Revert "gpiolib: Remove duplicated function gpio_do_set_config()"

This reverts commit d18fddff.

This patch came on top of another patch that introduced a regression.
Revert it before addressing the culprit.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>

drivers/gpio/gpiolib.c

@@ -3035,8 +3035,8 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
  * rely on gpio_request() having been called beforehand.
  */
 
-static int gpio_set_config(struct gpio_chip *gc, unsigned int offset,
-			   enum pin_config_param mode)
+static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
+			      enum pin_config_param mode)
 {
 	if (!gc->set_config)
 		return -ENOTSUPP;
@@ -3044,6 +3044,25 @@ static int gpio_set_config(struct gpio_chip *gc, unsigned int offset,
 	return gc->set_config(gc, offset, mode);
 }
 
+static int gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+			   enum pin_config_param mode)
+{
+	unsigned arg;
+
+	switch (mode) {
+	case PIN_CONFIG_BIAS_DISABLE:
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+	case PIN_CONFIG_BIAS_PULL_UP:
+		arg = 1;
+		break;
+
+	default:
+		arg = 0;
+	}
+
+	return gpio_do_set_config(gc, offset, mode);
+}
+
 static int gpio_set_bias(struct gpio_chip *chip, struct gpio_desc *desc)
 {
 	int bias = 0;
@@ -3277,7 +3296,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
 	chip = desc->gdev->chip;
 
 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
-	return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
+	return gpio_do_set_config(chip, gpio_chip_hwgpio(desc), config);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
 
@@ -3311,7 +3330,7 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
 	packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
 					  !transitory);
 	gpio = gpio_chip_hwgpio(desc);
-	rc = gpio_set_config(chip, gpio, packed);
+	rc = gpio_do_set_config(chip, gpio, packed);
 	if (rc == -ENOTSUPP) {
 		dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
 				gpio);