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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
Joe Perches27c766a2012-02-15 15:06:19 -080010#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/types.h>
15#include <linux/miscdevice.h>
16#include <linux/watchdog.h>
17#include <linux/ioport.h>
18#include <linux/notifier.h>
19#include <linux/reboot.h>
20#include <linux/init.h>
21#include <linux/fs.h>
22#include <linux/pci.h>
Alan Cox173d95b2008-05-19 14:04:57 +010023#include <linux/uaccess.h>
24#include <linux/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26#define WATCHDOG_NAME "ALi_M1535"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
28
29/* internal variables */
30static unsigned long ali_is_open;
31static char ali_expect_release;
32static struct pci_dev *ali_pci;
Alan Cox173d95b2008-05-19 14:04:57 +010033static u32 ali_timeout_bits; /* stores the computed timeout */
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070034static DEFINE_SPINLOCK(ali_lock); /* Guards the hardware */
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36/* module parameters */
37static int timeout = WATCHDOG_TIMEOUT;
38module_param(timeout, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010039MODULE_PARM_DESC(timeout,
40 "Watchdog timeout in seconds. (0 < timeout < 18000, default="
41 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010043static bool nowayout = WATCHDOG_NOWAYOUT;
44module_param(nowayout, bool, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010045MODULE_PARM_DESC(nowayout,
46 "Watchdog cannot be stopped once started (default="
47 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49/*
50 * ali_start - start watchdog countdown
51 *
52 * Starts the timer running providing the timer has a counter
53 * configuration set.
54 */
55
56static void ali_start(void)
57{
58 u32 val;
59
60 spin_lock(&ali_lock);
61
62 pci_read_config_dword(ali_pci, 0xCC, &val);
63 val &= ~0x3F; /* Mask count */
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000064 val |= (1 << 25) | ali_timeout_bits;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 pci_write_config_dword(ali_pci, 0xCC, val);
66
67 spin_unlock(&ali_lock);
68}
69
70/*
71 * ali_stop - stop the timer countdown
72 *
73 * Stop the ALi watchdog countdown
74 */
75
76static void ali_stop(void)
77{
78 u32 val;
79
80 spin_lock(&ali_lock);
81
82 pci_read_config_dword(ali_pci, 0xCC, &val);
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000083 val &= ~0x3F; /* Mask count to zero (disabled) */
84 val &= ~(1 << 25); /* and for safety mask the reset enable */
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 pci_write_config_dword(ali_pci, 0xCC, val);
86
87 spin_unlock(&ali_lock);
88}
89
90/*
91 * ali_keepalive - send a keepalive to the watchdog
92 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000093 * Send a keepalive to the timer (actually we restart the timer).
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 */
95
96static void ali_keepalive(void)
97{
98 ali_start();
99}
100
101/*
102 * ali_settimer - compute the timer reload value
103 * @t: time in seconds
104 *
105 * Computes the timeout values needed
106 */
107
108static int ali_settimer(int t)
109{
Alan Cox173d95b2008-05-19 14:04:57 +0100110 if (t < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 return -EINVAL;
Alan Cox173d95b2008-05-19 14:04:57 +0100112 else if (t < 60)
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000113 ali_timeout_bits = t|(1 << 6);
Alan Cox173d95b2008-05-19 14:04:57 +0100114 else if (t < 3600)
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000115 ali_timeout_bits = (t / 60)|(1 << 7);
Alan Cox173d95b2008-05-19 14:04:57 +0100116 else if (t < 18000)
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000117 ali_timeout_bits = (t / 300)|(1 << 6)|(1 << 7);
Alan Cox173d95b2008-05-19 14:04:57 +0100118 else
119 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
121 timeout = t;
122 return 0;
123}
124
125/*
126 * /dev/watchdog handling
127 */
128
129/*
130 * ali_write - writes to ALi watchdog
131 * @file: file from VFS
132 * @data: user address of data
133 * @len: length of data
134 * @ppos: pointer to the file offset
135 *
136 * Handle a write to the ALi watchdog. Writing to the file pings
137 * the watchdog and resets it. Writing the magic 'V' sequence allows
138 * the next close to turn off the watchdog.
139 */
140
141static ssize_t ali_write(struct file *file, const char __user *data,
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000142 size_t len, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 /* See if we got the magic character 'V' and reload the timer */
145 if (len) {
146 if (!nowayout) {
147 size_t i;
148
Alan Cox173d95b2008-05-19 14:04:57 +0100149 /* note: just in case someone wrote the
150 magic character five months ago... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 ali_expect_release = 0;
152
Alan Cox173d95b2008-05-19 14:04:57 +0100153 /* scan to see whether or not we got
154 the magic character */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 for (i = 0; i != len; i++) {
156 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000157 if (get_user(c, data + i))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 return -EFAULT;
159 if (c == 'V')
160 ali_expect_release = 42;
161 }
162 }
163
164 /* someone wrote to us, we should reload the timer */
165 ali_start();
166 }
167 return len;
168}
169
170/*
171 * ali_ioctl - handle watchdog ioctls
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 * @file: VFS file pointer
173 * @cmd: ioctl number
174 * @arg: arguments to the ioctl
175 *
176 * Handle the watchdog ioctls supported by the ALi driver. Really
177 * we want an extension to enable irq ack monitoring and the like
178 */
179
Alan Cox173d95b2008-05-19 14:04:57 +0100180static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
182 void __user *argp = (void __user *)arg;
183 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000184 static const struct watchdog_info ident = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 .options = WDIOF_KEEPALIVEPING |
186 WDIOF_SETTIMEOUT |
187 WDIOF_MAGICCLOSE,
188 .firmware_version = 0,
189 .identity = "ALi M1535 WatchDog Timer",
190 };
191
192 switch (cmd) {
Alan Cox173d95b2008-05-19 14:04:57 +0100193 case WDIOC_GETSUPPORT:
194 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Alan Cox173d95b2008-05-19 14:04:57 +0100196 case WDIOC_GETSTATUS:
197 case WDIOC_GETBOOTSTATUS:
198 return put_user(0, p);
Alan Cox173d95b2008-05-19 14:04:57 +0100199 case WDIOC_SETOPTIONS:
200 {
201 int new_options, retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
Alan Cox173d95b2008-05-19 14:04:57 +0100203 if (get_user(new_options, p))
204 return -EFAULT;
205 if (new_options & WDIOS_DISABLECARD) {
206 ali_stop();
207 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 }
Alan Cox173d95b2008-05-19 14:04:57 +0100209 if (new_options & WDIOS_ENABLECARD) {
210 ali_start();
211 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 }
Alan Cox173d95b2008-05-19 14:04:57 +0100213 return retval;
214 }
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000215 case WDIOC_KEEPALIVE:
216 ali_keepalive();
217 return 0;
Alan Cox173d95b2008-05-19 14:04:57 +0100218 case WDIOC_SETTIMEOUT:
219 {
220 int new_timeout;
221 if (get_user(new_timeout, p))
222 return -EFAULT;
223 if (ali_settimer(new_timeout))
224 return -EINVAL;
225 ali_keepalive();
226 /* Fall */
227 }
228 case WDIOC_GETTIMEOUT:
229 return put_user(timeout, p);
230 default:
231 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 }
233}
234
235/*
236 * ali_open - handle open of ali watchdog
237 * @inode: inode from VFS
238 * @file: file from VFS
239 *
240 * Open the ALi watchdog device. Ensure only one person opens it
241 * at a time. Also start the watchdog running.
242 */
243
244static int ali_open(struct inode *inode, struct file *file)
245{
246 /* /dev/watchdog can only be opened once */
247 if (test_and_set_bit(0, &ali_is_open))
248 return -EBUSY;
249
250 /* Activate */
251 ali_start();
252 return nonseekable_open(inode, file);
253}
254
255/*
256 * ali_release - close an ALi watchdog
257 * @inode: inode from VFS
258 * @file: file from VFS
259 *
260 * Close the ALi watchdog device. Actual shutdown of the timer
261 * only occurs if the magic sequence has been set.
262 */
263
264static int ali_release(struct inode *inode, struct file *file)
265{
266 /*
267 * Shut off the timer.
268 */
Alan Cox173d95b2008-05-19 14:04:57 +0100269 if (ali_expect_release == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 ali_stop();
Alan Cox173d95b2008-05-19 14:04:57 +0100271 else {
Joe Perches27c766a2012-02-15 15:06:19 -0800272 pr_crit("Unexpected close, not stopping watchdog!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 ali_keepalive();
274 }
275 clear_bit(0, &ali_is_open);
276 ali_expect_release = 0;
277 return 0;
278}
279
280/*
281 * ali_notify_sys - System down notifier
282 *
283 * Notifier for system down
284 */
285
286
Alan Cox173d95b2008-05-19 14:04:57 +0100287static int ali_notify_sys(struct notifier_block *this,
288 unsigned long code, void *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
Alan Cox173d95b2008-05-19 14:04:57 +0100290 if (code == SYS_DOWN || code == SYS_HALT)
291 ali_stop(); /* Turn the WDT off */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 return NOTIFY_DONE;
293}
294
295/*
296 * Data for PCI driver interface
297 *
298 * This data only exists for exporting the supported
299 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
300 * register a pci_driver, because someone else might one day
301 * want to register another driver on the same PCI id.
302 */
303
Wim Van Sebroeck4562f532011-02-21 12:16:44 +0000304static DEFINE_PCI_DEVICE_TABLE(ali_pci_tbl) __used = {
Andrey Borzenkov6e420b72007-08-16 19:32:19 +0000305 { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
Rolf Eike Beerb7343f02005-07-27 11:43:42 -0700306 { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 { 0, },
308};
309MODULE_DEVICE_TABLE(pci, ali_pci_tbl);
310
311/*
312 * ali_find_watchdog - find a 1535 and 7101
313 *
314 * Scans the PCI hardware for a 1535 series bridge and matching 7101
315 * watchdog device. This may be overtight but it is better to be safe
316 */
317
318static int __init ali_find_watchdog(void)
319{
320 struct pci_dev *pdev;
321 u32 wdog;
322
Andrey Borzenkov6e420b72007-08-16 19:32:19 +0000323 /* Check for a 1533/1535 series bridge */
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159324 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
Andrey Borzenkov6e420b72007-08-16 19:32:19 +0000325 if (pdev == NULL)
326 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
327 if (pdev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 return -ENODEV;
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159329 pci_dev_put(pdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
331 /* Check for the a 7101 PMU */
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159332 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
Alan Cox173d95b2008-05-19 14:04:57 +0100333 if (pdev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return -ENODEV;
335
Alan Cox173d95b2008-05-19 14:04:57 +0100336 if (pci_enable_device(pdev)) {
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159337 pci_dev_put(pdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return -EIO;
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159339 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341 ali_pci = pdev;
342
343 /*
344 * Initialize the timer bits
345 */
346 pci_read_config_dword(pdev, 0xCC, &wdog);
347
Alan Cox173d95b2008-05-19 14:04:57 +0100348 /* Timer bits */
349 wdog &= ~0x3F;
350 /* Issued events */
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000351 wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
Alan Cox173d95b2008-05-19 14:04:57 +0100352 /* No monitor bits */
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000353 wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
355 pci_write_config_dword(pdev, 0xCC, wdog);
356
357 return 0;
358}
359
360/*
361 * Kernel Interfaces
362 */
363
Arjan van de Ven62322d22006-07-03 00:24:21 -0700364static const struct file_operations ali_fops = {
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000365 .owner = THIS_MODULE,
366 .llseek = no_llseek,
Alan Cox173d95b2008-05-19 14:04:57 +0100367 .write = ali_write,
368 .unlocked_ioctl = ali_ioctl,
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000369 .open = ali_open,
370 .release = ali_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371};
372
373static struct miscdevice ali_miscdev = {
374 .minor = WATCHDOG_MINOR,
375 .name = "watchdog",
376 .fops = &ali_fops,
377};
378
379static struct notifier_block ali_notifier = {
380 .notifier_call = ali_notify_sys,
381};
382
383/*
384 * watchdog_init - module initialiser
385 *
386 * Scan for a suitable watchdog and if so initialize it. Return an error
387 * if we cannot, the error causes the module to unload
388 */
389
390static int __init watchdog_init(void)
391{
392 int ret;
393
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 /* Check whether or not the hardware watchdog is there */
Alan Cox173d95b2008-05-19 14:04:57 +0100395 if (ali_find_watchdog() != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
Alan Cox173d95b2008-05-19 14:04:57 +0100398 /* Check that the timeout value is within it's range;
399 if not reset to the default */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 if (timeout < 1 || timeout >= 18000) {
401 timeout = WATCHDOG_TIMEOUT;
Joe Perches27c766a2012-02-15 15:06:19 -0800402 pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
403 timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 }
405
406 /* Calculate the watchdog's timeout */
407 ali_settimer(timeout);
408
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 ret = register_reboot_notifier(&ali_notifier);
410 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800411 pr_err("cannot register reboot notifier (err=%d)\n", ret);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000412 goto out;
413 }
414
415 ret = misc_register(&ali_miscdev);
416 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800417 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
418 WATCHDOG_MINOR, ret);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000419 goto unreg_reboot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 }
421
Joe Perches27c766a2012-02-15 15:06:19 -0800422 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 timeout, nowayout);
424
425out:
426 return ret;
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000427unreg_reboot:
428 unregister_reboot_notifier(&ali_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 goto out;
430}
431
432/*
433 * watchdog_exit - module de-initialiser
434 *
435 * Called while unloading a successfully installed watchdog module.
436 */
437
438static void __exit watchdog_exit(void)
439{
440 /* Stop the timer before we leave */
441 ali_stop();
442
443 /* Deregister */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 misc_deregister(&ali_miscdev);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000445 unregister_reboot_notifier(&ali_notifier);
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159446 pci_dev_put(ali_pci);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447}
448
449module_init(watchdog_init);
450module_exit(watchdog_exit);
451
452MODULE_AUTHOR("Alan Cox");
453MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
454MODULE_LICENSE("GPL");