counter: 104-quad-8: Documentation: Add Generic Counter sysfs documentation

This patch adds standard documentation for the Generic Counter interface
userspace sysfs attributes of the 104-QUAD-8 driver.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 (file)
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.

diff --git a/MAINTAINERS b/MAINTAINERS
index 5b01a0c..43a9ceb 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -272,6 +272,7 @@ ACCES 104-QUAD-8 DRIVER
 M:     William Breathitt Gray <vilhelm.gray@gmail.com>
 L:     linux-iio@vger.kernel.org
 S:     Maintained
+F:     Documentation/ABI/testing/sysfs-bus-counter-104-quad-8
 F:     Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8
 F:     drivers/counter/104-quad-8.c