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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [machzwd.c] - Blame information for rev 1275

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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/config.h>
#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/slab.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_LICENSE("GPL");
MODULE_PARM(action, "i");
MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*)  1 = SMI  2 = NMI  3 = SCI");
 
#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout = 0;
#endif
 
MODULE_PARM(nowayout,"i");
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_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;
static int zf_action = GEN_RESET;
static int zf_is_open = 0;
static int zf_expect_close = 0;
static spinlock_t zf_lock;
static spinlock_t zf_port_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
 */
 
static 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;
        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 */
        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);
        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);
 
                zf_timer.expires = jiffies + ZF_HW_TIMEO;
                add_timer(&zf_timer);
        }else{
                printk(KERN_CRIT 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 ;)
                 */
                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 = 1;
                                        dprintk("zf_expect_close 1\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 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)
{
        switch(cmd){
                case WDIOC_GETSUPPORT:
                        if (copy_to_user((struct watchdog_info *)arg,
                                         &zf_info, sizeof(zf_info)))
                                return -EFAULT;
                        break;
 
                case WDIOC_GETSTATUS:
                        if (copy_to_user((int *)arg, &zf_is_open, sizeof(int)))
                                return -EFAULT;
                        break;
 
                case WDIOC_KEEPALIVE:
                        zf_ping(0);
                        break;
 
                default:
                        return -ENOTTY;
        }
 
        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;
                        }
 
                        if (nowayout) {
                                MOD_INC_USE_COUNT;
                        }
                        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(KERN_ERR 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 = {
        owner:          THIS_MODULE,
        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,
 
};
 
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();
        printk("%#x\n", ret);
        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);
 
        spin_lock_init(&zf_lock);
        spin_lock_init(&zf_port_lock);
 
        ret = misc_register(&zf_miscdev);
        if (ret){
                printk(KERN_ERR "can't misc_register on minor=%d\n",
                                                        WATCHDOG_MINOR);
                goto out;
        }
 
        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;
        }
 
        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);

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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [char/] [machzwd.c] - Blame information for rev 1275

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
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/config.h>`
32			`#include <linux/module.h>`
33			`#include <linux/version.h>`
34			`#include <linux/types.h>`
35			`#include <linux/errno.h>`
36			`#include <linux/kernel.h>`
37			`#include <linux/timer.h>`
38			`#include <linux/sched.h>`
39			`#include <linux/miscdevice.h>`
40			`#include <linux/watchdog.h>`
41			`#include <linux/slab.h>`
42			`#include <linux/ioport.h>`
43			`#include <linux/fcntl.h>`
44			`#include <linux/smp_lock.h>`
45			`#include <asm/io.h>`
46			`#include <asm/uaccess.h>`
47			`#include <asm/system.h>`
48			`#include <linux/notifier.h>`
49			`#include <linux/reboot.h>`
50			`#include <linux/init.h>`
51
52
53			`/* ports */`
54			`#define ZF_IOBASE 0x218`
55			`#define INDEX 0x218`
56			`#define DATA_B 0x219`
57			`#define DATA_W 0x21A`
58			`#define DATA_D 0x21A`
59
60			`/* indexes / / size */`
61			`#define ZFL_VERSION 0x02 /* 16 */`
62			`#define CONTROL 0x10 /* 16 */`
63			`#define STATUS 0x12 /* 8 */`
64			`#define COUNTER_1 0x0C /* 16 */`
65			`#define COUNTER_2 0x0E /* 8 */`
66			`#define PULSE_LEN 0x0F /* 8 */`
67
68			`/* controls */`
69			`#define ENABLE_WD1 0x0001`
70			`#define ENABLE_WD2 0x0002`
71			`#define RESET_WD1 0x0010`
72			`#define RESET_WD2 0x0020`
73			`#define GEN_SCI 0x0100`
74			`#define GEN_NMI 0x0200`
75			`#define GEN_SMI 0x0400`
76			`#define GEN_RESET 0x0800`
77
78
79			`/* utilities */`
80
81			`#define WD1 0`
82			`#define WD2 1`
83
84			`#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }`
85			`#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }`
86			`#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)`
87
88
89			`static unsigned short zf_readw(unsigned char port)`
90			`{`
91			`outb(port, INDEX);`
92			`return inw(DATA_W);`
93			`}`
94
95			`static unsigned short zf_readb(unsigned char port)`
96			`{`
97			`outb(port, INDEX);`
98			`return inb(DATA_B);`
99			`}`
100
101
102			`MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");`
103			`MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");`
104			`MODULE_LICENSE("GPL");`
105			`MODULE_PARM(action, "i");`
106			`MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");`
107
108			`#ifdef CONFIG_WATCHDOG_NOWAYOUT`
109			`static int nowayout = 1;`
110			`#else`
111			`static int nowayout = 0;`
112			`#endif`
113
114			`MODULE_PARM(nowayout,"i");`
115			`MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");`
116
117			`#define PFX "machzwd"`
118
119			`static struct watchdog_info zf_info = {`
120			`options: WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,`
121			`firmware_version: 1,`
122			`identity: "ZF-Logic watchdog"`
123			`};`
124
125
126			`/*`
127			`* action refers to action taken when watchdog resets`
128			`* 0 = GEN_RESET`
129			`* 1 = GEN_SMI`
130			`* 2 = GEN_NMI`
131			`* 3 = GEN_SCI`
132			`* defaults to GEN_RESET (0)`
133			`*/`
134			`static int action = 0;`
135			`static int zf_action = GEN_RESET;`
136			`static int zf_is_open = 0;`
137			`static int zf_expect_close = 0;`
138			`static spinlock_t zf_lock;`
139			`static spinlock_t zf_port_lock;`
140			`static struct timer_list zf_timer;`
141			`static unsigned long next_heartbeat = 0;`
142
143
144			`/* timeout for user land heart beat (10 seconds) */`
145			`#define ZF_USER_TIMEO (HZ*10)`
146
147			`/* timeout for hardware watchdog (~500ms) */`
148			`#define ZF_HW_TIMEO (HZ/2)`
149
150			`/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */`
151			`#define ZF_CTIMEOUT 0xffff`
152
153			`#ifndef ZF_DEBUG`
154			`# define dprintk(format, args...)`
155			`#else`
156			`# define dprintk(format, args...) printk(KERN_DEBUG PFX; ":" __FUNCTION__ ":%d: " format, __LINE__ , ## args)`
157			`#endif`
158
159
160			`/* STATUS register functions */`
161
162			`static inline unsigned char zf_get_status(void)`
163			`{`
164			`return zf_readb(STATUS);`
165			`}`
166
167			`static inline void zf_set_status(unsigned char new)`
168			`{`
169			`zf_writeb(STATUS, new);`
170			`}`
171
172
173			`/* CONTROL register functions */`
174
175			`static inline unsigned short zf_get_control(void)`
176			`{`
177			`return zf_readw(CONTROL);`
178			`}`
179
180			`static inline void zf_set_control(unsigned short new)`
181			`{`
182			`zf_writew(CONTROL, new);`
183			`}`
184
185
186			`/* WD#? counter functions */`
187			`/*`
188			`* Just get current counter value`
189			`*/`
190
191			`static inline unsigned short zf_get_timer(unsigned char n)`
192			`{`
193			`switch(n){`
194			`case WD1:`
195			`return zf_readw(COUNTER_1);`
196			`case WD2:`
197			`return zf_readb(COUNTER_2);`
198			`default:`
199			`return 0;`
200			`}`
201			`}`
202
203			`/*`
204			`* Just set counter value`
205			`*/`
206
207			`static inline void zf_set_timer(unsigned short new, unsigned char n)`
208			`{`
209			`switch(n){`
210			`case WD1:`
211			`zf_writew(COUNTER_1, new);`
212			`case WD2:`
213			`zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);`
214			`default:`
215			`return;`
216			`}`
217			`}`
218
219			`/*`
220			`* stop hardware timer`
221			`*/`
222			`static void zf_timer_off(void)`
223			`{`
224			`unsigned int ctrl_reg = 0;`
225			`unsigned long flags;`
226
227			`/* stop internal ping */`
228			`del_timer_sync(&zf_timer);`
229
230			`spin_lock_irqsave(&zf_port_lock, flags);`
231			`/* stop watchdog timer */`
232			`ctrl_reg = zf_get_control();`
233			`ctrl_reg \|= (ENABLE_WD1\|ENABLE_WD2); /* disable wd1 and wd2 */`
234			`ctrl_reg &= ~(ENABLE_WD1\|ENABLE_WD2);`
235			`zf_set_control(ctrl_reg);`
236			`spin_unlock_irqrestore(&zf_port_lock, flags);`
237
238			`printk(KERN_INFO PFX ": Watchdog timer is now disabled\n");`
239			`}`
240
241
242			`/*`
243			`* start hardware timer`
244			`*/`
245			`static void zf_timer_on(void)`
246			`{`
247			`unsigned int ctrl_reg = 0;`
248			`unsigned long flags;`
249
250			`spin_lock_irqsave(&zf_port_lock, flags);`
251
252			`zf_writeb(PULSE_LEN, 0xff);`
253
254			`zf_set_timer(ZF_CTIMEOUT, WD1);`
255
256			`/* user land ping */`
257			`next_heartbeat = jiffies + ZF_USER_TIMEO;`
258
259			`/* start the timer for internal ping */`
260			`zf_timer.expires = jiffies + ZF_HW_TIMEO;`
261
262			`add_timer(&zf_timer);`
263
264			`/* start watchdog timer */`
265			`ctrl_reg = zf_get_control();`
266			`ctrl_reg \|= (ENABLE_WD1\|zf_action);`
267			`zf_set_control(ctrl_reg);`
268			`spin_unlock_irqrestore(&zf_port_lock, flags);`
269
270			`printk(KERN_INFO PFX ": Watchdog timer is now enabled\n");`
271			`}`
272
273
274			`static void zf_ping(unsigned long data)`
275			`{`
276			`unsigned int ctrl_reg = 0;`
277			`unsigned long flags;`
278
279			`zf_writeb(COUNTER_2, 0xff);`
280
281			`if(time_before(jiffies, next_heartbeat)){`
282
283			`dprintk("time_before: %ld\n", next_heartbeat - jiffies);`
284
285			`/*`
286			`* reset event is activated by transition from 0 to 1 on`
287			`* RESET_WD1 bit and we assume that it is already zero...`
288			`*/`
289
290			`spin_lock_irqsave(&zf_port_lock, flags);`
291			`ctrl_reg = zf_get_control();`
292			`ctrl_reg \|= RESET_WD1;`
293			`zf_set_control(ctrl_reg);`
294
295			`/* ...and nothing changes until here */`
296			`ctrl_reg &= ~(RESET_WD1);`
297			`zf_set_control(ctrl_reg);`
298			`spin_unlock_irqrestore(&zf_port_lock, flags);`
299
300			`zf_timer.expires = jiffies + ZF_HW_TIMEO;`
301			`add_timer(&zf_timer);`
302			`}else{`
303			`printk(KERN_CRIT PFX ": I will reset your machine\n");`
304			`}`
305			`}`
306
307			`static ssize_t zf_write(struct file file, const char buf, size_t count,`
308			`loff_t *ppos)`
309			`{`
310			`/* Can't seek (pwrite) on this device */`
311			`if (ppos != &file->f_pos)`
312			`return -ESPIPE;`
313
314			`/* See if we got the magic character */`
315			`if(count){`
316
317			`/*`
318			`* no need to check for close confirmation`
319			`* no way to disable watchdog ;)`
320			`*/`
321			`if (!nowayout) {`
322			`size_t ofs;`
323
324			`/*`
325			`* note: just in case someone wrote the`
326			`* magic character five months ago...`
327			`*/`
328			`zf_expect_close = 0;`
329
330			`/* now scan */`
331			`for(ofs = 0; ofs != count; ofs++){`
332			`char c;`
333			`if(get_user(c, buf+ofs))`
334			`return -EFAULT;`
335			`if(c == 'V'){`
336			`zf_expect_close = 1;`
337			`dprintk("zf_expect_close 1\n");`
338			`}`
339			`}`
340			`}`
341			`/*`
342			`* Well, anyhow someone wrote to us,`
343			`* we should return that favour`
344			`*/`
345			`next_heartbeat = jiffies + ZF_USER_TIMEO;`
346			`dprintk("user ping at %ld\n", jiffies);`
347
348			`return 1;`
349			`}`
350
351			`return 0;`
352			`}`
353
354			`static ssize_t zf_read(struct file file, char buf, size_t count,`
355			`loff_t *ppos)`
356			`{`
357			`return -EINVAL;`
358			`}`
359
360
361
362			`static int zf_ioctl(struct inode inode, struct file file, unsigned int cmd,`
363			`unsigned long arg)`
364			`{`
365			`switch(cmd){`
366			`case WDIOC_GETSUPPORT:`
367			`if (copy_to_user((struct watchdog_info *)arg,`
368			`&zf_info, sizeof(zf_info)))`
369			`return -EFAULT;`
370			`break;`
371
372			`case WDIOC_GETSTATUS:`
373			`if (copy_to_user((int *)arg, &zf_is_open, sizeof(int)))`
374			`return -EFAULT;`
375			`break;`
376
377			`case WDIOC_KEEPALIVE:`
378			`zf_ping(0);`
379			`break;`
380
381			`default:`
382			`return -ENOTTY;`
383			`}`
384
385			`return 0;`
386			`}`
387
388			`static int zf_open(struct inode inode, struct file file)`
389			`{`
390			`switch(MINOR(inode->i_rdev)){`
391			`case WATCHDOG_MINOR:`
392			`spin_lock(&zf_lock);`
393			`if(zf_is_open){`
394			`spin_unlock(&zf_lock);`
395			`return -EBUSY;`
396			`}`
397
398			`if (nowayout) {`
399			`MOD_INC_USE_COUNT;`
400			`}`
401			`zf_is_open = 1;`
402
403			`spin_unlock(&zf_lock);`
404
405			`zf_timer_on();`
406
407			`return 0;`
408			`default:`
409			`return -ENODEV;`
410			`}`
411			`}`
412
413			`static int zf_close(struct inode inode, struct file file)`
414			`{`
415			`if(MINOR(inode->i_rdev) == WATCHDOG_MINOR){`
416
417			`if(zf_expect_close){`
418			`zf_timer_off();`
419			`} else {`
420			`del_timer(&zf_timer);`
421			`printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n");`
422			`}`
423
424			`spin_lock(&zf_lock);`
425			`zf_is_open = 0;`
426			`spin_unlock(&zf_lock);`
427
428			`zf_expect_close = 0;`
429			`}`
430
431			`return 0;`
432			`}`
433
434			`/*`
435			`* Notifier for system down`
436			`*/`
437
438			`static int zf_notify_sys(struct notifier_block *this, unsigned long code,`
439			`void *unused)`
440			`{`
441			`if(code == SYS_DOWN \|\| code == SYS_HALT){`
442			`zf_timer_off();`
443			`}`
444
445			`return NOTIFY_DONE;`
446			`}`
447
448
449
450
451			`static struct file_operations zf_fops = {`
452			`owner: THIS_MODULE,`
453			`read: zf_read,`
454			`write: zf_write,`
455			`ioctl: zf_ioctl,`
456			`open: zf_open,`
457			`release: zf_close,`
458			`};`
459
460			`static struct miscdevice zf_miscdev = {`
461			`WATCHDOG_MINOR,`
462			`"watchdog",`
463			`&zf_fops`
464			`};`
465
466
467			`/*`
468			`* The device needs to learn about soft shutdowns in order to`
469			`* turn the timebomb registers off.`
470			`*/`
471			`static struct notifier_block zf_notifier = {`
472			`zf_notify_sys,`
473			`NULL,`
474
475			`};`
476
477			`static void __init zf_show_action(int act)`
478			`{`
479			`char *str[] = { "RESET", "SMI", "NMI", "SCI" };`
480
481			`printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]);`
482			`}`
483
484			`static int __init zf_init(void)`
485			`{`
486			`int ret;`
487
488			`printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n");`
489
490			`ret = zf_get_ZFL_version();`
491			`printk("%#x\n", ret);`
492			`if((!ret) \|\| (ret != 0xffff)){`
493			`printk(KERN_WARNING PFX ": no ZF-Logic found\n");`
494			`return -ENODEV;`
495			`}`
496
497			`if((action <= 3) && (action >= 0)){`
498			`zf_action = zf_action>>action;`
499			`} else`
500			`action = 0;`
501
502			`zf_show_action(action);`
503
504			`spin_lock_init(&zf_lock);`
505			`spin_lock_init(&zf_port_lock);`
506
507			`ret = misc_register(&zf_miscdev);`
508			`if (ret){`
509			`printk(KERN_ERR "can't misc_register on minor=%d\n",`
510			`WATCHDOG_MINOR);`
511			`goto out;`
512			`}`
513
514			`if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){`
515			`printk(KERN_ERR "cannot reserve I/O ports at %d\n",`
516			`ZF_IOBASE);`
517			`ret = -EBUSY;`
518			`goto no_region;`
519			`}`
520
521			`ret = register_reboot_notifier(&zf_notifier);`
522			`if(ret){`
523			`printk(KERN_ERR "can't register reboot notifier (err=%d)\n",`
524			`ret);`
525			`goto no_reboot;`
526			`}`
527
528			`zf_set_status(0);`
529			`zf_set_control(0);`
530
531			`/* this is the timer that will do the hard work */`
532			`init_timer(&zf_timer);`
533			`zf_timer.function = zf_ping;`
534			`zf_timer.data = 0;`
535
536			`return 0;`
537
538			`no_reboot:`
539			`release_region(ZF_IOBASE, 3);`
540			`no_region:`
541			`misc_deregister(&zf_miscdev);`
542			`out:`
543			`return ret;`
544			`}`
545
546
547			`void __exit zf_exit(void)`
548			`{`
549			`zf_timer_off();`
550
551			`misc_deregister(&zf_miscdev);`
552			`unregister_reboot_notifier(&zf_notifier);`
553			`release_region(ZF_IOBASE, 3);`
554			`}`
555
556			`module_init(zf_init);`
557			`module_exit(zf_exit);`