iio: adc: stm32-dfsdm: improve sampling frequency accuracy

Browse source

The sample frequency is driven using the oversampling ratio depending
on the SPI bus frequency.
Currently, oversampling ratio is computed by an entire division:
- spi_freq / sample_freq. This may result in inaccurate value.
Using DIV_ROUND_CLOSEST improves resulting sample frequency, which is
useful for audio that requests fixed rates (such as: 8, 16 or 32 kHz).
BTW, introduce new routine to re-factor sample frequency setting, and
move frequency accuracy message from warning to debug level.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

...

This commit is contained in:

Fabrice Gasnier 2019-03-25 15:24:01 +01:00 • committed by Jonathan Cameron

parent 65500c53aa

commit 9f57110d2e

1 changed files with 30 additions and 26 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

56

drivers/iio/adc/stm32-dfsdm-adc.c

View file