[PATCH 06/10] serial: altera_jtaguart: Use platform_get_irq_optional() to get the interrupt

[Lad Prabhakar]

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_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
 drivers/tty/serial/altera_jtaguart.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index 23c4e0e79694..37bffe406b18 100644
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -418,8 +418,9 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
 	struct altera_jtaguart_platform_uart *platp =
 			dev_get_platdata(&pdev->dev);
 	struct uart_port *port;
-	struct resource *res_irq, *res_mem;
+	struct resource *res_mem;
 	int i = pdev->id;
+	int irq;
 
 	/* -1 emphasizes that the platform must have one port, no .N suffix */
 	if (i == -1)
@@ -438,9 +439,11 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
 	else
 		return -ENODEV;
 
-	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (res_irq)
-		port->irq = res_irq->start;
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
+		return irq;
+	if (irq > 0)
+		port->irq = irq;
 	else if (platp)
 		port->irq = platp->irq;
 	else
-- 
2.17.1