This is the bulk of GPIO changes for the v4.15 kernel cycle: CORE: - Fix the semantics of raw GPIO to actually be raw. No inversion semantics as before, but also no open draining, and allow the raw operations to affect lines used for interrupts as the caller supposedly knows what they are doing if they are getting the big hammer. - Rewrote the __inner_function() notation calls to names that make more sense. I just find this kind of code disturbing. - Drop the .irq_base() field from the gpiochip since now all IRQs are mapped dynamically. This is nice. - Support for .get_multiple() in the core driver API. This allows us to read several GPIO lines with a single register read. This has high value for some usecases: it can be used to create oscilloscopes and signal analyzers and other things that rely on reading several lines at exactly the same instant. Also a generally nice optimization. This uses the new assign_bit() macro from the bitops lib that was ACKed by Andrew Morton and is implemented for two drivers, one of them being the generic MMIO driver so everyone using that will be able to benefit from this. - Do not allow requests of Open Drain and Open Source setting of a GPIO line simultaneously. If the hardware actually supports enabling both at the same time the electrical result would be disastrous. - A new interrupt chip core helper. This will be helpful to deal with "banked" GPIOs, which means GPIO controllers with several logical blocks of GPIO inside them. This is several gpiochips per device in the device model, in contrast to the case when there is a 1-to-1 relationship between a device and a gpiochip. NEW DRIVERS: - Maxim MAX3191x industrial serializer, a very interesting piece of professional I/O hardware. - Uniphier GPIO driver. This is the GPIO block from the recent Socionext (ex Fujitsu and Panasonic) platform. - Tegra 186 driver. This is based on the new banked GPIO infrastructure. OTHER IMPROVEMENTS: - Some documentation improvements. - Wakeup support for the DesignWare DWAPB GPIO controller. - Reset line support on the DesignWare DWAPB GPIO controller. - Several non-critical bug fixes and improvements for the Broadcom BRCMSTB driver. - Misc non-critical bug fixes like exotic errorpaths, removal of dead code etc. - Explicit comments on fall-through switch() statements.