GPIO.txt
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Samsung GPIO implementation
===========================
Introduction
------------
This outlines the Samsung GPIO implementation and the architecture
specific calls provided alongside the drivers/gpio core.
S3C24XX (Legacy)
----------------
See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
about these devices. Their implementation has been 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 architecture, 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.