| 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 |