Wake up using IR remote controller and HDMI CEC

The current ODROID-C2 U-Boot supports Wake-Up functionality after Power Off.
You can do Power-on ODROID-C2 using the power key of HK's Remote Controller and CEC source signal.
This functionality makes just 30mW power increase compared with the old U-Boot.

The ODROID user, Kwiboo implemented IR and CEC wake-up sequences for LibreELEC.
Thank you, Kwiboo!

http://forum.odroid.com/viewtopic.php?f=139&t=23073#p155601
https://github.com/hardkernel/u-boot/issues/26

The available IR remote key is power key of HK's IR remote controller.

Manufacturer Code : 0x4DB2
IR code of Power Button : 0xDC
Key Code : 0x23dc4db2

After power off using shutdown -P or poweroff, pushing Power Button will make ODROID-C2 wake-up and go booting process.

# shutdown -P
...

[   47.067156] reboot: Power down
INFO:    PSCI Affinity Map:
INFO:      AffInst: Level 0, MPID 0x0, State ON
INFO:      AffInst: Level 0, MPID 0x1, State ON
INFO:      AffInst: Level 0, MPID 0x2, State ON
INFO:      AffInst: Level 0, MPID 0x3, State ON
ERprocess cCEC cfg:0x2f
set vddee to 0x0352mv
->> Enter Power Off
...

->> Press Power Button

GXBB:BL1:08dafd:0a8993;FEAT:EDFC318C;POC:3;RCY:0;EMMC:0;READ:0;CHK:0;
TE: 91385
no sdio debug board detected 

BL2 Built : 11:44:26, Nov 25 2015. 
Board ID = 8
set vcck to 1100 mv
set vddee to 1050 mv
CPU clk: 1536MHz
DDR channel setting: DDR0 Rank0+1 same
DDR0: 2048MB(auto) @ 912MHz(2T)-13
Run bl30...
Wait bl30...Done
Sending bl301.....OK. 
Run bl301...
chipidLoad bl33 from eMMC, src: 0x00034200, des: 0x01000000, size: 0x0006a6f0

secure task start!
high task start!
low task start!
NOTICE:  BL3-1: v1.0(debug):4d2e34d
NOTICE:  BL3-1: Built : 17:08:35, Oct 29 2015
INFO:    BL3-1: Initializing runtime services
INFO:    BL3-1: Preparing for EL3 exit to normal world
INFO:    BL3-1: Next image address = 0x1000000
INFO:    BL3-1: Next image spsr = 0x3c9

U-Boot 2015.01-00180-g1471870-dirty (Nov 08 2016 - 17:05:58)

If your monitor supports CEC functionalities, after power off, you can find HDMI-CEC ODROID-C2 component among the external inputs on your monitor as following.

To make the connection with ODROID-C2, select the HDMI-CEC ODROID-C2 source. Then, it makes ODROID-C2 will process the normal booting sequence.

The below diagram shows a wake-up sequence.

The relevant commits have been merged middle of August, 2016 and you can find the history on HK u-boot github.
https://github.com/hardkernel/u-boot/commits/odroidc2-v2015.01

But be warned, we've seperated bl301 firmware source code from u-boot repository because of the issue of build failure on other platforms except X86-64 and support issue of build root.
So, if you want to adjust the routine or change the key code by yourself, please refer to the following wiki page.

http://odroid.com/dokuwiki/doku.php?id=en:c2_building_u-boot#how_to_build_u-boot_with_bl301_firmware

ODROID-C2 consumes only 0.3Watt approximately in the power-off state even the IR receiver and CEC blocks are alive.