summaryrefslogtreecommitdiff
path: root/Documentation/arm/Samsung/GPIO.txt
blob: 513f2562c1a3162af49dc01fdb44780b9076b51b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
		Samsung GPIO implementation
		===========================

Introduction
------------

This outlines the Samsung GPIO implementation and the architecture
specific 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.