cr50: Support closed source customer diagnostic mode

Drives OEM specific GPIOS to enable diagnostic mode on a closed source
EC.

BUG=b:122312536
BRANCH=cr50
TEST=make buildall. Verified GPIO states with scope at boot and after
sending TPM disable command from the AP.  Diagnostic mode is cleared on
reboot.
Change-Id: Id7c9d7e5cc63e5e6f56451ceaca04eeddb254f7d
Signed-off-by: Keith Short <keithshort@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1394692
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

3 files changed, 25 insertions, 3 deletions

diff --git a/board/cr50/closed_source_set1.c b/board/cr50/closed_source_set1.c
index 8c0a7f2829..058573fb46 100644
--- a/board/cr50/closed_source_set1.c
+++ b/board/cr50/closed_source_set1.c
@@ -54,15 +54,12 @@ void closed_source_set1_configure_gpios(void)
 	 * here.
 	 */
 
-	/* Enable falling edge interrupt on I2C_SDA_SCL/EXIT_FACTORY_MODE */
-
 	/*
 	 * TODO (keithshort): closed source EC documentation defines
 	 * EXIT_FACTORY_MODE as an output from the EC that is driven low
 	 * to indicate that factory mode must be terminated.  However, the
 	 * EC firmware has not yet (and may never) add this capability.
 	 */
-//	gpio_set_flags(GPIO_EXIT_FACTORY_MODE, GPIO_INPUT | GPIO_INT_F_FALLING);
 
 	closed_source_set1_update_factory_mode();
 }
@@ -120,6 +117,20 @@ void closed_source_set1_update_factory_mode(void)
 		closed_source_set1_update_ec_trust_level(EC_TL_COREBOOT);
 }
 
+void close_source_set1_disable_tpm(void)
+{
+	/*
+	 * Once the TPM mode is disabled from the AP, set the EC trust level
+	 * to permit running diagnostics.  Diagnostic mode may be entered from
+	 * any of the EC trust level states, so no additional checks are needed.
+	 *
+	 * This state is only cleared by a reboot of the Cr50 and then the
+	 * trust level reverts back to either EC_TL_FACTORY_MODE or
+	 * EC_TL_COREBOOT.
+	 */
+	closed_source_set1_update_ec_trust_level(EC_TL_DIAGNOSTIC_MODE);
+}
+
 
 #ifdef CR50_DEV
 /* Debug command to manually set the EC trust level */
diff --git a/board/cr50/closed_source_set1.h b/board/cr50/closed_source_set1.h
index 44f7e39be0..0970726f45 100644
--- a/board/cr50/closed_source_set1.h
+++ b/board/cr50/closed_source_set1.h
@@ -21,5 +21,11 @@ void closed_source_set1_configure_gpios(void);
  */
 void closed_source_set1_update_factory_mode(void);
 
+/**
+ * In response to a TPM_MODE disable, drive the GPIOs specific to
+ * BOARD_CLOSED_SOURCE_SET1 to match the diagnostic state setting.
+ */
+void close_source_set1_disable_tpm(void);
+
 
 #endif   /* ! __EC_BOARD_CR50_CLOSED_SOURCE_SET1_H */
diff --git a/board/cr50/tpm2/tpm_mode.c b/board/cr50/tpm2/tpm_mode.c
index 404000d60a..9978f7f724 100644
--- a/board/cr50/tpm2/tpm_mode.c
+++ b/board/cr50/tpm2/tpm_mode.c
@@ -6,6 +6,8 @@
 
 #include "config.h"
 #include "Global.h"
+#include "board.h"
+#include "closed_source_set1.h"
 #include "console.h"
 #include "dcrypto.h"
 #include "extension.h"
@@ -24,6 +26,9 @@ static void disable_tpm(void)
 	tpm_stop();
 	DCRYPTO_ladder_revoke();
 	nvmem_clear_cache();
+
+	if (board_uses_closed_source_set1())
+		close_source_set1_disable_tpm();
 }
 DECLARE_DEFERRED(disable_tpm);