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