Zigbee proxying for the ZBT-2 #2

Unlike the ZWA-2, the ZBT-2 has a multitude of possible firmware configurations (with different baudrates) and has both hardware discovery and complex setup config flows in HA Core. This dictates the design of the proxying and forces it to be an outgrowth from generic USB CDC-ACM serial proxying, not a protocol-specific set of API.

A few missing pieces remain. All of this work is done and just needs to be cleaned up and merged into ESPHome PR by PR:

• ESPHome USB serial proxying:

  • ESPHome side: [serial_proxy] Add USB_SERIAL port type and device identity esphome/esphome#19308
  • Serial library side: ESPHome serial proxy mode config and USB identity puddly/serialx#119
  • aioesphomeapi side: USB serial proxying and metadata subscription APIs esphome/aioesphomeapi#1901

• ESPHome USB host product and manufacturer filtering: [usb_host] iManufacturer and iProduct descriptor filters esphome/esphome#19095

• Bugs affecting USB proxying stability:

  • Add a small sacrificial baudrate change for ZBT-2 bootloader NabuCasa/universal-silabs-flasher#147
  • [usb_uart] Fix invalid stop bits and parity enum mappings esphome/esphome#20408
  • Extend the connect timeout for ESPHome URIs NabuCasa/universal-silabs-flasher#148
  • (Not strictly necessary for ZBT-2) Workaround in place for: [esp32-s3] UART baudrate corrupts randomly when changed from low to high (IDFGH-18425) espressif/esp-idf#19198

• SiLabs ASH protocol tap: Zigbee proxying is a firmware-accelerated mode for normal serial proxies and needs a minimal ASH protocol implementation for auto-ACK

  • ESPHome implementation: [ezsp_proxy_tap] Add SiLabs EZSP auto-ACK implementation esphome/esphome#20304
  • Have ZHA require it: Make ESPHome protocol tap mandatory if requested puddly/serialx#138
  • Require ESPHome ASH auto-ACKing when using a serial proxy zigpy/bellows#766

• Full USB descriptor and driver info forwarding from ESPHome

  • [usb_uart] Expose interface_class and port_number esphome/esphome#20659
  • Add interface class and port number to UsbDeviceDescriptor esphome/aioesphomeapi#1941
  • Add port_number to SerialPortInfo puddly/serialx#140
  • (Not strictly necessary for ZBT-2) USB description: WIP

• Full USB proxying support in ESPHome:

  • USB CDC-ACM modem pin control: [usb_uart] Runtime modem pin control for USB and host esphome/esphome#20330
  • USB CDC-ACM hardware flow control: [usb_uart] Implement hardware flow control esphome/esphome#20823

• USB serial proxy integration into HA Core's usb integration: Add support for ESPHome USB serial proxies home-assistant/core#183645

• Convention in HA Core for integrations to opt into identity-based serial ports

  • Add serialx.is_non_unique_serial puddly/serialx#143
  • Add ESPHome USB serial proxy roaming support to ZHA home-assistant/core#187613

  Right now, integrations assume that /dev/serial/by-id/... uniquely identifies a device. With ESPHome serial proxying, a device can roam but technically it's the data encoded within this path: the device's product name, manufacturer name, serial number, etc. This is what allows a ZBT-2 to automatically migrate from a local USB port to a remote, ESPHome USB serial proxy port.