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+What: /sys/bus/counter/devices/counterX/countY
+KernelVersion: 4.16
+Contact: linux-iio@vger.kernel.org
+Description:
+ Count data of Count Y. This is a signed integer value that
+ represents the position. Typically, this is determined by
+ hardware evaluation of the quadrature encoding input signals.
+
+What: /sys/bus/counter/devices/counterX/countY_direction
+KernelVersion: 4.16
+Contact: linux-iio@vger.kernel.org
+Description:
+ Count direction of Count Y. Typically, this is determined by
+ hardware evaluation of the quadrature encoding input signals.
+ Two count directions are available: forward and backward.
+
+What: /sys/bus/counter/devices/counterX/countY_function
+KernelVersion: 4.16
+Contact: linux-iio@vger.kernel.org
+Description:
+ Count function mode of Count Y. Count function evaluation is
+ triggered by conditions specified by the countY_signalZ_action
+ attributes. Four count function modes are available:
+ pulse-direction, quadrature x1, quadrature x2, quadrature x4.
+
+ Pulse-Direction:
+ Rising edges on quadrature pair signal A updates the
+ respective count. The input level of quadrature pair
+ signal B determines direction.
+
+ Quadrature x1:
+ If direction is forward, rising edges on quadrature pair
+ signal A updates the respective count; if the direction
+ is backward, falling edges on quadrature pair signal A
+ updates the respective count. Quadrature encoding
+ determines the direction.
+
+ Quadrature x2:
+ Any state transition on quadrature pair signal A updates
+ the respective count. Quadrature encoding determines the
+ direction.
+
+ Quadrature x4:
+ Any state transition on either quadrature pair signals
+ updates the respective count. Quadrature encoding
+ determines the direction.
+
+What: /sys/bus/counter/devices/counterX/countY_signalZ_action
+KernelVersion: 4.16
+Contact: linux-iio@vger.kernel.org
+Description:
+ Action mode of Count Y for Signal Z. This attribute indicates
+ the condition of Signal Z that triggers the count function
+ evaluation for Count Y. Four action modes are available: none,
+ rising edge, falling edge, and both edges.
+
+ None:
+ Signal does not trigger the count function. In
+ Pulse-Direction count function mode, this Signal is
+ evaluated as Direction.
+
+ Rising Edge:
+ Low state transitions to High state.
+
+ Falling Edge:
+ High state transitions to Low state.
+
+ Both Edges:
+ Any state transition.
+
+What: /sys/bus/counter/devices/counterX/signalY
+KernelVersion: 4.16
+Contact: linux-iio@vger.kernel.org
+Description:
+ Signal data of Signal Y. This is the respective input level
+ represented by two available states: low and high.
This patch adds standard documentation for the userspace sysfs attributes of the Quadrature Counter interface. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> --- .../ABI/testing/sysfs-bus-counter-quadrature-sysfs | 76 ++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-counter-quadrature-sysfs