linux-kernel - problems with GPIO

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Message-ID: <AANLkTikcC1o0zM5ChPhhvhbLPtCNzrtUJ7HCNHHGTcaU@mail.gmail.com>
Date:	Fri, 18 Feb 2011 13:21:28 +0900
From:	"Murali K. Vemuri" <vemuri.muralikrishna@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: problems with GPIO

Hi There,

I am rather a novice with linux kernel and I have this problem.
My board is  OMAP 3530 based and I use GPIO 21 to detect an external
device plug-in.
Now, when the board is just booted (after a complete power disconnect
), the GPIO is high, and when I plug in my external device, the GPIO
goes low, and I am able to detect it.
However, I see the voltage level still low after I remove the external
plug-in, and any further plug-ins, remain un-detected.
My H/W engineers say it is some config I am missing in Kernel.
can someone point me?

my code snippet is like:

    omap_mux_init_gpio(MY_GPIO,  OMAP_PIN_INPUT_PULLDOWN  );
    gpio_request(MY_GPIO,"CABLE IN");
    gpio_direction_input(MY_GPIO);
    gpio_set_value(MY_GPIO,1);

    set_irq_type(MY_IRQ,
            IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING
            );

    err = request_threaded_irq (MY_IRQ, NULL, my_dev_irq_thread,
           IRQF_TRIGGER_FALLING,
           "MY_DEV", NULL);

As I mentioned "my_dev_irq_thread" gets called when the actual GPIO is
detected to be going low.

Any pointers?
Thanks & regards
Murali
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