gpiolib: wrap gpio_chip::set()

We have three places where we dereference the gpio_chip::set() callback.
In order to make it easier to incorporate the upcoming new variant of
this callback (one returning an integer value), wrap it in a helper so
that the dereferencing only happens once.

Reviewed-by: Linus Walleij <[email protected]>
Acked-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bartosz Golaszewski <[email protected]>

Author: Bartosz Golaszewski

drivers/gpio/gpiolib.c

@@ -2825,6 +2825,17 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
 	return ret;
 }
 
+static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	lockdep_assert_held(&gc->gpiodev->srcu);
+
+	if (WARN_ON(unlikely(!gc->set)))
+		return -EOPNOTSUPP;
+
+	gc->set(gc, offset, value);
+	return 0;
+}
+
 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 {
 	int val = !!value, ret = 0;
@@ -2867,7 +2878,9 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
 		 * If we can't actively set the direction, we are some
 		 * output-only chip, so just drive the output as desired.
 		 */
-		guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
+		ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val);
+		if (ret)
+			return ret;
 	}
 
 	if (!ret)
@@ -3557,9 +3570,7 @@ static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
 		return -ENODEV;
 
 	trace_gpio_value(desc_to_gpio(desc), 0, value);
-	guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
-
-	return 0;
+	return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value);
 }
 
 /*
@@ -3584,7 +3595,7 @@ static void gpio_chip_set_multiple(struct gpio_chip *gc,
 
 		/* set outputs if the corresponding mask bit is set */
 		for_each_set_bit(i, mask, gc->ngpio)
-			gc->set(gc, i, test_bit(i, bits));
+			gpiochip_set(gc, i, test_bit(i, bits));
 	}
 }