nb/via/cx700: Implement raminit

This brings the old raminit implementation for CX700 back. It was
removed in commit e99f0390b9b8 (Remove VIA CX700 northbridge sup-
port). The code is mostly unchanged, three minor issues are fixed:

* A shift (>>= 2) was missing when reading tRRD from SPD byte 28.
  The fixed value matches  what the vendor BIOS of a VIA EPIA-EX
  board programs. The code also suggests that we are looking for
  a small value (<= 19 for DDR2-533).

* We allow the board port to specify which clock outputs should
  be enabled now.  This is necessary for the VIA EPIA-EX, which
  needs the ALL_MCLKO setting  (instead of the previously hard-
  coded MCLKO2.

* When programming the DQS output delays, we considered the 1~2
  rank values only for single-rank configurations. Changing the
  `< 2` to `<= 2`  brings us closer to the vendor values on the
  VIA EPIA-EX.

Otherwise a lot of cosmetics changed. Partly because the original
code was to be #included into another C file, but also to satisfy
checkpatch. Also, all the #if'd code was removed (32-bit width
option, ECC, etc.).

Change-Id: Ibc36b4f314cdf47f18c8be0fcb98218c50938e94
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82770
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mainboard/via/epia-ex/devicetree.cb b/src/mainboard/via/epia-ex/devicetree.cb
index 3f76279175..732d02490c 100644
--- a/src/mainboard/via/epia-ex/devicetree.cb
+++ b/src/mainboard/via/epia-ex/devicetree.cb
@@ -1,6 +1,14 @@
 chip northbridge/via/cx700
 
 	device domain 0 on
+
+		device ref dram_ctrl on
+			register "dram_cfg" = "{
+				.spd_addr = { 0x50, },
+				.mem_clocks = ALL_MCLKO,
+			 }"
+		end
+
 	end
 
 end