| 1 | What: /dev/gpiochip[0-9]+ |
| 2 | Date: November 2015 |
| 3 | KernelVersion: 4.4 |
| 4 | Contact: [email protected] |
| 5 | Description: |
| 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 in |
| 10 | [include/uapi]<linux/gpio.h> and documented in |
| 11 | Documentation/userspace-api/gpio/chardev.rst. |
| 12 | |
| 13 | The following file operations are supported: |
| 14 | |
| 15 | open(2) |
| 16 | Currently the only useful flags are O_RDWR. |
| 17 | |
| 18 | ioctl(2) |
| 19 | Initiate various actions. |
| 20 | |
| 21 | See Documentation/userspace-api/gpio/chardev.rst |
| 22 | for a description of all ioctls. |
| 23 | |
| 24 | close(2) |
| 25 | Stops and free up the I/O contexts that was associated |
| 26 | with the file descriptor. |
| 27 | |
| 28 | Users: TBD |