From eca949800d2dd761bc0c73b793e4e9ad4a997469 Mon Sep 17 00:00:00 2001 From: Arnaud Pouliquen Date: Wed, 10 Jan 2018 11:13:12 +0100 Subject: IIO: ADC: add stm32 DFSDM support for PDM microphone This code offers a way to handle PDM audio microphones in ASOC framework. Audio driver should use consumer API. A specific management is implemented for DMA, with a callback, to allows to handle audio buffers efficiently. Signed-off-by: Arnaud Pouliquen Reviewed-by: Jonathan Cameron Signed-off-by: Mark Brown --- Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 (limited to 'Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32') diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 new file mode 100644 index 000000000000..da9822309f07 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 @@ -0,0 +1,16 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_voltage_spi_clk_freq +KernelVersion: 4.14 +Contact: arnaud.pouliquen@st.com +Description: + For audio purpose only. + Used by audio driver to set/get the spi input frequency. + This is mandatory if DFSDM is slave on SPI bus, to + provide information on the SPI clock frequency during runtime + Notice that the SPI frequency should be a multiple of sample + frequency to ensure the precision. + if DFSDM input is SPI master + Reading SPI clkout frequency, + error on writing + If DFSDM input is SPI Slave: + Reading returns value previously set. + Writing value before starting conversions. \ No newline at end of file -- cgit v1.2.3