usb: isp1760: 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 bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq(). Also use irq_get_trigger_type to get the
IRQ trigger flags.
Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211220010411.12075-5-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/isp1760/isp1760-if.c

@@ -13,6 +13,7 @@
 
 #include <linux/usb.h>
 #include <linux/io.h>
+#include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
@@ -191,17 +192,15 @@ static int isp1760_plat_probe(struct platform_device *pdev)
 	unsigned long irqflags;
 	unsigned int devflags = 0;
 	struct resource *mem_res;
-	struct resource *irq_res;
+	int irq;
 	int ret;
 
 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
-	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq_res) {
-		pr_warn("isp1760: IRQ resource not available\n");
-		return -ENODEV;
-	}
-	irqflags = irq_res->flags & IRQF_TRIGGER_MASK;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	irqflags = irq_get_trigger_type(irq);
 
 	if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
 		struct device_node *dp = pdev->dev.of_node;
@@ -239,8 +238,7 @@ static int isp1760_plat_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
-	ret = isp1760_register(mem_res, irq_res->start, irqflags, &pdev->dev,
-			       devflags);
+	ret = isp1760_register(mem_res, irq, irqflags, &pdev->dev, devflags);
 	if (ret < 0)
 		return ret;