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Subject[PATCH 3/3] ARM: gic: add OF based initialization
Date
From: Rob Herring <rob.herring@calxeda.com>

This adds ARM gic interrupt controller initialization using device tree
data.

The initialization function is intended to be called by of_irq_init
function like this:

const static struct of_device_id irq_match[] = {
{ .compatible = "arm,cortex-a9-gic", .data = gic_of_init, },
{}
};
static void __init init_irqs(void)
{
of_irq_init(irq_match);
}
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
Documentation/devicetree/bindings/arm/gic.txt | 55 ++++++++++++++++++++++
arch/arm/common/gic.c | 61 +++++++++++++++++++++++++
arch/arm/include/asm/hardware/gic.h | 1 +
3 files changed, 117 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/gic.txt
diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
new file mode 100644
index 0000000..52916b4
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -0,0 +1,55 @@
+* ARM Generic Interrupt Controller
+
+ARM SMP cores are often associated with a GIC, providing per processor
+interrupts (PPI), shared processor interrupts (SPI) and software
+generated interrupts (SGI).
+
+Primary GIC is attached directly to the CPU and typically has PPIs and SGIs.
+Secondary GICs are cascaded into the upward interrupt controller and do not
+have PPIs or SGIs.
+
+Main node required properties:
+
+- compatible : should be one of:
+ "arm,cortex-a9-gic"
+ "arm,arm11mp-gic"
+- interrupt-controller : Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+ interrupt source. The type shall be a <u32> and the value shall be 3.
+
+ The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
+ interrupts.
+
+ The 2nd cell contains the interrupt number for the interrupt type.
+ SPI interrupts are in the range [0-987]. PPI interrupts are in the
+ range [0-15].
+
+ The 3rd cell is the flags, encoded as follows:
+ 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
+ bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of
+ the 8 possible cpus attached to the GIC. A bit set to '1' indicated
+ the interrupt is wired to that CPU. Only valid for PPI interrupts.
+
+- reg : Specifies base physical address(s) and size of the GIC registers. The
+ first region is the GIC distributor register base and size. The 2nd region is
+ the GIC cpu interface register base and size.
+
+Optional
+- interrupts : Interrupt source of the parent interrupt controller. Only
+ present on secondary GICs.
+
+Example:
+
+ intc: interrupt-controller@fff11000 {
+ compatible = "arm,cortex-a9-gic";
+ #interrupt-cells = <3>;
+ #address-cells = <1>;
+ interrupt-controller;
+ reg = <0xfff11000 0x1000>,
+ <0xfff10100 0x100>;
+ };
+
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 6fbe1db..3e67970 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -29,6 +29,9 @@
#include <linux/cpu_pm.h>
#include <linux/cpumask.h>
#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <linux/irqdomain.h>

#include <asm/irq.h>
@@ -518,7 +521,33 @@ static void __init gic_pm_init(struct gic_chip_data *gic)
}
#endif

+#ifdef CONFIG_OF
+static int gic_irq_domain_dt_translate(struct irq_domain *d,
+ struct device_node *controller,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq, unsigned int *out_type)
+{
+ if (d->of_node != controller)
+ return -EINVAL;
+ if (intsize < 3)
+ return -EINVAL;
+
+ /* Get the interrupt number and add 16 to skip over SGIs */
+ *out_hwirq = intspec[1] + 16;
+
+ /* For SPIs, we need to add 16 more to get the GIC irq ID number */
+ if (!intspec[0])
+ *out_hwirq += 16;
+
+ *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+ return 0;
+}
+#endif
+
const struct irq_domain_ops gic_irq_domain_ops = {
+#ifdef CONFIG_OF
+ .dt_translate = gic_irq_domain_dt_translate,
+#endif
};

void __init gic_init(unsigned int gic_nr, unsigned int irq_start,
@@ -606,3 +635,35 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
writel_relaxed(map << 16 | irq, gic_data[0].dist_base + GIC_DIST_SOFTINT);
}
#endif
+
+#ifdef CONFIG_OF
+static int gic_cnt __initdata = 0;
+
+int __init gic_of_init(struct device_node *node, struct device_node *parent)
+{
+ void __iomem *cpu_base;
+ void __iomem *dist_base;
+ int irq;
+ struct irq_domain *domain = &gic_data[gic_cnt].domain;
+
+ if (WARN_ON(!node))
+ return -ENODEV;
+
+ dist_base = of_iomap(node, 0);
+ WARN(!dist_base, "unable to map gic dist registers\n");
+
+ cpu_base = of_iomap(node, 1);
+ WARN(!cpu_base, "unable to map gic cpu registers\n");
+
+ domain->of_node = of_node_get(node);
+
+ gic_init(gic_cnt, 16, dist_base, cpu_base);
+
+ if (parent) {
+ irq = irq_of_parse_and_map(node, 0);
+ gic_cascade_irq(gic_cnt, irq);
+ }
+ gic_cnt++;
+ return 0;
+}
+#endif
diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
index ade84a4..1a776a1 100644
--- a/arch/arm/include/asm/hardware/gic.h
+++ b/arch/arm/include/asm/hardware/gic.h
@@ -39,6 +39,7 @@ extern void __iomem *gic_cpu_base_addr;
extern struct irq_chip gic_arch_extn;

void gic_init(unsigned int, unsigned int, void __iomem *, void __iomem *);
+int gic_of_init(struct device_node *node, struct device_node *parent);
void gic_secondary_init(unsigned int);
void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
void gic_raise_softirq(const struct cpumask *mask, unsigned int irq);
--
1.7.5.4


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