[PATCH] gpio: Describe interrupt-controller binding
Thierry Reding
thierry.reding at avionic-design.de
Tue Sep 18 18:35:33 EST 2012
In order to use GPIO controllers as interrupt controllers, they need to
be marked with the DT interrupt-controller property. This commit adds
some documentation about this to the general GPIO binding document.
Cc: Linus Walleij <linus.walleij at stericsson.com>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: devicetree-discuss at lists.ozlabs.org
Cc: linux-kernel at vger.kernel.org
Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
---
Documentation/devicetree/bindings/gpio/gpio.txt | 33 +++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index 4e16ba4..8d125b0 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -75,4 +75,37 @@ Example of two SOC GPIO banks defined as gpio-controller nodes:
gpio-controller;
};
+If the GPIO controller supports the generation of interrupts, it should
+also contain an empty "interrupt-controller" property as well as an
+"#interrupt-cells" property. This is required in order for other nodes
+to use the GPIO controller as their interrupt parent.
+If #interrupt-cells is 1, the single cell is used to specify the number
+of the GPIO that is to be used as an interrupt.
+
+If #interrupt-cells is 2, the first cell is used to specify the number
+of the GPIO that is to be used as an interrupt, whereas the second cell
+is used to specify any of the following flags:
+ - bits[3:0] trigger type and level flags
+ 1 = low-to-high edge triggered
+ 2 = high-to-low edge triggered
+ 4 = active high level-sensitive
+ 8 = active low level-sensitive
+
+Example:
+
+ gpioext: gpio-controller at 41 {
+ compatible = "ad,gpio-adnp";
+ reg = <0x41>;
+
+ interrupt-parent = <&gpio>;
+ interrupts = <160 1>;
+
+ gpio-controller;
+ #gpio-cells = <2>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ nr-gpios = <64>;
+ };
--
1.7.12
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