gpio: Disambiguate struct gpio_irq_chip.nested

The nested field in struct gpio_irq_chip currently has two meanings. On
one hand it marks an IRQ chip as being nested (as opposed to chained),
while on the other hand it also means that an IRQ chip uses nested
thread handlers.

However, nested IRQ chips can already be identified by the fact that
they don't pass a parent handler (the driver would instead already have
installed a nested handler using request_irq()).

Therefore, the only use for the nested attribute is to inform gpiolib
that an IRQ chip uses nested thread handlers (as opposed to regular,
non-threaded handlers). To clarify its purpose, rename the field to
"threaded".

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/gpio/driver.h

@@ -108,11 +108,11 @@ struct gpio_irq_chip {
 	unsigned int *map;
 
 	/**
-	 * @nested:
+	 * @threaded:
 	 *
-	 * True if set the interrupt handling is nested.
+	 * True if set the interrupt handling uses nested threads.
 	 */
-	bool nested;
+	bool threaded;
 
 	/**
 	 * @need_valid_mask:
@@ -385,7 +385,7 @@ int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 			     unsigned int first_irq,
 			     irq_flow_handler_t handler,
 			     unsigned int type,
-			     bool nested,
+			     bool threaded,
 			     struct lock_class_key *lock_key);
 
 #ifdef CONFIG_LOCKDEP