[serial_proxy] Make port mode protocol-neutral

Rename SERIAL_PROXY_MODE_EZSP_ASH to SERIAL_PROXY_MODE_PROTOCOL so the
serial_proxy API surface carries no protocol-specific names. The mode now
means "the port's tap is active"; which protocol the tap speaks is a
property of the device configuration, discoverable from the tap
component's own API surface. Future protocol taps need no serial_proxy
or API changes.

esphome/components/api/api.proto

@@ -2845,12 +2845,15 @@ message SerialProxyRequestResponse {
   string error_message = 4;            // Additional detail on failure (optional)
 }
 
-// How a port treats the bytes passing through it. RAW is a plain byte pipe; EZSP_ASH lets
-// a protocol-aware tap acknowledge NCP frames and read network metadata. A client that is
-// about to flash firmware selects RAW first, which definitively disables that injection.
+// How a port treats the bytes passing through it. RAW is a plain byte pipe; PROTOCOL
+// activates the port's protocol-aware tap (if one is configured), letting it observe
+// traffic and inject protocol bytes such as acknowledgements. Which protocol the tap
+// speaks is a property of the device configuration, discoverable from the tap
+// component's own API surface. A client that is about to flash firmware selects RAW
+// first, which definitively disables that injection.
 enum SerialProxyMode {
   SERIAL_PROXY_MODE_RAW = 0;
-  SERIAL_PROXY_MODE_EZSP_ASH = 1;
+  SERIAL_PROXY_MODE_PROTOCOL = 1;
 }
 
 message SerialProxySetModeRequest {

esphome/components/api/api_pb2.h

@@ -368,7 +368,7 @@ enum SerialProxyStatus : uint32_t {
 };
 enum SerialProxyMode : uint32_t {
   SERIAL_PROXY_MODE_RAW = 0,
-  SERIAL_PROXY_MODE_EZSP_ASH = 1,
+  SERIAL_PROXY_MODE_PROTOCOL = 1,
 };
 #endif
 #ifdef USE_ZIGBEE_PROXY

esphome/components/api/api_pb2_dump.cpp

@@ -882,8 +882,8 @@ template<> const char *proto_enum_to_string<enums::SerialProxyMode>(enums::Seria
   switch (value) {
     case enums::SERIAL_PROXY_MODE_RAW:
       return ESPHOME_PSTR("SERIAL_PROXY_MODE_RAW");
-    case enums::SERIAL_PROXY_MODE_EZSP_ASH:
-      return ESPHOME_PSTR("SERIAL_PROXY_MODE_EZSP_ASH");
+    case enums::SERIAL_PROXY_MODE_PROTOCOL:
+      return ESPHOME_PSTR("SERIAL_PROXY_MODE_PROTOCOL");
     default:
       return ESPHOME_PSTR("UNKNOWN");
   }

esphome/components/serial_proxy/__init__.py

@@ -41,12 +41,13 @@ SERIAL_PROXY_PORT_TYPES = {
 }
 
 SerialProxyMode = api_enums_ns.enum("SerialProxyMode")
-# The mode a port starts in. `raw` is a plain byte pipe; `ezsp_ash` lets a tap
-# acknowledge NCP frames and read network metadata off the wire. Clients may change
-# it at runtime, so this only decides what the device boots into.
+# The mode a port starts in. `raw` is a plain byte pipe; `protocol` activates the
+# port's tap (if one is configured), letting it observe traffic and inject protocol
+# bytes such as acknowledgements. Clients may change it at runtime, so this only
+# decides what the device boots into.
 SERIAL_PROXY_MODES = {
     "RAW": SerialProxyMode.SERIAL_PROXY_MODE_RAW,
-    "EZSP_ASH": SerialProxyMode.SERIAL_PROXY_MODE_EZSP_ASH,
+    "PROTOCOL": SerialProxyMode.SERIAL_PROXY_MODE_PROTOCOL,
 }
 
 CONF_DTR_PIN = "dtr_pin"

esphome/components/serial_proxy/serial_proxy.cpp

@@ -130,7 +130,7 @@ bool SerialProxy::tap_observing_() const {
   // Otherwise the mode decides. RAW must be inert: a client that flips to RAW before
   // flashing firmware is entitled to a byte pipe with nothing injecting protocol bytes
   // into it, and "the tap turned out not to recognise the stream" is not good enough.
-  return this->mode_ == api::enums::SERIAL_PROXY_MODE_EZSP_ASH;
+  return this->mode_ == api::enums::SERIAL_PROXY_MODE_PROTOCOL;
 }
 
 void SerialProxy::tap_pump() {
@@ -156,7 +156,7 @@ void SerialProxy::dump_config() {
       this->port_type_ == api::enums::SERIAL_PROXY_PORT_TYPE_RS485   ? LOG_STR_LITERAL("RS485")
       : this->port_type_ == api::enums::SERIAL_PROXY_PORT_TYPE_RS232 ? LOG_STR_LITERAL("RS232")
                                                                      : LOG_STR_LITERAL("TTL"),
-      this->mode_ == api::enums::SERIAL_PROXY_MODE_EZSP_ASH ? LOG_STR_LITERAL("EZSP_ASH") : LOG_STR_LITERAL("RAW"),
+      this->mode_ == api::enums::SERIAL_PROXY_MODE_PROTOCOL ? LOG_STR_LITERAL("PROTOCOL") : LOG_STR_LITERAL("RAW"),
       this->rts_pin_ != nullptr ? LOG_STR_LITERAL("configured") : LOG_STR_LITERAL("not configured"),
       this->dtr_pin_ != nullptr ? LOG_STR_LITERAL("configured") : LOG_STR_LITERAL("not configured"));
 }
@@ -239,7 +239,7 @@ void SerialProxy::set_mode(api::APIConnection *api_connection, api::enums::Seria
   }
 #endif
   ESP_LOGD(TAG, "Serial proxy [%" PRIu32 "] mode set to %s", this->instance_index_,
-           mode == api::enums::SERIAL_PROXY_MODE_EZSP_ASH ? "EZSP_ASH" : "RAW");
+           mode == api::enums::SERIAL_PROXY_MODE_PROTOCOL ? "PROTOCOL" : "RAW");
   const bool leaving_protocol_mode =
       this->mode_ != api::enums::SERIAL_PROXY_MODE_RAW && mode == api::enums::SERIAL_PROXY_MODE_RAW;
   this->mode_ = mode;

tests/components/zigbee_proxy/common.yaml

@@ -20,4 +20,4 @@ serial_proxy:
     uart_id: zigbee_uart
     name: Zigbee
     port_type: TTL
-    mode: ezsp_ash
+    mode: protocol

tests/components/zigbee_proxy/test-usb.esp32-s3-idf.yaml

@@ -22,7 +22,7 @@ serial_proxy:
     uart_id: zigbee_usb_channel
     name: Zigbee
     port_type: TTL
-    mode: ezsp_ash
+    mode: protocol
 
 zigbee_proxy:
   serial_proxy_id: zigbee_usb_serial