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authorAlexander Shiyan <shc_work@mail.ru>2013-11-30 11:54:32 +0400
committerWim Van Sebroeck <wim@iguana.be>2014-01-28 21:21:02 +0100
commit25134eafb05eef6dd4b6caee3a711b63ee0c3737 (patch)
tree17cd804d9904ad9c561b7efcbd9341c8578b7094 /Documentation/devicetree
parent8832b20093434514fda5e8a0c885270eda4fbf40 (diff)
watchdog: GPIO-controlled watchdog
This patch adds a watchdog driver for devices controlled through GPIO, (Analog Devices ADM706, Maxim MAX823, National NE555 etc). Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/watchdog/gpio-wdt.txt23
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt
new file mode 100644
index 000000000000..37afec194949
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt
@@ -0,0 +1,23 @@
+* GPIO-controlled Watchdog
+
+Required Properties:
+- compatible: Should contain "linux,wdt-gpio".
+- gpios: From common gpio binding; gpio connection to WDT reset pin.
+- hw_algo: The algorithm used by the driver. Should be one of the
+ following values:
+ - toggle: Either a high-to-low or a low-to-high transition clears
+ the WDT counter. The watchdog timer is disabled when GPIO is
+ left floating or connected to a three-state buffer.
+ - level: Low or high level starts counting WDT timeout,
+ the opposite level disables the WDT. Active level is determined
+ by the GPIO flags.
+- hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds).
+
+Example:
+ watchdog: watchdog {
+ /* ADM706 */
+ compatible = "linux,wdt-gpio";
+ gpios = <&gpio3 9 GPIO_ACTIVE_LOW>;
+ hw_algo = "toggle";
+ hw_margin_ms = <1600>;
+ };

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