1 files changed, 640 insertions, 0 deletions

diff --git a/drivers/watchdog/wdt.c b/drivers/watchdog/wdt.c
new file mode 100644
index 000000000000..0a3de6a02442
--- /dev/null
+++ b/drivers/watchdog/wdt.c
@@ -0,0 +1,640 @@
+/*
+ *      Industrial Computer Source WDT500/501 driver
+ *
+ *      (c) Copyright 1996-1997 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@lxorguk.ukuu.org.uk>
+ *
+ *      Release 0.10.
+ *
+ *      Fixes
+ *              Dave Gregorich  :       Modularisation and minor bugs
+ *              Alan Cox        :       Added the watchdog ioctl() stuff
+ *              Alan Cox        :       Fixed the reboot problem (as noted by
+ *                                      Matt Crocker).
+ *              Alan Cox        :       Added wdt= boot option
+ *              Alan Cox        :       Cleaned up copy/user stuff
+ *              Tim Hockin      :       Added insmod parameters, comment cleanup
+ *                                      Parameterized timeout
+ *              Tigran Aivazian :       Restructured wdt_init() to handle failures
+ *              Joel Becker     :       Added WDIOC_GET/SETTIMEOUT
+ *              Matt Domsch     :       Added nowayout module option
+ */
+
+#include <linux/interrupt.h>
+#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>
+#include "wd501p.h"
+
+static unsigned long wdt_is_open;
+static char expect_close;
+
+/*
+ *      Module parameters
+ */
+
+#define WD_TIMO 60                      /* Default heartbeat = 60 seconds */
+
+static int heartbeat = WD_TIMO;
+static int wd_heartbeat;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/* You must set these - there is no sane way to probe for this board. */
+static int io=0x240;
+static int irq=11;
+
+module_param(io, int, 0);
+MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
+module_param(irq, int, 0);
+MODULE_PARM_DESC(irq, "WDT irq (default=11)");
+
+#ifdef CONFIG_WDT_501
+/* Support for the Fan Tachometer on the WDT501-P */
+static int tachometer;
+
+module_param(tachometer, int, 0);
+MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)");
+#endif /* CONFIG_WDT_501 */
+
+/*
+ *      Programming support
+ */
+
+static void wdt_ctr_mode(int ctr, int mode)
+{
+        ctr<<=6;
+        ctr|=0x30;
+        ctr|=(mode<<1);
+        outb_p(ctr, WDT_CR);
+}
+
+static void wdt_ctr_load(int ctr, int val)
+{
+        outb_p(val&0xFF, WDT_COUNT0+ctr);
+        outb_p(val>>8, WDT_COUNT0+ctr);
+}
+
+/**
+ *      wdt_start:
+ *
+ *      Start the watchdog driver.
+ */
+
+static int wdt_start(void)
+{
+        inb_p(WDT_DC);                  /* Disable watchdog */
+        wdt_ctr_mode(0,3);              /* Program CTR0 for Mode 3: Square Wave Generator */
+        wdt_ctr_mode(1,2);              /* Program CTR1 for Mode 2: Rate Generator */
+        wdt_ctr_mode(2,0);              /* Program CTR2 for Mode 0: Pulse on Terminal Count */
+        wdt_ctr_load(0, 8948);          /* Count at 100Hz */
+        wdt_ctr_load(1,wd_heartbeat);   /* Heartbeat */
+        wdt_ctr_load(2,65535);          /* Length of reset pulse */
+        outb_p(0, WDT_DC);              /* Enable watchdog */
+        return 0;
+}
+
+/**
+ *      wdt_stop:
+ *
+ *      Stop the watchdog driver.
+ */
+
+static int wdt_stop (void)
+{
+        /* Turn the card off */
+        inb_p(WDT_DC);                  /* Disable watchdog */
+        wdt_ctr_load(2,0);              /* 0 length reset pulses now */
+        return 0;
+}
+
+/**
+ *      wdt_ping:
+ *
+ *      Reload counter one with the watchdog heartbeat. We don't bother reloading
+ *      the cascade counter.
+ */
+
+static int wdt_ping(void)
+{
+        /* Write a watchdog value */
+        inb_p(WDT_DC);                  /* Disable watchdog */
+        wdt_ctr_mode(1,2);              /* Re-Program CTR1 for Mode 2: Rate Generator */
+        wdt_ctr_load(1,wd_heartbeat);   /* Heartbeat */
+        outb_p(0, WDT_DC);              /* Enable watchdog */
+        return 0;
+}
+
+/**
+ *      wdt_set_heartbeat:
+ *      @t:             the new heartbeat value that needs to be set.
+ *
+ *      Set a new heartbeat value for the watchdog device. If the heartbeat value is
+ *      incorrect we keep the old value and return -EINVAL. If successfull we
+ *      return 0.
+ */
+static int wdt_set_heartbeat(int t)
+{
+        if ((t < 1) || (t > 65535))
+                return -EINVAL;
+
+        heartbeat = t;
+        wd_heartbeat = t * 100;
+        return 0;
+}
+
+/**
+ *      wdt_get_status:
+ *      @status:                the new status.
+ *
+ *      Extract the status information from a WDT watchdog device. There are
+ *      several board variants so we have to know which bits are valid. Some
+ *      bits default to one and some to zero in order to be maximally painful.
+ *
+ *      we then map the bits onto the status ioctl flags.
+ */
+
+static int wdt_get_status(int *status)
+{
+        unsigned char new_status=inb_p(WDT_SR);
+
+        *status=0;
+        if (new_status & WDC_SR_ISOI0)
+                *status |= WDIOF_EXTERN1;
+        if (new_status & WDC_SR_ISII1)
+                *status |= WDIOF_EXTERN2;
+#ifdef CONFIG_WDT_501
+        if (!(new_status & WDC_SR_TGOOD))
+                *status |= WDIOF_OVERHEAT;
+        if (!(new_status & WDC_SR_PSUOVER))
+                *status |= WDIOF_POWEROVER;
+        if (!(new_status & WDC_SR_PSUUNDR))
+                *status |= WDIOF_POWERUNDER;
+        if (tachometer) {
+                if (!(new_status & WDC_SR_FANGOOD))
+                        *status |= WDIOF_FANFAULT;
+        }
+#endif /* CONFIG_WDT_501 */
+        return 0;
+}
+
+#ifdef CONFIG_WDT_501
+/**
+ *      wdt_get_temperature:
+ *
+ *      Reports the temperature in degrees Fahrenheit. The API is in
+ *      farenheit. It was designed by an imperial measurement luddite.
+ */
+
+static int wdt_get_temperature(int *temperature)
+{
+        unsigned short c=inb_p(WDT_RT);
+
+        *temperature = (c * 11 / 15) + 7;
+        return 0;
+}
+#endif /* CONFIG_WDT_501 */
+
+/**
+ *      wdt_interrupt:
+ *      @irq:           Interrupt number
+ *      @dev_id:        Unused as we don't allow multiple devices.
+ *
+ *      Handle an interrupt from the board. These are raised when the status
+ *      map changes in what the board considers an interesting way. That means
+ *      a failure condition occurring.
+ */
+
+static irqreturn_t wdt_interrupt(int irq, void *dev_id)
+{
+        /*
+         *      Read the status register see what is up and
+         *      then printk it.
+         */
+        unsigned char status=inb_p(WDT_SR);
+
+        printk(KERN_CRIT "WDT status %d\n", status);
+
+#ifdef CONFIG_WDT_501
+        if (!(status & WDC_SR_TGOOD))
+                printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
+        if (!(status & WDC_SR_PSUOVER))
+                printk(KERN_CRIT "PSU over voltage.\n");
+        if (!(status & WDC_SR_PSUUNDR))
+                printk(KERN_CRIT "PSU under voltage.\n");
+        if (tachometer) {
+                if (!(status & WDC_SR_FANGOOD))
+                        printk(KERN_CRIT "Possible fan fault.\n");
+        }
+#endif /* CONFIG_WDT_501 */
+        if (!(status & WDC_SR_WCCR))
+#ifdef SOFTWARE_REBOOT
+#ifdef ONLY_TESTING
+                printk(KERN_CRIT "Would Reboot.\n");
+#else
+                printk(KERN_CRIT "Initiating system reboot.\n");
+                emergency_restart();
+#endif
+#else
+                printk(KERN_CRIT "Reset in 5ms.\n");
+#endif
+        return IRQ_HANDLED;
+}
+
+
+/**
+ *      wdt_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 wdt_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;
+                        }
+                }
+                wdt_ping();
+        }
+        return count;
+}
+
+/**
+ *      wdt_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. We only actually usefully support
+ *      querying capabilities and current status.
+ */
+
+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_heartbeat;
+        int status;
+
+        static struct watchdog_info ident = {
+                .options =              WDIOF_SETTIMEOUT|
+                                        WDIOF_MAGICCLOSE|
+                                        WDIOF_KEEPALIVEPING,
+                .firmware_version =     1,
+                .identity =             "WDT500/501",
+        };
+
+        /* Add options according to the card we have */
+        ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
+#ifdef CONFIG_WDT_501
+        ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
+        if (tachometer)
+                ident.options |= WDIOF_FANFAULT;
+#endif /* CONFIG_WDT_501 */
+
+        switch(cmd)
+        {
+                default:
+                        return -ENOTTY;
+                case WDIOC_GETSUPPORT:
+                        return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
+
+                case WDIOC_GETSTATUS:
+                        wdt_get_status(&status);
+                        return put_user(status, p);
+                case WDIOC_GETBOOTSTATUS:
+                        return put_user(0, p);
+                case WDIOC_KEEPALIVE:
+                        wdt_ping();
+                        return 0;
+                case WDIOC_SETTIMEOUT:
+                        if (get_user(new_heartbeat, p))
+                                return -EFAULT;
+
+                        if (wdt_set_heartbeat(new_heartbeat))
+                                return -EINVAL;
+
+                        wdt_ping();
+                        /* Fall */
+                case WDIOC_GETTIMEOUT:
+                        return put_user(heartbeat, p);
+        }
+}
+
+/**
+ *      wdt_open:
+ *      @inode: inode of device
+ *      @file: file handle to device
+ *
+ *      The watchdog device has been opened. The watchdog device is single
+ *      open and on opening we load the counters. Counter zero is a 100Hz
+ *      cascade, into counter 1 which downcounts to reboot. When the counter
+ *      triggers counter 2 downcounts the length of the reset pulse which
+ *      set set to be as long as possible.
+ */
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+        if(test_and_set_bit(0, &wdt_is_open))
+                return -EBUSY;
+        /*
+         *      Activate
+         */
+        wdt_start();
+        return nonseekable_open(inode, file);
+}
+
+/**
+ *      wdt_release:
+ *      @inode: inode to board
+ *      @file: file handle to board
+ *
+ *      The watchdog has a configurable API. There is a religious dispute
+ *      between people who want their watchdog to be able to shut down and
+ *      those who want to be sure if the watchdog manager dies the machine
+ *      reboots. In the former case we disable the counters, in the latter
+ *      case you have to open it again very soon.
+ */
+
+static int wdt_release(struct inode *inode, struct file *file)
+{
+        if (expect_close == 42) {
+                wdt_stop();
+                clear_bit(0, &wdt_is_open);
+        } else {
+                printk(KERN_CRIT "wdt: WDT device closed unexpectedly.  WDT will not stop!\n");
+                wdt_ping();
+        }
+        expect_close = 0;
+        return 0;
+}
+
+#ifdef CONFIG_WDT_501
+/**
+ *      wdt_temp_read:
+ *      @file: file handle to the watchdog board
+ *      @buf: buffer to write 1 byte into
+ *      @count: length of buffer
+ *      @ptr: offset (no seek allowed)
+ *
+ *      Temp_read reports the temperature in degrees Fahrenheit. The API is in
+ *      farenheit. It was designed by an imperial measurement luddite.
+ */
+
+static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
+{
+        int temperature;
+
+        if (wdt_get_temperature(&temperature))
+                return -EFAULT;
+
+        if (copy_to_user (buf, &temperature, 1))
+                return -EFAULT;
+
+        return 1;
+}
+
+/**
+ *      wdt_temp_open:
+ *      @inode: inode of device
+ *      @file: file handle to device
+ *
+ *      The temperature device has been opened.
+ */
+
+static int wdt_temp_open(struct inode *inode, struct file *file)
+{
+        return nonseekable_open(inode, file);
+}
+
+/**
+ *      wdt_temp_release:
+ *      @inode: inode to board
+ *      @file: file handle to board
+ *
+ *      The temperature device has been closed.
+ */
+
+static int wdt_temp_release(struct inode *inode, struct file *file)
+{
+        return 0;
+}
+#endif /* CONFIG_WDT_501 */
+
+/**
+ *      notify_sys:
+ *      @this: our notifier block
+ *      @code: the event being reported
+ *      @unused: unused
+ *
+ *      Our notifier is called on system shutdowns. We want to turn the card
+ *      off at reboot otherwise the machine will reboot again during memory
+ *      test or worse yet during the following fsck. This would suck, in fact
+ *      trust me - if it happens it does suck.
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+        void *unused)
+{
+        if(code==SYS_DOWN || code==SYS_HALT) {
+                /* Turn the card off */
+                wdt_stop();
+        }
+        return NOTIFY_DONE;
+}
+
+/*
+ *      Kernel Interfaces
+ */
+
+
+static const struct file_operations wdt_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = wdt_write,
+        .ioctl          = wdt_ioctl,
+        .open           = wdt_open,
+        .release        = wdt_release,
+};
+
+static struct miscdevice wdt_miscdev = {
+        .minor  = WATCHDOG_MINOR,
+        .name   = "watchdog",
+        .fops   = &wdt_fops,
+};
+
+#ifdef CONFIG_WDT_501
+static const struct file_operations wdt_temp_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .read           = wdt_temp_read,
+        .open           = wdt_temp_open,
+        .release        = wdt_temp_release,
+};
+
+static struct miscdevice temp_miscdev = {
+        .minor  = TEMP_MINOR,
+        .name   = "temperature",
+        .fops   = &wdt_temp_fops,
+};
+#endif /* CONFIG_WDT_501 */
+
+/*
+ *      The WDT card 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,
+};
+
+/**
+ *      cleanup_module:
+ *
+ *      Unload the watchdog. You cannot do this with any file handles open.
+ *      If your watchdog is set to continue ticking on close and you unload
+ *      it, well it keeps ticking. We won't get the interrupt but the board
+ *      will not touch PC memory so all is fine. You just have to load a new
+ *      module in 60 seconds or reboot.
+ */
+
+static void __exit wdt_exit(void)
+{
+        misc_deregister(&wdt_miscdev);
+#ifdef CONFIG_WDT_501
+        misc_deregister(&temp_miscdev);
+#endif /* CONFIG_WDT_501 */
+        unregister_reboot_notifier(&wdt_notifier);
+        free_irq(irq, NULL);
+        release_region(io,8);
+}
+
+/**
+ *      wdt_init:
+ *
+ *      Set up the WDT watchdog board. All we have to do is grab the
+ *      resources we require and bitch if anyone beat us to them.
+ *      The open() function will actually kick the board off.
+ */
+
+static int __init wdt_init(void)
+{
+        int ret;
+
+        /* Check that the heartbeat value is within it's range ; if not reset to the default */
+        if (wdt_set_heartbeat(heartbeat)) {
+                wdt_set_heartbeat(WD_TIMO);
+                printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n",
+                        WD_TIMO);
+        }
+
+        if (!request_region(io, 8, "wdt501p")) {
+                printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io);
+                ret = -EBUSY;
+                goto out;
+        }
+
+        ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL);
+        if(ret) {
+                printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
+                goto outreg;
+        }
+
+        ret = register_reboot_notifier(&wdt_notifier);
+        if(ret) {
+                printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret);
+                goto outirq;
+        }
+
+#ifdef CONFIG_WDT_501
+        ret = misc_register(&temp_miscdev);
+        if (ret) {
+                printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
+                        TEMP_MINOR, ret);
+                goto outrbt;
+        }
+#endif /* CONFIG_WDT_501 */
+
+        ret = misc_register(&wdt_miscdev);
+        if (ret) {
+                printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
+                        WATCHDOG_MINOR, ret);
+                goto outmisc;
+        }
+
+        ret = 0;
+        printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
+                io, irq, heartbeat, nowayout);
+#ifdef CONFIG_WDT_501
+        printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
+#endif /* CONFIG_WDT_501 */
+
+out:
+        return ret;
+
+outmisc:
+#ifdef CONFIG_WDT_501
+        misc_deregister(&temp_miscdev);
+outrbt:
+#endif /* CONFIG_WDT_501 */
+        unregister_reboot_notifier(&wdt_notifier);
+outirq:
+        free_irq(irq, NULL);
+outreg:
+        release_region(io,8);
+        goto out;
+}
+
+module_init(wdt_init);
+module_exit(wdt_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS_MISCDEV(TEMP_MINOR);
+MODULE_LICENSE("GPL");