systimer: support etm event

components/esp_timer/include/esp_timer.h

@@ -34,6 +34,7 @@
 #include <stdio.h>
 #include <stdbool.h>
 #include "esp_err.h"
+#include "esp_etm.h"
 #include "sdkconfig.h"
 
 #ifdef __cplusplus
@@ -311,6 +312,21 @@ void esp_timer_isr_dispatch_need_yield(void);
  */
 bool esp_timer_is_active(esp_timer_handle_t timer);
 
+/**
+ * @brief Get the ETM event handle of esp_timer underlying alarm event
+ *
+ * @note The created ETM event object can be deleted later by calling `esp_etm_del_event`
+ *
+ * @note The ETM event is generated by the underlying hardware -- systimer,
+ *       therefore, if the esp_timer is not clocked by systimer, then no ETM event will be generated.
+ *
+ * @param[out] out_event Returned ETM event handle
+ * @return
+ *      - ESP_OK Success
+ *      - ESP_ERR_INVALID_ARG Parameter error
+ */
+esp_err_t esp_timer_new_etm_alarm_event(esp_etm_event_handle_t *out_event);
+
 #ifdef __cplusplus
 }
 #endif