wf_fcu_write_reg
rc = wf_fcu_write_reg(pv, 0x10 + (fan->id * 2), buf, 2);
rc = wf_fcu_write_reg(pv, 0x30 + (fan->id * 2), buf, 1);
rc = wf_fcu_write_reg(pv, 0xe, &buf, 1);
rc = wf_fcu_write_reg(pv, 0x2e, &buf, 1);