This is the bulk of GPIO changes for the v4.9 series: Subsystem improvements: - Do away with the last users of the obsolete Kconfig options ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB (the latter always sounded like an item on a wishlist to Santa Claus to me). We can now select GPIOLIB and be done with it, for all archs. After some struggle it even work on UM. Not that it has GPIO, but if it wants to, it can select the library. - Continued efforts to make drivers properly either tristate or bool. - Introduce a warning for drivers assigning default triggers to their irqchip lines when probed from device tree, so we find and fix these ambigous drivers. It is agreed that in the OF config path, the device tree defines trigger characteristics. - The same warning, mutatis mutandis, for ACPI-probed GPIO irqchips. - We introduce the ability to mark certain IRQ lines as "unusable" as they can be taken by BIOS/firmware, unrouted in silicon and generally nasty if you use them, and such things. This is put to good use in the STMPE driver and also in the Cherryview pin control driver. - A new "mockup" virtual GPIO device that can be used for testing. The plan is to add unit tests under tools/* for exercising this device and verify that the kernel code paths are working as they should. - Make memory-mapped I/O-drivers depend on HAS_IOMEM. This was implicit all the time, but when people started building UM with allyesconfig or allmodconfig it exploded in their face. - Move some stray bits of device tree and ACPI HW description callbacks down into their respective implementation silo. These were causing issues when compiling on !HAS_IOMEM as well, so now eventually UM compiles the GPIOLIB library if it wants to. New drivers: - New driver for the Aspeed GPIO front-end companion to the pin controller merged through the pin control tree. - New driver for the LP873x PMIC GPIO portions. - New driver for Technologic Systems' I2C FPGA GPIO such as TS4900, TS-7970, TS-7990 and TS-4100. - New driver for the Broadcom BCM63xx series including BCM6338 and BCM6345. - New driver for the Intel WhiskeyCove PMIC GPIO. - New driver for the Allwinner AXP209 PMIC GPIO portions. - New driver for Diamond Systems 48 line GPIO-MM, another of these port-mapped I/O expansion cards. - Support the STMicroelectronics STMPE1600 variant in the STMPE driver. Driver improvements: - The STMPE driver now supports rising/falling edge detection properly for IRQs. - The PCA954x will now fetch and enable its VCC regulator properly. - Major rework of the PCA953x driver with the goal of eventually switching it over to use regmap and thus modernize it even more. - Switch the IOP driver to use the generic MMIO GPIO library. - Move the ages old HTC EGPIO (extended GPIO) GPIO expander driver over to this subsystem from MFD, achieveing some separation of concerns.