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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
Joe Perches27c766a2012-02-15 15:06:19 -080024#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25
Mike Waychison456c7302010-10-25 17:58:05 -070026#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
Mike Waychison456c7302010-10-25 17:58:05 -070046
47/* internal variables */
48static unsigned int tcobase;
49static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */
50static unsigned long timer_alive;
51static char tco_expect_close;
52static struct pci_dev *tco_pci;
53
54/* the watchdog platform device */
55static struct platform_device *nv_tco_platform_device;
56
57/* module parameters */
58#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat (2<heartbeat<39) */
59static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
60module_param(heartbeat, int, 0);
61MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, "
62 "default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
63
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010064static bool nowayout = WATCHDOG_NOWAYOUT;
65module_param(nowayout, bool, 0);
Mike Waychison456c7302010-10-25 17:58:05 -070066MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
67 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
68
69/*
70 * Some TCO specific functions
71 */
72static 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
79static 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
91static 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
103static 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
112static 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
155static 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
167static 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 {
Joe Perches27c766a2012-02-15 15:06:19 -0800173 pr_crit("Unexpected close, not stopping watchdog!\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700174 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
Bill Pemberton2d991a12012-11-19 13:21:41 -0500305static unsigned char 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 */
Joe Perches27c766a2012-02-15 15:06:19 -0800326 pr_err("failed to get tcobase address\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700327 return 0;
328 }
329 val &= 0xff00;
330 tcobase = val + 0x40;
331
332 if (!request_region(tcobase, 0x10, "NV TCO")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800333 pr_err("I/O address 0x%04x already in use\n", tcobase);
Mike Waychison456c7302010-10-25 17:58:05 -0700334 return 0;
335 }
336
337 /* Set a reasonable heartbeat before we stop the timer */
338 tco_timer_set_heartbeat(30);
339
340 /*
341 * Stop the TCO before we change anything so we don't race with
342 * a zeroed timer.
343 */
344 tco_timer_keepalive();
345 tco_timer_stop();
346
347 /* Disable SMI caused by TCO */
348 if (!request_region(MCP51_SMI_EN(tcobase), 4, "NV TCO")) {
Joe Perches27c766a2012-02-15 15:06:19 -0800349 pr_err("I/O address 0x%04x already in use\n",
Mike Waychison456c7302010-10-25 17:58:05 -0700350 MCP51_SMI_EN(tcobase));
351 goto out;
352 }
353 val = inl(MCP51_SMI_EN(tcobase));
354 val &= ~MCP51_SMI_EN_TCO;
355 outl(val, MCP51_SMI_EN(tcobase));
356 val = inl(MCP51_SMI_EN(tcobase));
357 release_region(MCP51_SMI_EN(tcobase), 4);
358 if (val & MCP51_SMI_EN_TCO) {
Joe Perches27c766a2012-02-15 15:06:19 -0800359 pr_err("Could not disable SMI caused by TCO\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700360 goto out;
361 }
362
363 /* Check chipset's NO_REBOOT bit */
364 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
365 val |= MCP51_SMBUS_SETUP_B_TCO_REBOOT;
366 pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
367 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
368 if (!(val & MCP51_SMBUS_SETUP_B_TCO_REBOOT)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800369 pr_err("failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700370 goto out;
371 }
372
373 return 1;
374out:
375 release_region(tcobase, 0x10);
376 return 0;
377}
378
Bill Pemberton2d991a12012-11-19 13:21:41 -0500379static int nv_tco_init(struct platform_device *dev)
Mike Waychison456c7302010-10-25 17:58:05 -0700380{
381 int ret;
382
383 /* Check whether or not the hardware watchdog is there */
384 if (!nv_tco_getdevice())
385 return -ENODEV;
386
387 /* Check to see if last reboot was due to watchdog timeout */
Joe Perches27c766a2012-02-15 15:06:19 -0800388 pr_info("Watchdog reboot %sdetected\n",
389 inl(TCO_STS(tcobase)) & TCO_STS_TCO2TO_STS ? "" : "not ");
Mike Waychison456c7302010-10-25 17:58:05 -0700390
391 /* Clear out the old status */
392 outl(TCO_STS_RESET, TCO_STS(tcobase));
393
394 /*
395 * Check that the heartbeat value is within it's range.
396 * If not, reset to the default.
397 */
398 if (tco_timer_set_heartbeat(heartbeat)) {
399 heartbeat = WATCHDOG_HEARTBEAT;
400 tco_timer_set_heartbeat(heartbeat);
Joe Perches27c766a2012-02-15 15:06:19 -0800401 pr_info("heartbeat value must be 2<heartbeat<39, using %d\n",
402 heartbeat);
Mike Waychison456c7302010-10-25 17:58:05 -0700403 }
404
405 ret = misc_register(&nv_tco_miscdev);
406 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800407 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
408 WATCHDOG_MINOR, ret);
Mike Waychison456c7302010-10-25 17:58:05 -0700409 goto unreg_region;
410 }
411
412 clear_bit(0, &timer_alive);
413
414 tco_timer_stop();
415
Joe Perches27c766a2012-02-15 15:06:19 -0800416 pr_info("initialized (0x%04x). heartbeat=%d sec (nowayout=%d)\n",
417 tcobase, heartbeat, nowayout);
Mike Waychison456c7302010-10-25 17:58:05 -0700418
419 return 0;
420
421unreg_region:
422 release_region(tcobase, 0x10);
423 return ret;
424}
425
Bill Pemberton4b12b892012-11-19 13:26:24 -0500426static void nv_tco_cleanup(void)
Mike Waychison456c7302010-10-25 17:58:05 -0700427{
428 u32 val;
429
430 /* Stop the timer before we leave */
431 if (!nowayout)
432 tco_timer_stop();
433
434 /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
435 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
436 val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT;
437 pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
438 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
439 if (val & MCP51_SMBUS_SETUP_B_TCO_REBOOT) {
Joe Perches27c766a2012-02-15 15:06:19 -0800440 pr_crit("Couldn't unset REBOOT bit. Machine may soon reset\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700441 }
442
443 /* Deregister */
444 misc_deregister(&nv_tco_miscdev);
445 release_region(tcobase, 0x10);
446}
447
Bill Pemberton4b12b892012-11-19 13:26:24 -0500448static int nv_tco_remove(struct platform_device *dev)
Mike Waychison456c7302010-10-25 17:58:05 -0700449{
450 if (tcobase)
451 nv_tco_cleanup();
452
453 return 0;
454}
455
456static void nv_tco_shutdown(struct platform_device *dev)
457{
Mart Gerrits6b01d302011-07-30 16:59:12 +0200458 u32 val;
459
Mike Waychison456c7302010-10-25 17:58:05 -0700460 tco_timer_stop();
Mart Gerrits6b01d302011-07-30 16:59:12 +0200461
462 /* Some BIOSes fail the POST (once) if the NO_REBOOT flag is not
463 * unset during shutdown. */
464 pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
465 val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT;
466 pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
Mike Waychison456c7302010-10-25 17:58:05 -0700467}
468
469static struct platform_driver nv_tco_driver = {
470 .probe = nv_tco_init,
Bill Pemberton82268712012-11-19 13:21:12 -0500471 .remove = nv_tco_remove,
Mike Waychison456c7302010-10-25 17:58:05 -0700472 .shutdown = nv_tco_shutdown,
473 .driver = {
474 .owner = THIS_MODULE,
475 .name = TCO_MODULE_NAME,
476 },
477};
478
479static int __init nv_tco_init_module(void)
480{
481 int err;
482
Joe Perches27c766a2012-02-15 15:06:19 -0800483 pr_info("NV TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
Mike Waychison456c7302010-10-25 17:58:05 -0700484
485 err = platform_driver_register(&nv_tco_driver);
486 if (err)
487 return err;
488
489 nv_tco_platform_device = platform_device_register_simple(
490 TCO_MODULE_NAME, -1, NULL, 0);
491 if (IS_ERR(nv_tco_platform_device)) {
492 err = PTR_ERR(nv_tco_platform_device);
493 goto unreg_platform_driver;
494 }
495
496 return 0;
497
498unreg_platform_driver:
499 platform_driver_unregister(&nv_tco_driver);
500 return err;
501}
502
503static void __exit nv_tco_cleanup_module(void)
504{
505 platform_device_unregister(nv_tco_platform_device);
506 platform_driver_unregister(&nv_tco_driver);
Joe Perches27c766a2012-02-15 15:06:19 -0800507 pr_info("NV TCO Watchdog Module Unloaded\n");
Mike Waychison456c7302010-10-25 17:58:05 -0700508}
509
510module_init(nv_tco_init_module);
511module_exit(nv_tco_cleanup_module);
512
513MODULE_AUTHOR("Mike Waychison");
514MODULE_DESCRIPTION("TCO timer driver for NV chipsets");
515MODULE_LICENSE("GPL");
516MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);