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>

4 files changed, 120 insertions, 11 deletions

diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
index 72a06c0ab1db..1486497a24c1 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
@@ -4,16 +4,33 @@ Specifying interrupt information for devices
 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
 -----------------------------
diff --git a/arch/arm/boot/dts/testcases/tests-interrupts.dtsi b/arch/arm/boot/dts/testcases/tests-interrupts.dtsi
index 6ecda716e9d4..560d6bf680b6 100644
--- a/arch/arm/boot/dts/testcases/tests-interrupts.dtsi
+++ b/arch/arm/boot/dts/testcases/tests-interrupts.dtsi
@@ -27,6 +27,12 @@
                                                 <4 &test_intc2 15 16>;
                         };
 
+                        test_intmap1: intmap1 {
+                                #interrupt-cells = <2>;
+                                #address-cells = <0>;
+                                interrupt-map = <1 2 &test_intc0 15>;
+                        };
+
                         interrupts0 {
                                 interrupt-parent = <&test_intc0>;
                                 interrupts = <1>, <2>, <3>, <4>;
@@ -36,6 +42,16 @@
                                 interrupt-parent = <&test_intmap0>;
                                 interrupts = <1>, <2>, <3>, <4>;
                         };
+
+                        interrupts-extended0 {
+                                interrupts-extended = <&test_intc0 1>,
+                                                      <&test_intc1 2 3 4>,
+                                                      <&test_intc2 5 6>,
+                                                      <&test_intmap0 1>,
+                                                      <&test_intmap0 2>,
+                                                      <&test_intmap0 3>,
+                                                      <&test_intmap1 1 2>;
+                        };
                 };
         };
 };
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 7c4ff122785f..8cc62b4a7988 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -292,17 +292,23 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
         if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
                 return of_irq_parse_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)
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 9c80f0b7556b..e21012bde639 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -231,6 +231,75 @@ static void __init of_selftest_parse_interrupts(void)
         of_node_put(np);
 }
 
+static void __init of_selftest_parse_interrupts_extended(void)
+{
+        struct device_node *np;
+        struct of_phandle_args args;
+        int i, rc;
+
+        np = of_find_node_by_path("/testcase-data/interrupts/interrupts-extended0");
+        if (!np) {
+                pr_err("missing testcase data\n");
+                return;
+        }
+
+        for (i = 0; i < 7; i++) {
+                bool passed = true;
+                rc = of_irq_parse_one(np, i, &args);
+
+                /* Test the values from tests-phandle.dtsi */
+                switch (i) {
+                case 0:
+                        passed &= !rc;
+                        passed &= (args.args_count == 1);
+                        passed &= (args.args[0] == 1);
+                        break;
+                case 1:
+                        passed &= !rc;
+                        passed &= (args.args_count == 3);
+                        passed &= (args.args[0] == 2);
+                        passed &= (args.args[1] == 3);
+                        passed &= (args.args[2] == 4);
+                        break;
+                case 2:
+                        passed &= !rc;
+                        passed &= (args.args_count == 2);
+                        passed &= (args.args[0] == 5);
+                        passed &= (args.args[1] == 6);
+                        break;
+                case 3:
+                        passed &= !rc;
+                        passed &= (args.args_count == 1);
+                        passed &= (args.args[0] == 9);
+                        break;
+                case 4:
+                        passed &= !rc;
+                        passed &= (args.args_count == 3);
+                        passed &= (args.args[0] == 10);
+                        passed &= (args.args[1] == 11);
+                        passed &= (args.args[2] == 12);
+                        break;
+                case 5:
+                        passed &= !rc;
+                        passed &= (args.args_count == 2);
+                        passed &= (args.args[0] == 13);
+                        passed &= (args.args[1] == 14);
+                        break;
+                case 6:
+                        passed &= !rc;
+                        passed &= (args.args_count == 1);
+                        passed &= (args.args[0] == 15);
+                        break;
+                default:
+                        passed = false;
+                }
+
+                selftest(passed, "index %i - data error on node %s rc=%i\n",
+                         i, args.np->full_name, rc);
+        }
+        of_node_put(np);
+}
+
 static int __init of_selftest(void)
 {
         struct device_node *np;
@@ -246,6 +315,7 @@ static int __init of_selftest(void)
         of_selftest_parse_phandle_with_args();
         of_selftest_property_match_string();
         of_selftest_parse_interrupts();
+        of_selftest_parse_interrupts_extended();
         pr_info("end of selftest - %i passed, %i failed\n",
                 selftest_results.passed, selftest_results.failed);
         return 0;