Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets | |
1da177e4 LT |
4 | */ |
5 | ||
27c766aa JP |
6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7 | ||
1da177e4 LT |
8 | #include <linux/module.h> |
9 | #include <linux/moduleparam.h> | |
10 | #include <linux/types.h> | |
11 | #include <linux/miscdevice.h> | |
12 | #include <linux/watchdog.h> | |
13 | #include <linux/ioport.h> | |
14 | #include <linux/notifier.h> | |
15 | #include <linux/reboot.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/pci.h> | |
173d95bc AC |
19 | #include <linux/uaccess.h> |
20 | #include <linux/io.h> | |
1da177e4 LT |
21 | |
22 | #define WATCHDOG_NAME "ALi_M1535" | |
1da177e4 LT |
23 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ |
24 | ||
25 | /* internal variables */ | |
26 | static unsigned long ali_is_open; | |
27 | static char ali_expect_release; | |
28 | static struct pci_dev *ali_pci; | |
173d95bc | 29 | static u32 ali_timeout_bits; /* stores the computed timeout */ |
c7dfd0cc | 30 | static DEFINE_SPINLOCK(ali_lock); /* Guards the hardware */ |
1da177e4 LT |
31 | |
32 | /* module parameters */ | |
33 | static int timeout = WATCHDOG_TIMEOUT; | |
34 | module_param(timeout, int, 0); | |
173d95bc AC |
35 | MODULE_PARM_DESC(timeout, |
36 | "Watchdog timeout in seconds. (0 < timeout < 18000, default=" | |
37 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
1da177e4 | 38 | |
86a1e189 WVS |
39 | static bool nowayout = WATCHDOG_NOWAYOUT; |
40 | module_param(nowayout, bool, 0); | |
173d95bc AC |
41 | MODULE_PARM_DESC(nowayout, |
42 | "Watchdog cannot be stopped once started (default=" | |
43 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
44 | |
45 | /* | |
46 | * ali_start - start watchdog countdown | |
47 | * | |
48 | * Starts the timer running providing the timer has a counter | |
49 | * configuration set. | |
50 | */ | |
51 | ||
52 | static void ali_start(void) | |
53 | { | |
54 | u32 val; | |
55 | ||
56 | spin_lock(&ali_lock); | |
57 | ||
58 | pci_read_config_dword(ali_pci, 0xCC, &val); | |
59 | val &= ~0x3F; /* Mask count */ | |
143a2e54 | 60 | val |= (1 << 25) | ali_timeout_bits; |
1da177e4 LT |
61 | pci_write_config_dword(ali_pci, 0xCC, val); |
62 | ||
63 | spin_unlock(&ali_lock); | |
64 | } | |
65 | ||
66 | /* | |
67 | * ali_stop - stop the timer countdown | |
68 | * | |
69 | * Stop the ALi watchdog countdown | |
70 | */ | |
71 | ||
72 | static void ali_stop(void) | |
73 | { | |
74 | u32 val; | |
75 | ||
76 | spin_lock(&ali_lock); | |
77 | ||
78 | pci_read_config_dword(ali_pci, 0xCC, &val); | |
143a2e54 WVS |
79 | val &= ~0x3F; /* Mask count to zero (disabled) */ |
80 | val &= ~(1 << 25); /* and for safety mask the reset enable */ | |
1da177e4 LT |
81 | pci_write_config_dword(ali_pci, 0xCC, val); |
82 | ||
83 | spin_unlock(&ali_lock); | |
84 | } | |
85 | ||
86 | /* | |
87 | * ali_keepalive - send a keepalive to the watchdog | |
88 | * | |
143a2e54 | 89 | * Send a keepalive to the timer (actually we restart the timer). |
1da177e4 LT |
90 | */ |
91 | ||
92 | static void ali_keepalive(void) | |
93 | { | |
94 | ali_start(); | |
95 | } | |
96 | ||
97 | /* | |
98 | * ali_settimer - compute the timer reload value | |
99 | * @t: time in seconds | |
100 | * | |
101 | * Computes the timeout values needed | |
102 | */ | |
103 | ||
104 | static int ali_settimer(int t) | |
105 | { | |
173d95bc | 106 | if (t < 0) |
1da177e4 | 107 | return -EINVAL; |
173d95bc | 108 | else if (t < 60) |
143a2e54 | 109 | ali_timeout_bits = t|(1 << 6); |
173d95bc | 110 | else if (t < 3600) |
143a2e54 | 111 | ali_timeout_bits = (t / 60)|(1 << 7); |
173d95bc | 112 | else if (t < 18000) |
143a2e54 | 113 | ali_timeout_bits = (t / 300)|(1 << 6)|(1 << 7); |
173d95bc AC |
114 | else |
115 | return -EINVAL; | |
1da177e4 LT |
116 | |
117 | timeout = t; | |
118 | return 0; | |
119 | } | |
120 | ||
121 | /* | |
122 | * /dev/watchdog handling | |
123 | */ | |
124 | ||
125 | /* | |
126 | * ali_write - writes to ALi watchdog | |
127 | * @file: file from VFS | |
128 | * @data: user address of data | |
129 | * @len: length of data | |
130 | * @ppos: pointer to the file offset | |
131 | * | |
132 | * Handle a write to the ALi watchdog. Writing to the file pings | |
133 | * the watchdog and resets it. Writing the magic 'V' sequence allows | |
134 | * the next close to turn off the watchdog. | |
135 | */ | |
136 | ||
137 | static ssize_t ali_write(struct file *file, const char __user *data, | |
143a2e54 | 138 | size_t len, loff_t *ppos) |
1da177e4 LT |
139 | { |
140 | /* See if we got the magic character 'V' and reload the timer */ | |
141 | if (len) { | |
142 | if (!nowayout) { | |
143 | size_t i; | |
144 | ||
173d95bc AC |
145 | /* note: just in case someone wrote the |
146 | magic character five months ago... */ | |
1da177e4 LT |
147 | ali_expect_release = 0; |
148 | ||
173d95bc AC |
149 | /* scan to see whether or not we got |
150 | the magic character */ | |
1da177e4 LT |
151 | for (i = 0; i != len; i++) { |
152 | char c; | |
7944d3a5 | 153 | if (get_user(c, data + i)) |
1da177e4 LT |
154 | return -EFAULT; |
155 | if (c == 'V') | |
156 | ali_expect_release = 42; | |
157 | } | |
158 | } | |
159 | ||
160 | /* someone wrote to us, we should reload the timer */ | |
161 | ali_start(); | |
162 | } | |
163 | return len; | |
164 | } | |
165 | ||
166 | /* | |
167 | * ali_ioctl - handle watchdog ioctls | |
1da177e4 LT |
168 | * @file: VFS file pointer |
169 | * @cmd: ioctl number | |
170 | * @arg: arguments to the ioctl | |
171 | * | |
172 | * Handle the watchdog ioctls supported by the ALi driver. Really | |
173 | * we want an extension to enable irq ack monitoring and the like | |
174 | */ | |
175 | ||
173d95bc | 176 | static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
177 | { |
178 | void __user *argp = (void __user *)arg; | |
179 | int __user *p = argp; | |
42747d71 | 180 | static const struct watchdog_info ident = { |
1da177e4 LT |
181 | .options = WDIOF_KEEPALIVEPING | |
182 | WDIOF_SETTIMEOUT | | |
183 | WDIOF_MAGICCLOSE, | |
184 | .firmware_version = 0, | |
185 | .identity = "ALi M1535 WatchDog Timer", | |
186 | }; | |
187 | ||
188 | switch (cmd) { | |
173d95bc AC |
189 | case WDIOC_GETSUPPORT: |
190 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
1da177e4 | 191 | |
173d95bc AC |
192 | case WDIOC_GETSTATUS: |
193 | case WDIOC_GETBOOTSTATUS: | |
194 | return put_user(0, p); | |
173d95bc AC |
195 | case WDIOC_SETOPTIONS: |
196 | { | |
197 | int new_options, retval = -EINVAL; | |
198 | ||
199 | if (get_user(new_options, p)) | |
200 | return -EFAULT; | |
201 | if (new_options & WDIOS_DISABLECARD) { | |
202 | ali_stop(); | |
203 | retval = 0; | |
1da177e4 | 204 | } |
173d95bc AC |
205 | if (new_options & WDIOS_ENABLECARD) { |
206 | ali_start(); | |
207 | retval = 0; | |
1da177e4 | 208 | } |
173d95bc AC |
209 | return retval; |
210 | } | |
0c06090c WVS |
211 | case WDIOC_KEEPALIVE: |
212 | ali_keepalive(); | |
213 | return 0; | |
173d95bc AC |
214 | case WDIOC_SETTIMEOUT: |
215 | { | |
216 | int new_timeout; | |
217 | if (get_user(new_timeout, p)) | |
218 | return -EFAULT; | |
219 | if (ali_settimer(new_timeout)) | |
220 | return -EINVAL; | |
221 | ali_keepalive(); | |
173d95bc | 222 | } |
bd490f82 | 223 | fallthrough; |
173d95bc AC |
224 | case WDIOC_GETTIMEOUT: |
225 | return put_user(timeout, p); | |
226 | default: | |
227 | return -ENOTTY; | |
1da177e4 LT |
228 | } |
229 | } | |
230 | ||
231 | /* | |
232 | * ali_open - handle open of ali watchdog | |
233 | * @inode: inode from VFS | |
234 | * @file: file from VFS | |
235 | * | |
236 | * Open the ALi watchdog device. Ensure only one person opens it | |
237 | * at a time. Also start the watchdog running. | |
238 | */ | |
239 | ||
240 | static int ali_open(struct inode *inode, struct file *file) | |
241 | { | |
242 | /* /dev/watchdog can only be opened once */ | |
243 | if (test_and_set_bit(0, &ali_is_open)) | |
244 | return -EBUSY; | |
245 | ||
246 | /* Activate */ | |
247 | ali_start(); | |
c5bf68fe | 248 | return stream_open(inode, file); |
1da177e4 LT |
249 | } |
250 | ||
251 | /* | |
252 | * ali_release - close an ALi watchdog | |
253 | * @inode: inode from VFS | |
254 | * @file: file from VFS | |
255 | * | |
256 | * Close the ALi watchdog device. Actual shutdown of the timer | |
257 | * only occurs if the magic sequence has been set. | |
258 | */ | |
259 | ||
260 | static int ali_release(struct inode *inode, struct file *file) | |
261 | { | |
262 | /* | |
263 | * Shut off the timer. | |
264 | */ | |
173d95bc | 265 | if (ali_expect_release == 42) |
1da177e4 | 266 | ali_stop(); |
173d95bc | 267 | else { |
27c766aa | 268 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
1da177e4 LT |
269 | ali_keepalive(); |
270 | } | |
271 | clear_bit(0, &ali_is_open); | |
272 | ali_expect_release = 0; | |
273 | return 0; | |
274 | } | |
275 | ||
276 | /* | |
277 | * ali_notify_sys - System down notifier | |
278 | * | |
279 | * Notifier for system down | |
280 | */ | |
281 | ||
282 | ||
173d95bc AC |
283 | static int ali_notify_sys(struct notifier_block *this, |
284 | unsigned long code, void *unused) | |
1da177e4 | 285 | { |
173d95bc AC |
286 | if (code == SYS_DOWN || code == SYS_HALT) |
287 | ali_stop(); /* Turn the WDT off */ | |
1da177e4 LT |
288 | return NOTIFY_DONE; |
289 | } | |
290 | ||
291 | /* | |
292 | * Data for PCI driver interface | |
293 | * | |
294 | * This data only exists for exporting the supported | |
295 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | |
296 | * register a pci_driver, because someone else might one day | |
297 | * want to register another driver on the same PCI id. | |
298 | */ | |
299 | ||
bc17f9dc | 300 | static const struct pci_device_id ali_pci_tbl[] __used = { |
6e420b7e | 301 | { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,}, |
b7343f01 | 302 | { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,}, |
1da177e4 LT |
303 | { 0, }, |
304 | }; | |
305 | MODULE_DEVICE_TABLE(pci, ali_pci_tbl); | |
306 | ||
307 | /* | |
308 | * ali_find_watchdog - find a 1535 and 7101 | |
309 | * | |
310 | * Scans the PCI hardware for a 1535 series bridge and matching 7101 | |
311 | * watchdog device. This may be overtight but it is better to be safe | |
312 | */ | |
313 | ||
314 | static int __init ali_find_watchdog(void) | |
315 | { | |
316 | struct pci_dev *pdev; | |
317 | u32 wdog; | |
318 | ||
6e420b7e | 319 | /* Check for a 1533/1535 series bridge */ |
02be2ee9 | 320 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL); |
6e420b7e AB |
321 | if (pdev == NULL) |
322 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL); | |
323 | if (pdev == NULL) | |
1da177e4 | 324 | return -ENODEV; |
02be2ee9 | 325 | pci_dev_put(pdev); |
1da177e4 LT |
326 | |
327 | /* Check for the a 7101 PMU */ | |
02be2ee9 | 328 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL); |
173d95bc | 329 | if (pdev == NULL) |
1da177e4 LT |
330 | return -ENODEV; |
331 | ||
173d95bc | 332 | if (pci_enable_device(pdev)) { |
02be2ee9 | 333 | pci_dev_put(pdev); |
1da177e4 | 334 | return -EIO; |
02be2ee9 | 335 | } |
1da177e4 LT |
336 | |
337 | ali_pci = pdev; | |
338 | ||
339 | /* | |
340 | * Initialize the timer bits | |
341 | */ | |
342 | pci_read_config_dword(pdev, 0xCC, &wdog); | |
343 | ||
173d95bc AC |
344 | /* Timer bits */ |
345 | wdog &= ~0x3F; | |
346 | /* Issued events */ | |
143a2e54 | 347 | wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24)); |
173d95bc | 348 | /* No monitor bits */ |
143a2e54 | 349 | wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9)); |
1da177e4 LT |
350 | |
351 | pci_write_config_dword(pdev, 0xCC, wdog); | |
352 | ||
353 | return 0; | |
354 | } | |
355 | ||
356 | /* | |
357 | * Kernel Interfaces | |
358 | */ | |
359 | ||
62322d25 | 360 | static const struct file_operations ali_fops = { |
5f3b2756 WVS |
361 | .owner = THIS_MODULE, |
362 | .llseek = no_llseek, | |
173d95bc AC |
363 | .write = ali_write, |
364 | .unlocked_ioctl = ali_ioctl, | |
b6dfb247 | 365 | .compat_ioctl = compat_ptr_ioctl, |
5f3b2756 WVS |
366 | .open = ali_open, |
367 | .release = ali_release, | |
1da177e4 LT |
368 | }; |
369 | ||
370 | static struct miscdevice ali_miscdev = { | |
371 | .minor = WATCHDOG_MINOR, | |
372 | .name = "watchdog", | |
373 | .fops = &ali_fops, | |
374 | }; | |
375 | ||
376 | static struct notifier_block ali_notifier = { | |
377 | .notifier_call = ali_notify_sys, | |
378 | }; | |
379 | ||
380 | /* | |
381 | * watchdog_init - module initialiser | |
382 | * | |
383 | * Scan for a suitable watchdog and if so initialize it. Return an error | |
384 | * if we cannot, the error causes the module to unload | |
385 | */ | |
386 | ||
387 | static int __init watchdog_init(void) | |
388 | { | |
389 | int ret; | |
390 | ||
1da177e4 | 391 | /* Check whether or not the hardware watchdog is there */ |
173d95bc | 392 | if (ali_find_watchdog() != 0) |
1da177e4 | 393 | return -ENODEV; |
1da177e4 | 394 | |
173d95bc AC |
395 | /* Check that the timeout value is within it's range; |
396 | if not reset to the default */ | |
1da177e4 LT |
397 | if (timeout < 1 || timeout >= 18000) { |
398 | timeout = WATCHDOG_TIMEOUT; | |
27c766aa JP |
399 | pr_info("timeout value must be 0 < timeout < 18000, using %d\n", |
400 | timeout); | |
1da177e4 LT |
401 | } |
402 | ||
403 | /* Calculate the watchdog's timeout */ | |
404 | ali_settimer(timeout); | |
405 | ||
c6cb13ae | 406 | ret = register_reboot_notifier(&ali_notifier); |
1da177e4 | 407 | if (ret != 0) { |
27c766aa | 408 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
409 | goto out; |
410 | } | |
411 | ||
c6cb13ae | 412 | ret = misc_register(&ali_miscdev); |
1da177e4 | 413 | if (ret != 0) { |
27c766aa JP |
414 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
415 | WATCHDOG_MINOR, ret); | |
c6cb13ae | 416 | goto unreg_reboot; |
1da177e4 LT |
417 | } |
418 | ||
27c766aa | 419 | pr_info("initialized. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
420 | timeout, nowayout); |
421 | ||
422 | out: | |
423 | return ret; | |
c6cb13ae WVS |
424 | unreg_reboot: |
425 | unregister_reboot_notifier(&ali_notifier); | |
1da177e4 LT |
426 | goto out; |
427 | } | |
428 | ||
429 | /* | |
430 | * watchdog_exit - module de-initialiser | |
431 | * | |
432 | * Called while unloading a successfully installed watchdog module. | |
433 | */ | |
434 | ||
435 | static void __exit watchdog_exit(void) | |
436 | { | |
437 | /* Stop the timer before we leave */ | |
438 | ali_stop(); | |
439 | ||
440 | /* Deregister */ | |
1da177e4 | 441 | misc_deregister(&ali_miscdev); |
c6cb13ae | 442 | unregister_reboot_notifier(&ali_notifier); |
02be2ee9 | 443 | pci_dev_put(ali_pci); |
1da177e4 LT |
444 | } |
445 | ||
446 | module_init(watchdog_init); | |
447 | module_exit(watchdog_exit); | |
448 | ||
449 | MODULE_AUTHOR("Alan Cox"); | |
450 | MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver"); | |
451 | MODULE_LICENSE("GPL"); |