cs5536: add smbus support in ramstage

With this patch it is possible to use the smbus in ramstage. The
biggest part of the patch is a simple code split into a general
part (smbus.h) and the concrete users (early_smbus.c and cs5536.c).
After the switch from romstage to ramstage the smb base address
has changed, but that is no problem as the new base address is
stored in bar0 of the ISA bridge. It could also be read via msr,
but via PCI it is simpler. I used the following patch as
reference on how to readout the new base address:
http://lists.laptop.org/pipermail/commits-kernel/2006-November/000178.html

Change-Id: I9f86a1e474368c62f9ed3a95edfb3e63117aa156
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-on: http://review.coreboot.org/1243
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marcj303@gmail.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

0 files changed, 0 insertions, 0 deletions