From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752080AbeEVSrs (ORCPT ); Tue, 22 May 2018 14:47:48 -0400 Received: from mail-qt0-f193.google.com ([209.85.216.193]:41433 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758AbeEVSro (ORCPT ); Tue, 22 May 2018 14:47:44 -0400 X-Google-Smtp-Source: AB8JxZpvNL9w+WbQlmfp5gV6IIq7ifhFNw9IeZ79P0KTvpr7b2qm9jZ+kIb6fqhOCEcKQd/BZoJAwg== From: Ray Jui To: Wim Van Sebroeck , Guenter Roeck , Rob Herring , Mark Rutland , Frank Rowand , Catalin Marinas , Will Deacon Cc: linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, Ray Jui Subject: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate Date: Tue, 22 May 2018 11:47:18 -0700 Message-Id: <1527014840-21236-4-git-send-email-ray.jui@broadcom.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> References: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the watchdog hardware is already enabled during the boot process, when the Linux watchdog driver loads, it should reset the watchdog and tell the watchdog framework. As a result, ping can be generated from the watchdog framework, until the userspace watchdog daemon takes over control Signed-off-by: Ray Jui Reviewed-by: Vladimir Olovyannikov Reviewed-by: Scott Branden --- drivers/watchdog/sp805_wdt.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c index 1484609..408ffbe 100644 --- a/drivers/watchdog/sp805_wdt.c +++ b/drivers/watchdog/sp805_wdt.c @@ -42,6 +42,7 @@ /* control register masks */ #define INT_ENABLE (1 << 0) #define RESET_ENABLE (1 << 1) + #define ENABLE_MASK (INT_ENABLE | RESET_ENABLE) #define WDTINTCLR 0x00C #define WDTRIS 0x010 #define WDTMIS 0x014 @@ -74,6 +75,18 @@ module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Set to 1 to keep watchdog running after device release"); +/* returns true if wdt is running; otherwise returns false */ +static bool wdt_is_running(struct watchdog_device *wdd) +{ + struct sp805_wdt *wdt = watchdog_get_drvdata(wdd); + + if ((readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK) == + ENABLE_MASK) + return true; + else + return false; +} + /* This routine finds load value that will reset system in required timout */ static int wdt_setload(struct watchdog_device *wdd, unsigned int timeout) { @@ -239,6 +252,15 @@ sp805_wdt_probe(struct amba_device *adev, const struct amba_id *id) watchdog_init_timeout(&wdt->wdd, 0, &adev->dev); wdt_setload(&wdt->wdd, wdt->wdd.timeout); + /* + * If HW is already running, enable/reset the wdt and set the running + * bit to tell the wdt subsystem + */ + if (wdt_is_running(&wdt->wdd)) { + wdt_enable(&wdt->wdd); + set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); + } + ret = watchdog_register_device(&wdt->wdd); if (ret) { dev_err(&adev->dev, "watchdog_register_device() failed: %d\n", -- 2.1.4