Re: [PATCH V2 2/3] dt-bindings: gpio: zynqmp: Add binding documentation for modepin

From: Rob Herring
Date: Fri Aug 13 2021 - 15:01:54 EST


On Thu, Aug 05, 2021 at 11:12:18PM +0530, Piyush Mehta wrote:
> This patch adds DT binding document for zynqmp modepin GPIO controller.
> Modepin GPIO controller has four GPIO pins which can be configurable
> as input or output.
>
> Modepin driver is a bridge between the peripheral driver and GPIO pins.
> It has set and get APIs for accessing GPIO pins, based on the device-tree
> entry of reset-gpio property in the peripheral driver, every pin can be
> configured as input/output and trigger GPIO pin.
>
> For more information please refer zynqMp TRM link:
> Link: https://www.xilinx.com/support/documentation/user_guides/ug1085-zynq-ultrascale-trm.pdf
> Chapter 2: Signals, Interfaces, and Pins
> Table 2-2: Clock, Reset, and Configuration Pins - PS_MODE
>
> Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxxxxx>
> ---
> Changes in v2:
> - Addressed review comments: Update commit message
>
> https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xxxxxxxxxx/T/#mbd1fbda813e33b19397b350bde75747c92a0d7e1
> https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xxxxxxxxxx/T/#me82b1444ab3776162cdb0077dfc9256365c7e736
> ---
> .../bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml | 41 ++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml
>
> diff --git a/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml b/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml
> new file mode 100644
> index 0000000..39d78f8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/xlnx,zynqmp-gpio-modepin.yaml
> @@ -0,0 +1,41 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/gpio/xlnx,zynqmp-gpio-modepin.yaml#";
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#";
> +
> +title: ZynqMP Mode Pin GPIO controller
> +
> +description:
> + PS_MODE is 4-bits boot mode pins sampled on POR deassertion. Mode Pin
> + GPIO controller with configurable from numbers of pins (from 0 to 3 per
> + PS_MODE). Every pin can be configured as input/output.
> +
> +maintainers:
> + - Piyush Mehta <piyush.mehta@xxxxxxxxxx>
> +
> +properties:
> + compatible:
> + const: xlnx,zynqmp-gpio-modepin
> +
> + gpio-controller: true
> +
> + "#gpio-cells":
> + const: 2
> +
> +required:
> + - compatible
> + - gpio-controller
> + - "#gpio-cells"
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + modepin_gpio: gpio {
> + compatible = "xlnx,zynqmp-gpio-modepin";
> + gpio-controller;
> + #gpio-cells = <2>;

No way to interact with this h/w?

As it is part of the firmware interface, it must be a child node in the
firmware node schema.

> + };
> +
> +...
> --
> 2.7.4
>
>