From owner-freebsd-hackers@freebsd.org Fri May 19 20:20:04 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D24E6D747D4 for ; Fri, 19 May 2017 20:20:04 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citapm.icyb.net.ua (citapm.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 2805B1FAC for ; Fri, 19 May 2017 20:20:03 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citapm.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id XAA15781; Fri, 19 May 2017 23:19:55 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1dBoNP-0009Py-Ls; Fri, 19 May 2017 23:19:55 +0300 Subject: Re: iMC SMBus controller driver To: Ravi Pokala , "freebsd-hackers@freebsd.org" References: <532facb6-00bb-52d2-3e99-4e8c1bc16670@FreeBSD.org> <2428158C-45B3-434A-A2FD-B24A655C7564@panasas.com> From: Andriy Gapon Message-ID: Date: Fri, 19 May 2017 23:18:59 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <2428158C-45B3-434A-A2FD-B24A655C7564@panasas.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 May 2017 20:20:04 -0000 On 19/05/2017 18:00, Ravi Pokala wrote: > Yes and no. ismt(4) is a non-ichsmb SMBus controller, but the driver only supports Atom S1200 (Briarwood) and Atom C2000 (Avoton / Rangeley) SoCs. But maybe it just needs to have newer devices added to the list...? > > As it happens, I have the datasheet for the Rangeley at my fingertips. I searched for some of the magic numbers from ismt(4), and found where the "SMT" SMBus controller (PCI 0:13:0) is documented. I also did some digging on Intel's site, and found Volume 2 of the Broadwell Xeon datasheet, where the iMC (PCI 0:19:0 and 0:22:0) is documented. Unfortunately, Rangeley's SMT SMBus controller and Broadwell's iMC's SMBus controller bear no resemblance to each other. > > So, no, ismt(4) is not the droid ^W driver I'm looking for. :-/ Oh, I see now. It's quite a specialized controller for talking to things on DIMMs. The interface is quite different from any other controller, but it is very simple, because of the limited functionality it provides. So, it shouldn't be hard to write a driver for it. I found this submission for a Linux driver, but not sure if it was committed: http://lm-sensors.lm-sensors.narkive.com/Xy87Q8tj/patch-v3-0-4-imc-smbus-tsod-hwmon-devices-and-eeprom-modalias -- Andriy Gapon