This patch adds standard documentation for the Generic Counter interface userspace sysfs attributes of the 104-QUAD-8 driver.
Signed-off-by: William Breathitt Gray <vilhelm.g...@gmail.com> --- .../ABI/testing/sysfs-bus-counter-104-quad-8 | 115 +++++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 116 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 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 000000000000..4269b438185a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-counter-104-quad-8 @@ -0,0 +1,115 @@ +What: /sys/bus/counter/devices/counterX/countY_count_mode +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Count mode for channel Y. The preset value for channel Y is used + by the count mode where required. The following count modes are + available: + + Normal: + Counting is continuous in either direction. + + Range Limit: + An upper or lower limit is set, mimicking limit switches + in the mechanical counterpart. The upper limit is set to + the preset value, while the lower limit is set to 0. The + counter freezes at count = preset when counting up, and + at count = 0 when counting down. At either of these + limits, the counting is resumed only when the count + direction is reversed. + + Non-recycle: + Counter is disabled whenever a 24-bit count overflow or + underflow takes place. The counter is re-enabled when a + new count value is loaded to the counter via a preset + operation or write to raw. + + Modulo-N: + A count boundary is set between 0 and the preset value. + The counter is reset to 0 at count = preset when + counting up, while the counter is set to the preset + value at count = 0 when counting down; the counter does + not freeze at the bundary points, but counts + continuously throughout. + +What: /sys/bus/counter/devices/counterX/countY_count_mode_available +What: /sys/bus/counter/devices/counterX/countY_noise_error_available +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Discrete set of available values for the respective Count Y + configuration are listed in this file. + +What: /sys/bus/counter/devices/counterX/countY_direction +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Read-only attribute that indicates the count direction of + Count Y. Two count directions are available: Forward and + Backward. + +What: /sys/bus/counter/devices/counterX/countY_enable +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Whether channel Y inputs A and B are enabled. Valid attribute + values are boolean. + +What: /sys/bus/counter/devices/counterX/countY_noise_error +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Read-only attribute that indicates whether excessive noise is + present at the channel Y count inputs in quadrature clock mode; + irrelevant in non-quadrature (Pulse-Direction) clock mode. + +What: /sys/bus/counter/devices/counterX/countY_preset +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + If the counter device supports preset registers, the preset + count for channel Y is provided by this attribute. + +What: /sys/bus/counter/devices/counterX/countY_preset_enable +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Whether to set channel Y counter with channel Y preset value + when channel Y index input is active, or continuously count. + Valid attribute values are boolean. + +What: /sys/bus/counter/devices/counterX/signalY_index_polarity +KernelVersion: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Active level of channel Y-16 index input; 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: 4.17 +Contact: linux-...@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: 4.17 +Contact: linux-...@vger.kernel.org +Description: + Configure channel Y-16 counter 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 febe27a9962e..8134050d175a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -270,6 +270,7 @@ ACCES 104-QUAD-8 DRIVER M: William Breathitt Gray <vilhelm.g...@gmail.com> L: linux-...@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 -- 2.16.2
