PCI: make no_pci_devices() use the pci_bus_type list
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / watchdog / it8712f_wdt.c
blob445b7e812112572ba82925576b6129ebafe8aed5
1 /*
2 * IT8712F "Smart Guardian" Watchdog support
4 * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
6 * Based on info and code taken from:
8 * drivers/char/watchdog/scx200_wdt.c
9 * drivers/hwmon/it87.c
10 * IT8712F EC-LPC I/O Preliminary Specification 0.8.2
11 * IT8712F EC-LPC I/O Preliminary Specification 0.9.3
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of the
16 * License, or (at your option) any later version.
18 * The author(s) of this software shall not be held liable for damages
19 * of any nature resulting due to the use of this software. This
20 * software is provided AS-IS with no warranties.
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>
34 #include <asm/uaccess.h>
35 #include <asm/io.h>
37 #define NAME "it8712f_wdt"
39 MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
40 MODULE_DESCRIPTION("IT8712F Watchdog Driver");
41 MODULE_LICENSE("GPL");
42 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
44 static int max_units = 255;
45 static int margin = 60; /* in seconds */
46 module_param(margin, int, 0);
47 MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
49 static int nowayout = WATCHDOG_NOWAYOUT;
50 module_param(nowayout, int, 0);
51 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
53 static struct semaphore it8712f_wdt_sem;
54 static unsigned expect_close;
55 static spinlock_t io_lock;
56 static unsigned char revision;
58 /* Dog Food address - We use the game port address */
59 static unsigned short address;
61 #define REG 0x2e /* The register to read/write */
62 #define VAL 0x2f /* The value to read/write */
64 #define LDN 0x07 /* Register: Logical device select */
65 #define DEVID 0x20 /* Register: Device ID */
66 #define DEVREV 0x22 /* Register: Device Revision */
67 #define ACT_REG 0x30 /* LDN Register: Activation */
68 #define BASE_REG 0x60 /* LDN Register: Base address */
70 #define IT8712F_DEVID 0x8712
72 #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
73 #define LDN_GAME 0x09 /* Game Port */
75 #define WDT_CONTROL 0x71 /* WDT Register: Control */
76 #define WDT_CONFIG 0x72 /* WDT Register: Configuration */
77 #define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
79 #define WDT_RESET_GAME 0x10
80 #define WDT_RESET_KBD 0x20
81 #define WDT_RESET_MOUSE 0x40
82 #define WDT_RESET_CIR 0x80
84 #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
86 #define WDT_OUT_PWROK 0x10
87 #define WDT_OUT_KRST 0x40
89 static int
90 superio_inb(int reg)
92 outb(reg, REG);
93 return inb(VAL);
96 static void
97 superio_outb(int val, int reg)
99 outb(reg, REG);
100 outb(val, VAL);
103 static int
104 superio_inw(int reg)
106 int val;
107 outb(reg++, REG);
108 val = inb(VAL) << 8;
109 outb(reg, REG);
110 val |= inb(VAL);
111 return val;
114 static inline void
115 superio_select(int ldn)
117 outb(LDN, REG);
118 outb(ldn, VAL);
121 static inline void
122 superio_enter(void)
124 spin_lock(&io_lock);
125 outb(0x87, REG);
126 outb(0x01, REG);
127 outb(0x55, REG);
128 outb(0x55, REG);
131 static inline void
132 superio_exit(void)
134 outb(0x02, REG);
135 outb(0x02, VAL);
136 spin_unlock(&io_lock);
139 static inline void
140 it8712f_wdt_ping(void)
142 inb(address);
145 static void
146 it8712f_wdt_update_margin(void)
148 int config = WDT_OUT_KRST | WDT_OUT_PWROK;
149 int units = margin;
151 /* Switch to minutes precision if the configured margin
152 * value does not fit within the register width.
154 if (units <= max_units) {
155 config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */
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);
161 superio_outb(config, WDT_CONFIG);
163 if (revision >= 0x08)
164 superio_outb(units >> 8, WDT_TIMEOUT + 1);
165 superio_outb(units, WDT_TIMEOUT);
168 static int
169 it8712f_wdt_get_status(void)
171 if (superio_inb(WDT_CONTROL) & 0x01)
172 return WDIOF_CARDRESET;
173 else
174 return 0;
177 static void
178 it8712f_wdt_enable(void)
180 printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
181 superio_enter();
182 superio_select(LDN_GPIO);
184 superio_outb(WDT_RESET_GAME, WDT_CONTROL);
186 it8712f_wdt_update_margin();
188 superio_exit();
190 it8712f_wdt_ping();
193 static void
194 it8712f_wdt_disable(void)
196 printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
198 superio_enter();
199 superio_select(LDN_GPIO);
201 superio_outb(0, WDT_CONFIG);
202 superio_outb(0, WDT_CONTROL);
203 if (revision >= 0x08)
204 superio_outb(0, WDT_TIMEOUT + 1);
205 superio_outb(0, WDT_TIMEOUT);
207 superio_exit();
210 static int
211 it8712f_wdt_notify(struct notifier_block *this,
212 unsigned long code, void *unused)
214 if (code == SYS_HALT || code == SYS_POWER_OFF)
215 if (!nowayout)
216 it8712f_wdt_disable();
218 return NOTIFY_DONE;
221 static struct notifier_block it8712f_wdt_notifier = {
222 .notifier_call = it8712f_wdt_notify,
225 static ssize_t
226 it8712f_wdt_write(struct file *file, const char __user *data,
227 size_t len, loff_t *ppos)
229 /* check for a magic close character */
230 if (len) {
231 size_t i;
233 it8712f_wdt_ping();
235 expect_close = 0;
236 for (i = 0; i < len; ++i) {
237 char c;
238 if (get_user(c, data+i))
239 return -EFAULT;
240 if (c == 'V')
241 expect_close = 42;
245 return len;
248 static int
249 it8712f_wdt_ioctl(struct inode *inode, struct file *file,
250 unsigned int cmd, unsigned long arg)
252 void __user *argp = (void __user *)arg;
253 int __user *p = argp;
254 static struct watchdog_info ident = {
255 .identity = "IT8712F Watchdog",
256 .firmware_version = 1,
257 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
259 int value;
261 switch (cmd) {
262 default:
263 return -ENOTTY;
264 case WDIOC_GETSUPPORT:
265 if (copy_to_user(argp, &ident, sizeof(ident)))
266 return -EFAULT;
267 return 0;
268 case WDIOC_GETSTATUS:
269 superio_enter();
270 superio_select(LDN_GPIO);
272 value = it8712f_wdt_get_status();
274 superio_exit();
276 return put_user(value, p);
277 case WDIOC_GETBOOTSTATUS:
278 return put_user(0, p);
279 case WDIOC_KEEPALIVE:
280 it8712f_wdt_ping();
281 return 0;
282 case WDIOC_SETTIMEOUT:
283 if (get_user(value, p))
284 return -EFAULT;
285 if (value < 1)
286 return -EINVAL;
287 if (value > (max_units * 60))
288 return -EINVAL;
289 margin = value;
290 superio_enter();
291 superio_select(LDN_GPIO);
293 it8712f_wdt_update_margin();
295 superio_exit();
296 it8712f_wdt_ping();
297 /* Fall through */
298 case WDIOC_GETTIMEOUT:
299 if (put_user(margin, p))
300 return -EFAULT;
301 return 0;
305 static int
306 it8712f_wdt_open(struct inode *inode, struct file *file)
308 /* only allow one at a time */
309 if (down_trylock(&it8712f_wdt_sem))
310 return -EBUSY;
311 it8712f_wdt_enable();
313 return nonseekable_open(inode, file);
316 static int
317 it8712f_wdt_release(struct inode *inode, struct file *file)
319 if (expect_close != 42) {
320 printk(KERN_WARNING NAME
321 ": watchdog device closed unexpectedly, will not"
322 " disable the watchdog timer\n");
323 } else if (!nowayout) {
324 it8712f_wdt_disable();
326 expect_close = 0;
327 up(&it8712f_wdt_sem);
329 return 0;
332 static const struct file_operations it8712f_wdt_fops = {
333 .owner = THIS_MODULE,
334 .llseek = no_llseek,
335 .write = it8712f_wdt_write,
336 .ioctl = it8712f_wdt_ioctl,
337 .open = it8712f_wdt_open,
338 .release = it8712f_wdt_release,
341 static struct miscdevice it8712f_wdt_miscdev = {
342 .minor = WATCHDOG_MINOR,
343 .name = "watchdog",
344 .fops = &it8712f_wdt_fops,
347 static int __init
348 it8712f_wdt_find(unsigned short *address)
350 int err = -ENODEV;
351 int chip_type;
353 superio_enter();
354 chip_type = superio_inw(DEVID);
355 if (chip_type != IT8712F_DEVID)
356 goto exit;
358 superio_select(LDN_GAME);
359 superio_outb(1, ACT_REG);
360 if (!(superio_inb(ACT_REG) & 0x01)) {
361 printk(KERN_ERR NAME ": Device not activated, skipping\n");
362 goto exit;
365 *address = superio_inw(BASE_REG);
366 if (*address == 0) {
367 printk(KERN_ERR NAME ": Base address not set, skipping\n");
368 goto exit;
371 err = 0;
372 revision = superio_inb(DEVREV) & 0x0f;
374 /* Later revisions have 16-bit values per datasheet 0.9.1 */
375 if (revision >= 0x08)
376 max_units = 65535;
378 if (margin > (max_units * 60))
379 margin = (max_units * 60);
381 printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
382 "using DogFood address 0x%x\n",
383 chip_type, revision, *address);
385 exit:
386 superio_exit();
387 return err;
390 static int __init
391 it8712f_wdt_init(void)
393 int err = 0;
395 spin_lock_init(&io_lock);
397 if (it8712f_wdt_find(&address))
398 return -ENODEV;
400 if (!request_region(address, 1, "IT8712F Watchdog")) {
401 printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
402 return -EBUSY;
405 it8712f_wdt_disable();
407 sema_init(&it8712f_wdt_sem, 1);
409 err = register_reboot_notifier(&it8712f_wdt_notifier);
410 if (err) {
411 printk(KERN_ERR NAME ": unable to register reboot notifier\n");
412 goto out;
415 err = misc_register(&it8712f_wdt_miscdev);
416 if (err) {
417 printk(KERN_ERR NAME
418 ": cannot register miscdev on minor=%d (err=%d)\n",
419 WATCHDOG_MINOR, err);
420 goto reboot_out;
423 return 0;
426 reboot_out:
427 unregister_reboot_notifier(&it8712f_wdt_notifier);
428 out:
429 release_region(address, 1);
430 return err;
433 static void __exit
434 it8712f_wdt_exit(void)
436 misc_deregister(&it8712f_wdt_miscdev);
437 unregister_reboot_notifier(&it8712f_wdt_notifier);
438 release_region(address, 1);
441 module_init(it8712f_wdt_init);
442 module_exit(it8712f_wdt_exit);