usb: core: Set connect_type of ports based on DT node

usb: core: Set connect_type of ports based on DT node

When a USB hub is described in DT, such as any device that matches the
onboard-hub driver, the connect_type is set to "unknown" or
USB_PORT_CONNECT_TYPE_UNKNOWN. This makes any device plugged into that
USB port report their 'removable' device attribute as "unknown".
ChromeOS userspace would like to know if the USB device is actually
removable or not so that security policies can be applied. Improve the
connect_type attribute for ports, and in turn the removable attribute
for USB devices, by looking for child devices with a reg property or an
OF graph when the device is described in DT.

If the graph exists, endpoints that are connected to a remote node must
be something like a usb-{a,b,c}-connector compatible node, or an
intermediate node like a redriver, and not a hardwired USB device on the
board. Set the connect_type to USB_PORT_CONNECT_TYPE_HOT_PLUG in this
case because the device is going to be plugged in. Set the connect_type
to USB_PORT_CONNECT_TYPE_HARD_WIRED if there's a child node for the port
like 'device@2' for port2. Set the connect_type to USB_PORT_NOT_USED if
there isn't an endpoint or child node corresponding to the port number.

To make sure things don't change, only set the port to not used if
there are child nodes. This way an onboard hub connect_type doesn't
change until ports are added or child nodes are added to describe
hardwired devices. It's assumed that all ports or no ports will be
described for a device.

Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: Pin-yen Lin <treapking@chromium.org>
Cc: maciek swiech <drmasquatch@google.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20240223005823.3074029-3-swboyd@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>