According to the BCM20737 datasheet, it is possible to obtain a reference design for A4WP.
As BCM20737 is part of Cypress, what is the best way to receive support to use BCM20737 for A4WP development?
"The BCM20737 includes support for wireless charging in hardware, software, and firmware. It supports the
protocol for implementing wireless charging solutions based on the specifications written by the Alliance for
Wireless Power (A4WP).
The A4WP protocol is embedded in the BCM20737. Hardware and firmware elements required for wireless
charging are either implemented in the BCM20737 or can be obtained through a Broadcom technical support
Unfortunately, A4WP hardware is not available which will allow you to leverage the A4WP profiles (PTU/PRU) we provide in the WICED Smart SDK. I believe the plan continues to be to provide support for the standard once it is officially ratified by the BT Sig.