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authorDavid Brownell <dbrownell@users.sourceforge.net>2008-02-04 22:28:17 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:12 -0800
commita9c5fff542544c8595bb12efeb278a96d99386fc (patch)
tree28683c259e73f2f74d140b29ac3a9c3c1491e7a3 /drivers/gpio
parent99c84dbdc73d158a1ab955a4a5f74c18074796a3 (diff)
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>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/Kconfig32
-rw-r--r--drivers/gpio/Makefile4
2 files changed, 36 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
new file mode 100644
index 00000000000..560687c4667
--- /dev/null
+++ b/drivers/gpio/Kconfig
@@ -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
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
new file mode 100644
index 00000000000..369e4fc432e
--- /dev/null
+++ b/drivers/gpio/Makefile
@@ -0,0 +1,4 @@
+# gpio support: dedicated expander chips, etc
+
+ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG
+