drivers/firmware/imx/Kconfig v5.13-rc1

IMX_DSP

IMX DSP Protocol driver

This enables DSP IPC protocol between host AP (Linux)
and the firmware running on DSP.
DSP exists on some i.MX8 processors (e.g i.MX8QM, i.MX8QXP).

It acts like a doorbell. Client might use shared memory to
exchange information with DSP side.

IMX_SCU

IMX SCU Protocol driver

The System Controller Firmware (SCFW) is a low-level system function
which runs on a dedicated Cortex-M core to provide power, clock, and
resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
(QM, QP), and i.MX8QX (QXP, DX).

This driver manages the IPC interface between host CPU and the
SCU firmware running on M4.

IMX_SCU_PD

IMX SCU Power Domain driver

The System Controller Firmware (SCFW) based power domain driver.