]> bbs.cooldavid.org Git - net-next-2.6.git/commitdiff
watchdog: f71808e_wdt: new watchdog driver for Fintek F71808E and F71882FG
authorGiel van Schijndel <me@mortis.eu>
Sun, 1 Aug 2010 13:30:55 +0000 (15:30 +0200)
committerWim Van Sebroeck <wim@iguana.be>
Sun, 8 Aug 2010 18:21:42 +0000 (18:21 +0000)
Add a new watchdog driver for the Fintek F71808E and F71882FG Super I/O
controllers.

Signed-off-by: Giel van Schijndel <me@mortis.eu>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/f71808e_wdt.c [new file with mode: 0644]

index b04b1846893265563aaa9abee1a589c35d8ddc42..910e09f49b36887330c258f70f2ac8e28b7bfad4 100644 (file)
@@ -401,6 +401,17 @@ config ALIM7101_WDT
 
          Most people will say N.
 
+config F71808E_WDT
+       tristate "Fintek F71808E and F71882FG Watchdog"
+       depends on X86 && EXPERIMENTAL
+       help
+         This is the driver for the hardware watchdog on the Fintek
+         F71808E and F71882FG Super I/O controllers.
+
+         You can compile this driver directly into the kernel, or use
+         it as a module.  The module will be called f71808e_wdt.
+
+
 config GEODE_WDT
        tristate "AMD Geode CS5535/CS5536 Watchdog"
        depends on CS5535_MFGPT
index e30289a5e36776413e0211dea6bd24745a59b32c..0010ae55556a40ff656ae51b615d0268fb5941f2 100644 (file)
@@ -66,6 +66,7 @@ obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
 obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
 obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o
 obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o
+obj-$(CONFIG_F71808E_WDT) += f71808e_wdt.o
 obj-$(CONFIG_GEODE_WDT) += geodewdt.o
 obj-$(CONFIG_SC520_WDT) += sc520_wdt.o
 obj-$(CONFIG_SBC_FITPC2_WATCHDOG) += sbc_fitpc2_wdt.o
diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
new file mode 100644 (file)
index 0000000..7e5c266
--- /dev/null
@@ -0,0 +1,768 @@
+/***************************************************************************
+ *   Copyright (C) 2006 by Hans Edgington <hans@edgington.nl>              *
+ *   Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com>           *
+ *   Copyright (C) 2010 Giel van Schijndel <me@mortis.eu>                  *
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ ***************************************************************************/
+
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+#define DRVNAME "f71808e_wdt"
+
+#define SIO_F71808FG_LD_WDT    0x07    /* Watchdog timer logical device */
+#define SIO_UNLOCK_KEY         0x87    /* Key to enable Super-I/O */
+#define SIO_LOCK_KEY           0xAA    /* Key to diasble Super-I/O */
+
+#define SIO_REG_LDSEL          0x07    /* Logical device select */
+#define SIO_REG_DEVID          0x20    /* Device ID (2 bytes) */
+#define SIO_REG_DEVREV         0x22    /* Device revision */
+#define SIO_REG_MANID          0x23    /* Fintek ID (2 bytes) */
+#define SIO_REG_ENABLE         0x30    /* Logical device enable */
+#define SIO_REG_ADDR           0x60    /* Logical device address (2 bytes) */
+
+#define SIO_FINTEK_ID          0x1934  /* Manufacturers ID */
+#define SIO_F71808_ID          0x0901  /* Chipset ID */
+#define SIO_F71858_ID          0x0507  /* Chipset ID */
+#define SIO_F71862_ID          0x0601  /* Chipset ID */
+#define SIO_F71882_ID          0x0541  /* Chipset ID */
+#define SIO_F71889_ID          0x0723  /* Chipset ID */
+
+#define        F71882FG_REG_START              0x01
+
+#define F71808FG_REG_WDO_CONF          0xf0
+#define F71808FG_REG_WDT_CONF          0xf5
+#define F71808FG_REG_WD_TIME           0xf6
+
+#define F71808FG_FLAG_WDOUT_EN         7
+
+#define F71808FG_FLAG_WDTMOUT_STS      5
+#define F71808FG_FLAG_WD_EN            5
+#define F71808FG_FLAG_WD_PULSE         4
+#define F71808FG_FLAG_WD_UNIT          3
+
+/* Default values */
+#define WATCHDOG_TIMEOUT       60      /* 1 minute default timeout */
+#define WATCHDOG_MAX_TIMEOUT   (60 * 255)
+#define WATCHDOG_PULSE_WIDTH   125     /* 125 ms, default pulse width for
+                                          watchdog signal */
+
+static unsigned short force_id;
+module_param(force_id, ushort, 0);
+MODULE_PARM_DESC(force_id, "Override the detected device ID");
+
+static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
+static int timeout = 60;       /* default timeout in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+       "Watchdog timeout in seconds. 1<= timeout <="
+                       __MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
+                       __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
+module_param(pulse_width, uint, 0);
+MODULE_PARM_DESC(pulse_width,
+       "Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
+                       " (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0444);
+MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
+
+static unsigned int start_withtimeout;
+module_param(start_withtimeout, uint, 0);
+MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
+       " given initial timeout. Zero (default) disables this feature.");
+
+enum chips { f71808fg, f71858fg, f71862fg, f71882fg, f71889fg };
+
+static const char *f71808e_names[] = {
+       "f71808fg",
+       "f71858fg",
+       "f71862fg",
+       "f71882fg",
+       "f71889fg",
+};
+
+/* Super-I/O Function prototypes */
+static inline int superio_inb(int base, int reg);
+static inline int superio_inw(int base, int reg);
+static inline void superio_outb(int base, int reg, u8 val);
+static inline void superio_set_bit(int base, int reg, int bit);
+static inline void superio_clear_bit(int base, int reg, int bit);
+static inline int superio_enter(int base);
+static inline void superio_select(int base, int ld);
+static inline void superio_exit(int base);
+
+struct watchdog_data {
+       unsigned short  sioaddr;
+       enum chips      type;
+       unsigned long   opened;
+       struct mutex    lock;
+       char            expect_close;
+       struct watchdog_info ident;
+
+       unsigned short  timeout;
+       u8              timer_val;      /* content for the wd_time register */
+       char            minutes_mode;
+       u8              pulse_val;      /* pulse width flag */
+       char            pulse_mode;     /* enable pulse output mode? */
+       char            caused_reboot;  /* last reboot was by the watchdog */
+};
+
+static struct watchdog_data watchdog = {
+       .lock = __MUTEX_INITIALIZER(watchdog.lock),
+};
+
+/* Super I/O functions */
+static inline int superio_inb(int base, int reg)
+{
+       outb(reg, base);
+       return inb(base + 1);
+}
+
+static int superio_inw(int base, int reg)
+{
+       int val;
+       val  = superio_inb(base, reg) << 8;
+       val |= superio_inb(base, reg + 1);
+       return val;
+}
+
+static inline void superio_outb(int base, int reg, u8 val)
+{
+       outb(reg, base);
+       outb(val, base + 1);
+}
+
+static inline void superio_set_bit(int base, int reg, int bit)
+{
+       unsigned long val = superio_inb(base, reg);
+       __set_bit(bit, &val);
+       superio_outb(base, reg, val);
+}
+
+static inline void superio_clear_bit(int base, int reg, int bit)
+{
+       unsigned long val = superio_inb(base, reg);
+       __clear_bit(bit, &val);
+       superio_outb(base, reg, val);
+}
+
+static inline int superio_enter(int base)
+{
+       /* Don't step on other drivers' I/O space by accident */
+       if (!request_muxed_region(base, 2, DRVNAME)) {
+               printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
+                               (int)base);
+               return -EBUSY;
+       }
+
+       /* according to the datasheet the key must be send twice! */
+       outb(SIO_UNLOCK_KEY, base);
+       outb(SIO_UNLOCK_KEY, base);
+
+       return 0;
+}
+
+static inline void superio_select(int base, int ld)
+{
+       outb(SIO_REG_LDSEL, base);
+       outb(ld, base + 1);
+}
+
+static inline void superio_exit(int base)
+{
+       outb(SIO_LOCK_KEY, base);
+       release_region(base, 2);
+}
+
+static int watchdog_set_timeout(int timeout)
+{
+       if (timeout <= 0
+        || timeout >  max_timeout) {
+               printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
+               return -EINVAL;
+       }
+
+       mutex_lock(&watchdog.lock);
+
+       watchdog.timeout = timeout;
+       if (timeout > 0xff) {
+               watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
+               watchdog.minutes_mode = true;
+       } else {
+               watchdog.timer_val = timeout;
+               watchdog.minutes_mode = false;
+       }
+
+       mutex_unlock(&watchdog.lock);
+
+       return 0;
+}
+
+static int watchdog_set_pulse_width(unsigned int pw)
+{
+       int err = 0;
+
+       mutex_lock(&watchdog.lock);
+
+       if        (pw <=    1) {
+               watchdog.pulse_val = 0;
+       } else if (pw <=   25) {
+               watchdog.pulse_val = 1;
+       } else if (pw <=  125) {
+               watchdog.pulse_val = 2;
+       } else if (pw <= 5000) {
+               watchdog.pulse_val = 3;
+       } else {
+               printk(KERN_ERR DRVNAME ": pulse width out of range\n");
+               err = -EINVAL;
+               goto exit_unlock;
+       }
+
+       watchdog.pulse_mode = pw;
+
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+       return err;
+}
+
+static int watchdog_keepalive(void)
+{
+       int err = 0;
+
+       mutex_lock(&watchdog.lock);
+       err = superio_enter(watchdog.sioaddr);
+       if (err)
+               goto exit_unlock;
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+       if (watchdog.minutes_mode)
+               /* select minutes for timer units */
+               superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                               F71808FG_FLAG_WD_UNIT);
+       else
+               /* select seconds for timer units */
+               superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                               F71808FG_FLAG_WD_UNIT);
+
+       /* Set timer value */
+       superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
+                          watchdog.timer_val);
+
+       superio_exit(watchdog.sioaddr);
+
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+       return err;
+}
+
+static int watchdog_start(void)
+{
+       /* Make sure we don't die as soon as the watchdog is enabled below */
+       int err = watchdog_keepalive();
+       if (err)
+               return err;
+
+       mutex_lock(&watchdog.lock);
+       err = superio_enter(watchdog.sioaddr);
+       if (err)
+               goto exit_unlock;
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+       /* Watchdog pin configuration */
+       switch (watchdog.type) {
+       case f71808fg:
+               /* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
+               superio_clear_bit(watchdog.sioaddr, 0x2a, 3);
+               superio_clear_bit(watchdog.sioaddr, 0x2b, 3);
+               break;
+
+       case f71882fg:
+               /* Set pin 56 to WDTRST# */
+               superio_set_bit(watchdog.sioaddr, 0x29, 1);
+               break;
+
+       default:
+               /*
+                * 'default' label to shut up the compiler and catch
+                * programmer errors
+                */
+               err = -ENODEV;
+               goto exit_superio;
+       }
+
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+       superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
+       superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
+                       F71808FG_FLAG_WDOUT_EN);
+
+       superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                       F71808FG_FLAG_WD_EN);
+
+       if (watchdog.pulse_mode) {
+               /* Select "pulse" output mode with given duration */
+               u8 wdt_conf = superio_inb(watchdog.sioaddr,
+                               F71808FG_REG_WDT_CONF);
+
+               /* Set WD_PSWIDTH bits (1:0) */
+               wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
+               /* Set WD_PULSE to "pulse" mode */
+               wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
+
+               superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                               wdt_conf);
+       } else {
+               /* Select "level" output mode */
+               superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                               F71808FG_FLAG_WD_PULSE);
+       }
+
+exit_superio:
+       superio_exit(watchdog.sioaddr);
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+
+       return err;
+}
+
+static int watchdog_stop(void)
+{
+       int err = 0;
+
+       mutex_lock(&watchdog.lock);
+       err = superio_enter(watchdog.sioaddr);
+       if (err)
+               goto exit_unlock;
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+       superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
+                       F71808FG_FLAG_WD_EN);
+
+       superio_exit(watchdog.sioaddr);
+
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+
+       return err;
+}
+
+static int watchdog_get_status(void)
+{
+       int status = 0;
+
+       mutex_lock(&watchdog.lock);
+       status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
+       mutex_unlock(&watchdog.lock);
+
+       return status;
+}
+
+static bool watchdog_is_running(void)
+{
+       /*
+        * if we fail to determine the watchdog's status assume it to be
+        * running to be on the safe side
+        */
+       bool is_running = true;
+
+       mutex_lock(&watchdog.lock);
+       if (superio_enter(watchdog.sioaddr))
+               goto exit_unlock;
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+       is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
+               && (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
+                       & F71808FG_FLAG_WD_EN);
+
+       superio_exit(watchdog.sioaddr);
+
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+       return is_running;
+}
+
+/* /dev/watchdog api */
+
+static int watchdog_open(struct inode *inode, struct file *file)
+{
+       int err;
+
+       /* If the watchdog is alive we don't need to start it again */
+       if (test_and_set_bit(0, &watchdog.opened))
+               return -EBUSY;
+
+       err = watchdog_start();
+       if (err) {
+               clear_bit(0, &watchdog.opened);
+               return err;
+       }
+
+       if (nowayout)
+               __module_get(THIS_MODULE);
+
+       watchdog.expect_close = 0;
+       return nonseekable_open(inode, file);
+}
+
+static int watchdog_release(struct inode *inode, struct file *file)
+{
+       clear_bit(0, &watchdog.opened);
+
+       if (!watchdog.expect_close) {
+               watchdog_keepalive();
+               printk(KERN_CRIT DRVNAME
+                       ": Unexpected close, not stopping watchdog!\n");
+       } else if (!nowayout) {
+               watchdog_stop();
+       }
+       return 0;
+}
+
+/*
+ *      watchdog_write:
+ *      @file: file handle to the watchdog
+ *      @buf: buffer to write
+ *      @count: count of bytes
+ *      @ppos: pointer to the position to write. No seeks allowed
+ *
+ *      A write to a watchdog device is defined as a keepalive signal. Any
+ *      write of data will do, as we we don't define content meaning.
+ */
+
+static ssize_t watchdog_write(struct file *file, const char __user *buf,
+                           size_t count, loff_t *ppos)
+{
+       if (count) {
+               if (!nowayout) {
+                       size_t i;
+
+                       /* In case it was set long ago */
+                       bool expect_close = false;
+
+                       for (i = 0; i != count; i++) {
+                               char c;
+                               if (get_user(c, buf + i))
+                                       return -EFAULT;
+                               expect_close = (c == 'V');
+                       }
+
+                       /* Properly order writes across fork()ed processes */
+                       mutex_lock(&watchdog.lock);
+                       watchdog.expect_close = expect_close;
+                       mutex_unlock(&watchdog.lock);
+               }
+
+               /* someone wrote to us, we should restart timer */
+               watchdog_keepalive();
+       }
+       return count;
+}
+
+/*
+ *      watchdog_ioctl:
+ *      @inode: inode of the device
+ *      @file: file handle to the device
+ *      @cmd: watchdog command
+ *      @arg: argument pointer
+ *
+ *      The watchdog API defines a common set of functions for all watchdogs
+ *      according to their available features.
+ */
+static long watchdog_ioctl(struct file *file, unsigned int cmd,
+       unsigned long arg)
+{
+       int status;
+       int new_options;
+       int new_timeout;
+       union {
+               struct watchdog_info __user *ident;
+               int __user *i;
+       } uarg;
+
+       uarg.i = (int __user *)arg;
+
+       switch (cmd) {
+       case WDIOC_GETSUPPORT:
+               return copy_to_user(uarg.ident, &watchdog.ident,
+                       sizeof(watchdog.ident)) ? -EFAULT : 0;
+
+       case WDIOC_GETSTATUS:
+               status = watchdog_get_status();
+               if (status < 0)
+                       return status;
+               return put_user(status, uarg.i);
+
+       case WDIOC_GETBOOTSTATUS:
+               return put_user(0, uarg.i);
+
+       case WDIOC_SETOPTIONS:
+               if (get_user(new_options, uarg.i))
+                       return -EFAULT;
+
+               if (new_options & WDIOS_DISABLECARD)
+                       watchdog_stop();
+
+               if (new_options & WDIOS_ENABLECARD)
+                       return watchdog_start();
+
+
+       case WDIOC_KEEPALIVE:
+               watchdog_keepalive();
+               return 0;
+
+       case WDIOC_SETTIMEOUT:
+               if (get_user(new_timeout, uarg.i))
+                       return -EFAULT;
+
+               if (watchdog_set_timeout(new_timeout))
+                       return -EINVAL;
+
+               watchdog_keepalive();
+               /* Fall */
+
+       case WDIOC_GETTIMEOUT:
+               return put_user(watchdog.timeout, uarg.i);
+
+       default:
+               return -ENOTTY;
+
+       }
+}
+
+static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
+       void *unused)
+{
+       if (code == SYS_DOWN || code == SYS_HALT)
+               watchdog_stop();
+       return NOTIFY_DONE;
+}
+
+static const struct file_operations watchdog_fops = {
+       .owner          = THIS_MODULE,
+       .llseek         = no_llseek,
+       .open           = watchdog_open,
+       .release        = watchdog_release,
+       .write          = watchdog_write,
+       .unlocked_ioctl = watchdog_ioctl,
+};
+
+static struct miscdevice watchdog_miscdev = {
+       .minor          = WATCHDOG_MINOR,
+       .name           = "watchdog",
+       .fops           = &watchdog_fops,
+};
+
+static struct notifier_block watchdog_notifier = {
+       .notifier_call = watchdog_notify_sys,
+};
+
+static int __init watchdog_init(int sioaddr)
+{
+       int wdt_conf, err = 0;
+
+       /* No need to lock watchdog.lock here because no entry points
+        * into the module have been registered yet.
+        */
+       watchdog.sioaddr = sioaddr;
+       watchdog.ident.options = WDIOC_SETTIMEOUT
+                               | WDIOF_MAGICCLOSE
+                               | WDIOF_KEEPALIVEPING;
+
+       snprintf(watchdog.ident.identity,
+               sizeof(watchdog.ident.identity), "%s watchdog",
+               f71808e_names[watchdog.type]);
+
+       err = superio_enter(sioaddr);
+       if (err)
+               return err;
+       superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+       wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
+       watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;
+
+       superio_exit(sioaddr);
+
+       err = watchdog_set_timeout(timeout);
+       if (err)
+               return err;
+       err = watchdog_set_pulse_width(pulse_width);
+       if (err)
+               return err;
+
+       err = register_reboot_notifier(&watchdog_notifier);
+       if (err)
+               return err;
+
+       err = misc_register(&watchdog_miscdev);
+       if (err) {
+               printk(KERN_ERR DRVNAME
+                       ": cannot register miscdev on minor=%d\n",
+                               watchdog_miscdev.minor);
+               goto exit_reboot;
+       }
+
+       if (start_withtimeout) {
+               if (start_withtimeout <= 0
+                || start_withtimeout >  max_timeout) {
+                       printk(KERN_ERR DRVNAME
+                               ": starting timeout out of range\n");
+                       err = -EINVAL;
+                       goto exit_miscdev;
+               }
+
+               err = watchdog_start();
+               if (err) {
+                       printk(KERN_ERR DRVNAME
+                               ": cannot start watchdog timer\n");
+                       goto exit_miscdev;
+               }
+
+               mutex_lock(&watchdog.lock);
+               err = superio_enter(sioaddr);
+               if (err)
+                       goto exit_unlock;
+               superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
+
+               if (start_withtimeout > 0xff) {
+                       /* select minutes for timer units */
+                       superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
+                               F71808FG_FLAG_WD_UNIT);
+                       superio_outb(sioaddr, F71808FG_REG_WD_TIME,
+                               DIV_ROUND_UP(start_withtimeout, 60));
+               } else {
+                       /* select seconds for timer units */
+                       superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
+                               F71808FG_FLAG_WD_UNIT);
+                       superio_outb(sioaddr, F71808FG_REG_WD_TIME,
+                               start_withtimeout);
+               }
+
+               superio_exit(sioaddr);
+               mutex_unlock(&watchdog.lock);
+
+               if (nowayout)
+                       __module_get(THIS_MODULE);
+
+               printk(KERN_INFO DRVNAME
+                       ": watchdog started with initial timeout of %u sec\n",
+                       start_withtimeout);
+       }
+
+       return 0;
+
+exit_unlock:
+       mutex_unlock(&watchdog.lock);
+exit_miscdev:
+       misc_deregister(&watchdog_miscdev);
+exit_reboot:
+       unregister_reboot_notifier(&watchdog_notifier);
+
+       return err;
+}
+
+static int __init f71808e_find(int sioaddr)
+{
+       u16 devid;
+       int err = superio_enter(sioaddr);
+       if (err)
+               return err;
+
+       devid = superio_inw(sioaddr, SIO_REG_MANID);
+       if (devid != SIO_FINTEK_ID) {
+               pr_debug(DRVNAME ": Not a Fintek device\n");
+               err = -ENODEV;
+               goto exit;
+       }
+
+       devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
+       switch (devid) {
+       case SIO_F71808_ID:
+               watchdog.type = f71808fg;
+               break;
+       case SIO_F71882_ID:
+               watchdog.type = f71882fg;
+               break;
+       case SIO_F71862_ID:
+       case SIO_F71889_ID:
+               /* These have a watchdog, though it isn't implemented (yet). */
+               err = -ENOSYS;
+               goto exit;
+       case SIO_F71858_ID:
+               /* Confirmed (by datasheet) not to have a watchdog. */
+               err = -ENODEV;
+               goto exit;
+       default:
+               printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
+                      (unsigned int)devid);
+               err = -ENODEV;
+               goto exit;
+       }
+
+       printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
+               f71808e_names[watchdog.type],
+               (int)superio_inb(sioaddr, SIO_REG_DEVREV));
+exit:
+       superio_exit(sioaddr);
+       return err;
+}
+
+static int __init f71808e_init(void)
+{
+       static const unsigned short addrs[] = { 0x2e, 0x4e };
+       int err = -ENODEV;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(addrs); i++) {
+               err = f71808e_find(addrs[i]);
+               if (err == 0)
+                       break;
+       }
+       if (i == ARRAY_SIZE(addrs))
+               return err;
+
+       return watchdog_init(addrs[i]);
+}
+
+static void __exit f71808e_exit(void)
+{
+       if (watchdog_is_running()) {
+               printk(KERN_WARNING DRVNAME
+                       ": Watchdog timer still running, stopping it\n");
+               watchdog_stop();
+       }
+       misc_deregister(&watchdog_miscdev);
+       unregister_reboot_notifier(&watchdog_notifier);
+}
+
+MODULE_DESCRIPTION("F71808E Watchdog Driver");
+MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
+MODULE_LICENSE("GPL");
+
+module_init(f71808e_init);
+module_exit(f71808e_exit);