Re: [ELDK] GPIO pin in interrupt handler/AMCC processor

Hi Stefan,

thanks for you reply, as per Amcc 440 ep h/w spec . I can see 10 External
interrupts can be configured !! So can i use the GPIO ping mapped to one of
these external IRQ's ? Or should the h/w deisgn  also support it  or is it
pure s/w configurations. So i would just like to get an indication via
interrupt when status is changed (0/1). I would like to do this is linux.

Are there any reference drivers for this ? how to go about it ?

Thanks & Regards
Zoolu
On Mon, Feb 8, 2010 at 11:43 PM, Stefan Roese [off-list ref] wrote:

Hi Zoolu,

first, this question is not ELDK related. You should send it to Linux-PPC
mailing list instead [off-list ref]. But still here a few quick
answers/comments.

On Monday 08 February 2010 17:37:20 Zoolu R wrote:

quoted

We are using a target with AMCC 440ep processor. We need to read the a

GPIO

quoted

pin  value in a interrupt mode in linux kernel. Is there some modules

where

quoted

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:

arch/powerpc/sysdev/ppc4xx_gpio.c

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:

arch/powerpc/boot/dts/warp.dts

quoted

 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).

Cheers,
Stefan

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