/**

* @file power_mgmt.c

* @brief Power management for battery-powered ESP32-S3 CSI nodes.

*

* Uses ESP-IDF's automatic light sleep with WiFi power save mode.

* In light sleep, WiFi maintains association but suspends CSI collection.

* The duty cycle controls how often the device wakes for CSI bursts.

*/

#include "power_mgmt.h"

#include "esp_log.h"

#include "esp_pm.h"

#include "esp_wifi.h"

#include "esp_sleep.h"

#include "esp_timer.h"

static const char *TAG = "power_mgmt";

static uint32_t s_active_ms = 0;

static uint32_t s_sleep_ms = 0;

static uint32_t s_wake_count = 0;

static int64_t s_last_wake = 0;

esp_err_t power_mgmt_init(uint8_t duty_cycle_pct)

{

if (duty_cycle_pct >= 100) {

ESP_LOGI(TAG, "Power management disabled (duty_cycle=100%%)");

return ESP_OK;

}

if (duty_cycle_pct < 10) {

duty_cycle_pct = 10;

ESP_LOGW(TAG, "Duty cycle clamped to 10%% minimum");

}

ESP_LOGI(TAG, "Initializing power management (duty_cycle=%u%%)", duty_cycle_pct);

/* Enable WiFi power save mode (modem sleep). */

esp_err_t err = esp_wifi_set_ps(WIFI_PS_MIN_MODEM);

if (err != ESP_OK) {

ESP_LOGW(TAG, "WiFi power save failed: %s (continuing without PM)",

esp_err_to_name(err));

return err;

}

/* Configure automatic light sleep via power management.

* ESP-IDF will enter light sleep when no tasks are ready to run. */

#if CONFIG_PM_ENABLE

esp_pm_config_t pm_config = {

.max_freq_mhz = 240,

.min_freq_mhz = 80,

.light_sleep_enable = true,

};

err = esp_pm_configure(&pm_config);

if (err != ESP_OK) {

ESP_LOGW(TAG, "PM configure failed: %s", esp_err_to_name(err));

return err;

}

ESP_LOGI(TAG, "Light sleep enabled: max=%dMHz, min=%dMHz",

pm_config.max_freq_mhz, pm_config.min_freq_mhz);

#else

ESP_LOGW(TAG, "CONFIG_PM_ENABLE not set — light sleep unavailable. "

"Enable in menuconfig: Component config → Power Management");

#endif

s_last_wake = esp_timer_get_time();

s_wake_count = 1;

ESP_LOGI(TAG, "Power management initialized (WiFi modem sleep active)");

return ESP_OK;

}

void power_mgmt_stats(uint32_t *active_ms, uint32_t *sleep_ms, uint32_t *wake_count)

{

if (active_ms) *active_ms = s_active_ms;

if (sleep_ms) *sleep_ms = s_sleep_ms;

if (wake_count) *wake_count = s_wake_count;

}