Merge tag 'gpio-v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v5.8 kernel cycle.

  Core changes:

   - A new GPIO aggregator driver has been merged: this can join a few
     select GPIO lines into a new aggregated GPIO chip. This can be used
     for security: a process can be granted access to only these lines,
     for example for industrial control. Another way to use this is to
     reexpose certain select lines to a virtual machine or container.

   - Warn if the gpio-line-names is too long in he DT parser core.

   - GPIO lines can now be looked up by line name in addition to being
     looked up by offset.

  New drivers:

   - A new generic regmap GPIO driver has been merged. Too many regmap
     drivers are starting to look like each other so we need to create
     some common ground and try to move drivers over to using that.

   - The F7188X driver now supports F81865.

  Driver improvements:

   - Large improvements to the PCA953x expander, get multiple lines and
     several cleanups.

   - Large improvements to the DesignWare DWAPB driver, and Sergey Semin
     has volunteered to maintain it.

   - PL061 can now be built as a module, this is part of a bigger effort
     to make the ARM platforms more modular"

* tag 'gpio-v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (77 commits)
  gpio: pca953x: Drop unneeded ACPI_PTR()
  MAINTAINERS: Add gpio regmap section
  gpio: add a reusable generic gpio_chip using regmap
  gpiolib: Introduce gpiochip_irqchip_add_domain()
  gpio: gpiolib: Allow GPIO IRQs to lazy disable
  gpiolib: Separate GPIO_GET_LINEINFO_WATCH_IOCTL conditional
  gpio: rcar: Fix runtime PM imbalance on error
  gpio: pca935x: Allow IRQ support for driver built as a module
  gpio: pxa: Add COMPILE_TEST support
  dt-bindings: gpio: Add renesas,em-gio bindings
  MAINTAINERS: Fix file name for DesignWare GPIO DT schema
  gpio: dwapb: Remove unneeded has_irq member in struct dwapb_port_property
  gpio: dwapb: Don't use IRQ 0 as valid Linux interrupt
  gpio: dwapb: avoid error message for optional IRQ
  gpio: dwapb: Call acpi_gpiochip_free_interrupts() on GPIO chip de-registration
  gpio: max730x: bring gpiochip_add_data after port config
  MAINTAINERS: Add GPIO Aggregator section
  docs: gpio: Add GPIO Aggregator documentation
  gpio: Add GPIO Aggregator
  gpiolib: Add support for GPIO lookup by line name
  ...

1 files changed, 10 insertions, 5 deletions

diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst
index ce91518bf9f4..191fa867826a 100644
--- a/Documentation/driver-api/gpio/board.rst
+++ b/Documentation/driver-api/gpio/board.rst
@@ -113,13 +113,15 @@ files that desire to do so need to include the following header::
 GPIOs are mapped by the means of tables of lookups, containing instances of the
 gpiod_lookup structure. Two macros are defined to help declaring such mappings::
 
-	GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags)
-	GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags)
+	GPIO_LOOKUP(key, chip_hwnum, con_id, flags)
+	GPIO_LOOKUP_IDX(key, chip_hwnum, con_id, idx, flags)
 
 where
 
-  - chip_label is the label of the gpiod_chip instance providing the GPIO
-  - chip_hwnum is the hardware number of the GPIO within the chip
+  - key is either the label of the gpiod_chip instance providing the GPIO, or
+    the GPIO line name
+  - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX
+    to indicate that key is a GPIO line name
   - con_id is the name of the GPIO function from the device point of view. It
 	can be NULL, in which case it will match any function.
   - idx is the index of the GPIO within the function.
@@ -135,7 +137,10 @@ where
 
 In the future, these flags might be extended to support more properties.
 
-Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
+Note that:
+  1. GPIO line names are not guaranteed to be globally unique, so the first
+     match found will be used.
+  2. GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
 
 A lookup table can then be defined as follows, with an empty entry defining its
 end. The 'dev_id' field of the table is the identifier of the device that will