pre_xfer
i2c->bit.pre_xfer = amdgpu_i2c_pre_xfer;
bit->pre_xfer = ast_ddc_algo_bit_data_pre_xfer;
algo->pre_xfer = intel_gpio_pre_xfer;
bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer;
bit->pre_xfer = nvkm_i2c_bus_pre_xfer;
i2c->bit.pre_xfer = pre_xfer;
if (adap->pre_xfer) {
ret = adap->pre_xfer(i2c_adap);
if (adap->pre_xfer) {
ret = adap->pre_xfer(i2c_adap);
int (*pre_xfer) (struct i2c_adapter *);