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Diffstat (limited to 'Documentation/ABI/testing/gpio-cdev')
| -rw-r--r-- | Documentation/ABI/testing/gpio-cdev | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/gpio-cdev b/Documentation/ABI/testing/gpio-cdev new file mode 100644 index 000000000..66bdcd188 --- /dev/null +++ b/Documentation/ABI/testing/gpio-cdev @@ -0,0 +1,27 @@ +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 |