rtc: isl1219: add device tree documentation

The devicetree documentation for the ISL1219 device tree
binding is added with a short example. It is not a trivial
device, because it supports two interrupt sources.

Signed-off-by: Denis Osterland <Denis.Osterland@diehl.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/rtc/isil,isl1219.txt b/Documentation/devicetree/bindings/rtc/isil,isl1219.txt
new file mode 100644
index 000000000000..c3efd48e91c2
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/isil,isl1219.txt
@@ -0,0 +1,29 @@
+Intersil ISL1219 I2C RTC/Alarm chip with event in
+
+ISL1219 has additional pins EVIN and #EVDET for tamper detection.
+
+Required properties supported by the device:
+
+ - "compatible": must be "isil,isl1219"
+ - "reg": I2C bus address of the device
+
+Optional properties:
+
+ - "interrupt-names": list which may contains "irq" and "evdet"
+ - "interrupts": list of interrupts for "irq" and "evdet"
+ - "isil,ev-evienb": if present EV.EVIENB bit is set to the specified
+                     value for proper operation.
+
+
+Example isl1219 node with #IRQ pin connected to SoC gpio1 pin12
+ and #EVDET pin connected to SoC gpio2 pin 24:
+
+        isl1219: rtc@68 {
+                compatible = "isil,isl1219";
+                reg = <0x68>;
+                interrupt-names = "irq", "evdet";
+                interrupts-extended = <&gpio1 12 IRQ_TYPE_EDGE_FALLING>,
+                        <&gpio2 24 IRQ_TYPE_EDGE_FALLING>;
+                isil,ev-evienb = <1>;
+        };
+