openwrt/target/linux/mvebu/patches-3.10/0176-of-irq-create-interrupts-extended-property.patch

From 6dc29d94d92ccc558b946bd57cd8d7cb19d8def1 Mon Sep 17 00:00:00 2001
From: Grant Likely <grant.likely@linaro.org>
Date: Thu, 19 Dec 2013 09:30:47 -0300
Subject: [PATCH 176/203] of/irq: create interrupts-extended property

The standard interrupts property in device tree can only handle
interrupts coming from a single interrupt parent. If a device is wired
to multiple interrupt controllers, then it needs to be attached to a
node with an interrupt-map property to demux the interrupt specifiers
which is confusing. It would be a lot easier if there was a form of the
interrupts property that allows for a separate interrupt phandle for
each interrupt specifier.

This patch does exactly that by creating a new interrupts-extended
property which reuses the phandle+arguments pattern used by GPIOs and
other core bindings.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kumar Gala <galak@codeaurora.org>
[grant.likely: removed versatile platform hunks into separate patch]
Cc: Rob Herring <rob.herring@calxeda.com>

Conflicts:
	arch/arm/boot/dts/testcases/tests-interrupts.dtsi
	drivers/of/selftest.c
---
 .../bindings/interrupt-controller/interrupts.txt   | 29 +++++++++++++++++-----
 drivers/of/irq.c                                   | 16 ++++++++----
 2 files changed, 34 insertions(+), 11 deletions(-)

--- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
@@ -4,16 +4,33 @@ Specifying interrupt information for dev
 1) Interrupt client nodes
 -------------------------
 
-Nodes that describe devices which generate interrupts must contain an
-"interrupts" property. This property must contain a list of interrupt
-specifiers, one per output interrupt. The format of the interrupt specifier is
-determined by the interrupt controller to which the interrupts are routed; see
-section 2 below for details.
+Nodes that describe devices which generate interrupts must contain an either an
+"interrupts" property or an "interrupts-extended" property. These properties
+contain a list of interrupt specifiers, one per output interrupt. The format of
+the interrupt specifier is determined by the interrupt controller to which the
+interrupts are routed; see section 2 below for details.
+
+  Example:
+	interrupt-parent = <&intc1>;
+	interrupts = <5 0>, <6 0>;
 
 The "interrupt-parent" property is used to specify the controller to which
 interrupts are routed and contains a single phandle referring to the interrupt
 controller node. This property is inherited, so it may be specified in an
-interrupt client node or in any of its parent nodes.
+interrupt client node or in any of its parent nodes. Interrupts listed in the
+"interrupts" property are always in reference to the node's interrupt parent.
+
+The "interrupts-extended" property is a special form for use when a node needs
+to reference multiple interrupt parents. Each entry in this property contains
+both the parent phandle and the interrupt specifier. "interrupts-extended"
+should only be used when a device has multiple interrupt parents.
+
+  Example:
+	interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
+
+A device node may contain either "interrupts" or "interrupts-extended", but not
+both. If both properties are present, then the operating system should log an
+error and use only the data in "interrupts".
 
 2) Interrupt controller nodes
 -----------------------------
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -293,17 +293,23 @@ int of_irq_map_one(struct device_node *d
 	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
 		return of_irq_map_oldworld(device, index, out_irq);
 
+	/* Get the reg property (if any) */
+	addr = of_get_property(device, "reg", NULL);
+
 	/* Get the interrupts property */
 	intspec = of_get_property(device, "interrupts", &intlen);
-	if (intspec == NULL)
-		return -EINVAL;
+	if (intspec == NULL) {
+		/* Try the new-style interrupts-extended */
+		res = of_parse_phandle_with_args(device, "interrupts-extended",
+						"#interrupt-cells", index, out_irq);
+		if (res)
+			return -EINVAL;
+		return of_irq_parse_raw(addr, out_irq);
+	}
 	intlen /= sizeof(*intspec);
 
 	pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
 
-	/* Get the reg property (if any) */
-	addr = of_get_property(device, "reg", NULL);
-
 	/* Look for the interrupt parent. */
 	p = of_irq_find_parent(device);
 	if (p == NULL)