Re: [PATCH 2/2] arm64: dts: amlogic: add libretech cottonwood support

From: Neil Armstrong
Date: Tue Oct 03 2023 - 03:36:11 EST


On 02/10/2023 20:57, Jerome Brunet wrote:

On Mon 02 Oct 2023 at 18:45, Neil Armstrong <neil.armstrong@xxxxxxxxxx> wrote:


<snip>

+&usb3_pcie_phy {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ phy-supply = <&vcc_5v>;
+
+ hub: hub@1 {
+ compatible = "usb5e3,626";
+ reg = <1>;
+ reset-gpios = <&gpio GPIOC_7 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+ };

Not sure the PHY is the right place to put the USB HUB,
and it's probable the HUB is connected to both the USB2 and USB3 lines

It is connected to the USB3.0 only

so you should have both USB IDs in DT like it'd done for the Odroid-C4:

/ {
...
/* USB hub supports both USB 2.0 and USB 3.0 root hub */
usb-hub {
dr_mode = "host";
#address-cells = <1>;
#size-cells = <0>;

/* 2.0 hub on port 1 */
hub_2_0: hub@1 {
compatible = "usb2109,2817";
reg = <1>;
peer-hub = <&hub_3_0>;
reset-gpios = <&gpio GPIOH_4 GPIO_ACTIVE_LOW>;
vdd-supply = <&vcc_5v>;
};

/* 3.1 hub on port 4 */
hub_3_0: hub@2 {
compatible = "usb2109,817";
reg = <2>;
peer-hub = <&hub_2_0>;
reset-gpios = <&gpio GPIOH_4 GPIO_ACTIVE_LOW>;
vdd-supply = <&vcc_5v>;
};
};
...
};

if it only has a single USB ID, then it should go under the dwc3 node.

The usb controller is connected to the PHY and what's coming out of the PHY
goes to the hub. It seems logical to hub the hub under it.

Why bypass the PHY ?

The USB bindings the USB devices nodes should be under the controller's node,
not the PHY, see:

Documentation/devicetree/bindings/usb/usb-hcd.yaml
...
patternProperties:
"^.*@[0-9a-f]{1,2}$":
description: The hard wired USB devices
type: object
$ref: /schemas/usb/usb-device.yaml
...
and the example.

Subnodes aren't allowed in the PHY node.

Neil



+};
+
+&usb {
+ status = "okay";
+};

<snip>