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From:   Sven Van Asbroeck <thesven73@gmail.com>
Date:   Mon, 6 Jul 2020 10:53:24 -0400
Message-ID: <CAGngYiXY=0Q3MH+F6+5eeUy8-Wh2yNdUc2=fAQ=dZd3N2YaFow@mail.gmail.com>
Subject: Re: [EXT] Re: [PATCH v5 3/3] ARM: imx6plus: optionally enable
 internal routing of clk_enet_ref
To:     Andy Duan <fugang.duan@nxp.com>
Cc:     Fabio Estevam <festevam@gmail.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        netdev <netdev@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        dl-linux-imx <linux-imx@nxp.com>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Hi Andy,

On Mon, Jul 6, 2020 at 1:30 AM Andy Duan <fugang.duan@nxp.com> wrote:
>
> The clock depends on board design, HW refer guide can describe the clk
> usage in detail and customer select one clk path as their board design.
>

Yes, I agree. But how does a board designer practically describe this
in the devicetree?

Example: mac_gtx -> clk_pad (the default)

Imagine I have a fixed oscillator on the board:

phy_ref_clk: oscillator {
    compatible = "fixed-clock";
    #clock-cells = <0>;
    clock-frequency = <50000000>;
};

How can I now make <&phy_ref_clk> the parent of
<&clks CLK_PAD> ?