roc-rk3328-cc: DDR4 initialisation data

[kvic-z]

I found mainline kernel lacks support for DDR DVFS, but found that Rockchip has provided generic SDRAM initialisation in u-boot. It'll be great if Rockchip or @FireflyTeam can provide one set of SDRAM initialisation data for DDR4 used in roc-rk3328-cc similar to this one.

I have roc-rk3328-cc. It's no fun to run the mainline kernel as the memory performance is very poor when compared to 4.4.x kernel. Would appreciate if you could provide the timing data or suggest another way to restore the memory performance in mainline kernel.

cheers