How To: Make a 4K mobile mon

XPS (2015) , Mac 4K suport list .
MacBook Air 2013 / 2014 support DP 1.1 only, Max Resolution 2560 × 1600 × 30 bpp @ 60 Hz

[DP cable]-> [DP -> EDP (with back light driver) ] -> [4K display panel w/o back light driver]
LQ156D1JX01 have back light driver IC

Megapixy: a 13″ Retina-class screen on a boom arm.
A New High-Resolution Panel – Sharp LQ156D1JX01, Part 1
Page 13 Pin-map of the eDP-to-DisplayPort Cable
A New High-Resolution Panel – Sharp LQ156D1JX01, Part 1”
Best Panels Wiki

Sharp IGZO 4K display panel:
LQ156D1JX01
LQ156D1JW04
LQ156D1JW02

LG 4K:
LP156UD1-SPA2

SAMSUNG:
LTN156FL02-L01

Sharp IGZO 3200*1800 display panel:
LQ140Z1JW01
LQ140Z1JW02
LQ140Z1JW03