TCPMv1: Remove TBT and USB4 support

TCPMv1 has not been used for TBT or USB4 for some time. Remove this
support to make it easier to refactor TBT and USB4 code.

LOW_COVERAGE_REASON=TCPMv1 is known to be buggy but is deprecated; its
behavior is hard to describe but should not be changed.
BUG=b:244218024
TEST=make BOARD=careena; DP monitor behavior same as ToT
BRANCH=none

Signed-off-by: Abe Levkoy <alevkoy@chromium.org>
Change-Id: Ia02ce7a2500b83e3147ec5737134a009a59ea288
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3887961
Reviewed-by: Diana Z <dzigterman@chromium.org>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>

3 files changed, 5 insertions, 553 deletions

diff --git a/common/usb_pd_policy.c b/common/usb_pd_policy.c
index dbea31bf6d..d39aaf4172 100644
--- a/common/usb_pd_policy.c
+++ b/common/usb_pd_policy.c
@@ -154,24 +154,6 @@ void reset_pd_cable(int port)
 	cable[port].last_sop_p_p_msg_id = INVALID_MSG_ID_COUNTER;
 }
 
-bool should_enter_usb4_mode(int port)
-{
-	return IS_ENABLED(CONFIG_USB_PD_USB4) &&
-	       cable[port].flags & CABLE_FLAGS_ENTER_USB_MODE;
-}
-
-void enable_enter_usb4_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_USB4))
-		cable[port].flags |= CABLE_FLAGS_ENTER_USB_MODE;
-}
-
-void disable_enter_usb4_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_USB4))
-		cable[port].flags &= ~CABLE_FLAGS_ENTER_USB_MODE;
-}
-
 #ifdef CONFIG_USB_PD_ALT_MODE
 
 #ifdef CONFIG_USB_PD_ALT_MODE_DFP
@@ -181,168 +163,6 @@ static struct pd_discovery discovery[CONFIG_USB_PD_PORT_MAX_COUNT]
 static struct partner_active_modes partner_amodes[CONFIG_USB_PD_PORT_MAX_COUNT]
 						 [AMODE_TYPE_COUNT];
 
-static bool is_vdo_present(int cnt, int index)
-{
-	return cnt > index;
-}
-
-static bool is_modal(int port, int cnt, const uint32_t *payload)
-{
-	return is_vdo_present(cnt, VDO_INDEX_IDH) &&
-	       PD_IDH_IS_MODAL(payload[VDO_INDEX_IDH]);
-}
-
-static bool is_tbt_compat_mode(int port, int cnt, const uint32_t *payload)
-{
-	/*
-	 * Ref: USB Type-C cable and connector specification
-	 * F.2.5 TBT3 Device Discover Mode Responses
-	 */
-	return is_vdo_present(cnt, VDO_INDEX_IDH) &&
-	       PD_VDO_RESP_MODE_INTEL_TBT(payload[VDO_INDEX_IDH]);
-}
-
-static bool cable_supports_tbt_speed(int port)
-{
-	enum tbt_compat_cable_speed tbt_cable_speed = get_tbt_cable_speed(port);
-
-	return (tbt_cable_speed == TBT_SS_TBT_GEN3 ||
-		tbt_cable_speed == TBT_SS_U32_GEN1_GEN2);
-}
-
-static bool is_tbt_compat_enabled(int port)
-{
-	return (IS_ENABLED(CONFIG_USB_PD_TBT_COMPAT_MODE) &&
-		(cable[port].flags & CABLE_FLAGS_TBT_COMPAT_ENABLE));
-}
-
-static void enable_tbt_compat_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_TBT_COMPAT_MODE))
-		cable[port].flags |= CABLE_FLAGS_TBT_COMPAT_ENABLE;
-}
-
-static inline void disable_tbt_compat_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_TBT_COMPAT_MODE))
-		cable[port].flags &= ~CABLE_FLAGS_TBT_COMPAT_ENABLE;
-}
-
-static inline void limit_tbt_cable_speed(int port)
-{
-	/* Cable flags are cleared when cable reset is called */
-	cable[port].flags |= CABLE_FLAGS_TBT_COMPAT_LIMIT_SPEED;
-}
-
-static inline bool is_limit_tbt_cable_speed(int port)
-{
-	return !!(cable[port].flags & CABLE_FLAGS_TBT_COMPAT_LIMIT_SPEED);
-}
-
-static bool is_intel_svid(int port, enum tcpci_msg_type type)
-{
-	int i;
-
-	for (i = 0; i < discovery[port][type].svid_cnt; i++) {
-		if (pd_get_svid(port, i, type) == USB_VID_INTEL)
-			return true;
-	}
-
-	return false;
-}
-
-static inline bool is_usb4_mode_enabled(int port)
-{
-	return (IS_ENABLED(CONFIG_USB_PD_USB4) &&
-		(cable[port].flags & CABLE_FLAGS_USB4_CAPABLE));
-}
-
-static inline void enable_usb4_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_USB4))
-		cable[port].flags |= CABLE_FLAGS_USB4_CAPABLE;
-}
-
-static inline void disable_usb4_mode(int port)
-{
-	if (IS_ENABLED(CONFIG_USB_PD_USB4))
-		cable[port].flags &= ~CABLE_FLAGS_USB4_CAPABLE;
-}
-
-/*
- * Ref: USB Type-C Cable and Connector Specification
- * Figure 5-1 USB4 Discovery and Entry Flow Model.
- *
- * Note: USB Type-C Cable and Connector Specification
- * doesn't include details for Revision 2 cables.
- *
- *                         Passive Cable
- *                                |
- *                -----------------------------------
- *                |                                 |
- *           Revision 2                        Revision 3
- *          USB Signalling                   USB Signalling
- *             |                                     |
- *     ------------------            -------------------------
- *     |       |        |            |       |       |       |
- * USB2.0   USB3.1    USB3.1       USB3.2   USB4   USB3.2   USB2
- *   |      Gen1      Gen1 Gen2    Gen2     Gen3   Gen1       |
- *   |       |          |           |        |       |       Exit
- *   --------           ------------         --------        USB4
- *      |                    |                  |          Discovery.
- *    Exit          Is DFP Gen3 Capable?     Enter USB4
- *    USB4                  |                with respective
- *   Discovery.   --- No ---|--- Yes ---     cable speed.
- *                |                    |
- *    Enter USB4 with             Is Cable TBT3
- *    respective cable                 |
- *    speed.                 --- No ---|--- Yes ---
- *                           |                    |
- *                   Enter USB4 with        Enter USB4 with
- *                   TBT Gen2 passive       TBT Gen3 passive
- *                   cable.                 cable.
- *
- */
-static bool is_cable_ready_to_enter_usb4(int port, int cnt)
-{
-	/* TODO: USB4 enter mode for Active cables */
-	struct pd_discovery *disc = &discovery[port][TCPCI_MSG_SOP_PRIME];
-	if (IS_ENABLED(CONFIG_USB_PD_USB4) &&
-	    (get_usb_pd_cable_type(port) == IDH_PTYPE_PCABLE) &&
-	    is_vdo_present(cnt, VDO_INDEX_PTYPE_CABLE1)) {
-		switch (cable[port].rev) {
-		case PD_REV30:
-			switch (disc->identity.product_t1.p_rev30.ss) {
-			case USB_R30_SS_U40_GEN3:
-			case USB_R30_SS_U32_U40_GEN1:
-				return true;
-			case USB_R30_SS_U32_U40_GEN2:
-				/* Check if DFP is Gen 3 capable */
-				if (IS_ENABLED(CONFIG_USB_PD_TBT_GEN3_CAPABLE))
-					return false;
-				return true;
-			default:
-				disable_usb4_mode(port);
-				return false;
-			}
-		case PD_REV20:
-			switch (disc->identity.product_t1.p_rev20.ss) {
-			case USB_R20_SS_U31_GEN1_GEN2:
-				/* Check if DFP is Gen 3 capable */
-				if (IS_ENABLED(CONFIG_USB_PD_TBT_GEN3_CAPABLE))
-					return false;
-				return true;
-			default:
-				disable_usb4_mode(port);
-				return false;
-			}
-		default:
-			disable_usb4_mode(port);
-		}
-	}
-	return false;
-}
-
 void pd_dfp_discovery_init(int port)
 {
 	memset(&discovery[port], 0, sizeof(struct pd_discovery));
@@ -353,12 +173,6 @@ void pd_dfp_mode_init(int port)
 	memset(&partner_amodes[port], 0, sizeof(partner_amodes[0]));
 }
 
-static int dfp_discover_ident(uint32_t *payload)
-{
-	payload[0] = VDO(USB_SID_PD, 1, CMD_DISCOVER_IDENT);
-	return 1;
-}
-
 static int dfp_discover_svids(uint32_t *payload)
 {
 	payload[0] = VDO(USB_SID_PD, 1, CMD_DISCOVER_SVID);
@@ -410,23 +224,6 @@ static int dfp_discover_modes(int port, uint32_t *payload)
 	return 1;
 }
 
-static bool is_usb4_vdo(int port, int cnt, uint32_t *payload)
-{
-	enum idh_ptype ptype = PD_IDH_PTYPE(payload[VDO_I(IDH)]);
-
-	if (IS_PD_IDH_UFP_PTYPE(ptype)) {
-		/*
-		 * Ref: USB Type-C Cable and Connector Specification
-		 * Figure 5-1 USB4 Discovery and Entry Flow Model
-		 * Device USB4 VDO detection.
-		 */
-		return IS_ENABLED(CONFIG_USB_PD_USB4) &&
-		       is_vdo_present(cnt, VDO_INDEX_PTYPE_UFP1_VDO) &&
-		       PD_PRODUCT_IS_USB4(payload[VDO_INDEX_PTYPE_UFP1_VDO]);
-	}
-	return false;
-}
-
 static int process_am_discover_ident_sop(int port, int cnt, uint32_t head,
 					 uint32_t *payload,
 					 enum tcpci_msg_type *rtype)
@@ -435,29 +232,6 @@ static int process_am_discover_ident_sop(int port, int cnt, uint32_t head,
 	pd_dfp_mode_init(port);
 	dfp_consume_identity(port, TCPCI_MSG_SOP, cnt, payload);
 
-	if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP) && is_sop_prime_ready(port) &&
-	    board_is_tbt_usb4_port(port)) {
-		/* Enable USB4 mode if USB4 VDO present and port partner
-		 * supports USB Rev 3.0.
-		 */
-		if (is_usb4_vdo(port, cnt, payload) &&
-		    PD_HEADER_REV(head) == PD_REV30)
-			enable_usb4_mode(port);
-
-		/*
-		 * Enable Thunderbolt-compatible mode if the modal operation is
-		 * supported.
-		 */
-		if (is_modal(port, cnt, payload))
-			enable_tbt_compat_mode(port);
-
-		if (is_modal(port, cnt, payload) ||
-		    is_usb4_vdo(port, cnt, payload)) {
-			*rtype = TCPCI_MSG_SOP_PRIME;
-			return dfp_discover_ident(payload);
-		}
-	}
-
 	return dfp_discover_svids(payload);
 }
 
@@ -467,31 +241,6 @@ static int process_am_discover_ident_sop_prime(int port, int cnt, uint32_t head,
 	dfp_consume_identity(port, TCPCI_MSG_SOP_PRIME, cnt, payload);
 	cable[port].rev = PD_HEADER_REV(head);
 
-	/*
-	 * Enter USB4 mode if the cable supports USB4 operation and has USB4
-	 * VDO.
-	 */
-	if (is_usb4_mode_enabled(port) &&
-	    is_cable_ready_to_enter_usb4(port, cnt)) {
-		enable_enter_usb4_mode(port);
-		usb_mux_set_safe_mode(port);
-		/*
-		 * To change the mode of operation from USB4 the port needs to
-		 * be reconfigured.
-		 * Ref: USB Type-C Cable and Connectot Spec section 5.4.4.
-		 */
-		disable_tbt_compat_mode(port);
-		return 0;
-	}
-
-	/*
-	 * Disable Thunderbolt-compatible mode if the cable does not support
-	 * superspeed.
-	 */
-	if (is_tbt_compat_enabled(port) &&
-	    get_tbt_cable_speed(port) < TBT_SS_U31_GEN1)
-		disable_tbt_compat_mode(port);
-
 	return dfp_discover_svids(payload);
 }
 
@@ -506,132 +255,8 @@ static int process_am_discover_svids(int port, int cnt, uint32_t *payload,
 	 */
 	dfp_consume_svids(port, sop, cnt, payload);
 
-	/*
-	 * Ref: USB Type-C Cable and Connector Specification,
-	 * figure F-1: TBT3 Discovery Flow
-	 *
-	 * For USB4 mode if device or cable doesn't have Intel SVID,
-	 * disable Thunderbolt-Compatible mode directly enter USB4 mode
-	 * with USB3.2 Gen1/Gen2 speed.
-	 *
-	 * For Thunderbolt-compatible, check if 0x8087 is received for
-	 * Discover SVID SOP. If not, disable Thunderbolt-compatible mode
-	 *
-	 * If 0x8087 is not received for Discover SVID SOP' limit to TBT
-	 * passive Gen 2 cable.
-	 */
-	if (is_tbt_compat_enabled(port)) {
-		bool intel_svid = is_intel_svid(port, sop);
-		if (!intel_svid) {
-			if (is_usb4_mode_enabled(port)) {
-				disable_tbt_compat_mode(port);
-				cable[port].cable_mode_resp.tbt_cable_speed =
-					TBT_SS_U32_GEN1_GEN2;
-				enable_enter_usb4_mode(port);
-				usb_mux_set_safe_mode(port);
-				return 0;
-			}
-
-			if (sop == TCPCI_MSG_SOP_PRIME)
-				limit_tbt_cable_speed(port);
-			else
-				disable_tbt_compat_mode(port);
-		} else if (sop == TCPCI_MSG_SOP) {
-			*rtype = TCPCI_MSG_SOP_PRIME;
-			return dfp_discover_svids(payload);
-		}
-	}
-
 	return dfp_discover_modes(port, payload);
 }
-
-static int process_tbt_compat_discover_modes(int port, enum tcpci_msg_type sop,
-					     uint32_t *payload,
-					     enum tcpci_msg_type *rtype)
-{
-	int rsize;
-
-	/* Initialize transmit type to SOP */
-	*rtype = TCPCI_MSG_SOP;
-
-	/*
-	 * For active cables, Enter mode: SOP', SOP'', SOP
-	 * Ref: USB Type-C Cable and Connector Specification, figure F-1: TBT3
-	 * Discovery Flow and Section F.2.7 TBT3 Cable Enter Mode Command.
-	 */
-	if (sop == TCPCI_MSG_SOP_PRIME) {
-		/* Store Discover Mode SOP' response */
-		cable[port].cable_mode_resp.raw_value = payload[1];
-
-		if (is_usb4_mode_enabled(port)) {
-			/*
-			 * If Cable is not Thunderbolt Gen 3
-			 * capable or Thunderbolt Gen1_Gen2
-			 * capable, disable USB4 mode and
-			 * continue flow for
-			 * Thunderbolt-compatible mode
-			 */
-			if (cable_supports_tbt_speed(port)) {
-				enable_enter_usb4_mode(port);
-				usb_mux_set_safe_mode(port);
-				return 0;
-			}
-			disable_usb4_mode(port);
-		}
-
-		/*
-		 * Send TBT3 Cable Enter Mode (SOP') for active cables,
-		 * otherwise send TBT3 Device Enter Mode (SOP).
-		 */
-		if (get_usb_pd_cable_type(port) == IDH_PTYPE_ACABLE)
-			*rtype = TCPCI_MSG_SOP_PRIME;
-
-		rsize = enter_tbt_compat_mode(port, *rtype, payload);
-	} else {
-		/* Store Discover Mode SOP response */
-		cable[port].dev_mode_resp.raw_value = payload[1];
-
-		if (is_limit_tbt_cable_speed(port)) {
-			/*
-			 * Passive cable has Nacked for Discover SVID.
-			 * No need to do Discover modes of cable.
-			 * Enter into device Thunderbolt-compatible mode.
-			 */
-			rsize = enter_tbt_compat_mode(port, *rtype, payload);
-		} else {
-			/* Discover modes for SOP' */
-			discovery[port][TCPCI_MSG_SOP].svid_idx--;
-			rsize = dfp_discover_modes(port, payload);
-			*rtype = TCPCI_MSG_SOP_PRIME;
-		}
-	}
-
-	return rsize;
-}
-
-static int obj_cnt_enter_tbt_compat_mode(int port, enum tcpci_msg_type sop,
-					 uint32_t *payload,
-					 enum tcpci_msg_type *rtype)
-{
-	struct pd_discovery *disc = &discovery[port][TCPCI_MSG_SOP_PRIME];
-
-	/* Enter mode SOP' for active cables */
-	if (sop == TCPCI_MSG_SOP_PRIME) {
-		/* Check if the cable has a SOP'' controller */
-		if (disc->identity.product_t1.a_rev20.sop_p_p)
-			*rtype = TCPCI_MSG_SOP_PRIME_PRIME;
-		return enter_tbt_compat_mode(port, *rtype, payload);
-	}
-
-	/* Enter Mode SOP'' for active cables with SOP'' controller */
-	if (sop == TCPCI_MSG_SOP_PRIME_PRIME)
-		return enter_tbt_compat_mode(port, *rtype, payload);
-
-	/* Update Mux state to Thunderbolt-compatible mode. */
-	set_tbt_compat_mode_ready(port);
-	/* No response once device (and cable) acks */
-	return 0;
-}
 #endif /* CONFIG_USB_PD_ALT_MODE_DFP */
 
 int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
@@ -732,22 +357,10 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
 			break;
 		case CMD_DISCOVER_MODES:
 			dfp_consume_modes(port, sop, cnt, payload);
-			if (is_tbt_compat_enabled(port) &&
-			    is_tbt_compat_mode(port, cnt, payload)) {
-				rsize = process_tbt_compat_discover_modes(
-					port, sop, payload, rtype);
-				break;
-			}
 
 			rsize = dfp_discover_modes(port, payload);
 			/* enter the default mode for DFP */
 			if (!rsize) {
-				/*
-				 * Disabling Thunderbolt-Compatible mode if
-				 * discover mode response doesn't include Intel
-				 * SVID.
-				 */
-				disable_tbt_compat_mode(port);
 				payload[0] = pd_dfp_enter_mode(
 					port, TCPCI_MSG_SOP, 0, 0);
 				if (payload[0])
@@ -755,14 +368,7 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
 			}
 			break;
 		case CMD_ENTER_MODE:
-			if (is_tbt_compat_enabled(port)) {
-				rsize = obj_cnt_enter_tbt_compat_mode(
-					port, sop, payload, rtype);
-				/*
-				 * Continue with PD flow if
-				 * Thunderbolt-compatible mode is disabled.
-				 */
-			} else if (!modep) {
+			if (!modep) {
 				rsize = 0;
 			} else {
 				if (!modep->opos)
@@ -848,14 +454,7 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
 		}
 	} else if (cmd_type == CMDT_RSP_NAK) {
 		/* Passive cable Nacked for Discover SVID */
-		if (cmd == CMD_DISCOVER_SVID && is_tbt_compat_enabled(port) &&
-		    sop == TCPCI_MSG_SOP_PRIME &&
-		    get_usb_pd_cable_type(port) == IDH_PTYPE_PCABLE) {
-			limit_tbt_cable_speed(port);
-			rsize = dfp_discover_modes(port, payload);
-		} else {
-			rsize = 0;
-		}
+		rsize = 0;
 #endif /* CONFIG_USB_PD_ALT_MODE_DFP */
 	} else {
 		CPRINTF("ERR:CMDT:%d\n", cmd);
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index ff78c55b13..780cd6ce34 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -331,7 +331,6 @@ static const char *const pd_state_names[] = {
 	"BIST_RX",
 	"BIST_TX",
 	"DRP_AUTO_TOGGLE",
-	"ENTER_USB",
 };
 BUILD_ASSERT(ARRAY_SIZE(pd_state_names) == PD_STATE_COUNT);
 #endif
@@ -1664,12 +1663,6 @@ static void handle_data_request(int port, uint32_t head, uint32_t *payload)
 #ifdef CONFIG_USB_PD_REV30
 	case PD_DATA_BATTERY_STATUS:
 		break;
-		/* TODO : Add case PD_DATA_RESET for exiting USB4 */
-
-		/*
-		 * TODO : Add case PD_DATA_ENTER_USB to accept or reject
-		 * Enter_USB request from port partner.
-		 */
 #endif
 	case PD_DATA_VENDOR_DEF:
 		handle_vdm_request(port, cnt, payload, head);
@@ -1835,21 +1828,6 @@ static void handle_ctrl_request(int port, uint32_t head, uint32_t *payload)
 		break;
 #endif
 	case PD_CTRL_REJECT:
-		if (pd[port].task_state == PD_STATE_ENTER_USB) {
-			if (!IS_ENABLED(CONFIG_USBC_SS_MUX))
-				break;
-
-			/*
-			 * Since Enter USB sets the mux state to SAFE mode,
-			 * resetting the mux state back to USB mode on
-			 * recieveing a NACK.
-			 */
-			usb_mux_set(port, USB_PD_MUX_USB_ENABLED,
-				    USB_SWITCH_CONNECT, pd[port].polarity);
-
-			set_state(port, READY_RETURN_STATE(port));
-			break;
-		}
 	case PD_CTRL_WAIT:
 		if (pd[port].task_state == PD_STATE_DR_SWAP) {
 			if (type == PD_CTRL_WAIT) /* try again ... */
@@ -1912,20 +1890,7 @@ static void handle_ctrl_request(int port, uint32_t head, uint32_t *payload)
 #endif
 		break;
 	case PD_CTRL_ACCEPT:
-		if (pd[port].task_state == PD_STATE_ENTER_USB) {
-			if (!IS_ENABLED(CONFIG_USBC_SS_MUX))
-				break;
-
-			/* Connect the SBU and USB lines to the connector */
-			if (IS_ENABLED(CONFIG_USBC_PPC_SBU))
-				ppc_set_sbu(port, 1);
-
-			/* Set usb mux to USB4 mode */
-			usb_mux_set(port, USB_PD_MUX_USB4_ENABLED,
-				    USB_SWITCH_CONNECT, pd[port].polarity);
-
-			set_state(port, READY_RETURN_STATE(port));
-		} else if (pd[port].task_state == PD_STATE_SOFT_RESET) {
+		if (pd[port].task_state == PD_STATE_SOFT_RESET) {
 			/*
 			 * For the case that we sent soft reset in SNK_DISCOVERY
 			 * on startup due to VBUS never low, clear the flag.
@@ -2172,45 +2137,6 @@ static uint64_t vdm_get_ready_timeout(uint32_t vdm_hdr)
 	return timeout;
 }
 
-static void exit_tbt_mode_sop_prime(int port)
-{
-	/* Exit Thunderbolt-Compatible mode SOP' */
-	uint16_t header;
-	int opos;
-
-	if (!IS_ENABLED(CONFIG_USB_PD_TBT_COMPAT_MODE))
-		return;
-
-	opos = pd_alt_mode(port, TCPCI_MSG_SOP, USB_VID_INTEL);
-	if (opos <= 0)
-		return;
-
-	CPRINTS("C%d Cable exiting TBT Compat mode", port);
-	/*
-	 * Note: TCPMv2 contemplates separate discovery structures for each SOP
-	 * type. TCPMv1 only uses one discovery structure, so all accesses
-	 * specify TCPCI_MSG_SOP.
-	 */
-	if (pd_dfp_exit_mode(port, TCPCI_MSG_SOP, USB_VID_INTEL, opos))
-		usb_mux_set_safe_mode(port);
-	else
-		return;
-
-	header = PD_HEADER(PD_DATA_VENDOR_DEF, pd[port].power_role,
-			   pd[port].data_role, pd[port].msg_id,
-			   (int)pd[port].vdo_count,
-			   pd_get_rev(port, TCPCI_MSG_SOP), 0);
-
-	pd[port].vdo_data[0] =
-		VDO(USB_VID_INTEL, 1, CMD_EXIT_MODE | VDO_OPOS(opos));
-
-	pd_transmit(port, TCPCI_MSG_SOP_PRIME, header, pd[port].vdo_data,
-		    AMS_START);
-
-	usb_mux_set(port, USB_PD_MUX_USB_ENABLED, USB_SWITCH_CONNECT,
-		    polarity_rm_dts(pd_get_polarity(port)));
-}
-
 static void pd_vdm_send_state_machine(int port)
 {
 	int res;
@@ -2273,15 +2199,8 @@ static void pd_vdm_send_state_machine(int port)
 					pd[port].data_role, pd[port].msg_id,
 					(int)pd[port].vdo_count,
 					pd_get_rev(port, TCPCI_MSG_SOP), 0);
-
-				if ((msg_type == TCPCI_MSG_SOP_PRIME_PRIME) &&
-				    IS_ENABLED(CONFIG_USBC_SS_MUX)) {
-					exit_tbt_mode_sop_prime(port);
-				} else if (msg_type == TCPCI_MSG_SOP_PRIME) {
-					pd[port].vdo_data[0] =
-						VDO(USB_SID_PD, 1,
-						    CMD_DISCOVER_SVID);
-				}
+				pd[port].vdo_data[0] =
+					VDO(USB_SID_PD, 1, CMD_DISCOVER_SVID);
 				res = pd_transmit(port, TCPCI_MSG_SOP, header,
 						  pd[port].vdo_data, AMS_START);
 				reset_pd_cable(port);
@@ -2790,45 +2709,6 @@ static int pd_restart_tcpc(int port)
 }
 #endif
 
-static void pd_send_enter_usb(int port, int *timeout)
-{
-	uint32_t usb4_payload;
-	uint16_t header;
-	int res;
-
-	/*
-	 * TODO: Enable Enter USB for cables (SOP').
-	 * This is needed for active cables
-	 */
-	if (!IS_ENABLED(CONFIG_USBC_SS_MUX) ||
-	    !IS_ENABLED(CONFIG_USB_PD_USB4) ||
-	    !IS_ENABLED(CONFIG_USB_PD_ALT_MODE_DFP))
-		return;
-
-	usb4_payload = get_enter_usb_msg_payload(port);
-
-	header = PD_HEADER(PD_DATA_ENTER_USB, pd[port].power_role,
-			   pd[port].data_role, pd[port].msg_id, 1, PD_REV30, 0);
-
-	res = pd_transmit(port, TCPCI_MSG_SOP, header, &usb4_payload,
-			  AMS_START);
-	if (res < 0) {
-		*timeout = 10 * MSEC;
-		/*
-		 * If failed to get goodCRC, send soft reset, otherwise ignore
-		 * failure.
-		 */
-		set_state(port, res == -1 ? PD_STATE_SOFT_RESET :
-					    READY_RETURN_STATE(port));
-		return;
-	}
-
-	/* Disable Enter USB4 mode prevent re-entry */
-	disable_enter_usb4_mode(port);
-
-	set_state(port, PD_STATE_ENTER_USB);
-}
-
 void pd_task(void *u)
 {
 	uint32_t head;
@@ -3720,15 +3600,6 @@ void pd_task(void *u)
 				break;
 			}
 
-			/*
-			 * Enter_USB if port partner and cable are
-			 * USB4 compatible.
-			 */
-			if (should_enter_usb4_mode(port)) {
-				pd_send_enter_usb(port, &timeout);
-				break;
-			}
-
 			if (!(pd[port].flags & PD_FLAGS_PING_ENABLED))
 				break;
 
@@ -4367,15 +4238,6 @@ void pd_task(void *u)
 				break;
 			}
 
-			/*
-			 * Enter_USB if port partner and cable are
-			 * USB4 compatible.
-			 */
-			if (should_enter_usb4_mode(port)) {
-				pd_send_enter_usb(port, &timeout);
-				break;
-			}
-
 			/* Sent all messages, don't need to wake very often */
 			timeout = 200 * MSEC;
 			break;
@@ -4779,14 +4641,6 @@ void pd_task(void *u)
 			break;
 		}
 #endif
-		case PD_STATE_ENTER_USB:
-			if (pd[port].last_state != pd[port].task_state) {
-				set_state_timeout(port,
-						  get_time().val +
-							  PD_T_SENDER_RESPONSE,
-						  READY_RETURN_STATE(port));
-			}
-			break;
 		default:
 			break;
 		}
diff --git a/include/usb_pd.h b/include/usb_pd.h
index 6e7a14bc31..9bae4f73af 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -894,7 +894,6 @@ enum pd_states {
 	PD_STATE_BIST_RX, /* C36 */
 	PD_STATE_BIST_TX, /* C37 */
 	PD_STATE_DRP_AUTO_TOGGLE, /* C38 */
-	PD_STATE_ENTER_USB, /* C39 */
 	/* Number of states. Not an actual state. */
 	PD_STATE_COUNT,
 };