In the nvmem.yml there is
properties: $nodename: pattern: "^(eeprom|efuse|nvram)(@.*|-[0-9a-f])*$" I have a hard time finding the pattern in the source code itself. Where can I find that the nvmem device tree nodename must be 'eeprom' or 'efuse' or 'nvram'.
Device tree node names are communicated to the kernel from the boot firmware, so these are not defined inside the kernel source.
The pattern containing the @ sign is typical for OpenFirmware. Unless your machine boots from OF, it is unlikely that you have any device tree nodes that match here.
The device-tree code still exists on ACPI based systems, as it allows attaching properties to ACPI device nodes, this is used mostly in embedded systems though (e.g. I have an embedded PC here that uses such a property to disable OTG mode and superspeed in the USB device controller).
