usb: typec: tcpm: Notify the tcpc to start connection-detection for SRPs

Some tcpc device-drivers need to explicitly be told to watch for connection
events, otherwise the tcpc will not generate any TCPM_CC_EVENTs and devices
being plugged into the Type-C port will not be noticed.

For dual-role ports tcpm_start_drp_toggling() is used to tell the tcpc to
watch for connection events. Sofar we lack a similar callback to the tcpc
for single-role ports. With some tcpc-s such as the fusb302 this means
no TCPM_CC_EVENTs will be generated when the port is configured as a
single-role port.

This commit renames start_drp_toggling to start_toggling and since the
device-properties are parsed by the tcpm-core, adds a port_type parameter
to the start_toggling callback so that the tcpc_dev driver knows the
port-type and can act accordingly when it starts toggling.

The new start_toggling callback now always gets called if defined, instead
of only being called for DRP ports.

To avoid this causing undesirable functional changes all existing
start_drp_toggling implementations are not only renamed to start_toggling,
but also get a port_type check added and return -EOPNOTSUPP when port_type
is not DRP.

Fixes: ea3b4d55("usb: typec: fusb302: Resolve fixed power role ...")
Cc: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/fusb302.c

@@ -876,13 +876,17 @@ static int tcpm_set_roles(struct tcpc_dev *dev, bool attached,
 	return ret;
 }
 
-static int tcpm_start_drp_toggling(struct tcpc_dev *dev,
-				   enum typec_cc_status cc)
+static int tcpm_start_toggling(struct tcpc_dev *dev,
+			       enum typec_port_type port_type,
+			       enum typec_cc_status cc)
 {
 	struct fusb302_chip *chip = container_of(dev, struct fusb302_chip,
 						 tcpc_dev);
 	int ret = 0;
 
+	if (port_type != TYPEC_PORT_DRP)
+		return -EOPNOTSUPP;
+
 	mutex_lock(&chip->lock);
 	ret = fusb302_set_src_current(chip, cc_src_current[cc]);
 	if (ret < 0) {
@@ -1088,7 +1092,7 @@ static void init_tcpc_dev(struct tcpc_dev *fusb302_tcpc_dev)
 	fusb302_tcpc_dev->set_vbus = tcpm_set_vbus;
 	fusb302_tcpc_dev->set_pd_rx = tcpm_set_pd_rx;
 	fusb302_tcpc_dev->set_roles = tcpm_set_roles;
-	fusb302_tcpc_dev->start_drp_toggling = tcpm_start_drp_toggling;
+	fusb302_tcpc_dev->start_toggling = tcpm_start_toggling;
 	fusb302_tcpc_dev->pd_transmit = tcpm_pd_transmit;
 }
 

drivers/usb/typec/tcpm/tcpci.c

@@ -100,13 +100,17 @@ static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
 	return 0;
 }
 
-static int tcpci_start_drp_toggling(struct tcpc_dev *tcpc,
-				    enum typec_cc_status cc)
+static int tcpci_start_toggling(struct tcpc_dev *tcpc,
+				enum typec_port_type port_type,
+				enum typec_cc_status cc)
 {
 	int ret;
 	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
 	unsigned int reg = TCPC_ROLE_CTRL_DRP;
 
+	if (port_type != TYPEC_PORT_DRP)
+		return -EOPNOTSUPP;
+
 	/* Handle vendor drp toggling */
 	if (tcpci->data->start_drp_toggling) {
 		ret = tcpci->data->start_drp_toggling(tcpci, tcpci->data, cc);
@@ -511,7 +515,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
 	tcpci->tcpc.get_cc = tcpci_get_cc;
 	tcpci->tcpc.set_polarity = tcpci_set_polarity;
 	tcpci->tcpc.set_vconn = tcpci_set_vconn;
-	tcpci->tcpc.start_drp_toggling = tcpci_start_drp_toggling;
+	tcpci->tcpc.start_toggling = tcpci_start_toggling;
 
 	tcpci->tcpc.set_pd_rx = tcpci_set_pd_rx;
 	tcpci->tcpc.set_roles = tcpci_set_roles;

drivers/usb/typec/tcpm/tcpm.c

@@ -31,7 +31,7 @@
 
 #define FOREACH_STATE(S)			\
 	S(INVALID_STATE),			\
-	S(DRP_TOGGLING),			\
+	S(TOGGLING),			\
 	S(SRC_UNATTACHED),			\
 	S(SRC_ATTACH_WAIT),			\
 	S(SRC_ATTACHED),			\
@@ -472,7 +472,7 @@ static void tcpm_log(struct tcpm_port *port, const char *fmt, ...)
 	/* Do not log while disconnected and unattached */
 	if (tcpm_port_is_disconnected(port) &&
 	    (port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED ||
-	     port->state == DRP_TOGGLING))
+	     port->state == TOGGLING))
 		return;
 
 	va_start(args, fmt);
@@ -2540,20 +2540,16 @@ static int tcpm_set_charge(struct tcpm_port *port, bool charge)
 	return 0;
 }
 
-static bool tcpm_start_drp_toggling(struct tcpm_port *port,
-				    enum typec_cc_status cc)
+static bool tcpm_start_toggling(struct tcpm_port *port, enum typec_cc_status cc)
 {
 	int ret;
 
-	if (port->tcpc->start_drp_toggling &&
-	    port->port_type == TYPEC_PORT_DRP) {
-		tcpm_log_force(port, "Start DRP toggling");
-		ret = port->tcpc->start_drp_toggling(port->tcpc, cc);
-		if (!ret)
-			return true;
-	}
+	if (!port->tcpc->start_toggling)
+		return false;
 
-	return false;
+	tcpm_log_force(port, "Start toggling");
+	ret = port->tcpc->start_toggling(port->tcpc, port->port_type, cc);
+	return ret == 0;
 }
 
 static void tcpm_set_cc(struct tcpm_port *port, enum typec_cc_status cc)
@@ -2847,15 +2843,15 @@ static void run_state_machine(struct tcpm_port *port)
 
 	port->enter_state = port->state;
 	switch (port->state) {
-	case DRP_TOGGLING:
+	case TOGGLING:
 		break;
 	/* SRC states */
 	case SRC_UNATTACHED:
 		if (!port->non_pd_role_swap)
 			tcpm_swap_complete(port, -ENOTCONN);
 		tcpm_src_detach(port);
-		if (tcpm_start_drp_toggling(port, tcpm_rp_cc(port))) {
-			tcpm_set_state(port, DRP_TOGGLING, 0);
+		if (tcpm_start_toggling(port, tcpm_rp_cc(port))) {
+			tcpm_set_state(port, TOGGLING, 0);
 			break;
 		}
 		tcpm_set_cc(port, tcpm_rp_cc(port));
@@ -3053,8 +3049,8 @@ static void run_state_machine(struct tcpm_port *port)
 			tcpm_swap_complete(port, -ENOTCONN);
 		tcpm_pps_complete(port, -ENOTCONN);
 		tcpm_snk_detach(port);
-		if (tcpm_start_drp_toggling(port, TYPEC_CC_RD)) {
-			tcpm_set_state(port, DRP_TOGGLING, 0);
+		if (tcpm_start_toggling(port, TYPEC_CC_RD)) {
+			tcpm_set_state(port, TOGGLING, 0);
 			break;
 		}
 		tcpm_set_cc(port, TYPEC_CC_RD);
@@ -3621,7 +3617,7 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
 						       : "connected");
 
 	switch (port->state) {
-	case DRP_TOGGLING:
+	case TOGGLING:
 		if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
 		    tcpm_port_is_source(port))
 			tcpm_set_state(port, SRC_ATTACH_WAIT, 0);

drivers/usb/typec/tcpm/wcove.c

@@ -416,12 +416,16 @@ static int wcove_pd_transmit(struct tcpc_dev *tcpc,
 	return regmap_write(wcove->regmap, USBC_TXCMD, cmd | USBC_TXCMD_START);
 }
 
-static int wcove_start_drp_toggling(struct tcpc_dev *tcpc,
-				    enum typec_cc_status cc)
+static int wcove_start_toggling(struct tcpc_dev *tcpc,
+				enum typec_port_type port_type,
+				enum typec_cc_status cc)
 {
 	struct wcove_typec *wcove = tcpc_to_wcove(tcpc);
 	unsigned int usbc_ctrl;
 
+	if (port_type != TYPEC_PORT_DRP)
+		return -EOPNOTSUPP;
+
 	usbc_ctrl = USBC_CONTROL1_MODE_DRP | USBC_CONTROL1_DRPTOGGLE_RANDOM;
 
 	switch (cc) {
@@ -639,7 +643,7 @@ static int wcove_typec_probe(struct platform_device *pdev)
 	wcove->tcpc.set_polarity = wcove_set_polarity;
 	wcove->tcpc.set_vconn = wcove_set_vconn;
 	wcove->tcpc.set_current_limit = wcove_set_current_limit;
-	wcove->tcpc.start_drp_toggling = wcove_start_drp_toggling;
+	wcove->tcpc.start_toggling = wcove_start_toggling;
 
 	wcove->tcpc.set_pd_rx = wcove_set_pd_rx;
 	wcove->tcpc.set_roles = wcove_set_roles;

include/linux/usb/tcpm.h

@@ -121,10 +121,10 @@ struct tcpc_config {
  *		with partner.
  * @set_pd_rx:	Called to enable or disable reception of PD messages
  * @set_roles:	Called to set power and data roles
- * @start_drp_toggling:
- *		Optional; if supported by hardware, called to start DRP
- *		toggling. DRP toggling is stopped automatically if
- *		a connection is established.
+ * @start_toggling:
+ *		Optional; if supported by hardware, called to start dual-role
+ *		toggling or single-role connection detection. Toggling stops
+ *		automatically if a connection is established.
  * @try_role:	Optional; called to set a preferred role
  * @pd_transmit:Called to transmit PD message
  * @mux:	Pointer to multiplexer data
@@ -147,8 +147,9 @@ struct tcpc_dev {
 	int (*set_pd_rx)(struct tcpc_dev *dev, bool on);
 	int (*set_roles)(struct tcpc_dev *dev, bool attached,
 			 enum typec_role role, enum typec_data_role data);
-	int (*start_drp_toggling)(struct tcpc_dev *dev,
-				  enum typec_cc_status cc);
+	int (*start_toggling)(struct tcpc_dev *dev,
+			      enum typec_port_type port_type,
+			      enum typec_cc_status cc);
 	int (*try_role)(struct tcpc_dev *dev, int role);
 	int (*pd_transmit)(struct tcpc_dev *dev, enum tcpm_transmit_type type,
 			   const struct pd_message *msg);