gpio: dwapb: Use generic request, free and set_config

This way GPIO will be denied on pins already claimed by other devices
and basic pin configuration (pull-up, pull-down etc.) can be done
through the userspace GPIO API.
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -416,11 +416,12 @@ static int dwapb_gpio_set_config(struct gpio_chip *gc, unsigned offset,
 {
 	u32 debounce;
 
-	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
-		return -ENOTSUPP;
-
+	if (pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE) {
 		debounce = pinconf_to_config_argument(config);
 		return dwapb_gpio_set_debounce(gc, offset, debounce);
+	}
+
+	return gpiochip_generic_config(gc, offset, config);
 }
 
 static int dwapb_convert_irqs(struct dwapb_gpio_port_irqchip *pirq,
@@ -530,10 +531,14 @@ static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
 	port->gc.fwnode = pp->fwnode;
 	port->gc.ngpio = pp->ngpio;
 	port->gc.base = pp->gpio_base;
+	port->gc.request = gpiochip_generic_request;
+	port->gc.free = gpiochip_generic_free;
 
 	/* Only port A support debounce */
 	if (pp->idx == 0)
 		port->gc.set_config = dwapb_gpio_set_config;
+	else
+		port->gc.set_config = gpiochip_generic_config;
 
 	/* Only port A can provide interrupts in all configurations of the IP */
 	if (pp->idx == 0)