[PATCH 3/3] ARM: gic: add OF based initialization
Grant Likely
grant.likely at secretlab.ca
Tue Sep 20 19:08:00 EDT 2011
On Tue, Sep 20, 2011 at 03:24:04PM -0500, Rob Herring wrote:
> From: Rob Herring <rob.herring at 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 at calxeda.com>
> ---
> Documentation/devicetree/bindings/arm/gic.txt | 55 +++++++++++++++
> arch/arm/common/gic.c | 89 +++++++++++++++++++++++-
> arch/arm/include/asm/hardware/gic.h | 12 ++++
> 3 files changed, 152 insertions(+), 4 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 at fff11000 {
> + compatible = "arm,cortex-a9-gic";
> + #interrupt-cells = <3>;
> + #address-cells = <1>;
> + interrupt-controller;
> + reg = <0xfff11000 0x1000>,
> + <0xfff10100 0x100>;
> + };
> +
Ack on the binding.
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index 666b278..84e69a4 100644
> --- a/arch/arm/common/gic.c
> +++ b/arch/arm/common/gic.c
> @@ -28,6 +28,10 @@
> #include <linux/smp.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>
> #include <asm/mach/irq.h>
> @@ -255,6 +259,15 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
> irq_set_chained_handler(irq, gic_handle_cascade_irq);
> }
>
> +static int gic_irq_count(void __iomem *dist_base)
> +{
> + int gic_irqs = readl_relaxed(dist_base + GIC_DIST_CTR) & 0x1f;
> + gic_irqs = (gic_irqs + 1) * 32;
> + if (gic_irqs > 1020)
> + gic_irqs = 1020;
> + return gic_irqs;
> +}
> +
> static void __init gic_dist_init(struct gic_chip_data *gic,
> unsigned int irq_start)
> {
> @@ -277,10 +290,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
> * Find out how many interrupts are supported.
> * The GIC only supports up to 1020 interrupt sources.
> */
> - gic_irqs = readl_relaxed(base + GIC_DIST_CTR) & 0x1f;
> - gic_irqs = (gic_irqs + 1) * 32;
> - if (gic_irqs > 1020)
> - gic_irqs = 1020;
> + gic_irqs = gic_irq_count(base);
>
> /*
> * Set all global interrupts to be level triggered, active low.
> @@ -405,3 +415,74 @@ 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 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)
> +{
> + struct gic_chip_data *gic_data = d->priv;
> +
> + if (d->of_node != controller)
> + return -EINVAL;
> + if (intsize < 3)
> + return -EINVAL;
> +
> + *out_hwirq = intspec[1];
> + /*
> + * We've already skipped over SGIs, so PPIs need no translation.
> + * For SPIs, we need to skip over 16 PPIs on primary GICs.
> + */
> + if (!intspec[0] && !gic_data->irq_offset)
> + *out_hwirq += 16;
I though that the offset was 32 to get from SPI number to Interrrupt
ID? And that PPI interrupts start at Interrupt ID 16? Or am I
mistaken about the hwirq number that this driver uses internally?
Otherwise, the change looks about right to me.
g.
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