ROHM BD79101 Analod to Digital Converter (ADC)

The ROHM BD79101 is a 2-channel, 12-bit ADC which is controlled over SPI.

Resources

Linux Driver:

Source code:

Being upstreamed. See Patches.

Upstream driver is currently expected to land in Linux v6.18

The driver supports reading the ADC channels via the Linux IIO subsystem. SPI MODE 3 (CPOL=1, CPHA=1) should be used.

Linux subsystem:

IIO (Industrial input/output)

Devicetree example:

    spi {
        adc: adc@0 {
            compatible = "rohm,bd79101";
            reg = <0>;
            vdd-supply = <&dummyreg>; 
            iovdd-supply = <&dummyreg>;
            spi-cpha;
            spi-cpol;
            spi-max-frequency = <20000000>;
        };
    }

Known issues

We strongly recommend using the latest upstream version of the driver as plenty of fixes are done to the drivers by the Linux kernel community and there is no database for all known issues. Issues spotted by us during development (like adding support for new hardware or improving feature coverage) may have been reported to the issue tracker.