usb: typec: tcpci: Request IRQ with IRQF_SHARED

Under resource constraints, this interrupt may use other interrupt line
or this interrupt line may be shared with other devices as long as they
meet the sharing requirements. Besides, This irq flag will not cause other
side effect if tcpci driver is the only user.
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20221214022334.2520677-1-xu.yang_2@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/tcpci.c

@@ -33,6 +33,7 @@ struct tcpci {
 	struct tcpm_port *port;
 
 	struct regmap *regmap;
+	unsigned int alert_mask;
 
 	bool controls_vbus;
 
@@ -632,6 +633,9 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 		if (ret < 0)
 			return ret;
 	}
+
+	tcpci->alert_mask = reg;
+
 	return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg);
 }
 
@@ -715,7 +719,7 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
 	else if (status & TCPC_ALERT_TX_FAILED)
 		tcpm_pd_transmit_complete(tcpci->port, TCPC_TX_FAILED);
 
-	return IRQ_HANDLED;
+	return IRQ_RETVAL(status & tcpci->alert_mask);
 }
 EXPORT_SYMBOL_GPL(tcpci_irq);
 
@@ -838,7 +842,7 @@ static int tcpci_probe(struct i2c_client *client)
 
 	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 					_tcpci_irq,
-					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+					IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
 					dev_name(&client->dev), chip);
 	if (err < 0) {
 		tcpci_unregister_port(chip->tcpci);