1 files changed, 352 insertions, 0 deletions

diff --git a/drivers/char/watchdog/ib700wdt.c b/drivers/char/watchdog/ib700wdt.c
new file mode 100644
index 000000000000..d974f16e84d2
--- /dev/null
+++ b/drivers/char/watchdog/ib700wdt.c
@@ -0,0 +1,352 @@
+/*
+ *      IB700 Single Board Computer WDT driver
+ *
+ *      (c) Copyright 2001 Charles Howes <chowes@vsol.net>
+ *
+ *      Based on advantechwdt.c which is based on acquirewdt.c which
+ *       is based on wdt.c.
+ *
+ *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ *      Based on acquirewdt.c which is 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
+ *           Added timeout module option to override default
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+static unsigned long ibwdt_is_open;
+static spinlock_t ibwdt_lock;
+static char expect_close;
+
+#define PFX "ib700wdt: "
+
+/*
+ *
+ * Watchdog Timer Configuration
+ *
+ * The function of the watchdog timer is to reset the system
+ * automatically and is defined at I/O port 0443H.  To enable the
+ * watchdog timer and allow the system to reset, write I/O port 0443H.
+ * To disable the timer, write I/O port 0441H for the system to stop the
+ * watchdog function.  The timer has a tolerance of 20% for its
+ * intervals.
+ *
+ * The following describes how the timer should be programmed.
+ *
+ * Enabling Watchdog:
+ * MOV AX,000FH (Choose the values from 0 to F)
+ * MOV DX,0443H
+ * OUT DX,AX
+ *
+ * Disabling Watchdog:
+ * MOV AX,000FH (Any value is fine.)
+ * MOV DX,0441H
+ * OUT DX,AX
+ *
+ * Watchdog timer control table:
+ * Level   Value  Time/sec | Level Value Time/sec
+ *   1       F       0     |   9     7      16
+ *   2       E       2     |   10    6      18
+ *   3       D       4     |   11    5      20
+ *   4       C       6     |   12    4      22
+ *   5       B       8     |   13    3      24
+ *   6       A       10    |   14    2      26
+ *   7       9       12    |   15    1      28
+ *   8       8       14    |   16    0      30
+ *
+ */
+
+static int wd_times[] = {
+        30,     /* 0x0 */
+        28,     /* 0x1 */
+        26,     /* 0x2 */
+        24,     /* 0x3 */
+        22,     /* 0x4 */
+        20,     /* 0x5 */
+        18,     /* 0x6 */
+        16,     /* 0x7 */
+        14,     /* 0x8 */
+        12,     /* 0x9 */
+        10,     /* 0xA */
+        8,      /* 0xB */
+        6,      /* 0xC */
+        4,      /* 0xD */
+        2,      /* 0xE */
+        0,      /* 0xF */
+};
+
+#define WDT_STOP 0x441
+#define WDT_START 0x443
+
+/* Default timeout */
+#define WD_TIMO 0               /* 30 seconds +/- 20%, from table */
+
+static int wd_margin = WD_TIMO;
+
+#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
+ibwdt_ping(void)
+{
+        /* Write a watchdog value */
+        outb_p(wd_margin, WDT_START);
+}
+
+static ssize_t
+ibwdt_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;
+                        }
+                }
+                ibwdt_ping();
+        }
+        return count;
+}
+
+static int
+ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+          unsigned long arg)
+{
+        int i, new_margin;
+        void __user *argp = (void __user *)arg;
+        int __user *p = argp;
+
+        static struct watchdog_info ident = {
+                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+                .firmware_version = 1,
+                .identity = "IB700 WDT",
+        };
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+          if (copy_to_user(argp, &ident, sizeof(ident)))
+            return -EFAULT;
+          break;
+
+        case WDIOC_GETSTATUS:
+          return put_user(0, p);
+
+        case WDIOC_KEEPALIVE:
+          ibwdt_ping();
+          break;
+
+        case WDIOC_SETTIMEOUT:
+          if (get_user(new_margin, p))
+                  return -EFAULT;
+          if ((new_margin < 0) || (new_margin > 30))
+                  return -EINVAL;
+          for (i = 0x0F; i > -1; i--)
+                  if (wd_times[i] > new_margin)
+                          break;
+          wd_margin = i;
+          ibwdt_ping();
+          /* Fall */
+
+        case WDIOC_GETTIMEOUT:
+          return put_user(wd_times[wd_margin], p);
+          break;
+
+        default:
+          return -ENOIOCTLCMD;
+        }
+        return 0;
+}
+
+static int
+ibwdt_open(struct inode *inode, struct file *file)
+{
+        spin_lock(&ibwdt_lock);
+        if (test_and_set_bit(0, &ibwdt_is_open)) {
+                spin_unlock(&ibwdt_lock);
+                return -EBUSY;
+        }
+        if (nowayout)
+                __module_get(THIS_MODULE);
+
+        /* Activate */
+        ibwdt_ping();
+        spin_unlock(&ibwdt_lock);
+        return nonseekable_open(inode, file);
+}
+
+static int
+ibwdt_close(struct inode *inode, struct file *file)
+{
+        spin_lock(&ibwdt_lock);
+        if (expect_close == 42)
+                outb_p(0, WDT_STOP);
+        else
+                printk(KERN_CRIT PFX "WDT device closed unexpectedly.  WDT will not stop!\n");
+
+        clear_bit(0, &ibwdt_is_open);
+        expect_close = 0;
+        spin_unlock(&ibwdt_lock);
+        return 0;
+}
+
+/*
+ *      Notifier for system down
+ */
+
+static int
+ibwdt_notify_sys(struct notifier_block *this, unsigned long code,
+        void *unused)
+{
+        if (code == SYS_DOWN || code == SYS_HALT) {
+                /* Turn the WDT off */
+                outb_p(0, WDT_STOP);
+        }
+        return NOTIFY_DONE;
+}
+
+/*
+ *      Kernel Interfaces
+ */
+
+static struct file_operations ibwdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = ibwdt_write,
+        .ioctl          = ibwdt_ioctl,
+        .open           = ibwdt_open,
+        .release        = ibwdt_close,
+};
+
+static struct miscdevice ibwdt_miscdev = {
+        .minor = WATCHDOG_MINOR,
+        .name = "watchdog",
+        .fops = &ibwdt_fops,
+};
+
+/*
+ *      The WDT needs to learn about soft shutdowns in order to
+ *      turn the timebomb registers off.
+ */
+
+static struct notifier_block ibwdt_notifier = {
+        .notifier_call = ibwdt_notify_sys,
+};
+
+static int __init ibwdt_init(void)
+{
+        int res;
+
+        printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n");
+
+        spin_lock_init(&ibwdt_lock);
+        res = misc_register(&ibwdt_miscdev);
+        if (res) {
+                printk (KERN_ERR PFX "failed to register misc device\n");
+                goto out_nomisc;
+        }
+
+#if WDT_START != WDT_STOP
+        if (!request_region(WDT_STOP, 1, "IB700 WDT")) {
+                printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP);
+                res = -EIO;
+                goto out_nostopreg;
+        }
+#endif
+
+        if (!request_region(WDT_START, 1, "IB700 WDT")) {
+                printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START);
+                res = -EIO;
+                goto out_nostartreg;
+        }
+        res = register_reboot_notifier(&ibwdt_notifier);
+        if (res) {
+                printk (KERN_ERR PFX "Failed to register reboot notifier.\n");
+                goto out_noreboot;
+        }
+        return 0;
+
+out_noreboot:
+        release_region(WDT_START, 1);
+out_nostartreg:
+#if WDT_START != WDT_STOP
+        release_region(WDT_STOP, 1);
+#endif
+out_nostopreg:
+        misc_deregister(&ibwdt_miscdev);
+out_nomisc:
+        return res;
+}
+
+static void __exit
+ibwdt_exit(void)
+{
+        misc_deregister(&ibwdt_miscdev);
+        unregister_reboot_notifier(&ibwdt_notifier);
+#if WDT_START != WDT_STOP
+        release_region(WDT_STOP,1);
+#endif
+        release_region(WDT_START,1);
+}
+
+module_init(ibwdt_init);
+module_exit(ibwdt_exit);
+
+MODULE_AUTHOR("Charles Howes <chowes@vsol.net>");
+MODULE_DESCRIPTION("IB700 SBC watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+
+/* end of ib700wdt.c */