serial: altera_jtaguart: 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/20211224142917.6966-7-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index 23c4e0e796944eca07e31ad002f349445cd57b0c..37bffe406b18ea9ece7f10d0e1f609a7d8e85c16 100644 (file)
--- 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