[PATCH] riscv: dts: spacemit: k3: add USB3 port A (DRD) nodes

[Chunyan Zhang]

Hi Troy,

On Mon, 2 Nov 2026 at 14:27, Troy Mitchell <troy at kernel.org> wrote:
>
> Hi Chunyan,
>
> On Fri Oct 30, 2026 at 5:40 PM +0800, Chunyan Zhang wrote:
> > Describe the DWC3 controller and its USB 2.0 PHY for USB3 port A
> > of the K3 SoC.
> >
> > Only the U2 lane is described: Port A's SuperSpeed PHY has no driver
> > yet, so the port runs at high-speed (maximum-speed = "high-speed").
> >
> > Enable USB3 port A with dr_mode = "peripheral", so it can be used as
> > a USB device.
>
> Port A is a Type-C port behind a FUSB301, so please note in the commit
> message that it's device-only until the CC controller is described.
>
> Was this tested with a C-to-C cable? That depends on the FUSB301's
> power-on CC mode, since nothing configures it yet.

Just tested,

On K3:
~ # ls /sys/class/udc
cad00000.usb
~ # cat /sys/class/udc/cad00000.usb/state; echo
configured
~ # cat /sys/class/udc/cad00000.usb/current_speed; echo
high-speed
~ # cat /sys/kernel/config/usb_gadget/g1/idVendor; echo
0x1d6b
~ # cat /sys/kernel/config/usb_gadget/g1/idProduct; echo
0x0104
~ # ls /sys/kernel/config/usb_gadget/g1/functions
acm.usb0           ecm.usb0           mass_storage.usb0
~ #

And the host side sees VID_1D6B:0104 with no error. This is not
guaranteed across all C-to-C host/cable combinations — will note in
the commit message that Port A is device-only until the CC controller
is described, and that C-to-C behavior depends on the FUSB301 power-on
default.

Thanks,
Chunyan