Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751737AbbGMM6Y (ORCPT ); Mon, 13 Jul 2015 08:58:24 -0400 Received: from mail-oi0-f43.google.com ([209.85.218.43]:36101 "EHLO mail-oi0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751117AbbGMM6W (ORCPT ); Mon, 13 Jul 2015 08:58:22 -0400 MIME-Version: 1.0 In-Reply-To: <1434589243-502-4-git-send-email-gregory.0xf0@gmail.com> References: <1434589243-502-1-git-send-email-gregory.0xf0@gmail.com> <1434589243-502-4-git-send-email-gregory.0xf0@gmail.com> Date: Mon, 13 Jul 2015 14:58:22 +0200 Message-ID: Subject: Re: [PATCH v3 3/4] gpio: brcmstb: Add interrupt and wakeup source support From: Linus Walleij To: Gregory Fong Cc: "linux-gpio@vger.kernel.org" , Alexandre Courbot , bcm-kernel-feedback-list , Brian Norris , "devicetree@vger.kernel.org" , Florian Fainelli , Ian Campbell , Kumar Gala , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Mark Rutland , Pawel Moll , Rob Herring , Russell King Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3024 Lines: 76 On Thu, Jun 18, 2015 at 3:00 AM, Gregory Fong wrote: > Uses the gpiolib irqchip helpers. For this to work, the irq setup > function is called once per bank instead of once per device. Note > that all known uses of this block have a BCM7120 L2 interrupt > controller as a parent. Supports interrupts for all GPIOs. > > In the IRQ handler, we check for raised IRQs for invalid GPIOs and > warn (ratelimited) if they're encountered. > > Also, several drivers (e.g. gpio-keys) allow for GPIOs to be > configured as wakeup sources, and this GPIO controller supports that > through a separate interrupt path. > > The de-facto standard DT property "wakeup-source" is checked, since > that indicates whether the GPIO controller hardware can wake. Uses > the IRQCHIP_MASK_ON_SUSPEND irq_chip flag because UPG GIO doesn't have > any of its own wakeup source configuration. > > Aside regarding gpiolib irqchip helpers: It wasn't obvious (to me) > that you can have multiple chained irqchips and associated IRQ domains > for a single parent IRQ, and as long as the xlate function is written > correctly, a GPIO IRQ request end up checking the correct domain and > will get associated with the correct IRQ. What helps make this clear > is to read > drivers/gpio/gpiolib-of.c: > - of_gpiochip_find_and_xlate() > - of_get_named_gpiod_flags() > drivers/gpio/gpiolib.c: > - gpiochip_find() Sorry for the unclarities, this is a bit hairy. Suggestions as to how we can make it easier and/or bring code for this into gpiolib are welcome. Right now I have a hard time seeing any way to make this more generic and helpful :/ Overall this patch looks real nice. Some nitpicks below. > @@ -164,6 +398,16 @@ static int brcmstb_gpio_probe(struct platform_device *pdev) > priv->reg_base = reg_base; > priv->pdev = pdev; > > + if (of_property_read_bool(np, "interrupt-controller")) { > + priv->parent_irq = platform_get_irq(pdev, 0); > + if (priv->parent_irq < 0) { This should be <= 0 since 0 is NO_IRQ > + dev_err(dev, "Couldn't get IRQ"); > + return -ENOENT; > + } > + } else { > + priv->parent_irq = -ENOENT; > + } Why should this code only execute if the node is marked "interrupt-controller"? It makes it seem like IRQs cannot arrive to it unless it is intended to serve other consumers. Maybe in practice this is true, but... > + if (priv->parent_irq >= 0) { > + err = brcmstb_gpio_irq_setup(pdev, bank); > + if (err) > + goto fail; > + } Again 0 is NO_IRQ so this should be > 0 not >= 0. Yours, Linus Walleij -- 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/