+4 -4

Documentation/watchdog/pcwd-watchdog.txt

reviewed

··· 1 1 + Last reviewed: 10/05/2007 2 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 19 - drivers have initialized, you can then talk to the card using the PC 20 20 - Watchdog program, available from http://ftp.bitgate.com/pcwd/. 17 17 + drivers have initialized, you can then talk to the card using a PC 18 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 (Remember ··· 64 62 -- Ken Hollis 65 63 (kenji@bitgate.com) 66 64 67 67 - (This documentation may be out of date. Check 68 68 - http://ftp.bitgate.com/pcwd/ for the absolute latest additions.)

+13 -223

Documentation/watchdog/watchdog-api.txt

reviewed

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

-94

Documentation/watchdog/watchdog.txt

reviewed

··· 1 1 - Watchdog Timer Interfaces For The Linux Operating System 2 2 - 3 3 - Alan Cox <alan@lxorguk.ukuu.org.uk> 4 4 - 5 5 - Custom Linux Driver And Program Development 6 6 - 7 7 - 8 8 - The following watchdog drivers are currently implemented: 9 9 - 10 10 - ICS WDT501-P 11 11 - ICS WDT501-P (no fan tachometer) 12 12 - ICS WDT500-P 13 13 - Software Only 14 14 - SA1100 Internal Watchdog 15 15 - Berkshire Products PC Watchdog Revision A & C (by Ken Hollis) 16 16 - 17 17 - 18 18 - All six interfaces provide /dev/watchdog, which when open must be written 19 19 - to within a timeout or the machine will reboot. Each write delays the reboot 20 20 - time another timeout. In the case of the software watchdog the ability to 21 21 - reboot will depend on the state of the machines and interrupts. The hardware 22 22 - boards physically pull the machine down off their own onboard timers and 23 23 - will reboot from almost anything. 24 24 - 25 25 - A second temperature monitoring interface is available on the WDT501P cards 26 26 - and some Berkshire cards. This provides /dev/temperature. This is the machine 27 27 - internal temperature in degrees Fahrenheit. Each read returns a single byte 28 28 - giving the temperature. 29 29 - 30 30 - The third interface logs kernel messages on additional alert events. 31 31 - 32 32 - Both software and hardware watchdog drivers are available in the standard 33 33 - kernel. If you are using the software watchdog, you probably also want 34 34 - to use "panic=60" as a boot argument as well. 35 35 - 36 36 - The wdt card cannot be safely probed for. Instead you need to pass 37 37 - wdt=ioaddr,irq as a boot parameter - eg "wdt=0x240,11". 38 38 - 39 39 - The SA1100 watchdog module can be configured with the "sa1100_margin" 40 40 - commandline argument which specifies timeout value in seconds. 41 41 - 42 42 - The i810 TCO watchdog modules can be configured with the "i810_margin" 43 43 - commandline argument which specifies the counter initial value. The counter 44 44 - is decremented every 0.6 seconds and default to 50 (30 seconds). Values can 45 45 - range between 3 and 63. 46 46 - 47 47 - The i810 TCO watchdog driver also implements the WDIOC_GETSTATUS and 48 48 - WDIOC_GETBOOTSTATUS ioctl()s. WDIOC_GETSTATUS returns the actual counter value 49 49 - and WDIOC_GETBOOTSTATUS returns the value of TCO2 Status Register (see Intel's 50 50 - documentation for the 82801AA and 82801AB datasheet). 51 51 - 52 52 - Features 53 53 - -------- 54 54 - WDT501P WDT500P Software Berkshire i810 TCO SA1100WD 55 55 - Reboot Timer X X X X X X 56 56 - External Reboot X X o o o X 57 57 - I/O Port Monitor o o o X o o 58 58 - Temperature X o o X o o 59 59 - Fan Speed X o o o o o 60 60 - Power Under X o o o o o 61 61 - Power Over X o o o o o 62 62 - Overheat X o o o o o 63 63 - 64 64 - The external event interfaces on the WDT boards are not currently supported. 65 65 - Minor numbers are however allocated for it. 66 66 - 67 67 - 68 68 - Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c 69 69 - 70 70 - 71 71 - Contact Information 72 72 - 73 73 - People keep asking about the WDT watchdog timer hardware: The phone contacts 74 74 - for Industrial Computer Source are: 75 75 - 76 76 - Industrial Computer Source 77 77 - http://www.indcompsrc.com 78 78 - ICS Advent, San Diego 79 79 - 6260 Sequence Dr. 80 80 - San Diego, CA 92121-4371 81 81 - Phone (858) 677-0877 82 82 - FAX: (858) 677-0895 83 83 - > 84 84 - ICS Advent Europe, UK 85 85 - Oving Road 86 86 - Chichester, 87 87 - West Sussex, 88 88 - PO19 4ET, UK 89 89 - Phone: 00.44.1243.533900 90 90 - 91 91 - 92 92 - and please mention Linux when enquiring. 93 93 - 94 94 - For full information about the PCWD cards see the pcwd-watchdog.txt document.

+43

Documentation/watchdog/wdt.txt

reviewed

··· 1 1 + Last Reviewed: 10/05/2007 2 2 + 3 3 + WDT Watchdog Timer Interfaces For The Linux Operating System 4 4 + Alan Cox <alan@lxorguk.ukuu.org.uk> 5 5 + 6 6 + ICS WDT501-P 7 7 + ICS WDT501-P (no fan tachometer) 8 8 + ICS WDT500-P 9 9 + 10 10 + All the interfaces provide /dev/watchdog, which when open must be written 11 11 + to within a timeout or the machine will reboot. Each write delays the reboot 12 12 + time another timeout. In the case of the software watchdog the ability to 13 13 + reboot will depend on the state of the machines and interrupts. The hardware 14 14 + boards physically pull the machine down off their own onboard timers and 15 15 + will reboot from almost anything. 16 16 + 17 17 + A second temperature monitoring interface is available on the WDT501P cards 18 18 + This provides /dev/temperature. This is the machine internal temperature in 19 19 + degrees Fahrenheit. Each read returns a single byte giving the temperature. 20 20 + 21 21 + The third interface logs kernel messages on additional alert events. 22 22 + 23 23 + The wdt card cannot be safely probed for. Instead you need to pass 24 24 + wdt=ioaddr,irq as a boot parameter - eg "wdt=0x240,11". 25 25 + 26 26 + Features 27 27 + -------- 28 28 + WDT501P WDT500P 29 29 + Reboot Timer X X 30 30 + External Reboot X X 31 31 + I/O Port Monitor o o 32 32 + Temperature X o 33 33 + Fan Speed X o 34 34 + Power Under X o 35 35 + Power Over X o 36 36 + Overheat X o 37 37 + 38 38 + The external event interfaces on the WDT boards are not currently supported. 39 39 + Minor numbers are however allocated for it. 40 40 + 41 41 + 42 42 + Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c 43 43 +

+7

drivers/char/watchdog/Kconfig

reviewed

··· 115 115 116 116 Say N if you are unsure. 117 117 118 118 + config KS8695_WATCHDOG 119 119 + tristate "KS8695 watchdog" 120 120 + depends on ARCH_KS8695 121 121 + help 122 122 + Watchdog timer embedded into KS8695 processor. This will reboot your 123 123 + system when the timeout is reached. 124 124 + 118 125 config S3C2410_WATCHDOG 119 126 tristate "S3C2410 Watchdog" 120 127 depends on ARCH_S3C2410

+1

drivers/char/watchdog/Makefile

reviewed

··· 29 29 obj-$(CONFIG_977_WATCHDOG) += wdt977.o 30 30 obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o 31 31 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o 32 32 + obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o 32 33 obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o 33 34 obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o 34 35 obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o

+308

drivers/char/watchdog/ks8695_wdt.c

reviewed

··· 1 1 + /* 2 2 + * Watchdog driver for Kendin/Micrel KS8695. 3 3 + * 4 4 + * (C) 2007 Andrew Victor 5 5 + * 6 6 + * This program is free software; you can redistribute it and/or modify 7 7 + * it under the terms of the GNU General Public License version 2 as 8 8 + * published by the Free Software Foundation. 9 9 + */ 10 10 + 11 11 + #include <linux/errno.h> 12 12 + #include <linux/fs.h> 13 13 + #include <linux/init.h> 14 14 + #include <linux/kernel.h> 15 15 + #include <linux/miscdevice.h> 16 16 + #include <linux/module.h> 17 17 + #include <linux/moduleparam.h> 18 18 + #include <linux/platform_device.h> 19 19 + #include <linux/types.h> 20 20 + #include <linux/watchdog.h> 21 21 + #include <asm/bitops.h> 22 22 + #include <asm/io.h> 23 23 + #include <asm/uaccess.h> 24 24 + #include <asm/arch/regs-timer.h> 25 25 + 26 26 + 27 27 + #define WDT_DEFAULT_TIME 5 /* seconds */ 28 28 + #define WDT_MAX_TIME 171 /* seconds */ 29 29 + 30 30 + static int wdt_time = WDT_DEFAULT_TIME; 31 31 + static int nowayout = WATCHDOG_NOWAYOUT; 32 32 + 33 33 + module_param(wdt_time, int, 0); 34 34 + MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")"); 35 35 + 36 36 + #ifdef CONFIG_WATCHDOG_NOWAYOUT 37 37 + module_param(nowayout, int, 0); 38 38 + MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 39 39 + #endif 40 40 + 41 41 + 42 42 + static unsigned long ks8695wdt_busy; 43 43 + 44 44 + /* ......................................................................... */ 45 45 + 46 46 + /* 47 47 + * Disable the watchdog. 48 48 + */ 49 49 + static void inline ks8695_wdt_stop(void) 50 50 + { 51 51 + unsigned long tmcon; 52 52 + 53 53 + /* disable timer0 */ 54 54 + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); 55 55 + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); 56 56 + } 57 57 + 58 58 + /* 59 59 + * Enable and reset the watchdog. 60 60 + */ 61 61 + static void inline ks8695_wdt_start(void) 62 62 + { 63 63 + unsigned long tmcon; 64 64 + unsigned long tval = wdt_time * CLOCK_TICK_RATE; 65 65 + 66 66 + /* disable timer0 */ 67 67 + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); 68 68 + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); 69 69 + 70 70 + /* program timer0 */ 71 71 + __raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC); 72 72 + 73 73 + /* re-enable timer0 */ 74 74 + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); 75 75 + __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); 76 76 + } 77 77 + 78 78 + /* 79 79 + * Reload the watchdog timer. (ie, pat the watchdog) 80 80 + */ 81 81 + static void inline ks8695_wdt_reload(void) 82 82 + { 83 83 + unsigned long tmcon; 84 84 + 85 85 + /* disable, then re-enable timer0 */ 86 86 + tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); 87 87 + __raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); 88 88 + __raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); 89 89 + } 90 90 + 91 91 + /* 92 92 + * Change the watchdog time interval. 93 93 + */ 94 94 + static int ks8695_wdt_settimeout(int new_time) 95 95 + { 96 96 + /* 97 97 + * All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz 98 98 + * 99 99 + * Since WDV is a 16-bit counter, the maximum period is 100 100 + * 65536 / 0.256 = 256 seconds. 101 101 + */ 102 102 + if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) 103 103 + return -EINVAL; 104 104 + 105 105 + /* Set new watchdog time. It will be used when ks8695_wdt_start() is called. */ 106 106 + wdt_time = new_time; 107 107 + return 0; 108 108 + } 109 109 + 110 110 + /* ......................................................................... */ 111 111 + 112 112 + /* 113 113 + * Watchdog device is opened, and watchdog starts running. 114 114 + */ 115 115 + static int ks8695_wdt_open(struct inode *inode, struct file *file) 116 116 + { 117 117 + if (test_and_set_bit(0, &ks8695wdt_busy)) 118 118 + return -EBUSY; 119 119 + 120 120 + ks8695_wdt_start(); 121 121 + return nonseekable_open(inode, file); 122 122 + } 123 123 + 124 124 + /* 125 125 + * Close the watchdog device. 126 126 + * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also 127 127 + * disabled. 128 128 + */ 129 129 + static int ks8695_wdt_close(struct inode *inode, struct file *file) 130 130 + { 131 131 + if (!nowayout) 132 132 + ks8695_wdt_stop(); /* Disable the watchdog when file is closed */ 133 133 + 134 134 + clear_bit(0, &ks8695wdt_busy); 135 135 + return 0; 136 136 + } 137 137 + 138 138 + static struct watchdog_info ks8695_wdt_info = { 139 139 + .identity = "ks8695 watchdog", 140 140 + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 141 141 + }; 142 142 + 143 143 + /* 144 144 + * Handle commands from user-space. 145 145 + */ 146 146 + static int ks8695_wdt_ioctl(struct inode *inode, struct file *file, 147 147 + unsigned int cmd, unsigned long arg) 148 148 + { 149 149 + void __user *argp = (void __user *)arg; 150 150 + int __user *p = argp; 151 151 + int new_value; 152 152 + 153 153 + switch(cmd) { 154 154 + case WDIOC_KEEPALIVE: 155 155 + ks8695_wdt_reload(); /* pat the watchdog */ 156 156 + return 0; 157 157 + 158 158 + case WDIOC_GETSUPPORT: 159 159 + return copy_to_user(argp, &ks8695_wdt_info, sizeof(ks8695_wdt_info)) ? -EFAULT : 0; 160 160 + 161 161 + case WDIOC_SETTIMEOUT: 162 162 + if (get_user(new_value, p)) 163 163 + return -EFAULT; 164 164 + 165 165 + if (ks8695_wdt_settimeout(new_value)) 166 166 + return -EINVAL; 167 167 + 168 168 + /* Enable new time value */ 169 169 + ks8695_wdt_start(); 170 170 + 171 171 + /* Return current value */ 172 172 + return put_user(wdt_time, p); 173 173 + 174 174 + case WDIOC_GETTIMEOUT: 175 175 + return put_user(wdt_time, p); 176 176 + 177 177 + case WDIOC_GETSTATUS: 178 178 + case WDIOC_GETBOOTSTATUS: 179 179 + return put_user(0, p); 180 180 + 181 181 + case WDIOC_SETOPTIONS: 182 182 + if (get_user(new_value, p)) 183 183 + return -EFAULT; 184 184 + 185 185 + if (new_value & WDIOS_DISABLECARD) 186 186 + ks8695_wdt_stop(); 187 187 + if (new_value & WDIOS_ENABLECARD) 188 188 + ks8695_wdt_start(); 189 189 + return 0; 190 190 + 191 191 + default: 192 192 + return -ENOTTY; 193 193 + } 194 194 + } 195 195 + 196 196 + /* 197 197 + * Pat the watchdog whenever device is written to. 198 198 + */ 199 199 + static ssize_t ks8695_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) 200 200 + { 201 201 + ks8695_wdt_reload(); /* pat the watchdog */ 202 202 + return len; 203 203 + } 204 204 + 205 205 + /* ......................................................................... */ 206 206 + 207 207 + static const struct file_operations ks8695wdt_fops = { 208 208 + .owner = THIS_MODULE, 209 209 + .llseek = no_llseek, 210 210 + .ioctl = ks8695_wdt_ioctl, 211 211 + .open = ks8695_wdt_open, 212 212 + .release = ks8695_wdt_close, 213 213 + .write = ks8695_wdt_write, 214 214 + }; 215 215 + 216 216 + static struct miscdevice ks8695wdt_miscdev = { 217 217 + .minor = WATCHDOG_MINOR, 218 218 + .name = "watchdog", 219 219 + .fops = &ks8695wdt_fops, 220 220 + }; 221 221 + 222 222 + static int __init ks8695wdt_probe(struct platform_device *pdev) 223 223 + { 224 224 + int res; 225 225 + 226 226 + if (ks8695wdt_miscdev.parent) 227 227 + return -EBUSY; 228 228 + ks8695wdt_miscdev.parent = &pdev->dev; 229 229 + 230 230 + res = misc_register(&ks8695wdt_miscdev); 231 231 + if (res) 232 232 + return res; 233 233 + 234 234 + printk("KS8695 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : ""); 235 235 + return 0; 236 236 + } 237 237 + 238 238 + static int __exit ks8695wdt_remove(struct platform_device *pdev) 239 239 + { 240 240 + int res; 241 241 + 242 242 + res = misc_deregister(&ks8695wdt_miscdev); 243 243 + if (!res) 244 244 + ks8695wdt_miscdev.parent = NULL; 245 245 + 246 246 + return res; 247 247 + } 248 248 + 249 249 + static void ks8695wdt_shutdown(struct platform_device *pdev) 250 250 + { 251 251 + ks8695_wdt_stop(); 252 252 + } 253 253 + 254 254 + #ifdef CONFIG_PM 255 255 + 256 256 + static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message) 257 257 + { 258 258 + ks8695_wdt_stop(); 259 259 + return 0; 260 260 + } 261 261 + 262 262 + static int ks8695wdt_resume(struct platform_device *pdev) 263 263 + { 264 264 + if (ks8695wdt_busy) 265 265 + ks8695_wdt_start(); 266 266 + return 0; 267 267 + } 268 268 + 269 269 + #else 270 270 + #define ks8695wdt_suspend NULL 271 271 + #define ks8695wdt_resume NULL 272 272 + #endif 273 273 + 274 274 + static struct platform_driver ks8695wdt_driver = { 275 275 + .probe = ks8695wdt_probe, 276 276 + .remove = __exit_p(ks8695wdt_remove), 277 277 + .shutdown = ks8695wdt_shutdown, 278 278 + .suspend = ks8695wdt_suspend, 279 279 + .resume = ks8695wdt_resume, 280 280 + .driver = { 281 281 + .name = "ks8695_wdt", 282 282 + .owner = THIS_MODULE, 283 283 + }, 284 284 + }; 285 285 + 286 286 + static int __init ks8695_wdt_init(void) 287 287 + { 288 288 + /* Check that the heartbeat value is within range; if not reset to the default */ 289 289 + if (ks8695_wdt_settimeout(wdt_time)) { 290 290 + ks8695_wdt_settimeout(WDT_DEFAULT_TIME); 291 291 + pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i, using %d\n", wdt_time, WDT_MAX_TIME); 292 292 + } 293 293 + 294 294 + return platform_driver_register(&ks8695wdt_driver); 295 295 + } 296 296 + 297 297 + static void __exit ks8695_wdt_exit(void) 298 298 + { 299 299 + platform_driver_unregister(&ks8695wdt_driver); 300 300 + } 301 301 + 302 302 + module_init(ks8695_wdt_init); 303 303 + module_exit(ks8695_wdt_exit); 304 304 + 305 305 + MODULE_AUTHOR("Andrew Victor"); 306 306 + MODULE_DESCRIPTION("Watchdog driver for KS8695"); 307 307 + MODULE_LICENSE("GPL"); 308 308 + MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);