Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt

Source file repositories/reference/linux-study-clean/Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt

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System
Linux kernel
Corpus path
Documentation/devicetree/bindings/input/brcm,bcm-keypad.txt
Extension
.txt
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3548 bytes
Lines
108
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

Broadcom Keypad controller is used to interface a SoC with a matrix-type
keypad device. The keypad controller supports multiple row and column lines.
A key can be placed at each intersection of a unique row and a unique column.
The keypad controller can sense a key-press and key-release and report the
event using a interrupt to the cpu.

This binding is based on the matrix-keymap binding with the following
changes:

keypad,num-rows and keypad,num-columns are required.

Required SoC Specific Properties:
- compatible: should be "brcm,bcm-keypad"

- reg: physical base address of the controller and length of memory mapped
  region.

- interrupts: The interrupt number to the cpu.

Board Specific Properties:
- keypad,num-rows: Number of row lines connected to the keypad
  controller.

- keypad,num-columns: Number of column lines connected to the
  keypad controller.

- col-debounce-filter-period: The debounce period for the Column filter.

	KEYPAD_DEBOUNCE_1_ms	=	0
	KEYPAD_DEBOUNCE_2_ms	=	1
	KEYPAD_DEBOUNCE_4_ms	=	2
	KEYPAD_DEBOUNCE_8_ms	=	3
	KEYPAD_DEBOUNCE_16_ms	=	4
	KEYPAD_DEBOUNCE_32_ms	=	5
	KEYPAD_DEBOUNCE_64_ms	=	6
	KEYPAD_DEBOUNCE_128_ms	=	7

- status-debounce-filter-period: The debounce period for the Status filter.

	KEYPAD_DEBOUNCE_1_ms	=	0
	KEYPAD_DEBOUNCE_2_ms	=	1
	KEYPAD_DEBOUNCE_4_ms	=	2
	KEYPAD_DEBOUNCE_8_ms	=	3
	KEYPAD_DEBOUNCE_16_ms	=	4
	KEYPAD_DEBOUNCE_32_ms	=	5
	KEYPAD_DEBOUNCE_64_ms	=	6
	KEYPAD_DEBOUNCE_128_ms	=	7

- row-output-enabled: An optional property indicating whether the row or
  column is being used as output. If specified the row is being used
  as the output. Else defaults to column.

- pull-up-enabled: An optional property indicating the Keypad scan mode.
  If specified implies the keypad scan pull-up has been enabled.

- autorepeat: Boolean, Enable auto repeat feature of Linux input
	  subsystem (optional).

- linux,keymap: The keymap for keys as described in the binding document
  devicetree/bindings/input/matrix-keymap.txt.

Example:
#include "dt-bindings/input/input.h"

/ {
	keypad: keypad@180ac000 {
		/* Required SoC specific properties */
		compatible = "brcm,bcm-keypad";

		/* Required Board specific properties */

Annotation

Implementation Notes