TCPC_RX_BYTE_CNT
regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, 2);
ret = regmap_raw_read(chip->data.regmap, TCPC_RX_BYTE_CNT, rx_buf, count);