Re: Configuring a TWL GPIO pin as an interrupt

[David Brownell <david-b@pacbell.net>]

On Friday 20 February 2009, Felipe Balbi wrote:
> On Fri, Feb 20, 2009 at 08:27:54PM -0600, Lopez Cruz, Misael wrote:
> > Hi,
> > 
> > I'm interested in bringing headset detection feature for audio. The
> > detection is done through TWL GPIO_2. How can I configure a GPIO pin
> > to generate an interrupt? Is there any API? Could you please point
> > out another driver using that functionality so I can use as reference?   

I don't think there is one.  I hacked my Beagleboard to test
those ... Rev B boards don't have EHCI, so GPIO-1 is easily
available.

In the setup() callback for the TWL4030 GPIOs:

{
  int GPIO_NUMBER = gpio_base + 2;

> gpio_request(GPIO_NUMBER, "Headset IRQ");
> gpio_direction_input(GPIO_NUMBER);

  lm8323_board_info.irq = gpio_to_irq(GPIO_NUMBER);
  ... something registers this board_info ...

  ...
  return 0;
}

and then later the lm8323 driver will use that IRQ:

> request_irq(client->irq, lm8323_irq, flags | IRQF_SHARED, DRIVER_NAME, dev);
> 
> that should do it :-)
> 
> see that GPIO_NUMBER will be gpio_base + 2, base is board-specific

..... and hence client->irq is also board-specific,
which is why it needs to be set up