On 11/29/2013 02:42 PM, Linus Walleij wrote: > On Fri, Nov 29, 2013 at 11:45 AM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: >> On 11/29/2013 11:37 AM, Linus Walleij wrote: > (...) >>> Specifically you should be able to request an IRQ from the irq_chip >>> portions of the driver without first requesting the GPIO line. >>> >>> Some drivers already support this. >>> >>> We added an internal API to the gpiolib so that the lib, *internally* >>> can be made aware that a certain GPIO line is used for IRQs, >>> see commit d468bf9ecaabd3bf3a6134e5a369ced82b1d1ca1 >>> "gpio: add API to be strict about GPIO IRQ usage" >>> >>> So I guess the answer to the question is something like, fix >>> the GPIO driver to stop requiring the GPIO lines to be requested >>> and configured before being used as IRQs, delete that code, >>> and while you're at it add a call to gpiod_lock_as_irq() >>> to your GPIO driver in the right spot: examples are on the >>> mailing list and my mark-irqs branch in the GPIO tree. >> >> As far as I understand it this already works more or less with the driver. >> The problem is that the IRQ numbers are dynamically allocated, while the >> GPIO numbers apparently are not. So the board code knows the the GPIO number >> at compile time and can pass this to the diver which then does a gpio_to_irq >> to lookup the IRQ number. This of course isn't really a problem with >> devicetree, but only with platform board code. > > This has been solved *also* for platform board code by the new, fresh > GPIO descriptor mechanism, see Documentation/gpio/* > in Torvalds' git HEAD. This works when the GPIO numbers are dynamically allocated (which are static in this case), but not for IRQ numbers. - Lars -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
