On 09/23/2013 10:15 PM, Linus Walleij wrote: > On Sun, Sep 22, 2013 at 4:40 PM, Javier Martinez Canillas > <javier.martinez@xxxxxxxxxxxxxxx> wrote: > >> To use a GPIO pin as an interrupt line, two previous configurations >> have to be made: >> >> a) Map the GPIO pin as an interrupt line into the Linux irq space >> b) Enable the GPIO bank and configure the GPIO direction as input >> >> Most GPIO/IRQ chip drivers just create a mapping for every single >> GPIO pin with irq_create_mapping() on .probe so users usually can >> assume a) and only have to do b) by using the following sequence: >> >> gpio_request(gpio, "foo IRQ"); >> gpio_direction_input(gpio); >> >> and then request a IRQ with: >> >> irq = gpio_to_irq(gpio); >> request_irq(irq, ...); > > I guess I have to live with this approach, but I'd like to - if possible - > address my pet issue. > > - It is OK that the HW get set up as GPIO input by the IRQ > request function alone. (Through gpio_irq_type I guess). > Yes, this is how is made on this patch indeed. > - When a second caller calls omap_gpio_request() it should > be OK as well, but only if the flags corresponds to the > previously enabled input mode. Else it should be > disallowed. > > - The same should happen for _set_gpio_direction() if a pin > previously set up for IRQ gets a request to be used as > output. > > If this cannot be tracked in the driver, it is certainly a candidate > for something that gpiolib should be doing. And then I'm open to > solutions to how we can do that. > Ok, this can be tracked in the driver, will add it when posting v2 soon. > If this needs to be applied pronto to fix the regression I'm > happy with that too, if we add a big boilerplate stating the above > problem and that it needs to be *fixed* at some point. > > But in either case I want this to be tested on OMAP1 before > I apply it, as in a Tested-by tag. > Agreed. Even though this is a fix for a long standing issue I prefer it to be tested extensively than applying the patch in a rush just to learn that causes regressions and have to be reverted as it happens last time. So as you said let's wait until we have a few Tested-by tags by people using different OMAP platforms specially OMAP1. > Yours, > Linus Walleij > Thanks a lot and best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
