For an I2C device, ensure the I2C controller driver is bound:
Compile ( iasl ssdt.asl ) and load via cat ssdt.aml > /sys/kernel/config/acpi/table/ssdt1 . acpi prp0001 0
Thus, acpi prp0001 0 is not going away; it remains a vital “back door” for flexible device description. The string acpi prp0001 0 unlocks a fascinating corner of the Linux kernel’s driver model. It tells a story of hardware abstraction bridging two worlds: the rigid, BIOS-centric ACPI and the flexible, open-source-friendly Device Tree. For an I2C device, ensure the I2C controller