xref: /linux/Documentation/ABI/testing/gpio-cdev (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1What:		/dev/gpiochip[0-9]+
2Date:		November 2015
3KernelVersion:	4.4
4Contact:	linux-gpio@vger.kernel.org
5Description:
6		The character device files /dev/gpiochip* are the interface
7		between GPIO chips and userspace.
8
9		The ioctl(2)-based ABI is defined and documented in
10		[include/uapi]<linux/gpio.h>.
11
12		The following file operations are supported:
13
14		open(2)
15		Currently the only useful flags are O_RDWR.
16
17		ioctl(2)
18		Initiate various actions.
19		See the inline documentation in [include/uapi]<linux/gpio.h>
20		for descriptions of all ioctls.
21
22		close(2)
23		Stops and free up the I/O contexts that was associated
24		with the file descriptor.
25
26Users:		TBD
27