pinctrl: qcom spmi-mpp: Convert to immutable irq_chip

Convert the driver to immutable irq-chip with a bit of
intuition.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230414-immutable-irqchips-2-v1-4-6b59a5186b00@linaro.org

drivers/pinctrl/qcom/pinctrl-spmi-mpp.c

@@ -143,7 +143,6 @@ struct pmic_mpp_state {
 	struct regmap	*map;
 	struct pinctrl_dev *ctrl;
 	struct gpio_chip chip;
-	struct irq_chip irq;
 };
 
 static const struct pinconf_generic_params pmic_mpp_bindings[] = {
@@ -823,6 +822,33 @@ static int pmic_mpp_child_to_parent_hwirq(struct gpio_chip *chip,
 	return 0;
 }
 
+static void pmic_mpp_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	irq_chip_mask_parent(d);
+	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
+}
+
+static void pmic_mpp_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
+	irq_chip_unmask_parent(d);
+}
+
+static const struct irq_chip pmic_mpp_irq_chip = {
+	.name = "spmi-mpp",
+	.irq_ack = irq_chip_ack_parent,
+	.irq_mask = pmic_mpp_irq_mask,
+	.irq_unmask = pmic_mpp_irq_unmask,
+	.irq_set_type = irq_chip_set_type_parent,
+	.irq_set_wake = irq_chip_set_wake_parent,
+	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int pmic_mpp_probe(struct platform_device *pdev)
 {
 	struct irq_domain *parent_domain;
@@ -915,16 +941,8 @@ static int pmic_mpp_probe(struct platform_device *pdev)
 	if (!parent_domain)
 		return -ENXIO;
 
-	state->irq.name = "spmi-mpp",
-	state->irq.irq_ack = irq_chip_ack_parent,
-	state->irq.irq_mask = irq_chip_mask_parent,
-	state->irq.irq_unmask = irq_chip_unmask_parent,
-	state->irq.irq_set_type = irq_chip_set_type_parent,
-	state->irq.irq_set_wake = irq_chip_set_wake_parent,
-	state->irq.flags = IRQCHIP_MASK_ON_SUSPEND,
-
 	girq = &state->chip.irq;
-	girq->chip = &state->irq;
+	gpio_irq_chip_set_chip(girq, &pmic_mpp_irq_chip);
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_level_irq;
 	girq->fwnode = dev_fwnode(state->dev);