diff options
| author |   Lars-Peter Clausen <lars@metafoo.de> | 2019-05-17 16:37:11 +0300 |
|---|---|---|
| committer |   Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2019-05-18 09:40:37 +0100 |
| commit | 0d698a538f8d4827c3209c44db57ca5a5945550e (patch) | |
| tree | 98d0c4eccdaa170a7e8039593c68fa540ba0ed41 /drivers/iio/frequency | |
| parent | iio: dac: ds4422/ds4424 drop of_node check (diff) | |
| download | linux-dev-0d698a538f8d4827c3209c44db57ca5a5945550e.tar.xz linux-dev-0d698a538f8d4827c3209c44db57ca5a5945550e.zip | |
iio: ad9523-1: Improve reported VCO frequency accuracy
To improve the accuracy of the reported VCO frequency perform all
multiplications before divisions. This reduces rounding errors and makes
sure the reported rates are accurate down to the last digit.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/frequency')
| -rw-r--r-- | drivers/iio/frequency/ad9523.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/iio/frequency/ad9523.c b/drivers/iio/frequency/ad9523.c index 9b9eee27176c..ceb1daceeb46 100644 --- a/drivers/iio/frequency/ad9523.c +++ b/drivers/iio/frequency/ad9523.c @@ -862,9 +862,11 @@ static int ad9523_setup(struct iio_dev *indio_dev) if (ret < 0) return ret; - st->vco_freq = (pdata->vcxo_freq * (pdata->pll2_freq_doubler_en ? 2 : 1) - / pdata->pll2_r2_div) * AD9523_PLL2_FB_NDIV(pdata-> - pll2_ndiv_a_cnt, pdata->pll2_ndiv_b_cnt); + st->vco_freq = div_u64((unsigned long long)pdata->vcxo_freq * + (pdata->pll2_freq_doubler_en ? 2 : 1) * + AD9523_PLL2_FB_NDIV(pdata->pll2_ndiv_a_cnt, + pdata->pll2_ndiv_b_cnt), + pdata->pll2_r2_div); ret = ad9523_write(indio_dev, AD9523_PLL2_VCO_CTRL, AD9523_PLL2_VCO_CALIBRATE); |