From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754120AbcC3U77 (ORCPT ); Wed, 30 Mar 2016 16:59:59 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:42995 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753066AbcC3U75 (ORCPT ); Wed, 30 Mar 2016 16:59:57 -0400 Date: Wed, 30 Mar 2016 13:59:58 -0700 From: Guenter Roeck To: Maxime Jayat Cc: Joseph McNally , Jean Delvare , lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org Subject: Re: ncpXXxh103 compensation values? Message-ID: <20160330205958.GA21993@roeck-us.net> References: <56FBDCBD.7080802@gmail.com> <56FBF7B1.1030407@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <56FBF7B1.1030407@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Authenticated_sender: guenter@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: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@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 Hi Maxime, On Wed, Mar 30, 2016 at 05:58:41PM +0200, Maxime Jayat wrote: > I don't think it is wrong to use ncpXXxh103 instead of ncp15xh103, > because the first number refers to the physical size of the thermistor > and should not change its behavior. In fact the datasheet does the same > kind of grouping. > > I was just wondering what was the reason for the discrepancy between the > datasheet and your values. > Indeed the datasheet I linked earlier, at page 15, gives you verbatim > the content of this array and the result of your calculation does not > match it. > It is not _absurdly_ wrong but, at first sight, it seems like there is a > 10 degrees difference at the extremes (but 10 kOhm at 25 C is correct). > Can the two of you sort this out and send me a fixup patch if necessary ? Thanks, Guenter p.s.: Please don't top-post. > Le 30/03/2016 17:09, Joseph McNally a écrit : > > Hello Maxime, > > > > This data was calculated for a Murata NCP15XH103XXXXX. > > > > You have illustrated something to me with your question though. When I > > uploaded this patch, I was following the format of the compensation > > tables that are already present in the file. So i used "ncpXXxh103" > > instead of "ncp15xh103". Also, it was my first patch submitted to the > > Linux kernel. So I may have been over thinking some things! With some > > hindsight, I see that the name is misleading. I'm going to have to > > revisit this patch to make it more 'generic' for other thermistors, or > > make it more specific for this particular thermistor. > > > > I hope that answers your questions. Thanks for pointing this out to me. > > > > Regards, > > Joseph > > > > On Wed, Mar 30, 2016 at 3:03 PM, Maxime Jayat > > wrote: > > > > Hello Joseph, > > > > You recently added support for the ncpXXxh103 in > > drivers/hwmon/ntc_thermistor.c with the following array of values: > > > > +static const struct ntc_compensation ncpXXxh103[] = { > > + { .temp_c = -40, .ohm = 247565 }, > > + { .temp_c = -35, .ohm = 181742 }, > > + { .temp_c = -30, .ohm = 135128 }, > > + { .temp_c = -25, .ohm = 101678 }, > > + { .temp_c = -20, .ohm = 77373 }, > > + { .temp_c = -15, .ohm = 59504 }, > > + { .temp_c = -10, .ohm = 46222 }, > > + { .temp_c = -5, .ohm = 36244 }, > > + { .temp_c = 0, .ohm = 28674 }, > > + { .temp_c = 5, .ohm = 22878 }, > > + { .temp_c = 10, .ohm = 18399 }, > > + { .temp_c = 15, .ohm = 14910 }, > > + { .temp_c = 20, .ohm = 12169 }, > > + { .temp_c = 25, .ohm = 10000 }, > > + { .temp_c = 30, .ohm = 8271 }, > > + { .temp_c = 35, .ohm = 6883 }, > > + { .temp_c = 40, .ohm = 5762 }, > > + { .temp_c = 45, .ohm = 4851 }, > > + { .temp_c = 50, .ohm = 4105 }, > > + { .temp_c = 55, .ohm = 3492 }, > > + { .temp_c = 60, .ohm = 2985 }, > > + { .temp_c = 65, .ohm = 2563 }, > > + { .temp_c = 70, .ohm = 2211 }, > > + { .temp_c = 75, .ohm = 1915 }, > > + { .temp_c = 80, .ohm = 1666 }, > > + { .temp_c = 85, .ohm = 1454 }, > > + { .temp_c = 90, .ohm = 1275 }, > > + { .temp_c = 95, .ohm = 1121 }, > > + { .temp_c = 100, .ohm = 990 }, > > + { .temp_c = 105, .ohm = 876 }, > > + { .temp_c = 110, .ohm = 779 }, > > + { .temp_c = 115, .ohm = 694 }, > > + { .temp_c = 120, .ohm = 620 }, > > + { .temp_c = 125, .ohm = 556 }, > > +}; > > + > > > > Where are these taken from? > > Unlike the other thermistors in the file, these values don't seem to > > match anything in the Murata NTC Thermistor Datasheet. > > See: > > http://www.murata.com/~/media/webrenewal/support/library/catalog/products/thermistor/ntc/r44e.ashx > > > > -- > > Maxime Jayat > > > > > -- > Maxime Jayat