gpiod_set_value() is preffered interface these days, so add a
pointer. Also fix a missing ).

Signed-off-by: Pavel Machek <pavel@ucw.cz>
[Fixed some grammar and reworded]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

When using GPIO irqchip helpers to setup irqchip for a gpiolib based
driver, it is not possible to select which GPIOs to add to the IRQ domain.
Instead it just adds all GPIOs which is not always desired. For example
there might be GPIOs that for some reason cannot generated normal
interrupts at all.

To support this we add a flag irq_need_valid_mask to struct gpio_chip. When
this flag is set the core allocates irq_valid_mask that holds one bit for
each GPIO the chip has. By default all bits are set but drivers can
manipulate this using set_bit() and clear_bit() accordingly.

Then when gpiochip_irqchip_add() is called, this mask is checked and all
GPIOs with bit is set are added to the IRQ domain created for the GPIO
chip.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The GPIOLIB is now selectable explicitly, and always available
for all archs. All archs that require GPIOLIB are switched to
select GPIOLIB directly. Delete the hairy ARCH_REQUIRE_GPIOLIB
and ARCH_WANTS_OPTIONAL_GPIOLIB Kconfig symbols.

Cc: Michael Büsch <m@bues.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Make the text clearer, remove reference to confusing "positive"
and "negative" and elaborate a bit.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This has been a totally undocumented feature for years so add some
generic concepts and documentation about open drain/source, include
some facts on how we now support for hardware.

Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The 'dev_id' parameter of the GPIO_LOOKUP{,_IDX} macros were removed by
commit ad824783fb23 ("gpio: better lookup method for platform GPIOs").

Update the documentation to reflect that.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This patch fix some spelling typos found in Documentation/gpio.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Pull documentation update from Jon Corbet:
 "There is a nice new document from Neil on how pathname lookups work
  and some new CAN driver documentation.  Beyond that, we have
  kernel-doc fixes, a bit more work to support reproducible builds, and
  the usual collection of small fixes"

* tag 'docs-for-linus' of git://git.lwn.net/linux: (34 commits)
  Documentation: add new description of path-name lookup.
  Documentation/vm/slub.txt: document slabinfo-gnuplot.sh
  Doc: ABI/stable: Fix typo in ABI/stable
  doc: Clarify that nmi_watchdog param is for hardlockups
  Typo correction for description in gpio document.
  DocBook: Fix kernel-doc to be case-insensitive for private:
  kernel-docs.txt: update kernelnewbies reference
  Doc:kvm: Fix typo in Doc/virtual/kvm
  Documentation/Changes: Add bc in "Current Minimal Requirements" section
  Documentation/email-clients.txt: remove trailing whitespace
  DocBook: Use a fixed encoding for output
  MAINTAINERS: The docs tree has moved
  Docs/kernel-parameters: Add earlycon devicetree usage
  SubmittingPatches: make Subject examples match the de facto standard
  Documentation: gpio: mention that <function>-gpio has been deprecated
  Documentation: cgroups: just fix a few typos
  Documentation: Update kselftest.txt
  Documentation: DMA API: Be more explicit that nents is always the same
  Documentation: Update the default value of crashkernel low
  zram: update documentation
  ...