* H1 Secure Microcontroller with Cr50 Firmware on SPI Bus. H1 Secure Microcontroller running Cr50 firmware provides several functions, including TPM-like functionality. It communicates over SPI using the FIFO protocol described in the PTP Spec, section 6. Required properties: - compatible: Should be "google,cr50". - spi-max-frequency: Maximum SPI frequency. Example: &spi0 { tpm@0 { compatible = "google,cr50"; reg = <0>; spi-max-frequency = <800000>; }; };