pinctrl: iproc-gpio: Handle interrupts for multiple instances

When multiple instance of iproc-gpio chips are present, a fix up
message[1] is printed during the probe of second and later instances.

This issue is because driver sharing same irq_chip data structure
among multiple instances of driver.

Fix this by allocating irq_chip data structure per instance of
iproc-gpio.

[1] fix up message addressed by this patch
[  7.862208] gpio gpiochip2: (689d0000.gpio): detected irqchip that
   is shared with multiple gpiochips: please fix the driver.

Fixes: 616043d5 ("pinctrl: Rename gpio driver from cygnus to iproc")
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Link: https://lore.kernel.org/r/1567054348-19685-3-git-send-email-srinath.mannam@broadcom.com
[Rebased on top of new irq chip set-up code]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/pinctrl-iproc-gpio.c

@@ -114,6 +114,7 @@ struct iproc_gpio {
 
 	raw_spinlock_t lock;
 
+	struct irq_chip irqchip;
 	struct gpio_chip gc;
 	unsigned num_banks;
 
@@ -302,14 +303,6 @@ static int iproc_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	return 0;
 }
 
-static struct irq_chip iproc_gpio_irq_chip = {
-	.name = "bcm-iproc-gpio",
-	.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,
-};
-
 /*
  * Request the Iproc IOMUX pinmux controller to mux individual pins to GPIO
  */
@@ -851,10 +844,20 @@ static int iproc_gpio_probe(struct platform_device *pdev)
 	/* optional GPIO interrupt support */
 	irq = platform_get_irq(pdev, 0);
 	if (irq) {
+		struct irq_chip *irqc;
 		struct gpio_irq_chip *girq;
 
+		irqc = &chip->irqchip;
+		irqc->name = "bcm-iproc-gpio";
+		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;
+		irqc->irq_enable = iproc_gpio_irq_unmask;
+		irqc->irq_disable = iproc_gpio_irq_mask;
+
 		girq = &gc->irq;
-		girq->chip = &iproc_gpio_irq_chip;
+		girq->chip = irqc;
 		girq->parent_handler = iproc_gpio_irq_handler;
 		girq->num_parents = 1;
 		girq->parents = devm_kcalloc(dev, 1,