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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8')
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1 files changed, 125 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8 b/Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8 new file mode 100644 index 000000000000..ba676520b953 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8 @@ -0,0 +1,125 @@ +What: /sys/bus/iio/devices/iio:deviceX/in_count_count_direction_available +What: /sys/bus/iio/devices/iio:deviceX/in_count_count_mode_available +What: /sys/bus/iio/devices/iio:deviceX/in_count_noise_error_available +What: /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available +What: /sys/bus/iio/devices/iio:deviceX/in_index_index_polarity_available +What: /sys/bus/iio/devices/iio:deviceX/in_index_synchronous_mode_available +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Discrete set of available values for the respective counter + configuration are listed in this file. + +What: /sys/bus/iio/devices/iio:deviceX/in_countY_count_direction +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates whether the counter for + channel Y is counting up or down. + +What: /sys/bus/iio/devices/iio:deviceX/in_countY_count_mode +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Count mode for channel Y. Four count modes are available: + normal, range limit, non-recycle, and modulo-n. The preset value + for channel Y is used by the count mode where required. + + 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/iio/devices/iio:deviceX/in_countY_noise_error +KernelVersion: 4.9 +Contact: linux-iio@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 clock mode. + +What: /sys/bus/iio/devices/iio:deviceX/in_countY_preset +KernelVersion: 4.9 +Contact: linux-iio@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/iio/devices/iio:deviceX/in_countY_quadrature_mode +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Configure channel Y counter for non-quadrature or quadrature + clock mode. Selecting non-quadrature clock mode will disable + synchronous load mode. In quadrature clock mode, the channel Y + scale attribute selects the encoder phase division (scale of 1 + selects full-cycle, scale of 0.5 selects half-cycle, scale of + 0.25 selects quarter-cycle) processed by the channel Y counter. + + Non-quadrature: + The filter and decoder circuit are bypassed. Encoder A + input serves as the count input and B as the UP/DOWN + direction control input, with B = 1 selecting UP Count + mode and B = 0 selecting Down Count mode. + + Quadrature: + Encoder A and B inputs are digitally filtered and + decoded for UP/DN clock. + +What: /sys/bus/iio/devices/iio:deviceX/in_countY_set_to_preset_on_index +KernelVersion: 4.9 +Contact: linux-iio@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/iio/devices/iio:deviceX/in_indexY_index_polarity +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Active level of channel Y index input; irrelevant in + non-synchronous load mode. + +What: /sys/bus/iio/devices/iio:deviceX/in_indexY_synchronous_mode +KernelVersion: 4.9 +Contact: linux-iio@vger.kernel.org +Description: + Configure channel Y counter for non-synchronous or synchronous + load mode. Synchronous load mode cannot be selected in + non-quadrature clock mode. + + Non-synchronous: + A logic low level is the active level at this index + input. The index function (as enabled via + set_to_preset_on_index) 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 + set_to_preset_on_index) is performed synchronously with + the quadrature clock on the active level of the index + input. |