Thanks for posting your question!

You could check your IRQ- pin’s level when entering your interrupt message function in order to check if a rising or falling edge is detected. In case your pin’s level was initially low and when entering your message function it became high then a rising edge was detected. If your pin was initially high and also became low then a falling edge was detected. You could read your pin level by accessing the register shown in the picture below.

For example, if your IRQ pin is P110, you could check its level in the interrupt message function like this:
R_PORT1->PIDR_b. PIDR10 and check if it’s 1 (HIGH) or 0 (LOW).

Another way is by using the already given API
1.fsp_err_tR_IOPORT_PinRead(ioport_ctrl_t * constp_ctrl,bsp_io_port_pin_t pin,bsp_io_level_t *p_pin_value);

Kind Regards,
Alex