dt-bindings: usb: cdns3: Add cdns,cdnsp compatible string

Introduce a new generic fallback compatible string 'cdns,cdnsp' for
Cadence USBSSP controllers to support hardware configurations where
the Dual-Role Device (DRD) register block is missing or inaccessible.

Following the maintainer's feedback, avoid generic property-like naming
(such as "-no-drd") and use a clean generic fallback. To keep the schema
resource-driven and strictly validated, define a two-string compatible
matrix using an empty schema ({}) wildcard. This allows future vendor
SoC compatibles to be prepended while safely falling back to the 2-resource
USBSSP configuration.

When 'cdns,cdnsp' is matched:
- The 'otg' register and interrupt resources are not required.
- The 'reg' and 'interrupts' properties are restricted to 2 items
  (host and device).
- 'dr_mode' must be explicitly set to either 'host' or 'peripheral'.

The standard 'cdns,usb3' compatible remains unchanged, maintaining
backward compatibility by requiring all 3 resource sets (otg, host, dev).

Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260521-no_drd_config_v9-v9-1-2512cef10104@cadence.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions