162306a36Sopenharmony_ciWhat: /dev/gpiochip[0-9]+ 262306a36Sopenharmony_ciDate: November 2015 362306a36Sopenharmony_ciKernelVersion: 4.4 462306a36Sopenharmony_ciContact: linux-gpio@vger.kernel.org 562306a36Sopenharmony_ciDescription: 662306a36Sopenharmony_ci The character device files /dev/gpiochip* are the interface 762306a36Sopenharmony_ci between GPIO chips and userspace. 862306a36Sopenharmony_ci 962306a36Sopenharmony_ci The ioctl(2)-based ABI is defined and documented in 1062306a36Sopenharmony_ci [include/uapi]<linux/gpio.h>. 1162306a36Sopenharmony_ci 1262306a36Sopenharmony_ci The following file operations are supported: 1362306a36Sopenharmony_ci 1462306a36Sopenharmony_ci open(2) 1562306a36Sopenharmony_ci Currently the only useful flags are O_RDWR. 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ci ioctl(2) 1862306a36Sopenharmony_ci Initiate various actions. 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ci See the inline documentation in [include/uapi]<linux/gpio.h> 2162306a36Sopenharmony_ci for descriptions of all ioctls. 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_ci close(2) 2462306a36Sopenharmony_ci Stops and free up the I/O contexts that was associated 2562306a36Sopenharmony_ci with the file descriptor. 2662306a36Sopenharmony_ci 2762306a36Sopenharmony_ciUsers: TBD 28