Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756109Ab1DSWAb (ORCPT ); Tue, 19 Apr 2011 18:00:31 -0400 Received: from www.hansjkoch.de ([178.63.77.200]:55650 "EHLO www.hansjkoch.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756078Ab1DSWA3 (ORCPT ); Tue, 19 Apr 2011 18:00:29 -0400 Date: Wed, 20 Apr 2011 00:00:18 +0200 From: "Hans J. Koch" To: Grant Likely Cc: Michal Simek , devicetree-discuss@lists.ozlabs.org, john.williams@petalogix.com, linux-kernel@vger.kernel.org, hjk@hansjkoch.de, w.sang@pengutronix.de, arnd@arndb.de Subject: Re: [PATCH v3] uio/pdrv_genirq: Add OF support Message-ID: <20110419220018.GB2772@local> References: <1303116654-5042-1-git-send-email-monstr@monstr.eu> <20110419060816.GA5252@ponder.secretlab.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110419060816.GA5252@ponder.secretlab.ca> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3056 Lines: 91 On Tue, Apr 19, 2011 at 12:08:16AM -0600, Grant Likely wrote: > On Mon, Apr 18, 2011 at 10:50:54AM +0200, Michal Simek wrote: > > Adding OF binding to genirq. > > Version string is setup to the "devicetree". > > > > Compatible string is not setup for now but you can add your > > custom compatible string to uio_of_genirq_match structure. > > > > For example with "uio" compatible string: > > static const struct of_device_id __devinitconst uio_of_genirq_match[] = { > > { .compatible = "uio", }, > > { /* empty for now */ }, > > }; > > > > Signed-off-by: Michal Simek > > > > --- > > > > v3: Fix irq binding > > Use "devicetree" as version string > > > > v2: Remove additional resource binding > > Setup correct version string > > Clear compatible string > > --- > > drivers/uio/uio_pdrv_genirq.c | 42 +++++++++++++++++++++++++++++++++++++++++ > > 1 files changed, 42 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c > > index 7174d51..c8d565a 100644 > > --- a/drivers/uio/uio_pdrv_genirq.c > > +++ b/drivers/uio/uio_pdrv_genirq.c > > @@ -23,6 +23,10 @@ > > #include > > #include > > > > +#include > > +#include > > +#include > > + > > #define DRIVER_NAME "uio_pdrv_genirq" > > > > struct uio_pdrv_genirq_platdata { > > @@ -97,6 +101,30 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev) > > int ret = -EINVAL; > > int i; > > > > + if (!uioinfo) { > > + int irq; > > + > > + /* alloc uioinfo for one device */ > > + uioinfo = kzalloc(sizeof(*uioinfo), GFP_KERNEL); > > + if (!uioinfo) { > > + ret = -ENOMEM; > > + dev_err(&pdev->dev, "unable to kmalloc\n"); > > + goto bad2; > > + } > > + uioinfo->name = pdev->dev.of_node->name; > > + uioinfo->version = "devicetree"; > > + > > + /* Multiple IRQs are not supported */ > > + irq = platform_get_irq(pdev, 0); > > + if (irq < 0) { > > PowerPC and x86 will return 0 for an unassigned IRQ, as will most platforms. That might be right for these architectures. On ARM SoCs, IRQ0 is often a normal irq like any other (e.g. "Audio DMA Controller 1" on Telechips TCC8000). We've had this discussion before. In my original uio_driver.h, UIO_IRQ_NONE was #defined as -1. There was heavy opposition against that, and I finally accepted a patch changing UIO_IRQ_NONE to 0. It's a tradeoff between 0 being a valid interrupt number on most archs and the convenience of the compiler automatically inserting a 0 into an unassigned variable. The above line if (irq < 0) { is probably a copy-paste leftover of some older code. Today, irq < 0 should never be true in UIO, so the line is wrong. Thanks for pointing to it, Hans -- 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/