Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32

   1 What:           /sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq
   2 KernelVersion:  4.14
   3 Contact:        arnaud.pouliquen@st.com
   4 Description:
   5                 For audio purpose only.
   6
   7                 Used by audio driver to set/get the spi input frequency.
   8
   9                 This is mandatory if DFSDM is slave on SPI bus, to
  10                 provide information on the SPI clock frequency during runtime
  11                 Notice that the SPI frequency should be a multiple of sample
  12                 frequency to ensure the precision.
  13
  14                 if DFSDM input is SPI master:
  15
  16                         Reading  SPI clkout frequency,
  17                         error on writing
  18
  19                 If DFSDM input is SPI Slave:
  20
  21                         Reading returns value previously set.
  22                         Writing value before starting conversions.