gpio: devm_gpio_* support should not depend on GPIOLIB

Some architectures (e.g. blackfin) provide gpio API without requiring
GPIOLIB support (ARCH_WANT_OPTIONAL_GPIOLIB).  devm_gpio_* functions
should also work for these architectures, since they do not really
depend on GPIOLIB.

Add a new option GPIO_DEVRES (enabled by default) to control the build
of devres.c.  It also removes the empty version of devm_gpio_*
functions for !GENERIC_GPIO build from linux/gpio.h, and moves the
function declarations from asm-generic/gpio.h into linux/gpio.h.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

2 files changed, 5 insertions, 1 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 682de754d63f..d9729322b1c7 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -30,6 +30,9 @@ config ARCH_REQUIRE_GPIOLIB
           Selecting this from the architecture code will cause the gpiolib
           code to always get built in.
 
+config GPIO_DEVRES
+        def_bool y
+        depends on HAS_IOMEM
 
 
 menuconfig GPIOLIB
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c5aebd008dde..36ca605ff038 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -2,7 +2,8 @@
 
 ccflags-$(CONFIG_DEBUG_GPIO)    += -DDEBUG
 
-obj-$(CONFIG_GPIOLIB)           += gpiolib.o devres.o
+obj-$(CONFIG_GPIO_DEVRES)       += devres.o
+obj-$(CONFIG_GPIOLIB)           += gpiolib.o
 obj-$(CONFIG_OF_GPIO)           += gpiolib-of.o
 obj-$(CONFIG_GPIO_ACPI)         += gpiolib-acpi.o