Merge branch 'linux-2.6'
[linux-2.6] / drivers / watchdog / cpu5wdt.c
1 /*
2  * sma cpu5 watchdog driver
3  *
4  * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  *
20  */
21
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/types.h>
25 #include <linux/errno.h>
26 #include <linux/miscdevice.h>
27 #include <linux/fs.h>
28 #include <linux/init.h>
29 #include <linux/ioport.h>
30 #include <linux/timer.h>
31 #include <linux/completion.h>
32 #include <linux/jiffies.h>
33 #include <asm/io.h>
34 #include <asm/uaccess.h>
35
36 #include <linux/watchdog.h>
37
38 /* adjustable parameters */
39
40 static int verbose = 0;
41 static int port = 0x91;
42 static int ticks = 10000;
43
44 #define PFX                     "cpu5wdt: "
45
46 #define CPU5WDT_EXTENT          0x0A
47
48 #define CPU5WDT_STATUS_REG      0x00
49 #define CPU5WDT_TIME_A_REG      0x02
50 #define CPU5WDT_TIME_B_REG      0x03
51 #define CPU5WDT_MODE_REG        0x04
52 #define CPU5WDT_TRIGGER_REG     0x07
53 #define CPU5WDT_ENABLE_REG      0x08
54 #define CPU5WDT_RESET_REG       0x09
55
56 #define CPU5WDT_INTERVAL        (HZ/10+1)
57
58 /* some device data */
59
60 static struct {
61         struct completion stop;
62         volatile int running;
63         struct timer_list timer;
64         volatile int queue;
65         int default_ticks;
66         unsigned long inuse;
67 } cpu5wdt_device;
68
69 /* generic helper functions */
70
71 static void cpu5wdt_trigger(unsigned long unused)
72 {
73         if ( verbose > 2 )
74                 printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);
75
76         if( cpu5wdt_device.running )
77                 ticks--;
78
79         /* keep watchdog alive */
80         outb(1, port + CPU5WDT_TRIGGER_REG);
81
82         /* requeue?? */
83         if (cpu5wdt_device.queue && ticks)
84                 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
85         else {
86                 /* ticks doesn't matter anyway */
87                 complete(&cpu5wdt_device.stop);
88         }
89
90 }
91
92 static void cpu5wdt_reset(void)
93 {
94         ticks = cpu5wdt_device.default_ticks;
95
96         if ( verbose )
97                 printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);
98
99 }
100
101 static void cpu5wdt_start(void)
102 {
103         if ( !cpu5wdt_device.queue ) {
104                 cpu5wdt_device.queue = 1;
105                 outb(0, port + CPU5WDT_TIME_A_REG);
106                 outb(0, port + CPU5WDT_TIME_B_REG);
107                 outb(1, port + CPU5WDT_MODE_REG);
108                 outb(0, port + CPU5WDT_RESET_REG);
109                 outb(0, port + CPU5WDT_ENABLE_REG);
110                 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
111         }
112         /* if process dies, counter is not decremented */
113         cpu5wdt_device.running++;
114 }
115
116 static int cpu5wdt_stop(void)
117 {
118         if ( cpu5wdt_device.running )
119                 cpu5wdt_device.running = 0;
120
121         ticks = cpu5wdt_device.default_ticks;
122
123         if ( verbose )
124                 printk(KERN_CRIT PFX "stop not possible\n");
125
126         return -EIO;
127 }
128
129 /* filesystem operations */
130
131 static int cpu5wdt_open(struct inode *inode, struct file *file)
132 {
133         if ( test_and_set_bit(0, &cpu5wdt_device.inuse) )
134                 return -EBUSY;
135
136         return nonseekable_open(inode, file);
137 }
138
139 static int cpu5wdt_release(struct inode *inode, struct file *file)
140 {
141         clear_bit(0, &cpu5wdt_device.inuse);
142         return 0;
143 }
144
145 static int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
146 {
147         void __user *argp = (void __user *)arg;
148         unsigned int value;
149         static struct watchdog_info ident =
150         {
151                 .options = WDIOF_CARDRESET,
152                 .identity = "CPU5 WDT",
153         };
154
155         switch(cmd) {
156                 case WDIOC_KEEPALIVE:
157                         cpu5wdt_reset();
158                         break;
159                 case WDIOC_GETSTATUS:
160                         value = inb(port + CPU5WDT_STATUS_REG);
161                         value = (value >> 2) & 1;
162                         if ( copy_to_user(argp, &value, sizeof(int)) )
163                                 return -EFAULT;
164                         break;
165                 case WDIOC_GETBOOTSTATUS:
166                         if ( copy_to_user(argp, &value, sizeof(int)) )
167                                 return -EFAULT;
168                         break;
169                 case WDIOC_GETSUPPORT:
170                         if ( copy_to_user(argp, &ident, sizeof(ident)) )
171                                 return -EFAULT;
172                         break;
173                 case WDIOC_SETOPTIONS:
174                         if ( copy_from_user(&value, argp, sizeof(int)) )
175                                 return -EFAULT;
176                         switch(value) {
177                                 case WDIOS_ENABLECARD:
178                                         cpu5wdt_start();
179                                         break;
180                                 case WDIOS_DISABLECARD:
181                                         return cpu5wdt_stop();
182                                 default:
183                                         return -EINVAL;
184                         }
185                         break;
186                 default:
187                         return -ENOTTY;
188         }
189         return 0;
190 }
191
192 static ssize_t cpu5wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
193 {
194         if ( !count )
195                 return -EIO;
196
197         cpu5wdt_reset();
198
199         return count;
200 }
201
202 static const struct file_operations cpu5wdt_fops = {
203         .owner          = THIS_MODULE,
204         .llseek         = no_llseek,
205         .ioctl          = cpu5wdt_ioctl,
206         .open           = cpu5wdt_open,
207         .write          = cpu5wdt_write,
208         .release        = cpu5wdt_release,
209 };
210
211 static struct miscdevice cpu5wdt_misc = {
212         .minor  = WATCHDOG_MINOR,
213         .name   = "watchdog",
214         .fops   = &cpu5wdt_fops,
215 };
216
217 /* init/exit function */
218
219 static int __devinit cpu5wdt_init(void)
220 {
221         unsigned int val;
222         int err;
223
224         if ( verbose )
225                 printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);
226
227         if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {
228                 printk(KERN_ERR PFX "request_region failed\n");
229                 err = -EBUSY;
230                 goto no_port;
231         }
232
233         if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {
234                 printk(KERN_ERR PFX "misc_register failed\n");
235                 goto no_misc;
236         }
237
238         /* watchdog reboot? */
239         val = inb(port + CPU5WDT_STATUS_REG);
240         val = (val >> 2) & 1;
241         if ( !val )
242                 printk(KERN_INFO PFX "sorry, was my fault\n");
243
244         init_completion(&cpu5wdt_device.stop);
245         cpu5wdt_device.queue = 0;
246
247         clear_bit(0, &cpu5wdt_device.inuse);
248
249         setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
250
251         cpu5wdt_device.default_ticks = ticks;
252
253         printk(KERN_INFO PFX "init success\n");
254
255         return 0;
256
257 no_misc:
258         release_region(port, CPU5WDT_EXTENT);
259 no_port:
260         return err;
261 }
262
263 static int __devinit cpu5wdt_init_module(void)
264 {
265         return cpu5wdt_init();
266 }
267
268 static void __devexit cpu5wdt_exit(void)
269 {
270         if ( cpu5wdt_device.queue ) {
271                 cpu5wdt_device.queue = 0;
272                 wait_for_completion(&cpu5wdt_device.stop);
273         }
274
275         misc_deregister(&cpu5wdt_misc);
276
277         release_region(port, CPU5WDT_EXTENT);
278
279 }
280
281 static void __devexit cpu5wdt_exit_module(void)
282 {
283         cpu5wdt_exit();
284 }
285
286 /* module entry points */
287
288 module_init(cpu5wdt_init_module);
289 module_exit(cpu5wdt_exit_module);
290
291 MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
292 MODULE_DESCRIPTION("sma cpu5 watchdog driver");
293 MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
294 MODULE_LICENSE("GPL");
295 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
296
297 module_param(port, int, 0);
298 MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
299
300 module_param(verbose, int, 0);
301 MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
302
303 module_param(ticks, int, 0);
304 MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");