forked from Minki/linux
af6a5af8e8
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>
63 lines
1.4 KiB
Plaintext
63 lines
1.4 KiB
Plaintext
Allwinner sun4i low res adc attached tablet keys
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Required properties:
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- compatible: "allwinner,sun4i-a10-lradc-keys"
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- reg: mmio address range of the chip
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- interrupts: interrupt to which the chip is connected
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- vref-supply: powersupply for the lradc reference voltage
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Each key is represented as a sub-node of "allwinner,sun4i-a10-lradc-keys":
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Required subnode-properties:
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- label: Descriptive name of the key.
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- linux,code: Keycode to emit.
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- channel: Channel this key is attached to, mut be 0 or 1.
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- voltage: Voltage in µV at lradc input when this key is pressed.
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Example:
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#include <dt-bindings/input/input.h>
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lradc: lradc@01c22800 {
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compatible = "allwinner,sun4i-a10-lradc-keys";
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reg = <0x01c22800 0x100>;
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interrupts = <31>;
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vref-supply = <®_vcc3v0>;
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button@191 {
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label = "Volume Up";
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linux,code = <KEY_VOLUMEUP>;
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channel = <0>;
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voltage = <191274>;
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};
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button@392 {
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label = "Volume Down";
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linux,code = <KEY_VOLUMEDOWN>;
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channel = <0>;
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voltage = <392644>;
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};
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button@601 {
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label = "Menu";
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linux,code = <KEY_MENU>;
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channel = <0>;
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voltage = <601151>;
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};
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button@795 {
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label = "Enter";
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linux,code = <KEY_ENTER>;
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channel = <0>;
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voltage = <795090>;
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};
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button@987 {
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label = "Home";
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linux,code = <KEY_HOMEPAGE>;
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channel = <0>;
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voltage = <987387>;
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};
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};
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