pm_system_suspend() is flagged as warning: implicit declaration of function 'pm_system_suspend' [-Wimplicit-function-declaration] even when CONFIG_PM_DEVICE_SYSTEM_MANAGED = y. https://docs.zephyrproject.org/latest/services/pm/device.html

[epolicar]

[runsiv]

Hi Edgar

Which version of NCS are you using? 

Regards

Runar

[epolicar]

My version is Zephyr v3.7.99, NCS v2.9.0

[runsiv]

Thanks. As far as I know the 52 series only support the power state system on and system off as mention here. Regarding pm_system_suspend() that is not a function you should call, but it is called by the kernel to inform listeners if enabled by CONFIG_PM. You can read more about the Zephyr power management system here.

Regards

Runar

[epolicar]

I have abandoned pm_system_suspend() and switched to pm_policy_next_state. Below is my code for this including PM notifiers:

// Custom power management policy

const struct pm_state_info *pm_policy_next_state(uint8_t cpu, int32_t ticks)

{

    static const struct pm_state_info suspend_state = {

        .state = PM_STATE_SUSPEND_TO_RAM,

        .substate_id = 0,

        .min_residency_us = 1000,

        .exit_latency_us = 500,

    };

    if (!is_active_mode && !advertising_active && !ble_active) {

        return &suspend_state;

    }

    return NULL;

}

static void on_pm_entry(enum pm_state state)

{

    if (state == PM_STATE_SUSPEND_TO_RAM) {

        DEBUG_PRINT("Entering suspend state...\n");

    }

}

static void on_pm_exit(enum pm_state state)

{

    if (state == PM_STATE_SUSPEND_TO_RAM) {

        resume_peripherals();

        DEBUG_PRINT("Exiting suspend state...\n");

    }

}

static struct pm_notifier pm_cb = {

    .state_entry = on_pm_entry,

    .state_exit  = on_pm_exit,

};

I have this function for debugging:

void show_next_pm_state(void)

{

    const struct pm_state_info *info = pm_policy_next_state(0, INT32_MAX);

    if (info) {

        printk("System would enter sleep state: %d\n", info->state);

    } else {

        printk("System would stay active.\n");

    }

}


Then in my main(), I have this:
int main(void) {

// ... some init codes...

    pm_notifier_register(&pm_cb);

// ... more codes ..

    /* Main loop - sleep forever until interrupted */

    while (1) {

    //  k_sleep(K_FOREVER);  // Sleep indefinitely

        show_next_pm_state();

        k_sleep(K_SECONDS(60));  // Sleep for 60 second (temporary for testing)

    }

    return 0;

}

I have SPI, UART, I2C, ADC, PWM, and Bluetooth suspended or disabled, but my system just wont go to sleep. I would appreciate very much if you or anyone can tell me what could be wrong?

Regards,

[epolicar]

Hi runsive,

I would appreciate feed back from you regarding my recent message.

Regards,