MXGEFW_CMD_I2C_BYTE
err = mxge_send_cmd(sc, MXGEFW_CMD_I2C_BYTE, &cmd);
err = mxge_send_cmd(sc, MXGEFW_CMD_I2C_BYTE, &cmd);
err = mxge_send_cmd(sc, MXGEFW_CMD_I2C_BYTE, &cmd);
err = mxge_send_cmd(sc, MXGEFW_CMD_I2C_BYTE, &cmd);