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Commit 1ec5c186 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'gpio-v4.11-1' 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 v4.11 cycle

  Core changes:

   - Augment fwnode_get_named_gpiod() to configure the GPIO pin
     immediately after requesting it like all other APIs do. This is a
     treewide change also updating all users.

   - Pass a GPIO label down to gpiod_request() from
     fwnode_get_named_gpiod(). This makes debugfs and the userspace ABI
     correctly reflect the current in-kernel consumer of a pin taken
     using this abstraction. This is a treewide change also updating all
     users.

   - Rename devm_get_gpiod_from_child() to
     devm_fwnode_get_gpiod_from_child() to reflect the fact that this
     function is operating on a fwnode object. This is a treewide change
     also updating all users.

   - Make it possible to take multiple GPIOs in a single hog of device
     tree hogs.

   - The refactorings switching GPIO chips to use the .set_config()
     callback using standard pin control properties and providing a
     backend into the pin control subsystem that were also merged into
     the pin control tree naturally appear here too.

  Testing instrumentation:

   - A whole slew of cleanups and improvements to the mockup GPIO
     driver. We now have an extended userspace test exercising the
     subsystem, and we can inject interrupts etc from userspace to fully
     test the core GPIO functionality.

  New drivers:

   - New driver for the Cortina Systems Gemini GPIO controller.

   - New driver for the Exar XR17V352/354/358 chips.

   - New driver for the ACCES PCI-IDIO-16 PCI GPIO card.

  Driver changes:

   - RCAR: set the irqchip parent device, add fine-grained runtime PM
     support.

   - pca953x: support optional RESET control line on the chip.

   - DaVinci: cleanups and simplifications. Add support for multiple
     instances.

   - .set_multiple() and naming of lines on more or less all of the
     ISA/PCI GPIO controllers.

   - mcp23s08: refactored to use regmap as a first step to further
     rewrites and modernizations"

* tag 'gpio-v4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (61 commits)
  gpio: reintroduce devm_get_gpiod_from_child()
  gpio: pci-idio-16: Fix PCI BAR index
  gpio: pci-idio-16: Fix PCI device ID code
  gpio: mockup: implement event injecting over debugfs
  gpio: mockup: add a dummy irqchip
  gpio: mockup: implement naming the lines
  gpio: mockup: code shrink
  gpio: mockup: readability tweaks
  gpio: Add GPIO support for the ACCES PCI-IDIO-16
  gpio: Add the devm_fwnode_get_index_gpiod_from_child() helper
  gpio: Rename devm_get_gpiod_from_child()
  gpio: mcp23s08: Select REGMAP/REGMAP_I2C to fix build error
  gpio: ws16c48: Add support for GPIO names
  gpio: gpio-mm: Add support for GPIO names
  gpio: 104-idio-16: Add support for GPIO names
  gpio: 104-idi-48: Add support for GPIO names
  gpio: 104-dio-48e: Add support for GPIO names
  gpio: ws16c48: Remove unnecessary driver_data set
  gpio: gpio-mm: Remove unnecessary driver_data set
  gpio: 104-idio-16: Remove unnecessary driver_data set
  ...
parents d5dee39b 3498d869

Documentation/devicetree/bindings/gpio/cortina,gemini-gpio.txt

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+24 −0
Original line number Diff line number Diff line 
Cortina Systems Gemini GPIO Controller



Required properties:



- compatible : Must be "cortina,gemini-gpio"

- reg : Should contain registers location and length

- interrupts : Should contain the interrupt line for the GPIO block

- gpio-controller : marks this as a GPIO controller

- #gpio-cells : Should be 2, see gpio/gpio.txt

- interrupt-controller : marks this as an interrupt controller

- #interrupt-cells : a standard two-cell interrupt flag, see

  interrupt-controller/interrupts.txt



Example:



gpio@4d000000 {

	compatible = "cortina,gemini-gpio";

	reg = <0x4d000000 0x100>;

	interrupts = <22 IRQ_TYPE_LEVEL_HIGH>;

	gpio-controller;

	#gpio-cells = <2>;

	interrupt-controller;

	#interrupt-cells = <2>;

};

Documentation/devicetree/bindings/gpio/gpio-pca953x.txt

+4 −0
Original line number Diff line number Diff line
@@ -29,6 +29,10 @@ Required properties: 
	onsemi,pca9654

	exar,xra1202



Optional properties:

 - reset-gpios: GPIO specification for the RESET input. This is an

		active low signal to the PCA953x.



Example:

Documentation/devicetree/bindings/gpio/gpio.txt

+4 −4
Original line number Diff line number Diff line
@@ -187,10 +187,10 @@ gpio-controller's driver probe function. 


Each GPIO hog definition is represented as a child node of the GPIO controller.

Required properties:

- gpio-hog:   A property specifying that this child node represent a GPIO hog.

- gpios:      Store the GPIO information (id, flags, ...). Shall contain the

	      number of cells specified in its parent node (GPIO controller

	      node).

- gpio-hog:   A property specifying that this child node represents a GPIO hog.

- gpios:      Store the GPIO information (id, flags, ...) for each GPIO to

	      affect. Shall contain an integer multiple of the number of cells

	      specified in its parent node (GPIO controller node).

Only one of the following properties scanned in the order shown below.

This means that when multiple properties are present they will be searched

in the order presented below and the first match is taken as the intended

Documentation/gpio/driver.txt

+46 −9
Original line number Diff line number Diff line
@@ -41,34 +41,71 @@ In the gpiolib framework each GPIO controller is packaged as a "struct 
gpio_chip" (see linux/gpio/driver.h for its complete definition) with members

common to each controller of that type:



 - methods to establish GPIO direction

 - methods used to access GPIO values

 - method to return the IRQ number associated to a given GPIO

 - methods to establish GPIO line direction

 - methods used to access GPIO line values

 - method to set electrical configuration to a a given GPIO line

 - method to return the IRQ number associated to a given GPIO line

 - flag saying whether calls to its methods may sleep

 - optional line names array to identify lines

 - optional debugfs dump method (showing extra state like pullup config)

 - optional base number (will be automatically assigned if omitted)

 - label for diagnostics and GPIOs mapping using platform data

 - optional label for diagnostics and GPIO chip mapping using platform data



The code implementing a gpio_chip should support multiple instances of the

controller, possibly using the driver model. That code will configure each

gpio_chip and issue gpiochip_add(). Removing a GPIO controller should be rare;

use gpiochip_remove() when it is unavoidable.

gpio_chip and issue gpiochip_add[_data]() or devm_gpiochip_add_data().

Removing a GPIO controller should be rare; use [devm_]gpiochip_remove() when

it is unavoidable.



Most often a gpio_chip is part of an instance-specific structure with state not

Often a gpio_chip is part of an instance-specific structure with states not

exposed by the GPIO interfaces, such as addressing, power management, and more.

Chips such as codecs will have complex non-GPIO state.

Chips such as audio codecs will have complex non-GPIO states.



Any debugfs dump method should normally ignore signals which haven't been

requested as GPIOs. They can use gpiochip_is_requested(), which returns either

NULL or the label associated with that GPIO when it was requested.



RT_FULL: GPIO driver should not use spinlock_t or any sleepable APIs

RT_FULL: the GPIO driver should not use spinlock_t or any sleepable APIs

(like PM runtime) in its gpio_chip implementation (.get/.set and direction

control callbacks) if it is expected to call GPIO APIs from atomic context

on -RT (inside hard IRQ handlers and similar contexts). Normally this should

not be required.





GPIO electrical configuration

-----------------------------



GPIOs can be configured for several electrical modes of operation by using the

.set_config() callback. Currently this API supports setting debouncing and

single-ended modes (open drain/open source). These settings are described

below.



The .set_config() callback uses the same enumerators and configuration

semantics as the generic pin control drivers. This is not a coincidence: it is

possible to assign the .set_config() to the function gpiochip_generic_config()

which will result in pinctrl_gpio_set_config() being called and eventually

ending up in the pin control back-end "behind" the GPIO controller, usually

closer to the actual pins. This way the pin controller can manage the below

listed GPIO configurations.





GPIOs with debounce support

---------------------------



Debouncing is a configuration set to a pin indicating that it is connected to

a mechanical switch or button, or similar that may bounce. Bouncing means the

line is pulled high/low quickly at very short intervals for mechanical

reasons. This can result in the value being unstable or irqs fireing repeatedly

unless the line is debounced.



Debouncing in practice involves setting up a timer when something happens on

the line, wait a little while and then sample the line again, so see if it

still has the same value (low or high). This could also be repeated by a clever

state machine, waiting for a line to become stable. In either case, it sets

a certain number of milliseconds for debouncing, or just "on/off" if that time

is not configurable.





GPIOs with open drain/source support

------------------------------------

MAINTAINERS

+6 −0
Original line number Diff line number Diff line
@@ -265,6 +265,12 @@ L: linux-iio@vger.kernel.org 
S:	Maintained

F:	drivers/iio/counter/104-quad-8.c



ACCES PCI-IDIO-16 GPIO DRIVER

M:	William Breathitt Gray <vilhelm.gray@gmail.com>

L:	linux-gpio@vger.kernel.org

S:	Maintained

F:	drivers/gpio/gpio-pci-idio-16.c



ACENIC DRIVER

M:	Jes Sorensen <jes@trained-monkey.org>

L:	linux-acenic@sunsite.dk