[PATCH 2/2] gpio/tegra: Make it a DT interrupt controller

[Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

Fix the DT binding documentation to describe interrupt-related properties,
and the contents of "child" node interrupts property.

Update tegra20.dtsi to specify the required interrupt-related properties.

Fix the driver to creating an IRQ domain for itself, so that child node
interrupts properties are correctly parsed.

Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
This patch depends on "arm/tegra: convert tegra20 to GIC devicetree binding",
at least for context, and probably functionally (and of course patch 1 in
this series).

I've tested that this patch causes the WM8903 to receive a valid IRQ when
instantiated from device-tree (although the patches to instantiate the
WM8903 from DT are local to me for now).

 .../devicetree/bindings/gpio/gpio_nvidia.txt       |   10 ++++++++++
 arch/arm/boot/dts/tegra20.dtsi                     |    2 ++
 drivers/gpio/gpio-tegra.c                          |    4 ++++
 3 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
index eb4b530..ecdf19c 100644
--- a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
@@ -6,3 +6,13 @@ Required properties:
   second cell is used to specify optional parameters:
   - bit 0 specifies polarity (0 for normal, 1 for inverted)
 - gpio-controller : Marks the device node as a GPIO controller.
+- #interrupt-cells : Should be 3.
+  The first cell is the GPIO number.
+  The second cell is used to specify flags:
+    bits[3:0] trigger type and level flags:
+      1 = low-to-high edge triggered.
+      2 = high-to-low edge triggered.
+      4 = active high level-sensitive.
+      8 = active low level-sensitive.
+      Valid combinations are 1, 2, 3, 4, 8.
+- interrupt-controller : Marks the device node as an interrupt controller.
diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
index db6f562..e25f4a6 100644
--- a/arch/arm/boot/dts/tegra20.dtsi
+++ b/arch/arm/boot/dts/tegra20.dtsi
@@ -79,6 +79,8 @@
 			       0 55 0x04
 			       0 87 0x04
 			       0 89 0x04 >;
+		interrupt-controller;
+		#interrupt-cells = <2>;
 		#gpio-cells = <2>;
 		gpio-controller;
 	};
diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index 61044c8..26b0c85 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -25,6 +25,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/irqdomain.h>
 
 #include <asm/mach/irq.h>
 
@@ -410,6 +411,9 @@ static int __devinit tegra_gpio_probe(struct platform_device *pdev)
 			spin_lock_init(&bank->lvl_lock[j]);
 	}
 
+	if (pdev->dev.of_node)
+		irq_domain_add_simple(pdev->dev.of_node, TEGRA_GPIO_TO_IRQ(0));
+
 	return 0;
 }
 
-- 
1.7.0.4