gpio: aspeed: Convert to immutable irq_chip

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

Cc: Marc Zyngier <maz@kernel.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-aspeed.c

@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 
@@ -53,7 +54,7 @@ struct aspeed_gpio_config {
  */
 struct aspeed_gpio {
 	struct gpio_chip chip;
-	struct irq_chip irqc;
+	struct device *dev;
 	raw_spinlock_t lock;
 	void __iomem *base;
 	int irq;
@@ -566,6 +567,10 @@ static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
 
 	addr = bank_reg(gpio, bank, reg_irq_enable);
 
+	/* Unmasking the IRQ */
+	if (set)
+		gpiochip_enable_irq(&gpio->chip, irqd_to_hwirq(d));
+
 	raw_spin_lock_irqsave(&gpio->lock, flags);
 	copro = aspeed_gpio_copro_request(gpio, offset);
 
@@ -579,6 +584,10 @@ static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set)
 	if (copro)
 		aspeed_gpio_copro_release(gpio, offset);
 	raw_spin_unlock_irqrestore(&gpio->lock, flags);
+
+	/* Masking the IRQ */
+	if (!set)
+		gpiochip_disable_irq(&gpio->chip, irqd_to_hwirq(d));
 }
 
 static void aspeed_gpio_irq_mask(struct irq_data *d)
@@ -1080,6 +1089,30 @@ int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc)
 }
 EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio);
 
+static void aspeed_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	const struct aspeed_gpio_bank *bank;
+	struct aspeed_gpio *gpio;
+	u32 bit;
+	int rc, offset;
+
+	rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset);
+	if (rc)
+		return;
+
+	seq_printf(p, dev_name(gpio->dev));
+}
+
+static const struct irq_chip aspeed_gpio_irq_chip = {
+	.irq_ack = aspeed_gpio_irq_ack,
+	.irq_mask = aspeed_gpio_irq_mask,
+	.irq_unmask = aspeed_gpio_irq_unmask,
+	.irq_set_type = aspeed_gpio_set_type,
+	.irq_print_chip = aspeed_gpio_irq_print_chip,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 /*
  * Any banks not specified in a struct aspeed_bank_props array are assumed to
  * have the properties:
@@ -1150,6 +1183,8 @@ static int __init aspeed_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(gpio->base))
 		return PTR_ERR(gpio->base);
 
+	gpio->dev = &pdev->dev;
+
 	raw_spin_lock_init(&gpio->lock);
 
 	gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node);
@@ -1208,12 +1243,8 @@ static int __init aspeed_gpio_probe(struct platform_device *pdev)
 		return irq;
 	gpio->irq = irq;
 	girq = &gpio->chip.irq;
-	girq->chip = &gpio->irqc;
-	girq->chip->name = dev_name(&pdev->dev);
-	girq->chip->irq_ack = aspeed_gpio_irq_ack;
-	girq->chip->irq_mask = aspeed_gpio_irq_mask;
-	girq->chip->irq_unmask = aspeed_gpio_irq_unmask;
-	girq->chip->irq_set_type = aspeed_gpio_set_type;
+	gpio_irq_chip_set_chip(girq, &aspeed_gpio_irq_chip);
+
 	girq->parent_handler = aspeed_gpio_irq_handler;
 	girq->num_parents = 1;
 	girq->parents = devm_kcalloc(&pdev->dev, 1, sizeof(*girq->parents), GFP_KERNEL);