lynxpoint: Route all USB ports to XHCI in finalize step

This commit adds a new Kconfig option for the LynxPoint
southbridge that will have coreboot route all of the USB
ports to the XHCI controller in the finalize step (i.e.
after the bootloader) and disable the EHCI controller(s).

Additionally when doing this the XHCI USB3 ports need
to be put into an expected state on resume in order to make
the kernel state machine happy.

Part of this could also be done in depthcharge but there
are also some resume-time steps required so it makes sense
to keep it all together in coreboot.

This can theoretically save ~100mW at runtime.

Verify that the EHCI controller is not found in Linux and
that booting from USB still works.

Change-Id: I3ddfecc0ab12a4302e6034ea8d13ccd8ea2a655d
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/63802
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/4407
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/southbridge/intel/lynxpoint/Kconfig b/src/southbridge/intel/lynxpoint/Kconfig
index 28ebdb6c2f..5ff00db1e6 100644
--- a/src/southbridge/intel/lynxpoint/Kconfig
+++ b/src/southbridge/intel/lynxpoint/Kconfig
@@ -76,4 +76,11 @@ config ME_MBP_CLEAR_LATE
 	  finalize step.  This can speed up boot time if the ME takes
 	  a long time to indicate this status.
 
+config FINALIZE_USB_ROUTE_XHCI
+	bool "Route all ports to XHCI controller in finalize step"
+	default y
+	help
+	  If you set this option to y, the USB ports will be routed
+	  to the XHCI controller during the finalize SMM callback.
+
 endif