1*4882a593SmuzhiyunWhat: /dev/gpiochip[0-9]+ 2*4882a593SmuzhiyunDate: November 2015 3*4882a593SmuzhiyunKernelVersion: 4.4 4*4882a593SmuzhiyunContact: linux-gpio@vger.kernel.org 5*4882a593SmuzhiyunDescription: 6*4882a593Smuzhiyun The character device files /dev/gpiochip* are the interface 7*4882a593Smuzhiyun between GPIO chips and userspace. 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun The ioctl(2)-based ABI is defined and documented in 10*4882a593Smuzhiyun [include/uapi]<linux/gpio.h>. 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun The following file operations are supported: 13*4882a593Smuzhiyun 14*4882a593Smuzhiyun open(2) 15*4882a593Smuzhiyun Currently the only useful flags are O_RDWR. 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun ioctl(2) 18*4882a593Smuzhiyun Initiate various actions. 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun See the inline documentation in [include/uapi]<linux/gpio.h> 21*4882a593Smuzhiyun for descriptions of all ioctls. 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun close(2) 24*4882a593Smuzhiyun Stops and free up the I/O contexts that was associated 25*4882a593Smuzhiyun with the file descriptor. 26*4882a593Smuzhiyun 27*4882a593SmuzhiyunUsers: TBD 28