XTAL_FREQ
return DIV_ROUND_DOWN_ULL(pll_freq, XTAL_FREQ);
unsigned long long parent_freq = XTAL_FREQ;
ir->duty_cycle * XTAL_FREQ / 1000, ir->carrier);
(100 - ir->duty_cycle) * XTAL_FREQ / 1000, ir->carrier);
l = DIV_ROUND_CLOSEST((XTAL_FREQ / 1000) * txbuf[i], 40000);