SMB_CORE_CTRL_ESO
regval = SMB_CORE_CTRL_FW_ACK | SMB_CORE_CTRL_ESO | SMB_CORE_CTRL_ACK;
regval = SMB_CORE_CTRL_ESO | SMB_CORE_CTRL_ACK;
writeb(SMB_CORE_CTRL_ESO, i2c->i2c_base + SMB_CORE_CTRL_REG_OFF);