Re: [PATCH v7 01/13] dt-bindings: phy: Add zx297520v3 USB phy documentation

[Krzysztof Kozlowski <krzk@kernel.org>]

On Fri, Jul 17, 2026 at 12:35:37AM +0300, Stefan Dösinger wrote:
> This binding will be used as a subnode of topcrm, which will be added in
> the next patch.

Irrelevant, drop. Also not true, because next patch is driver patch.

> 
> Why is this a child node and not #phy-cells added to topcrm itself,
> like clocks and resets as writing-bindings.rst suggests? Because
> of_phy_provider_register checks if the of_node the PHY provider is added
> to belongs to the device or is a child of the device, so I can't put the
> PHY driver into an MFD (or AUX) child without its own node.

> 
> Signed-off-by: Stefan Dösinger <stefandoesinger@gmail.com>
> 
> ---
> 
> How do I handle examples? It would be identical to the example in
> topcrm. The example needs the reset defines from the next patch in
> either case.

1. No, it does not need. Just use whatever numbers.
2. Other code would give you the hint: one example in parent's schema.

> ---
>  .../bindings/phy/zte,zx297520v3-usb-phy.yaml       | 96 ++++++++++++++++++++++
>  MAINTAINERS                                        |  2 +
>  include/dt-bindings/phy/phy-zte-zx297520v3-usb.h   | 12 +++
>  3 files changed, 110 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/phy/zte,zx297520v3-usb-phy.yaml b/Documentation/devicetree/bindings/phy/zte,zx297520v3-usb-phy.yaml
> new file mode 100644
> index 000000000000..8bad9365d5cc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/zte,zx297520v3-usb-phy.yaml
> @@ -0,0 +1,96 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/zte,zx297520v3-usb-phy.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ZTE zx297520v3 USB and HSIC PHY
> +
> +maintainers:
> +  - Stefan Dösinger <stefandoesinger@gmail.com>
> +
> +description: |
> +  This PHY is found on zx297520v3 boards. It has no configurability on its own,
> +  but it does require a correct reset and wait sequence to initialize. It can
> +  provide interrupt notification when USB is connected and disconnected.
> +
> +  The phy is a component of the board's topcrm controller. The hardware needs to
> +  be declared as a child node of the zte,zx297520v3-topcrm node.
> +
> +  The register space and IRQs always account for two PHYs: One USB 2.0 OTG phy
> +  and a HSIC PHY. Not all boards have both. If one is missing, the corresponding
> +  ready flag will never be set.
> +
> +  The "include/dt-bindings/phy/phy-zte-zx297520v3-usb.h" header contains the
> +  definition for the PHY indices.
> +
> +properties:
> +  compatible:
> +    const: zte,zx297520v3-usb-phy
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    items:
> +      - description: IRQ reporting USB connection
> +      - description: IRQ reporting USB disconnection
> +      - description: IRQ reporting HSIC connection
> +      - description: IRQ reporting HSIC disconnection
> +
> +  interrupt-names:
> +    items:
> +      - const: usb-up
> +      - const: usb-down
> +      - const: hsic-up
> +      - const: hsic-down
> +
> +  resets:
> +    items:
> +      - description: USB phy reset
> +      - description: HSIC phy reset

Why do you reference here resets from the parent? That's a clear signal
you have one device, so one device node regardless of Linux phy core
behavior.

> +
> +  reset-names:
> +    items:
> +      - const: usb
> +      - const: hsic
> +
> +  "#phy-cells":
> +    const: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - interrupt-names
> +  - resets
> +  - reset-names
> +  - "#phy-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/phy/phy-zte-zx297520v3-usb.h>
> +
> +    topcrm: clock-controller {
> +        compatible = "zte,zx297520v3-topcrm", "syscon";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        #reset-cells = <1>;

Drop node, you have warnings.

> +
> +        usb-phy@84 {
> +          compatible = "zte,zx297520v3-usb-phy";
> +          reg = <0x84>;
> +          interrupts = <GIC_SPI 42 IRQ_TYPE_EDGE_RISING>,
> +            <GIC_SPI 43 IRQ_TYPE_EDGE_RISING>,
> +            <GIC_SPI 45 IRQ_TYPE_EDGE_RISING>,
> +            <GIC_SPI 46 IRQ_TYPE_EDGE_RISING>;

Align it properly/

> +          interrupt-names = "usb-up", "usb-down", "hsic-up", "hsic-down";
> +          resets = <&topcrm 18>,
> +            <&topcrm 20>;

Same here.

> +          reset-names = "usb", "hsic";
> +          #phy-cells = <1>;
> +        };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8729cea57c3d..cb50c2e3b4ea 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3878,8 +3878,10 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
>  S:	Odd fixes
>  F:	Documentation/arch/arm/zte/
>  F:	Documentation/devicetree/bindings/arm/zte.yaml
> +F:	Documentation/devicetree/bindings/phy/zte,zx297520v3-usb-phy.yaml
>  F:	arch/arm/boot/dts/zte/
>  F:	arch/arm/mach-zte/
> +F:	include/dt-bindings/phy/phy-zte-zx297520v3-usb.h
>  
>  ARM/ZYNQ ARCHITECTURE
>  M:	Michal Simek <michal.simek@amd.com>
> diff --git a/include/dt-bindings/phy/phy-zte-zx297520v3-usb.h b/include/dt-bindings/phy/phy-zte-zx297520v3-usb.h
> new file mode 100644
> index 000000000000..8a0a3ccbdd63
> --- /dev/null
> +++ b/include/dt-bindings/phy/phy-zte-zx297520v3-usb.h

Filename MUST match compatible.

> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
> +/*
> + * Copyright (C) Stefan Dösinger.
> + */
> +
> +#ifndef __DT_BINDINGS_PHY_USB_ZX297520V3_H
> +#define __DT_BINDINGS_PHY_USB_ZX297520V3_H
> +
> +#define ZX297520V3_USB_PHY	0
> +#define ZX297520V3_HSIC_PHY	1
> +
> +#endif /* __DT_BINDINGS_PHY_USB_ZX297520V3_H */
> 
> -- 
> 2.54.0
>