[PATCH 11/12] watchdog: sp5100-tco: Abort if watchdog is disabled by hardware

[Guenter Roeck]

If the watchdog control register indicates that the watchdog hardware
is disabled even after we tried to enable it, there is no point to
instantiate the driver.

Cc: ZoltÃn BÃszÃrmÃnyi <zboszor@xxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
 drivers/watchdog/sp5100_tco.c | 8 +++++++-
 drivers/watchdog/sp5100_tco.h | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index bb6c4608c1c0..23246cb40598 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -273,14 +273,20 @@ static int sp5100_tco_setupdevice(struct device *dev,
 	/* Setup the watchdog timer */
 	tco_timer_enable();
 
-	/* Check that the watchdog action is set to reset the system */
 	val = readl(SP5100_WDT_CONTROL(tco->tcobase));
+	if (val & SP5100_WDT_DISABLED) {
+		dev_err(dev, "Watchdog hardware is disabled\n");
+		ret = -ENODEV;
+		goto unreg_region;
+	}
+
 	/*
 	 * Save WatchDogFired status, because WatchDogFired flag is
 	 * cleared here.
 	 */
 	if (val & SP5100_WDT_FIRED)
 		wdd->bootstatus = WDIOF_CARDRESET;
+	/* Set watchdog action to reset the system */
 	val &= ~SP5100_WDT_ACTION_RESET;
 	writel(val, SP5100_WDT_CONTROL(tco->tcobase));
 
diff --git a/drivers/watchdog/sp5100_tco.h b/drivers/watchdog/sp5100_tco.h
index ca0721c8d879..008b2094bd13 100644
--- a/drivers/watchdog/sp5100_tco.h
+++ b/drivers/watchdog/sp5100_tco.h
@@ -19,6 +19,7 @@
 #define SP5100_WDT_START_STOP_BIT	BIT(0)
 #define SP5100_WDT_FIRED		BIT(1)
 #define SP5100_WDT_ACTION_RESET		BIT(2)
+#define SP5100_WDT_DISABLED		BIT(3)
 #define SP5100_WDT_TRIGGER_BIT		BIT(7)
 
 #define SP5100_PM_IOPORTS_SIZE		0x02
-- 
2.7.4