nxp,dmic

Vendor: NXP Semiconductors

Note

An implementation of a driver matching this compatible is available in drivers/audio/dmic_mcux.c.

Description

NXP DMIC

Properties

Top level properties

These property descriptions apply to “nxp,dmic” nodes themselves. This page also describes child node properties in the following sections.

Properties not inherited from the base binding file.

Name

Type

Details

pinctrl-0

phandles

Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.

This property is required.

use2fs

boolean

Use 2FS output, and bypass final half band decimator. This will reduce
the required PDM bit clock frequency by a factor of two, and can reduce
power consumption.

pinctrl-1

phandles

Pin configuration/s for the second state. See pinctrl-0.

pinctrl-2

phandles

Pin configuration/s for the third state. See pinctrl-0.

pinctrl-3

phandles

Pin configuration/s for the fourth state. See pinctrl-0.

pinctrl-4

phandles

Pin configuration/s for the fifth state. See pinctrl-0.

pinctrl-names

string-array

Names for the provided states. The number of names needs to match the
number of states.

Child node properties

Name

Type

Details

reg

array

Information used to address the device. The value is specific to
the device (i.e. is different depending on the compatible
property).

The "reg" property is typically a sequence of (address, length) pairs.
Each pair is called a "register block". Values are
conventionally written in hex.

For details, see "2.3.6 reg" in Devicetree Specification v0.4.

This property is required.

See Important properties for more information.

dmas

phandle-array

DMA channel specifiers relevant to the device.

This property is required.

gainshift

int

Decimator gain shift. Sets the number of bits to shift decimated PCM
data by, as a positive or negative number. Range of [-15,15]. Default
is reset value of register

compensation-2fs

string

2FS compensation filter. See SOC reference manual for filter response
of each value. Default value is reset value of register, and
recommended filter setting.

Default value: zero

Legal values: 'zero', '-0.16', '-0.15', '-0.13'

compensation-4fs

string

4FS compensation filter. See SOC reference manual for filter response
of each value. Default value is reset value of register, and
recommended filter setting.

Default value: zero

Legal values: 'zero', '-0.16', '-0.15', '-0.13'

dc-cutoff

string

DC cutoff filter setting. Default is reset value of register. Note that
each cutoff frequency is based on a sample frequency of 16KHz, so
actual cutoff values will scale up or down based on your sampling
frequency

Default value: flat

Legal values: 'flat', '155hz', '78hz', '39hz'

dc-gain

int

DC gain fine adjustment. Number of bits to downshift the final
conversion result. Max value of 15. Default is reset value of
register