admin-guide/gpio/gpio-virtuser.rst

3 Virtual GPIO Consumer
6 The virtual GPIO Consumer module allows users to instantiate virtual devices
10 A virtual consumer uses the driver-facing GPIO APIs and allows to cover it with
14 Creating GPIO consumers
35 This is a directory representing a GPIO consumer device.
46 Creating GPIO lookup tables
53 The ``'con_id'`` directory represents a single GPIO lookup and its value maps
57 Users can assign a number of GPIOs to each lookup. Each GPIO is a sub-directory
72 This is a group describing a single GPIO in the ``con_id-gpios`` property.
78 The ``'key'`` attribute represents either the name of the chip this GPIO
79 belongs to or the GPIO line name. This depends on the value of the ``'offset'``
84 The remaining attributes map to the ``'flags'`` field of the GPIO lookup
92 Activating GPIO consumers
104 Virtual GPIO consumers can also be defined in device-tree. The compatible string
106 standardized GPIO pattern.
108 An example device-tree code defining a virtual GPIO consumer:
119 Controlling virtual GPIO consumers
122 Once active, the device will export debugfs attributes for controlling GPIO
123 arrays as well as each requested GPIO line separately. Let's consider the
130 This is the group that will contain the attributes for the entire GPIO array.
136 Both attributes allow to read and set arrays of GPIO values. User must pass
138 containing zeroes and ones representing inactive and active GPIO states
142 will execute the GPIO driver callbacks in interrupt context.
146 This is a group that represents a single GPIO with ``$index`` being its offset
151 Allows to set and read the consumer label of the GPIO line.
155 Allows to set and read the debounce period of the GPIO line.
161 These two attributes allow to set the direction of the GPIO line. They accept
168 make the module listen for edge interrupts on the GPIO. Writing ``0`` disables
176 Both attributes allow to read and set values of individual requested GPIO lines.