[PATCH 3/6] ARM: plat-versatile: add DT support to FPGA IRQ controller
Linus Walleij
linus.walleij at linaro.org
Thu Aug 16 22:15:57 EST 2012
This adds Device Tree probing support to the Versatile FPGA
IRQ controller.
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
.../devicetree/bindings/arm/versatile-fpga-irq.txt | 35 ++++++++++++++++++
arch/arm/plat-versatile/fpga-irq.c | 41 ++++++++++++++++++++++
arch/arm/plat-versatile/include/plat/fpga-irq.h | 2 ++
3 files changed, 78 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
diff --git a/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt b/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
new file mode 100644
index 0000000..d20242a
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
@@ -0,0 +1,35 @@
+* ARM Versatile FPGA interrupt controller
+
+One or more FPGA IRQ controllers can be synthesized in an ARM reference board
+such as the Integrator or Versatile family. The output of these different
+controllers are OR:ed together and fed to the CPU tile's IRQ input. Each
+instance can handle up to 32 interrupts.
+
+Required properties:
+- compatible: "arm,versatile-fpga-irq"
+- interrupt-controller: Identifies the node as an interrupt controller
+- #interrupt-cells: The number of cells to define the interrupts. Must be 1
+ as the FPGA IRQ controller has no configuration options for interrupt
+ sources. The cell is a u32 and defines the interrupt number.
+- reg: The register bank for the FPGA interrupt controller.
+- irq-start: the u32 hardware IRQ number of the first interrupt handled by
+ this FPGA IRQ instance - since there may be many FPGA IRQ controller
+ instances, each will have its unique hardware offset number.
+- clear-mask: a u32 number representing the mask written to clear all IRQs
+ on the controller at boot for example.
+- valid-mask: a u32 number representing a bit mask determining which of
+ the interrupts are valid. Unconnected/unused lines are set to 0, and
+ the system till not make it possible for devices to request these
+ interrupts.
+
+Example:
+
+pic: pic at 14000000 {
+ compatible = "arm,versatile-fpga-irq";
+ #interrupt-cells = <1>;
+ interrupt-controller;
+ reg = <0x14000000 0x100>;
+ irq-start = <1>;
+ clear-mask = <0xffffffff>;
+ valid-mask = <0x003fffff>;
+};
diff --git a/arch/arm/plat-versatile/fpga-irq.c b/arch/arm/plat-versatile/fpga-irq.c
index 6e70d03..379ff53 100644
--- a/arch/arm/plat-versatile/fpga-irq.c
+++ b/arch/arm/plat-versatile/fpga-irq.c
@@ -5,6 +5,8 @@
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
@@ -14,6 +16,13 @@
#define IRQ_RAW_STATUS 0x04
#define IRQ_ENABLE_SET 0x08
#define IRQ_ENABLE_CLEAR 0x0c
+#define INT_SOFT_SET 0x10
+#define INT_SOFT_CLEAR 0x14
+#define FIQ_STATUS 0x20
+#define FIQ_RAW_STATUS 0x24
+#define FIQ_ENABLE 0x28
+#define FIQ_ENABLE_SET 0x28
+#define FIQ_ENABLE_CLEAR 0x2C
/**
* struct fpga_irq_data - irq data container for the FPGA IRQ controller
@@ -156,3 +165,35 @@ void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
fpga_irq_id++;
}
+
+#ifdef CONFIG_OF
+int __init fpga_irq_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ void __iomem *base;
+ u32 irq_start;
+ u32 clear_mask;
+ u32 valid_mask;
+
+ if (WARN_ON(!node))
+ return -ENODEV;
+
+ base = of_iomap(node, 0);
+ WARN(!base, "unable to map fpga irq registers\n");
+
+ if (of_property_read_u32(node, "irq-start", &irq_start))
+ irq_start = 0;
+
+ if (of_property_read_u32(node, "clear-mask", &clear_mask))
+ clear_mask = 0;
+
+ if (of_property_read_u32(node, "valid-mask", &valid_mask))
+ valid_mask = 0;
+
+ writel(clear_mask, base + IRQ_ENABLE_CLEAR);
+ writel(clear_mask, base + FIQ_ENABLE_CLEAR);
+ fpga_irq_init(base, node->name, irq_start, -1, valid_mask, node);
+
+ return 0;
+}
+#endif
diff --git a/arch/arm/plat-versatile/include/plat/fpga-irq.h b/arch/arm/plat-versatile/include/plat/fpga-irq.h
index 91bcfb6..1fac965 100644
--- a/arch/arm/plat-versatile/include/plat/fpga-irq.h
+++ b/arch/arm/plat-versatile/include/plat/fpga-irq.h
@@ -7,5 +7,7 @@ struct pt_regs;
void fpga_handle_irq(struct pt_regs *regs);
void fpga_irq_init(void __iomem *, const char *, int, int, u32,
struct device_node *node);
+int fpga_irq_of_init(struct device_node *node,
+ struct device_node *parent);
#endif
--
1.7.11.2
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