[uClinux-dev] Problem in attaching interrupt handlers to IRQ1-7 on a mcf5475 supportedboard having uclinux ported on it

[Juanba Romance Gallego]

> Dear all,
>
> I am trying to attach my interrupt handler to any of irq1-7. but i am
> unsuccessful in doing that. My cpu board is having mcf5475 processor and is
> running on uclinux , linux kernel-2.4.x. I also tried to attach my code to
> the already connected isr. but i was unable to find where exactly in the
> directory structure are the interrupt handlers located.
>
> Can anyone plz tell me how to go about these 2 issues.
IHTH

You have to write somethings yourself. Let me note some hints

1.- uClinux only provides irq drivers to manage its supported devices and the 
system tick, both of them are items of p u b l i c interest, so a resources 
framework is developed to be programmed/tested/published 

2.- uClinux (as standard Linux) provides the typical "request_irq" symbol to 
register/unregister a custom isr into the interrupt vector table. It means 
the uClinux OS coders gives you software to "store cpu/stack context, the 
jumptomyservcice and the restore the stuff". Nothing else.. you have to be 
quite confidence about the performance of your "interrupts" environment, 
maybe some uClinux policies are not suitable for you stuff, this is your 
choice/exam..

3.- The external interrupts of any machine are not (of course) public/common 
domain. So any software is/could be provided. You should read the chapter 14 
related with the EDGE port where whatever MCFxxxx maps the external 
interrupts (Motorola policy). Before write any code line you should 
understand how this tricky matter works and what what/how you need to program 
it..
  
4.- The Chapter 13.(Interrupt controller) of your processor describes how the 
vectors are mapped into your machine same as other MCF machines, which 
register/flags you should clear/set and so forth.. 

As general policy you should use the drivers set ported to uclinux-MCFxxx as 
examples about how to install your own stuff/application 
 
>
> Is it that when these pins are configured in GPIO mode then interrupt
> handlers are not called? but i can notice the output on my hyper terminal
> when ever i ground the irq7 pins on my board. the o/p is like this -
>
> "GPIO value = 7
> status = FFFF"
>
> When i ground irq6 pins on my board, then o/p is very similar -
> "GPIO value = 6
> status = FFFF"

5.- Review also the pin assignment for the edge port sure you have to 
verify/review the function. Any modern/respectable micro-controller-processor 
have multiplexed functions mapped into the i/o pines and their never are like 
the application need.

>
>
> What exactly is happening, if these pins are configured in GPIO mode by
> uclinux, then where from these o/p is coming. Which handler is giving that?
>
> Or, the situation is entirely different than whatever i am thinking.?
> Please help me out guys.........!
> Regards and thanx.
> Rahul.

This is my current understanding of this stuff, may i be wrong for any 
appreciation please guys apply the corrections if any 

Best regards..