1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/char/watchdog/acquirewdt.c b/drivers/char/watchdog/acquirewdt.c
new file mode 100644
index 00000000000..8f302121741
--- /dev/null
+++ b/drivers/char/watchdog/acquirewdt.c
@@ -0,0 +1,332 @@
+/*
+ *	Acquire Single Board Computer Watchdog Timer driver
+ *
+ *      Based on wdt.c. Original copyright messages:
+ *
+ *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ *				http://www.redhat.com
+ *
+ *	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 Alan Cox nor CymruNet Ltd. admit liability nor provide
+ *	warranty for any of this software. This material is provided
+ *	"AS-IS" and at no charge.
+ *
+ *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
+ *
+ *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
+ *          Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
+ *          Can't add timeout - driver doesn't allow changing value
+ */
+
+/*
+ *	Theory of Operation:
+ *		The Watch-Dog Timer is provided to ensure that standalone
+ *		Systems can always recover from catastrophic conditions that
+ *		caused the CPU to crash. This condition may have occured by
+ *		external EMI or a software bug. When the CPU stops working
+ *		correctly, hardware on the board will either perform a hardware
+ *		reset (cold boot) or a non-maskable interrupt (NMI) to bring the
+ *		system back to a known state.
+ *
+ *		The Watch-Dog Timer is controlled by two I/O Ports.
+ *		  443 hex	- Read	- Enable or refresh the Watch-Dog Timer
+ *		  043 hex	- Read	- Disable the Watch-Dog Timer
+ *
+ *		To enable the Watch-Dog Timer, a read from I/O port 443h must
+ *		be performed. This will enable and activate the countdown timer
+ *		which will eventually time out and either reset the CPU or cause
+ *		an NMI depending on the setting of a jumper. To ensure that this
+ *		reset condition does not occur, the Watch-Dog Timer must be
+ *		periodically refreshed by reading the same I/O port 443h.
+ *		The Watch-Dog Timer is disabled by reading I/O port 043h.
+ *
+ *		The Watch-Dog Timer Time-Out Period is set via jumpers.
+ *		It can be 1, 2, 10, 20, 110 or 220 seconds.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define WATCHDOG_NAME "Acquire WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WATCHDOG_HEARTBEAT 0	/* There is no way to see what the correct time-out period is */
+
+static unsigned long acq_is_open;
+static char expect_close;
+
+/*
+ *	You must set these - there is no sane way to probe for this board.
+ */
+
+static int wdt_stop = 0x43;
+module_param(wdt_stop, int, 0);
+MODULE_PARM_DESC(wdt_stop, "Acquire WDT 'stop' io port (default 0x43)");
+
+static int wdt_start = 0x443;
+module_param(wdt_start, int, 0);
+MODULE_PARM_DESC(wdt_start, "Acquire WDT 'start' io port (default 0x443)");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ *	Kernel methods.
+ */
+
+static void acq_keepalive(void)
+{
+	/* Write a watchdog value */
+	inb_p(wdt_start);
+}
+
+static void acq_stop(void)
+{
+	/* Turn the card off */
+	inb_p(wdt_stop);
+}
+
+/*
+ *	/dev/watchdog handling.
+ */
+
+static ssize_t acq_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	/* See if we got the magic character 'V' and reload the timer */
+	if(count) {
+		if (!nowayout) {
+			size_t i;
+
+			/* note: just in case someone wrote the magic character
+			 * five months ago... */
+			expect_close = 0;
+
+			/* scan to see whether or not we got the magic character */
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 42;
+			}
+		}
+
+		/* Well, anyhow someone wrote to us, we should return that favour */
+		acq_keepalive();
+	}
+	return count;
+}
+
+static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+	unsigned long arg)
+{
+	int options, retval = -EINVAL;
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	static struct watchdog_info ident =
+	{
+		.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+		.firmware_version = 1,
+		.identity = "Acquire WDT",
+	};
+
+	switch(cmd)
+	{
+	case WDIOC_GETSUPPORT:
+	  return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+	  return put_user(0, p);
+
+	case WDIOC_KEEPALIVE:
+	  acq_keepalive();
+	  return 0;
+
+	case WDIOC_GETTIMEOUT:
+	  return put_user(WATCHDOG_HEARTBEAT, p);
+
+	case WDIOC_SETOPTIONS:
+	{
+	    if (get_user(options, p))
+	      return -EFAULT;
+
+	    if (options & WDIOS_DISABLECARD)
+	    {
+	      acq_stop();
+	      retval = 0;
+	    }
+
+	    if (options & WDIOS_ENABLECARD)
+	    {
+	      acq_keepalive();
+	      retval = 0;
+	    }
+
+	    return retval;
+	}
+
+	default:
+	  return -ENOIOCTLCMD;
+	}
+}
+
+static int acq_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &acq_is_open))
+		return -EBUSY;
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	/* Activate */
+	acq_keepalive();
+	return nonseekable_open(inode, file);
+}
+
+static int acq_close(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42) {
+		acq_stop();
+	} else {
+		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+		acq_keepalive();
+	}
+	clear_bit(0, &acq_is_open);
+	expect_close = 0;
+	return 0;
+}
+
+/*
+ *	Notifier for system down
+ */
+
+static int acq_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if(code==SYS_DOWN || code==SYS_HALT) {
+		/* Turn the WDT off */
+		acq_stop();
+	}
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct file_operations acq_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= acq_write,
+	.ioctl		= acq_ioctl,
+	.open		= acq_open,
+	.release	= acq_close,
+};
+
+static struct miscdevice acq_miscdev=
+{
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &acq_fops,
+};
+
+/*
+ *	The WDT card needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block acq_notifier =
+{
+	.notifier_call = acq_notify_sys,
+};
+
+static int __init acq_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "WDT driver for Acquire single board computer initialising.\n");
+
+	if (wdt_stop != wdt_start) {
+		if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
+			printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+				wdt_stop);
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
+		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+			wdt_start);
+		ret = -EIO;
+		goto unreg_stop;
+	}
+
+	ret = register_reboot_notifier(&acq_notifier);
+	if (ret != 0) {
+		printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+			ret);
+		goto unreg_regions;
+	}
+
+	ret = misc_register(&acq_miscdev);
+	if (ret != 0) {
+		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+			WATCHDOG_MINOR, ret);
+		goto unreg_reboot;
+	}
+
+	printk (KERN_INFO PFX "initialized. (nowayout=%d)\n",
+		nowayout);
+
+	return 0;
+
+unreg_reboot:
+	unregister_reboot_notifier(&acq_notifier);
+unreg_regions:
+	release_region(wdt_start, 1);
+unreg_stop:
+	if (wdt_stop != wdt_start)
+		release_region(wdt_stop, 1);
+out:
+	return ret;
+}
+
+static void __exit acq_exit(void)
+{
+	misc_deregister(&acq_miscdev);
+	unregister_reboot_notifier(&acq_notifier);
+	if(wdt_stop != wdt_start)
+		release_region(wdt_stop,1);
+	release_region(wdt_start,1);
+}
+
+module_init(acq_init);
+module_exit(acq_exit);
+
+MODULE_AUTHOR("David Woodhouse");
+MODULE_DESCRIPTION("Acquire Inc. Single Board Computer Watchdog Timer driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);