gpiolib: add drivers/gpio directory

Add an empty drivers/gpio directory for gpiolib infrastructure and GPIO
expanders.  It will be populated by later patches.

This won't be the only place to hold such gpio_chip code.  Many external chips
add a few GPIOs as secondary functionality (such as MFD drivers) and platform
code frequently needs to closely integrate GPIO and IRQ support.

This is placed *early* in the build/link sequence since it's common for other
drivers to depend on GPIOs to do their work, so they must be initialized early
in the device_initcall() sequence.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell 2008-02-04 22:28:17 -08:00 committed by Linus Torvalds
parent 99c84dbdc7
commit a9c5fff542
5 changed files with 41 additions and 0 deletions

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@ -1122,6 +1122,8 @@ source "drivers/i2c/Kconfig"
source "drivers/spi/Kconfig"
source "drivers/gpio/Kconfig"
source "drivers/w1/Kconfig"
source "drivers/power/Kconfig"

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@ -52,6 +52,8 @@ source "drivers/i2c/Kconfig"
source "drivers/spi/Kconfig"
source "drivers/gpio/Kconfig"
source "drivers/w1/Kconfig"
source "drivers/power/Kconfig"

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@ -5,6 +5,7 @@
# Rewritten to use lists instead of if-statements.
#
obj-$(CONFIG_HAVE_GPIO_LIB) += gpio/
obj-$(CONFIG_PCI) += pci/
obj-$(CONFIG_PARISC) += parisc/
obj-$(CONFIG_RAPIDIO) += rapidio/

32
drivers/gpio/Kconfig Normal file
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@ -0,0 +1,32 @@
#
# GPIO infrastructure and expanders
#
config HAVE_GPIO_LIB
bool
help
Platforms select gpiolib if they use this infrastructure
for all their GPIOs, usually starting with ones integrated
into SOC processors.
menu "GPIO Support"
depends on HAVE_GPIO_LIB
config DEBUG_GPIO
bool "Debug GPIO calls"
depends on DEBUG_KERNEL
help
Say Y here to add some extra checks and diagnostics to GPIO calls.
The checks help ensure that GPIOs have been properly initialized
before they are used and that sleeping calls aren not made from
nonsleeping contexts. They can make bitbanged serial protocols
slower. The diagnostics help catch the type of setup errors
that are most common when setting up new platforms or boards.
# put expanders in the right section, in alphabetical order
comment "I2C GPIO expanders:"
comment "SPI GPIO expanders:"
endmenu

4
drivers/gpio/Makefile Normal file
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@ -0,0 +1,4 @@
# gpio support: dedicated expander chips, etc
ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG