tree 1a7a2bc68d1cda77bb2017cb5716d90a7fdb6c8f
parent 757e0c1d40c2030339fba6c253e77f9345d70b53
author Krystian Hebel <krystian.hebel@3mdeb.com> 1616681127 +0100
committer Felix Held <felix-coreboot@felixheld.de> 1692628988 +0000

device/dram: add DDR4 RCD I2C access functions

Registering Clock Driver (RCD) is responsible for driving address and
control nets on RDIMM and LRDIMM applications. Its operation is
configurable by a set of Register Control Words (RCWs). There are two
ways of accessing RCWs: in-band on the memory channel as MRS commands
("MR7") or through I2C.

Access through I2C is generic, while MRS commands are passed to memory
controller registers in an implementation-specific way.

See JESD82-31 JEDEC standard for full details.

Change-Id: Ie4e6cfaeae16aba1853b33d527eddebadfbd3887
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67060
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>