tree c6734207c165bd38a469537247052df67c5c73fa
parent f3ff0b2b3633e635c9b7d017a77536e45ab5f0a6
author Lukasz Majewski <lukma@denx.de> 1544025842 +0100
committer Stefano Babic <sbabic@denx.de> 1550229410 +0100

ddr: vybrid: Provide code to perform on-boot calibration

This patch provides the code to calibrate the DDR's
DQS to DQ signals (RDLVL).

It is based on:
VFxxx Controller Reference Manual, Rev. 0, 10/2016, page 1600
10.1.6.16.4.1 "Software Read Leveling in MC Evaluation Mode"

and NXP's community thread:
"Vybrid: About DDR leveling feature on DDRMC."
https://community.nxp.com/thread/395323

Signed-off-by: Lukasz Majewski <lukma@denx.de>