gpio: sprd: Make the irqchip immutable

Make the struct irq_chip const, flag it as IRQCHIP_IMMUTABLE, add the
new helper functions, and call the appropriate gpiolib functions.
Signed-off-by: Cixi Geng <cixi.geng1@unisoc.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-sprd.c

@@ -120,6 +120,7 @@ static void sprd_gpio_irq_mask(struct irq_data *data)
 	u32 offset = irqd_to_hwirq(data);
 
 	sprd_gpio_update(chip, offset, SPRD_GPIO_IE, 0);
+	gpiochip_disable_irq(chip, offset);
 }
 
 static void sprd_gpio_irq_ack(struct irq_data *data)
@@ -136,6 +137,7 @@ static void sprd_gpio_irq_unmask(struct irq_data *data)
 	u32 offset = irqd_to_hwirq(data);
 
 	sprd_gpio_update(chip, offset, SPRD_GPIO_IE, 1);
+	gpiochip_enable_irq(chip, offset);
 }
 
 static int sprd_gpio_irq_set_type(struct irq_data *data,
@@ -205,13 +207,14 @@ static void sprd_gpio_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(ic, desc);
 }
 
-static struct irq_chip sprd_gpio_irqchip = {
+static const struct irq_chip sprd_gpio_irqchip = {
 	.name = "sprd-gpio",
 	.irq_ack = sprd_gpio_irq_ack,
 	.irq_mask = sprd_gpio_irq_mask,
 	.irq_unmask = sprd_gpio_irq_unmask,
 	.irq_set_type = sprd_gpio_irq_set_type,
-	.flags = IRQCHIP_SKIP_SET_WAKE,
+	.flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
 };
 
 static int sprd_gpio_probe(struct platform_device *pdev)
@@ -245,7 +248,7 @@ static int sprd_gpio_probe(struct platform_device *pdev)
 	sprd_gpio->chip.direction_output = sprd_gpio_direction_output;
 
 	irq = &sprd_gpio->chip.irq;
-	irq->chip = &sprd_gpio_irqchip;
+	gpio_irq_chip_set_chip(irq, &sprd_gpio_irqchip);
 	irq->handler = handle_bad_irq;
 	irq->default_type = IRQ_TYPE_NONE;
 	irq->parent_handler = sprd_gpio_irq_handler;