EM28XX_UR_I2C
emdtv_read_multi_1(sc, EM28XX_UR_I2C, addr, datap, len);
emdtv_write_multi_1(sc, EM28XX_UR_I2C + off, addr, datap, len);
emdtv_read_1(sc, EM28XX_UR_I2C, addr);