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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [watchdog/] [machzwd.c] - Blame information for rev 62

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/*
 *  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.
 *
 *  14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *      Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 */
 
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/jiffies.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>
 
/* 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);
}
 
 
MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 
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) ")");
 
#define PFX "machzwd"
 
static struct watchdog_info zf_info = {
        .options                = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
        .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;
module_param(action, int, 0);
MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*)  1 = SMI  2 = NMI  3 = SCI");
 
static void zf_ping(unsigned long data);
 
static int zf_action = GEN_RESET;
static unsigned long zf_is_open;
static char zf_expect_close;
static DEFINE_SPINLOCK(zf_lock);
static DEFINE_SPINLOCK(zf_port_lock);
static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);
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 ":%s:%d: " format, __FUNCTION__, __LINE__ , ## args)
#endif
 
 
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 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;
        unsigned long flags;
 
        /* stop internal ping */
        del_timer_sync(&zf_timer);
 
        spin_lock_irqsave(&zf_port_lock, flags);
        /* 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);
        spin_unlock_irqrestore(&zf_port_lock, flags);
 
        printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");
}
 
 
/*
 * start hardware timer
 */
static void zf_timer_on(void)
{
        unsigned int ctrl_reg = 0;
        unsigned long flags;
 
        spin_lock_irqsave(&zf_port_lock, flags);
 
        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 */
        mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
 
        /* start watchdog timer */
        ctrl_reg = zf_get_control();
        ctrl_reg |= (ENABLE_WD1|zf_action);
        zf_set_control(ctrl_reg);
        spin_unlock_irqrestore(&zf_port_lock, flags);
 
        printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");
}
 
 
static void zf_ping(unsigned long data)
{
        unsigned int ctrl_reg = 0;
        unsigned long flags;
 
        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...
                 */
 
                spin_lock_irqsave(&zf_port_lock, flags);
                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);
                spin_unlock_irqrestore(&zf_port_lock, flags);
 
                mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
        }else{
                printk(KERN_CRIT PFX ": I will reset your machine\n");
        }
}
 
static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
                                                                loff_t *ppos)
{
        /* See if we got the magic character */
        if(count){
 
                /*
                 * no need to check for close confirmation
                 * no way to disable watchdog ;)
                 */
                if (!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++){
                                char c;
                                if (get_user(c, buf + ofs))
                                        return -EFAULT;
                                if (c == 'V'){
                                        zf_expect_close = 42;
                                        dprintk("zf_expect_close = 42\n");
                                }
                        }
                }
 
                /*
                 * 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 count;
}
 
static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
        unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
        switch (cmd) {
        case WDIOC_GETSUPPORT:
                if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
                        return -EFAULT;
                break;
 
        case WDIOC_GETSTATUS:
        case WDIOC_GETBOOTSTATUS:
                return put_user(0, p);
 
        case WDIOC_KEEPALIVE:
                zf_ping(0);
                break;
 
        default:
                return -ENOTTY;
        }
 
        return 0;
}
 
static int zf_open(struct inode *inode, struct file *file)
{
        spin_lock(&zf_lock);
        if(test_and_set_bit(0, &zf_is_open)) {
                spin_unlock(&zf_lock);
                return -EBUSY;
        }
 
        if (nowayout)
                __module_get(THIS_MODULE);
 
        spin_unlock(&zf_lock);
 
        zf_timer_on();
 
        return nonseekable_open(inode, file);
}
 
static int zf_close(struct inode *inode, struct file *file)
{
        if(zf_expect_close == 42){
                zf_timer_off();
        } else {
                del_timer(&zf_timer);
                printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");
        }
 
        spin_lock(&zf_lock);
        clear_bit(0, &zf_is_open);
        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 const struct file_operations zf_fops = {
        .owner          = THIS_MODULE,
        .llseek         = no_llseek,
        .write          = zf_write,
        .ioctl          = zf_ioctl,
        .open           = zf_open,
        .release        = zf_close,
};
 
static struct miscdevice zf_miscdev = {
        .minor = WATCHDOG_MINOR,
        .name = "watchdog",
        .fops = &zf_fops,
};
 
 
/*
 * The device needs to learn about soft shutdowns in order to
 * turn the timebomb registers off.
 */
static struct notifier_block zf_notifier = {
        .notifier_call = zf_notify_sys,
};
 
static void __init zf_show_action(int act)
{
        char *str[] = { "RESET", "SMI", "NMI", "SCI" };
 
        printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);
}
 
static int __init zf_init(void)
{
        int ret;
 
        printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");
 
        ret = zf_get_ZFL_version();
        if ((!ret) || (ret == 0xffff)) {
                printk(KERN_WARNING 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);
 
        if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){
                printk(KERN_ERR "cannot reserve I/O ports at %d\n",
                                                        ZF_IOBASE);
                ret = -EBUSY;
                goto no_region;
        }
 
        ret = register_reboot_notifier(&zf_notifier);
        if(ret){
                printk(KERN_ERR "can't register reboot notifier (err=%d)\n",
                                                                        ret);
                goto no_reboot;
        }
 
        ret = misc_register(&zf_miscdev);
        if (ret){
                printk(KERN_ERR "can't misc_register on minor=%d\n",
                                                        WATCHDOG_MINOR);
                goto no_misc;
        }
 
        zf_set_status(0);
        zf_set_control(0);
 
        return 0;
 
no_misc:
        unregister_reboot_notifier(&zf_notifier);
no_reboot:
        release_region(ZF_IOBASE, 3);
no_region:
        return ret;
}
 
 
static 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);

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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [watchdog/] [machzwd.c] - Blame information for rev 62

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* MachZ ZF-Logic Watchdog Timer driver for Linux`
3			`*`
4			`*`
5			`* This program is free software; you can redistribute it and/or`
6			`* modify it under the terms of the GNU General Public License`
7			`* as published by the Free Software Foundation; either version`
8			`* 2 of the License, or (at your option) any later version.`
9			`*`
10			`* The author does NOT admit liability nor provide warranty for`
11			`* any of this software. This material is provided "AS-IS" in`
12			`* the hope that it may be useful for others.`
13			`*`
14			`* Author: Fernando Fuganti <fuganti@conectiva.com.br>`
15			`*`
16			`* Based on sbc60xxwdt.c by Jakob Oestergaard`
17			`*`
18			`*`
19			`* We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the`
20			`* following periods:`
21			`* wd#1 - 2 seconds;`
22			`* wd#2 - 7.2 ms;`
23			`* After the expiration of wd#1, it can generate a NMI, SCI, SMI, or`
24			`* a system RESET and it starts wd#2 that unconditionaly will RESET`
25			`* the system when the counter reaches zero.`
26			`*`
27			`* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>`
28			`* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT`
29			`*/`
30
31			`#include <linux/module.h>`
32			`#include <linux/moduleparam.h>`
33			`#include <linux/types.h>`
34			`#include <linux/timer.h>`
35			`#include <linux/jiffies.h>`
36			`#include <linux/miscdevice.h>`
37			`#include <linux/watchdog.h>`
38			`#include <linux/fs.h>`
39			`#include <linux/ioport.h>`
40			`#include <linux/notifier.h>`
41			`#include <linux/reboot.h>`
42			`#include <linux/init.h>`
43
44			`#include <asm/io.h>`
45			`#include <asm/uaccess.h>`
46			`#include <asm/system.h>`
47
48			`/* ports */`
49			`#define ZF_IOBASE 0x218`
50			`#define INDEX 0x218`
51			`#define DATA_B 0x219`
52			`#define DATA_W 0x21A`
53			`#define DATA_D 0x21A`
54
55			`/* indexes / / size */`
56			`#define ZFL_VERSION 0x02 /* 16 */`
57			`#define CONTROL 0x10 /* 16 */`
58			`#define STATUS 0x12 /* 8 */`
59			`#define COUNTER_1 0x0C /* 16 */`
60			`#define COUNTER_2 0x0E /* 8 */`
61			`#define PULSE_LEN 0x0F /* 8 */`
62
63			`/* controls */`
64			`#define ENABLE_WD1 0x0001`
65			`#define ENABLE_WD2 0x0002`
66			`#define RESET_WD1 0x0010`
67			`#define RESET_WD2 0x0020`
68			`#define GEN_SCI 0x0100`
69			`#define GEN_NMI 0x0200`
70			`#define GEN_SMI 0x0400`
71			`#define GEN_RESET 0x0800`
72
73
74			`/* utilities */`
75
76			`#define WD1 0`
77			`#define WD2 1`
78
79			`#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }`
80			`#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }`
81			`#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)`
82
83
84			`static unsigned short zf_readw(unsigned char port)`
85			`{`
86			`outb(port, INDEX);`
87			`return inw(DATA_W);`
88			`}`
89
90
91			`MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");`
92			`MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");`
93			`MODULE_LICENSE("GPL");`
94			`MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);`
95
96			`static int nowayout = WATCHDOG_NOWAYOUT;`
97			`module_param(nowayout, int, 0);`
98			`MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");`
99
100			`#define PFX "machzwd"`
101
102			`static struct watchdog_info zf_info = {`
103			`.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,`
104			`.firmware_version = 1,`
105			`.identity = "ZF-Logic watchdog",`
106			`};`
107
108
109			`/*`
110			`* action refers to action taken when watchdog resets`
111			`* 0 = GEN_RESET`
112			`* 1 = GEN_SMI`
113			`* 2 = GEN_NMI`
114			`* 3 = GEN_SCI`
115			`* defaults to GEN_RESET (0)`
116			`*/`
117			`static int action = 0;`
118			`module_param(action, int, 0);`
119			`MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");`
120
121			`static void zf_ping(unsigned long data);`
122
123			`static int zf_action = GEN_RESET;`
124			`static unsigned long zf_is_open;`
125			`static char zf_expect_close;`
126			`static DEFINE_SPINLOCK(zf_lock);`
127			`static DEFINE_SPINLOCK(zf_port_lock);`
128			`static DEFINE_TIMER(zf_timer, zf_ping, 0, 0);`
129			`static unsigned long next_heartbeat = 0;`
130
131
132			`/* timeout for user land heart beat (10 seconds) */`
133			`#define ZF_USER_TIMEO (HZ*10)`
134
135			`/* timeout for hardware watchdog (~500ms) */`
136			`#define ZF_HW_TIMEO (HZ/2)`
137
138			`/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */`
139			`#define ZF_CTIMEOUT 0xffff`
140
141			`#ifndef ZF_DEBUG`
142			`# define dprintk(format, args...)`
143			`#else`
144			`# define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __FUNCTION__, __LINE__ , ## args)`
145			`#endif`
146
147
148			`static inline void zf_set_status(unsigned char new)`
149			`{`
150			`zf_writeb(STATUS, new);`
151			`}`
152
153
154			`/* CONTROL register functions */`
155
156			`static inline unsigned short zf_get_control(void)`
157			`{`
158			`return zf_readw(CONTROL);`
159			`}`
160
161			`static inline void zf_set_control(unsigned short new)`
162			`{`
163			`zf_writew(CONTROL, new);`
164			`}`
165
166
167			`/* WD#? counter functions */`
168			`/*`
169			`* Just set counter value`
170			`*/`
171
172			`static inline void zf_set_timer(unsigned short new, unsigned char n)`
173			`{`
174			`switch(n){`
175			`case WD1:`
176			`zf_writew(COUNTER_1, new);`
177			`case WD2:`
178			`zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);`
179			`default:`
180			`return;`
181			`}`
182			`}`
183
184			`/*`
185			`* stop hardware timer`
186			`*/`
187			`static void zf_timer_off(void)`
188			`{`
189			`unsigned int ctrl_reg = 0;`
190			`unsigned long flags;`
191
192			`/* stop internal ping */`
193			`del_timer_sync(&zf_timer);`
194
195			`spin_lock_irqsave(&zf_port_lock, flags);`
196			`/* stop watchdog timer */`
197			`ctrl_reg = zf_get_control();`
198			`ctrl_reg \|= (ENABLE_WD1\|ENABLE_WD2); /* disable wd1 and wd2 */`
199			`ctrl_reg &= ~(ENABLE_WD1\|ENABLE_WD2);`
200			`zf_set_control(ctrl_reg);`
201			`spin_unlock_irqrestore(&zf_port_lock, flags);`
202
203			`printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");`
204			`}`
205
206
207			`/*`
208			`* start hardware timer`
209			`*/`
210			`static void zf_timer_on(void)`
211			`{`
212			`unsigned int ctrl_reg = 0;`
213			`unsigned long flags;`
214
215			`spin_lock_irqsave(&zf_port_lock, flags);`
216
217			`zf_writeb(PULSE_LEN, 0xff);`
218
219			`zf_set_timer(ZF_CTIMEOUT, WD1);`
220
221			`/* user land ping */`
222			`next_heartbeat = jiffies + ZF_USER_TIMEO;`
223
224			`/* start the timer for internal ping */`
225			`mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);`
226
227			`/* start watchdog timer */`
228			`ctrl_reg = zf_get_control();`
229			`ctrl_reg \|= (ENABLE_WD1\|zf_action);`
230			`zf_set_control(ctrl_reg);`
231			`spin_unlock_irqrestore(&zf_port_lock, flags);`
232
233			`printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");`
234			`}`
235
236
237			`static void zf_ping(unsigned long data)`
238			`{`
239			`unsigned int ctrl_reg = 0;`
240			`unsigned long flags;`
241
242			`zf_writeb(COUNTER_2, 0xff);`
243
244			`if(time_before(jiffies, next_heartbeat)){`
245
246			`dprintk("time_before: %ld\n", next_heartbeat - jiffies);`
247
248			`/*`
249			`* reset event is activated by transition from 0 to 1 on`
250			`* RESET_WD1 bit and we assume that it is already zero...`
251			`*/`
252
253			`spin_lock_irqsave(&zf_port_lock, flags);`
254			`ctrl_reg = zf_get_control();`
255			`ctrl_reg \|= RESET_WD1;`
256			`zf_set_control(ctrl_reg);`
257
258			`/* ...and nothing changes until here */`
259			`ctrl_reg &= ~(RESET_WD1);`
260			`zf_set_control(ctrl_reg);`
261			`spin_unlock_irqrestore(&zf_port_lock, flags);`
262
263			`mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);`
264			`}else{`
265			`printk(KERN_CRIT PFX ": I will reset your machine\n");`
266			`}`
267			`}`
268
269			`static ssize_t zf_write(struct file file, const char __user buf, size_t count,`
270			`loff_t *ppos)`
271			`{`
272			`/* See if we got the magic character */`
273			`if(count){`
274
275			`/*`
276			`* no need to check for close confirmation`
277			`* no way to disable watchdog ;)`
278			`*/`
279			`if (!nowayout) {`
280			`size_t ofs;`
281
282			`/*`
283			`* note: just in case someone wrote the magic character`
284			`* five months ago...`
285			`*/`
286			`zf_expect_close = 0;`
287
288			`/* now scan */`
289			`for (ofs = 0; ofs != count; ofs++){`
290			`char c;`
291			`if (get_user(c, buf + ofs))`
292			`return -EFAULT;`
293			`if (c == 'V'){`
294			`zf_expect_close = 42;`
295			`dprintk("zf_expect_close = 42\n");`
296			`}`
297			`}`
298			`}`
299
300			`/*`
301			`* Well, anyhow someone wrote to us,`
302			`* we should return that favour`
303			`*/`
304			`next_heartbeat = jiffies + ZF_USER_TIMEO;`
305			`dprintk("user ping at %ld\n", jiffies);`
306
307			`}`
308
309			`return count;`
310			`}`
311
312			`static int zf_ioctl(struct inode inode, struct file file, unsigned int cmd,`
313			`unsigned long arg)`
314			`{`
315			`void __user argp = (void __user )arg;`
316			`int __user *p = argp;`
317			`switch (cmd) {`
318			`case WDIOC_GETSUPPORT:`
319			`if (copy_to_user(argp, &zf_info, sizeof(zf_info)))`
320			`return -EFAULT;`
321			`break;`
322
323			`case WDIOC_GETSTATUS:`
324			`case WDIOC_GETBOOTSTATUS:`
325			`return put_user(0, p);`
326
327			`case WDIOC_KEEPALIVE:`
328			`zf_ping(0);`
329			`break;`
330
331			`default:`
332			`return -ENOTTY;`
333			`}`
334
335			`return 0;`
336			`}`
337
338			`static int zf_open(struct inode inode, struct file file)`
339			`{`
340			`spin_lock(&zf_lock);`
341			`if(test_and_set_bit(0, &zf_is_open)) {`
342			`spin_unlock(&zf_lock);`
343			`return -EBUSY;`
344			`}`
345
346			`if (nowayout)`
347			`__module_get(THIS_MODULE);`
348
349			`spin_unlock(&zf_lock);`
350
351			`zf_timer_on();`
352
353			`return nonseekable_open(inode, file);`
354			`}`
355
356			`static int zf_close(struct inode inode, struct file file)`
357			`{`
358			`if(zf_expect_close == 42){`
359			`zf_timer_off();`
360			`} else {`
361			`del_timer(&zf_timer);`
362			`printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");`
363			`}`
364
365			`spin_lock(&zf_lock);`
366			`clear_bit(0, &zf_is_open);`
367			`spin_unlock(&zf_lock);`
368
369			`zf_expect_close = 0;`
370
371			`return 0;`
372			`}`
373
374			`/*`
375			`* Notifier for system down`
376			`*/`
377
378			`static int zf_notify_sys(struct notifier_block *this, unsigned long code,`
379			`void *unused)`
380			`{`
381			`if(code == SYS_DOWN \|\| code == SYS_HALT){`
382			`zf_timer_off();`
383			`}`
384
385			`return NOTIFY_DONE;`
386			`}`
387
388
389
390
391			`static const struct file_operations zf_fops = {`
392			`.owner = THIS_MODULE,`
393			`.llseek = no_llseek,`
394			`.write = zf_write,`
395			`.ioctl = zf_ioctl,`
396			`.open = zf_open,`
397			`.release = zf_close,`
398			`};`
399
400			`static struct miscdevice zf_miscdev = {`
401			`.minor = WATCHDOG_MINOR,`
402			`.name = "watchdog",`
403			`.fops = &zf_fops,`
404			`};`
405
406
407			`/*`
408			`* The device needs to learn about soft shutdowns in order to`
409			`* turn the timebomb registers off.`
410			`*/`
411			`static struct notifier_block zf_notifier = {`
412			`.notifier_call = zf_notify_sys,`
413			`};`
414
415			`static void __init zf_show_action(int act)`
416			`{`
417			`char *str[] = { "RESET", "SMI", "NMI", "SCI" };`
418
419			`printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);`
420			`}`
421
422			`static int __init zf_init(void)`
423			`{`
424			`int ret;`
425
426			`printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");`
427
428			`ret = zf_get_ZFL_version();`
429			`if ((!ret) \|\| (ret == 0xffff)) {`
430			`printk(KERN_WARNING PFX ": no ZF-Logic found\n");`
431			`return -ENODEV;`
432			`}`
433
434			`if((action <= 3) && (action >= 0)){`
435			`zf_action = zf_action>>action;`
436			`} else`
437			`action = 0;`
438
439			`zf_show_action(action);`
440
441			`if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){`
442			`printk(KERN_ERR "cannot reserve I/O ports at %d\n",`
443			`ZF_IOBASE);`
444			`ret = -EBUSY;`
445			`goto no_region;`
446			`}`
447
448			`ret = register_reboot_notifier(&zf_notifier);`
449			`if(ret){`
450			`printk(KERN_ERR "can't register reboot notifier (err=%d)\n",`
451			`ret);`
452			`goto no_reboot;`
453			`}`
454
455			`ret = misc_register(&zf_miscdev);`
456			`if (ret){`
457			`printk(KERN_ERR "can't misc_register on minor=%d\n",`
458			`WATCHDOG_MINOR);`
459			`goto no_misc;`
460			`}`
461
462			`zf_set_status(0);`
463			`zf_set_control(0);`
464
465			`return 0;`
466
467			`no_misc:`
468			`unregister_reboot_notifier(&zf_notifier);`
469			`no_reboot:`
470			`release_region(ZF_IOBASE, 3);`
471			`no_region:`
472			`return ret;`
473			`}`
474
475
476			`static void __exit zf_exit(void)`
477			`{`
478			`zf_timer_off();`
479
480			`misc_deregister(&zf_miscdev);`
481			`unregister_reboot_notifier(&zf_notifier);`
482			`release_region(ZF_IOBASE, 3);`
483			`}`
484
485			`module_init(zf_init);`
486			`module_exit(zf_exit);`