Re: [PATCH v3 2/5] dt-bindings: Add a binding for Mediatek xHCI host controller

Mark Rutland
2015-07-22T14:22:39Z

On Wed, Jul 22, 2015 at 03:05:42PM +0100, Chunfeng Yun wrote:
> add a DT binding documentation of xHCI host controller for the
> MT8173 SoC from Mediatek.
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> .../devicetree/bindings/usb/mt8173-xhci.txt | 50 ++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/usb/mt8173-xhci.txt
>
> diff --git a/Documentation/devicetree/bindings/usb/mt8173-xhci.txt b/Documentation/devicetree/bindings/usb/mt8173-xhci.txt
> new file mode 100644
> index 0000000..444494d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/mt8173-xhci.txt
> @@ -0,0 +1,50 @@
> +MT65XX xhci
> +
> +The device node for Mediatek SOC usb3.0 host controller
> +
> +Required properties:
> + - compatible : supports "mediatek,mt8173-xhci"
> + - reg : Offset and length of registers

Your example has multiple reg entries.

Please list what each entry is, and the order you expect them in.

> + - interrupts : Interrupt mode, number and trigger mode
> + - power-domains: to enable usb's mtcmos
> + - vusb33-supply: regulator of usb avdd3.3v
> + - clocks : must support all clocks that xhci needs
> + - clock-names: should be "sys_mac" for sys and mac clocks, and
> + "wakeup_deb_p0", "wakeup_deb_p1" for wakeup debounce control
> + clocks
> + - phys : the phys that xhci will bind, currently supports up to two
> + phys, so phy index should not greater than one.
> + - phy-names : should be "phy-X" format, X equals to 0 or 1

This seems somewhat pointless.

> + - usb3-lpm-capable: supports USB3 LPM
> + - mediatek,usb-wakeup: to access usb wakeup control register

What exactly does this property imply?

> + - mediatek,wakeup-src: 1: ip sleep wakeup mode; 2: line state wakeup
> + mode; others means don't enable wakeup source of usb

This sounds like configuration rather than a hardware property. Why do
you think this needs to be in the DT?

> + - mediatek,u2port-num: the number should not greater than the number
> + of phys

What exactly does this property imply?

Mark.

> +
> +Optional properties:
> + - vbus-supply : reference to the VBUS regulator;
> +
> +Example:
> +usb: usb30@11270000 {
> + compatible = "mediatek,mt8173-xhci";
> + reg = <0 0x11270000 0 0x4000>,
> + <0 0x11280000 0 0x0800>;
> + interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_LOW>;
> + power-domains = <&scpsys MT8173_POWER_DOMAIN_USB>;
> + clocks = <&topckgen CLK_TOP_USB30_SEL>,
> + <&pericfg CLK_PERI_USB0>,
> + <&pericfg CLK_PERI_USB1>;
> + clock-names = "sys_mac",
> + "wakeup_deb_p0",
> + "wakeup_deb_p1";
> + phys = <&u3phy 0>, <&u3phy 1>;
> + phy-names = "phy-0", "phy-1";
> + vusb33-supply = <&mt6397_vusb_reg>;
> + vbus-supply = <&usb_p1_vbus>;
> + usb3-lpm-capable;
> + mediatek,usb-wakeup = <&pericfg>;
> + mediatek,wakeup-src = <1>;
> + mediatek,u2port-num = <2>;
> + status = "okay";
> +};
> --
> 1.8.1.1.dirty
>