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 in
10 [include/uapi]<linux/gpio.h> a 10 [include/uapi]<linux/gpio.h> and documented in
11 Documentation/userspace-api/gp 11 Documentation/userspace-api/gpio/chardev.rst.
12 12
13 The following file operations 13 The following file operations are supported:
14 14
15 open(2) 15 open(2)
16 Currently the only useful fl 16 Currently the only useful flags are O_RDWR.
17 17
18 ioctl(2) 18 ioctl(2)
19 Initiate various actions. 19 Initiate various actions.
20 20
21 See Documentation/userspace- 21 See Documentation/userspace-api/gpio/chardev.rst
22 for a description of all ioc 22 for a description of all ioctls.
23 23
24 close(2) 24 close(2)
25 Stops and free up the I/O co 25 Stops and free up the I/O contexts that was associated
26 with the file descriptor. 26 with the file descriptor.
27 27
28 Users: TBD 28 Users: TBD
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