[RFC PATCH 2/6] DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP

[Kumar Gala]

On Sep 30, 2013, at 8:59 AM, Sricharan R wrote:

> Some socs have a large number of interrupts requests to service
> the needs of its many peripherals and subsystems. All of the
> interrupt lines from the subsystems are not needed at the same
> time, so they have to be muxed to the irq-controller appropriately.
> In such places a interrupt controllers are preceded by an CROSSBAR
> that provides flexibility in muxing the device requests to the controller
> inputs.
> 
> This driver takes care a allocating a free irq and then configuring the
> crossbar IP as a part of the mpu's irqchip callbacks. crossbar_init should
> be called right before the irqchip_init, so that it is setup to handle the
> irqchip callbacks.
> 
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Linus Walleij <linus.walleij at linaro.org>
> Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
> Cc: Russell King <linux at arm.linux.org.uk>
> Cc: Tony Lindgren <tony at atomide.com>
> Cc: Rajendra Nayak <rnayak at ti.com>
> Cc: Marc Zyngier <marc.zyngier at arm.com>
> Cc: Grant Likely <grant.likely at linaro.org>
> Cc: Rob Herring <rob.herring at calxeda.com>
> Signed-off-by: Sricharan R <r.sricharan at ti.com>
> ---
> .../devicetree/bindings/arm/omap/crossbar.txt      |   27 +++
> drivers/irqchip/Kconfig                            |    8 +
> drivers/irqchip/Makefile                           |    1 +
> drivers/irqchip/irq-crossbar.c                     |  195 ++++++++++++++++++++
> include/linux/irqchip/irq-crossbar.h               |   11 ++
> 5 files changed, 242 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/omap/crossbar.txt
> create mode 100644 drivers/irqchip/irq-crossbar.c
> create mode 100644 include/linux/irqchip/irq-crossbar.h
> 
> diff --git a/Documentation/devicetree/bindings/arm/omap/crossbar.txt b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
> new file mode 100644
> index 0000000..cdec2cd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
> @@ -0,0 +1,27 @@
> +Some socs have a large number of interrupts requests to service
> +the needs of its many peripherals and subsystems. All of the
> +interrupt lines from the subsystems are not needed at the same
> +time, so they have to be muxed to the irq-controller appropriately.
> +In such places a interrupt controllers are preceded by an CROSSBAR
> +that provides flexibility in muxing the device requests to the controller
> +inputs.
> +
> +Required properties:
> +- compatible : Should be "ti,irq-crossbar"
> +- reg: Base address and the size of the crossbar registers.
> +- max-irqs: Total number of irqs available at the interrupt controller.

Should be 'ti,max-irqs

> +- reg-size: Size of a individual register in bytes. Every individual
> +	    register is assumed to be of same size. Valid sizes are 1, 2, 4.

Is this something that really needs to be encoded in the dts?

If we keep it should be ti,reg-size

> +- irqs-reserved: List of the reserved irq lines that are not muxed using
> +		 crossbar. These interrupt lines are reserved in the soc,
> +		 so crossbar bar driver should not consider them as free
> +		 lines.
> +

ti,irqs-reserved

> +Examples:
> +		crossbar_mpu: @4a020000 {

Did you mean for there to be a label and no node name?

> +			compatible = "ti,irq-crossbar";
> +			reg = <0x4a002a48 0x130>;
> +			max-irqs = <160>;
> +			reg-size = <2>;
> +			irqs-reserved = <0 1 2 3 5 6 131 132 139 140>;
> +		};

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