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Commit 65053e1a authored by Linus Walleij's avatar Linus Walleij
Browse files

gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB 



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: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 10e59a64

Documentation/gpio/board.txt

+3 −3
Original line number Diff line number Diff line
@@ -8,9 +8,9 @@ gpio-legacy.txt (actually, there is no real mapping possible with the old 
interface; you just fetch an integer from somewhere and request the

corresponding GPIO.



Platforms that make use of GPIOs must select ARCH_REQUIRE_GPIOLIB (if GPIO usage

is mandatory) or ARCH_WANT_OPTIONAL_GPIOLIB (if GPIO support can be omitted) in

their Kconfig. Then, how GPIOs are mapped depends on what the platform uses to

All platforms can enable the GPIO library, but if the platform strictly

requires GPIO functionality to be present, it needs to select GPIOLIB from its

Kconfig. Then, how GPIOs are mapped depends on what the platform uses to

describe its hardware layout. Currently, mappings can be defined through device

tree, ACPI, and platform data.

Documentation/gpio/gpio-legacy.txt

+4 −12
Original line number Diff line number Diff line
@@ -72,8 +72,8 @@ in this document, but drivers acting as clients to the GPIO interface must 
not care how it's implemented.)



That said, if the convention is supported on their platform, drivers should

use it when possible.  Platforms must select ARCH_REQUIRE_GPIOLIB or

ARCH_WANT_OPTIONAL_GPIOLIB in their Kconfig.  Drivers that can't work without

use it when possible.  Platforms must select GPIOLIB if GPIO functionality

is strictly required.  Drivers that can't work without

standard GPIO calls should have Kconfig entries which depend on GPIOLIB.  The

GPIO calls are available, either as "real code" or as optimized-away stubs,

when drivers use the include file:
@@ -553,22 +553,14 @@ either NULL or the label associated with that GPIO when it was requested. 


Platform Support

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

To support this framework, a platform's Kconfig will "select" either

ARCH_REQUIRE_GPIOLIB or ARCH_WANT_OPTIONAL_GPIOLIB

and arrange that its <asm/gpio.h> includes <asm-generic/gpio.h> and defines

three functions: gpio_get_value(), gpio_set_value(), and gpio_cansleep().

To force-enable this framework, a platform's Kconfig will "select" GPIOLIB,

else it is up to the user to configure support for GPIO.



It may also provide a custom value for ARCH_NR_GPIOS, so that it better

reflects the number of GPIOs in actual use on that platform, without

wasting static table space.  (It should count both built-in/SoC GPIOs and

also ones on GPIO expanders.



ARCH_REQUIRE_GPIOLIB means that the gpiolib code will always get compiled

into the kernel on that architecture.



ARCH_WANT_OPTIONAL_GPIOLIB means the gpiolib code defaults to off and the user

can enable it and build it into the kernel optionally.



If neither of these options are selected, the platform does not support

GPIOs through GPIO-lib and the code cannot be enabled by the user.

drivers/gpio/Kconfig

+0 −21
Original line number Diff line number Diff line
@@ -10,27 +10,6 @@ config ARCH_HAVE_CUSTOM_GPIO_H 
	  overriding the default implementations.  New uses of this are

	  strongly discouraged.



config ARCH_WANT_OPTIONAL_GPIOLIB

	bool

	help

	  Select this config option from the architecture Kconfig, if

	  it is possible to use gpiolib on the architecture, but let the

	  user decide whether to actually build it or not.

	  Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does

	  not depend on GPIOs being available, but rather let the user

	  decide whether he needs it or not.



config ARCH_REQUIRE_GPIOLIB

	bool

	select GPIOLIB

	help

	  Platforms select gpiolib if they use this infrastructure

	  for all their GPIOs, usually starting with ones integrated

	  into SOC processors.

	  Selecting this from the architecture code will cause the gpiolib

	  code to always get built in.





menuconfig GPIOLIB

	bool "GPIO Support"

	select ANON_INODES