st,stm32-vref

Description

STM32 VREF+.

The st,stm32-vref sensor driver can report VREF+ via the sensor API.
The STM32 ADC driver may also consume these nodes (channel, factory cal)
when CONFIG_ADC_STM32_VREFINT_CALIBRATE is enabled, to seed
adc_ref_internal(). io-channels names the ADC instance that can convert
VREFINT; several nodes may exist on SoCs where more than one ADC has
that mux. The sensor remains independently usable.

Properties

Properties not inherited from the base binding file.

Name

Type

Details

nvmem-cells

phandle-array

One entry corresponding to the VREFINT_CAL calibration parameter
(factory-measured calibration bandgap voltage) must be provided.

This property is required.

vrefint-cal-mv

int

VDDA/VREF+ voltage in millivolts applied during manufacturing to determine
the internal bandgap voltage reference VREFINT.

This property is required.

vrefint-cal-resolution

int

ADC resolution used for measuring calibration data

This is usually equal to the ADC's native resolution.

Most series have a 12-bit ADC, but 14-bit and 16-bit
also exists on e.g., STM32U5 and STM32H7 series.

Default value: 12

Legal values: 12, 14, 16

nvmem-cell-names

string-array

Names for each nvmem-cells specified.

friendly-name

string

Human readable string describing the sensor. It can be used to
distinguish multiple instances of the same model (e.g., lid accelerometer
vs. base accelerometer in a laptop) to a host operating system.

This property is defined in the Generic Sensor Property Usages of the HID
Usage Tables specification
(https://usb.org/sites/default/files/hut1_3_0.pdf, section 22.5).