usb: typec: tcpci: Implement callback for apply_rc

APPLY RC is defined as ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and
POWER_CONTROL.AutodischargeDisconnect is 0. When ROLE_CONTROL.CC1 ==
ROLE_CONTROL.CC2, set the other CC to OPEN.

Fixes: f321a02c ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20210517192112.40934-4-badhri@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/tcpci.c

@@ -115,6 +115,32 @@ static int tcpci_set_cc(struct tcpc_dev *tcpc, enum typec_cc_status cc)
 	return 0;
 }
 
+int tcpci_apply_rc(struct tcpc_dev *tcpc, enum typec_cc_status cc, enum typec_cc_polarity polarity)
+{
+	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
+	unsigned int reg;
+	int ret;
+
+	ret = regmap_read(tcpci->regmap, TCPC_ROLE_CTRL, &reg);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * APPLY_RC state is when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and vbus autodischarge on
+	 * disconnect is disabled. Bail out when ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2.
+	 */
+	if (((reg & (TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT)) >>
+	     TCPC_ROLE_CTRL_CC2_SHIFT) !=
+	    ((reg & (TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT)) >>
+	     TCPC_ROLE_CTRL_CC1_SHIFT))
+		return 0;
+
+	return regmap_update_bits(tcpci->regmap, TCPC_ROLE_CTRL, polarity == TYPEC_POLARITY_CC1 ?
+				  TCPC_ROLE_CTRL_CC2_MASK << TCPC_ROLE_CTRL_CC2_SHIFT :
+				  TCPC_ROLE_CTRL_CC1_MASK << TCPC_ROLE_CTRL_CC1_SHIFT,
+				  TCPC_ROLE_CTRL_CC_OPEN);
+}
+
 static int tcpci_start_toggling(struct tcpc_dev *tcpc,
 				enum typec_port_type port_type,
 				enum typec_cc_status cc)
@@ -728,6 +754,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
 	tcpci->tcpc.get_vbus = tcpci_get_vbus;
 	tcpci->tcpc.set_vbus = tcpci_set_vbus;
 	tcpci->tcpc.set_cc = tcpci_set_cc;
+	tcpci->tcpc.apply_rc = tcpci_apply_rc;
 	tcpci->tcpc.get_cc = tcpci_get_cc;
 	tcpci->tcpc.set_polarity = tcpci_set_polarity;
 	tcpci->tcpc.set_vconn = tcpci_set_vconn;