsigned long inuse; + unsigned gpio; + unsigned int gstate; + int interval; + int first_interval; +} gpio_wdt_device; + +static void gpio_wdt_trigger(struct timer_list *unused) +{ + spin_lock(&gpio_wdt_device.lock); + if (gpio_wdt_device.running && ticks > 0) + ticks -= gpio_wdt_device.interval; + + /* toggle wdt gpio */ + gpio_wdt_device.gstate = !gpio_wdt_device.gstate; + gpio_set_value(gpio_wdt_device.gpio, gpio_wdt_device.gstate); + + if (gpio_wdt_device.queue && ticks > 0) + mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.interval); + else + complete(&gpio_wdt_device.stop); + spin_unlock(&gpio_wdt_device.lock); +} + +static void gpio_wdt_reset(void) +{ + ticks = gpio_wdt_device.default_ticks; +} + + +static void gpio_wdt_start(void) +{ + unsigned long flags; + + spin_lock_irqsave(&gpio_wdt_device.lock, flags); + if (!gpio_wdt_device.queue) { + gpio_wdt_device.queue = 1; + gpio_wdt_device.gstate = 1; + gpio_set_value(gpio_wdt_device.gpio, 1); + mod_timer(&gpio_wdt_device.timer, jiffies + gpio_wdt_device.first_interval); + } + gpio_wdt_device.running++; + spin_unlock_irqrestore(&gpio_wdt_device.lock, flags); +} + +static int gpio_wdt_stop(void) +{ + unsigned long flags; + + spin_lock_irqsave(&gpio_wdt_device.lock, flags); + if (gpio_wdt_device.queue) { + gpio_wdt_device.queue = 0; + gpio_wdt_device.gstate = 0; + gpio_set_value(gpio_wdt_device.gpio, 0); + } + ticks = gpio_wdt_device.default_ticks; + spin_unlock_irqrestore(&gpio_wdt_device.lock, flags); + return 0; +} + +/* Filesystem functions */ + +static int gpio_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &gpio_wdt_device.inuse)) + return -EBUSY; + return nonseekable_open(inode, file); +} + + +static int gpio_wdt_release(struct inode *inode, struct file *file) +{ + clear_bit(0, &gpio_wdt_device.inuse); + return 0; +} + +static long gpio_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = (int __user *)argp; + unsigned int value; + static const struct watchdog_info ident = { + .options = WDIOF_CARDRESET, + .identity = "GPIO WDT", + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + if (copy_to_user(argp, &ident, sizeof(ident))) + return -EFAULT; + break; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + put_user(0, p); + break; + case WDIOC_SETOPTIONS: + if (get_user(value, p)) + return -EFAULT; + if (value & WDIOS_ENABLECARD) + gpio_wdt_start(); + else if (value & WDIOS_DISABLECARD) + gpio_wdt_stop(); + else + return -EINVAL; + return 0; + case WDIOC_KEEPALIVE: + gpio_wdt_reset(); + break; + default: + return -ENOTTY; + } + return 0; +} + + +static ssize_t gpio_wdt_write(struct file *file, const char *buf, + size_t count, loff_t *ppos) +{ + if (!count) + return -EIO; + gpio_wdt_reset(); + return count; +} + +static const struct file_operations gpio_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .unlocked_ioctl = gpio_wdt_ioctl, + .open = gpio_wdt_open, + .write = gpio_wdt_write, + .release = gpio_wdt_release, +}; + + +static struct miscdevice gpio_wdt_misc = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &gpio_wdt_fops, +}; + + +static int gpio_wdt_probe(struct platform_device *pdev) +{ + int ret; + struct gpio_wdt_platform_data *gpio_wdt_data = pdev->dev.platform_data; + + gpio_wdt_device.gpio = gpio_wdt_data->gpio; + gpio_wdt_device.interval = gpio_wdt_data->interval; + gpio_wdt_device.first_interval = gpio_wdt_data->first_interval; + if (gpio_wdt_device.first_interval <= 0) { + gpio_wdt_device.first_interval = gpio_wdt_device.interval; + } + + ret = gpio_request(gpio_wdt_device.gpio, "gpio-wdt"); + if (ret < 0) { + dev_err(&pdev->dev, "failed to request gpio"); + return ret; + } + + spin_lock_init(&gpio_wdt_device.lock); + init_completion(&gpio_wdt_device.stop); + gpio_wdt_device.queue = 0; + clear_bit(0, &gpio_wdt_device.inuse); + timer_setup(&gpio_wdt_device.timer, gpio_wdt_trigger, 0L); + gpio_wdt_device.default_ticks = ticks; + + gpio_wdt_start(); + dev_info(&pdev->dev, "GPIO Hardware Watchdog driver (gpio=%i interval=%i/%i)\n", + gpio_wdt_data->gpio, gpio_wdt_data->first_interval, gpio_wdt_data->interval); + return 0; +} + +static int gpio_wdt_remove(struct platform_device *pdev) +{ + /* FIXME: do we need to lock this test ? */ + if (gpio_wdt_device.queue) { + gpio_wdt_device.queue = 0; + wait_for_completion(&gpio_wdt_device.stop); + } + + gpio_free(gpio_wdt_device.gpio); + misc_deregister(&gpio_wdt_misc); + return 0; +} + +static struct platform_driver gpio_wdt_driver = { + .probe = gpio_wdt_probe, + .remove = gpio_wdt_remove, + .driver.name = "gpio-wdt", +}; + +static int __init gpio_wdt_init(void) +{ + return platform_driver_register(&gpio_wdt_driver); +} +arch_initcall(gpio_wdt_init); + +/* + * We do wdt initialization in two steps: arch_initcall probes the wdt + * very early to start pinging the watchdog (misc devices are not yet + * available), and later module_init() just registers the misc device. + */ +static int gpio_wdt_init_late(void) +{ + int ret; + + ret = misc_register(&gpio_wdt_misc); + if (ret < 0) { + pr_err("GPIO_WDT: failed to register misc device\n"); + return ret; + } + return 0; +} +#ifndef MODULE +module_init(gpio_wdt_init_late); +#endif + +static void __exit gpio_wdt_exit(void) +{ + platform_driver_unregister(&gpio_wdt_driver); +} +module_exit(gpio_wdt_exit); + +MODULE_AUTHOR("Michael Stickel, Florian Fainelli, Mathias Adam"); +MODULE_DESCRIPTION("Driver for GPIO hardware watchdogs"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:gpio-wdt"); --- /dev/null +++ b/include/linux/old_gpio_wdt.h @@ -0,0 +1,21 @@ +/* + * Definitions for the GPIO watchdog driver + * + * Copyright (C) 2013 Mathias Adam + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#ifndef _GPIO_WDT_H_ +#define _GPIO_WDT_H_ + +struct gpio_wdt_platform_data { + int gpio; /* GPIO line number */ + int interval; /* watchdog reset interval in system ticks */ + int first_interval; /* first wd reset interval in system ticks */ +}; + +#endif /* _GPIO_WDT_H_ */