blob: 809f41c30c4433dfb3e45b53835935608f95753e [file] [log] [blame]
Mike Waychison456c7302010-10-25 17:58:05 -07001/*
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
24#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/types.h>
27#include <linux/miscdevice.h>
28#include <linux/watchdog.h>
29#include <linux/init.h>
30#include <linux/fs.h>
31#include <linux/pci.h>
32#include <linux/ioport.h>
33#include <linux/jiffies.h>
34#include <linux/platform_device.h>
35#include <linux/uaccess.h>
36#include <linux/io.h>
37
38#include "nv_tco.h"
39
40/* Module and version information */
41#define TCO_VERSION "0.01"
42#define TCO_MODULE_NAME "NV_TCO"
43#define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION
44#define PFX TCO_MODULE_NAME ": "
45
46/* internal variables */
47static unsigned int tcobase;
48static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */
49static unsigned long timer_alive;
50static char tco_expect_close;
51static struct pci_dev *tco_pci;
52
53/* the watchdog platform device */
54static struct platform_device *nv_tco_platform_device;
55
56/* module parameters */
57#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat (2<heartbeat<39) */
58static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
59module_param(heartbeat, int, 0);
60MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, "
61 "default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
62
63static int nowayout = WATCHDOG_NOWAYOUT;
64module_param(nowayout, int, 0);
65MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
66 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
67
68/*
69 * Some TCO specific functions
70 */
71static inline unsigned char seconds_to_ticks(int seconds)
72{
73 /* the internal timer is stored as ticks which decrement
74 * every 0.6 seconds */
75 return (seconds * 10) / 6;
76}
77
78static void tco_timer_start(void)
79{
80 u32 val;
81 unsigned long flags;
82
83 spin_lock_irqsave(&tco_lock, flags);
84 val = inl(TCO_CNT(tcobase));
85 val &= ~TCO_CNT_TCOHALT;
86 outl(val, TCO_CNT(tcobase));
87 spin_unlock_irqrestore(&tco_lock, flags);
88}
89
90static void tco_timer_stop(void)
91{
92 u32 val;
93 unsigned long flags;
94
95 spin_lock_irqsave(&tco_lock, flags);
96 val = inl(TCO_CNT(tcobase));
97 val |= TCO_CNT_TCOHALT;
98 outl(val, TCO_CNT(tcobase));
99 spin_unlock_irqrestore(&tco_lock, flags);
100}
101
102static void tco_timer_keepalive(void)
103{
104 unsigned long flags;
105
106 spin_lock_irqsave(&tco_lock, flags);
107 outb(0x01, TCO_RLD(tcobase));
108 spin_unlock_irqrestore(&tco_lock, flags);
109}
110
111static int tco_timer_set_heartbeat(int t)
112{
113 int ret = 0;
114 unsigned char tmrval;
115 unsigned long flags;
116 u8 val;
117
118 /*
119 * note seconds_to_ticks(t) > t, so if t > 0x3f, so is
120 * tmrval=seconds_to_ticks(t). Check that the count in seconds isn't
121 * out of range on it's own (to avoid overflow in tmrval).
122 */
123 if (t < 0 || t > 0x3f)
124 return -EINVAL;
125 tmrval = seconds_to_ticks(t);
126
127 /* "Values of 0h-3h are ignored and should not be attempted" */
128 if (tmrval > 0x3f || tmrval < 0x04)
129 return -EINVAL;
130
131 /* Write new heartbeat to watchdog */
132 spin_lock_irqsave(&tco_lock, flags);
133 val = inb(TCO_TMR(tcobase));
134 val &= 0xc0;
135 val |= tmrval;
136 outb(val, TCO_TMR(tcobase));
137 val = inb(TCO_TMR(tcobase));
138
139 if ((val & 0x3f) != tmrval)
140 ret = -EINVAL;
141 spin_unlock_irqrestore(&tco_lock, flags);
142
143 if (ret)
144 return ret;
145
146 heartbeat = t;
147 return 0;
148}
149
150/*
151 * /dev/watchdog handling
152 */
153
154static int nv_tco_open(struct inode *inode, struct file *file)
155{
156 /* /dev/watchdog can only be opened once */
157 if (test_and_set_bit(0, &timer_alive))
158 return -EBUSY;
159
160 /* Reload and activate timer */
161 tco_timer_keepalive();
162 tco_timer_start();
163 return nonseekable_open(inode, file);
164}
165
166static int nv_tco_release(struct inode *inode, struct file *file)
167{
168 /* Shut off the timer */
169 if (tco_expect_close == 42) {
170 tco_timer_stop();
171 } else {
172 printk(KERN_CRIT PFX "Unexpected close, not stopping "
173 "watchdog!\n");
174 tco_timer_keepalive();
175 }
176 clear_bit(0, &timer_alive);
177 tco_expect_close = 0;
178 return 0;
179}
180
181static 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
214static 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
269static 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
278static 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 */
Wim Van Sebroeck4562f532011-02-21 12:16:44 +0000292static DEFINE_PCI_DEVICE_TABLE(tco_pci_tbl) = {
Mike Waychison456c7302010-10-25 17:58:05 -0700293 { 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, },
297 { 0, }, /* End of list */
298};
299MODULE_DEVICE_TABLE(pci, tco_pci_tbl);
300
301/*
302 * Init & exit routines
303 */
304
Randy Dunlap708d4242011-03-24 13:32:44 -0700305static unsigned char __devinit nv_tco_getdevice(void)
Mike Waychison456c7302010-10-25 17:58:05 -0700306{
307 struct pci_dev *dev = NULL;
308 u32 val;
309
310 /* Find the PCI device */
311 for_each_pci_dev(dev) {
312 if (pci_match_id(tco_pci_tbl, dev) != NULL) {
313 tco_pci = dev;
314 break;
315 }
316 }
317
318 if (!tco_pci)
319 return 0;
320
321 /* Find the base io port */
322 pci_read_config_dword(tco_pci, 0x64, &val);
323 val &= 0xffff;
324 if (val == 0x0001 || val == 0x0000) {
325 /* Something is wrong here, bar isn't setup */
326 printk(KERN_ERR PFX "failed to get tcobase address\n");
327 return 0;
328 }
329 val &= 0xff00;
330 tcobase = val + 0x40;
331
332 if (!request_region(tcobase, 0x10, "NV TCO")) {
333 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
334 tcobase);
335 return 0;
336 }
337
338 /* Set a reasonable heartbeat before we stop the timer */
339 tco_timer_set_heartbeat(30);
340
341 /*
342 * Stop the TCO before we change anything so we don't race with
343 * a zeroed timer.
344 */
345 tco_timer_keepalive();
346 tco_timer_stop();
347
348 /* Disable SMI caused by TCO */
349 if (!request_region(MCP51_SMI_EN(tcobase), 4, "NV TCO")) {
350 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
351 MCP51_SMI_EN(tcobase));
352 goto out;
353 }
354 val = inl(MCP51_SMI_EN(tcobase));
355 val &= ~MCP51_SMI_EN_TCO;
356 outl(val, MCP51_SMI_EN(tcobase));
357 val = inl(MCP51_SMI_EN(tcobase));
358 release_region(MCP51_SMI_EN(tcobase), 4);
359 if (val & MCP51_SMI_EN_TCO) {
360 printk(KERN_ERR PFX "Could not disable SMI caused by TCO\n");
361 goto out;
362 }
363
364 /* Check chipset's NO_REBOOT bit */
365 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
366 val |= MCP51_SMBUS_SETUP_B_TCO_REBOOT;
367 pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
368 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
369 if (!(val & MCP51_SMBUS_SETUP_B_TCO_REBOOT)) {
370 printk(KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot "
371 "disabled by hardware\n");
372 goto out;
373 }
374
375 return 1;
376out:
377 release_region(tcobase, 0x10);
378 return 0;
379}
380
381static int __devinit nv_tco_init(struct platform_device *dev)
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 */
390 printk(KERN_INFO PFX "Watchdog reboot %sdetected.\n",
391 inl(TCO_STS(tcobase)) & TCO_STS_TCO2TO_STS ? "" : "not ");
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);
403 printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39, "
404 "using %d\n", heartbeat);
405 }
406
407 ret = misc_register(&nv_tco_miscdev);
408 if (ret != 0) {
409 printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
410 "(err=%d)\n", WATCHDOG_MINOR, ret);
411 goto unreg_region;
412 }
413
414 clear_bit(0, &timer_alive);
415
416 tco_timer_stop();
417
418 printk(KERN_INFO PFX "initialized (0x%04x). heartbeat=%d sec "
419 "(nowayout=%d)\n", tcobase, heartbeat, nowayout);
420
421 return 0;
422
423unreg_region:
424 release_region(tcobase, 0x10);
425 return ret;
426}
427
428static void __devexit nv_tco_cleanup(void)
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) {
442 printk(KERN_CRIT PFX "Couldn't unset REBOOT bit. Machine may "
443 "soon reset\n");
444 }
445
446 /* Deregister */
447 misc_deregister(&nv_tco_miscdev);
448 release_region(tcobase, 0x10);
449}
450
451static int __devexit nv_tco_remove(struct platform_device *dev)
452{
453 if (tcobase)
454 nv_tco_cleanup();
455
456 return 0;
457}
458
459static void nv_tco_shutdown(struct platform_device *dev)
460{
Mart Gerrits6b01d302011-07-30 16:59:12 +0200461 u32 val;
462
Mike Waychison456c7302010-10-25 17:58:05 -0700463 tco_timer_stop();
Mart Gerrits6b01d302011-07-30 16:59:12 +0200464
465 /* Some BIOSes fail the POST (once) if the NO_REBOOT flag is not
466 * unset during shutdown. */
467 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
468 val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT;
469 pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
Mike Waychison456c7302010-10-25 17:58:05 -0700470}
471
472static struct platform_driver nv_tco_driver = {
473 .probe = nv_tco_init,
474 .remove = __devexit_p(nv_tco_remove),
475 .shutdown = nv_tco_shutdown,
476 .driver = {
477 .owner = THIS_MODULE,
478 .name = TCO_MODULE_NAME,
479 },
480};
481
482static int __init nv_tco_init_module(void)
483{
484 int err;
485
486 printk(KERN_INFO PFX "NV TCO WatchDog Timer Driver v%s\n",
487 TCO_VERSION);
488
489 err = platform_driver_register(&nv_tco_driver);
490 if (err)
491 return err;
492
493 nv_tco_platform_device = platform_device_register_simple(
494 TCO_MODULE_NAME, -1, NULL, 0);
495 if (IS_ERR(nv_tco_platform_device)) {
496 err = PTR_ERR(nv_tco_platform_device);
497 goto unreg_platform_driver;
498 }
499
500 return 0;
501
502unreg_platform_driver:
503 platform_driver_unregister(&nv_tco_driver);
504 return err;
505}
506
507static void __exit nv_tco_cleanup_module(void)
508{
509 platform_device_unregister(nv_tco_platform_device);
510 platform_driver_unregister(&nv_tco_driver);
511 printk(KERN_INFO PFX "NV TCO Watchdog Module Unloaded.\n");
512}
513
514module_init(nv_tco_init_module);
515module_exit(nv_tco_cleanup_module);
516
517MODULE_AUTHOR("Mike Waychison");
518MODULE_DESCRIPTION("TCO timer driver for NV chipsets");
519MODULE_LICENSE("GPL");
520MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);