--- /dev/null
+/*
+ * ICP Wafer 5823 Single Board Computer WDT driver
+ * http://www.icpamerica.com/wafer_5823.php
+ * May also work on other similar models
+ *
+ * (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
+ *
+ * Release 0.02
+ *
+ * Based on advantechwdt.c which is based on wdt.c.
+ * Original copyright messages:
+ *
+ * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * 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>
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.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 <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#define WATCHDOG_NAME "Wafer 5823 WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WD_TIMO 60 /* 60 sec default timeout */
+
+static unsigned long wafwdt_is_open;
+static char expect_close;
+static DEFINE_SPINLOCK(wafwdt_lock);
+
+/*
+ * You must set these - there is no sane way to probe for this board.
+ *
+ * To enable, write the timeout value in seconds (1 to 255) to I/O
+ * port WDT_START, then read the port to start the watchdog. To pat
+ * the dog, read port WDT_STOP to stop the timer, then read WDT_START
+ * to restart it again.
+ */
+
+static int wdt_stop = 0x843;
+static int wdt_start = 0x443;
+
+static int timeout = WD_TIMO; /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
+ __MODULE_STRING(WD_TIMO) ".");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void wafwdt_ping(void)
+{
+ /* pat watchdog */
+ spin_lock(&wafwdt_lock);
+ inb_p(wdt_stop);
+ inb_p(wdt_start);
+ spin_unlock(&wafwdt_lock);
+}
+
+static void wafwdt_start(void)
+{
+ /* start up watchdog */
+ outb_p(timeout, wdt_start);
+ inb_p(wdt_start);
+}
+
+static void wafwdt_stop(void)
+{
+ /* stop watchdog */
+ inb_p(wdt_stop);
+}
+
+static ssize_t wafwdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ /* See if we got the magic character 'V' and reload the timer */
+ if (count) {
+ if (!nowayout) {
+ size_t i;
+
+ /* In case it was set long ago */
+ expect_close = 0;
+
+ /* scan to see whether or not we got the magic
+ character */
+ for (i = 0; i != count; i++) {
+ char c;
+ if (get_user(c, buf + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+ /* Well, anyhow someone wrote to us, we should
+ return that favour */
+ wafwdt_ping();
+ }
+ return count;
+}
+
+static long wafwdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int new_timeout;
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 1,
+ .identity = "Wafer 5823 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_SETOPTIONS:
+ {
+ int options, retval = -EINVAL;
+
+ if (get_user(options, p))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD) {
+ wafwdt_stop();
+ retval = 0;
+ }
+
+ if (options & WDIOS_ENABLECARD) {
+ wafwdt_start();
+ retval = 0;
+ }
+
+ return retval;
+ }
+
+ case WDIOC_KEEPALIVE:
+ wafwdt_ping();
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, p))
+ return -EFAULT;
+ if ((new_timeout < 1) || (new_timeout > 255))
+ return -EINVAL;
+ timeout = new_timeout;
+ wafwdt_stop();
+ wafwdt_start();
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static int wafwdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &wafwdt_is_open))
+ return -EBUSY;
+
+ /*
+ * Activate
+ */
+ wafwdt_start();
+ return nonseekable_open(inode, file);
+}
+
+static int wafwdt_close(struct inode *inode, struct file *file)
+{
+ if (expect_close == 42)
+ wafwdt_stop();
+ else {
+ pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
+ wafwdt_ping();
+ }
+ clear_bit(0, &wafwdt_is_open);
+ expect_close = 0;
+ return 0;
+}
+
+/*
+ * Notifier for system down
+ */
+
+static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT)
+ wafwdt_stop();
+ return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static const struct file_operations wafwdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = wafwdt_write,
+ .unlocked_ioctl = wafwdt_ioctl,
+ .open = wafwdt_open,
+ .release = wafwdt_close,
+};
+
+static struct miscdevice wafwdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &wafwdt_fops,
+};
+
+/*
+ * The WDT needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+
+static struct notifier_block wafwdt_notifier = {
+ .notifier_call = wafwdt_notify_sys,
+};
+
+static int __init wafwdt_init(void)
+{
+ int ret;
+
+ pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
+
+ if (timeout < 1 || timeout > 255) {
+ timeout = WD_TIMO;
+ pr_info("timeout value must be 1 <= x <= 255, using %d\n",
+ timeout);
+ }
+
+ if (wdt_stop != wdt_start) {
+ if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
+ pr_err("I/O address 0x%04x already in use\n", wdt_stop);
+ ret = -EIO;
+ goto error;
+ }
+ }
+
+ if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
+ pr_err("I/O address 0x%04x already in use\n", wdt_start);
+ ret = -EIO;
+ goto error2;
+ }
+
+ ret = register_reboot_notifier(&wafwdt_notifier);
+ if (ret != 0) {
+ pr_err("cannot register reboot notifier (err=%d)\n", ret);
+ goto error3;
+ }
+
+ ret = misc_register(&wafwdt_miscdev);
+ if (ret != 0) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto error4;
+ }
+
+ pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
+
+ return ret;
+error4:
+ unregister_reboot_notifier(&wafwdt_notifier);
+error3:
+ release_region(wdt_start, 1);
+error2:
+ if (wdt_stop != wdt_start)
+ release_region(wdt_stop, 1);
+error:
+ return ret;
+}
+
+static void __exit wafwdt_exit(void)
+{
+ misc_deregister(&wafwdt_miscdev);
+ unregister_reboot_notifier(&wafwdt_notifier);
+ if (wdt_stop != wdt_start)
+ release_region(wdt_stop, 1);
+ release_region(wdt_start, 1);
+}
+
+module_init(wafwdt_init);
+module_exit(wafwdt_exit);
+
+MODULE_AUTHOR("Justin Cormack");
+MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
+MODULE_LICENSE("GPL");
+
+/* end of wafer5823wdt.c */
Code Review / kvmfornfv.git / blobdiff