809f41c30c4433dfb3e45b53835935608f95753e
[sfrench/cifs-2.6.git] / drivers / watchdog / nv_tco.c
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
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 */
47 static unsigned int tcobase;
48 static DEFINE_SPINLOCK(tco_lock);       /* Guards the hardware */
49 static unsigned long timer_alive;
50 static char tco_expect_close;
51 static struct pci_dev *tco_pci;
52
53 /* the watchdog platform device */
54 static struct platform_device *nv_tco_platform_device;
55
56 /* module parameters */
57 #define WATCHDOG_HEARTBEAT 30   /* 30 sec default heartbeat (2<heartbeat<39) */
58 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
59 module_param(heartbeat, int, 0);
60 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, "
61                             "default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
62
63 static int nowayout = WATCHDOG_NOWAYOUT;
64 module_param(nowayout, int, 0);
65 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
66                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
67
68 /*
69  * Some TCO specific functions
70  */
71 static 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
78 static 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
90 static 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
102 static 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
111 static 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
154 static 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
166 static 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
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  */
292 static DEFINE_PCI_DEVICE_TABLE(tco_pci_tbl) = {
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, },
297         { 0, },                 /* End of list */
298 };
299 MODULE_DEVICE_TABLE(pci, tco_pci_tbl);
300
301 /*
302  *      Init & exit routines
303  */
304
305 static unsigned char __devinit nv_tco_getdevice(void)
306 {
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;
376 out:
377         release_region(tcobase, 0x10);
378         return 0;
379 }
380
381 static 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
423 unreg_region:
424         release_region(tcobase, 0x10);
425         return ret;
426 }
427
428 static 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
451 static int __devexit nv_tco_remove(struct platform_device *dev)
452 {
453         if (tcobase)
454                 nv_tco_cleanup();
455
456         return 0;
457 }
458
459 static void nv_tco_shutdown(struct platform_device *dev)
460 {
461         u32 val;
462
463         tco_timer_stop();
464
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);
470 }
471
472 static 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
482 static 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
502 unreg_platform_driver:
503         platform_driver_unregister(&nv_tco_driver);
504         return err;
505 }
506
507 static 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
514 module_init(nv_tco_init_module);
515 module_exit(nv_tco_cleanup_module);
516
517 MODULE_AUTHOR("Mike Waychison");
518 MODULE_DESCRIPTION("TCO timer driver for NV chipsets");
519 MODULE_LICENSE("GPL");
520 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);