From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27355C433E1 for ; Tue, 30 Jun 2020 17:59:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D13E20724 for ; Tue, 30 Jun 2020 17:59:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T2FDMCan" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390540AbgF3R7M (ORCPT ); Tue, 30 Jun 2020 13:59:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390531AbgF3R7L (ORCPT ); Tue, 30 Jun 2020 13:59:11 -0400 Received: from mail-pl1-x644.google.com (mail-pl1-x644.google.com [IPv6:2607:f8b0:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EFDADC061755; Tue, 30 Jun 2020 10:59:10 -0700 (PDT) Received: by mail-pl1-x644.google.com with SMTP id bj10so3540010plb.11; Tue, 30 Jun 2020 10:59:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=FF1CCKbtJtqt6Q/pYRKenLml0HvaHdcmKl2JhZVArNM=; b=T2FDMCanxrLjiStIVNFqHMes676MPRpLG5S6N5caQna9whxiW/FqrzPgIl6R481yy3 f6fciCq2zxl1JC/JhDp0qygodCtFnzTzWBnJ7HEBgiHN0sSeYEyRsx53buUc2OyX2gOC P+6O4SuMULSXQtHyJKmM/uC336E+aE8tzkMlcP4AADVF4vQODda6Tet9hVnadbMbCFqW wzpHG6GLbHpwXojLfrf2pnKepTil4NTG590nuMFhUZ0OB+ZcikJkqxaNYakXZqZNYvYZ 4KtXNumpZHRu03pR6zV1jUSDv2w+tExTRLQ3WFCcCcfb41MjLt5JXE3aj620Kf3DLuvD q6LA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=FF1CCKbtJtqt6Q/pYRKenLml0HvaHdcmKl2JhZVArNM=; b=IM8W0eTfvbUx5wZexugCFAPOUfQg7PVdkuojgTKdR2X48Ol0g56G4yYGI+dih9KS/g BdEUQ7GFtrcQ38G+mzcDSpujoR54MAZ554z+7czQUg3LfU33UOykKof5CklEnzqnNKB/ XeD8GBqNzMBd8YpAxVYAUvNzz/6B8m6o/jDdvrENgqJcUNggpVJVOYU7B+r7OC1gTe/K H3LyNuJ9rc2NBBn5ZbmKb51wiqvfWHEakFcZQTjqzu2n4SSewmt1L9xbWBmK4C69lGu3 FBhlXM5rtCsdHTUK596VrKTVJ0N6/0iE+xSXaFRT7Fh9IJ7XQc8q7lkJxk96V2JArmwN RMkQ== X-Gm-Message-State: AOAM5329UXai3h/xyI+rf2qvR/FvbXHS93FMj3NkJf6F+mYBM6zyEP/Z 8OAxNadbXQAquP1TSKs7CJOn+3ww X-Google-Smtp-Source: ABdhPJx9G5bEpO+CfPHgGFPB2meXHaGqAf+bkXDYsH/t9yhybRklN/TL2ddXax2r2Mpafaqja+/drg== X-Received: by 2002:a17:90a:c087:: with SMTP id o7mr20465792pjs.37.1593539950495; Tue, 30 Jun 2020 10:59:10 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id t29sm3357251pfq.50.2020.06.30.10.59.09 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 30 Jun 2020 10:59:10 -0700 (PDT) Date: Tue, 30 Jun 2020 10:59:08 -0700 From: Guenter Roeck To: Chu Lin Cc: jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, jasonling@google.com, belgaied@google.com, zhongqil@google.com Subject: Re: [PATCH] hwmon:max6697: Allow max6581 to set temperature read offset Message-ID: <20200630175908.GG629@roeck-us.net> References: <20200630174350.2842555-1-linchuyuan@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200630174350.2842555-1-linchuyuan@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 30, 2020 at 05:43:50PM +0000, Chu Lin wrote: > Per max6581, reg 4d and reg 4e is used for temperature read offset. > This patch will let the user specify the temperature read offset for > max6581. This patch is tested on max6581 and only applies to max6581. > > Testing: > dts: temperature-read-offset = <0xde 0x0>; This should not be implemented this way. Instead, the standard tempX_offset attribute should be used, with appropriate code to determine affected channels (since there is only one offset value, and since it can be enabled per channel). A secondary question is if and how to set the temperature offset via devicetree; that will have to be documented and approved by a DT maintainer. I would think, though, that the offset should be specified in milli-degrees C and not as raw chip data. Thanks, Guenter > > verify: iotools smbus_read8 0x4d 0x4e > 0x6F > > Signed-off-by: Chu Lin > --- > drivers/hwmon/max6697.c | 19 +++++++++++++++++-- > include/linux/platform_data/max6697.h | 4 ++++ > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/max6697.c b/drivers/hwmon/max6697.c > index 743752a2467a..16c0f0995a12 100644 > --- a/drivers/hwmon/max6697.c > +++ b/drivers/hwmon/max6697.c > @@ -493,8 +493,13 @@ static void max6697_get_config_of(struct device_node *node, > } > prop = of_get_property(node, "transistor-ideality", &len); > if (prop && len == 2 * sizeof(u32)) { > - pdata->ideality_mask = be32_to_cpu(prop[0]); > - pdata->ideality_value = be32_to_cpu(prop[1]); > + pdata->ideality_mask = be32_to_cpu(prop[0]); > + pdata->ideality_value = be32_to_cpu(prop[1]); > + } > + prop = of_get_property(node, "temperature-read-offset", &len); > + if (prop && len == 2 * sizeof(u32)) { > + pdata->offset_mask = be32_to_cpu(prop[0]); > + pdata->offset_value = be32_to_cpu(prop[1]); > } > } > > @@ -586,6 +591,16 @@ static int max6697_init_chip(struct max6697_data *data, > pdata->ideality_mask >> 1); > if (ret < 0) > return ret; > + ret = i2c_smbus_write_byte_data(client, > + MAX6581_REG_OFFSET, > + pdata->offset_value); > + if (ret < 0) > + return ret; > + ret = i2c_smbus_write_byte_data(client, > + MAX6581_REG_OFFSET_SELECT, > + pdata->offset_mask >> 1); > + if (ret < 0) > + return ret; > } > done: > data->update_interval = factor * MAX6697_CONV_TIME; > diff --git a/include/linux/platform_data/max6697.h b/include/linux/platform_data/max6697.h > index 6fbb70005541..ff98adfe9d8d 100644 > --- a/include/linux/platform_data/max6697.h > +++ b/include/linux/platform_data/max6697.h > @@ -28,6 +28,10 @@ struct max6697_platform_data { > u8 ideality_value; /* transistor ideality as per > * MAX6581 datasheet > */ > + u8 offset_mask; /* set bit to 0 to disable */ > + u8 offset_value; /* temperature read offset as > + * MAX6581 datasheet > + */ > }; > > #endif /* MAX6697_H */ > -- > 2.27.0.212.ge8ba1cc988-goog >