admin-guide/gpio/gpio-aggregator.rst

3 GPIO Aggregator
6 The GPIO Aggregator provides a mechanism to aggregate GPIOs, and expose them as
13 GPIO controllers are exported to userspace using /dev/gpiochip* character
15 system permissions, on an all-or-nothing basis: either a GPIO controller is
18 The GPIO Aggregator provides access control for a set of one or more GPIOs, by
22 grab the full GPIO controller, and no longer needs to care about which GPIOs to
25 Aggregated GPIO controllers are instantiated and destroyed by writing to
31 		Userspace may ask the kernel to instantiate an aggregated GPIO
42 			    is a GPIO line name,
45 			    is a GPIO chip label, and
48 			    is a comma-separated list of GPIO offsets and/or
49 			    GPIO offset ranges denoted by dashes.
51 		Example: Instantiate a new GPIO aggregator by aggregating GPIO
52 		line 19 of "e6052000.gpio" and GPIO lines 20-21 of
60 		Userspace may ask the kernel to destroy an aggregated GPIO
64 		Example: Destroy the previously-created aggregated GPIO
72 Generic GPIO Driver
75 The GPIO Aggregator can also be used as a generic driver for a simple
76 GPIO-operated device described in DT, without a dedicated in-kernel driver.
80 Binding a device to the GPIO Aggregator is performed either by modifying the
83 Example: If "door" is a GPIO-operated device described in DT, using its own
94 it can be bound to the GPIO Aggregator by either: