Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v4.21 kernel series.

  Core changes:

   - Some core changes are already in outside of this pull request as
     they came through the regulator tree, most notably
     devm_gpiod_unhinge() that removes devres refcount management from a
     GPIO descriptor. This is needed in subsystems such as regulators
     where the regulator core need to take over the reference counting
     and lifecycle management for a GPIO descriptor.

   - We dropped devm_gpiochip_remove() and devm_gpio_chip_match() as
     nothing needs it. We can bring it back if need be.

   - Add a global TODO so people see where we are going. This helps
     setting the direction now that we are two GPIO maintainers.

   - Handle the MMC CD/WP properties in the device tree core. (The bulk
     of patches activating this code is already merged through the
     MMC/SD tree.)

   - Augment gpiochip_request_own_desc() to pass a flag so we as
     gpiochips can request lines as active low or open drain etc even
     from ourselves.

  New drivers:

   - New driver for Cadence GPIO blocks.

   - New driver for Atmel SAMA5D2 PIOBU GPIO lines.

  Driver improvements:

   - A major refactoring of the PCA953x driver - this driver has been
     around for ages, and is now modernized to reduce code duplication
     that has stacked up and is using regmap to read write and cache
     registers.

   - Intel drivers are now maintained in a separate tree and start with
     a round of cleanups and unifications"

* tag 'gpio-v4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (99 commits)
  gpio: sama5d2-piobu: Depend on OF_GPIO
  gpio: Add Cadence GPIO driver
  dt-bindings: gpio: Add bindings for Cadence GPIO
  gpiolib-acpi: remove unused variable 'err', cleans up build warning
  gpio: mxs: read pin level directly instead of using .get
  gpio: aspeed: remove duplicated statement
  gpio: add driver for SAMA5D2 PIOBU pins
  dt-bindings: arm: atmel: describe SECUMOD usage as a GPIO controller
  gpio/mmc/of: Respect polarity in the device tree
  dt-bindings: gpio: rcar: Add r8a774c0 (RZ/G2E) support
  memory: omap-gpmc: Get the header of the enum
  ARM: omap1: Fix new user of gpiochip_request_own_desc()
  gpio: pca953x: Add regmap dependency for PCA953x driver
  gpio: raspberrypi-exp: decrease refcount on firmware dt node
  gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIB
  gpio: pca953x: Restore registers after suspend/resume cycle
  gpio: pca953x: Zap single use of pca953x_read_single()
  gpio: pca953x: Zap ad-hoc reg_output cache
  gpio: pca953x: Zap ad-hoc reg_direction cache
  gpio: pca953x: Perform basic regmap conversion
  ...