Hi Tony,
On Friday 02 Dec 2016 08:53:24 Tony Lindgren wrote:
> * Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> [161202 05:38]:
> > On Thursday 01 Dec 2016 17:18:08 Tony Lindgren wrote:
> >> * Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> [161130 09:58]:
> >>> &usbhsehci {
> >>>
> >>> phys = <0 &hsusb2_phy>;
> >>>
> >>> +
> >>> + #address-cells = <1>;
> >>> + #size-cells = <0>;
> >>> +
> >>> + usb2@2 {
> >>
> >> I think this should be usb1@2 instead of usb2@2? That's because it's
> >> at /sys/bus/usb/devices/1-2 and not at /sys/bus/usb/devices/2-2?
> >>
> >> Or what's the naming standard here?
> >
> > Good question. As far as I know, the node name is irrelevant, only the reg
> > value is important. Maybe we should call it hub@2 ?
>
> Yeah hub sounds good to me, Rob?
>
> Sohow does the kernel know which instance it is if there
> are multiple devices? For example, below is a patch for
> igepv5 (not yet using "hub" naming), note how it has things
> at 3-2 and 3-2.3. So if it also had something at 1-2 and
> 1-2.1, how would we name them?
Every time I have to deal with USB device names I need to look the naming
scheme up. The explanation here might not be 100% accurate.
The first number is the bus number, which more or less identifies a host
controller (and its root hub). That's a dynamically allocated ID that thus
can't be used by DT, but given that DT USB bindings create node as children of
a host controller, we don't need the bus number anyway.
The numbers following the dash identify ports on hubs. 3-2 is thus the device
connected on port 2 of the root hub of bus 3 (which is a hub), and 3-2.3 is
the device connected on port 3 of the hub connected on port 2 of the root hub
of bus 3.
If you had 1-2 and 1-2.1 it would mean that device on port 2 of the root hub
of bus 1 (1-2) is a hub that has device connected on its first port (1-2.1).
> 8< ------------------------
>
> From tony Mon Sep 17 00:00:00 2001
> From: Tony Lindgren <tony@xxxxxxxxxxx>
> Date: Thu, 1 Dec 2016 17:04:50 -0800
> Subject: [PATCH] ARM: dts: omap5-igep0050: Allow bootloader to configure
> USB Ethernet MAC
>
> This is slightly different wiring compared to omap5-uevm or pandaboard:
>
> /sys/bus/usb/devices/3-2 hub
> /sys/bus/usb/devices/3-2.3 7500
>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> arch/arm/boot/dts/omap5-igep0050.dts | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/arch/arm/boot/dts/omap5-igep0050.dts
> b/arch/arm/boot/dts/omap5-igep0050.dts ---
> a/arch/arm/boot/dts/omap5-igep0050.dts
> +++ b/arch/arm/boot/dts/omap5-igep0050.dts
> @@ -19,6 +19,10 @@
> reg = <0x0 0x80000000 0 0x7f000000>; /* 2032 MB */
> };
>
> + aliases {
> + ethernet = ðernet;
> + };
> +
> gpio_keys {
> compatible = "gpio-keys";
> pinctrl-0 = <&power_button_pin>;
> @@ -116,3 +120,20 @@
> OMAP5_IOPAD(0x1ca, PIN_OUTPUT | MUX_MODE6) /*
perslimbus2_clock.gpio5_145
> */
> >;
>
> };
> +
> +&usbhsehci {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + usb3@2 {
> + compatible = "usb424,3503";
> + reg = <2>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + ethernet: usbether@3 {
> + compatible = "usb424,7500";
> + reg = <3>;
> + };
> + };
> +};
--
Regards,
Laurent Pinchart
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