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>
This commit is contained in:
William Breathitt Gray 2019-04-02 15:30:41 +09:00 committed by Greg Kroah-Hartman
parent f1d8a071d4
commit 7e798ef90c
2 changed files with 37 additions and 0 deletions

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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.

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@ -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