diff options
Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/gpio-cdev | 26 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-gpio | 28 |
2 files changed, 26 insertions, 28 deletions
diff --git a/Documentation/ABI/testing/gpio-cdev b/Documentation/ABI/testing/gpio-cdev new file mode 100644 index 000000000000..7b265fbb47e3 --- /dev/null +++ b/Documentation/ABI/testing/gpio-cdev @@ -0,0 +1,26 @@ +What: /dev/gpiochip[0-9]+ +Date: November 2015 +KernelVersion: 4.4 +Contact: linux-gpio@vger.kernel.org +Description: + The character device files /dev/gpiochip* are the interface + between GPIO chips and userspace. + + The ioctl(2)-based ABI is defined and documented in + [include/uapi]<linux/gpio.h>. + + The following file operations are supported: + + open(2) + Currently the only useful flags are O_RDWR. + + ioctl(2) + Initiate various actions. + See the inline documentation in [include/uapi]<linux/gpio.h> + for descriptions of all ioctls. + + close(2) + Stops and free up the I/O contexts that was associated + with the file descriptor. + +Users: TBD diff --git a/Documentation/ABI/testing/sysfs-gpio b/Documentation/ABI/testing/sysfs-gpio deleted file mode 100644 index 55ffa2df1c10..000000000000 --- a/Documentation/ABI/testing/sysfs-gpio +++ /dev/null @@ -1,28 +0,0 @@ -What: /sys/class/gpio/ -Date: July 2008 -KernelVersion: 2.6.27 -Contact: David Brownell <dbrownell@users.sourceforge.net> -Description: - - As a Kconfig option, individual GPIO signals may be accessed from - userspace. GPIOs are only made available to userspace by an explicit - "export" operation. If a given GPIO is not claimed for use by - kernel code, it may be exported by userspace (and unexported later). - Kernel code may export it for complete or partial access. - - GPIOs are identified as they are inside the kernel, using integers in - the range 0..INT_MAX. See Documentation/gpio.txt for more information. - - /sys/class/gpio - /export ... asks the kernel to export a GPIO to userspace - /unexport ... to return a GPIO to the kernel - /gpioN ... for each exported GPIO #N OR - /<LINE-NAME> ... for a properly named GPIO line - /value ... always readable, writes fail for input GPIOs - /direction ... r/w as: in, out (default low); write: high, low - /edge ... r/w as: none, falling, rising, both - /gpiochipN ... for each gpiochip; #N is its first GPIO - /base ... (r/o) same as N - /label ... (r/o) descriptive, not necessarily unique - /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1) - |