gpio-kbd-matrix

Vendor: Generic or vendor-independent

Note

An implementation of a driver matching this compatible is available in drivers/input/input_gpio_kbd_matrix.c.

Description

GPIO based keyboard matrix input device

Implement an input device for a GPIO based keyboard matrix.

Example configuration:

kbd-matrix {
        compatible = "gpio-kbd-matrix";
        row-gpios = <&gpio0 0 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>,
                    <&gpio0 1 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
        col-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>,
                    <&gpio0 3 GPIO_ACTIVE_LOW>,
                    <&gpio0 4 GPIO_ACTIVE_LOW>;
        no-ghostkey-check;
};

Properties

Node specific properties

Properties not inherited from the base binding file.

Name

Type

Details

row-gpios

phandle-array

 
GPIO for the keyboard matrix rows, up to 8 different GPIOs. All row GPIO
pins must have interrupt support if idle-mode is set to "interrupt"
(default).

This property is required.

col-gpios

phandle-array

 
GPIO for the keyboard matrix columns, supports up to 32 different GPIOs.
When unselected, this pin will be either driven to inactive state or
configured to high impedance (input) depending on the col-drive-inactive
property.

This property is required.

col-drive-inactive

boolean

 
If enabled, unselected column GPIOs will be driven to inactive state.
Default to configure unselected column GPIOs to high impedance.

idle-mode

string

 
Controls the driver behavior on idle, "interrupt" waits for a new key
press using GPIO interrupts on the row lines, "poll"  periodically polls
the row lines with all the columns selected, "scan" just keep scanning
the matrix continuously, requires "poll-timeout-ms" to be set to 0.

Default value: interrupt

Legal values: 'interrupt', 'poll', 'scan'

poll-period-ms

int

 
Defines the poll period in msecs between between matrix scans, set to 0
to never exit poll mode. Defaults to 5ms if unspecified.

Default value: 5

poll-timeout-ms

int

 
How long to wait before going from polling back to idle state. Defaults
to 100ms if unspecified.

Default value: 100

debounce-down-ms

int

 
Debouncing time for a key press event. Defaults to 10ms if unspecified.

Default value: 10

debounce-up-ms

int

 
Debouncing time for a key release event. Defaults to 20ms if unspecified.

Default value: 20

settle-time-us

int

 
Delay between setting column output and reading the row values. Defaults
to 50us if unspecified.

Default value: 50

actual-key-mask

array

 
Keyboard scanning mask. For each keyboard column, specify which keyboard rows actually exist. Can be used to avoid triggering the ghost detection on non existing keys. No masking by default, any combination is valid.

no-ghostkey-check

boolean

 
Ignore the ghost key checking in the driver if the diodes are used
in the matrix hardware.

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

Base properties

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “gpio-kbd-matrix” compatible.

Name

Type

Details

status

string

 
indicates the operational status of a device

Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss'

See Important properties for more information.

compatible

string-array

 
compatible strings

This property is required.

See Important properties for more information.

reg

array

 
register space

See Important properties for more information.

reg-names

string-array

 
name of each register space

interrupts

array

 
interrupts for device

See Important properties for more information.

interrupts-extended

compound

 
extended interrupt specifier for device

interrupt-names

string-array

 
name of each interrupt

interrupt-parent

phandle

 
phandle to interrupt controller node

label

string

 
Human readable string describing the device (used as device_get_binding() argument)

See Important properties for more information.

This property is deprecated.

clocks

phandle-array

 
Clock gate information

clock-names

string-array

 
name of each clock

#address-cells

int

 
number of address cells in reg property

#size-cells

int

 
number of size cells in reg property

dmas

phandle-array

 
DMA channels specifiers

dma-names

string-array

 
Provided names of DMA channel specifiers

io-channels

phandle-array

 
IO channels specifiers

io-channel-names

string-array

 
Provided names of IO channel specifiers

mboxes

phandle-array

 
mailbox / IPM channels specifiers

mbox-names

string-array

 
Provided names of mailbox / IPM channel specifiers

power-domains

phandle-array

 
Power domain specifiers

power-domain-names

string-array

 
Provided names of power domain specifiers

#power-domain-cells

int

 
Number of cells in power-domains property

zephyr,deferred-init

boolean

 
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().

wakeup-source

boolean

 
Property to identify that a device can be used as wake up source.

When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.

Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.

zephyr,pm-device-runtime-auto

boolean

 
Automatically configure the device for runtime power management after the
init function runs.

zephyr,disabling-power-states

phandles

 
List of power states that will disable this device power.