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>
This commit is contained in:
Ben Dooks 2010-05-24 12:13:30 +09:00
parent 9414392678
commit d192baeaa7
3 changed files with 48 additions and 0 deletions

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@ -12,6 +12,8 @@ Introduction
of the s3c2410 GPIO system, please read the Samsung provided
data-sheet/users manual to find out the complete list.
See Documentation/arm/Samsung/GPIO.txt for the core implemetation.
GPIOLIB
-------

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@ -218,6 +218,10 @@ GPIO
As of v2.6.34, the move towards using gpiolib support is almost
complete, and very little of the old calls are left.
See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific
support and Documentation/arm/Samsung/GPIO.txt for the core Samsung
implementation.
Clock Management
----------------

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@ -0,0 +1,42 @@
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.