From patchwork Mon Mar 2 09:18:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris BREZILLON X-Patchwork-Id: 5910821 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 21A5E9F36A for ; Mon, 2 Mar 2015 09:18:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3954B2020F for ; Mon, 2 Mar 2015 09:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A7CC2021A for ; Mon, 2 Mar 2015 09:18:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753626AbbCBJSb (ORCPT ); Mon, 2 Mar 2015 04:18:31 -0500 Received: from down.free-electrons.com ([37.187.137.238]:51248 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750929AbbCBJSZ (ORCPT ); Mon, 2 Mar 2015 04:18:25 -0500 Received: by mail.free-electrons.com (Postfix, from userid 106) id 5C30B300; Mon, 2 Mar 2015 10:18:25 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from localhost.localdomain (col31-4-88-188-83-94.fbx.proxad.net [88.188.83.94]) by mail.free-electrons.com (Postfix) with ESMTPSA id 2E82A498; Mon, 2 Mar 2015 10:18:24 +0100 (CET) From: Boris Brezillon To: Thomas Gleixner , Jason Cooper , Peter Zijlstra , Mark Rutland , "Rafael J. Wysocki" Cc: Len Brown , Pavel Machek , linux-pm@vger.kernel.org, Wim Van Sebroeck , linux-watchdog@vger.kernel.org, Alessandro Zummo , rtc-linux@googlegroups.com, Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, Mike Turquette , linux-kernel@vger.kernel.org, Nicolas Ferre , Jean-Christophe Plagniol-Villard , Alexandre Belloni , linux-arm-kernel@lists.infradead.org, Boris Brezillon Subject: [PATCH v2 2/6] rtc: at91sam9: rework wakeup and interrupt handling Date: Mon, 2 Mar 2015 10:18:14 +0100 Message-Id: <1425287898-15093-3-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1425287898-15093-1-git-send-email-boris.brezillon@free-electrons.com> References: <1425287898-15093-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The IRQ line used by the RTC device is usually shared with the system timer (PIT) on at91 platforms. Since timers are registering their handlers with IRQF_NO_SUSPEND, we should expect being called in suspended state, and properly wake the system up when this is the case. Set IRQF_COND_SUSPEND flag when registering the IRQ handler to inform irq core that it can safely be called while the system is suspended. Signed-off-by: Boris Brezillon --- drivers/rtc/rtc-at91sam9.c | 73 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 12 deletions(-) diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c index 2183fd2..5ccaee3 100644 --- a/drivers/rtc/rtc-at91sam9.c +++ b/drivers/rtc/rtc-at91sam9.c @@ -23,6 +23,7 @@ #include #include #include +#include #include /* @@ -77,6 +78,9 @@ struct sam9_rtc { unsigned int gpbr_offset; int irq; struct clk *sclk; + bool suspended; + unsigned long events; + spinlock_t lock; }; #define rtt_readl(rtc, field) \ @@ -271,14 +275,9 @@ static int at91_rtc_proc(struct device *dev, struct seq_file *seq) return 0; } -/* - * IRQ handler for the RTC - */ -static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *rtc) { - struct sam9_rtc *rtc = _rtc; u32 sr, mr; - unsigned long events = 0; /* Shared interrupt may be for another device. Note: reading * SR clears it, so we must only read it in this irq handler! @@ -290,18 +289,54 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) /* alarm status */ if (sr & AT91_RTT_ALMS) - events |= (RTC_AF | RTC_IRQF); + rtc->events |= (RTC_AF | RTC_IRQF); /* timer update/increment */ if (sr & AT91_RTT_RTTINC) - events |= (RTC_UF | RTC_IRQF); + rtc->events |= (RTC_UF | RTC_IRQF); + + return IRQ_HANDLED; +} + +static void at91_rtc_flush_events(struct sam9_rtc *rtc) +{ + if (!rtc->events) + return; - rtc_update_irq(rtc->rtcdev, 1, events); + rtc_update_irq(rtc->rtcdev, 1, rtc->events); + rtc->events = 0; pr_debug("%s: num=%ld, events=0x%02lx\n", __func__, - events >> 8, events & 0x000000FF); + rtc->events >> 8, rtc->events & 0x000000FF); +} - return IRQ_HANDLED; +/* + * IRQ handler for the RTC + */ +static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +{ + struct sam9_rtc *rtc = _rtc; + int ret; + + spin_lock(&rtc->lock); + + ret = at91_rtc_cache_events(rtc); + + /* We're called in suspended state */ + if (rtc->suspended) { + /* Mask irqs coming from this peripheral */ + rtt_writel(rtc, MR, + rtt_readl(rtc, MR) & + ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)); + /* Trigger a system wakeup */ + pm_system_wakeup(); + } else { + at91_rtc_flush_events(rtc); + } + + spin_unlock(&rtc->lock); + + return ret; } static const struct rtc_class_ops at91_rtc_ops = { @@ -421,7 +456,8 @@ static int at91_rtc_probe(struct platform_device *pdev) /* register irq handler after we know what name we'll use */ ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt, - IRQF_SHARED, dev_name(&rtc->rtcdev->dev), rtc); + IRQF_SHARED | IRQF_COND_SUSPEND, + dev_name(&rtc->rtcdev->dev), rtc); if (ret) { dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq); return ret; @@ -482,7 +518,12 @@ static int at91_rtc_suspend(struct device *dev) rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN); if (rtc->imr) { if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) { + unsigned long flags; + enable_irq_wake(rtc->irq); + spin_lock_irqsave(&rtc->lock, flags); + rtc->suspended = true; + spin_unlock_irqrestore(&rtc->lock, flags); /* don't let RTTINC cause wakeups */ if (mr & AT91_RTT_RTTINCIEN) rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN); @@ -499,10 +540,18 @@ static int at91_rtc_resume(struct device *dev) u32 mr; if (rtc->imr) { + unsigned long flags; + if (device_may_wakeup(dev)) disable_irq_wake(rtc->irq); mr = rtt_readl(rtc, MR); rtt_writel(rtc, MR, mr | rtc->imr); + + spin_lock_irqsave(&rtc->lock, flags); + rtc->suspended = false; + at91_rtc_cache_events(rtc); + at91_rtc_flush_events(rtc); + spin_unlock_irqrestore(&rtc->lock, flags); } return 0;