pinctrl: nsp: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230403-immutable-irqchips-v1-2-503788a7f6e6@linaro.org

Author: Linus Walleij

drivers/pinctrl/bcm/pinctrl-nsp-gpio.c

@@ -60,7 +60,6 @@ struct nsp_gpio {
 	struct device *dev;
 	void __iomem *base;
 	void __iomem *io_ctrl;
-	struct irq_chip irqchip;
 	struct gpio_chip gc;
 	struct pinctrl_dev *pctl;
 	struct pinctrl_desc pctldesc;
@@ -193,6 +192,7 @@ static void nsp_gpio_irq_mask(struct irq_data *d)
 	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_gpio_irq_set_mask(d, false);
 	raw_spin_unlock_irqrestore(&chip->lock, flags);
+	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
 }
 
 static void nsp_gpio_irq_unmask(struct irq_data *d)
@@ -201,6 +201,7 @@ static void nsp_gpio_irq_unmask(struct irq_data *d)
 	struct nsp_gpio *chip = gpiochip_get_data(gc);
 	unsigned long flags;
 
+	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
 	raw_spin_lock_irqsave(&chip->lock, flags);
 	nsp_gpio_irq_set_mask(d, true);
 	raw_spin_unlock_irqrestore(&chip->lock, flags);
@@ -258,6 +259,16 @@ static int nsp_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	return 0;
 }
 
+static const struct irq_chip nsp_gpio_irq_chip = {
+	.name = "gpio-a",
+	.irq_ack = nsp_gpio_irq_ack,
+	.irq_mask = nsp_gpio_irq_mask,
+	.irq_unmask = nsp_gpio_irq_unmask,
+	.irq_set_type = nsp_gpio_irq_set_type,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int nsp_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
 {
 	struct nsp_gpio *chip = gpiochip_get_data(gc);
@@ -650,14 +661,6 @@ static int nsp_gpio_probe(struct platform_device *pdev)
 	irq = platform_get_irq(pdev, 0);
 	if (irq > 0) {
 		struct gpio_irq_chip *girq;
-		struct irq_chip *irqc;
-
-		irqc = &chip->irqchip;
-		irqc->name = "gpio-a";
-		irqc->irq_ack = nsp_gpio_irq_ack;
-		irqc->irq_mask = nsp_gpio_irq_mask;
-		irqc->irq_unmask = nsp_gpio_irq_unmask;
-		irqc->irq_set_type = nsp_gpio_irq_set_type;
 
 		val = readl(chip->base + NSP_CHIP_A_INT_MASK);
 		val = val | NSP_CHIP_A_GPIO_INT_BIT;
@@ -673,7 +676,7 @@ static int nsp_gpio_probe(struct platform_device *pdev)
 		}
 
 		girq = &chip->gc.irq;
-		girq->chip = irqc;
+		gpio_irq_chip_set_chip(girq, &nsp_gpio_irq_chip);
 		/* This will let us handle the parent IRQ in the driver */
 		girq->parent_handler = NULL;
 		girq->num_parents = 0;