rtc: ftrtc010: Use platform_get_irq() to get the interrupt

[ Upstream commit 05020a7 ]

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 <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211220011524.17206-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/rtc/rtc-ftrtc010.c

@@ -141,11 +141,9 @@ static int ftrtc010_rtc_probe(struct platform_device *pdev)
 		}
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!res)
-		return -ENODEV;
-
-	rtc->rtc_irq = res->start;
+	rtc->rtc_irq = platform_get_irq(pdev, 0);
+	if (rtc->rtc_irq < 0)
+		return rtc->rtc_irq;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)