How can i using GPIO like button in LINUX on OMAPL138

Mohamed EL BAB

Other Parts Discussed in Thread: OMAPL138

Hi,

How do I write code in C to create the pins for turning on a LED like the button reset or button user on OMAPL138 using linux.

Is there any example for this? what can i do for accessing the GPIO using LINUX in user space. and is there an application exactly for this work.

Thanks in adv

SiMo

over 12 years ago

0 Raja over 12 years ago

TI__Guru* 81335 points

Hi Mohamed EL BAB,

Welcome to the TI E2E forum. I hope you will find many good answers here and in the TI.com documents and in the TI Wiki Pages (for processor issues). Be sure to search those for helpful information and to browse for the questions others may have asked on similar topics (e2e.ti.com).

Please refer the below post. That completely answers your query.

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/p/270621/946703.aspx

0 Mohamed EL BAB over 12 years ago in reply to Raja

Prodigy 60 points

I was trying to write a GPIO driver module for omapl138 , in order to use the button Users 
or in IHM Qt  trying make a program for this.

I am using a OMAP L138 processor in linux, and am trying to find the base address of 
the physical address space to the Kernel's virtual address space. But I guess
I am not able to figure out the exact base address of the GPIO, 
for example in the JTAG header for ARM core in j23.

thanks for your response i saw it all this ansers but i 'm not find the well solution.

Mohamed

0 Raja over 12 years ago in reply to Mohamed EL BAB

TI__Guru* 81335 points

Hi Mohamed,

I hope you will be using the Linux kernel PSP released by TI.

If yes, you no need to write a separate GPIO driver for GPIO access.

It is handled in kernel. Please refer the below link to access GPIO from user space.

http://processors.wiki.ti.com/index.php/GPIO_Driver_Guide#User_Space_-_Sysfs_control

The above referred e2e thread has code snippet to configure/read/write the GPIO from user space.

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How can i using GPIO like button in LINUX on OMAPL138