[PATCH] usb: typec: tcpci: add alert.fault handling

Add minimal handling to clear the ALERT.Fault bit which may be set in
case of an over-current or over-voltage detection. At the moment only
the IRQ clear support is added since the TCPC Spec mentions that the
handling of such events is vendor specific.

Signed-off-by: Marco Felsch <[email protected]>
---
 drivers/usb/typec/tcpm/tcpci.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index a56e31b20c21..d2d5bf7ca618 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -692,7 +692,8 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 
 	reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED |
 		TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS |
-		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS;
+		TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS |
+		TCPC_ALERT_FAULT;
 	if (tcpci->controls_vbus)
 		reg |= TCPC_ALERT_POWER_STATUS;
 	/* Enable VSAFE0V status interrupt when detecting VSAFE0V is supported */
@@ -720,6 +721,19 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
 	irq_ret = status & tcpci->alert_mask;
 
 process_status:
+	/*
+	 * Handle nested fault before clearing the alert status to not
+	 * re-trigger a fault alert immediately again.
+	 */
+	if (status & TCPC_ALERT_FAULT) {
+		unsigned int fault;
+
+		/* TODO: Add a proper over-current and over-voltage handling */
+		ret = regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &fault);
+		if (!ret)
+			regmap_write(tcpci->regmap, TCPC_FAULT_STATUS, fault);
+	}
+
 	/*
 	 * Clear alert status for everything except RX_STATUS, which shouldn't
 	 * be cleared until we have successfully retrieved message.
-- 
2.47.3