Re: [PATCH v2] ARM: gic: add OF based initialization

[Rob Herring <robherring2@gmail.com>]

On 08/25/2011 04:49 PM, Rob Herring wrote:
> From: Rob Herring <rob.herring@calxeda.com>
> 
> This adds gic initialization using device tree data. The initialization
> functions are intended to be called by a generic OF interrupt
> controller parsing function once the right pieces are in place.
> 
> PPI binding support based on work by Marc Zyngier.
> 
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> ---
> Changes in v2:
> - Add bindings and documentation for PPI
> - change interrupt-cells to 2
> - Move init of np pointer to after intc_desc ptr NULL check
> 
>  Documentation/devicetree/bindings/arm/gic.txt |   62 +++++++++++++++++++++++++
>  arch/arm/common/gic.c                         |   41 ++++++++++++++++
>  arch/arm/include/asm/hardware/gic.h           |    3 +
>  3 files changed, 106 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..85be7c9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/gic.txt
> @@ -0,0 +1,62 @@
> +* 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. Secondary GICs are
> +cascaded into the upward interrupt controller and do not have PPIs.
> +
> +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 2.

I need to add the following level sense info. I'm using the same values
as IRQF_TRIGGER_* as suggested by Grant.

 The 2nd cell contains the level-sense information, encoded as follows:
                    1 = low-to-high edge triggered
                    2 = high-to-low edge triggered
                    4 = active high level-sensitive
                    8 = active low level-sensitive

> +- reg : Specifies base physical address(s) and size of the GIC registers. The
> +  first 2 values are the GIC distributor register base and size. The 2nd 2
> +  values are the GIC cpu interface register base and size.
> +- #size-cells : Shall be <0> as PPIs don't have size for reg property. Optional
> +  for secondary GICs.
> +
> +Optional
> +- interrupts	: optional, used on secondary GICs only
> +
> +PPI sub-nodes required properties:
> +
> +- compatible : should match the main node with "-ppi" appended. one of:
> +	"arm,cortex-a9-gic-ppi"
> +	"arm,arm11mp-gic-ppi"
> +- 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 1 as PPIs
> +  don't have edge/level settings.
> +- reg : Specifies cpu number the PPIs are attached to.
> +
> +Example:
> +
> +	intc: interrupt-controller@fff11000 {
> +		compatible = "arm,cortex-a9-gic";
> +		#interrupt-cells = <2>;
> +		#size-cells = <0>;
> +		#address-cells = <1>;
> +		interrupt-controller;
> +		reg = <0xfff11000 0x1000>,
> +		      <0xfff10100 0x100>;
> +		      
> +		gicppi0: gic-ppi@0 {
> +			compatible = "arm,cortex-a9-gic-ppi";
> +			#interrupt-cells = <1>;
> +			interrupt-controller;
> +			reg = <0>;
> +		};
> +		gicppi1: gic-ppi@1 {
> +			compatible = "arm,cortex-a9-gic-ppi";
> +			#interrupt-cells = <1>;
> +			interrupt-controller;
> +			reg = <1>;
> +		};
> +	};
> +
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index f13298e..a796299 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>
> @@ -394,3 +398,40 @@ 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;
> +
> +void __init gic_of_init(struct of_intc_desc *d)
> +{
> +	struct device_node *np;
> +	void __iomem *cpu_base;
> +	void __iomem *dist_base;
> +	int irq;
> +
> +	if (WARN_ON(!d || !d->controller))
> +		return;
> +
> +	np = d->controller;
> +	dist_base = of_iomap(np, 0);
> +	WARN(!dist_base, "unable to map gic dist registers\n");
> +
> +	cpu_base = of_iomap(np, 1);
> +	WARN(!cpu_base, "unable to map gic cpu registers\n");
> +
> +	gic_init(gic_cnt, d->irq_base, dist_base, cpu_base);
> +	irq_domain_add_simple(d->controller, d->irq_base);
> +
> +	if (d->parent) {
> +		irq = irq_of_parse_and_map(np, 0);
> +		gic_cascade_irq(gic_cnt, irq);
> +	}
> +	gic_cnt++;
> +}
> +
> +void __init gic_of_ppi_init(struct of_intc_desc *d)
> +{
> +	irq_domain_add_simple(d->controller, d->irq_base);
> +}
> +
> +#endif
> diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
> index 435d3f8..a6594d4 100644
> --- a/arch/arm/include/asm/hardware/gic.h
> +++ b/arch/arm/include/asm/hardware/gic.h
> @@ -37,6 +37,9 @@ 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 *);
> +struct of_intc_desc;
> +void gic_of_init(struct of_intc_desc *d);
> +void gic_of_ppi_init(struct of_intc_desc *d);
>  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);