K 10 svn:author V 4 loos K 8 svn:date V 27 2015-01-31T15:50:19.135607Z K 7 svn:log V 439 Implement a new method to retrieve the gpiobus reference from a GPIO controller. The gpiobus is responsible to keep track of the used pins and serialize the access to pins. Some of these features are important to devices that do not descend directly from gpiobus and as such cannot make use of its features (one classic example is gpioc that is attached to the GPIO controller and could not, until now, make use of the gpiobus locking). END