[ELDK] GPIO pin in interrupt handler/AMCC processor

Stefan Roese sr at denx.de
Mon Feb 8 19:13:57 CET 2010

Hi Zoolu,

first, this question is not ELDK related. You should send it to Linux-PPC 
mailing list instead <linuxppc-dev at ozlabs.org>. But still here a few quick 

On Monday 08 February 2010 17:37:20 Zoolu R wrote:
> We are using a target with AMCC 440ep processor. We need to read the a GPIO
> pin  value in a interrupt mode in linux kernel. Is there some modules where
> i can refer so some generic implementation(configuring gpio pin as
>  inteerupt pin and handlling the same).

The PPC4xx GPIO support is available in the current Linux kernel. See:


for more details. Please note that you also need to write a GPIO device node 
in the device tree source (dts) of your Linux port. See this file for details 
in the GPIO node:


>  I would like to detect the dynamic
>  value change(0/1) using interrupt and perform isr_call back. Could some
>  one show me some pointers.

So you don't want to use the GPIO pin functionality, but the external 
interrupt functionality (the pin functions are multiplexed). You need to write 
a device driver for your custom device. And you need to configure the pin as 
external interrupt and again add a device node including the interrupt 
description into your device tree source (dts).


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