[deliverable/linux.git] / Documentation / arm / Samsung / GPIO.txt

		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.
Commit	Line	Data
d192baea BD	1	Samsung GPIO implementation
	2	===========================
	3
	4	Introduction
	5	------------
	6
	7	This outlines the Samsung GPIO implementation and the architecture
98025c8c	8	specific calls provided alongside the drivers/gpio core.
d192baea BD	9
	10
	11	S3C24XX (Legacy)
	12	----------------
	13
	14	See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
98025c8c	15	about these devices. Their implementation has been brought into line
d192baea BD	16	with the core samsung implementation described in this document.
	17
	18
	19	GPIOLIB integration
	20	-------------------
	21
	22	The gpio implementation uses gpiolib as much as possible, only providing
	23	specific calls for the items that require Samsung specific handling, such
	24	as pin special-function or pull resistor control.
	25
	26	GPIO numbering is synchronised between the Samsung and gpiolib system.
	27
	28
	29	PIN configuration
	30	-----------------
	31
98025c8c	32	Pin configuration is specific to the Samsung architecture, with each SoC
d192baea BD	33	registering the necessary information for the core gpio configuration
	34	implementation to configure pins as necessary.
	35
	36	The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a
	37	driver or machine to change gpio configuration.
	38
	39	See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
	40	on these functions.