ARM: shmobile: irqpin: add a DT property to enable masking on parent

To disable spurious interrupts, that get triggered on certain hardware, the
irqpin driver masks them on the parent interrupt controller. To specify
such broken devices a .control_parent parameter can be provided in the
platform data. In the DT case we need a property, to do the same.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt

@@ -12,3 +12,5 @@ Optional properties:
   properties
 - sense-bitfield-width: width of a single sense bitfield in the SENSE register,
   if different from the default 4 bits
+- control-parent: disable and enable interrupts on the parent interrupt
+  controller, needed for some broken implementations

drivers/irqchip/irq-renesas-intc-irqpin.c

@@ -348,11 +348,14 @@ static int intc_irqpin_probe(struct platform_device *pdev)
 	}
 
 	/* deal with driver instance configuration */
-	if (pdata)
+	if (pdata) {
 		memcpy(&p->config, pdata, sizeof(*pdata));
-	else
+	} else {
 		of_property_read_u32(pdev->dev.of_node, "sense-bitfield-width",
 				     &p->config.sense_bitfield_width);
+		p->config.control_parent = of_property_read_bool(pdev->dev.of_node,
+								 "control-parent");
+	}
 	if (!p->config.sense_bitfield_width)
 		p->config.sense_bitfield_width = 4; /* default to 4 bits */