EM28XX_R23_UOFFSET
{EM28XX_R23_UOFFSET, 0x00, 0xff, 0},
ret = em28xx_write_reg(dev, EM28XX_R23_UOFFSET, ctrl->val);
em28xx_write_reg(dev, EM28XX_R23_UOFFSET, BLUE_BALANCE_DEFAULT);