OCI2C_DATA
msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA);
oc_setreg(i2c, OCI2C_DATA, addr);
oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]);
oc_setreg(i2c, OCI2C_DATA, i2c_8bit_addr_from_msg(i2c->msg));