_idtcm_adjfine
err = _idtcm_adjfine(channel, channel->current_freq_scaled_ppm);
err = _idtcm_adjfine(channel, delta_ppm);
err = _idtcm_adjfine(channel, scaled_ppm);
static int _idtcm_adjfine(struct idtcm_channel *channel, long scaled_ppm);