usb: typec: tcpm: Determine common SVDM Version

PD Spec Revision 3.0 Version 2.0 + ECNs 2020-12-10
  6.4.4.2.3 Structured VDM Version
  "The Structured VDM Version field of the Discover Identity Command
  sent and received during VDM discovery Shall be used to determine the
  lowest common Structured VDM Version supported by the Port Partners or
  Cable Plug and Shall continue to operate using this Specification
  Revision until they are Detached."

Also clear the fields newly defined in SVDM version 2.0 if the
negotiated SVDM version is 1.0.
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210205033415.3320439-4-kyletso@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/tcpm.c

@@ -1475,8 +1475,10 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			const u32 *p, int cnt, u32 *response,
 			enum adev_actions *adev_action)
 {
+	struct typec_port *typec = port->typec_port;
 	struct typec_altmode *pdev;
 	struct pd_mode_data *modep;
+	int svdm_version;
 	int rlen = 0;
 	int cmd_type;
 	int cmd;
@@ -1493,6 +1495,10 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 	pdev = typec_match_altmode(port->partner_altmode, ALTMODE_DISCOVERY_MAX,
 				   PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));
 
+	svdm_version = typec_get_negotiated_svdm_version(typec);
+	if (svdm_version < 0)
+		return 0;
+
 	switch (cmd_type) {
 	case CMDT_INIT:
 		switch (cmd) {
@@ -1500,10 +1506,22 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			if (PD_VDO_VID(p[0]) != USB_SID_PD)
 				break;
 
+			if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
+				typec_partner_set_svdm_version(port->partner,
+							       PD_VDO_SVDM_VER(p[0]));
 			/* 6.4.4.3.1: Only respond as UFP (device) */
 			if (port->data_role == TYPEC_DEVICE &&
 			    port->nr_snk_vdo) {
-				for (i = 0; i <  port->nr_snk_vdo; i++)
+				/*
+				 * Product Type DFP and Connector Type are not defined in SVDM
+				 * version 1.0 and shall be set to zero.
+				 */
+				if (typec_get_negotiated_svdm_version(typec) < SVDM_VER_2_0)
+					response[1] = port->snk_vdo[0] & ~IDH_DFP_MASK
+						      & ~IDH_CONN_MASK;
+				else
+					response[1] = port->snk_vdo[0];
+				for (i = 1; i <  port->nr_snk_vdo; i++)
 					response[i + 1] = port->snk_vdo[i];
 				rlen = port->nr_snk_vdo + 1;
 			}
@@ -1532,6 +1550,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			response[0] = p[0] | VDO_CMDT(CMDT_RSP_BUSY);
 			rlen = 1;
 		}
+		response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
+			      (VDO_SVDM_VERS(typec_get_negotiated_svdm_version(typec)));
 		break;
 	case CMDT_RSP_ACK:
 		/* silently drop message if we are not connected */
@@ -1542,19 +1562,22 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 
 		switch (cmd) {
 		case CMD_DISCOVER_IDENT:
+			if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
+				typec_partner_set_svdm_version(port->partner,
+							       PD_VDO_SVDM_VER(p[0]));
 			/* 6.4.4.3.1 */
 			svdm_consume_identity(port, p, cnt);
-			response[0] = VDO(USB_SID_PD, 1, SVDM_VER_1_0, CMD_DISCOVER_SVID);
+			response[0] = VDO(USB_SID_PD, 1, typec_get_negotiated_svdm_version(typec),
+					  CMD_DISCOVER_SVID);
 			rlen = 1;
 			break;
 		case CMD_DISCOVER_SVID:
 			/* 6.4.4.3.2 */
 			if (svdm_consume_svids(port, p, cnt)) {
-				response[0] = VDO(USB_SID_PD, 1, SVDM_VER_1_0,
-						  CMD_DISCOVER_SVID);
+				response[0] = VDO(USB_SID_PD, 1, svdm_version, CMD_DISCOVER_SVID);
 				rlen = 1;
 			} else if (modep->nsvids && supports_modal(port)) {
-				response[0] = VDO(modep->svids[0], 1, SVDM_VER_1_0,
+				response[0] = VDO(modep->svids[0], 1, svdm_version,
 						  CMD_DISCOVER_MODES);
 				rlen = 1;
 			}
@@ -1565,7 +1588,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			modep->svid_index++;
 			if (modep->svid_index < modep->nsvids) {
 				u16 svid = modep->svids[modep->svid_index];
-				response[0] = VDO(svid, 1, SVDM_VER_1_0, CMD_DISCOVER_MODES);
+				response[0] = VDO(svid, 1, svdm_version, CMD_DISCOVER_MODES);
 				rlen = 1;
 			} else {
 				tcpm_register_partner_altmodes(port);
@@ -1592,6 +1615,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			/* Unrecognized SVDM */
 			response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
 			rlen = 1;
+			response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
+				      (VDO_SVDM_VERS(svdm_version));
 			break;
 		}
 		break;
@@ -1611,6 +1636,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			/* Unrecognized SVDM */
 			response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
 			rlen = 1;
+			response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
+				      (VDO_SVDM_VERS(svdm_version));
 			break;
 		}
 		port->vdm_sm_running = false;
@@ -1618,6 +1645,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 	default:
 		response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
 		rlen = 1;
+		response[0] = (response[0] & ~VDO_SVDM_VERS_MASK) |
+			      (VDO_SVDM_VERS(svdm_version));
 		port->vdm_sm_running = false;
 		break;
 	}
@@ -1695,7 +1724,13 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
 			break;
 		case ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL:
 			if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
-				response[0] = VDO(adev->svid, 1, SVDM_VER_1_0, CMD_EXIT_MODE);
+				int svdm_version = typec_get_negotiated_svdm_version(
+									port->typec_port);
+				if (svdm_version < 0)
+					break;
+
+				response[0] = VDO(adev->svid, 1, svdm_version,
+						  CMD_EXIT_MODE);
 				response[0] |= VDO_OPOS(adev->mode);
 				rlen = 1;
 			}
@@ -1722,14 +1757,19 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
 static void tcpm_send_vdm(struct tcpm_port *port, u32 vid, int cmd,
 			  const u32 *data, int count)
 {
+	int svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
 	u32 header;
 
+	if (svdm_version < 0)
+		return;
+
 	if (WARN_ON(count > VDO_MAX_SIZE - 1))
 		count = VDO_MAX_SIZE - 1;
 
 	/* set VDM header with VID & CMD */
 	header = VDO(vid, ((vid & USB_SID_PD) == USB_SID_PD) ?
-			1 : (PD_VDO_CMD(cmd) <= CMD_ATTENTION), SVDM_VER_1_0, cmd);
+			1 : (PD_VDO_CMD(cmd) <= CMD_ATTENTION),
+			svdm_version, cmd);
 	tcpm_queue_vdm(port, header, data, count);
 }
 
@@ -2022,9 +2062,14 @@ static int tcpm_validate_caps(struct tcpm_port *port, const u32 *pdo,
 static int tcpm_altmode_enter(struct typec_altmode *altmode, u32 *vdo)
 {
 	struct tcpm_port *port = typec_altmode_get_drvdata(altmode);
+	int svdm_version;
 	u32 header;
 
-	header = VDO(altmode->svid, vdo ? 2 : 1, SVDM_VER_1_0, CMD_ENTER_MODE);
+	svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	header = VDO(altmode->svid, vdo ? 2 : 1, svdm_version, CMD_ENTER_MODE);
 	header |= VDO_OPOS(altmode->mode);
 
 	tcpm_queue_vdm_unlocked(port, header, vdo, vdo ? 1 : 0);
@@ -2034,9 +2079,14 @@ static int tcpm_altmode_enter(struct typec_altmode *altmode, u32 *vdo)
 static int tcpm_altmode_exit(struct typec_altmode *altmode)
 {
 	struct tcpm_port *port = typec_altmode_get_drvdata(altmode);
+	int svdm_version;
 	u32 header;
 
-	header = VDO(altmode->svid, 1, SVDM_VER_1_0, CMD_EXIT_MODE);
+	svdm_version = typec_get_negotiated_svdm_version(port->typec_port);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	header = VDO(altmode->svid, 1, svdm_version, CMD_EXIT_MODE);
 	header |= VDO_OPOS(altmode->mode);
 
 	tcpm_queue_vdm_unlocked(port, header, NULL, 0);
@@ -5977,6 +6027,7 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
 	port->typec_caps.fwnode = tcpc->fwnode;
 	port->typec_caps.revision = 0x0120;	/* Type-C spec release 1.2 */
 	port->typec_caps.pd_revision = 0x0300;	/* USB-PD spec release 3.0 */
+	port->typec_caps.svdm_version = SVDM_VER_2_0;
 	port->typec_caps.driver_data = port;
 	port->typec_caps.ops = &tcpm_ops;
 	port->typec_caps.orientation_aware = 1;