Re: [PATCH] input: make gpio-keys use IRQF_SHARED

[Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>]

On Wed, Sep 16, 2009 at 8:28 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Wed, Sep 16, 2009 at 07:03:18PM +0400, Dmitry Eremin-Solenikov wrote:
>> There is nothing that disallows gpio-keys to share it's IRQ line
>> w/ other drivers. Make it use IRQF_SHARED in request_irq().
>>
>> An example of other driver with which I'd like to share IRQ line
>> for GPIO buttons is ledtrig-gpio.
>>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>> ---
>>  drivers/input/keyboard/gpio_keys.c |    1 +
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
>> index efed0c9..9fc2fab 100644
>> --- a/drivers/input/keyboard/gpio_keys.c
>> +++ b/drivers/input/keyboard/gpio_keys.c
>> @@ -147,6 +147,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
>>               }
>>
>>               error = request_irq(irq, gpio_keys_isr,
>> +                                 IRQF_SHARED |
>>                                   IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
>>                                   button->desc ? button->desc : "gpio_keys",
>>                                   bdata);
>
> How will you determine which device generated the interrupt? Because you
> can't return IRQ_HANDLED unconditionally and expect both devices work
> reliably.

It's a single device (gpio pin). However I'd like to be able to attach
several handlers to it.
E.g. one isr is gpio-keys (for reporting event to userspace), another
isr will be from
ledtrig-gpio (controlling the LED). Another can be some kind of
battery driver, etc.

All these drivers will provide different kinds of response for single GPIO pin.

-- 
With best wishes
Dmitry
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