[PATCH 1/2] versatile: sic: add device tree bindings

[Jamie Iles]

Add a device tree binding for the FPGA SIC on versatile platforms.  This
also requires the addition of irq domain support for mapping to Linux
IRQs.

Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: Russell King <linux at arm.linux.org.uk>
Signed-off-by: Jamie Iles <jamie at jamieiles.com>
---
 .../devicetree/bindings/arm/versatile-sic.txt      |   27 ++++++++++
 arch/arm/plat-versatile/Kconfig                    |    1 +
 arch/arm/plat-versatile/fpga-irq.c                 |   51 +++++++++++++++++++-
 arch/arm/plat-versatile/include/plat/fpga-irq.h    |    6 ++
 4 files changed, 83 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/versatile-sic.txt

diff --git a/Documentation/devicetree/bindings/arm/versatile-sic.txt b/Documentation/devicetree/bindings/arm/versatile-sic.txt
new file mode 100644
index 0000000..971a42e
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/versatile-sic.txt
@@ -0,0 +1,27 @@
+* ARM Versatile FPGA Secondary Interrupt Controller
+
+The SIC is an interrupt controller embedded in an FPGA found on ARM versatile
+platforms.
+
+Required properties:
+
+- compatible : "arm,versatile-sic"
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : The number of cells to define the interrupts.  Must be 1 as
+  the SIC has no configuration options for interrupt sources.  The cell is a u32
+  and defines the interrupt number.
+- reg : The register bank for the VIC.
+- interrupt-parent : The interrupt controller that IRQ's are cascaded to.
+- interrupts : Interrupt source for the interrupt that SIC IRQs are routed to
+  in the primary interrupt controller.
+
+Example:
+
+	sic: intc at 10003000 {
+		compatible = "arm,versatile-sic";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		reg = <0x10003000 0x1000>;
+		interrupt-parent = <&vic>;
+		interrupts = <31>;
+	};
diff --git a/arch/arm/plat-versatile/Kconfig b/arch/arm/plat-versatile/Kconfig
index 52353be..a07ffe5 100644
--- a/arch/arm/plat-versatile/Kconfig
+++ b/arch/arm/plat-versatile/Kconfig
@@ -4,6 +4,7 @@ config PLAT_VERSATILE_CLCD
 	bool
 
 config PLAT_VERSATILE_FPGA_IRQ
+	select IRQ_DOMAIN
 	bool
 
 config PLAT_VERSATILE_LEDS
diff --git a/arch/arm/plat-versatile/fpga-irq.c b/arch/arm/plat-versatile/fpga-irq.c
index f0cc8e1..fd87b06 100644
--- a/arch/arm/plat-versatile/fpga-irq.c
+++ b/arch/arm/plat-versatile/fpga-irq.c
@@ -2,7 +2,13 @@
  *  Support for Versatile FPGA-based IRQ controllers
  */
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
 
 #include <asm/mach/irq.h>
 #include <plat/fpga-irq.h>
@@ -15,7 +21,7 @@
 static void fpga_irq_mask(struct irq_data *d)
 {
 	struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
-	u32 mask = 1 << (d->irq - f->irq_start);
+	u32 mask = 1 << d->hwirq;
 
 	writel(mask, f->base + IRQ_ENABLE_CLEAR);
 }
@@ -23,7 +29,7 @@ static void fpga_irq_mask(struct irq_data *d)
 static void fpga_irq_unmask(struct irq_data *d)
 {
 	struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
-	u32 mask = 1 << (d->irq - f->irq_start);
+	u32 mask = 1 << d->hwirq;
 
 	writel(mask, f->base + IRQ_ENABLE_SET);
 }
@@ -53,6 +59,10 @@ void __init fpga_irq_init(int parent_irq, u32 valid, struct fpga_irq_data *f)
 	f->chip.irq_ack = fpga_irq_mask;
 	f->chip.irq_mask = fpga_irq_mask;
 	f->chip.irq_unmask = fpga_irq_unmask;
+	f->domain.irq_base = f->irq_start;
+	f->domain.nr_irq = 32;
+	f->domain.ops = &irq_domain_simple_ops;
+	irq_domain_add(&f->domain);
 
 	if (parent_irq != -1) {
 		irq_set_handler_data(parent_irq, f);
@@ -70,3 +80,40 @@ void __init fpga_irq_init(int parent_irq, u32 valid, struct fpga_irq_data *f)
 		}
 	}
 }
+
+#ifdef CONFIG_OF
+int __init sic_of_init(struct device_node *np, struct device_node *parent)
+{
+	struct fpga_irq_data *sic_data = kzalloc(sizeof(*sic_data), GFP_KERNEL);
+	int err = -ENOMEM, irq;
+
+	if (WARN_ON(!sic_data))
+		return err;
+
+	sic_data->base = of_iomap(np, 0);
+	if (WARN_ON(!sic_data->base))
+		goto out_free_data;
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (irq < 0)
+		goto out_free_data;
+
+	sic_data->irq_start = irq_alloc_descs(-1, 0, 32, numa_node_id());
+	if (WARN_ON(sic_data->irq_start < 0)) {
+		err = sic_data->irq_start;
+		goto out_unmap;
+	}
+	sic_data->domain.of_node = of_node_get(np);
+
+	fpga_irq_init(irq, ~0, sic_data);
+
+	return 0;
+
+out_unmap:
+	iounmap(sic_data->base);
+out_free_data:
+	kfree(sic_data);
+
+	return err;
+}
+#endif /* CONFIG_OF */
diff --git a/arch/arm/plat-versatile/include/plat/fpga-irq.h b/arch/arm/plat-versatile/include/plat/fpga-irq.h
index 627fafd..a1391f3 100644
--- a/arch/arm/plat-versatile/include/plat/fpga-irq.h
+++ b/arch/arm/plat-versatile/include/plat/fpga-irq.h
@@ -1,12 +1,18 @@
 #ifndef PLAT_FPGA_IRQ_H
 #define PLAT_FPGA_IRQ_H
 
+#include <linux/irqdomain.h>
+
+struct device_node;
+
 struct fpga_irq_data {
 	void __iomem *base;
 	unsigned int irq_start;
 	struct irq_chip chip;
+	struct irq_domain domain;
 };
 
 void fpga_irq_init(int, u32, struct fpga_irq_data *);
+int sic_of_init(struct device_node *np, struct device_node *parent);
 
 #endif
-- 
1.7.5.4