i2c_rdreg
reg->val = i2c_rdreg(sd, reg->reg, reg->size);
return i2c_rdreg(sd, reg, 1);
i2c_wrreg(sd, reg, (i2c_rdreg(sd, reg, 1) & mask) | val, 1);
return i2c_rdreg(sd, reg, 2);
i2c_wrreg(sd, reg, (i2c_rdreg(sd, reg, 2) & mask) | val, 2);
return i2c_rdreg(sd, reg, 4);