--- /dev/null
+/*
+ * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
+ *
+ * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>,
+ * All Rights Reserved.
+ *
+ * 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.
+ *
+ * based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/uaccess.h>
+#include <asm/sgi/mc.h>
+
+static unsigned long indydog_alive;
+static DEFINE_SPINLOCK(indydog_lock);
+
+#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void indydog_start(void)
+{
+ spin_lock(&indydog_lock);
+ sgimc->cpuctrl0 |= SGIMC_CCTRL0_WDOG;
+ spin_unlock(&indydog_lock);
+}
+
+static void indydog_stop(void)
+{
+ spin_lock(&indydog_lock);
+ sgimc->cpuctrl0 &= ~SGIMC_CCTRL0_WDOG;
+ spin_unlock(&indydog_lock);
+
+ pr_info("Stopped watchdog timer\n");
+}
+
+static void indydog_ping(void)
+{
+ sgimc->watchdogt = 0;
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+static int indydog_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &indydog_alive))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate timer */
+ indydog_start();
+ indydog_ping();
+
+ pr_info("Started watchdog timer\n");
+
+ return nonseekable_open(inode, file);
+}
+
+static int indydog_release(struct inode *inode, struct file *file)
+{
+ /* Shut off the timer.
+ * Lock it in if it's a module and we defined ...NOWAYOUT */
+ if (!nowayout)
+ indydog_stop(); /* Turn the WDT off */
+ clear_bit(0, &indydog_alive);
+ return 0;
+}
+
+static ssize_t indydog_write(struct file *file, const char *data,
+ size_t len, loff_t *ppos)
+{
+ /* Refresh the timer. */
+ if (len)
+ indydog_ping();
+ return len;
+}
+
+static long indydog_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int options, retval = -EINVAL;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING,
+ .firmware_version = 0,
+ .identity = "Hardware Watchdog for SGI IP22",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user((struct watchdog_info *)arg,
+ &ident, sizeof(ident)))
+ return -EFAULT;
+ return 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, (int *)arg);
+ case WDIOC_SETOPTIONS:
+ {
+ if (get_user(options, (int *)arg))
+ return -EFAULT;
+ if (options & WDIOS_DISABLECARD) {
+ indydog_stop();
+ retval = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ indydog_start();
+ retval = 0;
+ }
+ return retval;
+ }
+ case WDIOC_KEEPALIVE:
+ indydog_ping();
+ return 0;
+ case WDIOC_GETTIMEOUT:
+ return put_user(WATCHDOG_TIMEOUT, (int *)arg);
+ default:
+ return -ENOTTY;
+ }
+}
+
+static int indydog_notify_sys(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ indydog_stop(); /* Turn the WDT off */
+
+ return NOTIFY_DONE;
+}
+
+static const struct file_operations indydog_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = indydog_write,
+ .unlocked_ioctl = indydog_ioctl,
+ .open = indydog_open,
+ .release = indydog_release,
+};
+
+static struct miscdevice indydog_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &indydog_fops,
+};
+
+static struct notifier_block indydog_notifier = {
+ .notifier_call = indydog_notify_sys,
+};
+
+static int __init watchdog_init(void)
+{
+ int ret;
+
+ ret = register_reboot_notifier(&indydog_notifier);
+ if (ret) {
+ pr_err("cannot register reboot notifier (err=%d)\n", ret);
+ return ret;
+ }
+
+ ret = misc_register(&indydog_miscdev);
+ if (ret) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ unregister_reboot_notifier(&indydog_notifier);
+ return ret;
+ }
+
+ pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n");
+
+ return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+ misc_deregister(&indydog_miscdev);
+ unregister_reboot_notifier(&indydog_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
+MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff