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References: <20220412065611.8930-1-dylan_hung@aspeedtech.com> <20220412065611.8930-2-dylan_hung@aspeedtech.com>
In-Reply-To: <20220412065611.8930-2-dylan_hung@aspeedtech.com>
From:   Joel Stanley <joel@jms.id.au>
Date:   Wed, 13 Apr 2022 02:34:08 +0000
Message-ID: <CACPK8Xd0gh5pDafP3ysu7odhnP=YPNSYPV9u36CEoMPDtQxEJw@mail.gmail.com>
Subject: Re: [PATCH v4 1/3] dt-bindings: net: add reset property for aspeed,
 ast2600-mdio binding
To:     Dylan Hung <dylan_hung@aspeedtech.com>
Cc:     Rob Herring <robh+dt@kernel.org>, Andrew Jeffery <andrew@aj.id.au>,
        Andrew Lunn <andrew@lunn.ch>, hkallweit1@gmail.com,
        Russell King <linux@armlinux.org.uk>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, pabeni@redhat.com,
        Philipp Zabel <p.zabel@pengutronix.de>,
        devicetree <devicetree@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-aspeed <linux-aspeed@lists.ozlabs.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Networking <netdev@vger.kernel.org>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        BMC-SW <BMC-SW@aspeedtech.com>,
        Krzysztof Kozlowski <krzk@kernel.org>
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On Tue, 12 Apr 2022 at 06:55, Dylan Hung <dylan_hung@aspeedtech.com> wrote:
>
> The AST2600 MDIO bus controller has a reset control bit and must be
> deasserted before manipulating the MDIO controller. By default, the
> hardware asserts the reset so the driver only need to deassert it.
>
> Regarding to the old DT blobs which don't have reset property in them,
> the reset deassertion is usually done by the bootloader so the reset
> property is optional to work with them.
>
> Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
> ---
>  .../devicetree/bindings/net/aspeed,ast2600-mdio.yaml         | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml b/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
> index 1c88820cbcdf..1174c14898e1 100644
> --- a/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
> +++ b/Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml
> @@ -20,10 +20,14 @@ allOf:
>  properties:
>    compatible:
>      const: aspeed,ast2600-mdio
> +
>    reg:
>      maxItems: 1
>      description: The register range of the MDIO controller instance
>
> +  resets:
> +    maxItems: 1
> +
>  required:
>    - compatible
>    - reg
> @@ -39,6 +43,7 @@ examples:
>              reg = <0x1e650000 0x8>;
>              #address-cells = <1>;
>              #size-cells = <0>;
> +            resets = <&syscon ASPEED_RESET_MII>;

You will need to include the definition for ASPEED_RESET_MII at the
start of the example:

#include <dt-bindings/clock/ast2600-clock.h>

You can test the bindings example by doing this:

pip install dtschema

make dt_binding_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/net/aspeed,ast2600-mdio.yaml

Cheers,

Joel

>
>              ethphy0: ethernet-phy@0 {
>                      compatible = "ethernet-phy-ieee802.3-c22";
> --
> 2.25.1
>