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path: root/drivers/char/watchdog/indydog.c
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Diffstat (limited to 'drivers/char/watchdog/indydog.c')
-rw-r--r--drivers/char/watchdog/indydog.c221
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/char/watchdog/indydog.c b/drivers/char/watchdog/indydog.c
new file mode 100644
index 000000000000..6af2c799b57e
--- /dev/null
+++ b/drivers/char/watchdog/indydog.c
@@ -0,0 +1,221 @@
+/*
+ * 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@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/config.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 <asm/uaccess.h>
+#include <asm/sgi/mc.h>
+
+#define PFX "indydog: "
+static int indydog_alive;
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+static void indydog_start(void)
+{
+ u32 mc_ctrl0 = sgimc->cpuctrl0;
+
+ mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG;
+ sgimc->cpuctrl0 = mc_ctrl0;
+}
+
+static void indydog_stop(void)
+{
+ u32 mc_ctrl0 = sgimc->cpuctrl0;
+
+ mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
+ sgimc->cpuctrl0 = mc_ctrl0;
+
+ printk(KERN_INFO PFX "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 (indydog_alive)
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate timer */
+ indydog_start();
+ indydog_ping();
+
+ indydog_alive = 1;
+ printk(KERN_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 */
+
+ indydog_alive = 0;
+
+ 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 int indydog_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int options, retval = -EINVAL;
+ static struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = "Hardware Watchdog for SGI IP22",
+ };
+
+ switch (cmd) {
+ default:
+ return -ENOIOCTLCMD;
+ 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_KEEPALIVE:
+ indydog_ping();
+ return 0;
+ case WDIOC_GETTIMEOUT:
+ return put_user(WATCHDOG_TIMEOUT,(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;
+ }
+ }
+}
+
+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 struct file_operations indydog_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = indydog_write,
+ .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 char banner[] __initdata =
+ KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";
+
+static int __init watchdog_init(void)
+{
+ int ret;
+
+ ret = register_reboot_notifier(&indydog_notifier);
+ if (ret) {
+ printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ ret);
+ return ret;
+ }
+
+ ret = misc_register(&indydog_miscdev);
+ if (ret) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ unregister_reboot_notifier(&indydog_notifier);
+ return ret;
+ }
+
+ printk(banner);
+
+ 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");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);