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

From: Rob Herring <robh@kernel.org>
To: Piyush Mehta <piyush.mehta@xilinx.com>
Cc: arnd@arndb.de, zou_wei@huawei.com, gregkh@linuxfoundation.org,
	linus.walleij@linaro.org, michal.simek@xilinx.com,
	wendy.liang@xilinx.com, iwamatsu@nigauri.org,
	bgolaszewski@baylibre.com, rajan.vaja@xilinx.com,
	linux-gpio@vger.kernel.org, devicetree@vger.kernel.org,
	git@xilinx.com, sgoud@xilinx.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 2/3] dt-bindings: gpio: zynqmp: Add binding documentation for modepin
Date: Fri, 13 Aug 2021 14:01:49 -0500	[thread overview]
Message-ID: <YRbBnRS0VosXcZWz@robh.at.kernel.org> (raw)
In-Reply-To: <20210805174219.3000667-3-piyush.mehta@xilinx.com>

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@xilinx.com>
> ---
> Changes in v2:
> - Addressed review comments: Update commit message
> 
> https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xilinx.com/T/#mbd1fbda813e33b19397b350bde75747c92a0d7e1
> https://lore.kernel.org/linux-arm-kernel/20210615080553.2021061-2-piyush.mehta@xilinx.com/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@xilinx.com>
> +
> +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
> 
> 