From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372AbeEVXYd (ORCPT ); Tue, 22 May 2018 19:24:33 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:44868 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753251AbeEVXYb (ORCPT ); Tue, 22 May 2018 19:24:31 -0400 X-Google-Smtp-Source: AB8JxZperppmLePYGq9etUJQ1iyLReotRAi2VpwfJVW/J7GPh/RRIEpARWhIIm9RFqqprrG3CFkv3A== Subject: Re: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate To: Guenter Roeck Cc: Wim Van Sebroeck , Rob Herring , Mark Rutland , Frank Rowand , Catalin Marinas , Will Deacon , 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 References: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> <1527014840-21236-4-git-send-email-ray.jui@broadcom.com> <20180522205457.GA16363@roeck-us.net> From: Ray Jui Message-ID: <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> Date: Tue, 22 May 2018 16:24:25 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180522205457.GA16363@roeck-us.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guenter, On 5/22/2018 1:54 PM, Guenter Roeck wrote: > On Tue, May 22, 2018 at 11:47:18AM -0700, Ray Jui wrote: >> 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; > > return !!(readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK)); > Note ENABLE_MASK contains two bits (INT_ENABLE and RESET_ENABLE); therefore, a simple !!(expression) would not work? That is, the masked result needs to be compared against the mask again to ensure both bits are set, right? Thanks, Ray From mboxrd@z Thu Jan 1 00:00:00 1970 From: ray.jui@broadcom.com (Ray Jui) Date: Tue, 22 May 2018 16:24:25 -0700 Subject: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate In-Reply-To: <20180522205457.GA16363@roeck-us.net> References: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> <1527014840-21236-4-git-send-email-ray.jui@broadcom.com> <20180522205457.GA16363@roeck-us.net> Message-ID: <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Guenter, On 5/22/2018 1:54 PM, Guenter Roeck wrote: > On Tue, May 22, 2018 at 11:47:18AM -0700, Ray Jui wrote: >> 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; > > return !!(readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK)); > Note ENABLE_MASK contains two bits (INT_ENABLE and RESET_ENABLE); therefore, a simple !!(expression) would not work? That is, the masked result needs to be compared against the mask again to ensure both bits are set, right? Thanks, Ray