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456c7301 MW |
1 | /* |
2 | * nv_tco 0.01: TCO timer driver for NV chipsets | |
3 | * | |
4 | * (c) Copyright 2005 Google Inc., All Rights Reserved. | |
5 | * | |
6 | * Based off i8xx_tco.c: | |
7 | * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights | |
8 | * Reserved. | |
9 | * http://www.kernelconcepts.de | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | * | |
16 | * TCO timer driver for NV chipsets | |
17 | * based on softdog.c by Alan Cox <alan@redhat.com> | |
18 | */ | |
19 | ||
20 | /* | |
21 | * Includes, defines, variables, module parameters, ... | |
22 | */ | |
23 | ||
27c766aa JP |
24 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
25 | ||
456c7301 MW |
26 | #include <linux/module.h> |
27 | #include <linux/moduleparam.h> | |
28 | #include <linux/types.h> | |
29 | #include <linux/miscdevice.h> | |
30 | #include <linux/watchdog.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/fs.h> | |
33 | #include <linux/pci.h> | |
34 | #include <linux/ioport.h> | |
35 | #include <linux/jiffies.h> | |
36 | #include <linux/platform_device.h> | |
37 | #include <linux/uaccess.h> | |
38 | #include <linux/io.h> | |
39 | ||
40 | #include "nv_tco.h" | |
41 | ||
42 | /* Module and version information */ | |
43 | #define TCO_VERSION "0.01" | |
44 | #define TCO_MODULE_NAME "NV_TCO" | |
45 | #define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION | |
456c7301 MW |
46 | |
47 | /* internal variables */ | |
48 | static unsigned int tcobase; | |
49 | static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */ | |
50 | static unsigned long timer_alive; | |
51 | static char tco_expect_close; | |
52 | static struct pci_dev *tco_pci; | |
53 | ||
54 | /* the watchdog platform device */ | |
55 | static struct platform_device *nv_tco_platform_device; | |
56 | ||
57 | /* module parameters */ | |
58 | #define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat (2<heartbeat<39) */ | |
59 | static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ | |
60 | module_param(heartbeat, int, 0); | |
61 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, " | |
62 | "default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); | |
63 | ||
86a1e189 WVS |
64 | static bool nowayout = WATCHDOG_NOWAYOUT; |
65 | module_param(nowayout, bool, 0); | |
456c7301 MW |
66 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started" |
67 | " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
68 | ||
69 | /* | |
70 | * Some TCO specific functions | |
71 | */ | |
72 | static inline unsigned char seconds_to_ticks(int seconds) | |
73 | { | |
74 | /* the internal timer is stored as ticks which decrement | |
75 | * every 0.6 seconds */ | |
76 | return (seconds * 10) / 6; | |
77 | } | |
78 | ||
79 | static void tco_timer_start(void) | |
80 | { | |
81 | u32 val; | |
82 | unsigned long flags; | |
83 | ||
84 | spin_lock_irqsave(&tco_lock, flags); | |
85 | val = inl(TCO_CNT(tcobase)); | |
86 | val &= ~TCO_CNT_TCOHALT; | |
87 | outl(val, TCO_CNT(tcobase)); | |
88 | spin_unlock_irqrestore(&tco_lock, flags); | |
89 | } | |
90 | ||
91 | static void tco_timer_stop(void) | |
92 | { | |
93 | u32 val; | |
94 | unsigned long flags; | |
95 | ||
96 | spin_lock_irqsave(&tco_lock, flags); | |
97 | val = inl(TCO_CNT(tcobase)); | |
98 | val |= TCO_CNT_TCOHALT; | |
99 | outl(val, TCO_CNT(tcobase)); | |
100 | spin_unlock_irqrestore(&tco_lock, flags); | |
101 | } | |
102 | ||
103 | static void tco_timer_keepalive(void) | |
104 | { | |
105 | unsigned long flags; | |
106 | ||
107 | spin_lock_irqsave(&tco_lock, flags); | |
108 | outb(0x01, TCO_RLD(tcobase)); | |
109 | spin_unlock_irqrestore(&tco_lock, flags); | |
110 | } | |
111 | ||
112 | static int tco_timer_set_heartbeat(int t) | |
113 | { | |
114 | int ret = 0; | |
115 | unsigned char tmrval; | |
116 | unsigned long flags; | |
117 | u8 val; | |
118 | ||
119 | /* | |
120 | * note seconds_to_ticks(t) > t, so if t > 0x3f, so is | |
121 | * tmrval=seconds_to_ticks(t). Check that the count in seconds isn't | |
122 | * out of range on it's own (to avoid overflow in tmrval). | |
123 | */ | |
124 | if (t < 0 || t > 0x3f) | |
125 | return -EINVAL; | |
126 | tmrval = seconds_to_ticks(t); | |
127 | ||
128 | /* "Values of 0h-3h are ignored and should not be attempted" */ | |
129 | if (tmrval > 0x3f || tmrval < 0x04) | |
130 | return -EINVAL; | |
131 | ||
132 | /* Write new heartbeat to watchdog */ | |
133 | spin_lock_irqsave(&tco_lock, flags); | |
134 | val = inb(TCO_TMR(tcobase)); | |
135 | val &= 0xc0; | |
136 | val |= tmrval; | |
137 | outb(val, TCO_TMR(tcobase)); | |
138 | val = inb(TCO_TMR(tcobase)); | |
139 | ||
140 | if ((val & 0x3f) != tmrval) | |
141 | ret = -EINVAL; | |
142 | spin_unlock_irqrestore(&tco_lock, flags); | |
143 | ||
144 | if (ret) | |
145 | return ret; | |
146 | ||
147 | heartbeat = t; | |
148 | return 0; | |
149 | } | |
150 | ||
151 | /* | |
152 | * /dev/watchdog handling | |
153 | */ | |
154 | ||
155 | static int nv_tco_open(struct inode *inode, struct file *file) | |
156 | { | |
157 | /* /dev/watchdog can only be opened once */ | |
158 | if (test_and_set_bit(0, &timer_alive)) | |
159 | return -EBUSY; | |
160 | ||
161 | /* Reload and activate timer */ | |
162 | tco_timer_keepalive(); | |
163 | tco_timer_start(); | |
164 | return nonseekable_open(inode, file); | |
165 | } | |
166 | ||
167 | static int nv_tco_release(struct inode *inode, struct file *file) | |
168 | { | |
169 | /* Shut off the timer */ | |
170 | if (tco_expect_close == 42) { | |
171 | tco_timer_stop(); | |
172 | } else { | |
27c766aa | 173 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
456c7301 MW |
174 | tco_timer_keepalive(); |
175 | } | |
176 | clear_bit(0, &timer_alive); | |
177 | tco_expect_close = 0; | |
178 | return 0; | |
179 | } | |
180 | ||
181 | static ssize_t nv_tco_write(struct file *file, const char __user *data, | |
182 | size_t len, loff_t *ppos) | |
183 | { | |
184 | /* See if we got the magic character 'V' and reload the timer */ | |
185 | if (len) { | |
186 | if (!nowayout) { | |
187 | size_t i; | |
188 | ||
189 | /* | |
190 | * note: just in case someone wrote the magic character | |
191 | * five months ago... | |
192 | */ | |
193 | tco_expect_close = 0; | |
194 | ||
195 | /* | |
196 | * scan to see whether or not we got the magic | |
197 | * character | |
198 | */ | |
199 | for (i = 0; i != len; i++) { | |
200 | char c; | |
201 | if (get_user(c, data + i)) | |
202 | return -EFAULT; | |
203 | if (c == 'V') | |
204 | tco_expect_close = 42; | |
205 | } | |
206 | } | |
207 | ||
208 | /* someone wrote to us, we should reload the timer */ | |
209 | tco_timer_keepalive(); | |
210 | } | |
211 | return len; | |
212 | } | |
213 | ||
214 | static long nv_tco_ioctl(struct file *file, unsigned int cmd, | |
215 | unsigned long arg) | |
216 | { | |
217 | int new_options, retval = -EINVAL; | |
218 | int new_heartbeat; | |
219 | void __user *argp = (void __user *)arg; | |
220 | int __user *p = argp; | |
221 | static const struct watchdog_info ident = { | |
222 | .options = WDIOF_SETTIMEOUT | | |
223 | WDIOF_KEEPALIVEPING | | |
224 | WDIOF_MAGICCLOSE, | |
225 | .firmware_version = 0, | |
226 | .identity = TCO_MODULE_NAME, | |
227 | }; | |
228 | ||
229 | switch (cmd) { | |
230 | case WDIOC_GETSUPPORT: | |
231 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
232 | case WDIOC_GETSTATUS: | |
233 | case WDIOC_GETBOOTSTATUS: | |
234 | return put_user(0, p); | |
235 | case WDIOC_SETOPTIONS: | |
236 | if (get_user(new_options, p)) | |
237 | return -EFAULT; | |
238 | if (new_options & WDIOS_DISABLECARD) { | |
239 | tco_timer_stop(); | |
240 | retval = 0; | |
241 | } | |
242 | if (new_options & WDIOS_ENABLECARD) { | |
243 | tco_timer_keepalive(); | |
244 | tco_timer_start(); | |
245 | retval = 0; | |
246 | } | |
247 | return retval; | |
248 | case WDIOC_KEEPALIVE: | |
249 | tco_timer_keepalive(); | |
250 | return 0; | |
251 | case WDIOC_SETTIMEOUT: | |
252 | if (get_user(new_heartbeat, p)) | |
253 | return -EFAULT; | |
254 | if (tco_timer_set_heartbeat(new_heartbeat)) | |
255 | return -EINVAL; | |
256 | tco_timer_keepalive(); | |
257 | /* Fall through */ | |
258 | case WDIOC_GETTIMEOUT: | |
259 | return put_user(heartbeat, p); | |
260 | default: | |
261 | return -ENOTTY; | |
262 | } | |
263 | } | |
264 | ||
265 | /* | |
266 | * Kernel Interfaces | |
267 | */ | |
268 | ||
269 | static const struct file_operations nv_tco_fops = { | |
270 | .owner = THIS_MODULE, | |
271 | .llseek = no_llseek, | |
272 | .write = nv_tco_write, | |
273 | .unlocked_ioctl = nv_tco_ioctl, | |
274 | .open = nv_tco_open, | |
275 | .release = nv_tco_release, | |
276 | }; | |
277 | ||
278 | static struct miscdevice nv_tco_miscdev = { | |
279 | .minor = WATCHDOG_MINOR, | |
280 | .name = "watchdog", | |
281 | .fops = &nv_tco_fops, | |
282 | }; | |
283 | ||
284 | /* | |
285 | * Data for PCI driver interface | |
286 | * | |
287 | * This data only exists for exporting the supported | |
288 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | |
289 | * register a pci_driver, because someone else might one day | |
290 | * want to register another driver on the same PCI id. | |
291 | */ | |
bc17f9dc | 292 | static const struct pci_device_id tco_pci_tbl[] = { |
456c7301 MW |
293 | { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS, |
294 | PCI_ANY_ID, PCI_ANY_ID, }, | |
295 | { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS, | |
296 | PCI_ANY_ID, PCI_ANY_ID, }, | |
64307b48 VD |
297 | { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS, |
298 | PCI_ANY_ID, PCI_ANY_ID, }, | |
456c7301 MW |
299 | { 0, }, /* End of list */ |
300 | }; | |
301 | MODULE_DEVICE_TABLE(pci, tco_pci_tbl); | |
302 | ||
303 | /* | |
304 | * Init & exit routines | |
305 | */ | |
306 | ||
2d991a16 | 307 | static unsigned char nv_tco_getdevice(void) |
456c7301 MW |
308 | { |
309 | struct pci_dev *dev = NULL; | |
310 | u32 val; | |
311 | ||
312 | /* Find the PCI device */ | |
313 | for_each_pci_dev(dev) { | |
314 | if (pci_match_id(tco_pci_tbl, dev) != NULL) { | |
315 | tco_pci = dev; | |
316 | break; | |
317 | } | |
318 | } | |
319 | ||
320 | if (!tco_pci) | |
321 | return 0; | |
322 | ||
323 | /* Find the base io port */ | |
324 | pci_read_config_dword(tco_pci, 0x64, &val); | |
325 | val &= 0xffff; | |
326 | if (val == 0x0001 || val == 0x0000) { | |
327 | /* Something is wrong here, bar isn't setup */ | |
27c766aa | 328 | pr_err("failed to get tcobase address\n"); |
456c7301 MW |
329 | return 0; |
330 | } | |
331 | val &= 0xff00; | |
332 | tcobase = val + 0x40; | |
333 | ||
334 | if (!request_region(tcobase, 0x10, "NV TCO")) { | |
27c766aa | 335 | pr_err("I/O address 0x%04x already in use\n", tcobase); |
456c7301 MW |
336 | return 0; |
337 | } | |
338 | ||
339 | /* Set a reasonable heartbeat before we stop the timer */ | |
340 | tco_timer_set_heartbeat(30); | |
341 | ||
342 | /* | |
343 | * Stop the TCO before we change anything so we don't race with | |
344 | * a zeroed timer. | |
345 | */ | |
346 | tco_timer_keepalive(); | |
347 | tco_timer_stop(); | |
348 | ||
349 | /* Disable SMI caused by TCO */ | |
350 | if (!request_region(MCP51_SMI_EN(tcobase), 4, "NV TCO")) { | |
27c766aa | 351 | pr_err("I/O address 0x%04x already in use\n", |
456c7301 MW |
352 | MCP51_SMI_EN(tcobase)); |
353 | goto out; | |
354 | } | |
355 | val = inl(MCP51_SMI_EN(tcobase)); | |
356 | val &= ~MCP51_SMI_EN_TCO; | |
357 | outl(val, MCP51_SMI_EN(tcobase)); | |
358 | val = inl(MCP51_SMI_EN(tcobase)); | |
359 | release_region(MCP51_SMI_EN(tcobase), 4); | |
360 | if (val & MCP51_SMI_EN_TCO) { | |
27c766aa | 361 | pr_err("Could not disable SMI caused by TCO\n"); |
456c7301 MW |
362 | goto out; |
363 | } | |
364 | ||
365 | /* Check chipset's NO_REBOOT bit */ | |
366 | pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val); | |
367 | val |= MCP51_SMBUS_SETUP_B_TCO_REBOOT; | |
368 | pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val); | |
369 | pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val); | |
370 | if (!(val & MCP51_SMBUS_SETUP_B_TCO_REBOOT)) { | |
27c766aa | 371 | pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware\n"); |
456c7301 MW |
372 | goto out; |
373 | } | |
374 | ||
375 | return 1; | |
376 | out: | |
377 | release_region(tcobase, 0x10); | |
378 | return 0; | |
379 | } | |
380 | ||
2d991a16 | 381 | static int nv_tco_init(struct platform_device *dev) |
456c7301 MW |
382 | { |
383 | int ret; | |
384 | ||
385 | /* Check whether or not the hardware watchdog is there */ | |
386 | if (!nv_tco_getdevice()) | |
387 | return -ENODEV; | |
388 | ||
389 | /* Check to see if last reboot was due to watchdog timeout */ | |
27c766aa JP |
390 | pr_info("Watchdog reboot %sdetected\n", |
391 | inl(TCO_STS(tcobase)) & TCO_STS_TCO2TO_STS ? "" : "not "); | |
456c7301 MW |
392 | |
393 | /* Clear out the old status */ | |
394 | outl(TCO_STS_RESET, TCO_STS(tcobase)); | |
395 | ||
396 | /* | |
397 | * Check that the heartbeat value is within it's range. | |
398 | * If not, reset to the default. | |
399 | */ | |
400 | if (tco_timer_set_heartbeat(heartbeat)) { | |
401 | heartbeat = WATCHDOG_HEARTBEAT; | |
402 | tco_timer_set_heartbeat(heartbeat); | |
27c766aa JP |
403 | pr_info("heartbeat value must be 2<heartbeat<39, using %d\n", |
404 | heartbeat); | |
456c7301 MW |
405 | } |
406 | ||
407 | ret = misc_register(&nv_tco_miscdev); | |
408 | if (ret != 0) { | |
27c766aa JP |
409 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
410 | WATCHDOG_MINOR, ret); | |
456c7301 MW |
411 | goto unreg_region; |
412 | } | |
413 | ||
414 | clear_bit(0, &timer_alive); | |
415 | ||
416 | tco_timer_stop(); | |
417 | ||
27c766aa JP |
418 | pr_info("initialized (0x%04x). heartbeat=%d sec (nowayout=%d)\n", |
419 | tcobase, heartbeat, nowayout); | |
456c7301 MW |
420 | |
421 | return 0; | |
422 | ||
423 | unreg_region: | |
424 | release_region(tcobase, 0x10); | |
425 | return ret; | |
426 | } | |
427 | ||
4b12b896 | 428 | static void nv_tco_cleanup(void) |
456c7301 MW |
429 | { |
430 | u32 val; | |
431 | ||
432 | /* Stop the timer before we leave */ | |
433 | if (!nowayout) | |
434 | tco_timer_stop(); | |
435 | ||
436 | /* Set the NO_REBOOT bit to prevent later reboots, just for sure */ | |
437 | pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val); | |
438 | val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT; | |
439 | pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val); | |
440 | pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val); | |
441 | if (val & MCP51_SMBUS_SETUP_B_TCO_REBOOT) { | |
27c766aa | 442 | pr_crit("Couldn't unset REBOOT bit. Machine may soon reset\n"); |
456c7301 MW |
443 | } |
444 | ||
445 | /* Deregister */ | |
446 | misc_deregister(&nv_tco_miscdev); | |
447 | release_region(tcobase, 0x10); | |
448 | } | |
449 | ||
4b12b896 | 450 | static int nv_tco_remove(struct platform_device *dev) |
456c7301 MW |
451 | { |
452 | if (tcobase) | |
453 | nv_tco_cleanup(); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | ||
458 | static void nv_tco_shutdown(struct platform_device *dev) | |
459 | { | |
6b01d30e MG |
460 | u32 val; |
461 | ||
456c7301 | 462 | tco_timer_stop(); |
6b01d30e MG |
463 | |
464 | /* Some BIOSes fail the POST (once) if the NO_REBOOT flag is not | |
465 | * unset during shutdown. */ | |
466 | pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val); | |
467 | val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT; | |
468 | pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val); | |
456c7301 MW |
469 | } |
470 | ||
471 | static struct platform_driver nv_tco_driver = { | |
472 | .probe = nv_tco_init, | |
82268714 | 473 | .remove = nv_tco_remove, |
456c7301 MW |
474 | .shutdown = nv_tco_shutdown, |
475 | .driver = { | |
456c7301 MW |
476 | .name = TCO_MODULE_NAME, |
477 | }, | |
478 | }; | |
479 | ||
480 | static int __init nv_tco_init_module(void) | |
481 | { | |
482 | int err; | |
483 | ||
27c766aa | 484 | pr_info("NV TCO WatchDog Timer Driver v%s\n", TCO_VERSION); |
456c7301 MW |
485 | |
486 | err = platform_driver_register(&nv_tco_driver); | |
487 | if (err) | |
488 | return err; | |
489 | ||
490 | nv_tco_platform_device = platform_device_register_simple( | |
491 | TCO_MODULE_NAME, -1, NULL, 0); | |
492 | if (IS_ERR(nv_tco_platform_device)) { | |
493 | err = PTR_ERR(nv_tco_platform_device); | |
494 | goto unreg_platform_driver; | |
495 | } | |
496 | ||
497 | return 0; | |
498 | ||
499 | unreg_platform_driver: | |
500 | platform_driver_unregister(&nv_tco_driver); | |
501 | return err; | |
502 | } | |
503 | ||
504 | static void __exit nv_tco_cleanup_module(void) | |
505 | { | |
506 | platform_device_unregister(nv_tco_platform_device); | |
507 | platform_driver_unregister(&nv_tco_driver); | |
27c766aa | 508 | pr_info("NV TCO Watchdog Module Unloaded\n"); |
456c7301 MW |
509 | } |
510 | ||
511 | module_init(nv_tco_init_module); | |
512 | module_exit(nv_tco_cleanup_module); | |
513 | ||
514 | MODULE_AUTHOR("Mike Waychison"); | |
515 | MODULE_DESCRIPTION("TCO timer driver for NV chipsets"); | |
516 | MODULE_LICENSE("GPL"); |