CMD_SET_FREQ
iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
case CMD_SET_FREQ:
ret = airspy_ctrl_msg(s, CMD_SET_FREQ, 0, 0, buf, 4);
case CMD_SET_FREQ:
ret = hackrf_ctrl_msg(dev, CMD_SET_FREQ, 0, 0, buf, 8);