Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8
new file mode 100644
index 0000000..46b1f33
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8
@@ -0,0 +1,36 @@
+What:		/sys/bus/counter/devices/counterX/signalY/index_polarity
+KernelVersion:	5.2
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Active level of index input Signal Y; irrelevant in
+		non-synchronous load mode.
+
+What:		/sys/bus/counter/devices/counterX/signalY/index_polarity_available
+What:		/sys/bus/counter/devices/counterX/signalY/synchronous_mode_available
+KernelVersion:	5.2
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Discrete set of available values for the respective Signal Y
+		configuration are listed in this file.
+
+What:		/sys/bus/counter/devices/counterX/signalY/synchronous_mode
+KernelVersion:	5.2
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Configure the counter associated with Signal Y for
+		non-synchronous or synchronous load mode. Synchronous load mode
+		cannot be selected in non-quadrature (Pulse-Direction) clock
+		mode.
+
+		non-synchronous:
+			A logic low level is the active level at this index
+			input. The index function (as enabled via preset_enable)
+			is performed directly on the active level of the index
+			input.
+
+		synchronous:
+			Intended for interfacing with encoder Index output in
+			quadrature clock mode. The active level is configured
+			via index_polarity. The index function (as enabled via
+			preset_enable) is performed synchronously with the
+			quadrature clock on the active level of the index input.