serial: altera: Use platform_get_irq_optional() 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_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224142917.6966-2-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 7c5f4e966b594b42ac02671470fa5f21bec1130c..64a352b40197101577089053feeadf3d24e2a767 100644 (file)
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -553,7 +553,6 @@ static int altera_uart_probe(struct platform_device *pdev)
        struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
        struct uart_port *port;
        struct resource *res_mem;
-       struct resource *res_irq;
        int i = pdev->id;
        int ret;
 
@@ -577,9 +576,11 @@ static int altera_uart_probe(struct platform_device *pdev)
        else
                return -EINVAL;
 
-       res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-       if (res_irq)
-               port->irq = res_irq->start;
+       ret = platform_get_irq_optional(pdev, 0);
+       if (ret < 0 && ret != -ENXIO)
+               return ret;
+       if (ret > 0)
+               port->irq = ret;
        else if (platp)
                port->irq = platp->irq;