[coreboot-gerrit] Change in coreboot[master]: sb/intel: Introduce SCMI Kconfig options

[Keith Hui (Code Review)]

Keith Hui has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/48921 )

Change subject: sb/intel: Introduce SCMI Kconfig options
......................................................................

sb/intel: Introduce SCMI Kconfig options

Introduce two options for enabling SMBus Control Method Interface [1] support.

1. HAVE_SCMI is to be set by southbridges that implements SCMI in the DSDT.
   That implementation should be conditional on USE_SCMI. See below.
2. USE_SCMI is guarded by HAVE_SCMI and actually provides the option to the
   user in Kconfig. Enabling it adds the SCMI implementation to the DSDT and
   make it usable. Boards that require this support for board function should
   set it in their BOARD_SPECIFIC_OPTIONS, which will lock this option on.

It will be used by CB:41735 but are designed for wider adoption e.g. by CB:44507

[1] http://smbus.org/specs/smbus_cmi10.pdf
[41735] https://review.coreboot.org/c/coreboot/+/41735
[44507] https://review.coreboot.org/c/coreboot/+/44507

Change-Id: Ib1e176b6495fa673fd46cbb8f8fd7c5a41ababde
Signed-off-by: Keith Hui 
---
M src/southbridge/intel/common/Kconfig
1 file changed, 19 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/21/48921/1

diff --git a/src/southbridge/intel/common/Kconfig b/src/southbridge/intel/common/Kconfig
index 3030d25..11ba094 100644
--- a/src/southbridge/intel/common/Kconfig
+++ b/src/southbridge/intel/common/Kconfig
@@ -105,3 +105,22 @@
    hex
    depends on SOUTHBRIDGE_INTEL_COMMON_SMBUS
    default 0x400
+
+config HAVE_SCMI
+	bool
+	help
+	  Selected by southbridges that implements SCMI in their DSDT.
+	  See http://smbus.org/specs/smbus_cmi10.pdf for details.
+
+config USE_SCMI
+	bool "Enable SMBus Control Method Interface (SCMI)"
+	depends on HAVE_SCMI && HAVE_ACPI_TABLES
+	help
+	  Adds extra access methods conforming to the SMBus Control Method Interface (SCMI)
+	  specification to the SMBus ACPI device. This provides alternate SMBus access if
+	  regular means are unavailable due to e.g. resource conflicts.
+
+	  ASUS P3B-F mainboard is known to need this.
+
+	  If you say Y here, you will have to blacklist the native driver and instead use
+	  i2c-scmi driver to access SMBus-connected devices.