OV5640_REG_SC_PLL_CTRL2
ret = ov5640_mod_reg(sensor, OV5640_REG_SC_PLL_CTRL2, 0xff, mult);
ret = ov5640_mod_reg(sensor, OV5640_REG_SC_PLL_CTRL2,
ret = ov5640_read_reg(sensor, OV5640_REG_SC_PLL_CTRL2, &temp1);