serial: ar933x: 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().

Signed-off-by: Lad Prabhakar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: prabhakarlad

drivers/tty/serial/ar933x_uart.c

@@ -707,11 +707,11 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	struct ar933x_uart_port *up;
 	struct uart_port *port;
 	struct resource *mem_res;
-	struct resource *irq_res;
 	struct device_node *np;
 	unsigned int baud;
 	int id;
 	int ret;
+	int irq;
 
 	np = pdev->dev.of_node;
 	if (IS_ENABLED(CONFIG_OF) && np) {
@@ -730,11 +730,9 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 	if (id >= CONFIG_SERIAL_AR933X_NR_UARTS)
 		return -EINVAL;
 
-	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq_res) {
-		dev_err(&pdev->dev, "no IRQ resource\n");
-		return -EINVAL;
-	}
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
 			  GFP_KERNEL);
@@ -766,7 +764,7 @@ static int ar933x_uart_probe(struct platform_device *pdev)
 
 	port->mapbase = mem_res->start;
 	port->line = id;
-	port->irq = irq_res->start;
+	port->irq = irq;
 	port->dev = &pdev->dev;
 	port->type = PORT_AR933X;
 	port->iotype = UPIO_MEM32;