ROHM BD79100 Analog to Digital Converter (ADC)

The ROHM BD79100 ADC is a single-channel, 12-bit ADC which is controlled over SPI.

Linux Driver:

Source Code:

The ROHM Finland SWDC has added support for the BD79100 in the existing Linux driver, in collaboration with the Linux kernel community. Driver is included in the Upstream Linux from v6.18-rc1 onwards.

The Linux kernel can be obtained from:

https://www.kernel.org/

or by cloning Linus Torvald’s official linux development tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux.git

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,bd79100";
            reg = <0>;
            vdd-supply = <&dummyreg>; 
            iovdd-supply = <&dummyreg>;
            spi-cpha;
            spi-cpol;
            spi-max-frequency = <20000000>;
        };
    }