GPIO Driver Access in sitara linux

Hemanth Tenkodu

Other Parts Discussed in Thread: AM3354

Hi,

I am using AM3354 Cortex A8 MCU with sitara Linux. I am able to make the system up with the uImage and able to run the test.0 compiled by a test.c file with "hello word" printf.

Now I would like to use driver layer calls from this test application file. Please provide some guidelines

I searched in the INTERNET and found that all the driver classes are provided in the /sys/class location of the file system.

I would like to know the GPIO's available in AM3354 MCU and corresponding driver functions in the TI Linux distribution.

Please help!

Regards,

Hemanth

over 12 years ago

0 Dave Gerlach over 12 years ago

TI__Intellectual 1830 points

Hi Hemanth,

Please check out this page on the wiki that covers the GPIO Linux Driver: http://processors.wiki.ti.com/index.php/GPIO_Driver_Guide.

It contains information about using the GPIOs from within user space and kernel space. Please keep in mind that many pins already serve other functions so there will be pins you can not use as GPIOs.

Regards,

Dave

0 Hemanth Tenkodu over 12 years ago

Prodigy 180 points

Hi, I found very useful information at the below link. It has answered most of the questions asked in my previous query.

http://processors.wiki.ti.com/index.php/GPIO_Driver_Guide

But an example program would be of great help.

Can someone please provide a example code to toggle a AM3354 GPIO?

Also I would like to write socket programming in my application, please provide some useful documentation and example code for the same.

Regards,

Hemanth

0 Hemanth Tenkodu over 12 years ago in reply to Dave Gerlach

Prodigy 180 points

Dear Dave,

Please explain more on the GPIO usage, how to know whether the GPIO is already used or available. Are these GPIO pins are multiplexed with other peripheral functionalities? If so how to change the mode of the bank from the sysfs functionality?

Regards,

Hemanth

0 Dave Gerlach over 12 years ago in reply to Hemanth Tenkodu

TI__Intellectual 1830 points

Hemanth,

I do not know of an example application that uses the GPIOs from within Linux. As for socket programming, any standard Linux example for this will work on the SDK, the POSIX sockets API is the same as on many other Linux distributions.

You can find more information about modifying the pinmux settings here: http://processors.wiki.ti.com/index.php/AM335x_PSP_User%27s_Guide#Modifying_Pin_Mux_settings

Regards,

Dave

0 sviss over 12 years ago in reply to Dave Gerlach

Expert 1530 points

Please look at:

ti-sdk-am335x-xxx/board-support/linux-xxx-psp.xx.xx.xx/Documentation/gpio.txt

and

https://groups.google.com/forum/?fromgroups=#!topic/beagleboard/Xru8FrOfvP4

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GPIO Driver Access in sitara linux