watchdog: nowayout is bool
[linux-2.6.git] / drivers / watchdog / sp5100_tco.c
1 /*
2  *      sp5100_tco :    TCO timer driver for sp5100 chipsets
3  *
4  *      (c) Copyright 2009 Google Inc., All Rights Reserved.
5  *
6  *      Based on 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  *      See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide"
17  */
18
19 /*
20  *      Includes, defines, variables, module parameters, ...
21  */
22
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/types.h>
28 #include <linux/miscdevice.h>
29 #include <linux/watchdog.h>
30 #include <linux/init.h>
31 #include <linux/fs.h>
32 #include <linux/pci.h>
33 #include <linux/ioport.h>
34 #include <linux/platform_device.h>
35 #include <linux/uaccess.h>
36 #include <linux/io.h>
37
38 #include "sp5100_tco.h"
39
40 /* Module and version information */
41 #define TCO_VERSION "0.01"
42 #define TCO_MODULE_NAME "SP5100 TCO timer"
43 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
44
45 /* internal variables */
46 static u32 tcobase_phys;
47 static void __iomem *tcobase;
48 static unsigned int pm_iobase;
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 *sp5100_tco_pci;
53
54 /* the watchdog platform device */
55 static struct platform_device *sp5100_tco_platform_device;
56
57 /* module parameters */
58
59 #define WATCHDOG_HEARTBEAT 60   /* 60 sec default heartbeat. */
60 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
61 module_param(heartbeat, int, 0);
62 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
63                  __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
64
65 static bool nowayout = WATCHDOG_NOWAYOUT;
66 module_param(nowayout, bool, 0);
67 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
68                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
69
70 /*
71  * Some TCO specific functions
72  */
73 static void tco_timer_start(void)
74 {
75         u32 val;
76         unsigned long flags;
77
78         spin_lock_irqsave(&tco_lock, flags);
79         val = readl(SP5100_WDT_CONTROL(tcobase));
80         val |= SP5100_WDT_START_STOP_BIT;
81         writel(val, SP5100_WDT_CONTROL(tcobase));
82         spin_unlock_irqrestore(&tco_lock, flags);
83 }
84
85 static void tco_timer_stop(void)
86 {
87         u32 val;
88         unsigned long flags;
89
90         spin_lock_irqsave(&tco_lock, flags);
91         val = readl(SP5100_WDT_CONTROL(tcobase));
92         val &= ~SP5100_WDT_START_STOP_BIT;
93         writel(val, SP5100_WDT_CONTROL(tcobase));
94         spin_unlock_irqrestore(&tco_lock, flags);
95 }
96
97 static void tco_timer_keepalive(void)
98 {
99         u32 val;
100         unsigned long flags;
101
102         spin_lock_irqsave(&tco_lock, flags);
103         val = readl(SP5100_WDT_CONTROL(tcobase));
104         val |= SP5100_WDT_TRIGGER_BIT;
105         writel(val, SP5100_WDT_CONTROL(tcobase));
106         spin_unlock_irqrestore(&tco_lock, flags);
107 }
108
109 static int tco_timer_set_heartbeat(int t)
110 {
111         unsigned long flags;
112
113         if (t < 0 || t > 0xffff)
114                 return -EINVAL;
115
116         /* Write new heartbeat to watchdog */
117         spin_lock_irqsave(&tco_lock, flags);
118         writel(t, SP5100_WDT_COUNT(tcobase));
119         spin_unlock_irqrestore(&tco_lock, flags);
120
121         heartbeat = t;
122         return 0;
123 }
124
125 /*
126  *      /dev/watchdog handling
127  */
128
129 static int sp5100_tco_open(struct inode *inode, struct file *file)
130 {
131         /* /dev/watchdog can only be opened once */
132         if (test_and_set_bit(0, &timer_alive))
133                 return -EBUSY;
134
135         /* Reload and activate timer */
136         tco_timer_start();
137         tco_timer_keepalive();
138         return nonseekable_open(inode, file);
139 }
140
141 static int sp5100_tco_release(struct inode *inode, struct file *file)
142 {
143         /* Shut off the timer. */
144         if (tco_expect_close == 42) {
145                 tco_timer_stop();
146         } else {
147                 pr_crit("Unexpected close, not stopping watchdog!\n");
148                 tco_timer_keepalive();
149         }
150         clear_bit(0, &timer_alive);
151         tco_expect_close = 0;
152         return 0;
153 }
154
155 static ssize_t sp5100_tco_write(struct file *file, const char __user *data,
156                                 size_t len, loff_t *ppos)
157 {
158         /* See if we got the magic character 'V' and reload the timer */
159         if (len) {
160                 if (!nowayout) {
161                         size_t i;
162
163                         /* note: just in case someone wrote the magic character
164                          * five months ago... */
165                         tco_expect_close = 0;
166
167                         /* scan to see whether or not we got the magic character
168                          */
169                         for (i = 0; i != len; i++) {
170                                 char c;
171                                 if (get_user(c, data + i))
172                                         return -EFAULT;
173                                 if (c == 'V')
174                                         tco_expect_close = 42;
175                         }
176                 }
177
178                 /* someone wrote to us, we should reload the timer */
179                 tco_timer_keepalive();
180         }
181         return len;
182 }
183
184 static long sp5100_tco_ioctl(struct file *file, unsigned int cmd,
185                              unsigned long arg)
186 {
187         int new_options, retval = -EINVAL;
188         int new_heartbeat;
189         void __user *argp = (void __user *)arg;
190         int __user *p = argp;
191         static const struct watchdog_info ident = {
192                 .options =              WDIOF_SETTIMEOUT |
193                                         WDIOF_KEEPALIVEPING |
194                                         WDIOF_MAGICCLOSE,
195                 .firmware_version =     0,
196                 .identity =             TCO_MODULE_NAME,
197         };
198
199         switch (cmd) {
200         case WDIOC_GETSUPPORT:
201                 return copy_to_user(argp, &ident,
202                         sizeof(ident)) ? -EFAULT : 0;
203         case WDIOC_GETSTATUS:
204         case WDIOC_GETBOOTSTATUS:
205                 return put_user(0, p);
206         case WDIOC_SETOPTIONS:
207                 if (get_user(new_options, p))
208                         return -EFAULT;
209                 if (new_options & WDIOS_DISABLECARD) {
210                         tco_timer_stop();
211                         retval = 0;
212                 }
213                 if (new_options & WDIOS_ENABLECARD) {
214                         tco_timer_start();
215                         tco_timer_keepalive();
216                         retval = 0;
217                 }
218                 return retval;
219         case WDIOC_KEEPALIVE:
220                 tco_timer_keepalive();
221                 return 0;
222         case WDIOC_SETTIMEOUT:
223                 if (get_user(new_heartbeat, p))
224                         return -EFAULT;
225                 if (tco_timer_set_heartbeat(new_heartbeat))
226                         return -EINVAL;
227                 tco_timer_keepalive();
228                 /* Fall through */
229         case WDIOC_GETTIMEOUT:
230                 return put_user(heartbeat, p);
231         default:
232                 return -ENOTTY;
233         }
234 }
235
236 /*
237  * Kernel Interfaces
238  */
239
240 static const struct file_operations sp5100_tco_fops = {
241         .owner =                THIS_MODULE,
242         .llseek =               no_llseek,
243         .write =                sp5100_tco_write,
244         .unlocked_ioctl =       sp5100_tco_ioctl,
245         .open =                 sp5100_tco_open,
246         .release =              sp5100_tco_release,
247 };
248
249 static struct miscdevice sp5100_tco_miscdev = {
250         .minor =        WATCHDOG_MINOR,
251         .name =         "watchdog",
252         .fops =         &sp5100_tco_fops,
253 };
254
255 /*
256  * Data for PCI driver interface
257  *
258  * This data only exists for exporting the supported
259  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
260  * register a pci_driver, because someone else might
261  * want to register another driver on the same PCI id.
262  */
263 static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl) = {
264         { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
265           PCI_ANY_ID, },
266         { 0, },                 /* End of list */
267 };
268 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
269
270 /*
271  * Init & exit routines
272  */
273
274 static unsigned char __devinit sp5100_tco_setupdevice(void)
275 {
276         struct pci_dev *dev = NULL;
277         u32 val;
278
279         /* Match the PCI device */
280         for_each_pci_dev(dev) {
281                 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
282                         sp5100_tco_pci = dev;
283                         break;
284                 }
285         }
286
287         if (!sp5100_tco_pci)
288                 return 0;
289
290         /* Request the IO ports used by this driver */
291         pm_iobase = SP5100_IO_PM_INDEX_REG;
292         if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) {
293                 pr_err("I/O address 0x%04x already in use\n", pm_iobase);
294                 goto exit;
295         }
296
297         /* Find the watchdog base address. */
298         outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG);
299         val = inb(SP5100_IO_PM_DATA_REG);
300         outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG);
301         val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
302         outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG);
303         val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
304         outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG);
305         /* Low three bits of BASE0 are reserved. */
306         val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8);
307
308         if (!request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
309                                                                 "SP5100 TCO")) {
310                 pr_err("mmio address 0x%04x already in use\n", val);
311                 goto unreg_region;
312         }
313         tcobase_phys = val;
314
315         tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
316         if (tcobase == 0) {
317                 pr_err("failed to get tcobase address\n");
318                 goto unreg_mem_region;
319         }
320
321         /* Enable watchdog decode bit */
322         pci_read_config_dword(sp5100_tco_pci,
323                               SP5100_PCI_WATCHDOG_MISC_REG,
324                               &val);
325
326         val |= SP5100_PCI_WATCHDOG_DECODE_EN;
327
328         pci_write_config_dword(sp5100_tco_pci,
329                                SP5100_PCI_WATCHDOG_MISC_REG,
330                                val);
331
332         /* Enable Watchdog timer and set the resolution to 1 sec. */
333         outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
334         val = inb(SP5100_IO_PM_DATA_REG);
335         val |= SP5100_PM_WATCHDOG_SECOND_RES;
336         val &= ~SP5100_PM_WATCHDOG_DISABLE;
337         outb(val, SP5100_IO_PM_DATA_REG);
338
339         /* Check that the watchdog action is set to reset the system. */
340         val = readl(SP5100_WDT_CONTROL(tcobase));
341         val &= ~SP5100_PM_WATCHDOG_ACTION_RESET;
342         writel(val, SP5100_WDT_CONTROL(tcobase));
343
344         /* Set a reasonable heartbeat before we stop the timer */
345         tco_timer_set_heartbeat(heartbeat);
346
347         /*
348          * Stop the TCO before we change anything so we don't race with
349          * a zeroed timer.
350          */
351         tco_timer_stop();
352
353         /* Done */
354         return 1;
355
356 unreg_mem_region:
357         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
358 unreg_region:
359         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
360 exit:
361         return 0;
362 }
363
364 static int __devinit sp5100_tco_init(struct platform_device *dev)
365 {
366         int ret;
367         u32 val;
368
369         /* Check whether or not the hardware watchdog is there. If found, then
370          * set it up.
371          */
372         if (!sp5100_tco_setupdevice())
373                 return -ENODEV;
374
375         /* Check to see if last reboot was due to watchdog timeout */
376         pr_info("Watchdog reboot %sdetected\n",
377                 readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ?
378                 "" : "not ");
379
380         /* Clear out the old status */
381         val = readl(SP5100_WDT_CONTROL(tcobase));
382         val &= ~SP5100_PM_WATCHDOG_FIRED;
383         writel(val, SP5100_WDT_CONTROL(tcobase));
384
385         /*
386          * Check that the heartbeat value is within it's range.
387          * If not, reset to the default.
388          */
389         if (tco_timer_set_heartbeat(heartbeat)) {
390                 heartbeat = WATCHDOG_HEARTBEAT;
391                 tco_timer_set_heartbeat(heartbeat);
392         }
393
394         ret = misc_register(&sp5100_tco_miscdev);
395         if (ret != 0) {
396                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
397                        WATCHDOG_MINOR, ret);
398                 goto exit;
399         }
400
401         clear_bit(0, &timer_alive);
402
403         pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
404                 tcobase, heartbeat, nowayout);
405
406         return 0;
407
408 exit:
409         iounmap(tcobase);
410         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
411         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
412         return ret;
413 }
414
415 static void __devexit sp5100_tco_cleanup(void)
416 {
417         /* Stop the timer before we leave */
418         if (!nowayout)
419                 tco_timer_stop();
420
421         /* Deregister */
422         misc_deregister(&sp5100_tco_miscdev);
423         iounmap(tcobase);
424         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
425         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
426 }
427
428 static int __devexit sp5100_tco_remove(struct platform_device *dev)
429 {
430         if (tcobase)
431                 sp5100_tco_cleanup();
432         return 0;
433 }
434
435 static void sp5100_tco_shutdown(struct platform_device *dev)
436 {
437         tco_timer_stop();
438 }
439
440 static struct platform_driver sp5100_tco_driver = {
441         .probe          = sp5100_tco_init,
442         .remove         = __devexit_p(sp5100_tco_remove),
443         .shutdown       = sp5100_tco_shutdown,
444         .driver         = {
445                 .owner  = THIS_MODULE,
446                 .name   = TCO_MODULE_NAME,
447         },
448 };
449
450 static int __init sp5100_tco_init_module(void)
451 {
452         int err;
453
454         pr_info("SP5100 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
455
456         err = platform_driver_register(&sp5100_tco_driver);
457         if (err)
458                 return err;
459
460         sp5100_tco_platform_device = platform_device_register_simple(
461                                         TCO_MODULE_NAME, -1, NULL, 0);
462         if (IS_ERR(sp5100_tco_platform_device)) {
463                 err = PTR_ERR(sp5100_tco_platform_device);
464                 goto unreg_platform_driver;
465         }
466
467         return 0;
468
469 unreg_platform_driver:
470         platform_driver_unregister(&sp5100_tco_driver);
471         return err;
472 }
473
474 static void __exit sp5100_tco_cleanup_module(void)
475 {
476         platform_device_unregister(sp5100_tco_platform_device);
477         platform_driver_unregister(&sp5100_tco_driver);
478         pr_info("SP5100 TCO Watchdog Module Unloaded\n");
479 }
480
481 module_init(sp5100_tco_init_module);
482 module_exit(sp5100_tco_cleanup_module);
483
484 MODULE_AUTHOR("Priyanka Gupta");
485 MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset");
486 MODULE_LICENSE("GPL");
487 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);