ch7xxx_readb
if (!ch7xxx_readb(dvo, CH7xxx_REG_VID, &vendor))
if (!ch7xxx_readb(dvo, CH7xxx_REG_DID, &device))
ch7xxx_readb(dvo, CH7xxx_PM, &orig_pm);
ch7xxx_readb(dvo, CH7xxx_CONNECTION_DETECT, &cdet);
ch7xxx_readb(dvo, CH7xxx_IDF, &idf);
ch7xxx_readb(dvo, CH7xxx_PM, &val);
ch7xxx_readb(dvo, i, &val);