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Commit 06b49ea4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'gpio-v3.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio 

Pull GPIO update from Linus Walleij:
 "This is the bulk of GPIO changes for the v3.17 development cycle, and
  this time we got a lot of action going on and it will continue:

   - The core GPIO library implementation has been split up in three
     different files:
     - gpiolib.c for the latest and greatest and shiny GPIO library code
       using GPIO descriptors only
     - gpiolib-legacy.c for the old integer number space API that we are
       phasing out gradually
     - gpiolib-sysfs.c for the sysfs interface that we are not entirely
       happy with, but has to live on for ABI compatibility

   - Add a flags argument to *gpiod_get* functions, with some
     backward-compatibility macros to ease transitions.  We should have
     had the flags there from the beginning it seems, now we need to
     clean up the mess.  There is a plan on how to move forward here
     devised by Alexandre Courbot and Mark Brown

   - Split off a special <linux/gpio/machine.h> header for the board
     gpio table registration, as per example from the regulator
     subsystem

   - Start to kill off the return value from gpiochip_remove() by
     removing the __must_check attribute and removing all checks inside
     the drivers/gpio directory.  The rationale is: well what were we
     supposed to do if there is an error code? Not much: print an error
     message.  And gpiolib already does that.  So make this function
     return void eventually

   - Some cleanups of hairy gpiolib code, make some functions not to be
     used outside the library private and make sure they are not
     exported, remove gpiod_lock/unlock_as_irq() as the existing
     function is for driver-internal use and fine as it is, delete
     gpio_ensure_requested() as it is not meaningful anymore

   - Support the GPIOF_ACTIVE_LOW flag from gpio_request_one() function
     calls, which is logical since this is already supported when
     referencing GPIOs from e.g. device trees

   - Switch STMPE, intel-mid, lynxpoint and ACPI (!) to use the gpiolib
     irqchip helpers cutting down on GPIO irqchip boilerplate a bit more

   - New driver for the Zynq GPIO block

   - The usual incremental improvements around a bunch of drivers

   - Janitorial syntactic and semantic cleanups by Jingoo Han, and
     Rickard Strandqvist especially"

* tag 'gpio-v3.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (37 commits)
  MAINTAINERS: update GPIO include files
  gpio: add missing includes in machine.h
  gpio: add flags argument to gpiod_get*() functions
  MAINTAINERS: Update Samsung pin control entry
  gpio / ACPI: Move event handling registration to gpiolib irqchip helpers
  gpio: lynxpoint: Convert to use gpiolib irqchip
  gpio: split gpiod board registration into machine header
  gpio: remove gpio_ensure_requested()
  gpio: remove useless check in gpiolib_sysfs_init()
  gpiolib: Export gpiochip_request_own_desc and gpiochip_free_own_desc
  gpio: move gpio_ensure_requested() into legacy C file
  gpio: remove gpiod_lock/unlock_as_irq()
  gpio: make gpiochip_get_desc() gpiolib-private
  gpio: simplify gpiochip_export()
  gpio: remove export of private of_get_named_gpio_flags()
  gpio: Add support for GPIOF_ACTIVE_LOW to gpio_request_one functions
  gpio: zynq: Clear pending interrupt when enabling a IRQ
  gpio: drop retval check enforcing from gpiochip_remove()
  gpio: remove all usage of gpio_remove retval in driver/gpio
  devicetree: Add Zynq GPIO devicetree bindings documentation
  ...
parents 664fb230 bdc6e95e

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

0 → 100644
+26 −0
Original line number Diff line number Diff line 
Xilinx Zynq GPIO controller Device Tree Bindings

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



Required properties:

- #gpio-cells 		: Should be two

			  - First cell is the GPIO line number

			  - Second cell is used to specify optional

			    parameters (unused)

- compatible		: Should be "xlnx,zynq-gpio-1.0"

- clocks		: Clock specifier (see clock bindings for details)

- gpio-controller	: Marks the device node as a GPIO controller.

- interrupts		: Interrupt specifier (see interrupt bindings for

			  details)

- interrupt-parent	: Must be core interrupt controller

- reg			: Address and length of the register set for the device



Example:

	gpio@e000a000 {

		#gpio-cells = <2>;

		compatible = "xlnx,zynq-gpio-1.0";

		clocks = <&clkc 42>;

		gpio-controller;

		interrupt-parent = <&intc>;

		interrupts = <0 20 4>;

		reg = <0xe000a000 0x1000>;

	};

Documentation/gpio/board.txt

+1 −1
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ Platform Data 
Finally, GPIOs can be bound to devices and functions using platform data. Board

files that desire to do so need to include the following header:



	#include <linux/gpio/driver.h>

	#include <linux/gpio/machine.h>



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:

Documentation/gpio/consumer.txt

+20 −6
Original line number Diff line number Diff line
@@ -29,13 +29,24 @@ gpiod_get() functions. Like many other kernel subsystems, gpiod_get() takes the 
device that will use the GPIO and the function the requested GPIO is supposed to

fulfill:



	struct gpio_desc *gpiod_get(struct device *dev, const char *con_id)

	struct gpio_desc *gpiod_get(struct device *dev, const char *con_id,

				    enum gpiod_flags flags)



If a function is implemented by using several GPIOs together (e.g. a simple LED

device that displays digits), an additional index argument can be specified:



	struct gpio_desc *gpiod_get_index(struct device *dev,

					  const char *con_id, unsigned int idx)

					  const char *con_id, unsigned int idx,

					  enum gpiod_flags flags)



The flags parameter is used to optionally specify a direction and initial value

for the GPIO. Values can be:



* GPIOD_ASIS or 0 to not initialize the GPIO at all. The direction must be set

  later with one of the dedicated functions.

* GPIOD_IN to initialize the GPIO as input.

* GPIOD_OUT_LOW to initialize the GPIO as output with a value of 0.

* GPIOD_OUT_HIGH to initialize the GPIO as output with a value of 1.



Both functions return either a valid GPIO descriptor, or an error code checkable

with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned
@@ -46,11 +57,13 @@ errors and an absence of GPIO for optional GPIO parameters. 


Device-managed variants of these functions are also defined:



	struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id)

	struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id,

					 enum gpiod_flags flags)



	struct gpio_desc *devm_gpiod_get_index(struct device *dev,

					       const char *con_id,

					       unsigned int idx)

					       unsigned int idx,

					       enum gpiod_flags flags)



A GPIO descriptor can be disposed of using the gpiod_put() function:
@@ -67,8 +80,9 @@ Using GPIOs 


Setting Direction

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

The first thing a driver must do with a GPIO is setting its direction. This is

done by invoking one of the gpiod_direction_*() functions:

The first thing a driver must do with a GPIO is setting its direction. If no

direction-setting flags have been given to gpiod_get*(), this is done by

invoking one of the gpiod_direction_*() functions:



	int gpiod_direction_input(struct gpio_desc *desc)

	int gpiod_direction_output(struct gpio_desc *desc, int value)

Documentation/gpio/driver.txt

+23 −2
Original line number Diff line number Diff line
@@ -157,13 +157,34 @@ Locking IRQ usage 
Input GPIOs can be used as IRQ signals. When this happens, a driver is requested

to mark the GPIO as being used as an IRQ:



	int gpiod_lock_as_irq(struct gpio_desc *desc)

	int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)



This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock

is released:



	void gpiod_unlock_as_irq(struct gpio_desc *desc)

	void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)



When implementing an irqchip inside a GPIO driver, these two functions should

typically be called in the .startup() and .shutdown() callbacks from the

irqchip.





Requesting self-owned GPIO pins

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



Sometimes it is useful to allow a GPIO chip driver to request its own GPIO

descriptors through the gpiolib API. Using gpio_request() for this purpose

does not help since it pins the module to the kernel forever (it calls

try_module_get()). A GPIO driver can use the following functions instead

to request and free descriptors without being pinned to the kernel forever.



	int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)



	void gpiochip_free_own_desc(struct gpio_desc *desc)



Descriptors requested with gpiochip_request_own_desc() must be released with

gpiochip_free_own_desc().



These functions must be used with care since they do not affect module use

count. Do not use the functions to request gpio descriptors not owned by the

calling driver.

MAINTAINERS

+3 −4
Original line number Diff line number Diff line
@@ -4031,7 +4031,8 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git 
S:	Maintained

F:	Documentation/gpio/

F:	drivers/gpio/

F:	include/linux/gpio*

F:	include/linux/gpio/

F:	include/linux/gpio.h

F:	include/asm-generic/gpio.h



GRE DEMULTIPLEXER DRIVER
@@ -7002,9 +7003,7 @@ M: Thomas Abraham <thomas.abraham@linaro.org> 
L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

L:	linux-samsung-soc@vger.kernel.org (moderated for non-subscribers)

S:	Maintained

F:	drivers/pinctrl/pinctrl-exynos.*

F:	drivers/pinctrl/pinctrl-s3c*

F:	drivers/pinctrl/pinctrl-samsung.*

F:	drivers/pinctrl/samsung/



PIN CONTROLLER - ST SPEAR

M:	Viresh Kumar <viresh.linux@gmail.com>