Hi,

Where can i get GPIO driver for AT91SAM9G45-EKES kit? is it part of the Kernel source?
When i checks out Kernel source, they have Sysfs implementation but i need a char driver (normal way). Can anyone please help me on this?

Thanks
Prashanth

[quote="pkumarn"]Hi,

Where can i get GPIO driver for AT91SAM9G45-EKES kit? is it part of the Kernel source?
When i checks out Kernel source, they have Sysfs implementation but i need a char driver (normal way). Can anyone please help me on this?
[/quote]

Sysfs implementation of GPIO is an excellent way, however you could be interested to discover how to manage GPIO access from user space.
In this case I suggest you to read the devmem2 source code, maybe using it as skeleton for your custom GPIO management.
ftp://ftp.koansoftware.com/public/linux ... /devmem2.c

HTH

Thanks for the reply. I am not much aware of Sysfs and i feel if you want to manager more GPIO's then it would be cumbersome (correct me if i am wrong). As i am comfortable in legacy way so was seeing if we have handy GPIO driver. When i talked to Atmel folks, they did provide me a GPIO driver but somehow it is not working. i am attaching the GPIO driver code and the application i have written to access the same. Can you please review and let me know what is wrong?

Thanks
Prashanth

[quote="pkumarn"]Thanks for the reply. I am not much aware of Sysfs and i feel if you want to manager more GPIO's then it would be cumbersome (correct me if i am wrong). As i am comfortable in legacy way so was seeing if we have handy GPIO driver. When i talked to Atmel folks, they did provide me a GPIO driver but somehow it is not working. i am attaching the GPIO driver code and the application i have written to access the same. Can you please review and let me know what is wrong?
[/quote]

What is not working?
Did you build sources?
Did you insmod the driver?
Did you launch the gpioutil 'tester'?
Please post your output and more info.

Here is what I did…
Compiled the module separately and flashed into the board
Then did insmod cdrv.ko – This operation was successful and was able to see the device “key” in /proc/devices
Then created new device at /dev using mknod /dev/key c 252 0 – Even this was successful
Then I ran “gpioutil” and this was able to open the device file successfully.
Once I do a “ioctl” call to Turn OFF or Turn ON a LED, I don’t see anything happening on the screen.
To make sure low level calls provide by Atmel are working, I put the following call in module initialization
at91_led_on() , even this failed.
I also put printk() in “ioctl” as the first statement, even this failed…
I am not sure what is wrong now ….

-Prashanth

Hi, for inputs, we have done something which consists on monitoring GPIO event on a specific file "/dev/gpio-event" on G45-EKES. A module is launch with IO to monitor and when a IO is modified we have an information .

Take a look here : http://wiki.gumstix.org/index.php?title=GPIO

For ouput, you only need to write to /sys/class/gpio/xxx, which is really easy.


If you have trouble , tell me, I'll try to help you more .
Regards
Seb