gpio: zx: Pass irqchip when adding gpiochip

We need to convert all old gpio irqchips to pass the irqchip
setup along when adding the gpio_chip. For more info see
drivers/gpio/TODO.

For chained irqchips this is a pretty straight-forward
conversion.

Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Jun Nie <jun.nie@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190809133845.30991-1-linus.walleij@linaro.org

drivers/gpio/gpio-zx.c

@@ -215,6 +215,7 @@ static int zx_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct zx_gpio *chip;
+	struct gpio_irq_chip *girq;
 	int irq, id, ret;
 
 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
@@ -242,31 +243,30 @@ static int zx_gpio_probe(struct platform_device *pdev)
 	chip->gc.parent = dev;
 	chip->gc.owner = THIS_MODULE;
 
-	ret = gpiochip_add_data(&chip->gc, chip);
-	if (ret)
-		return ret;
-
 	/*
 	 * irq_chip support
 	 */
 	writew_relaxed(0xffff, chip->base + ZX_GPIO_IM);
 	writew_relaxed(0, chip->base + ZX_GPIO_IE);
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		gpiochip_remove(&chip->gc);
-		return -ENODEV;
-	}
+	if (irq < 0)
+		return irq;
+	girq = &chip->gc.irq;
+	girq->chip = &zx_irqchip;
+	girq->parent_handler = zx_irq_handler;
+	girq->num_parents = 1;
+	girq->parents = devm_kcalloc(&pdev->dev, 1,
+				     sizeof(*girq->parents),
+				     GFP_KERNEL);
+	if (!girq->parents)
+		return -ENOMEM;
+	girq->parents[0] = irq;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_simple_irq;
 
-	ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip,
-				   0, handle_simple_irq,
-				   IRQ_TYPE_NONE);
-	if (ret) {
-		dev_err(dev, "could not add irqchip\n");
-		gpiochip_remove(&chip->gc);
+	ret = gpiochip_add_data(&chip->gc, chip);
+	if (ret)
 		return ret;
-	}
-	gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip,
-				     irq, zx_irq_handler);
 
 	platform_set_drvdata(pdev, chip);
 	dev_info(dev, "ZX GPIO chip registered\n");