1 files changed, 20 insertions, 3 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index e0f4c3d9649c..94398f89e600 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1841,9 +1841,6 @@ static int ftdi_gpio_request(struct gpio_chip *gc, unsigned int offset)
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
 	int result;
 
-	if (priv->gpio_altfunc & BIT(offset))
-		return -ENODEV;
-
 	mutex_lock(&priv->gpio_lock);
 	if (!priv->gpio_used) {
 		/* Set default pin states, as we cannot get them from device */
@@ -2002,6 +1999,25 @@ static int ftdi_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
 	return result;
 }
 
+static int ftdi_gpio_init_valid_mask(struct gpio_chip *gc,
+				     unsigned long *valid_mask,
+				     unsigned int ngpios)
+{
+	struct usb_serial_port *port = gpiochip_get_data(gc);
+	struct ftdi_private *priv = usb_get_serial_port_data(port);
+	unsigned long map = priv->gpio_altfunc;
+
+	bitmap_complement(valid_mask, &map, ngpios);
+
+	if (bitmap_empty(valid_mask, ngpios))
+		dev_dbg(&port->dev, "no CBUS pin configured for GPIO\n");
+	else
+		dev_dbg(&port->dev, "CBUS%*pbl configured for GPIO\n", ngpios,
+			valid_mask);
+
+	return 0;
+}
+
 static int ftdi_read_eeprom(struct usb_serial *serial, void *dst, u16 addr,
 				u16 nbytes)
 {
@@ -2173,6 +2189,7 @@ static int ftdi_gpio_init(struct usb_serial_port *port)
 	priv->gc.get_direction = ftdi_gpio_direction_get;
 	priv->gc.direction_input = ftdi_gpio_direction_input;
 	priv->gc.direction_output = ftdi_gpio_direction_output;
+	priv->gc.init_valid_mask = ftdi_gpio_init_valid_mask;
 	priv->gc.get = ftdi_gpio_get;
 	priv->gc.set = ftdi_gpio_set;
 	priv->gc.get_multiple = ftdi_gpio_get_multiple;