watchdog: Add Xilinx watchdog timer driver

Watchdog timer device driver for Xilinx xps_timebase_wdt compatible ip cores.
It takes watchdog timer configuration from device tree and it needs that its
parent has defined the property "clock-frecuency".
It is compatible with watchdog timer kernel API, so user apps like watchdogd
may talk with it.

Signed-off-by: Alejandro Cabrera <aldaya@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -888,6 +888,20 @@ config M54xx_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called m54xx_wdt.
 
+# MicroBlaze Architecture
+
+config XILINX_WATCHDOG
+	tristate "Xilinx Watchdog timer"
+	depends on MICROBLAZE
+	---help---
+	  Watchdog driver for the xps_timebase_wdt ip core.
+
+	  IMPORTANT: The xps_timebase_wdt parent must have the property
+	  "clock-frequency" at device tree.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called of_xilinx_wdt.
+
 # MIPS Architecture
 
 config ATH79_WDT

drivers/watchdog/Makefile

@@ -110,6 +110,9 @@ obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
 # M68K Architecture
 obj-$(CONFIG_M54xx_WATCHDOG) += m54xx_wdt.o
 
+# MicroBlaze Architecture
+obj-$(CONFIG_XILINX_WATCHDOG) += of_xilinx_wdt.o
+
 # MIPS Architecture
 obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
 obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o