This is the bulk of GPIO changes for the v4.8 kernel cycle. Core changes: - The big item is of course the completion of the character device ABI. It has now replaced and surpassed the former unmaintainable sysfs ABI: we can now hammer (bitbang) individual lines or sets of lines and read individual lines or sets of lines from userspace, and we can also register to listen to GPIO events from userspace. As a tie-in we have two new tools in tools/gpio: gpio-hammer and gpio-event-mon that illustrate the proper use of the new ABI. As someone said: the wild west days of GPIO are now over. - Continued to remove the pointless ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB Kconfig symbols. I'm patching hexagon, openrisc, powerpc, sh, unicore, ia64 and microblaze. These are either ACKed by their maintainers or patched anyways after a grace period and no response from maintainers. Some archs (ARM) come in from their trees, and others (x86) are still not fixed, so I might send a second pull request to root it out later in this merge window, or just defer to v4.9. - The GPIO tools are moved to the tools build system. New drivers: - New driver for the MAX77620/MAX20024. - New driver for the Intel Merrifield. - Enabled PCA953x for the TI PCA9536. - Enabled PCA953x for the Intel Edison. - Enabled R8A7792 in the RCAR driver. Driver improvements: - The STMPE and F7188x now supports the .get_direction() callback. - The Xilinx driver supports setting multiple lines at once. - ACPI support for the Vulcan GPIO controller. - The MMIO GPIO driver supports device tree probing. - The Acer One 10 is supported through the _DEP ACPI attribute. Cleanups: - A major cleanup of the OF/DT support code. It is way easier to read and understand now, probably this improves performance too. - Drop a few redundant .owner assignments. - Remove CLPS711x boardfile support: we are 100% DT.