OV5640_REG_SC_PLL_CTRL0
ret = ov5640_mod_reg(sensor, OV5640_REG_SC_PLL_CTRL0, 0x0f, bit_div);
ret = ov5640_mod_reg(sensor, OV5640_REG_SC_PLL_CTRL0,
ret = ov5640_read_reg(sensor, OV5640_REG_SC_PLL_CTRL0, &temp1);