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23#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/init.h>
26#include <linux/miscdevice.h>
27#include <linux/watchdog.h>
28#include <linux/notifier.h>
29#include <linux/reboot.h>
30#include <linux/fs.h>
31#include <linux/pci.h>
32#include <linux/spinlock.h>
33#include <linux/uaccess.h>
34#include <linux/io.h>
35
36#define NAME "it8712f_wdt"
37
38MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
39MODULE_DESCRIPTION("IT8712F Watchdog Driver");
40MODULE_LICENSE("GPL");
41MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
42
43static int max_units = 255;
44static int margin = 60;
45module_param(margin, int, 0);
46MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
47
48static int nowayout = WATCHDOG_NOWAYOUT;
49module_param(nowayout, int, 0);
50MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
51
52static unsigned long wdt_open;
53static unsigned expect_close;
54static spinlock_t io_lock;
55static unsigned char revision;
56
57
58static unsigned short address;
59
60#define REG 0x2e
61#define VAL 0x2f
62
63#define LDN 0x07
64#define DEVID 0x20
65#define DEVREV 0x22
66#define ACT_REG 0x30
67#define BASE_REG 0x60
68
69#define IT8712F_DEVID 0x8712
70
71#define LDN_GPIO 0x07
72#define LDN_GAME 0x09
73
74#define WDT_CONTROL 0x71
75#define WDT_CONFIG 0x72
76#define WDT_TIMEOUT 0x73
77
78#define WDT_RESET_GAME 0x10
79#define WDT_RESET_KBD 0x20
80#define WDT_RESET_MOUSE 0x40
81#define WDT_RESET_CIR 0x80
82
83#define WDT_UNIT_SEC 0x80
84
85#define WDT_OUT_PWROK 0x10
86#define WDT_OUT_KRST 0x40
87
88static int superio_inb(int reg)
89{
90 outb(reg, REG);
91 return inb(VAL);
92}
93
94static void superio_outb(int val, int reg)
95{
96 outb(reg, REG);
97 outb(val, VAL);
98}
99
100static int superio_inw(int reg)
101{
102 int val;
103 outb(reg++, REG);
104 val = inb(VAL) << 8;
105 outb(reg, REG);
106 val |= inb(VAL);
107 return val;
108}
109
110static inline void superio_select(int ldn)
111{
112 outb(LDN, REG);
113 outb(ldn, VAL);
114}
115
116static inline void superio_enter(void)
117{
118 spin_lock(&io_lock);
119 outb(0x87, REG);
120 outb(0x01, REG);
121 outb(0x55, REG);
122 outb(0x55, REG);
123}
124
125static inline void superio_exit(void)
126{
127 outb(0x02, REG);
128 outb(0x02, VAL);
129 spin_unlock(&io_lock);
130}
131
132static inline void it8712f_wdt_ping(void)
133{
134 inb(address);
135}
136
137static void it8712f_wdt_update_margin(void)
138{
139 int config = WDT_OUT_KRST | WDT_OUT_PWROK;
140 int units = margin;
141
142
143
144
145 if (units <= max_units) {
146 config |= WDT_UNIT_SEC;
147 printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
148 } else {
149 units /= 60;
150 printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
151 }
152 superio_outb(config, WDT_CONFIG);
153
154 if (revision >= 0x08)
155 superio_outb(units >> 8, WDT_TIMEOUT + 1);
156 superio_outb(units, WDT_TIMEOUT);
157}
158
159static int it8712f_wdt_get_status(void)
160{
161 if (superio_inb(WDT_CONTROL) & 0x01)
162 return WDIOF_CARDRESET;
163 else
164 return 0;
165}
166
167static void it8712f_wdt_enable(void)
168{
169 printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
170 superio_enter();
171 superio_select(LDN_GPIO);
172
173 superio_outb(WDT_RESET_GAME, WDT_CONTROL);
174
175 it8712f_wdt_update_margin();
176
177 superio_exit();
178
179 it8712f_wdt_ping();
180}
181
182static void it8712f_wdt_disable(void)
183{
184 printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
185
186 superio_enter();
187 superio_select(LDN_GPIO);
188
189 superio_outb(0, WDT_CONFIG);
190 superio_outb(0, WDT_CONTROL);
191 if (revision >= 0x08)
192 superio_outb(0, WDT_TIMEOUT + 1);
193 superio_outb(0, WDT_TIMEOUT);
194
195 superio_exit();
196}
197
198static int it8712f_wdt_notify(struct notifier_block *this,
199 unsigned long code, void *unused)
200{
201 if (code == SYS_HALT || code == SYS_POWER_OFF)
202 if (!nowayout)
203 it8712f_wdt_disable();
204
205 return NOTIFY_DONE;
206}
207
208static struct notifier_block it8712f_wdt_notifier = {
209 .notifier_call = it8712f_wdt_notify,
210};
211
212static ssize_t it8712f_wdt_write(struct file *file, const char __user *data,
213 size_t len, loff_t *ppos)
214{
215
216 if (len) {
217 size_t i;
218
219 it8712f_wdt_ping();
220
221 expect_close = 0;
222 for (i = 0; i < len; ++i) {
223 char c;
224 if (get_user(c, data + i))
225 return -EFAULT;
226 if (c == 'V')
227 expect_close = 42;
228 }
229 }
230
231 return len;
232}
233
234static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
235 unsigned long arg)
236{
237 void __user *argp = (void __user *)arg;
238 int __user *p = argp;
239 static struct watchdog_info ident = {
240 .identity = "IT8712F Watchdog",
241 .firmware_version = 1,
242 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
243 WDIOF_MAGICCLOSE,
244 };
245 int value;
246
247 switch (cmd) {
248 case WDIOC_GETSUPPORT:
249 if (copy_to_user(argp, &ident, sizeof(ident)))
250 return -EFAULT;
251 return 0;
252 case WDIOC_GETSTATUS:
253 superio_enter();
254 superio_select(LDN_GPIO);
255
256 value = it8712f_wdt_get_status();
257
258 superio_exit();
259
260 return put_user(value, p);
261 case WDIOC_GETBOOTSTATUS:
262 return put_user(0, p);
263 case WDIOC_KEEPALIVE:
264 it8712f_wdt_ping();
265 return 0;
266 case WDIOC_SETTIMEOUT:
267 if (get_user(value, p))
268 return -EFAULT;
269 if (value < 1)
270 return -EINVAL;
271 if (value > (max_units * 60))
272 return -EINVAL;
273 margin = value;
274 superio_enter();
275 superio_select(LDN_GPIO);
276
277 it8712f_wdt_update_margin();
278
279 superio_exit();
280 it8712f_wdt_ping();
281
282 case WDIOC_GETTIMEOUT:
283 if (put_user(margin, p))
284 return -EFAULT;
285 return 0;
286 default:
287 return -ENOTTY;
288 }
289}
290
291static int it8712f_wdt_open(struct inode *inode, struct file *file)
292{
293
294 if (test_and_set_bit(0, &wdt_open))
295 return -EBUSY;
296 it8712f_wdt_enable();
297 return nonseekable_open(inode, file);
298}
299
300static int it8712f_wdt_release(struct inode *inode, struct file *file)
301{
302 if (expect_close != 42) {
303 printk(KERN_WARNING NAME
304 ": watchdog device closed unexpectedly, will not"
305 " disable the watchdog timer\n");
306 } else if (!nowayout) {
307 it8712f_wdt_disable();
308 }
309 expect_close = 0;
310 clear_bit(0, &wdt_open);
311
312 return 0;
313}
314
315static const struct file_operations it8712f_wdt_fops = {
316 .owner = THIS_MODULE,
317 .llseek = no_llseek,
318 .write = it8712f_wdt_write,
319 .unlocked_ioctl = it8712f_wdt_ioctl,
320 .open = it8712f_wdt_open,
321 .release = it8712f_wdt_release,
322};
323
324static struct miscdevice it8712f_wdt_miscdev = {
325 .minor = WATCHDOG_MINOR,
326 .name = "watchdog",
327 .fops = &it8712f_wdt_fops,
328};
329
330static int __init it8712f_wdt_find(unsigned short *address)
331{
332 int err = -ENODEV;
333 int chip_type;
334
335 superio_enter();
336 chip_type = superio_inw(DEVID);
337 if (chip_type != IT8712F_DEVID)
338 goto exit;
339
340 superio_select(LDN_GAME);
341 superio_outb(1, ACT_REG);
342 if (!(superio_inb(ACT_REG) & 0x01)) {
343 printk(KERN_ERR NAME ": Device not activated, skipping\n");
344 goto exit;
345 }
346
347 *address = superio_inw(BASE_REG);
348 if (*address == 0) {
349 printk(KERN_ERR NAME ": Base address not set, skipping\n");
350 goto exit;
351 }
352
353 err = 0;
354 revision = superio_inb(DEVREV) & 0x0f;
355
356
357 if (revision >= 0x08)
358 max_units = 65535;
359
360 if (margin > (max_units * 60))
361 margin = (max_units * 60);
362
363 printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
364 "using DogFood address 0x%x\n",
365 chip_type, revision, *address);
366
367exit:
368 superio_exit();
369 return err;
370}
371
372static int __init it8712f_wdt_init(void)
373{
374 int err = 0;
375
376 spin_lock_init(&io_lock);
377
378 if (it8712f_wdt_find(&address))
379 return -ENODEV;
380
381 if (!request_region(address, 1, "IT8712F Watchdog")) {
382 printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
383 return -EBUSY;
384 }
385
386 it8712f_wdt_disable();
387
388 err = register_reboot_notifier(&it8712f_wdt_notifier);
389 if (err) {
390 printk(KERN_ERR NAME ": unable to register reboot notifier\n");
391 goto out;
392 }
393
394 err = misc_register(&it8712f_wdt_miscdev);
395 if (err) {
396 printk(KERN_ERR NAME
397 ": cannot register miscdev on minor=%d (err=%d)\n",
398 WATCHDOG_MINOR, err);
399 goto reboot_out;
400 }
401
402 return 0;
403
404
405reboot_out:
406 unregister_reboot_notifier(&it8712f_wdt_notifier);
407out:
408 release_region(address, 1);
409 return err;
410}
411
412static void __exit it8712f_wdt_exit(void)
413{
414 misc_deregister(&it8712f_wdt_miscdev);
415 unregister_reboot_notifier(&it8712f_wdt_notifier);
416 release_region(address, 1);
417}
418
419module_init(it8712f_wdt_init);
420module_exit(it8712f_wdt_exit);
421
