Re: [PATCH v8 2/3] Documentation: Add binding document for Lattice iCE40 FPGA manager

From: Marek Vasut
Date: Mon Nov 07 2016 - 13:21:19 EST


On 11/07/2016 03:49 AM, Joel Holdsworth wrote:
> This adds documentation of the device tree bindings of the Lattice iCE40
> FPGA driver for the FPGA manager framework.
>
> Signed-off-by: Joel Holdsworth <joel@xxxxxxxxxxxxxxxxxxx>
> ---
> .../bindings/fpga/lattice-ice40-fpga-mgr.txt | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt
>
> diff --git a/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt b/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt
> new file mode 100644
> index 0000000..7e7a78b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt
> @@ -0,0 +1,21 @@
> +Lattice iCE40 FPGA Manager
> +
> +Required properties:
> +- compatible: Should contain "lattice,ice40-fpga-mgr"
> +- reg: SPI chip select
> +- spi-max-frequency: Maximum SPI frequency (>=1000000, <=25000000)
> +- cdone-gpios: GPIO input connected to CDONE pin
> +- reset-gpios: Active-low GPIO output connected to CRESET_B pin. Note
> + that unless the GPIO is held low during startup, the
> + FPGA will enter Master SPI mode and drive SCK with a
> + clock signal potentially jamming other devices on the
> + bus until the firmware is loaded.
> +
> +Example:
> + ice40: ice40@0 {
> + compatible = "lattice,ice40-fpga-mgr";
> + reg = <0>;
> + spi-max-frequency = <1000000>;
> + cdone-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
> + reset-gpios = <&gpio 22 GPIO_ACTIVE_LOW>;

Wouldn't it make more sense to have "gpios" and "gpio-names" ? That
scales better imo, although in this case we cannot really talk about
scaling.

> + };
>


--
Best regards,
Marek Vasut