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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
39
40static int verbose = 0;
41static int port = 0x91;
42static 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
59
60static 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
70
71static 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
80 outb(1, port + CPU5WDT_TRIGGER_REG);
81
82
83 if (cpu5wdt_device.queue && ticks)
84 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
85 else {
86
87 complete(&cpu5wdt_device.stop);
88 }
89
90}
91
92static 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
101static 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
113 cpu5wdt_device.running++;
114}
115
116static 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
130
131static 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
139static int cpu5wdt_release(struct inode *inode, struct file *file)
140{
141 clear_bit(0, &cpu5wdt_device.inuse);
142 return 0;
143}
144
145static 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
192static 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
202static 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
211static struct miscdevice cpu5wdt_misc = {
212 .minor = WATCHDOG_MINOR,
213 .name = "watchdog",
214 .fops = &cpu5wdt_fops,
215};
216
217
218
219static 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
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
257no_misc:
258 release_region(port, CPU5WDT_EXTENT);
259no_port:
260 return err;
261}
262
263static int __devinit cpu5wdt_init_module(void)
264{
265 return cpu5wdt_init();
266}
267
268static 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
281static void __devexit cpu5wdt_exit_module(void)
282{
283 cpu5wdt_exit();
284}
285
286
287
288module_init(cpu5wdt_init_module);
289module_exit(cpu5wdt_exit_module);
290
291MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
292MODULE_DESCRIPTION("sma cpu5 watchdog driver");
293MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
294MODULE_LICENSE("GPL");
295MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
296
297module_param(port, int, 0);
298MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
299
300module_param(verbose, int, 0);
301MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
302
303module_param(ticks, int, 0);
304MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
305
