[WATCHDOG] w83697hf WDT driver

New watchdog driver for the Winbond W83697HF chipset.
 
Signed-off-by: Marcus Junker <junker@anduras.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 367 insertions, 0 deletions

diff --git a/drivers/char/watchdog/w83697hf_wdt.c b/drivers/char/watchdog/w83697hf_wdt.c
new file mode 100644
index 000000000000..ef6612e1b91f
--- /dev/null
+++ b/drivers/char/watchdog/w83697hf_wdt.c
@@ -0,0 +1,367 @@
+/*
+ *      w83697hf WDT driver
+ *
+ *      (c) Copyright 2006 Marcus Junker <junker@anduras.de>
+ *
+ *      Based on w83627hf_wdt.c advantechwdt.c which is based on wdt.c.
+ *      Original copyright messages:
+ *
+ *     (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
+ *
+ *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ *      (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 Marcus Junker nor ANDURAS AG admit liability nor provide
+ *      warranty for any of this software. This material is provided
+ *      "AS-IS" and at no charge.
+ */
+
+#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 "w83697hf WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
+
+static unsigned long wdt_is_open;
+static char expect_close;
+
+/* You must set this - there is no sane way to probe for this board. */
+static int wdt_io = 0x2E;
+module_param(wdt_io, int, 0);
+MODULE_PARM_DESC(wdt_io, "w83697hf WDT io port (default 0x2E)");
+
+static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ *      Kernel methods.
+ */
+
+#define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
+#define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register (same as EFER) */
+#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
+
+static void
+w83697hf_select_wd_register(void)
+{
+        outb_p(0x87, WDT_EFER); /* Enter extended function mode */
+        outb_p(0x87, WDT_EFER); /* Again according to manual */
+
+        outb_p(0x29, WDT_EFER); /* select CR29 */
+        outb_p(0x20, WDT_EFDR); /* select WDTO */
+
+        outb_p(0x07, WDT_EFER); /* point to logical device number reg */
+        outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
+        outb_p(0x30, WDT_EFER); /* select CR30 */
+        outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
+}
+
+static void
+w83697hf_unselect_wd_register(void)
+{
+        outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
+}
+
+/* tyan motherboards seem to set F5 to 0x4C ?
+ * So explicitly init to appropriate value. */
+static void
+w83697hf_init(void)
+{
+        unsigned char t;
+
+        w83697hf_select_wd_register();
+
+        outb_p(0xF3, WDT_EFER); /* Select CRF3 */
+
+        t=inb_p(WDT_EFDR);      /* read CRF6 */
+        if (t != 0) {
+                printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
+                outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
+        }
+        outb_p(0xF4, WDT_EFER); /* Select CRF4 */
+        t=inb_p(WDT_EFDR);      /* read CRF4 */
+        t&=~0x0C;               /* set second mode & disable keyboard turning off watchdog */
+        outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
+
+        w83697hf_unselect_wd_register();
+}
+
+static void
+wdt_ctrl(int timeout)
+{
+        w83697hf_select_wd_register();
+
+        outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
+        outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
+
+        w83697hf_unselect_wd_register();
+}
+
+static int
+wdt_ping(void)
+{
+        wdt_ctrl(timeout);
+        return 0;
+}
+
+static int
+wdt_disable(void)
+{
+        wdt_ctrl(0);
+        return 0;
+}
+
+static int
+wdt_set_heartbeat(int t)
+{
+        if ((t < 1) || (t > 63))
+                return -EINVAL;
+
+        timeout = t;
+        return 0;
+}
+
+static ssize_t
+wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+        if (count) {
+                if (!nowayout) {
+                        size_t i;
+
+                        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;
+                        }
+                }
+                wdt_ping();
+        }
+        return count;
+}
+
+static int
+wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+          unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        int __user *p = argp;
+        int new_timeout;
+        static struct watchdog_info ident = {
+                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+                .firmware_version = 1,
+                .identity = "W83697HF WDT",
+        };
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+          if (copy_to_user(argp, &ident, sizeof(ident)))
+            return -EFAULT;
+          break;
+
+        case WDIOC_GETSTATUS:
+        case WDIOC_GETBOOTSTATUS:
+          return put_user(0, p);
+
+        case WDIOC_KEEPALIVE:
+          wdt_ping();
+          break;
+
+        case WDIOC_SETTIMEOUT:
+          if (get_user(new_timeout, p))
+                  return -EFAULT;
+          if (wdt_set_heartbeat(new_timeout))
+                  return -EINVAL;
+          wdt_ping();
+          /* Fall */
+
+        case WDIOC_GETTIMEOUT:
+          return put_user(timeout, p);
+
+        case WDIOC_SETOPTIONS:
+        {
+          int options, retval = -EINVAL;
+
+          if (get_user(options, p))
+            return -EFAULT;
+
+          if (options & WDIOS_DISABLECARD) {
+            wdt_disable();
+            retval = 0;
+          }
+
+          if (options & WDIOS_ENABLECARD) {
+            wdt_ping();
+            retval = 0;
+          }
+
+          return retval;
+        }
+
+        default:
+          return -ENOIOCTLCMD;
+        }
+        return 0;
+}
+
+static int
+wdt_open(struct inode *inode, struct file *file)
+{
+        if (test_and_set_bit(0, &wdt_is_open))
+                return -EBUSY;
+        /*
+         *      Activate
+         */
+
+        wdt_ping();
+        return nonseekable_open(inode, file);
+}
+
+static int
+wdt_close(struct inode *inode, struct file *file)
+{
+        if (expect_close == 42) {
+                wdt_disable();
+        } else {
+                printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+                wdt_ping();
+        }
+        expect_close = 0;
+        clear_bit(0, &wdt_is_open);
+        return 0;
+}
+
+/*
+ *      Notifier for system down
+ */
+
+static int
+wdt_notify_sys(struct notifier_block *this, unsigned long code,
+        void *unused)
+{
+        if (code == SYS_DOWN || code == SYS_HALT) {
+                /* Turn the WDT off */
+                wdt_disable();
+        }
+        return NOTIFY_DONE;
+}
+
+/*
+ *      Kernel Interfaces
+ */
+
+static struct file_operations wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = wdt_write,
+        .ioctl          = wdt_ioctl,
+        .open           = wdt_open,
+        .release        = wdt_close,
+};
+
+static struct miscdevice wdt_miscdev = {
+        .minor = WATCHDOG_MINOR,
+        .name = "watchdog",
+        .fops = &wdt_fops,
+};
+
+/*
+ *      The WDT needs to learn about soft shutdowns in order to
+ *      turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+        .notifier_call = wdt_notify_sys,
+};
+
+static int __init
+wdt_init(void)
+{
+        int ret;
+
+        printk(KERN_INFO "WDT driver for the Winbond(TM) W83697HF Super I/O chip initialising.\n");
+
+        if (wdt_set_heartbeat(timeout)) {
+                wdt_set_heartbeat(WATCHDOG_TIMEOUT);
+                printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
+                        WATCHDOG_TIMEOUT);
+        }
+
+        if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
+                printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+                        wdt_io);
+                ret = -EIO;
+                goto out;
+        }
+
+        w83697hf_init();
+
+        ret = register_reboot_notifier(&wdt_notifier);
+        if (ret != 0) {
+                printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+                        ret);
+                goto unreg_regions;
+        }
+
+        ret = misc_register(&wdt_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. timeout=%d sec (nowayout=%d)\n",
+                timeout, nowayout);
+
+out:
+        return ret;
+unreg_reboot:
+        unregister_reboot_notifier(&wdt_notifier);
+unreg_regions:
+        release_region(wdt_io, 1);
+        goto out;
+}
+
+static void __exit
+wdt_exit(void)
+{
+        misc_deregister(&wdt_miscdev);
+        unregister_reboot_notifier(&wdt_notifier);
+        release_region(wdt_io,1);
+}
+
+module_init(wdt_init);
+module_exit(wdt_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marcus Junker <junker@anduras.de>");
+MODULE_DESCRIPTION("w83697hf WDT driver");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);