[PATCH] ppc32: Added support for the Book-E style Watchdog Timer

PowerPC 40x and Book-E processors support a watchdog timer at the processor
core level.  The timer has implementation dependent timeout frequencies
that can be configured by software.

One the first Watchdog timeout we get a critical exception.  It is left to
board specific code to determine what should happen at this point.  If
nothing is done and another timeout period expires the processor may
attempt to reset the machine.

Command line parameters:
  wdt=0 : disable watchdog (default)
  wdt=1 : enable watchdog

  wdt_period=N : N sets the value of the Watchdog Timer Period.

  The Watchdog Timer Period meaning is implementation specific. Check
  User Manual for the processor for more details.

This patch is based off of work done by Takeharu Kato.

Signed-off-by: Matt McClintock <msm@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Kumar Gala
2005-09-03 15:55:33 -07:00
committed by Linus Torvalds
parent 886b9fa499
commit a2f40ccd29
10 changed files with 270 additions and 27 deletions

View File

@@ -228,6 +228,26 @@ advantechwdt.c -- Advantech Single Board Computer
The GETSTATUS call returns if the device is open or not.
[FIXME -- silliness again?]
booke_wdt.c -- PowerPC BookE Watchdog Timer
Timeout default varies according to frequency, supports
SETTIMEOUT
Watchdog can not be turned off, CONFIG_WATCHDOG_NOWAYOUT
does not make sense
GETSUPPORT returns the watchdog_info struct, and
GETSTATUS returns the supported options. GETBOOTSTATUS
returns a 1 if the last reset was caused by the
watchdog and a 0 otherwise. This watchdog can not be
disabled once it has been started. The wdt_period kernel
parameter selects which bit of the time base changing
from 0->1 will trigger the watchdog exception. Changing
the timeout from the ioctl calls will change the
wdt_period as defined above. Finally if you would like to
replace the default Watchdog Handler you can implement the
WatchdogHandler() function in your own code.
eurotechwdt.c -- Eurotech CPU-1220/1410
The timeout can be set using the SETTIMEOUT ioctl and defaults