From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936204AbcA1Bv4 (ORCPT ); Wed, 27 Jan 2016 20:51:56 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:42896 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932213AbcA1Bvy (ORCPT ); Wed, 27 Jan 2016 20:51:54 -0500 Subject: Re: [PATCH v3] watchdog: Add watchdog timer support for the WinSystems EBC-C384 To: William Breathitt Gray , wim@iguana.be References: <20160125190942.GA6824@sophia> <20160125192810.2487661b@lxorguk.ukuu.org.uk> <56A6889E.60208@roeck-us.net> <56A6B198.2080205@gmail.com> <56A6CB48.4010402@roeck-us.net> <56A80391.40009@gmail.com> <56A84F75.3050805@roeck-us.net> <20160128001836.GA15216@sophia> Cc: One Thousand Gnomes , linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org From: Guenter Roeck Message-ID: <56A97436.1090703@roeck-us.net> Date: Wed, 27 Jan 2016 17:51:50 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160128001836.GA15216@sophia> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/27/2016 04:18 PM, William Breathitt Gray wrote: > On Tue, Jan 26, 2016 at 09:02:45PM -0800, Guenter Roeck wrote: >>> Unfortunately, the sensors-detect only reported "No" for each Super I/O >>> chip test, while the superiotool gave an unhelpful "No Super I/O chip >>> detected" message. >>> >> >> Too bad. That suggests that the watchdog may in fact be implemented in the fpga. > > I received a response from WinSystems: the watchdog timer is implemented > in the Lattice FPGA (base address 0x298), along with other WinSystems > firmware. I was offered two methods of identifying the chip. > > The first method is to use a 16-bit read of the register at port address > 0x29E to get the version number of the watchdog timer; my machine > reported a value of 0x0009. Unfortunately, I don't believe this method > is very reliable since the version number may not be consistent across > these motherboards, and the same value could easily happen to be > returned by an unknown hardware. > > The second method is slightly more involved so I'll quote WinSystems: > >> 8-bit read of 299h – save this value >> 8-bit write of 60h to 299h >> 16-bit read of 29ah should return the base address of the WDT which is 564h >> 8-bit write of saved value to 299h - don’t want t accidentally change the WDT base address > > If the system does return a value of 0x564, then it's pretty safe to say > that the watchdog timer is implemented on the chip. However, I'm not > sure it would be safe to send write commands to a port address until the > hardware has been identified; this second method may not be the best > route either. > > What do you think? > Let's stick with DMI. Thanks, Guenter