Cpu Idle Driver for the AT91 processors

modulename: cpuidle-at91.ko

configname: CONFIG_ARM_AT91_CPUIDLE

Linux Kernel Configuration
└─>Power management and ACPI options
└─>CPU Idle
└─>ARM CPU Idle Drivers
└─>Cpu Idle Driver for the AT91 processors
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Select this to enable cpuidle for AT91 processors.

source code:
drivers/cpuidle/cpuidle-at91.c
depends
CONFIG_CPU_IDLE
NOT CONFIG_ARM64
CONFIG_ARCH_AT91 or CONFIG_COMPILE_TEST
CONFIG_ARM or CONFIG_ARM64