[PATCH v2 3/4] usb: typec: tcpci: clear the fault status bit

[Marco Felsch]

According the "USB Type-C Port Controller Interface Specification v2.0"
the TCPC sets the fault status register bit-7
(AllRegistersResetToDefault) once the registers have been reseted to
their default values.

This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
fault-irq. Fix this gernally by writing a one to the correspondig
bit-7.

Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
---
 drivers/usb/typec/tcpm/tcpci.c | 5 +++++
 include/linux/usb/tcpci.h      | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 8da23240afbe..15632d023e4c 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -602,6 +602,11 @@ static int tcpci_init(struct tcpc_dev *tcpc)
 	if (time_after(jiffies, timeout))
 		return -ETIMEDOUT;
 
+	regmap_read(tcpci->regmap, TCPC_FAULT_STATUS, &reg);
+	if (reg & TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT)
+		tcpci_write16(tcpci, TCPC_FAULT_STATUS,
+			      TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+
 	/* Handle vendor init */
 	if (tcpci->data->init) {
 		ret = tcpci->data->init(tcpci, tcpci->data);
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index 85e95a3251d3..83376473ac76 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -103,6 +103,7 @@
 #define TCPC_POWER_STATUS_SINKING_VBUS	BIT(0)
 
 #define TCPC_FAULT_STATUS		0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
 
 #define TCPC_ALERT_EXTENDED		0x21
 

-- 
2.39.2