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authorHans de Goede <hdegoede@redhat.com>2014-12-18 09:24:50 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2014-12-21 18:59:21 -0800
commitaf6a5af8e8cc1566fc06636de02347825808650e (patch)
treed40074d31035c565772a92167b390b4850dab6bc /Documentation/devicetree
parentd64cb71bede87dbca60d586a7bb4cef87fbe2731 (diff)
Input: add new sun4i-lradc-keys driver
Allwinnner sunxi SoCs have a low resolution adc (called lradc) which is specifically designed to have various (tablet) keys (ie home, back, search, etc). attached to it using a resistor network. This adds a driver for this. There are 2 channels, currently this driver only supports chan0 since there are no boards known to use chan1. This has been tested on an olimex a10s-olinuxino-micro, a13-olinuxino, and a20-olinuxino-micro. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt62
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt b/Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt
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+Allwinner sun4i low res adc attached tablet keys
+------------------------------------------------
+
+Required properties:
+ - compatible: "allwinner,sun4i-a10-lradc-keys"
+ - reg: mmio address range of the chip
+ - interrupts: interrupt to which the chip is connected
+ - vref-supply: powersupply for the lradc reference voltage
+
+Each key is represented as a sub-node of "allwinner,sun4i-a10-lradc-keys":
+
+Required subnode-properties:
+ - label: Descriptive name of the key.
+ - linux,code: Keycode to emit.
+ - channel: Channel this key is attached to, mut be 0 or 1.
+ - voltage: Voltage in µV at lradc input when this key is pressed.
+
+Example:
+
+#include <dt-bindings/input/input.h>
+
+ lradc: lradc@01c22800 {
+ compatible = "allwinner,sun4i-a10-lradc-keys";
+ reg = <0x01c22800 0x100>;
+ interrupts = <31>;
+ vref-supply = <&reg_vcc3v0>;
+
+ button@191 {
+ label = "Volume Up";
+ linux,code = <KEY_VOLUMEUP>;
+ channel = <0>;
+ voltage = <191274>;
+ };
+
+ button@392 {
+ label = "Volume Down";
+ linux,code = <KEY_VOLUMEDOWN>;
+ channel = <0>;
+ voltage = <392644>;
+ };
+
+ button@601 {
+ label = "Menu";
+ linux,code = <KEY_MENU>;
+ channel = <0>;
+ voltage = <601151>;
+ };
+
+ button@795 {
+ label = "Enter";
+ linux,code = <KEY_ENTER>;
+ channel = <0>;
+ voltage = <795090>;
+ };
+
+ button@987 {
+ label = "Home";
+ linux,code = <KEY_HOMEPAGE>;
+ channel = <0>;
+ voltage = <987387>;
+ };
+ };