diff options
Diffstat (limited to 'Documentation/watchdog')
-rw-r--r-- | Documentation/watchdog/pcwd-watchdog.txt | 8 | ||||
-rw-r--r-- | Documentation/watchdog/watchdog-api.txt | 236 | ||||
-rw-r--r-- | Documentation/watchdog/watchdog.txt | 94 | ||||
-rw-r--r-- | Documentation/watchdog/wdt.txt | 43 |
4 files changed, 60 insertions, 321 deletions
diff --git a/Documentation/watchdog/pcwd-watchdog.txt b/Documentation/watchdog/pcwd-watchdog.txt index d9ee6336c1d4..4f68052395c0 100644 --- a/Documentation/watchdog/pcwd-watchdog.txt +++ b/Documentation/watchdog/pcwd-watchdog.txt | |||
@@ -1,3 +1,5 @@ | |||
1 | Last reviewed: 10/05/2007 | ||
2 | |||
1 | Berkshire Products PC Watchdog Card | 3 | Berkshire Products PC Watchdog Card |
2 | Support for ISA Cards Revision A and C | 4 | Support for ISA Cards Revision A and C |
3 | Documentation and Driver by Ken Hollis <kenji@bitgate.com> | 5 | Documentation and Driver by Ken Hollis <kenji@bitgate.com> |
@@ -14,8 +16,8 @@ | |||
14 | 16 | ||
15 | The Watchdog Driver will automatically find your watchdog card, and will | 17 | The Watchdog Driver will automatically find your watchdog card, and will |
16 | attach a running driver for use with that card. After the watchdog | 18 | attach a running driver for use with that card. After the watchdog |
17 | drivers have initialized, you can then talk to the card using the PC | 19 | drivers have initialized, you can then talk to the card using a PC |
18 | Watchdog program, available from http://ftp.bitgate.com/pcwd/. | 20 | Watchdog program. |
19 | 21 | ||
20 | I suggest putting a "watchdog -d" before the beginning of an fsck, and | 22 | I suggest putting a "watchdog -d" before the beginning of an fsck, and |
21 | a "watchdog -e -t 1" immediately after the end of an fsck. (Remember | 23 | a "watchdog -e -t 1" immediately after the end of an fsck. (Remember |
@@ -62,5 +64,3 @@ | |||
62 | -- Ken Hollis | 64 | -- Ken Hollis |
63 | (kenji@bitgate.com) | 65 | (kenji@bitgate.com) |
64 | 66 | ||
65 | (This documentation may be out of date. Check | ||
66 | http://ftp.bitgate.com/pcwd/ for the absolute latest additions.) | ||
diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt index 8d16f6f3c4ec..bb7cb1d31ec7 100644 --- a/Documentation/watchdog/watchdog-api.txt +++ b/Documentation/watchdog/watchdog-api.txt | |||
@@ -1,3 +1,6 @@ | |||
1 | Last reviewed: 10/05/2007 | ||
2 | |||
3 | |||
1 | The Linux Watchdog driver API. | 4 | The Linux Watchdog driver API. |
2 | 5 | ||
3 | Copyright 2002 Christer Weingel <wingel@nano-system.com> | 6 | Copyright 2002 Christer Weingel <wingel@nano-system.com> |
@@ -22,7 +25,7 @@ the system. If userspace fails (RAM error, kernel bug, whatever), the | |||
22 | notifications cease to occur, and the hardware watchdog will reset the | 25 | notifications cease to occur, and the hardware watchdog will reset the |
23 | system (causing a reboot) after the timeout occurs. | 26 | system (causing a reboot) after the timeout occurs. |
24 | 27 | ||
25 | The Linux watchdog API is a rather AD hoc construction and different | 28 | The Linux watchdog API is a rather ad-hoc construction and different |
26 | drivers implement different, and sometimes incompatible, parts of it. | 29 | drivers implement different, and sometimes incompatible, parts of it. |
27 | This file is an attempt to document the existing usage and allow | 30 | This file is an attempt to document the existing usage and allow |
28 | future driver writers to use it as a reference. | 31 | future driver writers to use it as a reference. |
@@ -46,14 +49,16 @@ some of the drivers support the configuration option "Disable watchdog | |||
46 | shutdown on close", CONFIG_WATCHDOG_NOWAYOUT. If it is set to Y when | 49 | shutdown on close", CONFIG_WATCHDOG_NOWAYOUT. If it is set to Y when |
47 | compiling the kernel, there is no way of disabling the watchdog once | 50 | compiling the kernel, there is no way of disabling the watchdog once |
48 | it has been started. So, if the watchdog daemon crashes, the system | 51 | it has been started. So, if the watchdog daemon crashes, the system |
49 | will reboot after the timeout has passed. | 52 | will reboot after the timeout has passed. Watchdog devices also usually |
53 | support the nowayout module parameter so that this option can be controlled | ||
54 | at runtime. | ||
50 | 55 | ||
51 | Some other drivers will not disable the watchdog, unless a specific | 56 | Drivers will not disable the watchdog, unless a specific magic character 'V' |
52 | magic character 'V' has been sent /dev/watchdog just before closing | 57 | has been sent /dev/watchdog just before closing the file. If the userspace |
53 | the file. If the userspace daemon closes the file without sending | 58 | daemon closes the file without sending this special character, the driver |
54 | this special character, the driver will assume that the daemon (and | 59 | will assume that the daemon (and userspace in general) died, and will stop |
55 | userspace in general) died, and will stop pinging the watchdog without | 60 | pinging the watchdog without disabling it first. This will then cause a |
56 | disabling it first. This will then cause a reboot. | 61 | reboot if the watchdog is not re-opened in sufficient time. |
57 | 62 | ||
58 | The ioctl API: | 63 | The ioctl API: |
59 | 64 | ||
@@ -227,218 +232,3 @@ The following options are available: | |||
227 | 232 | ||
228 | [FIXME -- better explanations] | 233 | [FIXME -- better explanations] |
229 | 234 | ||
230 | Implementations in the current drivers in the kernel tree: | ||
231 | |||
232 | Here I have tried to summarize what the different drivers support and | ||
233 | where they do strange things compared to the other drivers. | ||
234 | |||
235 | acquirewdt.c -- Acquire Single Board Computer | ||
236 | |||
237 | This driver has a hardcoded timeout of 1 minute | ||
238 | |||
239 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
240 | |||
241 | GETSUPPORT returns KEEPALIVEPING. GETSTATUS will return 1 if | ||
242 | the device is open, 0 if not. [FIXME -- isn't this rather | ||
243 | silly? To be able to use the ioctl, the device must be open | ||
244 | and so GETSTATUS will always return 1]. | ||
245 | |||
246 | advantechwdt.c -- Advantech Single Board Computer | ||
247 | |||
248 | Timeout that defaults to 60 seconds, supports SETTIMEOUT. | ||
249 | |||
250 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
251 | |||
252 | GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. | ||
253 | The GETSTATUS call returns if the device is open or not. | ||
254 | [FIXME -- silliness again?] | ||
255 | |||
256 | booke_wdt.c -- PowerPC BookE Watchdog Timer | ||
257 | |||
258 | Timeout default varies according to frequency, supports | ||
259 | SETTIMEOUT | ||
260 | |||
261 | Watchdog cannot be turned off, CONFIG_WATCHDOG_NOWAYOUT | ||
262 | does not make sense | ||
263 | |||
264 | GETSUPPORT returns the watchdog_info struct, and | ||
265 | GETSTATUS returns the supported options. GETBOOTSTATUS | ||
266 | returns a 1 if the last reset was caused by the | ||
267 | watchdog and a 0 otherwise. This watchdog cannot be | ||
268 | disabled once it has been started. The wdt_period kernel | ||
269 | parameter selects which bit of the time base changing | ||
270 | from 0->1 will trigger the watchdog exception. Changing | ||
271 | the timeout from the ioctl calls will change the | ||
272 | wdt_period as defined above. Finally if you would like to | ||
273 | replace the default Watchdog Handler you can implement the | ||
274 | WatchdogHandler() function in your own code. | ||
275 | |||
276 | eurotechwdt.c -- Eurotech CPU-1220/1410 | ||
277 | |||
278 | The timeout can be set using the SETTIMEOUT ioctl and defaults | ||
279 | to 60 seconds. | ||
280 | |||
281 | Also has a module parameter "ev", event type which controls | ||
282 | what should happen on a timeout, the string "int" or anything | ||
283 | else that causes a reboot. [FIXME -- better description] | ||
284 | |||
285 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
286 | |||
287 | GETSUPPORT returns CARDRESET and WDIOF_SETTIMEOUT but | ||
288 | GETSTATUS is not supported and GETBOOTSTATUS just returns 0. | ||
289 | |||
290 | i810-tco.c -- Intel 810 chipset | ||
291 | |||
292 | Also has support for a lot of other i8x0 stuff, but the | ||
293 | watchdog is one of the things. | ||
294 | |||
295 | The timeout is set using the module parameter "i810_margin", | ||
296 | which is in steps of 0.6 seconds where 2<i810_margin<64. The | ||
297 | driver supports the SETTIMEOUT ioctl. | ||
298 | |||
299 | Supports CONFIG_WATCHDOG_NOWAYOUT. | ||
300 | |||
301 | GETSUPPORT returns WDIOF_SETTIMEOUT. The GETSTATUS call | ||
302 | returns some kind of timer value which ist not compatible with | ||
303 | the other drivers. GETBOOT status returns some kind of | ||
304 | hardware specific boot status. [FIXME -- describe this] | ||
305 | |||
306 | ib700wdt.c -- IB700 Single Board Computer | ||
307 | |||
308 | Default timeout of 30 seconds and the timeout is settable | ||
309 | using the SETTIMEOUT ioctl. Note that only a few timeout | ||
310 | values are supported. | ||
311 | |||
312 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
313 | |||
314 | GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. | ||
315 | The GETSTATUS call returns if the device is open or not. | ||
316 | [FIXME -- silliness again?] | ||
317 | |||
318 | machzwd.c -- MachZ ZF-Logic | ||
319 | |||
320 | Hardcoded timeout of 10 seconds | ||
321 | |||
322 | Has a module parameter "action" that controls what happens | ||
323 | when the timeout runs out which can be 0 = RESET (default), | ||
324 | 1 = SMI, 2 = NMI, 3 = SCI. | ||
325 | |||
326 | Supports CONFIG_WATCHDOG_NOWAYOUT and the magic character | ||
327 | 'V' close handling. | ||
328 | |||
329 | GETSUPPORT returns WDIOF_KEEPALIVEPING, and the GETSTATUS call | ||
330 | returns if the device is open or not. [FIXME -- silliness | ||
331 | again?] | ||
332 | |||
333 | mixcomwd.c -- MixCom Watchdog | ||
334 | |||
335 | [FIXME -- I'm unable to tell what the timeout is] | ||
336 | |||
337 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
338 | |||
339 | GETSUPPORT returns WDIOF_KEEPALIVEPING, GETSTATUS returns if | ||
340 | the device is opened or not [FIXME -- I'm not really sure how | ||
341 | this works, there seems to be some magic connected to | ||
342 | CONFIG_WATCHDOG_NOWAYOUT] | ||
343 | |||
344 | pcwd.c -- Berkshire PC Watchdog | ||
345 | |||
346 | Hardcoded timeout of 1.5 seconds | ||
347 | |||
348 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
349 | |||
350 | GETSUPPORT returns WDIOF_OVERHEAT|WDIOF_CARDRESET and both | ||
351 | GETSTATUS and GETBOOTSTATUS return something useful. | ||
352 | |||
353 | The SETOPTIONS call can be used to enable and disable the card | ||
354 | and to ask the driver to call panic if the system overheats. | ||
355 | |||
356 | sbc60xxwdt.c -- 60xx Single Board Computer | ||
357 | |||
358 | Hardcoded timeout of 10 seconds | ||
359 | |||
360 | Does not support CONFIG_WATCHDOG_NOWAYOUT, but has the magic | ||
361 | character 'V' close handling. | ||
362 | |||
363 | No bits set in GETSUPPORT | ||
364 | |||
365 | scx200.c -- National SCx200 CPUs | ||
366 | |||
367 | Not in the kernel yet. | ||
368 | |||
369 | The timeout is set using a module parameter "margin" which | ||
370 | defaults to 60 seconds. The timeout can also be set using | ||
371 | SETTIMEOUT and read using GETTIMEOUT. | ||
372 | |||
373 | Supports a module parameter "nowayout" that is initialized | ||
374 | with the value of CONFIG_WATCHDOG_NOWAYOUT. Also supports the | ||
375 | magic character 'V' handling. | ||
376 | |||
377 | shwdt.c -- SuperH 3/4 processors | ||
378 | |||
379 | [FIXME -- I'm unable to tell what the timeout is] | ||
380 | |||
381 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
382 | |||
383 | GETSUPPORT returns WDIOF_KEEPALIVEPING, and the GETSTATUS call | ||
384 | returns if the device is open or not. [FIXME -- silliness | ||
385 | again?] | ||
386 | |||
387 | softdog.c -- Software watchdog | ||
388 | |||
389 | The timeout is set with the module parameter "soft_margin" | ||
390 | which defaults to 60 seconds, the timeout is also settable | ||
391 | using the SETTIMEOUT ioctl. | ||
392 | |||
393 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
394 | |||
395 | WDIOF_SETTIMEOUT bit set in GETSUPPORT | ||
396 | |||
397 | w83877f_wdt.c -- W83877F Computer | ||
398 | |||
399 | Hardcoded timeout of 30 seconds | ||
400 | |||
401 | Does not support CONFIG_WATCHDOG_NOWAYOUT, but has the magic | ||
402 | character 'V' close handling. | ||
403 | |||
404 | No bits set in GETSUPPORT | ||
405 | |||
406 | w83627hf_wdt.c -- w83627hf watchdog | ||
407 | |||
408 | Timeout that defaults to 60 seconds, supports SETTIMEOUT. | ||
409 | |||
410 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
411 | |||
412 | GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. | ||
413 | The GETSTATUS call returns if the device is open or not. | ||
414 | |||
415 | wdt.c -- ICS WDT500/501 ISA and | ||
416 | wdt_pci.c -- ICS WDT500/501 PCI | ||
417 | |||
418 | Default timeout of 60 seconds. The timeout is also settable | ||
419 | using the SETTIMEOUT ioctl. | ||
420 | |||
421 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
422 | |||
423 | GETSUPPORT returns with bits set depending on the actual | ||
424 | card. The WDT501 supports a lot of external monitoring, the | ||
425 | WDT500 much less. | ||
426 | |||
427 | wdt285.c -- Footbridge watchdog | ||
428 | |||
429 | The timeout is set with the module parameter "soft_margin" | ||
430 | which defaults to 60 seconds. The timeout is also settable | ||
431 | using the SETTIMEOUT ioctl. | ||
432 | |||
433 | Does not support CONFIG_WATCHDOG_NOWAYOUT | ||
434 | |||
435 | WDIOF_SETTIMEOUT bit set in GETSUPPORT | ||
436 | |||
437 | wdt977.c -- Netwinder W83977AF chip | ||
438 | |||
439 | Hardcoded timeout of 3 minutes | ||
440 | |||
441 | Supports CONFIG_WATCHDOG_NOWAYOUT | ||
442 | |||
443 | Does not support any ioctls at all. | ||
444 | |||
diff --git a/Documentation/watchdog/watchdog.txt b/Documentation/watchdog/watchdog.txt deleted file mode 100644 index 4b1ff69cc19a..000000000000 --- a/Documentation/watchdog/watchdog.txt +++ /dev/null | |||
@@ -1,94 +0,0 @@ | |||
1 | Watchdog Timer Interfaces For The Linux Operating System | ||
2 | |||
3 | Alan Cox <alan@lxorguk.ukuu.org.uk> | ||
4 | |||
5 | Custom Linux Driver And Program Development | ||
6 | |||
7 | |||
8 | The following watchdog drivers are currently implemented: | ||
9 | |||
10 | ICS WDT501-P | ||
11 | ICS WDT501-P (no fan tachometer) | ||
12 | ICS WDT500-P | ||
13 | Software Only | ||
14 | SA1100 Internal Watchdog | ||
15 | Berkshire Products PC Watchdog Revision A & C (by Ken Hollis) | ||
16 | |||
17 | |||
18 | All six interfaces provide /dev/watchdog, which when open must be written | ||
19 | to within a timeout or the machine will reboot. Each write delays the reboot | ||
20 | time another timeout. In the case of the software watchdog the ability to | ||
21 | reboot will depend on the state of the machines and interrupts. The hardware | ||
22 | boards physically pull the machine down off their own onboard timers and | ||
23 | will reboot from almost anything. | ||
24 | |||
25 | A second temperature monitoring interface is available on the WDT501P cards | ||
26 | and some Berkshire cards. This provides /dev/temperature. This is the machine | ||
27 | internal temperature in degrees Fahrenheit. Each read returns a single byte | ||
28 | giving the temperature. | ||
29 | |||
30 | The third interface logs kernel messages on additional alert events. | ||
31 | |||
32 | Both software and hardware watchdog drivers are available in the standard | ||
33 | kernel. If you are using the software watchdog, you probably also want | ||
34 | to use "panic=60" as a boot argument as well. | ||
35 | |||
36 | The wdt card cannot be safely probed for. Instead you need to pass | ||
37 | wdt=ioaddr,irq as a boot parameter - eg "wdt=0x240,11". | ||
38 | |||
39 | The SA1100 watchdog module can be configured with the "sa1100_margin" | ||
40 | commandline argument which specifies timeout value in seconds. | ||
41 | |||
42 | The i810 TCO watchdog modules can be configured with the "i810_margin" | ||
43 | commandline argument which specifies the counter initial value. The counter | ||
44 | is decremented every 0.6 seconds and default to 50 (30 seconds). Values can | ||
45 | range between 3 and 63. | ||
46 | |||
47 | The i810 TCO watchdog driver also implements the WDIOC_GETSTATUS and | ||
48 | WDIOC_GETBOOTSTATUS ioctl()s. WDIOC_GETSTATUS returns the actual counter value | ||
49 | and WDIOC_GETBOOTSTATUS returns the value of TCO2 Status Register (see Intel's | ||
50 | documentation for the 82801AA and 82801AB datasheet). | ||
51 | |||
52 | Features | ||
53 | -------- | ||
54 | WDT501P WDT500P Software Berkshire i810 TCO SA1100WD | ||
55 | Reboot Timer X X X X X X | ||
56 | External Reboot X X o o o X | ||
57 | I/O Port Monitor o o o X o o | ||
58 | Temperature X o o X o o | ||
59 | Fan Speed X o o o o o | ||
60 | Power Under X o o o o o | ||
61 | Power Over X o o o o o | ||
62 | Overheat X o o o o o | ||
63 | |||
64 | The external event interfaces on the WDT boards are not currently supported. | ||
65 | Minor numbers are however allocated for it. | ||
66 | |||
67 | |||
68 | Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c | ||
69 | |||
70 | |||
71 | Contact Information | ||
72 | |||
73 | People keep asking about the WDT watchdog timer hardware: The phone contacts | ||
74 | for Industrial Computer Source are: | ||
75 | |||
76 | Industrial Computer Source | ||
77 | http://www.indcompsrc.com | ||
78 | ICS Advent, San Diego | ||
79 | 6260 Sequence Dr. | ||
80 | San Diego, CA 92121-4371 | ||
81 | Phone (858) 677-0877 | ||
82 | FAX: (858) 677-0895 | ||
83 | > | ||
84 | ICS Advent Europe, UK | ||
85 | Oving Road | ||
86 | Chichester, | ||
87 | West Sussex, | ||
88 | PO19 4ET, UK | ||
89 | Phone: 00.44.1243.533900 | ||
90 | |||
91 | |||
92 | and please mention Linux when enquiring. | ||
93 | |||
94 | For full information about the PCWD cards see the pcwd-watchdog.txt document. | ||
diff --git a/Documentation/watchdog/wdt.txt b/Documentation/watchdog/wdt.txt new file mode 100644 index 000000000000..03fd756d976d --- /dev/null +++ b/Documentation/watchdog/wdt.txt | |||
@@ -0,0 +1,43 @@ | |||
1 | Last Reviewed: 10/05/2007 | ||
2 | |||
3 | WDT Watchdog Timer Interfaces For The Linux Operating System | ||
4 | Alan Cox <alan@lxorguk.ukuu.org.uk> | ||
5 | |||
6 | ICS WDT501-P | ||
7 | ICS WDT501-P (no fan tachometer) | ||
8 | ICS WDT500-P | ||
9 | |||
10 | All the interfaces provide /dev/watchdog, which when open must be written | ||
11 | to within a timeout or the machine will reboot. Each write delays the reboot | ||
12 | time another timeout. In the case of the software watchdog the ability to | ||
13 | reboot will depend on the state of the machines and interrupts. The hardware | ||
14 | boards physically pull the machine down off their own onboard timers and | ||
15 | will reboot from almost anything. | ||
16 | |||
17 | A second temperature monitoring interface is available on the WDT501P cards | ||
18 | This provides /dev/temperature. This is the machine internal temperature in | ||
19 | degrees Fahrenheit. Each read returns a single byte giving the temperature. | ||
20 | |||
21 | The third interface logs kernel messages on additional alert events. | ||
22 | |||
23 | The wdt card cannot be safely probed for. Instead you need to pass | ||
24 | wdt=ioaddr,irq as a boot parameter - eg "wdt=0x240,11". | ||
25 | |||
26 | Features | ||
27 | -------- | ||
28 | WDT501P WDT500P | ||
29 | Reboot Timer X X | ||
30 | External Reboot X X | ||
31 | I/O Port Monitor o o | ||
32 | Temperature X o | ||
33 | Fan Speed X o | ||
34 | Power Under X o | ||
35 | Power Over X o | ||
36 | Overheat X o | ||
37 | |||
38 | The external event interfaces on the WDT boards are not currently supported. | ||
39 | Minor numbers are however allocated for it. | ||
40 | |||
41 | |||
42 | Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c | ||
43 | |||