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path: root/drivers/char/watchdog/wdt977.c
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Diffstat (limited to 'drivers/char/watchdog/wdt977.c')
-rw-r--r--drivers/char/watchdog/wdt977.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/drivers/char/watchdog/wdt977.c b/drivers/char/watchdog/wdt977.c
new file mode 100644
index 000000000000..072e9b214759
--- /dev/null
+++ b/drivers/char/watchdog/wdt977.c
@@ -0,0 +1,459 @@
+/*
+ * Wdt977 0.03: A Watchdog Device for Netwinder W83977AF chip
+ *
+ * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
+ *
+ * -----------------------
+ *
+ * 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.
+ *
+ * -----------------------
+ * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
+ * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
+ * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
+ * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
+ * from minutes to seconds.
+ * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
+ * nwwatchdog_init.
+ */
+
+#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/miscdevice.h>
+#include <linux/init.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/mach-types.h>
+#include <asm/uaccess.h>
+
+#define PFX "Wdt977: "
+#define WATCHDOG_MINOR 130
+
+#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
+
+static int timeout = DEFAULT_TIMEOUT;
+static int timeoutM; /* timeout in minutes */
+static unsigned long timer_alive;
+static int testmode;
+static char expect_close;
+
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+module_param(testmode, int, 0);
+MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
+
+#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)");
+
+/*
+ * Start the watchdog
+ */
+
+static int wdt977_start(void)
+{
+ /* unlock the SuperIO chip */
+ outb(0x87,0x370);
+ outb(0x87,0x370);
+
+ /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
+ * F2 has the timeout in minutes
+ * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
+ * at timeout, and to reset timer on kbd/mouse activity (not impl.)
+ * F4 is used to just clear the TIMEOUT'ed state (bit 0)
+ */
+ outb(0x07,0x370);
+ outb(0x08,0x371);
+ outb(0xF2,0x370);
+ outb(timeoutM,0x371);
+ outb(0xF3,0x370);
+ outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */
+ outb(0xF4,0x370);
+ outb(0x00,0x371);
+
+ /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
+ /* in test mode watch the bit 1 on F4 to indicate "triggered" */
+ if (!testmode)
+ {
+ outb(0x07,0x370);
+ outb(0x07,0x371);
+ outb(0xE6,0x370);
+ outb(0x08,0x371);
+ }
+
+ /* lock the SuperIO chip */
+ outb(0xAA,0x370);
+
+ printk(KERN_INFO PFX "activated.\n");
+
+ return 0;
+}
+
+/*
+ * Stop the watchdog
+ */
+
+static int wdt977_stop(void)
+{
+ /* unlock the SuperIO chip */
+ outb(0x87,0x370);
+ outb(0x87,0x370);
+
+ /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
+ * F3 is reset to its default state
+ * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
+ * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
+ */
+ outb(0x07,0x370);
+ outb(0x08,0x371);
+ outb(0xF2,0x370);
+ outb(0xFF,0x371);
+ outb(0xF3,0x370);
+ outb(0x00,0x371);
+ outb(0xF4,0x370);
+ outb(0x00,0x371);
+ outb(0xF2,0x370);
+ outb(0x00,0x371);
+
+ /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
+ outb(0x07,0x370);
+ outb(0x07,0x371);
+ outb(0xE6,0x370);
+ outb(0x08,0x371);
+
+ /* lock the SuperIO chip */
+ outb(0xAA,0x370);
+
+ printk(KERN_INFO PFX "shutdown.\n");
+
+ return 0;
+}
+
+/*
+ * Send a keepalive ping to the watchdog
+ * This is done by simply re-writing the timeout to reg. 0xF2
+ */
+
+static int wdt977_keepalive(void)
+{
+ /* unlock the SuperIO chip */
+ outb(0x87,0x370);
+ outb(0x87,0x370);
+
+ /* select device Aux2 (device=8) and kicks watchdog reg F2 */
+ /* F2 has the timeout in minutes */
+ outb(0x07,0x370);
+ outb(0x08,0x371);
+ outb(0xF2,0x370);
+ outb(timeoutM,0x371);
+
+ /* lock the SuperIO chip */
+ outb(0xAA,0x370);
+
+ return 0;
+}
+
+/*
+ * Set the watchdog timeout value
+ */
+
+static int wdt977_set_timeout(int t)
+{
+ int tmrval;
+
+ /* convert seconds to minutes, rounding up */
+ tmrval = (t + 59) / 60;
+
+ if (machine_is_netwinder()) {
+ /* we have a hw bug somewhere, so each 977 minute is actually only 30sec
+ * this limits the max timeout to half of device max of 255 minutes...
+ */
+ tmrval += tmrval;
+ }
+
+ if ((tmrval < 1) || (tmrval > 255))
+ return -EINVAL;
+
+ /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */
+ timeout = t;
+ timeoutM = tmrval;
+ return 0;
+}
+
+/*
+ * Get the watchdog status
+ */
+
+static int wdt977_get_status(int *status)
+{
+ int new_status;
+
+ *status=0;
+
+ /* unlock the SuperIO chip */
+ outb(0x87,0x370);
+ outb(0x87,0x370);
+
+ /* select device Aux2 (device=8) and read watchdog reg F4 */
+ outb(0x07,0x370);
+ outb(0x08,0x371);
+ outb(0xF4,0x370);
+ new_status = inb(0x371);
+
+ /* lock the SuperIO chip */
+ outb(0xAA,0x370);
+
+ if (new_status & 1)
+ *status |= WDIOF_CARDRESET;
+
+ return 0;
+}
+
+
+/*
+ * /dev/watchdog handling
+ */
+
+static int wdt977_open(struct inode *inode, struct file *file)
+{
+ /* If the watchdog is alive we don't need to start it again */
+ if( test_and_set_bit(0,&timer_alive) )
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ wdt977_start();
+ return nonseekable_open(inode, file);
+}
+
+static int wdt977_release(struct inode *inode, struct file *file)
+{
+ /*
+ * Shut off the timer.
+ * Lock it in if it's a module and we set nowayout
+ */
+ if (expect_close == 42)
+ {
+ wdt977_stop();
+ clear_bit(0,&timer_alive);
+ } else {
+ printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+ wdt977_keepalive();
+ }
+ expect_close = 0;
+ return 0;
+}
+
+
+/*
+ * wdt977_write:
+ * @file: file handle to the watchdog
+ * @buf: buffer to write (unused as data does not matter here
+ * @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 wdt977_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 */
+ expect_close = 0;
+
+ for (i = 0; i != count; i++) {
+ char c;
+ if (get_user(c, buf + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+
+ wdt977_keepalive();
+ }
+ return count;
+}
+
+/*
+ * wdt977_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 struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .firmware_version = 1,
+ .identity = "Winbond 83977",
+};
+
+static int wdt977_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int status;
+ int new_options, retval = -EINVAL;
+ int new_timeout;
+ union {
+ struct watchdog_info __user *ident;
+ int __user *i;
+ } uarg;
+
+ uarg.i = (int __user *)arg;
+
+ switch(cmd)
+ {
+ default:
+ return -ENOIOCTLCMD;
+
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(uarg.ident, &ident,
+ sizeof(ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ wdt977_get_status(&status);
+ return put_user(status, uarg.i);
+
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, uarg.i);
+
+ case WDIOC_KEEPALIVE:
+ wdt977_keepalive();
+ return 0;
+
+ case WDIOC_SETOPTIONS:
+ if (get_user (new_options, uarg.i))
+ return -EFAULT;
+
+ if (new_options & WDIOS_DISABLECARD) {
+ wdt977_stop();
+ retval = 0;
+ }
+
+ if (new_options & WDIOS_ENABLECARD) {
+ wdt977_start();
+ retval = 0;
+ }
+
+ return retval;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, uarg.i))
+ return -EFAULT;
+
+ if (wdt977_set_timeout(new_timeout))
+ return -EINVAL;
+
+ wdt977_keepalive();
+ /* Fall */
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, uarg.i);
+
+ }
+}
+
+static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if(code==SYS_DOWN || code==SYS_HALT)
+ wdt977_stop();
+ return NOTIFY_DONE;
+}
+
+static struct file_operations wdt977_fops=
+{
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = wdt977_write,
+ .ioctl = wdt977_ioctl,
+ .open = wdt977_open,
+ .release = wdt977_release,
+};
+
+static struct miscdevice wdt977_miscdev=
+{
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &wdt977_fops,
+};
+
+static struct notifier_block wdt977_notifier = {
+ .notifier_call = wdt977_notify_sys,
+};
+
+static int __init nwwatchdog_init(void)
+{
+ int retval;
+ if (!machine_is_netwinder())
+ return -ENODEV;
+
+ /* Check that the timeout value is within it's range ; if not reset to the default */
+ if (wdt977_set_timeout(timeout)) {
+ wdt977_set_timeout(DEFAULT_TIMEOUT);
+ printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n",
+ DEFAULT_TIMEOUT);
+ }
+
+ retval = register_reboot_notifier(&wdt977_notifier);
+ if (retval) {
+ printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+ retval);
+ return retval;
+ }
+
+ retval = misc_register(&wdt977_miscdev);
+ if (retval) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, retval);
+ unregister_reboot_notifier(&wdt977_notifier);
+ return retval;
+ }
+
+ printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode = %i)\n",
+ timeout, nowayout, testmode);
+
+ return 0;
+}
+
+static void __exit nwwatchdog_exit(void)
+{
+ misc_deregister(&wdt977_miscdev);
+ unregister_reboot_notifier(&wdt977_notifier);
+}
+
+module_init(nwwatchdog_init);
+module_exit(nwwatchdog_exit);
+
+MODULE_AUTHOR("Woody Suwalski <woody@netwinder.org>");
+MODULE_DESCRIPTION("W83977AF Watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);