gpio: Use unsigned int for interrupt numbers

Interrupt numbers are never negative, zero serves as the special invalid
value.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.c

@@ -1522,7 +1522,7 @@ static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
  */
 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
 					  struct irq_chip *irqchip,
-					  int parent_irq,
+					  unsigned int parent_irq,
 					  irq_flow_handler_t parent_handler)
 {
 	unsigned int offset;
@@ -1571,7 +1571,7 @@ static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
  */
 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 				  struct irq_chip *irqchip,
-				  int parent_irq,
+				  unsigned int parent_irq,
 				  irq_flow_handler_t parent_handler)
 {
 	gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
@@ -1588,7 +1588,7 @@ EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
  */
 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
 				 struct irq_chip *irqchip,
-				 int parent_irq)
+				 unsigned int parent_irq)
 {
 	if (!gpiochip->irq_nested) {
 		chip_err(gpiochip, "tried to nest a chained gpiochip\n");

include/linux/gpio/driver.h

@@ -168,7 +168,7 @@ struct gpio_chip {
 	unsigned int		irq_base;
 	irq_flow_handler_t	irq_handler;
 	unsigned int		irq_default_type;
-	int			irq_chained_parent;
+	unsigned int		irq_chained_parent;
 	bool			irq_nested;
 	bool			irq_need_valid_mask;
 	unsigned long		*irq_valid_mask;
@@ -244,12 +244,12 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
 
 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
 		struct irq_chip *irqchip,
-		int parent_irq,
+		unsigned int parent_irq,
 		irq_flow_handler_t parent_handler);
 
 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
 		struct irq_chip *irqchip,
-		int parent_irq);
+		unsigned int parent_irq);
 
 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 			     struct irq_chip *irqchip,