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[WATCHDOG] clean-up watchdog documentation

Random sampling of some URLs in the Documentation tree to see how many were
stale found that one watchdog driver was now a porn site. In fact if the
watchdogs document directory was any older it would be written in latin

Clean it up somewhat and add Last reviewed headers, something all the
Documentation could do with IMHO.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

authored by Alan Cox and committed by Wim Van Sebroeck 4d389dce ccb8f430

+60 -321
unified split
+4 -4
Documentation/watchdog/pcwd-watchdog.txt
··· 1 + Last reviewed: 10/05/2007 2 + 1 3 Berkshire Products PC Watchdog Card 2 4 Support for ISA Cards Revision A and C 3 5 Documentation and Driver by Ken Hollis <kenji@bitgate.com> ··· 16 14 17 15 The Watchdog Driver will automatically find your watchdog card, and will 18 16 attach a running driver for use with that card. After the watchdog 19 - drivers have initialized, you can then talk to the card using the PC 20 - Watchdog program, available from http://ftp.bitgate.com/pcwd/. 17 + drivers have initialized, you can then talk to the card using a PC 18 + Watchdog program. 21 19 22 20 I suggest putting a "watchdog -d" before the beginning of an fsck, and 23 21 a "watchdog -e -t 1" immediately after the end of an fsck. (Remember ··· 64 62 -- Ken Hollis 65 63 (kenji@bitgate.com) 66 64 67 - (This documentation may be out of date. Check 68 - http://ftp.bitgate.com/pcwd/ for the absolute latest additions.)
+13 -223
Documentation/watchdog/watchdog-api.txt
··· 1 + Last reviewed: 10/05/2007 2 + 3 + 1 4 The Linux Watchdog driver API. 2 5 3 6 Copyright 2002 Christer Weingel <wingel@nano-system.com> ··· 25 22 notifications cease to occur, and the hardware watchdog will reset the 26 23 system (causing a reboot) after the timeout occurs. 27 24 28 - The Linux watchdog API is a rather AD hoc construction and different 25 + The Linux watchdog API is a rather ad-hoc construction and different 29 26 drivers implement different, and sometimes incompatible, parts of it. 30 27 This file is an attempt to document the existing usage and allow 31 28 future driver writers to use it as a reference. ··· 49 46 shutdown on close", CONFIG_WATCHDOG_NOWAYOUT. If it is set to Y when 50 47 compiling the kernel, there is no way of disabling the watchdog once 51 48 it has been started. So, if the watchdog daemon crashes, the system 52 - will reboot after the timeout has passed. 49 + will reboot after the timeout has passed. Watchdog devices also usually 50 + support the nowayout module parameter so that this option can be controlled 51 + at runtime. 53 52 54 - Some other drivers will not disable the watchdog, unless a specific 55 - magic character 'V' has been sent /dev/watchdog just before closing 56 - the file. If the userspace daemon closes the file without sending 57 - this special character, the driver will assume that the daemon (and 58 - userspace in general) died, and will stop pinging the watchdog without 59 - disabling it first. This will then cause a reboot. 53 + Drivers will not disable the watchdog, unless a specific magic character 'V' 54 + has been sent /dev/watchdog just before closing the file. If the userspace 55 + daemon closes the file without sending this special character, the driver 56 + will assume that the daemon (and userspace in general) died, and will stop 57 + pinging the watchdog without disabling it first. This will then cause a 58 + reboot if the watchdog is not re-opened in sufficient time. 60 59 61 60 The ioctl API: 62 61 ··· 231 226 WDIOS_TEMPPANIC Kernel panic on temperature trip 232 227 233 228 [FIXME -- better explanations] 234 - 235 - Implementations in the current drivers in the kernel tree: 236 - 237 - Here I have tried to summarize what the different drivers support and 238 - where they do strange things compared to the other drivers. 239 - 240 - acquirewdt.c -- Acquire Single Board Computer 241 - 242 - This driver has a hardcoded timeout of 1 minute 243 - 244 - Supports CONFIG_WATCHDOG_NOWAYOUT 245 - 246 - GETSUPPORT returns KEEPALIVEPING. GETSTATUS will return 1 if 247 - the device is open, 0 if not. [FIXME -- isn't this rather 248 - silly? To be able to use the ioctl, the device must be open 249 - and so GETSTATUS will always return 1]. 250 - 251 - advantechwdt.c -- Advantech Single Board Computer 252 - 253 - Timeout that defaults to 60 seconds, supports SETTIMEOUT. 254 - 255 - Supports CONFIG_WATCHDOG_NOWAYOUT 256 - 257 - GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. 258 - The GETSTATUS call returns if the device is open or not. 259 - [FIXME -- silliness again?] 260 - 261 - booke_wdt.c -- PowerPC BookE Watchdog Timer 262 - 263 - Timeout default varies according to frequency, supports 264 - SETTIMEOUT 265 - 266 - Watchdog cannot be turned off, CONFIG_WATCHDOG_NOWAYOUT 267 - does not make sense 268 - 269 - GETSUPPORT returns the watchdog_info struct, and 270 - GETSTATUS returns the supported options. GETBOOTSTATUS 271 - returns a 1 if the last reset was caused by the 272 - watchdog and a 0 otherwise. This watchdog cannot be 273 - disabled once it has been started. The wdt_period kernel 274 - parameter selects which bit of the time base changing 275 - from 0->1 will trigger the watchdog exception. Changing 276 - the timeout from the ioctl calls will change the 277 - wdt_period as defined above. Finally if you would like to 278 - replace the default Watchdog Handler you can implement the 279 - WatchdogHandler() function in your own code. 280 - 281 - eurotechwdt.c -- Eurotech CPU-1220/1410 282 - 283 - The timeout can be set using the SETTIMEOUT ioctl and defaults 284 - to 60 seconds. 285 - 286 - Also has a module parameter "ev", event type which controls 287 - what should happen on a timeout, the string "int" or anything 288 - else that causes a reboot. [FIXME -- better description] 289 - 290 - Supports CONFIG_WATCHDOG_NOWAYOUT 291 - 292 - GETSUPPORT returns CARDRESET and WDIOF_SETTIMEOUT but 293 - GETSTATUS is not supported and GETBOOTSTATUS just returns 0. 294 - 295 - i810-tco.c -- Intel 810 chipset 296 - 297 - Also has support for a lot of other i8x0 stuff, but the 298 - watchdog is one of the things. 299 - 300 - The timeout is set using the module parameter "i810_margin", 301 - which is in steps of 0.6 seconds where 2<i810_margin<64. The 302 - driver supports the SETTIMEOUT ioctl. 303 - 304 - Supports CONFIG_WATCHDOG_NOWAYOUT. 305 - 306 - GETSUPPORT returns WDIOF_SETTIMEOUT. The GETSTATUS call 307 - returns some kind of timer value which ist not compatible with 308 - the other drivers. GETBOOT status returns some kind of 309 - hardware specific boot status. [FIXME -- describe this] 310 - 311 - ib700wdt.c -- IB700 Single Board Computer 312 - 313 - Default timeout of 30 seconds and the timeout is settable 314 - using the SETTIMEOUT ioctl. Note that only a few timeout 315 - values are supported. 316 - 317 - Supports CONFIG_WATCHDOG_NOWAYOUT 318 - 319 - GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. 320 - The GETSTATUS call returns if the device is open or not. 321 - [FIXME -- silliness again?] 322 - 323 - machzwd.c -- MachZ ZF-Logic 324 - 325 - Hardcoded timeout of 10 seconds 326 - 327 - Has a module parameter "action" that controls what happens 328 - when the timeout runs out which can be 0 = RESET (default), 329 - 1 = SMI, 2 = NMI, 3 = SCI. 330 - 331 - Supports CONFIG_WATCHDOG_NOWAYOUT and the magic character 332 - 'V' close handling. 333 - 334 - GETSUPPORT returns WDIOF_KEEPALIVEPING, and the GETSTATUS call 335 - returns if the device is open or not. [FIXME -- silliness 336 - again?] 337 - 338 - mixcomwd.c -- MixCom Watchdog 339 - 340 - [FIXME -- I'm unable to tell what the timeout is] 341 - 342 - Supports CONFIG_WATCHDOG_NOWAYOUT 343 - 344 - GETSUPPORT returns WDIOF_KEEPALIVEPING, GETSTATUS returns if 345 - the device is opened or not [FIXME -- I'm not really sure how 346 - this works, there seems to be some magic connected to 347 - CONFIG_WATCHDOG_NOWAYOUT] 348 - 349 - pcwd.c -- Berkshire PC Watchdog 350 - 351 - Hardcoded timeout of 1.5 seconds 352 - 353 - Supports CONFIG_WATCHDOG_NOWAYOUT 354 - 355 - GETSUPPORT returns WDIOF_OVERHEAT|WDIOF_CARDRESET and both 356 - GETSTATUS and GETBOOTSTATUS return something useful. 357 - 358 - The SETOPTIONS call can be used to enable and disable the card 359 - and to ask the driver to call panic if the system overheats. 360 - 361 - sbc60xxwdt.c -- 60xx Single Board Computer 362 - 363 - Hardcoded timeout of 10 seconds 364 - 365 - Does not support CONFIG_WATCHDOG_NOWAYOUT, but has the magic 366 - character 'V' close handling. 367 - 368 - No bits set in GETSUPPORT 369 - 370 - scx200.c -- National SCx200 CPUs 371 - 372 - Not in the kernel yet. 373 - 374 - The timeout is set using a module parameter "margin" which 375 - defaults to 60 seconds. The timeout can also be set using 376 - SETTIMEOUT and read using GETTIMEOUT. 377 - 378 - Supports a module parameter "nowayout" that is initialized 379 - with the value of CONFIG_WATCHDOG_NOWAYOUT. Also supports the 380 - magic character 'V' handling. 381 - 382 - shwdt.c -- SuperH 3/4 processors 383 - 384 - [FIXME -- I'm unable to tell what the timeout is] 385 - 386 - Supports CONFIG_WATCHDOG_NOWAYOUT 387 - 388 - GETSUPPORT returns WDIOF_KEEPALIVEPING, and the GETSTATUS call 389 - returns if the device is open or not. [FIXME -- silliness 390 - again?] 391 - 392 - softdog.c -- Software watchdog 393 - 394 - The timeout is set with the module parameter "soft_margin" 395 - which defaults to 60 seconds, the timeout is also settable 396 - using the SETTIMEOUT ioctl. 397 - 398 - Supports CONFIG_WATCHDOG_NOWAYOUT 399 - 400 - WDIOF_SETTIMEOUT bit set in GETSUPPORT 401 - 402 - w83877f_wdt.c -- W83877F Computer 403 - 404 - Hardcoded timeout of 30 seconds 405 - 406 - Does not support CONFIG_WATCHDOG_NOWAYOUT, but has the magic 407 - character 'V' close handling. 408 - 409 - No bits set in GETSUPPORT 410 - 411 - w83627hf_wdt.c -- w83627hf watchdog 412 - 413 - Timeout that defaults to 60 seconds, supports SETTIMEOUT. 414 - 415 - Supports CONFIG_WATCHDOG_NOWAYOUT 416 - 417 - GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT. 418 - The GETSTATUS call returns if the device is open or not. 419 - 420 - wdt.c -- ICS WDT500/501 ISA and 421 - wdt_pci.c -- ICS WDT500/501 PCI 422 - 423 - Default timeout of 60 seconds. The timeout is also settable 424 - using the SETTIMEOUT ioctl. 425 - 426 - Supports CONFIG_WATCHDOG_NOWAYOUT 427 - 428 - GETSUPPORT returns with bits set depending on the actual 429 - card. The WDT501 supports a lot of external monitoring, the 430 - WDT500 much less. 431 - 432 - wdt285.c -- Footbridge watchdog 433 - 434 - The timeout is set with the module parameter "soft_margin" 435 - which defaults to 60 seconds. The timeout is also settable 436 - using the SETTIMEOUT ioctl. 437 - 438 - Does not support CONFIG_WATCHDOG_NOWAYOUT 439 - 440 - WDIOF_SETTIMEOUT bit set in GETSUPPORT 441 - 442 - wdt977.c -- Netwinder W83977AF chip 443 - 444 - Hardcoded timeout of 3 minutes 445 - 446 - Supports CONFIG_WATCHDOG_NOWAYOUT 447 - 448 - Does not support any ioctls at all. 449 229
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Documentation/watchdog/watchdog.txt
··· 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.
+43
Documentation/watchdog/wdt.txt
··· 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 +