| 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 in | |
| [include/uapi]<linux/gpio.h> and documented in | |
| Documentation/userspace-api/gpio/chardev.rst. | |
| The following file operations are supported: | |
| open(2) | |
| Currently the only useful flags are O_RDWR. | |
| ioctl(2) | |
| Initiate various actions. | |
| See Documentation/userspace-api/gpio/chardev.rst | |
| for a description of all ioctls. | |
| close(2) | |
| Stops and free up the I/O contexts that was associated | |
| with the file descriptor. | |
| Users: TBD |