gsctool: refactor PP polling into a function

Both CCD and SPI_HASH commands need to enforce physical presence. This
patch separates PP polling into a function which can be used by both
commands.

BRANCH=none
BUG=b:73668125
TEST=verified that running 'gsctool -a -o' on a Robo device still
     allows to unlock CCD with PP enforced.

Change-Id: I49abb0e56ad37664eaad7cc34de44e1ac06e2d1b
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/930567
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 61 insertions, 42 deletions

diff --git a/extra/usb_updater/gsctool.c b/extra/usb_updater/gsctool.c
index 6985501127..399c8fdba0 100644
--- a/extra/usb_updater/gsctool.c
+++ b/extra/usb_updater/gsctool.c
@@ -1619,57 +1619,29 @@ static void process_password(struct transfer_descriptor *td)
 	exit(update_error);
 }
 
-static void process_ccd_state(struct transfer_descriptor *td, int ccd_unlock,
-			      int ccd_open, int ccd_lock)
+/*
+ * This function can be used to retrieve the current PP status from Cr50 and
+ * prompt the user when a PP press is required.
+ *
+ * Physical presence can be required by different gsctool options, for which
+ * Cr50 behavior also differs. The 'command' and 'poll_type' parameters are
+ * used by Cr50 to tell what the host is polling for.
+ */
+static void poll_for_pp(struct transfer_descriptor *td,
+			uint16_t command,
+			uint8_t poll_type)
 {
-	uint8_t payload;
 	uint8_t response;
 	uint8_t prev_response;
 	size_t response_size;
 	int rv;
 
-	if (ccd_unlock)
-		payload = CCDV_UNLOCK;
-	else if (ccd_open)
-		payload = CCDV_OPEN;
-	else
-		payload = CCDV_LOCK;
-
-	response_size = sizeof(response);
-	rv = send_vendor_command(td, VENDOR_CC_CCD,
-				 &payload, sizeof(payload),
-				 &response, &response_size);
-
-	/*
-	 * If password is required - try sending the same subcommand
-	 * accompanied by user password.
-	 */
-	if (rv == VENDOR_RC_PASSWORD_REQUIRED)
-		rv = common_process_password(td, payload);
-
-	if (rv == VENDOR_RC_SUCCESS)
-		return;
-
-	if (rv != VENDOR_RC_IN_PROGRESS) {
-		fprintf(stderr, "Error: rv %d, response %d\n",
-			rv, response_size ? response : 0);
-		exit(update_error);
-	}
-
-	/*
-	 * Physical presence process started, poll for the state the user
-	 * asked for. Only two subcommands would return 'IN_PROGRESS'.
-	 */
-	if (ccd_unlock)
-		payload = CCDV_PP_POLL_UNLOCK;
-	else
-		payload = CCDV_PP_POLL_OPEN;
-
 	prev_response = ~0; /* Guaranteed invalid value. */
+
 	while (1) {
 		response_size = sizeof(response);
-		rv = send_vendor_command(td, VENDOR_CC_CCD,
-					 &payload, sizeof(payload),
+		rv = send_vendor_command(td, command,
+					 &poll_type, sizeof(poll_type),
 					 &response, &response_size);
 
 		if (((rv != VENDOR_RC_SUCCESS) && (rv != VENDOR_RC_IN_PROGRESS))
@@ -1705,6 +1677,53 @@ static void process_ccd_state(struct transfer_descriptor *td, int ccd_unlock,
 
 		usleep(500 * 1000); /* Poll every half a second. */
 	}
+
+}
+
+static void process_ccd_state(struct transfer_descriptor *td, int ccd_unlock,
+			      int ccd_open, int ccd_lock)
+{
+	uint8_t payload;
+	uint8_t response;
+	size_t response_size;
+	int rv;
+
+	if (ccd_unlock)
+		payload = CCDV_UNLOCK;
+	else if (ccd_open)
+		payload = CCDV_OPEN;
+	else
+		payload = CCDV_LOCK;
+
+	response_size = sizeof(response);
+	rv = send_vendor_command(td, VENDOR_CC_CCD,
+				 &payload, sizeof(payload),
+				 &response, &response_size);
+
+	/*
+	 * If password is required - try sending the same subcommand
+	 * accompanied by user password.
+	 */
+	if (rv == VENDOR_RC_PASSWORD_REQUIRED)
+		rv = common_process_password(td, payload);
+
+	if (rv == VENDOR_RC_SUCCESS)
+		return;
+
+	if (rv != VENDOR_RC_IN_PROGRESS) {
+		fprintf(stderr, "Error: rv %d, response %d\n",
+			rv, response_size ? response : 0);
+		exit(update_error);
+	}
+
+	/*
+	 * Physical presence process started, poll for the state the user
+	 * asked for. Only two subcommands would return 'IN_PROGRESS'.
+	 */
+	if (ccd_unlock)
+		poll_for_pp(td, VENDOR_CC_CCD, CCDV_PP_POLL_UNLOCK);
+	else
+		poll_for_pp(td, VENDOR_CC_CCD, CCDV_PP_POLL_OPEN);
 }
 
 static void process_bid(struct transfer_descriptor *td,