This patch adds standard documentation for the userspace sysfs attributes of the Generic Counter interface.
Signed-off-by: William Breathitt Gray <[email protected]> --- Documentation/ABI/testing/sysfs-bus-counter | 120 ++++++++++++++++++++++++++++ MAINTAINERS | 1 + 2 files changed, 121 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-counter diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter new file mode 100644 index 000000000000..64785aab1763 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -0,0 +1,120 @@ +What: /sys/bus/counter/devices/counterX/countY/count +KernelVersion: 4.17 +Contact: [email protected] +Description: + Count data of Count Y. The following data types are available: + + COUNT_POSITION_UNSIGNED: + Unsigned integer value representing position. + + COUNT_POSITION_SIGNED: + Signed integer value representing position. + +What: /sys/bus/counter/devices/counterX/countY/function +KernelVersion: 4.17 +Contact: [email protected] +Description: + Count function mode of Count Y; count function evaluation is + triggered by conditions specified by the countY_signalZ_action + attributes. The following count functions are available: + + Increase: + Accumulated count is incremented. + + Decrease: + Accumulated count is decremented. + + 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/function_available +KernelVersion: 4.17 +Contact: [email protected] +Description: + Discrete set of available count function modes for the + configuration of the respective Count Y are listed in this file. + +What: /sys/bus/counter/devices/counterX/countY/name +KernelVersion: 4.17 +Contact: [email protected] +Description: + Read-only attribute that indicates the device-specific name of + Count Y. If possible, this should match the name of the + respective channel as it appears in the device datasheet + documentation text. + +What: /sys/bus/counter/devices/counterX/countY/signalZ_action +KernelVersion: 4.17 +Contact: [email protected] +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. The following action modes are + available: + + 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/countY/signalZ_action_available +KernelVersion: 4.17 +Contact: [email protected] +Description: + Discrete set of available action modes are listed in this file + for the configuration of the respective Synapse associating + Signal Z to Count Y. + +What: /sys/bus/counter/devices/counterX/name +KernelVersion: 4.17 +Contact: [email protected] +Description: + Read-only attribute that indicates the device-specific name of + the Counter. This should match the name of the device as it + appears in its respective datasheet documentation text. + +What: /sys/bus/counter/devices/counterX/signalY/signal +KernelVersion: 4.17 +Contact: [email protected] +Description: + Signal data of Signal Y. The following data types are available: + + SIGNAL_LEVEL: + Respective input has two discrete states: Low and High. + +What: /sys/bus/counter/devices/counterX/signalY/name +KernelVersion: 4.17 +Contact: [email protected] +Description: + Read-only attribute that indicates the device-specific name of + Signal Y. If possible, this should match the name of the + respective signal as it appears in the device datasheet + documentation text. diff --git a/MAINTAINERS b/MAINTAINERS index 2be01a95b7a5..2a7bf2f84272 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3672,6 +3672,7 @@ COUNTER SUBSYSTEM M: William Breathitt Gray <[email protected]> L: [email protected] S: Maintained +F: Documentation/ABI/testing/sysfs-bus-counter* F: drivers/counter/ F: include/linux/counter.h -- 2.16.2
