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kernel: add generic GPIO watchdog driver

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This is used on Huawei E970 (brcm47xx).

Signed-off-by: Mathias Adam <m.adam--openwrt@adamis.de>

SVN-Revision: 38010
This commit is contained in:
Hauke Mehrtens 2013-09-16 21:07:52 +00:00
parent 880be9ca2f
commit 0294358e11
2 changed files with 361 additions and 0 deletions
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1
target/linux/generic/config-3.10
View file

@ -1000,6 +1000,7 @@ CONFIG_GENERIC_TIME=y
# CONFIG_GPIO_SYSFS is not set
# CONFIG_GPIO_TS5500 is not set
# CONFIG_GPIO_VX855 is not set
# CONFIG_GPIO_WDT is not set
# CONFIG_GPIO_XILINX is not set
# CONFIG_GREENASIA_FF is not set
# CONFIG_HAMACHI is not set

360
target/linux/generic/patches-3.10/990-gpio_wdt.patch Normal file
View file

@ -0,0 +1,360 @@
This generic GPIO watchdog is used on Huawei E970 (brcm47xx)
Signed-off-by: Mathias Adam <m.adam--openwrt@adamis.de>
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1035,6 +1035,15 @@ 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 PNX833X_WDT
tristate "PNX833x Hardware Watchdog"
depends on SOC_PNX8335
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -127,6 +127,7 @@ 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-$(CONFIG_GPIO_WDT) += gpio_wdt.o
obj-$(CONFIG_PNX833X_WDT) += pnx833x_wdt.o
obj-$(CONFIG_SIBYTE_WDOG) += sb_wdog.o
obj-$(CONFIG_AR7_WDT) += ar7_wdt.o
--- /dev/null
+++ b/drivers/watchdog/gpio_wdt.c
@@ -0,0 +1,301 @@
+/*
+ * Driver for GPIO-controlled Hardware Watchdogs.
+ *
+ * Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
+ *
+ * Replaces mtx1_wdt (driver for the MTX-1 Watchdog):
+ *
+ * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
+ * All Rights Reserved.
+ * http://www.4g-systems.biz
+ *
+ * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
+ *
+ * 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 <info@4g-systems.biz>
+ *
+ * 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 <m.adam--linux@adamis.de>
+ * 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 <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/gpio.h>
+#include <linux/gpio_wdt.h>
+
+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(unsigned long 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);
+ setup_timer(&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",
+ .driver.owner = THIS_MODULE,
+};
+
+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/gpio_wdt.h
@@ -0,0 +1,21 @@
+/*
+ * Definitions for the GPIO watchdog driver
+ *
+ * Copyright (C) 2013 Mathias Adam <m.adam--linux@adamis.de>
+ *
+ * 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_ */