Commit e10b6417 authored by Kent Gibson's avatar Kent Gibson Committed by Bartosz Golaszewski
Browse files

Documentation: gpio: update sysfs documentation to reference new chardev doc 



Update GPIO sysfs interface documentation to reference the new
chardev document rather than gpio.h.

Signed-off-by: default avatarKent Gibson <warthog618@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 5054626a

Documentation/userspace-api/gpio/sysfs.rst

+15 −12
Original line number Diff line number Diff line
@@ -2,18 +2,18 @@ GPIO Sysfs Interface for Userspace 
==================================



.. warning::

   This API is obsoleted by the chardev.rst and the ABI documentation has

   been moved to Documentation/ABI/obsolete/sysfs-gpio.



  THIS ABI IS DEPRECATED, THE ABI DOCUMENTATION HAS BEEN MOVED TO

  Documentation/ABI/obsolete/sysfs-gpio AND NEW USERSPACE CONSUMERS

  ARE SUPPOSED TO USE THE CHARACTER DEVICE ABI. THIS OLD SYSFS ABI WILL

  NOT BE DEVELOPED (NO NEW FEATURES), IT WILL JUST BE MAINTAINED.

   New developments should use the chardev.rst, and existing developments are

   encouraged to migrate as soon as possible, as this API will be removed

   in the future.



Refer to the examples in tools/gpio/* for an introduction to the new

character device ABI. Also see the userspace header in

include/uapi/linux/gpio.h

   This interface will continue to be maintained for the migration period,

   but new features will only be added to the new API.



The deprecated sysfs ABI

------------------------

The obsolete sysfs ABI

----------------------

Platforms which use the "gpiolib" implementors framework may choose to

configure a sysfs user interface to GPIOs. This is different from the

debugfs interface, since it provides control over GPIO direction and
@@ -33,9 +33,12 @@ userspace GPIO can be used to determine system configuration data that 
standard kernels won't know about. And for some tasks, simple userspace

GPIO drivers could be all that the system really needs.



DO NOT ABUSE SYSFS TO CONTROL HARDWARE THAT HAS PROPER KERNEL DRIVERS.

PLEASE READ THE DOCUMENT AT Documentation/driver-api/gpio/drivers-on-gpio.rst

TO AVOID REINVENTING KERNEL WHEELS IN USERSPACE. I MEAN IT. REALLY.

.. note::

   Do NOT abuse sysfs to control hardware that has proper kernel drivers.

   Please read Documentation/driver-api/gpio/drivers-on-gpio.rst

   to avoid reinventing kernel wheels in userspace.



   I MEAN IT. REALLY.



Paths in Sysfs

--------------