Hi3660 Mailbox

modulename: hi3660-mailbox.ko

configname: CONFIG_HI3660_MBOX

Linux Kernel Configuration
└─>Device Drivers
└─>Mailbox Hardware Support
└─>Device Tree and Open Firmware support
└─>Hi3660 Mailbox
In linux kernel since version 4.2 (release Date: 2015-08-30)  
An implementation of the hi3660 mailbox. It is used to send message
between application processors and other processors/MCU/DSP. Select
Y here if you want to use Hi3660 mailbox controller.

source code:
depends
CONFIG_MAILBOX
CONFIG_OF
CONFIG_ARCH_HISI or CONFIG_COMPILE_TEST