Re: [PATCH v2 1/2] dt-bindings: usb: misc: Add binding for Microchip usb5744 hub

From: Rob Herring <robh@kernel.org>
To: Michal Simek <michal.simek@xilinx.com>
Cc: linux-kernel@vger.kernel.org, monstr@monstr.eu, git@xilinx.com,
	Piyush Mehta <piyush.mehta@xilinx.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-usb@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: usb: misc: Add binding for Microchip usb5744 hub
Date: Wed, 10 Feb 2021 16:22:41 -0600	[thread overview]
Message-ID: <20210210222241.GA2901449@robh.at.kernel.org> (raw)
In-Reply-To: <076994fc051e9230a3fef9e3eb5ec932104ef16a.1612867682.git.michal.simek@xilinx.com>

On Tue, Feb 09, 2021 at 11:48:09AM +0100, Michal Simek wrote:
> From: Piyush Mehta <piyush.mehta@xilinx.com>
> 
> Added dt binding for usb5744 driver.
> 
> Signed-off-by: Piyush Mehta <piyush.mehta@xilinx.com>
> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> ---
> 
> Changes in v2: None
> 
>  .../bindings/usb/microchip,usb5744.yaml       | 56 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 57 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
> 
> diff --git a/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
> new file mode 100644
> index 000000000000..fe222f6db81d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
> @@ -0,0 +1,56 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/usb/microchip,usb5744.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Bindings for the Microchip USB5744 4-port Hub Controller
> +
> +description:
> +  Microchip’s USB5744 SmartHub™ IC is a 4 port, SuperSpeed (SS)/Hi-Speed (HS),
> +  low power, low pin count configurable and fully compliant with the USB 3.1
> +  Gen 1 specification. The USB5744 also supports Full Speed (FS) and Low Speed
> +  (LS) USB signaling, offering complete coverage of all defined USB operating
> +  speeds. The new SuperSpeed hubs operate in parallel with the USB 2.0
> +  controller, so 5 Gbps SuperSpeed data transfers are not affected by slower
> +  USB 2.0 traffic.
> +
> +maintainers:
> +  - Piyush Mehta <piyush.mehta@xilinx.com>
> +  - Michal Simek <michal.simek@xilinx.com>
> +
> +properties:
> +  compatible:
> +    const: microchip,usb5744
> +
> +  reg:
> +    maxItems: 1
> +    description: |
> +      Specifies the i2c slave address, it is required and should be 0x2d
> +      if I2C is used.

If I2C is not used, then this should be underneath the USB host as a USB 
device. That also implies a different compatible string. I'd suggest you 
just say I2C is required if that's your use.

'const: 0x2d' instead of maxItems is the schema to express the address 
if fixed.

> +
> +  reset-gpios:
> +    maxItems: 1
> +    description:
> +      The phandle and specifier for the GPIO that controls the RESET line of
> +      USB hub.
> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        usb5744@2d {
> +            compatible = "microchip,usb5744";
> +            reg = <0x2d>;
> +            reset-gpios = <&gpio 44 GPIO_ACTIVE_HIGH>;
> +        };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 41e8d3d7faec..7439471b5d37 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2697,6 +2697,7 @@ W:	http://wiki.xilinx.com
>  T:	git https://github.com/Xilinx/linux-xlnx.git
>  F:	Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml
>  F:	Documentation/devicetree/bindings/i2c/xlnx,xps-iic-2.00.a.yaml
> +F:	Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
>  F:	arch/arm/mach-zynq/
>  F:	drivers/block/xsysace.c
>  F:	drivers/clocksource/timer-cadence-ttc.c
> -- 
> 2.30.0
> 