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authorBen Dooks <ben-linux@fluff.org>2010-05-24 07:13:30 +0400
committerBen Dooks <ben-linux@fluff.org>2010-05-28 14:31:31 +0400
commitd192baeaa7a068b4e5151a34b4121d99938e396d (patch)
treeb32e615deb177edd1d673dde9faebea43447c44d /Documentation/arm/Samsung/GPIO.txt
parent941439267820c6811f44f247caefe823d4e4f5cd (diff)
downloadlinux-d192baeaa7a068b4e5151a34b4121d99938e396d.tar.xz
ARM: SAMSUNG: Documentation: add documentation on GPIO code
Add some documentation in Documentation/arm/Samsung for the GPIO code and where to look for the necessary functions. Update the S3C24XX case as well. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'Documentation/arm/Samsung/GPIO.txt')
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diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt
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+ Samsung GPIO implementation
+ ===========================
+
+Introduction
+------------
+
+This outlines the Samsung GPIO implementation and the architecture
+specfic calls provided alongisde the drivers/gpio core.
+
+
+S3C24XX (Legacy)
+----------------
+
+See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
+about these devices. Their implementation is being brought into line
+with the core samsung implementation described in this document.
+
+
+GPIOLIB integration
+-------------------
+
+The gpio implementation uses gpiolib as much as possible, only providing
+specific calls for the items that require Samsung specific handling, such
+as pin special-function or pull resistor control.
+
+GPIO numbering is synchronised between the Samsung and gpiolib system.
+
+
+PIN configuration
+-----------------
+
+Pin configuration is specific to the Samsung architecutre, with each SoC
+registering the necessary information for the core gpio configuration
+implementation to configure pins as necessary.
+
+The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a
+driver or machine to change gpio configuration.
+
+See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
+on these functions.
+
+