[Feature] add GA346 baseline version

Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32 b/src/kernel/linux/v4.19/Documentation/ABI/testing/sysfs-bus-iio-dfsdm-adc-stm32
new file mode 100644
index 0000000..da98223
--- /dev/null
+++ b/src/kernel/linux/v4.19/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.
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