[WATCHDOG] iTCO_wdt (Intel TCO Timer) driver

Hardware driver for the intel TCO timer based watchdog devices.
These drivers are included in the Intel 82801 I/O Controller
Hub family (from ICH0 up to ICH7) and in the Intel 6300ESB
controller hub.

This driver will replace the i8xx_tco.c driver.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 706 insertions, 0 deletions

diff --git a/drivers/char/watchdog/iTCO_wdt.c b/drivers/char/watchdog/iTCO_wdt.c
new file mode 100644
index 00000000000..c1a5787fde5
--- /dev/null
+++ b/drivers/char/watchdog/iTCO_wdt.c
@@ -0,0 +1,706 @@
+/*
+ *	intel TCO Watchdog Driver (Used in i82801 and i6300ESB chipsets)
+ *
+ *	(c) Copyright 2006 Wim Van Sebroeck <wim@iguana.be>.
+ *
+ *	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 Wim Van Sebroeck nor Iguana vzw. admit liability nor
+ *	provide warranty for any of this software. This material is
+ *	provided "AS-IS" and at no charge.
+ *
+ *	The TCO watchdog is implemented in the following I/O controller hubs:
+ *	(See the intel documentation on http://developer.intel.com.)
+ *	82801AA  (ICH)       : document number 290655-003, 290677-014,
+ *	82801AB  (ICHO)      : document number 290655-003, 290677-014,
+ *	82801BA  (ICH2)      : document number 290687-002, 298242-027,
+ *	82801BAM (ICH2-M)    : document number 290687-002, 298242-027,
+ *	82801CA  (ICH3-S)    : document number 290733-003, 290739-013,
+ *	82801CAM (ICH3-M)    : document number 290716-001, 290718-007,
+ *	82801DB  (ICH4)      : document number 290744-001, 290745-020,
+ *	82801DBM (ICH4-M)    : document number 252337-001, 252663-005,
+ *	82801E   (C-ICH)     : document number 273599-001, 273645-002,
+ *	82801EB  (ICH5)      : document number 252516-001, 252517-003,
+ *	82801ER  (ICH5R)     : document number 252516-001, 252517-003,
+ *	82801FB  (ICH6)      : document number 301473-002, 301474-007,
+ *	82801FR  (ICH6R)     : document number 301473-002, 301474-007,
+ *	82801FBM (ICH6-M)    : document number 301473-002, 301474-007,
+ *	82801FW  (ICH6W)     : document number 301473-001, 301474-007,
+ *	82801FRW (ICH6RW)    : document number 301473-001, 301474-007,
+ *	82801GB  (ICH7)      : document number 307013-002, 307014-009,
+ *	82801GR  (ICH7R)     : document number 307013-002, 307014-009,
+ *	82801GDH (ICH7DH)    : document number 307013-002, 307014-009,
+ *	82801GBM (ICH7-M)    : document number 307013-002, 307014-009,
+ *	82801GHM (ICH7-M DH) : document number 307013-002, 307014-009,
+ *	6300ESB  (6300ESB)   : document number 300641-003
+ */
+
+/*
+ *	Includes, defines, variables, module parameters, ...
+ */
+
+/* Module and version information */
+#define DRV_NAME        "iTCO_wdt"
+#define DRV_VERSION     "1.00"
+#define DRV_RELDATE     "21-May-2006"
+#define PFX		DRV_NAME ": "
+
+/* Includes */
+#include <linux/config.h>	/* For CONFIG_WATCHDOG_NOWAYOUT/... */
+#include <linux/module.h>	/* For module specific items */
+#include <linux/moduleparam.h>	/* For new moduleparam's */
+#include <linux/types.h>	/* For standard types (like size_t) */
+#include <linux/errno.h>	/* For the -ENODEV/... values */
+#include <linux/kernel.h>	/* For printk/panic/... */
+#include <linux/miscdevice.h>	/* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
+#include <linux/watchdog.h>	/* For the watchdog specific items */
+#include <linux/notifier.h>	/* For notifier support */
+#include <linux/reboot.h>	/* For reboot_notifier stuff */
+#include <linux/init.h>		/* For __init/__exit/... */
+#include <linux/fs.h>		/* For file operations */
+#include <linux/pci.h>		/* For pci functions */
+#include <linux/ioport.h>	/* For io-port access */
+#include <linux/spinlock.h>	/* For spin_lock/spin_unlock/... */
+
+#include <asm/uaccess.h>	/* For copy_to_user/put_user/... */
+#include <asm/io.h>		/* For inb/outb/... */
+
+/* TCO related info */
+enum iTCO_chipsets {
+	TCO_ICH = 0,	/* ICH */
+	TCO_ICH0,	/* ICH0 */
+	TCO_ICH2,	/* ICH2 */
+	TCO_ICH2M,	/* ICH2-M */
+	TCO_ICH3,	/* ICH3-S */
+	TCO_ICH3M,	/* ICH3-M */
+	TCO_ICH4,	/* ICH4 */
+	TCO_ICH4M,	/* ICH4-M */
+	TCO_CICH,	/* C-ICH */
+	TCO_ICH5,	/* ICH5 & ICH5R */
+	TCO_6300ESB,	/* 6300ESB */
+	TCO_ICH6,	/* ICH6 & ICH6R */
+	TCO_ICH6M,	/* ICH6-M */
+	TCO_ICH6W,	/* ICH6W & ICH6RW */
+	TCO_ICH7,	/* ICH7 & ICH7R */
+	TCO_ICH7M,	/* ICH7-M */
+	TCO_ICH7MDH,	/* ICH7-M DH */
+};
+
+static struct {
+	char *name;
+	unsigned int iTCO_version;
+} iTCO_chipset_info[] __devinitdata = {
+	{"ICH", 1},
+	{"ICH0", 1},
+	{"ICH2", 1},
+	{"ICH2-M", 1},
+	{"ICH3-S", 1},
+	{"ICH3-M", 1},
+	{"ICH4", 1},
+	{"ICH4-M", 1},
+	{"C-ICH", 1},
+	{"ICH5 or ICH5R", 1},
+	{"6300ESB", 1},
+	{"ICH6 or ICH6R", 2},
+	{"ICH6-M", 2},
+	{"ICH6W or ICH6RW", 2},
+	{"ICH7 or ICH7R", 2},
+	{"ICH7-M", 2},
+	{"ICH7-M DH", 2},
+	{NULL,0}
+};
+
+/*
+ * This data only exists for exporting the supported PCI ids
+ * via MODULE_DEVICE_TABLE.  We do not actually register a
+ * pci_driver, because the I/O Controller Hub has also other
+ * functions that probably will be registered by other drivers.
+ */
+static struct pci_device_id iTCO_wdt_pci_tbl[] = {
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH     },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH0    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH2    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_10,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH2M   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH3    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_12,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH3M   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH4    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH4M   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801E_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_CICH    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH5    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_6300ESB },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH6    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH6M   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_2,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH6W   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH7    },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH7M   },
+	{ PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_31,	PCI_ANY_ID, PCI_ANY_ID, 0, 0, TCO_ICH7MDH },
+	{ 0, },			/* End of list */
+};
+MODULE_DEVICE_TABLE (pci, iTCO_wdt_pci_tbl);
+
+/* Address definitions for the TCO */
+#define	TCOBASE		iTCO_wdt_private.ACPIBASE + 0x60	/* TCO base address                */
+#define	SMI_EN		iTCO_wdt_private.ACPIBASE + 0x30	/* SMI Control and Enable Register */
+
+#define TCO_RLD		TCOBASE + 0x00	/* TCO Timer Reload and Current Value */
+#define TCOv1_TMR	TCOBASE + 0x01	/* TCOv1 Timer Initial Value	*/
+#define	TCO_DAT_IN	TCOBASE + 0x02	/* TCO Data In Register		*/
+#define	TCO_DAT_OUT	TCOBASE + 0x03	/* TCO Data Out Register	*/
+#define	TCO1_STS	TCOBASE + 0x04	/* TCO1 Status Register		*/
+#define	TCO2_STS	TCOBASE + 0x06	/* TCO2 Status Register		*/
+#define TCO1_CNT	TCOBASE + 0x08	/* TCO1 Control Register	*/
+#define TCO2_CNT	TCOBASE + 0x0a	/* TCO2 Control Register	*/
+#define TCOv2_TMR	TCOBASE + 0x12	/* TCOv2 Timer Initial Value	*/
+
+/* internal variables */
+static unsigned long is_active;
+static char expect_release;
+static struct {				/* this is private data for the iTCO_wdt device */
+	unsigned int iTCO_version;	/* TCO version/generation */
+	unsigned long ACPIBASE;		/* The cards ACPIBASE address (TCOBASE = ACPIBASE+0x60) */
+	unsigned long __iomem *gcs;	/* NO_REBOOT flag is Memory-Mapped GCS register bit 5 (TCO version 2) */
+	spinlock_t io_lock;		/* the lock for io operations */
+	struct pci_dev *pdev;		/* the PCI-device */
+} iTCO_wdt_private;
+
+/* module parameters */
+#define WATCHDOG_HEARTBEAT 30	/* 30 sec default heartbeat */
+static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39 (TCO v1) or 613 (TCO v2), default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ * Some TCO specific functions
+ */
+
+static inline unsigned int seconds_to_ticks(int seconds)
+{
+	/* the internal timer is stored as ticks which decrement
+	 * every 0.6 seconds */
+	return (seconds * 10) / 6;
+}
+
+static void iTCO_wdt_set_NO_REBOOT_bit(void)
+{
+	u32 val32;
+
+	/* Set the NO_REBOOT bit: this disables reboots */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		val32 = readl(iTCO_wdt_private.gcs);
+		val32 |= 0x00000020;
+		writel(val32, iTCO_wdt_private.gcs);
+	} else if (iTCO_wdt_private.iTCO_version == 1) {
+		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
+		val32 |= 0x00000002;
+		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);
+	}
+}
+
+static int iTCO_wdt_unset_NO_REBOOT_bit(void)
+{
+	int ret = 0;
+	u32 val32;
+
+	/* Unset the NO_REBOOT bit: this enables reboots */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		val32 = readl(iTCO_wdt_private.gcs);
+		val32 &= 0xffffffdf;
+		writel(val32, iTCO_wdt_private.gcs);
+
+		val32 = readl(iTCO_wdt_private.gcs);
+		if (val32 & 0x00000020)
+			ret = -EIO;
+	} else if (iTCO_wdt_private.iTCO_version == 1) {
+		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
+		val32 &= 0xfffffffd;
+		pci_write_config_dword(iTCO_wdt_private.pdev, 0xd4, val32);
+
+		pci_read_config_dword(iTCO_wdt_private.pdev, 0xd4, &val32);
+		if (val32 & 0x00000002)
+			ret = -EIO;
+	}
+
+	return ret; /* returns: 0 = OK, -EIO = Error */
+}
+
+static int iTCO_wdt_start(void)
+{
+	unsigned int val;
+
+	spin_lock(&iTCO_wdt_private.io_lock);
+
+	/* disable chipset's NO_REBOOT bit */
+	if (iTCO_wdt_unset_NO_REBOOT_bit()) {
+		printk(KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
+		return -EIO;
+	}
+
+	/* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
+	val = inw(TCO1_CNT);
+	val &= 0xf7ff;
+	outw(val, TCO1_CNT);
+	val = inw(TCO1_CNT);
+	spin_unlock(&iTCO_wdt_private.io_lock);
+
+	if (val & 0x0800)
+		return -1;
+	return 0;
+}
+
+static int iTCO_wdt_stop(void)
+{
+	unsigned int val;
+
+	spin_lock(&iTCO_wdt_private.io_lock);
+
+	/* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
+	val = inw(TCO1_CNT);
+	val |= 0x0800;
+	outw(val, TCO1_CNT);
+	val = inw(TCO1_CNT);
+
+	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
+	iTCO_wdt_set_NO_REBOOT_bit();
+
+	spin_unlock(&iTCO_wdt_private.io_lock);
+
+	if ((val & 0x0800) == 0)
+		return -1;
+	return 0;
+}
+
+static int iTCO_wdt_keepalive(void)
+{
+	spin_lock(&iTCO_wdt_private.io_lock);
+
+	/* Reload the timer by writing to the TCO Timer Counter register */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		outw(0x01, TCO_RLD);
+	} else if (iTCO_wdt_private.iTCO_version == 1) {
+		outb(0x01, TCO_RLD);
+	}
+
+	spin_unlock(&iTCO_wdt_private.io_lock);
+	return 0;
+}
+
+static int iTCO_wdt_set_heartbeat(int t)
+{
+	unsigned int val16;
+	unsigned char val8;
+	unsigned int tmrval;
+
+	tmrval = seconds_to_ticks(t);
+	/* from the specs: */
+	/* "Values of 0h-3h are ignored and should not be attempted" */
+	if (tmrval < 0x04)
+		return -EINVAL;
+	if (((iTCO_wdt_private.iTCO_version == 2) && (tmrval > 0x3ff)) ||
+	    ((iTCO_wdt_private.iTCO_version == 1) && (tmrval > 0x03f)))
+		return -EINVAL;
+
+	/* Write new heartbeat to watchdog */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		spin_lock(&iTCO_wdt_private.io_lock);
+		val16 = inw(TCOv2_TMR);
+		val16 &= 0xfc00;
+		val16 |= tmrval;
+		outw(val16, TCOv2_TMR);
+		val16 = inw(TCOv2_TMR);
+		spin_unlock(&iTCO_wdt_private.io_lock);
+
+		if ((val16 & 0x3ff) != tmrval)
+			return -EINVAL;
+	} else if (iTCO_wdt_private.iTCO_version == 1) {
+		spin_lock(&iTCO_wdt_private.io_lock);
+		val8 = inb(TCOv1_TMR);
+		val8 &= 0xc0;
+		val8 |= (tmrval & 0xff);
+		outb(val8, TCOv1_TMR);
+		val8 = inb(TCOv1_TMR);
+		spin_unlock(&iTCO_wdt_private.io_lock);
+
+		if ((val8 & 0x3f) != tmrval)
+			return -EINVAL;
+	}
+
+	heartbeat = t;
+	return 0;
+}
+
+static int iTCO_wdt_get_timeleft (int *time_left)
+{
+	unsigned int val16;
+	unsigned char val8;
+
+	/* read the TCO Timer */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		spin_lock(&iTCO_wdt_private.io_lock);
+		val16 = inw(TCO_RLD);
+		val16 &= 0x3ff;
+		spin_unlock(&iTCO_wdt_private.io_lock);
+
+		*time_left = (val16 * 6) / 10;
+	} else if (iTCO_wdt_private.iTCO_version == 1) {
+		spin_lock(&iTCO_wdt_private.io_lock);
+		val8 = inb(TCO_RLD);
+		val8 &= 0x3f;
+		spin_unlock(&iTCO_wdt_private.io_lock);
+
+		*time_left = (val8 * 6) / 10;
+	}
+	return 0;
+}
+
+/*
+ *	/dev/watchdog handling
+ */
+
+static int iTCO_wdt_open (struct inode *inode, struct file *file)
+{
+	/* /dev/watchdog can only be opened once */
+	if (test_and_set_bit(0, &is_active))
+		return -EBUSY;
+
+	/*
+	 *      Reload and activate timer
+	 */
+	iTCO_wdt_keepalive();
+	iTCO_wdt_start();
+	return nonseekable_open(inode, file);
+}
+
+static int iTCO_wdt_release (struct inode *inode, struct file *file)
+{
+	/*
+	 *      Shut off the timer.
+	 */
+	if (expect_release == 42) {
+		iTCO_wdt_stop();
+	} else {
+		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+		iTCO_wdt_keepalive();
+	}
+	clear_bit(0, &is_active);
+	expect_release = 0;
+	return 0;
+}
+
+static ssize_t iTCO_wdt_write (struct file *file, const char __user *data,
+			      size_t len, loff_t * ppos)
+{
+	/* See if we got the magic character 'V' and reload the timer */
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			/* note: just in case someone wrote the magic character
+			 * five months ago... */
+			expect_release = 0;
+
+			/* scan to see whether or not we got the magic character */
+			for (i = 0; i != len; i++) {
+				char c;
+				if (get_user(c, data+i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_release = 42;
+			}
+		}
+
+		/* someone wrote to us, we should reload the timer */
+		iTCO_wdt_keepalive();
+	}
+	return len;
+}
+
+static int iTCO_wdt_ioctl (struct inode *inode, struct file *file,
+			  unsigned int cmd, unsigned long arg)
+{
+	int new_options, retval = -EINVAL;
+	int new_heartbeat;
+	int time_left;
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	static struct watchdog_info ident = {
+		.options =		WDIOF_SETTIMEOUT |
+					WDIOF_KEEPALIVEPING |
+					WDIOF_MAGICCLOSE,
+		.firmware_version =	0,
+		.identity =		DRV_NAME,
+	};
+
+	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:
+			iTCO_wdt_keepalive();
+			return 0;
+
+		case WDIOC_SETOPTIONS:
+		{
+			if (get_user(new_options, p))
+				return -EFAULT;
+
+			if (new_options & WDIOS_DISABLECARD) {
+				iTCO_wdt_stop();
+				retval = 0;
+			}
+
+			if (new_options & WDIOS_ENABLECARD) {
+				iTCO_wdt_keepalive();
+				iTCO_wdt_start();
+				retval = 0;
+			}
+
+			return retval;
+		}
+
+		case WDIOC_SETTIMEOUT:
+		{
+			if (get_user(new_heartbeat, p))
+				return -EFAULT;
+
+			if (iTCO_wdt_set_heartbeat(new_heartbeat))
+				return -EINVAL;
+
+			iTCO_wdt_keepalive();
+			/* Fall */
+		}
+
+		case WDIOC_GETTIMEOUT:
+			return put_user(heartbeat, p);
+
+		case WDIOC_GETTIMELEFT:
+		{
+			if (iTCO_wdt_get_timeleft(&time_left))
+				return -EINVAL;
+
+			return put_user(time_left, p);
+		}
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+}
+
+/*
+ *	Notify system
+ */
+
+static int iTCO_wdt_notify_sys (struct notifier_block *this, unsigned long code, void *unused)
+{
+	if (code==SYS_DOWN || code==SYS_HALT) {
+		/* Turn the WDT off */
+		iTCO_wdt_stop();
+	}
+
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct file_operations iTCO_wdt_fops = {
+	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+	.write =	iTCO_wdt_write,
+	.ioctl =	iTCO_wdt_ioctl,
+	.open =		iTCO_wdt_open,
+	.release =	iTCO_wdt_release,
+};
+
+static struct miscdevice iTCO_wdt_miscdev = {
+	.minor =	WATCHDOG_MINOR,
+	.name =		"watchdog",
+	.fops =		&iTCO_wdt_fops,
+};
+
+static struct notifier_block iTCO_wdt_notifier = {
+	.notifier_call =	iTCO_wdt_notify_sys,
+};
+
+/*
+ *	Init & exit routines
+ */
+
+static int __init iTCO_wdt_init(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	int ret;
+	u32 base_address;
+	unsigned long RCBA;
+	unsigned long val32;
+
+	/*
+	 *      Find the ACPI/PM base I/O address which is the base
+	 *      for the TCO registers (TCOBASE=ACPIBASE + 0x60)
+	 *      ACPIBASE is bits [15:7] from 0x40-0x43
+	 */
+	pci_read_config_dword(pdev, 0x40, &base_address);
+	base_address &= 0x00007f80;
+	if (base_address == 0x00000000) {
+		/* Something's wrong here, ACPIBASE has to be set */
+		printk(KERN_ERR PFX "failed to get TCOBASE address\n");
+		return -ENODEV;
+	}
+	iTCO_wdt_private.iTCO_version = iTCO_chipset_info[ent->driver_data].iTCO_version;
+	iTCO_wdt_private.ACPIBASE = base_address;
+	iTCO_wdt_private.pdev = pdev;
+
+	/* Get the Memory-Mapped GCS register, we need it for the NO_REBOOT flag (TCO v2) */
+	/* To get access to it you have to read RCBA from PCI Config space 0xf0
+	   and use it as base. GCS = RCBA + ICH6_GCS(0x3410). */
+	if (iTCO_wdt_private.iTCO_version == 2) {
+		pci_read_config_dword(pdev, 0xf0, &base_address);
+		RCBA = base_address & 0xffffc000;
+		iTCO_wdt_private.gcs = ioremap((RCBA + 0x3410),4);
+	}
+
+	/* Check chipset's NO_REBOOT bit */
+	if (iTCO_wdt_unset_NO_REBOOT_bit()) {
+		printk(KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
+		ret = -ENODEV;	/* Cannot reset NO_REBOOT bit */
+		goto out;
+	}
+
+	/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
+	iTCO_wdt_set_NO_REBOOT_bit();
+
+	/* Set the TCO_EN bit in SMI_EN register */
+	if (!request_region(SMI_EN, 4, "iTCO_wdt")) {
+		printk(KERN_ERR PFX "I/O address 0x%04lx already in use\n",
+			SMI_EN );
+		ret = -EIO;
+		goto out;
+	}
+	val32 = inl(SMI_EN);
+	val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
+	outl(val32, SMI_EN);
+	release_region(SMI_EN, 4);
+
+	/* The TCO I/O registers reside in a 32-byte range pointed to by the TCOBASE value */
+	if (!request_region (TCOBASE, 0x20, "iTCO_wdt")) {
+		printk (KERN_ERR PFX "I/O address 0x%04lx already in use\n",
+			TCOBASE);
+		ret = -EIO;
+		goto out;
+	}
+
+	printk(KERN_INFO PFX "Found a %s TCO device (Version=%d, TCOBASE=0x%04lx)\n",
+		iTCO_chipset_info[ent->driver_data].name,
+		iTCO_chipset_info[ent->driver_data].iTCO_version,
+		TCOBASE);
+
+	/* Clear out the (probably old) status */
+	outb(0, TCO1_STS);
+	outb(3, TCO2_STS);
+
+	/* Make sure the watchdog is not running */
+	iTCO_wdt_stop();
+
+	/* Check that the heartbeat value is within it's range ; if not reset to the default */
+	if (iTCO_wdt_set_heartbeat(heartbeat)) {
+		iTCO_wdt_set_heartbeat(WATCHDOG_HEARTBEAT);
+		printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39 (TCO v1) or 613 (TCO v2), using %d\n",
+			heartbeat);
+	}
+
+	ret = register_reboot_notifier(&iTCO_wdt_notifier);
+	if (ret != 0) {
+		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+			ret);
+		goto unreg_region;
+	}
+
+	ret = misc_register(&iTCO_wdt_miscdev);
+	if (ret != 0) {
+		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+			WATCHDOG_MINOR, ret);
+		goto unreg_notifier;
+	}
+
+	printk (KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
+		heartbeat, nowayout);
+
+	return 0;
+
+unreg_notifier:
+	unregister_reboot_notifier(&iTCO_wdt_notifier);
+unreg_region:
+	release_region (TCOBASE, 0x20);
+out:
+	if (iTCO_wdt_private.iTCO_version == 2)
+		iounmap(iTCO_wdt_private.gcs);
+	iTCO_wdt_private.ACPIBASE = 0;
+	return ret;
+}
+
+static void __exit iTCO_wdt_cleanup(void)
+{
+	/* Stop the timer before we leave */
+	if (!nowayout)
+		iTCO_wdt_stop();
+
+	/* Deregister */
+	misc_deregister(&iTCO_wdt_miscdev);
+	unregister_reboot_notifier(&iTCO_wdt_notifier);
+	release_region(TCOBASE, 0x20);
+	if (iTCO_wdt_private.iTCO_version == 2)
+		iounmap(iTCO_wdt_private.gcs);
+}
+
+static int __init iTCO_wdt_init_module(void)
+{
+	int found = 0;
+	struct pci_dev *pdev = NULL;
+	const struct pci_device_id *ent;
+
+	spin_lock_init(&iTCO_wdt_private.io_lock);
+
+	for_each_pci_dev(pdev) {
+		ent = pci_match_id(iTCO_wdt_pci_tbl, pdev);
+		if (ent) {
+			if (!(iTCO_wdt_init(pdev, ent))) {
+				found++;
+				break;
+			}
+		}
+	}
+
+	if (!found) {
+		printk(KERN_INFO PFX "No card detected\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void __exit iTCO_wdt_cleanup_module(void)
+{
+	if (iTCO_wdt_private.ACPIBASE)
+		iTCO_wdt_cleanup();
+
+	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
+}
+
+module_init(iTCO_wdt_init_module);
+module_exit(iTCO_wdt_cleanup_module);
+
+MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
+MODULE_DESCRIPTION("Intel TCO WatchDog Timer Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);