From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:47103 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753639AbbHGPZi (ORCPT ); Fri, 7 Aug 2015 11:25:38 -0400 Message-ID: <55C4CDEB.9020505@roeck-us.net> Date: Fri, 07 Aug 2015 08:25:31 -0700 From: Guenter Roeck MIME-Version: 1.0 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 Subject: Re: [PATCH v6 1/2] drivers: watchdog: add a driver to support SAMA5D4 watchdog timer References: <1438856146-2459-1-git-send-email-wenyou.yang@atmel.com> <1438856206-2503-1-git-send-email-wenyou.yang@atmel.com> In-Reply-To: <1438856206-2503-1-git-send-email-wenyou.yang@atmel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org On 08/06/2015 03:16 AM, 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 Reviewed-by: Guenter Roeck