components/esp_timer/src/esp_timer_impl_common.c (ESP-IDF)

/* * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 */ #include "esp_timer_impl.h" #include "esp_timer.h" #include "esp_err.h" #include "esp_task.h" #include "esp_attr.h" /* Spinlock used to protect access to the hardware registers. */ portMUX_TYPE s_time_update_lock = portMUX_INITIALIZER_UNLOCKED; /* Alarm values to generate interrupt on match * [0] - for ESP_TIMER_TASK alarms, * [1] - for ESP_TIMER_ISR alarms. */ uint64_t timestamp_id[2] = { UINT64_MAX, UINT64_MAX }; void esp_timer_impl_lock(void) { portENTER_CRITICAL(&s_time_update_lock); } void esp_timer_impl_unlock(void) { portEXIT_CRITICAL(&s_time_update_lock); } void esp_timer_private_lock(void) __attribute__((alias("esp_timer_impl_lock"))); void esp_timer_private_unlock(void) __attribute__((alias("esp_timer_impl_unlock"))); void IRAM_ATTR esp_timer_impl_set_alarm(uint64_t timestamp) { esp_timer_impl_set_alarm_id(timestamp, 0); } #ifdef CONFIG_ESP_TIMER_SUPPORTS_ISR_DISPATCH_METHOD void IRAM_ATTR esp_timer_impl_try_to_set_next_alarm(void) { portENTER_CRITICAL_ISR(&s_time_update_lock); unsigned now_alarm_idx; // ISR is called due to this current alarm unsigned next_alarm_idx; // The following alarm after now_alarm_idx if (timestamp_id[0] < timestamp_id[1]) { now_alarm_idx = 0; next_alarm_idx = 1; } else { now_alarm_idx = 1; next_alarm_idx = 0; } if (timestamp_id[next_alarm_idx] != UINT64_MAX) { // The following alarm is valid and can be used. // Remove the current alarm from consideration. esp_timer_impl_set_alarm_id(UINT64_MAX, now_alarm_idx); } else { // There is no the following alarm. // Remove the current alarm from consideration as well. timestamp_id[now_alarm_idx] = UINT64_MAX; } portEXIT_CRITICAL_ISR(&s_time_update_lock); } #endif /* FIXME: This value is safe for 80MHz APB frequency, should be modified to depend on clock frequency. */ uint64_t IRAM_ATTR esp_timer_impl_get_min_period_us(void) { return 50; }