powerpc/watchdog: Allow the Book-E driver to be compiled as a module

Register the __init and __exit functions in the PowerPC Book-E Watchdog
driver as module entry/exit functions, and modify the Kconfig entry.

Add a .release method for the PowerPC Book-E Watchdog driver, so that the
watchdog is disabled when the driver is closed.

Loosely based on original code from Jiang Yutang <b14898@freescale.com>.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 24efd8ea41bb..a6812eb31fa1 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -957,9 +957,12 @@ config PIKA_WDT
           the Warp platform.
 
 config BOOKE_WDT
-        bool "PowerPC Book-E Watchdog Timer"
+        tristate "PowerPC Book-E Watchdog Timer"
         depends on BOOKE || 4xx
         ---help---
+          Watchdog driver for PowerPC Book-E chips, such as the Freescale
+          MPC85xx SOCs and the IBM PowerPC 440.
+
           Please see Documentation/watchdog/watchdog-api.txt for
           more information.