soc/intel/lpc_lib: mirror LPC registers to DMI when required

Starting with SPT, LPC registers IOD, IOE, LGIR* and LGMR need to be
mirrored to their corresponding DMI registers. Add the required writes
to DMI registers, where the PCI config registers get written.

This is already done in soc code for IOD, IOE and LGIR* by mirroring
the registers later, during PCH init. Also the code mostly matches
accross the platforms. This common implementation will avoid delayed
mirroring of the registers and also deduplicate the code.

This change also adds a new Kconfig that will be selected by platforms
requiring mirroring of LPC IO/MMIO registers to their corresponding DMI
registers.

For making use of this common code, the redundant soc code needs to be
dropped and the newly introduced Kconfig option has to be selected. This
is done in the follow-up change.

Change-Id: I39f3bf4c486a1bbc112b2b453381de6da4bbac4d
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49592
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/include/intelblocks/lpc_lib.h b/src/soc/intel/common/block/include/intelblocks/lpc_lib.h
index bf5c2f68f6..c5842d5f2c 100644
--- a/src/soc/intel/common/block/include/intelblocks/lpc_lib.h
+++ b/src/soc/intel/common/block/include/intelblocks/lpc_lib.h
@@ -30,6 +30,8 @@
 #define PCR_DMI_LPCLGIR3		0x2738
 #define PCR_DMI_LPCLGIR4		0x273c
 
+#define PCR_DMI_LPCGMR			0x2740
+
 #define PCR_DMI_LPCIOD			0x2770
 #define PCR_DMI_LPCIOE			0x2774