From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: gpio irq on Beagleboard Date: Fri, 16 Apr 2010 08:13:17 +0300 Message-ID: <20100416051317.GB26263@nokia.com> References: <38B49E6266DD4380903FF7A5E6162A5D@rhonda.vtc.ru> <8A909C07C62544C9924984F81D5F4FBA@rhonda.vtc.ru> Reply-To: felipe.balbi@nokia.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Received: from smtp.nokia.com ([192.100.105.134]:56604 "EHLO mgw-mx09.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752098Ab0DPFNi (ORCPT ); Fri, 16 Apr 2010 01:13:38 -0400 Content-Disposition: inline In-Reply-To: <8A909C07C62544C9924984F81D5F4FBA@rhonda.vtc.ru> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: ext Andrew Tverdohlebov Cc: "linux-omap@vger.kernel.org" On Fri, Apr 16, 2010 at 06:59:19AM +0200, ext Andrew Tverdohlebov wrote: >Dear linux-omap community, > >I am writing a simple driver for BeagleBoard >and trying to get an understanding of how interrupts work. > >Could you please answer a small question. What is a difference between irq > and virtual_irq_start in structure gpio_bank in file > arch/arm/plat-omap/gpio.c > As far as I understood irq corresponds to real hardware interrupts while > virtual_irq_start is completely obscure for me. > I didn't find a clue in the documentation. it's where the gpio irqs could be placed (numbering-wise) after the irq controller. I mean, if the irq controller has 192 irqs, gpio irqs have to be numbered 193, 194, 195, etc... so virtual_irq_base is that initial number. hope I made myself clear enough :-p if you take a look at the gpio_bank arrays on that same file and look at the fourth initialization, you can get a clue. Take a look at the IH_GPIO_BASE define, for example. -- balbi