volteer: add support for USB4 Gen3

Latest Volteer motherboards and USB4 daughterboards support USB4 Gen3
speeds. Create new USB daughterboard type in CBI FW_CONFIG to support
this configuration.

BUG=b:157483704
BRANCH=none
TEST=make buildall
TEST=Set USB DB type to 3 (USB4_GEN3), verify TBT cable speed is
reported as Gen3 to the kernel extcon-tcss-cros-ec driver.

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: I7873db70436cb9500387620a0e800c3ee79a384d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2223912
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>
Commit-Queue: Abe Levkoy <alevkoy@chromium.org>

3 files changed, 39 insertions, 12 deletions

diff --git a/baseboard/volteer/baseboard.c b/baseboard/volteer/baseboard.c
index 0964f53122..2f2f3837fd 100644
--- a/baseboard/volteer/baseboard.c
+++ b/baseboard/volteer/baseboard.c
@@ -588,6 +588,11 @@ uint8_t get_board_id(void)
 	return board_id;
 }
 
+enum usb_db_id get_usb_db_type(void)
+{
+	return usb_db_type;
+}
+
 uint32_t get_fw_config(void)
 {
 	return fw_config;
@@ -606,6 +611,7 @@ __overridable void config_volteer_gpios(void)
 {
 }
 
+static const char *db_type_prefix = "USB DB type: ";
 /*
  * Read CBI from i2c eeprom and initialize variables for board variants
  *
@@ -631,7 +637,7 @@ static void cbi_init(void)
 	/* FW config */
 	if (cbi_get_fw_config(&cbi_val) != EC_SUCCESS) {
 		CPRINTS("CBI: Read FW config failed, assuming USB4");
-		usb_db_val = USB_DB_USB4;
+		usb_db_val = USB_DB_USB4_GEN2;
 	} else {
 		fw_config = cbi_val;
 		usb_db_val = CBI_FW_CONFIG_USB_DB_TYPE(cbi_val);
@@ -639,17 +645,20 @@ static void cbi_init(void)
 
 	switch (usb_db_val) {
 	case USB_DB_NONE:
-		CPRINTS("Daughterboard type: None");
+		CPRINTS("%sNone", db_type_prefix);
+		break;
+	case USB_DB_USB4_GEN2:
+		CPRINTS("%sUSB4 Gen1/2", db_type_prefix);
 		break;
-	case USB_DB_USB4:
-		CPRINTS("Daughterboard type: USB4");
+	case USB_DB_USB4_GEN3:
+		CPRINTS("%sUSB4 Gen3", db_type_prefix);
 		break;
 	case USB_DB_USB3:
 		config_db_usb3();
-		CPRINTS("Daughterboard type: USB3");
+		CPRINTS("%sUSB3", db_type_prefix);
 		break;
 	default:
-		CPRINTS("Daughterboard ID %d not supported", usb_db_val);
+		CPRINTS("%sID %d not supported", db_type_prefix, usb_db_val);
 		usb_db_val = USB_DB_NONE;
 	}
 	usb_db_type = usb_db_val;
diff --git a/baseboard/volteer/baseboard.h b/baseboard/volteer/baseboard.h
index c7b2d17ef9..427fd714c4 100644
--- a/baseboard/volteer/baseboard.h
+++ b/baseboard/volteer/baseboard.h
@@ -274,8 +274,9 @@ enum usbc_port {
 
 enum usb_db_id {
 	USB_DB_NONE = 0,
-	USB_DB_USB4 = 1,
+	USB_DB_USB4_GEN2 = 1,
 	USB_DB_USB3 = 2,
+	USB_DB_USB4_GEN3 = 3,
 	USB_DB_COUNT
 };
 
@@ -309,6 +310,7 @@ void tcpc_alert_event(enum gpio_signal signal);
 void bc12_interrupt(enum gpio_signal signal);
 
 unsigned char get_board_id(void);
+enum usb_db_id get_usb_db_type(void);
 
 /**
  * Configure GPIOs based on the CBI board version.  Boards in the Volteer
diff --git a/board/volteer/board.c b/board/volteer/board.c
index 76b1aefff1..68515fd95e 100644
--- a/board/volteer/board.c
+++ b/board/volteer/board.c
@@ -63,9 +63,20 @@ DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
 
 __override enum tbt_compat_cable_speed board_get_max_tbt_speed(int port)
 {
-	/* Routing length exceeds 205mm prior to connection to re-timer */
-	if (port == USBC_PORT_C1)
-		return TBT_SS_U32_GEN1_GEN2;
+	enum usb_db_id usb_db_type = get_usb_db_type();
+
+	if (port == USBC_PORT_C1) {
+		if (usb_db_type == USB_DB_USB4_GEN2) {
+			/*
+			 * Older boards violate 205mm trace length prior
+			 * to connection to the re-timer and only support up
+			 * to GEN2 speeds.
+			 */
+			return TBT_SS_U32_GEN1_GEN2;
+		} else if (usb_db_type == USB_DB_USB4_GEN3) {
+			return TBT_SS_TBT_GEN3;
+		}
+	}
 
 	/*
 	 * Thunderbolt-compatible mode not supported
@@ -78,13 +89,18 @@ __override enum tbt_compat_cable_speed board_get_max_tbt_speed(int port)
 
 __override bool board_is_tbt_usb4_port(int port)
 {
+	enum usb_db_id usb_db_type = get_usb_db_type();
+
 	/*
-	 * On Proto-1 only Port 1 supports TBT & USB4
+	 * Volteer reference design only supports TBT & USB4 on port 1
+	 * if the USB4 DB is present.
 	 *
 	 * TODO (b/147732807): All the USB-C ports need to support same
 	 * features. Need to fix once USB-C feature set is known for Volteer.
 	 */
-	return port == USBC_PORT_C1;
+	return ((port == USBC_PORT_C1)
+		&& ((usb_db_type == USB_DB_USB4_GEN2)
+			|| (usb_db_type == USB_DB_USB4_GEN3)));
 }
 
 /******************************************************************************/