device-tree-bindings/gpio/gpio.txt

4 1) gpios property
18 for compatibility reasons (resolving to the "gpios" property), it is not allowed
23 distinct functions, reference each of them under its own property, giving it a
27 The exact purpose of each gpios property must be documented in the device tree
91 a1) (Preferred) Dictated by a binding-specific DT property.
116 property, and a #gpio-cells integer property, which indicates the number of
143 controllers. The gpio-ranges property described below represents this, and
160 <count> set to 0), the property gpio-ranges-group-names contains one string
173 were referenced by any gpio-ranges property to contain a property named
175 However, that property may still exist in older device trees for
223 - gpio-hog:   A property specifying that this child node represents a GPIO hog.
230 - input:      A property specifying to set the GPIO direction as input.
231 - output-low  A property specifying to set the GPIO direction as output with
233 - output-high A property specifying to set the GPIO direction as output with