1*40c159b7SLinus WalleijWhat: /dev/gpiochip[0-9]+ 2*40c159b7SLinus WalleijDate: November 2015 3*40c159b7SLinus WalleijKernelVersion: 4.4 4*40c159b7SLinus WalleijContact: linux-gpio@vger.kernel.org 5*40c159b7SLinus WalleijDescription: 6*40c159b7SLinus Walleij The character device files /dev/gpiochip* are the interface 7*40c159b7SLinus Walleij between GPIO chips and userspace. 8*40c159b7SLinus Walleij 9*40c159b7SLinus Walleij The ioctl(2)-based ABI is defined and documented in 10*40c159b7SLinus Walleij [include/uapi]<linux/gpio.h>. 11*40c159b7SLinus Walleij 12*40c159b7SLinus Walleij The following file operations are supported: 13*40c159b7SLinus Walleij 14*40c159b7SLinus Walleij open(2) 15*40c159b7SLinus Walleij Currently the only useful flags are O_RDWR. 16*40c159b7SLinus Walleij 17*40c159b7SLinus Walleij ioctl(2) 18*40c159b7SLinus Walleij Initiate various actions. 19*40c159b7SLinus Walleij See the inline documentation in [include/uapi]<linux/gpio.h> 20*40c159b7SLinus Walleij for descriptions of all ioctls. 21*40c159b7SLinus Walleij 22*40c159b7SLinus Walleij close(2) 23*40c159b7SLinus Walleij Stops and free up the I/O contexts that was associated 24*40c159b7SLinus Walleij with the file descriptor. 25*40c159b7SLinus Walleij 26*40c159b7SLinus WalleijUsers: TBD 27