diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/alim7101_wdt.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/alim7101_wdt.c')
-rw-r--r-- | drivers/char/watchdog/alim7101_wdt.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/char/watchdog/alim7101_wdt.c b/drivers/char/watchdog/alim7101_wdt.c new file mode 100644 index 000000000000..90c091d9e0f5 --- /dev/null +++ b/drivers/char/watchdog/alim7101_wdt.c | |||
@@ -0,0 +1,421 @@ | |||
1 | /* | ||
2 | * ALi M7101 PMU Computer Watchdog Timer driver | ||
3 | * | ||
4 | * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net> | ||
5 | * and the Cobalt kernel WDT timer driver by Tim Hockin | ||
6 | * <thockin@cobaltnet.com> | ||
7 | * | ||
8 | * (c)2002 Steve Hill <steve@navaho.co.uk> | ||
9 | * | ||
10 | * This WDT driver is different from most other Linux WDT | ||
11 | * drivers in that the driver will ping the watchdog by itself, | ||
12 | * because this particular WDT has a very short timeout (1.6 | ||
13 | * seconds) and it would be insane to count on any userspace | ||
14 | * daemon always getting scheduled within that time frame. | ||
15 | * | ||
16 | * Additions: | ||
17 | * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs | ||
18 | * found on very old cobalt hardware. | ||
19 | * -- Mike Waychison <michael.waychison@sun.com> | ||
20 | */ | ||
21 | |||
22 | #include <linux/module.h> | ||
23 | #include <linux/moduleparam.h> | ||
24 | #include <linux/types.h> | ||
25 | #include <linux/timer.h> | ||
26 | #include <linux/miscdevice.h> | ||
27 | #include <linux/watchdog.h> | ||
28 | #include <linux/ioport.h> | ||
29 | #include <linux/notifier.h> | ||
30 | #include <linux/reboot.h> | ||
31 | #include <linux/init.h> | ||
32 | #include <linux/fs.h> | ||
33 | #include <linux/pci.h> | ||
34 | |||
35 | #include <asm/io.h> | ||
36 | #include <asm/uaccess.h> | ||
37 | #include <asm/system.h> | ||
38 | |||
39 | #define OUR_NAME "alim7101_wdt" | ||
40 | #define PFX OUR_NAME ": " | ||
41 | |||
42 | #define WDT_ENABLE 0x9C | ||
43 | #define WDT_DISABLE 0x8C | ||
44 | |||
45 | #define ALI_7101_WDT 0x92 | ||
46 | #define ALI_7101_GPIO 0x7D | ||
47 | #define ALI_7101_GPIO_O 0x7E | ||
48 | #define ALI_WDT_ARM 0x01 | ||
49 | |||
50 | /* | ||
51 | * We're going to use a 1 second timeout. | ||
52 | * If we reset the watchdog every ~250ms we should be safe. */ | ||
53 | |||
54 | #define WDT_INTERVAL (HZ/4+1) | ||
55 | |||
56 | /* | ||
57 | * We must not require too good response from the userspace daemon. | ||
58 | * Here we require the userspace daemon to send us a heartbeat | ||
59 | * char to /dev/watchdog every 30 seconds. | ||
60 | */ | ||
61 | |||
62 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | ||
63 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ | ||
64 | module_param(timeout, int, 0); | ||
65 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | ||
66 | |||
67 | static int use_gpio = 0; /* Use the pic (for a1d revision alim7101) */ | ||
68 | module_param(use_gpio, int, 0); | ||
69 | MODULE_PARM_DESC(use_gpio, "Use the gpio watchdog. (required by old cobalt boards)"); | ||
70 | |||
71 | static void wdt_timer_ping(unsigned long); | ||
72 | static struct timer_list timer; | ||
73 | static unsigned long next_heartbeat; | ||
74 | static unsigned long wdt_is_open; | ||
75 | static char wdt_expect_close; | ||
76 | static struct pci_dev *alim7101_pmu; | ||
77 | |||
78 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
79 | static int nowayout = 1; | ||
80 | #else | ||
81 | static int nowayout = 0; | ||
82 | #endif | ||
83 | |||
84 | module_param(nowayout, int, 0); | ||
85 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | ||
86 | |||
87 | /* | ||
88 | * Whack the dog | ||
89 | */ | ||
90 | |||
91 | static void wdt_timer_ping(unsigned long data) | ||
92 | { | ||
93 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | ||
94 | * we agree to ping the WDT | ||
95 | */ | ||
96 | char tmp; | ||
97 | |||
98 | if(time_before(jiffies, next_heartbeat)) | ||
99 | { | ||
100 | /* Ping the WDT (this is actually a disarm/arm sequence) */ | ||
101 | pci_read_config_byte(alim7101_pmu, 0x92, &tmp); | ||
102 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | ||
103 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | ||
104 | if (use_gpio) { | ||
105 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | ||
106 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | ||
107 | | 0x20); | ||
108 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | ||
109 | & ~0x20); | ||
110 | } | ||
111 | } else { | ||
112 | printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); | ||
113 | } | ||
114 | /* Re-set the timer interval */ | ||
115 | timer.expires = jiffies + WDT_INTERVAL; | ||
116 | add_timer(&timer); | ||
117 | } | ||
118 | |||
119 | /* | ||
120 | * Utility routines | ||
121 | */ | ||
122 | |||
123 | static void wdt_change(int writeval) | ||
124 | { | ||
125 | char tmp; | ||
126 | |||
127 | pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); | ||
128 | if (writeval == WDT_ENABLE) { | ||
129 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | ||
130 | if (use_gpio) { | ||
131 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | ||
132 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp & ~0x20); | ||
133 | } | ||
134 | |||
135 | } else { | ||
136 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | ||
137 | if (use_gpio) { | ||
138 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | ||
139 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | 0x20); | ||
140 | } | ||
141 | } | ||
142 | } | ||
143 | |||
144 | static void wdt_startup(void) | ||
145 | { | ||
146 | next_heartbeat = jiffies + (timeout * HZ); | ||
147 | |||
148 | /* We must enable before we kick off the timer in case the timer | ||
149 | occurs as we ping it */ | ||
150 | |||
151 | wdt_change(WDT_ENABLE); | ||
152 | |||
153 | /* Start the timer */ | ||
154 | timer.expires = jiffies + WDT_INTERVAL; | ||
155 | add_timer(&timer); | ||
156 | |||
157 | |||
158 | printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); | ||
159 | } | ||
160 | |||
161 | static void wdt_turnoff(void) | ||
162 | { | ||
163 | /* Stop the timer */ | ||
164 | del_timer_sync(&timer); | ||
165 | wdt_change(WDT_DISABLE); | ||
166 | printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); | ||
167 | } | ||
168 | |||
169 | static void wdt_keepalive(void) | ||
170 | { | ||
171 | /* user land ping */ | ||
172 | next_heartbeat = jiffies + (timeout * HZ); | ||
173 | } | ||
174 | |||
175 | /* | ||
176 | * /dev/watchdog handling | ||
177 | */ | ||
178 | |||
179 | static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) | ||
180 | { | ||
181 | /* See if we got the magic character 'V' and reload the timer */ | ||
182 | if(count) { | ||
183 | if (!nowayout) { | ||
184 | size_t ofs; | ||
185 | |||
186 | /* note: just in case someone wrote the magic character | ||
187 | * five months ago... */ | ||
188 | wdt_expect_close = 0; | ||
189 | |||
190 | /* now scan */ | ||
191 | for (ofs = 0; ofs != count; ofs++) { | ||
192 | char c; | ||
193 | if (get_user(c, buf+ofs)) | ||
194 | return -EFAULT; | ||
195 | if (c == 'V') | ||
196 | wdt_expect_close = 42; | ||
197 | } | ||
198 | } | ||
199 | /* someone wrote to us, we should restart timer */ | ||
200 | wdt_keepalive(); | ||
201 | } | ||
202 | return count; | ||
203 | } | ||
204 | |||
205 | static int fop_open(struct inode * inode, struct file * file) | ||
206 | { | ||
207 | /* Just in case we're already talking to someone... */ | ||
208 | if(test_and_set_bit(0, &wdt_is_open)) | ||
209 | return -EBUSY; | ||
210 | /* Good, fire up the show */ | ||
211 | wdt_startup(); | ||
212 | return nonseekable_open(inode, file); | ||
213 | } | ||
214 | |||
215 | static int fop_close(struct inode * inode, struct file * file) | ||
216 | { | ||
217 | if(wdt_expect_close == 42) | ||
218 | wdt_turnoff(); | ||
219 | else { | ||
220 | /* wim: shouldn't there be a: del_timer(&timer); */ | ||
221 | printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); | ||
222 | } | ||
223 | clear_bit(0, &wdt_is_open); | ||
224 | wdt_expect_close = 0; | ||
225 | return 0; | ||
226 | } | ||
227 | |||
228 | static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | ||
229 | { | ||
230 | void __user *argp = (void __user *)arg; | ||
231 | int __user *p = argp; | ||
232 | static struct watchdog_info ident = | ||
233 | { | ||
234 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | ||
235 | .firmware_version = 1, | ||
236 | .identity = "ALiM7101", | ||
237 | }; | ||
238 | |||
239 | switch(cmd) | ||
240 | { | ||
241 | case WDIOC_GETSUPPORT: | ||
242 | return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; | ||
243 | case WDIOC_GETSTATUS: | ||
244 | case WDIOC_GETBOOTSTATUS: | ||
245 | return put_user(0, p); | ||
246 | case WDIOC_KEEPALIVE: | ||
247 | wdt_keepalive(); | ||
248 | return 0; | ||
249 | case WDIOC_SETOPTIONS: | ||
250 | { | ||
251 | int new_options, retval = -EINVAL; | ||
252 | |||
253 | if(get_user(new_options, p)) | ||
254 | return -EFAULT; | ||
255 | |||
256 | if(new_options & WDIOS_DISABLECARD) { | ||
257 | wdt_turnoff(); | ||
258 | retval = 0; | ||
259 | } | ||
260 | |||
261 | if(new_options & WDIOS_ENABLECARD) { | ||
262 | wdt_startup(); | ||
263 | retval = 0; | ||
264 | } | ||
265 | |||
266 | return retval; | ||
267 | } | ||
268 | case WDIOC_SETTIMEOUT: | ||
269 | { | ||
270 | int new_timeout; | ||
271 | |||
272 | if(get_user(new_timeout, p)) | ||
273 | return -EFAULT; | ||
274 | |||
275 | if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ | ||
276 | return -EINVAL; | ||
277 | |||
278 | timeout = new_timeout; | ||
279 | wdt_keepalive(); | ||
280 | /* Fall through */ | ||
281 | } | ||
282 | case WDIOC_GETTIMEOUT: | ||
283 | return put_user(timeout, p); | ||
284 | default: | ||
285 | return -ENOIOCTLCMD; | ||
286 | } | ||
287 | } | ||
288 | |||
289 | static struct file_operations wdt_fops = { | ||
290 | .owner= THIS_MODULE, | ||
291 | .llseek= no_llseek, | ||
292 | .write= fop_write, | ||
293 | .open= fop_open, | ||
294 | .release= fop_close, | ||
295 | .ioctl= fop_ioctl, | ||
296 | }; | ||
297 | |||
298 | static struct miscdevice wdt_miscdev = { | ||
299 | .minor=WATCHDOG_MINOR, | ||
300 | .name="watchdog", | ||
301 | .fops=&wdt_fops, | ||
302 | }; | ||
303 | |||
304 | /* | ||
305 | * Notifier for system down | ||
306 | */ | ||
307 | |||
308 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | ||
309 | { | ||
310 | if (code==SYS_DOWN || code==SYS_HALT) | ||
311 | wdt_turnoff(); | ||
312 | |||
313 | if (code==SYS_RESTART) { | ||
314 | /* | ||
315 | * Cobalt devices have no way of rebooting themselves other than | ||
316 | * getting the watchdog to pull reset, so we restart the watchdog on | ||
317 | * reboot with no heartbeat | ||
318 | */ | ||
319 | wdt_change(WDT_ENABLE); | ||
320 | printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n"); | ||
321 | } | ||
322 | return NOTIFY_DONE; | ||
323 | } | ||
324 | |||
325 | /* | ||
326 | * The WDT needs to learn about soft shutdowns in order to | ||
327 | * turn the timebomb registers off. | ||
328 | */ | ||
329 | |||
330 | static struct notifier_block wdt_notifier= | ||
331 | { | ||
332 | .notifier_call = wdt_notify_sys, | ||
333 | }; | ||
334 | |||
335 | static void __exit alim7101_wdt_unload(void) | ||
336 | { | ||
337 | wdt_turnoff(); | ||
338 | /* Deregister */ | ||
339 | misc_deregister(&wdt_miscdev); | ||
340 | unregister_reboot_notifier(&wdt_notifier); | ||
341 | } | ||
342 | |||
343 | static int __init alim7101_wdt_init(void) | ||
344 | { | ||
345 | int rc = -EBUSY; | ||
346 | struct pci_dev *ali1543_south; | ||
347 | char tmp; | ||
348 | |||
349 | printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n"); | ||
350 | alim7101_pmu = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,NULL); | ||
351 | if (!alim7101_pmu) { | ||
352 | printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n"); | ||
353 | return -EBUSY; | ||
354 | } | ||
355 | |||
356 | /* Set the WDT in the PMU to 1 second */ | ||
357 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); | ||
358 | |||
359 | ali1543_south = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL); | ||
360 | if (!ali1543_south) { | ||
361 | printk(KERN_INFO PFX "ALi 1543 South-Bridge not present - WDT not set\n"); | ||
362 | return -EBUSY; | ||
363 | } | ||
364 | pci_read_config_byte(ali1543_south, 0x5e, &tmp); | ||
365 | if ((tmp & 0x1e) == 0x00) { | ||
366 | if (!use_gpio) { | ||
367 | printk(KERN_INFO PFX "Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); | ||
368 | return -EBUSY; | ||
369 | } | ||
370 | nowayout = 1; | ||
371 | } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { | ||
372 | printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); | ||
373 | return -EBUSY; | ||
374 | } | ||
375 | |||
376 | if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ | ||
377 | { | ||
378 | timeout = WATCHDOG_TIMEOUT; | ||
379 | printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", | ||
380 | timeout); | ||
381 | } | ||
382 | |||
383 | init_timer(&timer); | ||
384 | timer.function = wdt_timer_ping; | ||
385 | timer.data = 1; | ||
386 | |||
387 | rc = misc_register(&wdt_miscdev); | ||
388 | if (rc) { | ||
389 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
390 | wdt_miscdev.minor, rc); | ||
391 | goto err_out; | ||
392 | } | ||
393 | |||
394 | rc = register_reboot_notifier(&wdt_notifier); | ||
395 | if (rc) { | ||
396 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
397 | rc); | ||
398 | goto err_out_miscdev; | ||
399 | } | ||
400 | |||
401 | if (nowayout) { | ||
402 | __module_get(THIS_MODULE); | ||
403 | } | ||
404 | |||
405 | printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", | ||
406 | timeout, nowayout); | ||
407 | return 0; | ||
408 | |||
409 | err_out_miscdev: | ||
410 | misc_deregister(&wdt_miscdev); | ||
411 | err_out: | ||
412 | return rc; | ||
413 | } | ||
414 | |||
415 | module_init(alim7101_wdt_init); | ||
416 | module_exit(alim7101_wdt_unload); | ||
417 | |||
418 | MODULE_AUTHOR("Steve Hill"); | ||
419 | MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); | ||
420 | MODULE_LICENSE("GPL"); | ||
421 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||