From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: Regarding hw irq to Linux irq mapping on ARM Date: Wed, 22 Sep 2010 08:52:18 -0300 Message-ID: <6ff62ca4-128a-436f-b85a-987849804a6e@email.android.com> References: <1285106546.30449.158.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Shaju Abraham , Benjamin Herrenschmidt Cc: devicetree-discuss , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Thomas Gleixner , Eric Miao , Jeremy Kerr List-Id: devicetree@vger.kernel.org "Shaju Abraham" wrote: >On Wed, Sep 22, 2010 at 3:32 AM, Benjamin Herrenschmidt > wrote: >> The main grief one could have with my scheme is the naming of irq_host >> which has confused people in the past. It should probably be irq_domain >> to make clear what it is. It generally have a 1:1 relationship to the >> irq_chip but there are cases where that isn't the case (essentially >> where you have multiple irq_chip per domain) for various reasons so it's >> better to keep those separate. >> > >How do we handle multiplexed interrupts ? For example a single interrupt line >representing multple irq sources. >We have ARM systems with single interrupt line on a VIC muxed to >192 different GPIO sources (each capable of generating interrupts). For such a >system the virq to hw irq mapping can get complex. Assign a separate irq number to each gpio. In effect, this makes the gpio controller an irq controller. g. -- Sent from my Android phone with K-9 Mail. Please excuse my brevity.