[PATCH] watchdog: Handle multiple wm831x watchdogs being registered

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

Due to the whole single instance based watchdog API we use static data
for the wm831x watchdog which means that if the system tries to register
a second one we end up trying to register the same miscdevice again,
corrupting the miscdevice list. Work around this by checking for duplicate
registrations until we get a watchdog core.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
 drivers/watchdog/wm831x_wdt.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/watchdog/wm831x_wdt.c b/drivers/watchdog/wm831x_wdt.c
index 8c4b2d5..871caea 100644
--- a/drivers/watchdog/wm831x_wdt.c
+++ b/drivers/watchdog/wm831x_wdt.c
@@ -320,6 +320,11 @@ static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
 	struct wm831x_watchdog_pdata *pdata;
 	int reg, ret;
 
+	if (wm831x) {
+		dev_err(&pdev->dev, "wm831x watchdog already registered\n");
+		return -EBUSY;
+	}
+
 	wm831x = dev_get_drvdata(pdev->dev.parent);
 
 	ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
-- 
1.7.5.1