REQUEST_IRQ fails when tried to register an IRQ for GPIO[OMAP L138]

Same driver code is able to do  register IRQ for other INTERRUPT lines :-

I have checked for :-

 1) 91 Upp

2) 14EMIF 

3) INTERRUPT NUMBER 2 ...

4) INTERRUPT NUMBER 51

For all the above i could see an entry in /proc/interrupts ....

But it fails for any interrupt between [42 - 50 ] That is GPIO Interrupt's .....

Can any one please guide me , if i need to follow some other mechanism to register INTERRUPT ISR for GPIO interrupt ......

Thanks 

Ashish:

Before requesting irq, we have to call,

gpio_to_irq function with gpio pin as argument,

you are doing that step?

Regards,

santosh vastrad

Hi Santosh , 

No i was not using that function . I was directly registering the INTERRUPT using REQUEST_IRQ. 

a) Is it compulsory that i should use this function i.e GPIO_TO_IRQ to resister GPIO interrupt ? 

     Is it like LINUX default mechanism of REQUEST_IRQ wont work for GPIO stuff .Hence for IRQ , we need to get the IRQ using 

    GPIO_TO_IRQ first and then use this as an parameter to REQUEST_IRQ.

b) Also apart from GPIO configuration , do i need to configure ARM INTERRUPT CONTROLLER to use GPIO an as interrupt 

    Or is it like we just have to configure GPIO . No need to configue any other stuff. 

c) I am not clear for point [b] , but what i understood is we have have to configure ARM interrupt controller apart from GPIO. 

     I am listing my understanding to how i was planning to register the GPIO interrupt :-

     a) I wanted to use GPIO6[2] as an interrupt pin. Hence from TRM i got that on ARM INTERRUPT controller 

          Interrupt number 48 is from GPIO Bank6. Hence i was registering ISR directly on this number. 

          [ Will try with GPIO_TO_IRQ and will update by today evening]. 

     b) Then i was planning to do following configuration for ARM INTERRUPT CONTROLLER  :-

          1. Enable GLOBAL INTERRUPT from GER register.

          2. ENABLE HOST Interrupt from HIER 

          3. MAP the GPIO Bank 6 interrupt to ARM CONTROLLER CHANNEL using CHAN12 [ As GPIO Bank 6 interrupt is 48]

          4. ENABLE SYSTEM Interrupt from ESR2 [ As i need for GPIO bank 6 , for which interrupt is 48]

          5. Then MONITOR  the INTERRUPT using SECR2 [ To check if interrupt has ocurred] 

                If interrupt has occurred clear the BIT in SECR2 by writing a 1 to corresponding bit. 

          6. Also for testing purpose or we can say simulation , i was planning to write 1 to corresponding bit of SECR2

              So that , even without HARDWARE INTERRUPT SIGNAL , i can check the functionality.

c) So can you please let me know if my understanding is correct or i am missing any details. 

d) Also befpre this we have to configure GPIO parameters for DIRECTION and TYPE of INTERRUPT sensing 

     like rising or falling edge ....

Please help me to figure out the correct mechanism to use GPIO as an interrupt .

I am working on this stuff for the first time , hence not very sure if my understanding is correct ....

Thanks

Ashish

Dear Santosh , 

It worked without much pain . Thanks for the GUIDANCE. 

Thank you,

Ashish