How to use enable the FIQ with the ARM timer on rpi zero in my driver?

[s.achterop at rug.nl]

> When using:
> 
>   ret = claim_fiq(&bat_fh);
>   set_fiq_handler(&batradio_handler, &batradio_handler_end - &batradio_handler);
>   set_fiq_regs(&regs);
>   enable_fiq(x);
> 

 From driver/irqchip/irq-bcm2835.c I infer that I probably will need to use the devicetree somehow,
But what compatible string should I use when creating the driver.
I tried several things and really am at a loss here,

    thanks in advance,
       Sietse