Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> writes: > On Tue, Sep 22, 2009 at 05:14:22PM +0200, Ferenc Wagner wrote: >> Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> writes: >> >>> 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@xxxxxxxxx> >>>> --- >>>> 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 would be possible, but commit >> da0d03fe6cecde837f113a8a587f5a872d0fade0 states that: >> >> The gpio_get_value function may sleep, so it should not be called in a >> timer function. >> >> But I don't see why it could sleep, is that really the case? > > There are things like i2c gpio extenders that require access to slow > buses and can't sleep. I assume you mean "can sleep". Please read my other reply in this thread before the following. All this seems to mean that using level triggered interrupts on such devices is impossible, unless we find a way to acknowledge the interrupt without GPIO access. But level triggering is needed for sharing. Maybe we could make this configurable on a per-button basis? Or by a module parameter? Anyway, a gpio_cansleep test should go into the module initialisation routine. >> Also, commit 57ffe9d539e0eb741bb9ca8f2834d210e70ee2e3 removed the >> possibility of telling apart different keys, so that should be >> reverted during the process. I already asked Uwe Kleine-König >> about the whys, but didn't get a reply. > > I don't see why you say that... You request IRQ per button and you get > that button structure as argument in the interrupt handler. In practice, several buttons often share a single IRQ line, possibly even with other hardware, like the serial port in my case (as described in my other reply). So generally you need the full platform data for all GPIO buttons in the handler, to find out which generated the interrupt. -- Thanks, Feri. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
