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authorLinus Walleij <linus.walleij@linaro.org>2016-04-19 13:40:17 +0200
committerLinus Walleij <linus.walleij@linaro.org>2016-08-08 09:50:00 +0200
commit65053e1a7743e282c3dd08d3d435ac8b746f5359 (patch)
tree2842466eec6df6d413be4c79efce384b758e18d3 /Documentation/gpio
parent10e59a648812e380e6bee93f1218c9199fe84de2 (diff)
downloadlinux-65053e1a7743e282c3dd08d3d435ac8b746f5359.tar.bz2
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: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/gpio')
-rw-r--r--Documentation/gpio/board.txt6
-rw-r--r--Documentation/gpio/gpio-legacy.txt16
2 files changed, 7 insertions, 15 deletions
diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt
index 86d3fa95fd12..40884c4fe40c 100644
--- a/Documentation/gpio/board.txt
+++ b/Documentation/gpio/board.txt
@@ -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.
diff --git a/Documentation/gpio/gpio-legacy.txt b/Documentation/gpio/gpio-legacy.txt
index 79ab5648d69b..b34fd94f7089 100644
--- a/Documentation/gpio/gpio-legacy.txt
+++ b/Documentation/gpio/gpio-legacy.txt
@@ -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.