How do i get kernel source , patch ,etc ... for create I2S drivers Ubuntu 16.04

Shingo Kurimoto
Shingo Kurimoto New Member Posts: 3
i have a up board.

i checked
and setting.

up@upboard:~/wk$ cat /proc/version
Linux version 4.4.0-2-upboard (buildd@lcy01-36) (gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4) ) #12-Ubuntu SMP Thu Dec 1 15:01:52 UTC 2016
up@upboard:~/wk$ uname -r

i want to create driver (I2S)
maybe not support yet.

i try to get kernel source.

add list /etc/apt/source.list
deb ttp:// xenial main
deb-src ttp:// xenial main

>sudo add-apt-repository ppa:ubilinux/up
>sudo apt-get update

>sudo apt-get source linux-upboard

i can get linux-meta-upboard_4.

but this file is not kernel source..

please tell me. URL or How to