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Date:   Mon, 09 Sep 2019 17:37:33 +0100
Message-ID: <864l1ls9wy.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Neil Armstrong <narmstrong@baylibre.com>
Cc:     khilman@baylibre.com, bhelgaas@google.com,
        lorenzo.pieralisi@arm.com, yue.wang@Amlogic.com, kishon@ti.com,
        repk@triplefau.lt, linux-amlogic@lists.infradead.org,
        linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/6] arm64: dts: khadas-vim3: add commented support for PCIe
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        <1567950178-4466-7-git-send-email-narmstrong@baylibre.com>
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On Sun, 08 Sep 2019 14:42:58 +0100,
Neil Armstrong <narmstrong@baylibre.com> wrote:
> 
> The VIM3 on-board  MCU can mux the PCIe/USB3.0 shared differential
> lines using a FUSB340TMX USB 3.1 SuperSpeed Data Switch between
> an USB3.0 Type A connector and a M.2 Key M slot.
> The PHY driving these differential lines is shared between
> the USB3.0 controller and the PCIe Controller, thus only
> a single controller can use it.
> 
> The needed DT configuration when the MCU is configured to mux
> the PCIe/USB3.0 differential lines to the M.2 Key M slot is
> added commented and may uncommented to disable USB3.0 from the
> USB Complex and enable the PCIe controller.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  .../amlogic/meson-g12b-a311d-khadas-vim3.dts  | 22 +++++++++++++++++++
>  .../amlogic/meson-g12b-s922x-khadas-vim3.dts  | 22 +++++++++++++++++++
>  .../boot/dts/amlogic/meson-khadas-vim3.dtsi   |  4 ++++
>  .../dts/amlogic/meson-sm1-khadas-vim3l.dts    | 22 +++++++++++++++++++
>  4 files changed, 70 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
> index 3a6a1e0c1e32..0577b1435cbb 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
> @@ -14,3 +14,25 @@
>  / {
>  	compatible = "khadas,vim3", "amlogic,a311d", "amlogic,g12b";
>  };
> +
> +/*
> + * The VIM3 on-board  MCU can mux the PCIe/USB3.0 shared differential
> + * lines using a FUSB340TMX USB 3.1 SuperSpeed Data Switch between
> + * an USB3.0 Type A connector and a M.2 Key M slot.
> + * The PHY driving these differential lines is shared between
> + * the USB3.0 controller and the PCIe Controller, thus only
> + * a single controller can use it.
> + * If the MCU is configured to mux the PCIe/USB3.0 differential lines
> + * to the M.2 Key M slot, uncomment the following block to disable
> + * USB3.0 from the USB Complex and enable the PCIe controller.
> + */
> +/*
> +&pcie {
> +	status = "okay";
> +};
> +
> +&usb {
> +	phys = <&usb2_phy0>, <&usb2_phy1>;
> +	phy-names = "usb2-phy0", "usb2-phy1";
> +};
> + */

Although you can't do much more than this here, I'd expect firmware on
the machine to provide the DT that matches its configuration. Is it
the way it actually works? Or is the user actually expected to edit
this file?

Thanks,

	M.

-- 
Jazz is not dead, it just smells funny.