Commit b3f7ed03 authored by Rob Herring's avatar Rob Herring Committed by Arnd Bergmann
Browse files

ARM: gic: add OF based initialization 



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: default avatarRob Herring <rob.herring@calxeda.com>
Reviewed-by: default avatarJamie Iles <jamie@jamieiles.com>
Tested-by: default avatarThomas Abraham <thomas.abraham@linaro.org>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 4294f8ba

Documentation/devicetree/bindings/arm/gic.txt

0 → 100644
+55 −0
Original line number Diff line number Diff line 
* 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>;

	};

arch/arm/common/gic.c

+61 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ 
#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 <linux/interrupt.h>

#include <linux/percpu.h>
@@ -530,7 +533,33 @@ 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,
@@ -608,3 +637,35 @@ 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

arch/arm/include/asm/hardware/gic.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 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);

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