From 82cce4d2b46ccc554b71efa179b5d95756e2ad5e Mon Sep 17 00:00:00 2001
From: Aaron Durbin <adurbin@chromium.org>
Date: Thu, 6 Feb 2014 10:21:24 -0600
Subject: [PATCH] baytrail: lock down registers before handoff

The following registers are locked before OS resume
handoff or payload handoff:

- SMI_LOCK - global SMI enable
- BILD - bios bootblock settings
- CF9 - cf9 reset settings
- BCR - control of SMI generation on BIOS writes

BUG=chrome-os-partner:24624
BRANCH=baytrail
TEST=Built and booted. S3 resume. Checked register settings.

Change-Id: I19758af6f2edaf78130dcf6cd5525cbfcbe6a261
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/185200
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
---
 src/soc/intel/baytrail/baytrail/lpc.h |  4 ++++
 src/soc/intel/baytrail/southcluster.c | 29 +++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/soc/intel/baytrail/baytrail/lpc.h b/src/soc/intel/baytrail/baytrail/lpc.h
index 31de3105e2..2f6256cc41 100644
--- a/src/soc/intel/baytrail/baytrail/lpc.h
+++ b/src/soc/intel/baytrail/baytrail/lpc.h
@@ -47,4 +47,8 @@ enum baytrail_stepping {
 	STEP_C0,
 };
 
+/* Registers behind the RCBA_BASE_ADDRESS bar. */
+#define GCS		0x00
+# define BILD		(1 << 0)
+
 #endif /* _BAYTRAIL_LPC_H_ */
diff --git a/src/soc/intel/baytrail/southcluster.c b/src/soc/intel/baytrail/southcluster.c
index 527ae648bf..046f3bdab8 100644
--- a/src/soc/intel/baytrail/southcluster.c
+++ b/src/soc/intel/baytrail/southcluster.c
@@ -20,6 +20,7 @@
 
 #include <stdint.h>
 #include <arch/io.h>
+#include <bootstate.h>
 #include <cbmem.h>
 #include <console/console.h>
 #include <device/device.h>
@@ -35,6 +36,7 @@
 #include <baytrail/pci_devs.h>
 #include <baytrail/pmc.h>
 #include <baytrail/ramstage.h>
+#include <baytrail/spi.h>
 #include "chip.h"
 
 static inline void
@@ -419,3 +421,30 @@ static const struct pci_driver southcluster __pci_driver = {
 	.vendor		= PCI_VENDOR_ID_INTEL,
 	.device		= LPC_DEVID,
 };
+
+static void finalize_chipset(void *unused)
+{
+	const unsigned long bcr = SPI_BASE_ADDRESS + BCR;
+	const unsigned long gcs = RCBA_BASE_ADDRESS + GCS;
+	const unsigned long gen_pmcon2 = PMC_BASE_ADDRESS + GEN_PMCON2;
+	const unsigned long etr = PMC_BASE_ADDRESS + ETR;
+
+	/* Set the lock enable on the BIOS control register. */
+	write32(bcr, read32(bcr) | BCR_LE);
+
+	/* Set BIOS lock down bit controlling boot block size and swapping. */
+	write32(gcs, read32(gcs) | BILD);
+
+	/* Lock sleep stretching policy and set SMI lock. */
+	write32(gen_pmcon2, read32(gen_pmcon2) | SLPSX_STR_POL_LOCK | SMI_LOCK);
+
+	/*  Set the CF9 lock. */
+	write32(etr, read32(etr) | CF9LOCK);
+}
+
+BOOT_STATE_INIT_ENTRIES(finalize_bscb) = {
+	BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY,
+	                      finalize_chipset, NULL),
+	BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT,
+	                      finalize_chipset, NULL),
+};