HID: cp2112: 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>
Link: https://lore.kernel.org/r/20230703185222.50554-4-andriy.shevchenko@linux.intel.comSigned-off-by: Benjamin Tissoires <bentiss@kernel.org>

drivers/hid/hid-cp2112.c

@@ -164,7 +164,6 @@ struct cp2112_device {
 	atomic_t read_avail;
 	atomic_t xfer_avail;
 	struct gpio_chip gc;
-	struct irq_chip irq;
 	u8 *in_out_buffer;
 	struct mutex lock;
 
@@ -1079,16 +1078,20 @@ static void cp2112_gpio_irq_mask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
 
-	__clear_bit(d->hwirq, &dev->irq_mask);
+	__clear_bit(hwirq, &dev->irq_mask);
+	gpiochip_disable_irq(gc, hwirq);
 }
 
 static void cp2112_gpio_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
 
-	__set_bit(d->hwirq, &dev->irq_mask);
+	gpiochip_enable_irq(gc, hwirq);
+	__set_bit(hwirq, &dev->irq_mask);
 }
 
 static void cp2112_gpio_poll_callback(struct work_struct *work)
@@ -1174,6 +1177,7 @@ static void cp2112_gpio_irq_shutdown(struct irq_data *d)
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct cp2112_device *dev = gpiochip_get_data(gc);
 
+	cp2112_gpio_irq_mask(d);
 	cancel_delayed_work_sync(&dev->gpio_poll_worker);
 }
 
@@ -1227,6 +1231,18 @@ static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
 	return ret;
 }
 
+static const struct irq_chip cp2112_gpio_irqchip = {
+	.name = "cp2112-gpio",
+	.irq_startup = cp2112_gpio_irq_startup,
+	.irq_shutdown = cp2112_gpio_irq_shutdown,
+	.irq_ack = cp2112_gpio_irq_ack,
+	.irq_mask = cp2112_gpio_irq_mask,
+	.irq_unmask = cp2112_gpio_irq_unmask,
+	.irq_set_type = cp2112_gpio_irq_type,
+	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
 	struct cp2112_device *dev;
@@ -1336,17 +1352,8 @@ static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	dev->gc.can_sleep		= 1;
 	dev->gc.parent			= &hdev->dev;
 
-	dev->irq.name = "cp2112-gpio";
-	dev->irq.irq_startup = cp2112_gpio_irq_startup;
-	dev->irq.irq_shutdown = cp2112_gpio_irq_shutdown;
-	dev->irq.irq_ack = cp2112_gpio_irq_ack;
-	dev->irq.irq_mask = cp2112_gpio_irq_mask;
-	dev->irq.irq_unmask = cp2112_gpio_irq_unmask;
-	dev->irq.irq_set_type = cp2112_gpio_irq_type;
-	dev->irq.flags = IRQCHIP_MASK_ON_SUSPEND;
-
 	girq = &dev->gc.irq;
-	girq->chip = &dev->irq;
+	gpio_irq_chip_set_chip(girq, &cp2112_gpio_irqchip);
 	/* The event comes from the outside so no parent handler */
 	girq->parent_handler = NULL;
 	girq->num_parents = 0;