Re: [PATCH v5] arm: pxa: support ICP DAS LP-8x4x FPGA irq

Rob Herring
2015-12-19T04:20:10Z

On Tue, Dec 15, 2015 at 10:26:21PM +0300, Sergei Ianovich wrote:
> ICP DAS LP-8x4x contains FPGA chip. The chip functions as an interrupt
> source providing 16 additional interrupts among other things. The
> interrupt lines are muxed to a GPIO pin of a 2nd level PXA-GPIO
> interrupt controller. GPIO pins of the 2nd level controller are in turn
> muxed to a CPU interrupt line.
>
> Until pxa is completely converted to device tree, it is impossible
> to use IRQCHIP_DECLARE() and the irqdomain needs to added manually.
> Drivers for the on-CPU IRQs and GPIO-IRQs are loaded using
> postcore_initcall(). We need to have all irq domain drivers loaded prior
> to DT parsing in order to allow normal initialization of IRQ resources
> with DT.
>
> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> CC: Arnd Bergmann <arnd@arndb.de>
> ---
> v4..v5
> * constify struct of_device_id
> * drop irq number from handler signature
>
> v3.2..v4
> * move DTS binding to a different patch (8/21)
>
> v3.1..v3.2
> fixes to apply Linus Walleij's "Reviewed-by":
> * add kerneldoc comment for state container struct
> * rename irq -> hwirq for clarity
> * drop overzealous error checks from the hotpaths
>
> v3..v3.1
> fixes according to Linus Walleij review comments:
> * update commit message
> * use state container instead of global variables
> * get hardware irq nums from irq_data, don't calculate them
> * use BIT() macro
> * add defines for system irq register masks
> * replace cycle control variable with break
> * use better names for resource variables
> * add a linear domain instead of a legacy one
> * use irq_create_mapping() instead of irq_alloc_desc()
>
> v2..v3
> * no changes (except number 09/16 -> 11/21)
>
> v0..v2
> * extract irqchip and move to drivers/irqchip/
> * use device tree
> * use devm helpers where possible
>
> .../bindings/interrupt-controller/irq-lp8x4x.txt | 49 +++++
> drivers/irqchip/Kconfig | 5 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-lp8x4x.c | 227 +++++++++++++++++++++
> 4 files changed, 282 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
> create mode 100644 drivers/irqchip/irq-lp8x4x.c
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
> new file mode 100644
> index 0000000..c8940d2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/irq-lp8x4x.txt
> @@ -0,0 +1,49 @@
> +ICP DAS LP-8x4x FPGA Interrupt Controller
> +
> +ICP DAS LP-8x4x contains FPGA chip. The chip functions as a interrupt
> +source providing 16 additional interrupts among other things.
> +
> +Required properties:
> +- compatible : should be "icpdas,irq-lp8x4x"
> +
> +- reg: physical base address of the controller and length of memory mapped
> + region.
> +
> +- interrupt-controller : identifies the node as an interrupt controller
> +
> +- #interrupt-cells : should be 1
> +
> +- interrupts : should provide interrupt
> +
> +- interrupt-parent : should provide a link to interrupt controller either
> + explicitly and implicitly from a parent node
> +
> +Example:
> +
> + fpga: fpga@17000006 {

Nothing else in the fpga? In any case, this node should be named
interrupt-controller@17000006.

> + compatible = "icpdas,irq-lp8x4x";

As pointed out in the uart binding, don't use wildcards here.

> + reg = <0x17000006 0x16>;
> + interrupt-parent = <&gpio>;
> + interrupts = <3 IRQ_TYPE_EDGE_RISING>;
> + #interrupt-cells = <1>;
> + interrupt-controller;
> + status = "okay";
> + };
> +
> + uart@17009050 {
> + compatible = "icpdas,uart-lp8x4x";
> + reg = <0x17009050 0x10
> + 0x17009030 0x02>;
> + interrupt-parent = <&fpga>;
> + interrupts = <13>;
> + status = "okay";
> + };