gpio: xgs-iproc: 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>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: Linus Walleij

drivers/gpio/gpio-xgs-iproc.c

@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 
 #define IPROC_CCA_INT_F_GPIOINT		BIT(0)
@@ -27,7 +28,6 @@
 #define IPROC_GPIO_CCA_INT_EDGE		0x24
 
 struct iproc_gpio_chip {
-	struct irq_chip irqchip;
 	struct gpio_chip gc;
 	spinlock_t lock;
 	struct device *dev;
@@ -69,6 +69,7 @@ static void iproc_gpio_irq_unmask(struct irq_data *d)
 	u32 irq = d->irq;
 	u32 int_mask, irq_type, event_mask;
 
+	gpiochip_enable_irq(gc, pin);
 	spin_lock_irqsave(&chip->lock, flags);
 	irq_type = irq_get_trigger_type(irq);
 	event_mask = readl_relaxed(chip->base + IPROC_GPIO_CCA_INT_EVENT_MASK);
@@ -110,6 +111,7 @@ static void iproc_gpio_irq_mask(struct irq_data *d)
 			       chip->base + IPROC_GPIO_CCA_INT_LEVEL_MASK);
 	}
 	spin_unlock_irqrestore(&chip->lock, flags);
+	gpiochip_disable_irq(gc, pin);
 }
 
 static int iproc_gpio_irq_set_type(struct irq_data *d, u32 type)
@@ -191,6 +193,24 @@ static irqreturn_t iproc_gpio_irq_handler(int irq, void *data)
 	return int_bits ? IRQ_HANDLED : IRQ_NONE;
 }
 
+static void iproc_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+
+	seq_printf(p, dev_name(chip->dev));
+}
+
+static const struct irq_chip iproc_gpio_irq_chip = {
+	.irq_ack = iproc_gpio_irq_ack,
+	.irq_mask = iproc_gpio_irq_mask,
+	.irq_unmask = iproc_gpio_irq_unmask,
+	.irq_set_type = iproc_gpio_irq_set_type,
+	.irq_print_chip = iproc_gpio_irq_print_chip,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int iproc_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -230,16 +250,8 @@ static int iproc_gpio_probe(struct platform_device *pdev)
 	irq = platform_get_irq(pdev, 0);
 	if (irq > 0) {
 		struct gpio_irq_chip *girq;
-		struct irq_chip *irqc;
 		u32 val;
 
-		irqc = &chip->irqchip;
-		irqc->name = dev_name(dev);
-		irqc->irq_ack = iproc_gpio_irq_ack;
-		irqc->irq_mask = iproc_gpio_irq_mask;
-		irqc->irq_unmask = iproc_gpio_irq_unmask;
-		irqc->irq_set_type = iproc_gpio_irq_set_type;
-
 		chip->intr = devm_platform_ioremap_resource(pdev, 1);
 		if (IS_ERR(chip->intr))
 			return PTR_ERR(chip->intr);
@@ -261,7 +273,7 @@ static int iproc_gpio_probe(struct platform_device *pdev)
 		}
 
 		girq = &chip->gc.irq;
-		girq->chip = irqc;
+		gpio_irq_chip_set_chip(girq, &iproc_gpio_irq_chip);
 		/* This will let us handle the parent IRQ in the driver */
 		girq->parent_handler = NULL;
 		girq->num_parents = 0;