Hi, My name is Cristian and I'm working on bringing up a USB Type-C Port Controller (TCPC) without Power Delivery support which is intended to work with USB 2.0 Host/Device. The IP is integrated into one of Microchip's SoCs, it is memory-mapped and it was designed based on USB Type-C Cable and Connector specification revision 1.2. In brief, it has support for detecting the threshold voltages on CC1, CC2 lines, control of the current source (Ip), and pull-down resistors (Rd). The management of the controller is to be implemented in software (it is not autonomous). Having in mind that the controller uses proprietary registers, I chose to implement it using TCPM directly and skip the TCPC Interface. For the beginning, I would like to enable simple use cases like the ones described in Connection State Diagram: Source and Connection State Diagram: Sink from USB Type-C Cable and Connector Specification. Some of the problems that I encountered until now are: 1. tcpm_register_port() fails if set_pd_rx(), pd_transmit() or set_vconn() functions are missing. 2. the port capabilities are specified in the connector DT bindings only through PDOs, even though PDOs are specific to PD mode. 3. once I was able to start the TCPM state machine, it called pd_transmit() in the process to negotiate the capabilities. For my case I used a dummy function just to be able to register the port. Please let me know what you think and if you have any advice. Am I going in the right direction or is there a better way to implement this? Kind regards, Cristian
