summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/input/adc-keys.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/input/adc-keys.txt')
-rw-r--r--Documentation/devicetree/bindings/input/adc-keys.txt22
1 files changed, 20 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/input/adc-keys.txt b/Documentation/devicetree/bindings/input/adc-keys.txt
index e551814629b4..6c8be6a9ace2 100644
--- a/Documentation/devicetree/bindings/input/adc-keys.txt
+++ b/Documentation/devicetree/bindings/input/adc-keys.txt
@@ -5,7 +5,8 @@ Required properties:
- compatible: "adc-keys"
- io-channels: Phandle to an ADC channel
- io-channel-names = "buttons";
- - keyup-threshold-microvolt: Voltage at which all the keys are considered up.
+ - keyup-threshold-microvolt: Voltage above or equal to which all the keys are
+ considered up.
Optional properties:
- poll-interval: Poll interval time in milliseconds
@@ -17,7 +18,12 @@ Each button (key) is represented as a sub-node of "adc-keys":
Required subnode-properties:
- label: Descriptive name of the key.
- linux,code: Keycode to emit.
- - press-threshold-microvolt: Voltage ADC input when this key is pressed.
+ - press-threshold-microvolt: voltage above or equal to which this key is
+ considered pressed.
+
+No two values of press-threshold-microvolt may be the same.
+All values of press-threshold-microvolt must be less than
+keyup-threshold-microvolt.
Example:
@@ -47,3 +53,15 @@ Example:
press-threshold-microvolt = <500000>;
};
};
+
++--------------------------------+------------------------+
+| 2.000.000 <= value | no key pressed |
++--------------------------------+------------------------+
+| 1.500.000 <= value < 2.000.000 | KEY_VOLUMEUP pressed |
++--------------------------------+------------------------+
+| 1.000.000 <= value < 1.500.000 | KEY_VOLUMEDOWN pressed |
++--------------------------------+------------------------+
+| 500.000 <= value < 1.000.000 | KEY_ENTER pressed |
++--------------------------------+------------------------+
+| value < 500.000 | no key pressed |
++--------------------------------+------------------------+