Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755255Ab3GYJop (ORCPT ); Thu, 25 Jul 2013 05:44:45 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:58941 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752418Ab3GYJoj (ORCPT ); Thu, 25 Jul 2013 05:44:39 -0400 From: Laurent Pinchart To: Linus Walleij Cc: "linux-kernel@vger.kernel.org" , Benjamin Herrenschmidt , Grant Likely , "linux-gpio@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Guennadi Liakhovetski Subject: Re: How to create IRQ mappings in a GPIO driver that doesn't control its IRQ domain ? Date: Thu, 25 Jul 2013 11:45:33 +0200 Message-ID: <1408178.cxAUTUGJc5@avalon> User-Agent: KMail/4.10.5 (Linux/3.8.13-gentoo; KDE/4.10.5; x86_64; ; ) In-Reply-To: References: <1624911.6TtmtVmU1T@avalon> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2037 Lines: 48 Hi Linus, Thank you for your answer. On Thursday 25 July 2013 11:20:54 Linus Walleij wrote: > On Wed, Jul 24, 2013 at 1:21 AM, Laurent Pinchart wrote: > > Has anyone run into a similar issue ? My gut feeling is that the > > architecture isn't right somewhere, but I can't really pinpoint where. > > We had a similar situation with the MFDs, where Mark, Lee and Sam came up > with the solution to include an irqdomain in the MFD cell spawn function: > > extern int mfd_add_devices(struct device *parent, int id, > struct mfd_cell *cells, int n_devs, > struct resource *mem_base, > int irq_base, struct irq_domain *irq_domain); > > When each cell (i.e. a platform device) is created, the irq for that cell > will be translated with irq_create_mapping() so the cell/platform device > just get a Linux IRQ it can use and do not need to worry about translating > it. > > Prior to this we had all sorts of exported translator functions for the IRQs > exported from each hub driver ---what a mess. > > Can you think about a parent/child relationship making it possible to pass > the irqs readily translated in this case? The two devices are independent, so there's no real parent/child relationship. However, as Grant proposed, I could list all the interrupts associated with GPIOs in the GPIO controller DT node. I would then just call irq_of_parse_and_map() in the .to_irq() handler to magically translate the GPIO number to a mapped IRQ number. The number of interrupts can be pretty high (up to 58 in the worst case so far), so an alternative would be to specify the interrupt-parent only, and call irq_create_of_mapping() directly. What solution would you prefer ? -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/