140c159b7SLinus WalleijWhat:		/dev/gpiochip[0-9]+
240c159b7SLinus WalleijDate:		November 2015
340c159b7SLinus WalleijKernelVersion:	4.4
440c159b7SLinus WalleijContact:	linux-gpio@vger.kernel.org
540c159b7SLinus WalleijDescription:
640c159b7SLinus Walleij		The character device files /dev/gpiochip* are the interface
740c159b7SLinus Walleij		between GPIO chips and userspace.
840c159b7SLinus Walleij
940c159b7SLinus Walleij		The ioctl(2)-based ABI is defined and documented in
1040c159b7SLinus Walleij		[include/uapi]<linux/gpio.h>.
1140c159b7SLinus Walleij
1240c159b7SLinus Walleij		The following file operations are supported:
1340c159b7SLinus Walleij
1440c159b7SLinus Walleij		open(2)
1540c159b7SLinus Walleij		  Currently the only useful flags are O_RDWR.
1640c159b7SLinus Walleij
1740c159b7SLinus Walleij		ioctl(2)
1840c159b7SLinus Walleij		  Initiate various actions.
1954a19b4dSMauro Carvalho Chehab
2040c159b7SLinus Walleij		  See the inline documentation in [include/uapi]<linux/gpio.h>
2140c159b7SLinus Walleij		  for descriptions of all ioctls.
2240c159b7SLinus Walleij
2340c159b7SLinus Walleij		close(2)
2440c159b7SLinus Walleij		  Stops and free up the I/O contexts that was associated
2540c159b7SLinus Walleij		  with the file descriptor.
2640c159b7SLinus Walleij
2740c159b7SLinus WalleijUsers:		TBD
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