tree 9596c55a4a74e9b139dbc6d01d5d2d609b7267a1
parent 18c11986674ae917aad2465ef88cbb2c4e92b170
author Masahiro Yamada <yamada.masahiro@socionext.com> 1466159069 +0900
committer Masahiro Yamada <yamada.masahiro@socionext.com> 1466374533 +0900

ARM: uniphier: reserve memory for DRAM PHY training on PH1-LD20

The DRAM PHY layer on PH1-LD20 is able to calibrate PHY parameters
periodically.  This compensates for the voltage and temperature
deviation and improves the PHY parameter adjustment.  Instead, it
requires 64 byte scratch memory in each DRAM channel for the dynamic
training.  The memory regions must be reserved in DT before jumping
to the kernel.

The scratch area can be anywhere in each DRAM channel, but the DRAM
init code in SPL currently assigns it at the end of each channel.
So, it makes sense to reserve the regions on run-time by U-Boot
instead of statically embedding it in the DT in Linux.  Anyway,
a boot-loader should know much more about memory initialization
than the kernel.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>