History log of /linux-master/Documentation/ABI/testing/sysfs-class-pwm
Revision Date Author Comments
# 80dd7ae1 13-Jul-2022 Lee Jones <lee@kernel.org>

docs: ABI: sysfs-class-pwm: Update Lee Jones' email address

Going forward, I'll be using my kernel.org for upstream work.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220714112533.539910-5-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 24e83d41 16-Sep-2021 Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

ABI: sysfs-class-pwm: use wildcards on What definitions

An "N" upper letter is not a wildcard, nor can easily be identified
by script, specially since the USB sysfs define things like.
bNumInterfaces. Use, instead, <N>, in order to let script/get_abi.pl
to convert it into a Regex.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/eb3edca0f3cf693d8d28ee7bd00339cac2039014.1631782432.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 1a366fe9 08-Jun-2016 Lee Jones <lee.jones@linaro.org>

pwm: sysfs: Add PWM capture support

Allow a user to read PWM capture results from sysfs. To start a capture
and read the result, simply read the file:

$ cat $PWMCHIP/capture

The output format is "<period> <duty cycle>".

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>


# 76abbdde 11-Jun-2013 H Hartley Sweeten <hartleys@visionengravers.com>

pwm: Add sysfs interface

Add a simple sysfs interface to the generic PWM framework.

/sys/class/pwm/
`-- pwmchipN/ for each PWM chip
|-- export (w/o) ask the kernel to export a PWM channel
|-- npwm (r/o) number of PWM channels in this PWM chip
|-- pwmX/ for each exported PWM channel
| |-- duty_cycle (r/w) duty cycle (in nanoseconds)
| |-- enable (r/w) enable/disable PWM
| |-- period (r/w) period (in nanoseconds)
| `-- polarity (r/w) polarity of PWM (normal/inversed)
`-- unexport (w/o) return a PWM channel to the kernel

Based on work by Lars Poeschel.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>