| Message ID | bd8362f23b99af938c7bced2104eca29888253b3.1554184734.git.vilhelm.gray@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce the Counter subsystem | expand |
On Tue 2019-04-02 15:30:37, William Breathitt Gray wrote: > This patch adds standard documentation for the userspace sysfs > attributes of the Generic Counter interface. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> > --- > Documentation/ABI/testing/sysfs-bus-counter | 230 ++++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 231 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..566bd99fe0a5 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-counter > @@ -0,0 +1,230 @@ > +What: /sys/bus/counter/devices/counterX/countY/count > +KernelVersion: 5.2 > +Contact: linux-iio@vger.kernel.org > +Description: > + Count data of Count Y represented as a string. > + > +What: /sys/bus/counter/devices/counterX/countY/ceiling > +KernelVersion: 5.2 > +Contact: linux-iio@vger.kernel.org > +Description: > + Count value ceiling for Count Y. This is the upper limit for the > + respective counter. > + > +What: /sys/bus/counter/devices/counterX/countY/floor > +KernelVersion: 5.2 > +Contact: linux-iio@vger.kernel.org > +Description: > + Count value floor for Count Y. This is the lower limit for the > + respective counter. > + > +What: /sys/bus/counter/devices/counterX/countY/count_mode > +KernelVersion: 5.2 > +Contact: linux-iio@vger.kernel.org > +Description: > + Count mode for channel Y. The ceiling and floor values for > + Count Y are 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 Count Y ceiling value, while the lower limit is set > + to the Count Y floor value. The counter freezes at > + count = ceiling when counting up, and at count = floor > + when counting down. At either of these limits, the > + counting is resumed only when the count direction is > + reversed. > + > + non-recycle: > + The counter is disabled whenever a counter 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 direct write. > + > + modulo-n: > + A count value boundary is set between the Count Y floor > + value and the Count Y ceiling value. The counter is > + reset to the Count Y floor value at count = ceiling when > + counting up, while the counter is set to the Count Y > + ceiling value at count = floor when counting down; the > + counter does not freeze at the boundary points, but > + counts continuously throughout. > + > +What: /sys/bus/counter/devices/counterX/countY/count_mode_available > +What: /sys/bus/counter/devices/counterX/countY/error_noise_available > +What: /sys/bus/counter/devices/counterX/countY/function_available > +What: /sys/bus/counter/devices/counterX/countY/signalZ_action_available > +KernelVersion: 5.2 > +Contact: linux-iio@vger.kernel.org > +Description: > + Discrete set of available values for the respective Count Y > + configuration are listed in this file. Values are delimited by > + newline characters. Elsewhere in sysfs we do space-separated: pavel@amd:~$ cat /sys/power/state freeze mem disk And we use [] to mark current selection: pavel@amd:~$ cat /sys/class/leds/tpacpi\:\:thinkvantage/trigger [none] bluetooth-power rfkill-any rfkill-none kbd-scrolllock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock AC-online BAT0-charging-or-full BAT0-charging BAT0-full BAT0-charging-blink-full-solid rfkill0 phy0rx phy0tx phy0assoc phy0radio phy0tpt mmc0 timer heartbeat audio-mute audio-micmute rfkill1 Note this only works if you have less than PAGE_SIZE of entries... and will never have more. Pavel
On Mon, Apr 08, 2019 at 11:55:31PM +0200, Pavel Machek wrote: > On Tue 2019-04-02 15:30:37, William Breathitt Gray wrote: > > This patch adds standard documentation for the userspace sysfs > > attributes of the Generic Counter interface. > > > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> > > --- > > Documentation/ABI/testing/sysfs-bus-counter | 230 ++++++++++++++++++++ > > MAINTAINERS | 1 + > > 2 files changed, 231 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..566bd99fe0a5 > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-bus-counter > > @@ -0,0 +1,230 @@ > > +What: /sys/bus/counter/devices/counterX/countY/count > > +KernelVersion: 5.2 > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Count data of Count Y represented as a string. > > + > > +What: /sys/bus/counter/devices/counterX/countY/ceiling > > +KernelVersion: 5.2 > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Count value ceiling for Count Y. This is the upper limit for the > > + respective counter. > > + > > +What: /sys/bus/counter/devices/counterX/countY/floor > > +KernelVersion: 5.2 > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Count value floor for Count Y. This is the lower limit for the > > + respective counter. > > + > > +What: /sys/bus/counter/devices/counterX/countY/count_mode > > +KernelVersion: 5.2 > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Count mode for channel Y. The ceiling and floor values for > > + Count Y are 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 Count Y ceiling value, while the lower limit is set > > + to the Count Y floor value. The counter freezes at > > + count = ceiling when counting up, and at count = floor > > + when counting down. At either of these limits, the > > + counting is resumed only when the count direction is > > + reversed. > > + > > + non-recycle: > > + The counter is disabled whenever a counter 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 direct write. > > + > > + modulo-n: > > + A count value boundary is set between the Count Y floor > > + value and the Count Y ceiling value. The counter is > > + reset to the Count Y floor value at count = ceiling when > > + counting up, while the counter is set to the Count Y > > + ceiling value at count = floor when counting down; the > > + counter does not freeze at the boundary points, but > > + counts continuously throughout. > > + > > +What: /sys/bus/counter/devices/counterX/countY/count_mode_available > > +What: /sys/bus/counter/devices/counterX/countY/error_noise_available > > +What: /sys/bus/counter/devices/counterX/countY/function_available > > +What: /sys/bus/counter/devices/counterX/countY/signalZ_action_available > > +KernelVersion: 5.2 > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Discrete set of available values for the respective Count Y > > + configuration are listed in this file. Values are delimited by > > + newline characters. > > Elsewhere in sysfs we do space-separated: > > pavel@amd:~$ cat /sys/power/state > freeze mem disk > > And we use [] to mark current selection: > > pavel@amd:~$ cat /sys/class/leds/tpacpi\:\:thinkvantage/trigger > [none] bluetooth-power rfkill-any rfkill-none kbd-scrolllock > kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock > kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock > kbd-ctrlrlock AC-online BAT0-charging-or-full BAT0-charging BAT0-full > BAT0-charging-blink-full-solid rfkill0 phy0rx phy0tx phy0assoc > phy0radio phy0tpt mmc0 timer heartbeat audio-mute audio-micmute > rfkill1 > > Note this only works if you have less than PAGE_SIZE of entries... and > will never have more. > > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html Marking the current selection with [] or similar does seem useful. But delimiting by space does seem to cause confusion in cases where the values also include spaces (e.g. "quadrature x1 a"). I see that in these cases a "-" is used in place of a space, but that wouldn't work very well when values can also contain hyphens (e.g. "pulse-direction"). William Breathitt Gray
On 4/8/19 4:55 PM, Pavel Machek wrote: > > pavel@amd:~$ cat /sys/power/state > freeze mem disk > > And we use [] to mark current selection: I know this is used elsewhere, but I don't think it is a good pattern to copy. Parsing it from user-space is annoying. Also it breaks the sysfs rule of "one item per file" since it tells us two things - the list of possible values _and_ the current active value. > > pavel@amd:~$ cat /sys/class/leds/tpacpi\:\:thinkvantage/trigger > [none] bluetooth-power rfkill-any rfkill-none kbd-scrolllock > kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock > kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock > kbd-ctrlrlock AC-online BAT0-charging-or-full BAT0-charging BAT0-full > BAT0-charging-blink-full-solid rfkill0 phy0rx phy0tx phy0assoc > phy0radio phy0tpt mmc0 timer heartbeat audio-mute audio-micmute > rfkill1 > > Note this only works if you have less than PAGE_SIZE of entries... and > will never have more. > > Pavel >
diff --git a/Documentation/ABI/testing/sysfs-bus-counter b/Documentation/ABI/testing/sysfs-bus-counter new file mode 100644 index 000000000000..566bd99fe0a5 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-counter @@ -0,0 +1,230 @@ +What: /sys/bus/counter/devices/counterX/countY/count +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Count data of Count Y represented as a string. + +What: /sys/bus/counter/devices/counterX/countY/ceiling +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Count value ceiling for Count Y. This is the upper limit for the + respective counter. + +What: /sys/bus/counter/devices/counterX/countY/floor +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Count value floor for Count Y. This is the lower limit for the + respective counter. + +What: /sys/bus/counter/devices/counterX/countY/count_mode +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Count mode for channel Y. The ceiling and floor values for + Count Y are 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 Count Y ceiling value, while the lower limit is set + to the Count Y floor value. The counter freezes at + count = ceiling when counting up, and at count = floor + when counting down. At either of these limits, the + counting is resumed only when the count direction is + reversed. + + non-recycle: + The counter is disabled whenever a counter 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 direct write. + + modulo-n: + A count value boundary is set between the Count Y floor + value and the Count Y ceiling value. The counter is + reset to the Count Y floor value at count = ceiling when + counting up, while the counter is set to the Count Y + ceiling value at count = floor when counting down; the + counter does not freeze at the boundary points, but + counts continuously throughout. + +What: /sys/bus/counter/devices/counterX/countY/count_mode_available +What: /sys/bus/counter/devices/counterX/countY/error_noise_available +What: /sys/bus/counter/devices/counterX/countY/function_available +What: /sys/bus/counter/devices/counterX/countY/signalZ_action_available +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Discrete set of available values for the respective Count Y + configuration are listed in this file. Values are delimited by + newline characters. + +What: /sys/bus/counter/devices/counterX/countY/direction +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates the count direction of Count + Y. Two count directions are available: forward and backward. + + Some counter devices are able to determine the direction of + their counting. For example, quadrature encoding counters can + determine the direction of movement by evaluating the leading + phase of the respective A and B quadrature encoding signals. + This attribute exposes such count directions. + +What: /sys/bus/counter/devices/counterX/countY/enable +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Whether channel Y counter is enabled. Valid attribute values are + boolean. + + This attribute is intended to serve as a pause/unpause mechanism + for Count Y. Suppose a counter device is used to count the total + movement of a conveyor belt: this attribute allows an operator + to temporarily pause the counter, service the conveyor belt, + and then finally unpause the counter to continue where it had + left off. + +What: /sys/bus/counter/devices/counterX/countY/error_noise +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates whether excessive noise is + present at the channel Y counter inputs. + +What: /sys/bus/counter/devices/counterX/countY/function +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Count function mode of Count Y; count function evaluation is + triggered by conditions specified by the Count Y signalZ_action + attributes. The following count functions are available: + + increase: + Accumulated count is incremented. + + decrease: + Accumulated count is decremented. + + pulse-direction: + Rising edges on signal A updates the respective count. + The input level of signal B determines direction. + + quadrature x1 a: + 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 x1 b: + If direction is forward, rising edges on quadrature pair + signal B updates the respective count; if the direction + is backward, falling edges on quadrature pair signal B + updates the respective count. Quadrature encoding + determines the direction. + + quadrature x2 a: + Any state transition on quadrature pair signal A updates + the respective count. Quadrature encoding determines the + direction. + + quadrature x2 b: + Any state transition on quadrature pair signal B 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/name +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +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. + +What: /sys/bus/counter/devices/counterX/countY/preset +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + If the counter device supports preset registers -- registers + used to load counter channels to a set count upon device-defined + preset operation trigger events -- the preset count for channel + Y is provided by this attribute. + +What: /sys/bus/counter/devices/counterX/countY/preset_enable +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Whether channel Y counter preset operation is enabled. Valid + attribute values are boolean. + +What: /sys/bus/counter/devices/counterX/countY/signalZ_action +KernelVersion: 5.2 +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. 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/name +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +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. + +What: /sys/bus/counter/devices/counterX/num_counts +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates the total number of Counts + belonging to the Counter. + +What: /sys/bus/counter/devices/counterX/num_signals +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Read-only attribute that indicates the total number of Signals + belonging to the Counter. + +What: /sys/bus/counter/devices/counterX/signalY/signal +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +Description: + Signal data of Signal Y represented as a string. + +What: /sys/bus/counter/devices/counterX/signalY/name +KernelVersion: 5.2 +Contact: linux-iio@vger.kernel.org +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. diff --git a/MAINTAINERS b/MAINTAINERS index ef497d470501..af701863a249 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3970,6 +3970,7 @@ COUNTER SUBSYSTEM M: William Breathitt Gray <vilhelm.gray@gmail.com> L: linux-iio@vger.kernel.org S: Maintained +F: Documentation/ABI/testing/sysfs-bus-counter* F: drivers/counter/ F: include/linux/counter.h F: include/linux/counter_enum.h