TCPMv1: Remove cable discovery support

TCPMv1 cable discovery support has not been used for some time. Remove
it to facilitate refactoring 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: I6500f56418a860c343e8159f33151e765512067c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3887962
Reviewed-by: Diana Z <dzigterman@chromium.org>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>

2 files changed, 10 insertions, 153 deletions

diff --git a/common/usb_pd_policy.c b/common/usb_pd_policy.c
index d39aaf4172..c63cde6301 100644
--- a/common/usb_pd_policy.c
+++ b/common/usb_pd_policy.c
@@ -102,58 +102,6 @@ uint8_t pd_get_src_cap_cnt(int port)
 	return pd_src_cap_cnt[port];
 }
 
-static struct pd_cable cable[CONFIG_USB_PD_PORT_MAX_COUNT];
-
-enum pd_rev_type get_usb_pd_cable_revision(int port)
-{
-	return cable[port].rev;
-}
-
-bool consume_sop_prime_repeat_msg(int port, uint8_t msg_id)
-{
-	if (cable[port].last_sop_p_msg_id != msg_id) {
-		cable[port].last_sop_p_msg_id = msg_id;
-		return false;
-	}
-	CPRINTF("C%d SOP Prime repeat msg_id %d\n", port, msg_id);
-	return true;
-}
-
-bool consume_sop_prime_prime_repeat_msg(int port, uint8_t msg_id)
-{
-	if (cable[port].last_sop_p_p_msg_id != msg_id) {
-		cable[port].last_sop_p_p_msg_id = msg_id;
-		return false;
-	}
-	CPRINTF("C%d SOP Prime Prime repeat msg_id %d\n", port, msg_id);
-	return true;
-}
-
-__maybe_unused static uint8_t is_sop_prime_ready(int port)
-{
-	/*
-	 * Ref: USB PD 3.0 sec 2.5.4: When an Explicit Contract is in place the
-	 * VCONN Source (either the DFP or the UFP) can communicate with the
-	 * Cable Plug(s) using SOP’/SOP’’ Packets
-	 *
-	 * Ref: USB PD 2.0 sec 2.4.4: When an Explicit Contract is in place the
-	 * DFP (either the Source or the Sink) can communicate with the
-	 * Cable Plug(s) using SOP’/SOP” Packets.
-	 * Sec 3.6.11 : Before communicating with a Cable Plug a Port Should
-	 * ensure that it is the Vconn Source
-	 */
-	return (pd_get_vconn_state(port) &&
-		(IS_ENABLED(CONFIG_USB_PD_REV30) ||
-		 (pd_get_data_role(port) == PD_ROLE_DFP)));
-}
-
-void reset_pd_cable(int port)
-{
-	memset(&cable[port], 0, sizeof(cable[port]));
-	cable[port].last_sop_p_msg_id = INVALID_MSG_ID_COUNTER;
-	cable[port].last_sop_p_p_msg_id = INVALID_MSG_ID_COUNTER;
-}
-
 #ifdef CONFIG_USB_PD_ALT_MODE
 
 #ifdef CONFIG_USB_PD_ALT_MODE_DFP
@@ -235,15 +183,6 @@ static int process_am_discover_ident_sop(int port, int cnt, uint32_t head,
 	return dfp_discover_svids(payload);
 }
 
-static int process_am_discover_ident_sop_prime(int port, int cnt, uint32_t head,
-					       uint32_t *payload)
-{
-	dfp_consume_identity(port, TCPCI_MSG_SOP_PRIME, cnt, payload);
-	cable[port].rev = PD_HEADER_REV(head);
-
-	return dfp_discover_svids(payload);
-}
-
 static int process_am_discover_svids(int port, int cnt, uint32_t *payload,
 				     enum tcpci_msg_type sop,
 				     enum tcpci_msg_type *rtype)
@@ -341,15 +280,9 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
 		switch (cmd) {
 #ifdef CONFIG_USB_PD_ALT_MODE_DFP
 		case CMD_DISCOVER_IDENT:
-			/* Received a SOP' Discover Ident msg */
-			if (sop == TCPCI_MSG_SOP_PRIME) {
-				rsize = process_am_discover_ident_sop_prime(
-					port, cnt, head, payload);
-				/* Received a SOP Discover Ident Message */
-			} else {
-				rsize = process_am_discover_ident_sop(
-					port, cnt, head, payload, rtype);
-			}
+			/* Received a SOP Discover Ident Message */
+			rsize = process_am_discover_ident_sop(port, cnt, head,
+							      payload, rtype);
 			break;
 		case CMD_DISCOVER_SVID:
 			rsize = process_am_discover_svids(port, cnt, payload,
@@ -453,7 +386,6 @@ int pd_svdm(int port, int cnt, uint32_t *payload, uint32_t **rpayload,
 			rsize = 0;
 		}
 	} else if (cmd_type == CMDT_RSP_NAK) {
-		/* Passive cable Nacked for Discover SVID */
 		rsize = 0;
 #endif /* CONFIG_USB_PD_ALT_MODE_DFP */
 	} else {
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index 780cd6ce34..80d3b400da 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -367,9 +367,6 @@ int pd_get_rev(int port, enum tcpci_msg_type type)
 	/* TCPMv1 Only stores PD revision for SOP and SOP' types */
 	ASSERT(type < NUM_SOP_STAR_TYPES - 1);
 
-	if (type == TCPCI_MSG_SOP_PRIME)
-		return get_usb_pd_cable_revision(port);
-
 	return pd[port].rev;
 #else
 	return PD_REV20;
@@ -379,9 +376,6 @@ int pd_get_rev(int port, enum tcpci_msg_type type)
 int pd_get_vdo_ver(int port, enum tcpci_msg_type type)
 {
 #ifdef CONFIG_USB_PD_REV30
-	if (type == TCPCI_MSG_SOP_PRIME)
-		return vdo_ver[get_usb_pd_cable_revision(port)];
-
 	return vdo_ver[pd[port].rev];
 #else
 	return VDM_VER10;
@@ -691,24 +685,15 @@ static bool consume_sop_repeat_message(int port, uint8_t msg_id)
  * @param port USB PD TCPC port number
  * @param msg_header Message Header containing the RX message ID
  * @return True if the received message is a duplicate one, False otherwise.
- *
- * From USB PD version 1.3 section 6.7.1, the port which communicates
- * using SOP* Packets Shall maintain copies of the last MessageID for
- * each type of SOP* it uses.
  */
 static bool consume_repeat_message(int port, uint32_t msg_header)
 {
 	uint8_t msg_id = PD_HEADER_ID(msg_header);
-	enum tcpci_msg_type sop = PD_HEADER_GET_SOP(msg_header);
 
 	/* If repeat message ignore, except softreset control request. */
 	if (PD_HEADER_TYPE(msg_header) == PD_CTRL_SOFT_RESET &&
 	    PD_HEADER_CNT(msg_header) == 0) {
 		return false;
-	} else if (sop == TCPCI_MSG_SOP_PRIME) {
-		return consume_sop_prime_repeat_msg(port, msg_id);
-	} else if (sop == TCPCI_MSG_SOP_PRIME_PRIME) {
-		return consume_sop_prime_prime_repeat_msg(port, msg_id);
 	} else {
 		return consume_sop_repeat_message(port, msg_id);
 	}
@@ -806,7 +791,6 @@ static inline void set_state(int port, enum pd_states next_state)
 		if (last_state != PD_STATE_SNK_DISCONNECTED_DEBOUNCE &&
 		    last_state != PD_STATE_SRC_DISCONNECTED_DEBOUNCE) {
 			pd[port].flags &= ~PD_FLAGS_RESET_ON_DISCONNECT_MASK;
-			reset_pd_cable(port);
 		}
 
 		/* Clear the input current limit */
@@ -2141,7 +2125,6 @@ static void pd_vdm_send_state_machine(int port)
 {
 	int res;
 	uint16_t header;
-	enum tcpci_msg_type msg_type = pd[port].xmit_type;
 
 	switch (pd[port].vdm_state) {
 	case VDM_STATE_READY:
@@ -2158,63 +2141,13 @@ static void pd_vdm_send_state_machine(int port)
 		if (pdo_busy(port))
 			break;
 
-		/*
-		 * To communicate with the cable plug, an explicit contract
-		 * should be established, VCONN should be enabled and data role
-		 * that can communicate with the cable plug should be in place.
-		 * For USB3.0, UFP/DFP can communicate whereas in case of
-		 * USB2.0 only DFP can talk to the cable plug.
-		 *
-		 * For communication between USB2.0 UFP and cable plug,
-		 * data role swap takes place during source and sink
-		 * negotiation and in case of failure, a soft reset is issued.
-		 */
-		if ((msg_type == TCPCI_MSG_SOP_PRIME) ||
-		    (msg_type == TCPCI_MSG_SOP_PRIME_PRIME)) {
-			/* Prepare SOP'/SOP'' header and send VDM */
-			header = PD_HEADER(PD_DATA_VENDOR_DEF,
-					   PD_PLUG_FROM_DFP_UFP, 0,
-					   pd[port].msg_id,
-					   (int)pd[port].vdo_count,
-					   pd_get_rev(port, TCPCI_MSG_SOP), 0);
-			res = pd_transmit(port, msg_type, header,
-					  pd[port].vdo_data, AMS_START);
-			/*
-			 * In the case of SOP', if there is no response from
-			 * the cable, it's a non-emark cable and therefore the
-			 * pd flow should continue irrespective of cable
-			 * response, sending discover_identity so the pd flow
-			 * remains intact.
-			 *
-			 * In the case of SOP'', if there is no response from
-			 * the cable, exit Thunderbolt-Compatible mode
-			 * discovery, reset the mux state since, the mux will
-			 * be set to a safe state before entering
-			 * Thunderbolt-Compatible mode and enter the default
-			 * mode.
-			 */
-			if (res < 0) {
-				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_SID_PD, 1, CMD_DISCOVER_SVID);
-				res = pd_transmit(port, TCPCI_MSG_SOP, header,
-						  pd[port].vdo_data, AMS_START);
-				reset_pd_cable(port);
-			}
-		} else {
-			/* Prepare SOP header and send VDM */
-			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);
-			res = pd_transmit(port, TCPCI_MSG_SOP, header,
-					  pd[port].vdo_data, AMS_START);
-		}
+		/* Prepare SOP header and send VDM */
+		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);
+		res = pd_transmit(port, TCPCI_MSG_SOP, header,
+				  pd[port].vdo_data, AMS_START);
 
 		if (res < 0) {
 			pd[port].vdm_state = VDM_STATE_ERR_SEND;
@@ -3378,8 +3311,6 @@ void pd_task(void *u)
 			set_state(port, PD_STATE_SRC_STARTUP);
 			break;
 		case PD_STATE_SRC_STARTUP:
-			/* Reset cable attributes and flags */
-			reset_pd_cable(port);
 			/* Wait for power source to enable */
 			if (pd[port].last_state != pd[port].task_state) {
 				pd[port].flags |= PD_FLAGS_CHECK_IDENTITY;
@@ -3954,9 +3885,6 @@ void pd_task(void *u)
 				pd[port].flags |= PD_FLAGS_CHECK_PR_ROLE |
 						  PD_FLAGS_CHECK_DR_ROLE |
 						  PD_FLAGS_CHECK_IDENTITY;
-				/* Reset cable attributes and flags */
-				reset_pd_cable(port);
-
 				if (new_cc_state == PD_CC_DFP_DEBUG_ACC)
 					pd[port].flags |=
 						PD_FLAGS_TS_DTS_PARTNER;
@@ -4783,8 +4711,6 @@ static void pd_chipset_startup(void)
 	for (i = 0; i < board_get_usb_pd_port_count(); i++) {
 		pd_set_dual_role_no_wakeup(i, PD_DRP_TOGGLE_OFF);
 		pd[i].flags |= PD_FLAGS_CHECK_IDENTITY;
-		/* Reset cable attributes and flags */
-		reset_pd_cable(i);
 		task_set_event(PD_PORT_TO_TASK_ID(i),
 			       PD_EVENT_POWER_STATE_CHANGE |
 				       PD_EVENT_UPDATE_DUAL_ROLE);
@@ -5310,5 +5236,4 @@ DECLARE_HOST_COMMAND(EC_CMD_USB_PD_FW_UPDATE, hc_remote_flash, EC_VER_MASK(0));
 #endif /* CONFIG_HOSTCMD_FLASHPD */
 
 #endif /* HAS_TASK_HOSTCMD */
-
 #endif /* CONFIG_COMMON_RUNTIME */