mpsl_fem_simple_gpio_interface_config_set gives MPSL assert 122, 29

[SebastianA]

Hi!

I'm trying to decipher the MPSL FEM API documentation and I'm adding code to a bare metal project to initialize the simple gpio interface FEM config.

I'm running (with nrfxlib 2.9.0):

    int32_t err = mpsl_init(&clock_cfg, MPSL_LOW_PRIO_IRQn, mpsl_assert_handler);

    mpsl_fem_simple_gpio_interface_config_t fem_config = {
        .dppi_channels = {
            2, 3, 4,
        },
        .egu_channels = {
            1, 2, 3,
        },
        .egu_instance_no = 20,
        .fem_config = {
            .pa_gain_db = 13,
            .lna_gain_db = 7,
            .pa_time_gap_us = 12,
            .lna_time_gap_us = 24,
        },
        .lna_pin_config = {
            .active_high = false,
            .enable = true,
            .gpio_pin = {
                .p_port = NRF_P1,
                .port_no = 1,
                .port_pin = 10,
            },
            .gpiote_ch_id = 1,
        },
        .pa_pin_config = {
            .active_high = false,
            .enable = true,
            .gpio_pin = {
                .p_port = NRF_P1,
                .port_no = 1,
                .port_pin = 14,
            },
            .gpiote_ch_id = 2,
        },
    };
    
    mpsl_fem_simple_gpio_interface_config_set(&fem_config);

If I remove the call to mpsl_fem_simple_gpio_interface_config_set, this, and the rest of the code, works fine. Adding it causes MPSL to call the assert-handler for file 122, line 29 and not return from mpsl_fem_simple_gpio_interface_config_set.

Is 20 the right value for EGU20? (I've tried 0..3 as well).

We don't use EGU20 for anything else. We also don't use the given DPPI channels (I've tried with others as well) nor the gpio-pins.

Is there some other function that should be called before calling this function?

I've called mpsl_fem_init() before (but its documentation says its not needed if mpsl_init is called). I've called mpsl_fem_power_model_set(NULL); before which didn't help either.

[runsiv]

Hi Sebastian

I suspect the issue is that the 54l15 does not support simple GPIO interface as mentioned here. 

Regards

Runar

[pauleffect]

nRF2220	nRF2220	nRF52, nRF53, nRF54L
nRF21540	nRF21540 GPIO	nRF52, nRF53, nRF54L
nRF21540	nRF21540 GPIO+SPI	nRF52, nRF53
SKY66112-11	Simple GPIO	nRF52, nRF53

Ummm... are you sure? That table is from the link you provided. Though it probably got updated one day after your post (per Murphy's law).

[SebastianA]

The last line is for the simple gpio FEM driver that I tried to use. Its not supported on the nRF54L.

Too bad there is no radio event notification anymore. Then all FEMs could be supported at the cost of some extra energy.

[runsiv]

There should be a radio notification event now ref https://docs.nordicsemi.com/bundle/ncs-2.9.0/page/nrf/libraries/bluetooth/radio_notification_conn_cb.html 

It was added last year from what I recall

[SebastianA]

Aha, thanks! I looked quickly at it and thought it was only per BT connection, not per radio event.

[runsiv]

Happy to help!

Regards

Runar