From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Breathitt Gray Subject: Re: [PATCH v10 02/18] counter: Documentation: Add Generic Counter sysfs documentation Date: Tue, 9 Apr 2019 14:07:08 +0900 Message-ID: <20190409050708.GB2842@icarus> References: <20190408215531.GB27592@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20190408215531.GB27592@amd> Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: gregkh@linuxfoundation.org, jic23@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, fabrice.gasnier@st.com, benjamin.gaignard@st.com, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, akpm@linux-foundation.org, david@lechnology.com, robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org, leoyang.li@nxp.com, daniel.lezcano@linaro.org, tglx@linutronix.de, thierry.reding@gmail.com, esben@haabendal.dk, linux-pwm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, patrick.havelange@essensium.com, Jonathan Cameron List-Id: devicetree@vger.kernel.org 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 > > Signed-off-by: William Breathitt Gray > > --- > > 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