Can't set CONFIG_BOARD_ENABLE_DCDC=n on custom board

[alex101]

Hi there,

I have a small custom board with the nRF52810 that uses the LDO instead of the DC-DC, it also doesn't have the 32KHz LF crystal.

Was able to add this to the defconfig file / prj.conf which compiles fine:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

But in trying to add CONFIG_BOARD_ENABLE_DCDC=n and re-compiling results in an error:
warning: attempt to assign the value 'n' to the undefined symbol BOARD_ENABLE_DCDC

Does anyone know how to solve this? The other threads I've seen show it works for others but that was a year ago or more.

Thank you!

[X4ce]

Hi,

Try adding a filename "Kconfig" in your custom board folder with following contents:

config BOARD_ENABLE_DCDC
    bool "DCDC mode"
    select SOC_DCDC_NRF52X
    default n
    depends on BOARD_YOUR_BOARD_NAME

Regards

[alex101]

Thank you for the quick reply! I added it and it seems to compile but I don't know if it's been set properly?

I say that because if I click on "SOC_DCDC_NRF52X" and go to it's definition it says:

config SOC_DCDC_NRF52X

    bool

    select DEPRECATED

    help

      This option is deprecated, use devicetree instead. Example

      configuration:

      &reg/reg1 {

        regulator-initial-mode = <NRF5X_REG_MODE_DCDC>;

      };

      Enable nRF52 series System on Chip DC/DC converter.

And then if I try to add the &reg/reg1 to the device tree dts file, it says this register doesn't exist.

[X4ce]

Which NCS you're using? This link gives:

Internal regulators present in nRF52/53 series can now be configured using devicetree. The Kconfig options CONFIG_SOC_DCDC_NRF52X, CONFIG_SOC_DCDC_NRF52X_HV, CONFIG_SOC_DCDC_NRF53X_APP, CONFIG_SOC_DCDC_NRF53X_NET and CONFIG_SOC_DCDC_NRF53X_HV selected by board-level Kconfig options have been deprecated.

Example for nRF52 series:

/* configure REG/REG1 in DC/DC mode */
&reg/reg1 {
    regulator-initial-mode = <NRF5X_REG_MODE_DCDC>;
};

/* enable REG0 (HV mode) */
&reg0 {
    status = "okay";
};

Look for reg or reg1 nodes in dts of your specific SoC and use that node.

Regards