watchdog: s3c2410: Use platform_get_irq() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypassed the hierarchical setup and messed up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211216214747.10454-1-prabhakar.mahadev-lad.rj@bp.renesas.com
[groeck: Fixed context conflicts]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/s3c2410_wdt.c

@@ -661,8 +661,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct s3c2410_wdt *wdt;
-	struct resource *wdt_irq;
 	unsigned int wtcon;
+	int wdt_irq;
 	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -686,11 +686,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 		}
 	}
 
-	wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (wdt_irq == NULL) {
-		dev_err(dev, "no irq resource specified\n");
-		return -ENOENT;
-	}
+	wdt_irq = platform_get_irq(pdev, 0);
+	if (wdt_irq < 0)
+		return wdt_irq;
 
 	/* get the memory region for the watchdog timer */
 	wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
@@ -754,8 +752,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
 		}
 	}
 
-	ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
-				pdev->name, pdev);
+	ret = devm_request_irq(dev, wdt_irq, s3c2410wdt_irq, 0,
+			       pdev->name, pdev);
 	if (ret != 0) {
 		dev_err(dev, "failed to install irq (%d)\n", ret);
 		goto err_cpufreq;