patch-2.4.3 linux/drivers/char/machzwd.c

• Lines: 546
• Date: Tue Mar 6 19:44:34 2001
• Orig file: v2.4.2/linux/drivers/char/machzwd.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.2/linux/drivers/char/machzwd.c linux/drivers/char/machzwd.c
@@ -0,0 +1,545 @@
+/*
+ *  MachZ ZF-Logic Watchdog Timer driver for Linux
+ *  
+ * 
+ *  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.
+ *
+ *  The author does NOT admit liability nor provide warranty for
+ *  any of this software. This material is provided "AS-IS" in
+ *  the hope that it may be useful for others.
+ *
+ *  Author: Fernando Fuganti <fuganti@conectiva.com.br>
+ *
+ *  Based on sbc60xxwdt.c by Jakob Oestergaard
+ * 
+ *
+ *  We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the 
+ *  following periods:
+ *      wd#1 - 2 seconds;
+ *      wd#2 - 7.2 ms;
+ *  After the expiration of wd#1, it can generate a NMI, SCI, SMI, or 
+ *  a system RESET and it starts wd#2 that unconditionaly will RESET 
+ *  the system when the counter reaches zero.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/malloc.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/smp_lock.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+
+
+/* ports */
+#define ZF_IOBASE	0x218
+#define INDEX		0x218
+#define DATA_B		0x219
+#define DATA_W		0x21A
+#define DATA_D		0x21A
+
+/* indexes */			/* size */
+#define ZFL_VERSION	0x02	/* 16   */
+#define CONTROL 	0x10	/* 16   */	
+#define STATUS		0x12	/* 8    */
+#define COUNTER_1	0x0C	/* 16   */
+#define COUNTER_2	0x0E	/* 8    */
+#define PULSE_LEN	0x0F	/* 8    */
+
+/* controls */
+#define ENABLE_WD1	0x0001
+#define ENABLE_WD2	0x0002
+#define RESET_WD1	0x0010
+#define RESET_WD2	0x0020
+#define GEN_SCI		0x0100
+#define GEN_NMI		0x0200
+#define GEN_SMI		0x0400
+#define GEN_RESET	0x0800
+
+
+/* utilities */
+
+#define WD1	0
+#define WD2	1
+
+#define zf_writew(port, data)  { outb(port, INDEX); outw(data, DATA_W); }
+#define zf_writeb(port, data)  { outb(port, INDEX); outb(data, DATA_B); }
+#define zf_get_ZFL_version()   zf_readw(ZFL_VERSION)
+
+
+static unsigned short zf_readw(unsigned char port)
+{
+	outb(port, INDEX);
+	return inw(DATA_W);
+}
+
+static unsigned short zf_readb(unsigned char port)
+{
+	outb(port, INDEX);
+	return inb(DATA_B);
+}
+
+
+MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
+MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
+MODULE_PARM(action, "i");
+MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*)  1 = SMI  2 = NMI  3 = SCI");
+
+#define PFX "machzwd"
+
+static struct watchdog_info zf_info = {
+	options:		WDIOF_KEEPALIVEPING, 
+	firmware_version:	1, 
+	identity:		"ZF-Logic watchdog"
+};
+
+
+/*
+ * action refers to action taken when watchdog resets
+ * 0 = GEN_RESET
+ * 1 = GEN_SMI
+ * 2 = GEN_NMI
+ * 3 = GEN_SCI
+ * defaults to GEN_RESET (0)
+ */
+static int action = 0;
+static int zf_action = GEN_RESET;
+static int zf_is_open = 0;
+static int zf_expect_close = 0;
+static spinlock_t zf_lock;
+static struct timer_list zf_timer;
+static unsigned long next_heartbeat = 0;
+
+
+/* timeout for user land heart beat (10 seconds) */
+#define ZF_USER_TIMEO (HZ*10)
+
+/* timeout for hardware watchdog (~500ms) */
+#define ZF_HW_TIMEO (HZ/2)
+
+/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
+#define ZF_CTIMEOUT 0xffff
+
+#ifndef ZF_DEBUG
+#	define dprintk(format, args...)
+#else
+#	define dprintk(format, args...) printk(KERN_DEBUG PFX ":" __FUNCTION__ ":%d: " format, __LINE__ , ## args)
+#endif
+
+
+/* STATUS register functions */
+
+static inline unsigned char zf_get_status(void)
+{
+	return zf_readb(STATUS);
+}
+
+static inline void zf_set_status(unsigned char new)
+{
+	zf_writeb(STATUS, new);
+}
+
+
+/* CONTROL register functions */
+
+static inline unsigned short zf_get_control(void)
+{
+	return zf_readw(CONTROL);
+}
+
+static inline void zf_set_control(unsigned short new)
+{
+	zf_writew(CONTROL, new);
+}
+
+
+/* WD#? counter functions */
+/*
+ *	Just get current counter value
+ */
+
+inline unsigned short zf_get_timer(unsigned char n)
+{
+	switch(n){
+		case WD1:
+			return zf_readw(COUNTER_1);
+		case WD2:
+			return zf_readb(COUNTER_2);
+		default:
+			return 0;
+	}
+}
+
+/*
+ *	Just set counter value
+ */
+
+static inline void zf_set_timer(unsigned short new, unsigned char n)
+{
+	switch(n){
+		case WD1:
+			zf_writew(COUNTER_1, new);
+		case WD2:
+			zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
+		default:
+			return;
+	}
+}
+
+/*
+ * stop hardware timer
+ */
+static void zf_timer_off(void)
+{
+	unsigned int ctrl_reg = 0;
+
+	/* stop internal ping */
+	del_timer(&zf_timer);
+
+	/* stop watchdog timer */	
+	ctrl_reg = zf_get_control();
+	ctrl_reg |= (ENABLE_WD1|ENABLE_WD2);	/* disable wd1 and wd2 */
+	ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
+	zf_set_control(ctrl_reg);
+
+	printk(PFX ": Watchdog timer is now disabled\n");
+}
+
+
+/*
+ * start hardware timer 
+ */
+static void zf_timer_on(void)
+{
+	unsigned int ctrl_reg = 0;
+
+	zf_writeb(PULSE_LEN, 0xff);
+
+	zf_set_timer(ZF_CTIMEOUT, WD1);
+
+	/* user land ping */
+	next_heartbeat = jiffies + ZF_USER_TIMEO;
+
+	/* start the timer for internal ping */
+	zf_timer.expires = jiffies + ZF_HW_TIMEO;
+
+	add_timer(&zf_timer);
+
+	/* start watchdog timer */
+	ctrl_reg = zf_get_control();
+	ctrl_reg |= (ENABLE_WD1|zf_action);
+	zf_set_control(ctrl_reg);
+
+	printk(PFX ": Watchdog timer is now enabled\n");
+}
+
+
+static void zf_ping(unsigned long data)
+{
+	unsigned int ctrl_reg = 0;
+
+	zf_writeb(COUNTER_2, 0xff);
+
+	if(time_before(jiffies, next_heartbeat)){
+
+		dprintk("time_before: %ld\n", next_heartbeat - jiffies);
+		
+		/* 
+		 * reset event is activated by transition from 0 to 1 on
+		 * RESET_WD1 bit and we assume that it is already zero...
+		 */
+		ctrl_reg = zf_get_control();    
+		ctrl_reg |= RESET_WD1;		
+		zf_set_control(ctrl_reg);	
+		
+		/* ...and nothing changes until here */
+		ctrl_reg &= ~(RESET_WD1);
+		zf_set_control(ctrl_reg);		
+
+		zf_timer.expires = jiffies + ZF_HW_TIMEO;
+		add_timer(&zf_timer);
+	}else{
+		printk(PFX ": I will reset your machine\n");
+	}
+}
+
+static ssize_t zf_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;
+
+	/* See if we got the magic character */
+	if(count){
+
+/*
+ * no need to check for close confirmation
+ * no way to disable watchdog ;)
+ */
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+		size_t ofs;
+
+		/* 
+		 * note: just in case someone wrote the magic character
+		 * five months ago...
+		 */
+		zf_expect_close = 0;
+
+		/* now scan */
+		for(ofs = 0; ofs != count; ofs++){
+			if(buf[ofs] == 'V'){
+				zf_expect_close = 1;
+				dprintk("zf_expect_close 1\n");
+			}
+		}
+#endif
+		/*
+		 * Well, anyhow someone wrote to us,
+		 * we should return that favour
+		 */
+		next_heartbeat = jiffies + ZF_USER_TIMEO;
+		dprintk("user ping at %ld\n", jiffies);
+		
+		return 1;
+	}
+
+	return 0;
+}
+
+static ssize_t zf_read(struct file *file, char *buf, size_t count, 
+							loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+
+
+static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+	unsigned long arg)
+{
+	int ret;
+		
+	switch(cmd){
+		case WDIOC_GETSUPPORT:
+			ret = copy_to_user((struct watchdog_info *)arg, 
+						&zf_info, sizeof(zf_info));
+			if(ret)
+				return -EFAULT;
+			break;
+	  
+		case WDIOC_GETSTATUS:
+			ret = copy_to_user((int *)arg, &zf_is_open,
+								sizeof(int));
+			if(ret)
+				return -EFAULT;
+			break;
+
+		case WDIOC_KEEPALIVE:
+			zf_ping(0);
+			break;
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static int zf_open(struct inode *inode, struct file *file)
+{
+	switch(MINOR(inode->i_rdev)){
+		case WATCHDOG_MINOR:
+			spin_lock(&zf_lock);
+			if(zf_is_open){
+				spin_unlock(&zf_lock);
+				return -EBUSY;
+			}
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+			MOD_INC_USE_COUNT;
+#endif
+			zf_is_open = 1;
+
+			spin_unlock(&zf_lock);
+
+			zf_timer_on();
+
+			return 0;
+		default:
+			return -ENODEV;
+	}
+}
+
+static int zf_close(struct inode *inode, struct file *file)
+{
+	if(MINOR(inode->i_rdev) == WATCHDOG_MINOR){
+
+		if(zf_expect_close){
+			zf_timer_off();
+		} else {
+			del_timer(&zf_timer);
+			printk(PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
+		}
+		
+		spin_lock(&zf_lock);
+		zf_is_open = 0;
+		spin_unlock(&zf_lock);
+
+		zf_expect_close = 0;
+	}
+	
+	return 0;
+}
+
+/*
+ * Notifier for system down
+ */
+
+static int zf_notify_sys(struct notifier_block *this, unsigned long code,
+								void *unused)
+{
+	if(code == SYS_DOWN || code == SYS_HALT){
+		zf_timer_off();		
+	}
+	
+	return NOTIFY_DONE;
+}
+
+
+
+
+static struct file_operations zf_fops = {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,3,34)
+	owner:          THIS_MODULE,
+#endif
+	read:           zf_read,
+	write:          zf_write,
+	ioctl:          zf_ioctl,
+	open:           zf_open,
+	release:        zf_close,
+};
+
+static struct miscdevice zf_miscdev = {
+	WATCHDOG_MINOR,
+	"watchdog",
+	&zf_fops
+};
+                                                                        
+
+/*
+ * The device needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+static struct notifier_block zf_notifier = {
+	zf_notify_sys,
+	NULL,
+	0
+};
+
+static void __init zf_show_action(int act)
+{
+	char *str[] = { "RESET", "SMI", "NMI", "SCI" };
+	
+	printk(PFX ": Watchdog using action = %s\n", str[act]);
+}
+
+int __init zf_init(void)
+{
+	int ret;
+	
+	printk(PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");
+
+	ret = zf_get_ZFL_version();
+	printk("%#x\n", ret);
+	if((!ret) || (ret != 0xffff)){
+		printk(PFX ": no ZF-Logic found\n");
+		return -ENODEV;
+	}
+
+	if((action <= 3) && (action >= 0)){
+		zf_action = zf_action>>action;
+	} else
+		action = 0;
+	
+	zf_show_action(action);
+
+	spin_lock_init(&zf_lock);
+	
+	ret = misc_register(&zf_miscdev);
+	if (ret){
+		printk(KERN_ERR "can't misc_register on minor=%d\n",
+							WATCHDOG_MINOR);
+		goto out;
+	}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,3)
+	if(check_region(ZF_IOBASE, 3)){
+#else
+	if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){
+#endif
+
+		printk(KERN_ERR "cannot reserve I/O ports at %d\n",
+							ZF_IOBASE);
+		ret = -EBUSY;
+		goto no_region;
+	}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,3)
+	request_region(ZF_IOBASE, 3, "MachZ ZFL WDT");
+#define __exit
+#endif
+
+	ret = register_reboot_notifier(&zf_notifier);
+	if(ret){
+		printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
+									ret);
+		goto no_reboot;
+	}
+	
+	zf_set_status(0);
+	zf_set_control(0);
+
+	/* this is the timer that will do the hard work */
+	init_timer(&zf_timer);
+	zf_timer.function = zf_ping;
+	zf_timer.data = 0;
+	
+	return 0;
+
+no_reboot:
+	release_region(ZF_IOBASE, 3);
+no_region:
+	misc_deregister(&zf_miscdev);
+out:
+	return ret;
+}
+
+	
+void __exit zf_exit(void)
+{
+	zf_timer_off();
+	
+	misc_deregister(&zf_miscdev);
+	unregister_reboot_notifier(&zf_notifier);
+	release_region(ZF_IOBASE, 3);
+}
+
+module_init(zf_init);
+module_exit(zf_exit);