[WATCHDOG] mpc8xxx_wdt: add support for MPC8xx watchdogs

The mpc8xxx_wdt driver is using two registers: SWSRR to push magic
numbers, and SWCRR to control the watchdog.  Both registers are available
on the MPC8xx, and seem to have the same offsets and semantics as in
MPC83xx/MPC86xx watchdogs.  The only difference is prescale value.  So
this driver simply works on the MPC8xx CPUs.

One quirk is needed for the MPC8xx, though.  It has small prescale value
and slow CPU, so the watchdog resets board prior to the driver has time to
load.  To solve this we should split initialization in two steps: start
ping the watchdog early, and register the watchdog userspace interface
later.

MPC823 seem to be the first CPU in MPC8xx line, so we use fsl,mpc823-wdt
compatible matching.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Tested-by: Jochen Friedrich <jochen@scram.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 01e33e80eac0..50d44b4b466b 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -697,10 +697,11 @@ config 8xx_WDT
 
 config 8xxx_WDT
         tristate "MPC8xxx Platform Watchdog Timer"
-        depends on PPC_83xx || PPC_86xx
+        depends on PPC_8xx || PPC_83xx || PPC_86xx
         help
           This driver is for a SoC level watchdog that exists on some
           Freescale PowerPC processors. So far this driver supports:
+          - MPC8xx watchdogs
           - MPC83xx watchdogs
           - MPC86xx watchdogs