soc: apple: Add support for the PMP co-processor

This is the core part of a power management co-processor present
on certain Apple SoCs. This driver starts the firmware, and
uploads the configuration and calibration data by pretending
to be IOKit.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>

Author: WhatAmISupposedToPutHere

drivers/soc/apple/Kconfig

@@ -75,6 +75,18 @@ config APPLE_SEP
 
 	  Say 'y' here if you have an Apple SoC.
 
+config APPLE_PMP
+	tristate "Apple Power Management Processor"
+	depends on ARCH_APPLE || COMPILE_TEST
+	depends on RUST
+	select RUST_APPLE_RTKIT
+	default y if ARCH_APPLE
+	help
+	  A co-processor present on Apple SoCs, controlling power states of
+	  fabric and other uncore components.
+
+	  Say 'y' here if you have an Apple SoC.
+
 endmenu
 
 endif

drivers/soc/apple/Makefile

@@ -12,3 +12,5 @@ apple-sart-y = sart.o
 obj-$(CONFIG_APPLE_AOP) += aop.o
 
 obj-$(CONFIG_APPLE_SEP) += sep.o
+
+obj-$(CONFIG_APPLE_PMP) += pmp.o