[opentherm] Fix ESP-IDF build by re-enabling legacy driver component (#13732)

esphome/components/opentherm/__init__.py

@@ -4,8 +4,10 @@ from typing import Any
 from esphome import automation, pins
 import esphome.codegen as cg
 from esphome.components import sensor
+from esphome.components.esp32 import include_builtin_idf_component
 import esphome.config_validation as cv
 from esphome.const import CONF_ID, CONF_TRIGGER_ID, PLATFORM_ESP32, PLATFORM_ESP8266
+from esphome.core import CORE
 
 from . import const, generate, schema, validate
 
@@ -83,6 +85,12 @@ CONFIG_SCHEMA = cv.All(
 
 
 async def to_code(config: dict[str, Any]) -> None:
+    if CORE.is_esp32:
+        # Re-enable ESP-IDF's legacy driver component (excluded by default to save compile time)
+        # Provides driver/timer.h header for hardware timer API
+        # TODO: Remove this once opentherm migrates to GPTimer API (driver/gptimer.h)
+        include_builtin_idf_component("driver")
+
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
 

esphome/components/opentherm/opentherm.cpp

@@ -8,6 +8,8 @@
 #include "opentherm.h"
 #include "esphome/core/helpers.h"
 #include <cinttypes>
+// TODO: Migrate from legacy timer API (driver/timer.h) to GPTimer API (driver/gptimer.h)
+// The legacy timer API is deprecated in ESP-IDF 5.x. See opentherm.h for details.
 #ifdef USE_ESP32
 #include "driver/timer.h"
 #include "esp_err.h"

esphome/components/opentherm/opentherm.h

@@ -12,6 +12,10 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
+// TODO: Migrate from legacy timer API (driver/timer.h) to GPTimer API (driver/gptimer.h)
+// The legacy timer API is deprecated in ESP-IDF 5.x. Migration would allow removing the
+// "driver" IDF component dependency. See:
+// https://docs.espressif.com/projects/esp-idf/en/latest/esp32/migration-guides/release-5.x/5.0/peripherals.html#id4
 #ifdef USE_ESP32
 #include "driver/timer.h"
 #endif