patch-2.3.48 linux/drivers/char/wdt285.c

• Lines: 205
• Date: Thu Feb 24 22:56:47 2000
• Orig file: v2.3.47/linux/drivers/char/wdt285.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.47/linux/drivers/char/wdt285.c linux/drivers/char/wdt285.c
@@ -0,0 +1,204 @@
+/*
+ *	Intel 21285 watchdog driver
+ *	Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
+ *
+ *	based on
+ *
+ *	SoftDog	0.05:	A Software Watchdog Device
+ *
+ *	(c) Copyright 1996 Alan Cox <alan@cymru.net>, All Rights Reserved.
+ *				http://www.cymru.net
+ *
+ *	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.
+ *	
+ */
+ 
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <asm/hardware.h>
+#include <asm/system.h>
+#include <asm/dec21285.h>
+
+/*
+ * Define this to stop the watchdog actually rebooting the machine.
+ */
+#undef ONLY_TESTING
+
+#define TIMER_MARGIN	60		/* (secs) Default is 1 minute */
+
+#define FCLK	(50*1000*1000)		/* 50MHz */
+
+static int soft_margin = TIMER_MARGIN;	/* in seconds */
+static int timer_alive = 0;
+
+#ifdef ONLY_TESTING
+/*
+ *	If the timer expires..
+ */
+
+static void watchdog_fire(int irq, void *dev_id, struct pt_regs *regs)
+{
+	printk(KERN_CRIT "Watchdog: Would Reboot.\n");
+	*CSR_TIMER4_CNTL = 0;
+	*CSR_TIMER4_CLR = 0;
+}
+#endif
+
+static void watchdog_ping(void)
+{
+	/*
+	 *	Refresh the timer.
+	 */
+	*CSR_TIMER4_LOAD = soft_margin * (FCLK / 256);
+}
+
+/*
+ *	Allow only one person to hold it open
+ */
+ 
+static int watchdog_open(struct inode *inode, struct file *file)
+{
+	if(timer_alive)
+		return -EBUSY;
+	MOD_INC_USE_COUNT;
+	/*
+	 *	Ahead watchdog factor ten, Mr Sulu
+	 */
+	*CSR_TIMER4_CLR = 0;
+	watchdog_ping();
+	*CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD 
+		| TIMER_CNTL_DIV256;
+#ifdef ONLY_TESTING
+	request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
+#else
+	*CSR_SA110_CNTL |= 1 << 13;
+#endif
+	timer_alive = 1;
+	return 0;
+}
+
+static int watchdog_release(struct inode *inode, struct file *file)
+{
+#ifdef ONLY_TESTING
+	free_irq(IRQ_TIMER4, NULL);
+	timer_alive = 0;
+	MOD_DEC_USE_COUNT;
+#else
+	/*
+	 *	It's irreversible!
+	 */
+#endif
+	return 0;
+}
+
+static ssize_t watchdog_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+	/*  Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	/*
+	 *	Refresh the timer.
+	 */
+	if(len)
+	{
+		watchdog_ping();
+		return 1;
+	}
+	return 0;
+}
+
+static int watchdog_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	int i;
+	static struct watchdog_info ident=
+	{
+		0,
+		0,
+		"Footbridge Watchdog"
+	};
+	switch(cmd)
+	{
+		default:
+			return -ENOIOCTLCMD;
+		case WDIOC_GETSUPPORT:
+			i = verify_area(VERIFY_WRITE, (void*) arg, sizeof(struct watchdog_info));
+			if (i)
+				return i;
+			else
+				return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident));
+		case WDIOC_GETSTATUS:
+		case WDIOC_GETBOOTSTATUS:
+			return put_user(0,(int *)arg);
+		case WDIOC_KEEPALIVE:
+			watchdog_ping();
+			return 0;
+	}
+}
+
+static struct file_operations watchdog_fops=
+{
+	NULL,		/* Seek */
+	NULL,		/* Read */
+	watchdog_write,	/* Write */
+	NULL,		/* Readdir */
+	NULL,		/* Select */
+	watchdog_ioctl,	/* Ioctl */
+	NULL,		/* MMap */
+	watchdog_open,
+	NULL,		/* flush */
+	watchdog_release,
+	NULL,		
+	NULL		/* Fasync */
+};
+
+static struct miscdevice watchdog_miscdev=
+{
+	WATCHDOG_MINOR,
+	"watchdog",
+	&watchdog_fops
+};
+
+static int __init footbridge_watchdog_init(void)
+{
+	if (machine_is_netwinder())
+		return -ENODEV;
+
+	misc_register(&watchdog_miscdev);
+	printk("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n", 
+	       soft_margin);
+	if (machine_is_cats())
+		printk("Warning: Watchdog reset may not work on this machine.\n");
+	return 0;
+}
+
+static void __exit footbridge_watchdog_exit(void)
+{
+	misc_deregister(&watchdog_miscdev);
+}
+
+EXPORT_NO_SYMBOLS;
+
+MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
+MODULE_DESCRIPTION("21285 watchdog driver");
+
+MODULE_PARM(soft_margin,"i");
+MODULE_PARM_DESC(soft_margin,"Watchdog timeout in seconds");
+
+module_init(footbridge_watchdog_init);
+module_exit(footbridge_watchdog_exit);