From patchwork Tue Sep 23 23:04:38 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Cartwright X-Patchwork-Id: 4960681 Return-Path: X-Original-To: patchwork-linux-arm-msm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0F454BEEA5 for ; Tue, 23 Sep 2014 23:11:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 407F720266 for ; Tue, 23 Sep 2014 23:11:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C7D52010E for ; Tue, 23 Sep 2014 23:11:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756693AbaIWXLL (ORCPT ); Tue, 23 Sep 2014 19:11:11 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:40541 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757187AbaIWXKM (ORCPT ); Tue, 23 Sep 2014 19:10:12 -0400 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 80884140825; Tue, 23 Sep 2014 23:10:12 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 7415A140828; Tue, 23 Sep 2014 23:10:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from joshc.qualcomm.com (rrcs-67-52-129-61.west.biz.rr.com [67.52.129.61]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: joshc@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 2441B140825; Tue, 23 Sep 2014 23:10:12 +0000 (UTC) Received: by joshc.qualcomm.com (Postfix, from userid 1000) id 56D385FD96; Tue, 23 Sep 2014 18:04:40 -0500 (CDT) From: Josh Cartwright To: Wim Van Sebroeck , linux-watchdog@vger.kernel.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Kumar Gala , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/3] watchdog: qcom: register a restart notifier Date: Tue, 23 Sep 2014 18:04:38 -0500 Message-Id: <2d539bc944f3e8fc70f39728b0f61fd171b2e5bf.1411513109.git.joshc@codeaurora.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The WDT's BITE_TIME warm-reset behavior can be leveraged as a last resort mechanism for triggering chip reset. Usually, other restart methods (such as PS_HOLD) are preferrable for issuing a more complete reset of the chip. As such, keep the priority of the watchdog notifier low. Signed-off-by: Josh Cartwright --- drivers/watchdog/qcom-wdt.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c index d5e46e2..eba92ef 100644 --- a/drivers/watchdog/qcom-wdt.c +++ b/drivers/watchdog/qcom-wdt.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #define WDT_RST 0x0 @@ -25,6 +26,7 @@ struct qcom_wdt { struct watchdog_device wdd; struct clk *clk; + struct notifier_block restart_nb; void __iomem *base; }; @@ -86,6 +88,23 @@ static const struct watchdog_info qcom_wdt_info = { .identity = KBUILD_MODNAME, }; +static int qcom_wdt_restart(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct qcom_wdt *wdt = container_of(nb, struct qcom_wdt, restart_nb); + + /* + * Trigger watchdog bite: + * Setup BITE_TIME to be very low, and enable WDT. + * 0x31F3 => 390ms @ 32kHz, also value at reset + */ + writel(0, wdt->base + WDT_EN); + writel(1, wdt->base + WDT_RST); + writel(0x31F3, wdt->base + WDT_BITE_TIME); + writel(1, wdt->base + WDT_EN); + return NOTIFY_DONE; +} + static int qcom_wdt_probe(struct platform_device *pdev) { struct qcom_wdt *wdt; @@ -141,6 +160,14 @@ static int qcom_wdt_probe(struct platform_device *pdev) return ret; } + /* + * WDT restart notifier has priority 0 (use as a last resort) + */ + wdt->restart_nb.notifier_call = qcom_wdt_restart; + ret = register_restart_handler(&wdt->restart_nb); + if (ret) + dev_err(&pdev->dev, "failed to setup restart handler\n"); + platform_set_drvdata(pdev, wdt); return 0; } @@ -149,6 +176,7 @@ static int qcom_wdt_remove(struct platform_device *pdev) { struct qcom_wdt *wdt = platform_get_drvdata(pdev); + unregister_restart_handler(&wdt->restart_nb); watchdog_unregister_device(&wdt->wdd); clk_disable_unprepare(wdt->clk); return 0;