gpio: dln2: make irq_chip immutable

Since recently, the kernel is nagging about mutable irq_chips:

   "not an immutable chip, please consider fixing it!"

Drop the unneeded copy, flag it as IRQCHIP_IMMUTABLE, add the new
helper functions and call the appropriate gpiolib functions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Author: andy-shev

drivers/gpio/gpio-dln2.c

@@ -46,7 +46,6 @@
 struct dln2_gpio {
 	struct platform_device *pdev;
 	struct gpio_chip gpio;
-	struct irq_chip irqchip;
 
 	/*
 	 * Cache pin direction to save us one transfer, since the hardware has
@@ -306,6 +305,7 @@ static void dln2_irq_unmask(struct irq_data *irqd)
 	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
 	int pin = irqd_to_hwirq(irqd);
 
+	gpiochip_enable_irq(gc, pin);
 	set_bit(pin, dln2->unmasked_irqs);
 }
 
@@ -316,6 +316,7 @@ static void dln2_irq_mask(struct irq_data *irqd)
 	int pin = irqd_to_hwirq(irqd);
 
 	clear_bit(pin, dln2->unmasked_irqs);
+	gpiochip_disable_irq(gc, pin);
 }
 
 static int dln2_irq_set_type(struct irq_data *irqd, unsigned type)
@@ -384,6 +385,17 @@ static void dln2_irq_bus_unlock(struct irq_data *irqd)
 	mutex_unlock(&dln2->irq_lock);
 }
 
+static const struct irq_chip dln2_irqchip = {
+	.name = "dln2-irq",
+	.irq_mask = dln2_irq_mask,
+	.irq_unmask = dln2_irq_unmask,
+	.irq_set_type = dln2_irq_set_type,
+	.irq_bus_lock = dln2_irq_bus_lock,
+	.irq_bus_sync_unlock = dln2_irq_bus_unlock,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
 			    const void *data, int len)
 {
@@ -465,15 +477,8 @@ static int dln2_gpio_probe(struct platform_device *pdev)
 	dln2->gpio.direction_output = dln2_gpio_direction_output;
 	dln2->gpio.set_config = dln2_gpio_set_config;
 
-	dln2->irqchip.name = "dln2-irq",
-	dln2->irqchip.irq_mask = dln2_irq_mask,
-	dln2->irqchip.irq_unmask = dln2_irq_unmask,
-	dln2->irqchip.irq_set_type = dln2_irq_set_type,
-	dln2->irqchip.irq_bus_lock = dln2_irq_bus_lock,
-	dln2->irqchip.irq_bus_sync_unlock = dln2_irq_bus_unlock,
-
 	girq = &dln2->gpio.irq;
-	girq->chip = &dln2->irqchip;
+	gpio_irq_chip_set_chip(girq, &dln2_irqchip);
 	/* The event comes from the outside so no parent handler */
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;