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Date:   Wed, 11 Sep 2019 13:50:36 +0100
From:   Andrew Murray <andrew.murray@arm.com>
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, maz@kernel.org,
        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
Message-ID: <20190911125035.GU9720@e119886-lin.cambridge.arm.com>
References: <1567950178-4466-1-git-send-email-narmstrong@baylibre.com>
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On Sun, Sep 08, 2019 at 01:42:58PM +0000, Neil Armstrong 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

*and may be*

> 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";
> +};

I assume there is no way other way to determine from the hardware which way
the mux is set?

Otherwise phy_g12a_usb3_pcie_xlate could determine the hardware mode, and
reject the phy instance with the wrong mode. Thus resulting in either the
PCI or USB to fail their probe. And avoiding the need to modify the DT on
boot.

Thanks,

Andrew Murray

> + */
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-s922x-khadas-vim3.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-s922x-khadas-vim3.dts
> index b73deb282120..1ef5c2f04f67 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-s922x-khadas-vim3.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-s922x-khadas-vim3.dts
> @@ -14,3 +14,25 @@
>  / {
>  	compatible = "khadas,vim3", "amlogic,s922x", "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";
> +};
> + */
> diff --git a/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi b/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
> index 8647da7d6609..eac5720dc15f 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-khadas-vim3.dtsi
> @@ -246,6 +246,10 @@
>  	linux,rc-map-name = "rc-khadas";
>  };
>  
> +&pcie {
> +	reset-gpios = <&gpio GPIOA_8 GPIO_ACTIVE_LOW>;
> +};
> +
>  &pwm_ef {
>          status = "okay";
>          pinctrl-0 = <&pwm_e_pins>;
> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1-khadas-vim3l.dts b/arch/arm64/boot/dts/amlogic/meson-sm1-khadas-vim3l.dts
> index 5233bd7cacfb..d9c7cbedce53 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-sm1-khadas-vim3l.dts
> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1-khadas-vim3l.dts
> @@ -68,3 +68,25 @@
>  	clock-names = "clkin1";
>  	status = "okay";
>  };
> +
> +/*
> + * 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";
> +};
> + */
> -- 
> 2.17.1
>