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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 wdt_control_reg = WDT_RESET_GAME;
89module_param(wdt_control_reg, int, 0);
90MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
91 "register. The default WDT_RESET_GAME resets the timer on "
92 "game port reads that this driver generates. You can also "
93 "use KBD, MOUSE or CIR if you have some external way to "
94 "generate those interrupts.");
95
96static int superio_inb(int reg)
97{
98 outb(reg, REG);
99 return inb(VAL);
100}
101
102static void superio_outb(int val, int reg)
103{
104 outb(reg, REG);
105 outb(val, VAL);
106}
107
108static int superio_inw(int reg)
109{
110 int val;
111 outb(reg++, REG);
112 val = inb(VAL) << 8;
113 outb(reg, REG);
114 val |= inb(VAL);
115 return val;
116}
117
118static inline void superio_select(int ldn)
119{
120 outb(LDN, REG);
121 outb(ldn, VAL);
122}
123
124static inline void superio_enter(void)
125{
126 spin_lock(&io_lock);
127 outb(0x87, REG);
128 outb(0x01, REG);
129 outb(0x55, REG);
130 outb(0x55, REG);
131}
132
133static inline void superio_exit(void)
134{
135 outb(0x02, REG);
136 outb(0x02, VAL);
137 spin_unlock(&io_lock);
138}
139
140static inline void it8712f_wdt_ping(void)
141{
142 if (wdt_control_reg & WDT_RESET_GAME)
143 inb(address);
144}
145
146static void it8712f_wdt_update_margin(void)
147{
148 int config = WDT_OUT_KRST | WDT_OUT_PWROK;
149 int units = margin;
150
151
152
153
154 if (units <= max_units) {
155 config |= WDT_UNIT_SEC;
156 printk(KERN_INFO NAME ": timer margin %d seconds\n", units);
157 } else {
158 units /= 60;
159 printk(KERN_INFO NAME ": timer margin %d minutes\n", units);
160 }
161 superio_outb(config, WDT_CONFIG);
162
163 if (revision >= 0x08)
164 superio_outb(units >> 8, WDT_TIMEOUT + 1);
165 superio_outb(units, WDT_TIMEOUT);
166}
167
168static int it8712f_wdt_get_status(void)
169{
170 if (superio_inb(WDT_CONTROL) & 0x01)
171 return WDIOF_CARDRESET;
172 else
173 return 0;
174}
175
176static void it8712f_wdt_enable(void)
177{
178 printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
179 superio_enter();
180 superio_select(LDN_GPIO);
181
182 superio_outb(wdt_control_reg, WDT_CONTROL);
183
184 it8712f_wdt_update_margin();
185
186 superio_exit();
187
188 it8712f_wdt_ping();
189}
190
191static void it8712f_wdt_disable(void)
192{
193 printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
194
195 superio_enter();
196 superio_select(LDN_GPIO);
197
198 superio_outb(0, WDT_CONFIG);
199 superio_outb(0, WDT_CONTROL);
200 if (revision >= 0x08)
201 superio_outb(0, WDT_TIMEOUT + 1);
202 superio_outb(0, WDT_TIMEOUT);
203
204 superio_exit();
205}
206
207static int it8712f_wdt_notify(struct notifier_block *this,
208 unsigned long code, void *unused)
209{
210 if (code == SYS_HALT || code == SYS_POWER_OFF)
211 if (!nowayout)
212 it8712f_wdt_disable();
213
214 return NOTIFY_DONE;
215}
216
217static struct notifier_block it8712f_wdt_notifier = {
218 .notifier_call = it8712f_wdt_notify,
219};
220
221static ssize_t it8712f_wdt_write(struct file *file, const char __user *data,
222 size_t len, loff_t *ppos)
223{
224
225 if (len) {
226 size_t i;
227
228 it8712f_wdt_ping();
229
230 expect_close = 0;
231 for (i = 0; i < len; ++i) {
232 char c;
233 if (get_user(c, data + i))
234 return -EFAULT;
235 if (c == 'V')
236 expect_close = 42;
237 }
238 }
239
240 return len;
241}
242
243static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
244 unsigned long arg)
245{
246 void __user *argp = (void __user *)arg;
247 int __user *p = argp;
248 static const struct watchdog_info ident = {
249 .identity = "IT8712F Watchdog",
250 .firmware_version = 1,
251 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
252 WDIOF_MAGICCLOSE,
253 };
254 int value;
255
256 switch (cmd) {
257 case WDIOC_GETSUPPORT:
258 if (copy_to_user(argp, &ident, sizeof(ident)))
259 return -EFAULT;
260 return 0;
261 case WDIOC_GETSTATUS:
262 superio_enter();
263 superio_select(LDN_GPIO);
264
265 value = it8712f_wdt_get_status();
266
267 superio_exit();
268
269 return put_user(value, p);
270 case WDIOC_GETBOOTSTATUS:
271 return put_user(0, p);
272 case WDIOC_KEEPALIVE:
273 it8712f_wdt_ping();
274 return 0;
275 case WDIOC_SETTIMEOUT:
276 if (get_user(value, p))
277 return -EFAULT;
278 if (value < 1)
279 return -EINVAL;
280 if (value > (max_units * 60))
281 return -EINVAL;
282 margin = value;
283 superio_enter();
284 superio_select(LDN_GPIO);
285
286 it8712f_wdt_update_margin();
287
288 superio_exit();
289 it8712f_wdt_ping();
290
291 case WDIOC_GETTIMEOUT:
292 if (put_user(margin, p))
293 return -EFAULT;
294 return 0;
295 default:
296 return -ENOTTY;
297 }
298}
299
300static int it8712f_wdt_open(struct inode *inode, struct file *file)
301{
302
303 if (test_and_set_bit(0, &wdt_open))
304 return -EBUSY;
305 it8712f_wdt_enable();
306 return nonseekable_open(inode, file);
307}
308
309static int it8712f_wdt_release(struct inode *inode, struct file *file)
310{
311 if (expect_close != 42) {
312 printk(KERN_WARNING NAME
313 ": watchdog device closed unexpectedly, will not"
314 " disable the watchdog timer\n");
315 } else if (!nowayout) {
316 it8712f_wdt_disable();
317 }
318 expect_close = 0;
319 clear_bit(0, &wdt_open);
320
321 return 0;
322}
323
324static const struct file_operations it8712f_wdt_fops = {
325 .owner = THIS_MODULE,
326 .llseek = no_llseek,
327 .write = it8712f_wdt_write,
328 .unlocked_ioctl = it8712f_wdt_ioctl,
329 .open = it8712f_wdt_open,
330 .release = it8712f_wdt_release,
331};
332
333static struct miscdevice it8712f_wdt_miscdev = {
334 .minor = WATCHDOG_MINOR,
335 .name = "watchdog",
336 .fops = &it8712f_wdt_fops,
337};
338
339static int __init it8712f_wdt_find(unsigned short *address)
340{
341 int err = -ENODEV;
342 int chip_type;
343
344 superio_enter();
345 chip_type = superio_inw(DEVID);
346 if (chip_type != IT8712F_DEVID)
347 goto exit;
348
349 superio_select(LDN_GAME);
350 superio_outb(1, ACT_REG);
351 if (!(superio_inb(ACT_REG) & 0x01)) {
352 printk(KERN_ERR NAME ": Device not activated, skipping\n");
353 goto exit;
354 }
355
356 *address = superio_inw(BASE_REG);
357 if (*address == 0) {
358 printk(KERN_ERR NAME ": Base address not set, skipping\n");
359 goto exit;
360 }
361
362 err = 0;
363 revision = superio_inb(DEVREV) & 0x0f;
364
365
366 if (revision >= 0x08)
367 max_units = 65535;
368
369 if (margin > (max_units * 60))
370 margin = (max_units * 60);
371
372 printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
373 "using DogFood address 0x%x\n",
374 chip_type, revision, *address);
375
376exit:
377 superio_exit();
378 return err;
379}
380
381static int __init it8712f_wdt_init(void)
382{
383 int err = 0;
384
385 spin_lock_init(&io_lock);
386
387 if (it8712f_wdt_find(&address))
388 return -ENODEV;
389
390 if (!request_region(address, 1, "IT8712F Watchdog")) {
391 printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
392 return -EBUSY;
393 }
394
395 it8712f_wdt_disable();
396
397 err = register_reboot_notifier(&it8712f_wdt_notifier);
398 if (err) {
399 printk(KERN_ERR NAME ": unable to register reboot notifier\n");
400 goto out;
401 }
402
403 err = misc_register(&it8712f_wdt_miscdev);
404 if (err) {
405 printk(KERN_ERR NAME
406 ": cannot register miscdev on minor=%d (err=%d)\n",
407 WATCHDOG_MINOR, err);
408 goto reboot_out;
409 }
410
411 return 0;
412
413
414reboot_out:
415 unregister_reboot_notifier(&it8712f_wdt_notifier);
416out:
417 release_region(address, 1);
418 return err;
419}
420
421static void __exit it8712f_wdt_exit(void)
422{
423 misc_deregister(&it8712f_wdt_miscdev);
424 unregister_reboot_notifier(&it8712f_wdt_notifier);
425 release_region(address, 1);
426}
427
428module_init(it8712f_wdt_init);
429module_exit(it8712f_wdt_exit);
430
