From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v4 1/2] drivers: watchdog: add a driver to support SAMA5D4 watchdog timer Date: Thu, 06 Aug 2015 01:05:27 -0700 Message-ID: <55C31547.2040207@roeck-us.net> References: <1438837170-4518-1-git-send-email-wenyou.yang@atmel.com> <1438837170-4518-2-git-send-email-wenyou.yang@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1438837170-4518-2-git-send-email-wenyou.yang@atmel.com> Sender: linux-kernel-owner@vger.kernel.org To: Wenyou Yang , wim@iguana.be, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org Cc: sylvain.rochet@finsecur.com, nicolas.ferre@atmel.com, boris.brezillon@free-electrons.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On 08/05/2015 09:59 PM, Wenyou Yang wrote: >>>From SAMA5D4, the watchdog timer is upgrated with a new feature, > which is describled as in the datasheet, "WDT_MR can be written > until a LOCKMR command is issued in WDT_CR". > That is to say, as long as the bootstrap and u-boot don't issue > a LOCKMR command, WDT_MR can be written more than once in the driver. > > So the SAMA5D4 watchdog driver's implementation is different from > the at91sam9260 watchdog driver implemented in file at91sam9_wdt.c. > The user application open the device file to enable the watchdog timer > hardware, and close to disable it, and set the watchdog timer timeout > by seting WDV and WDD fields of WDT_MR register, and ping the watchdog > by issuing WDRSTT command to WDT_CR register with hard-coded key. > > Signed-off-by: Wenyou Yang > --- [ ... ] > + > +/* minimum and maximum watchdog timeout, in seconds */ > +#define MIN_WDT_TIMEOUT 1 > +#define MAX_WDT_TIMEOUT 16 > +#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT > + > +#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0) > + Why did you replace the spaces after #define with tabs ? I understand this is done in the at91.h file, but that is bad enough, it doesn't add any value, and I don't see a reason to do it here. > + > + if ((wdt->config & AT91_WDT_WDFIEN) && irq) { > + ret = devm_request_irq(&pdev->dev, irq, sama5d4_wdt_irq_handler, > + 0, pdev->name, pdev); I just realized - this interrupt is registered with flags set to 0, while in the at91sam driver the flags are "IRQF_SHARED | IRQF_IRQPOLL | IRQF_NO_SUSPEND". Is this different with the new SOC ? Thanks, Guenter