serial: st-asc: Use new GPIOD API to obtain RTS pin

The commits mentioned below adapt the GPIO API to allow more information
to be passed directly through devm_get_gpiod_from_child() in the first
instance.  This facilitates the removal of subsequent calls, such as
gpiod_direction_output().  This patch firstly moves to utilise the new
API and secondly removes the now superfluous call do set the direction.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[Also drop the header file dummies that only this driver was using]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/tty/serial/st-asc.c

@@ -575,14 +575,15 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
 			pinctrl_select_state(ascport->pinctrl,
 					     ascport->states[NO_HW_FLOWCTRL]);
 
-			gpiod =	devm_get_gpiod_from_child(port->dev, "rts",
-							  &np->fwnode);
-			if (!IS_ERR(gpiod)) {
-				gpiod_direction_output(gpiod, 0);
+			gpiod = devm_fwnode_get_gpiod_from_child(port->dev,
+								 "rts",
+								 &np->fwnode,
+								 GPIOD_OUT_LOW,
+								 np->name);
+			if (!IS_ERR(gpiod))
 				ascport->rts = gpiod;
 		}
 	}
-	}
 
 	if ((baud < 19200) && !ascport->force_m1) {
 		asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));

include/linux/gpio/consumer.h

@@ -143,15 +143,6 @@ struct gpio_desc *devm_fwnode_get_index_gpiod_from_child(struct device *dev,
 						struct fwnode_handle *child,
 						enum gpiod_flags flags,
 						const char *label);
-/* FIXME: delete this helper when users are switched over */
-static inline struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
-			  const char *con_id, struct fwnode_handle *child)
-{
-	return devm_fwnode_get_index_gpiod_from_child(dev, con_id,
-						      0, child,
-						      GPIOD_ASIS,
-						      "?");
-}
 
 #else /* CONFIG_GPIOLIB */
 
@@ -444,13 +435,6 @@ struct gpio_desc *devm_fwnode_get_index_gpiod_from_child(struct device *dev,
 	return ERR_PTR(-ENOSYS);
 }
 
-/* FIXME: delete this when all users are switched over */
-static inline struct gpio_desc *devm_get_gpiod_from_child(struct device *dev,
-			  const char *con_id, struct fwnode_handle *child)
-{
-	return ERR_PTR(-ENOSYS);
-}
-
 #endif /* CONFIG_GPIOLIB */
 
 static inline