patch-2.4.19 linux-2.4.19/drivers/char/wafer5823wdt.c

• Lines: 221
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/drivers/char/wafer5823wdt.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/drivers/char/wafer5823wdt.c linux-2.4.19/drivers/char/wafer5823wdt.c
@@ -0,0 +1,220 @@
+/*
+ *	ICP Wafer 5823 Single Board Computer WDT driver for Linux 2.4.x
+ *      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@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>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+
+static unsigned long wafwdt_is_open;
+static spinlock_t 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.
+ */
+
+#define WDT_START 0x443
+#define WDT_STOP 0x843
+
+#define WD_TIMO 60		/* 1 minute */
+
+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(WD_TIMO, 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 *buf, size_t count, loff_t * ppos)
+{
+	/*  Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	if (count) {
+		wafwdt_ping();
+		return 1;
+	}
+	return 0;
+}
+
+static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+	     unsigned long arg)
+{
+	static struct watchdog_info ident = {
+		WDIOF_KEEPALIVEPING, 1, "Wafer 5823 WDT"
+	};
+	int one=1;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user
+		    ((struct watchdog_info *) arg, &ident, sizeof (ident)))
+			return -EFAULT;
+		break;
+
+	case WDIOC_GETSTATUS:
+		if (copy_to_user((int *) arg, &one, sizeof (int)))
+			return -EFAULT;
+		break;
+
+	case WDIOC_KEEPALIVE:
+		wafwdt_ping();
+		break;
+
+	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;
+	wafwdt_start();
+	return 0;
+}
+
+static int
+wafwdt_close(struct inode *inode, struct file *file)
+{
+	clear_bit(0, &wafwdt_is_open);
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+        wafwdt_stop();
+#endif
+	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) {
+		/* Turn the WDT off */
+		wafwdt_stop();
+	}
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct file_operations wafwdt_fops = {
+	owner:THIS_MODULE,
+	write:wafwdt_write,
+	ioctl:wafwdt_ioctl,
+	open:wafwdt_open,
+	release:wafwdt_close,
+};
+
+static struct miscdevice wafwdt_miscdev = {
+	WATCHDOG_MINOR,
+	"watchdog",
+	&wafwdt_fops
+};
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off. 
+ */
+
+static struct notifier_block wafwdt_notifier = {
+	wafwdt_notify_sys,
+	NULL,
+	0
+};
+
+static int __init wafwdt_init(void)
+{
+	printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n");
+
+	spin_lock_init(&wafwdt_lock);
+	if(!request_region(WDT_STOP, 1, "Wafer 5823 WDT"))
+		goto error;
+	if(!request_region(WDT_START, 1, "Wafer 5823 WDT"))
+		goto error2;
+	if(misc_register(&wafwdt_miscdev)<0)
+		goto error3;
+	register_reboot_notifier(&wafwdt_notifier);
+	return 0;
+error3:
+	release_region(WDT_START, 1);
+error2:
+	release_region(WDT_STOP, 1);
+error:
+	return -ENODEV;
+}
+
+static void __exit wafwdt_exit(void)
+{
+	misc_deregister(&wafwdt_miscdev);
+	unregister_reboot_notifier(&wafwdt_notifier);
+	release_region(WDT_STOP, 1);
+	release_region(WDT_START, 1);
+}
+
+module_init(wafwdt_init);
+module_exit(wafwdt_exit);
+
+MODULE_AUTHOR("Justin Cormack");
+MODULE_LICENSE("GPL");
+EXPORT_NO_SYMBOLS;
+
+/* end of wafer5823wdt.c */