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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC22DC678D4 for ; Tue, 7 Mar 2023 17:29:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230290AbjCGR3F (ORCPT ); Tue, 7 Mar 2023 12:29:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231641AbjCGR2a (ORCPT ); Tue, 7 Mar 2023 12:28:30 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE08D96094 for ; Tue, 7 Mar 2023 09:23:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 901F9B819AB for ; Tue, 7 Mar 2023 17:23:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA70AC433D2; Tue, 7 Mar 2023 17:23:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678209821; bh=UKj/Yz1lvupNizeVrO4etaeCaHmugzEYepmlLeh6XJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xAV1H73EkatjNnD3JGU1dpDgDQayDOka45A0qUuwUuFdsiw/KQLC65PGOqHjDbw43 Epf8hZTutZ2kU5XC0jw83nXW6M/9UMVfY2dj/D613ifUTQblR0TUh70l8NYu2OWZi9 /4y2b2hw2/7OIpmf1yOUG6LXsBH2QqOPHAMPt9pI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Armin Wolf , Guenter Roeck , Sasha Levin Subject: [PATCH 6.2 0342/1001] hwmon: (ftsteutates) Fix scaling of measurements Date: Tue, 7 Mar 2023 17:51:54 +0100 Message-Id: <20230307170036.308265264@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Armin Wolf [ Upstream commit ca8fd8c16a8b77dfcf7f6ce52d2c863220693a78 ] A user complained that the ftsteutates driver was displaying bogus values since its introduction. This happens because the sensor measurements need to be scaled in order to produce meaningful results: - the fan speed needs to be multiplied by 60 since its in RPS - the temperature is in degrees celsius and needs an offset of 64 - the voltage is in 1/256 of 3.3V The offical datasheet says the voltage needs to be divided by 256, but this is likely an off-by-one-error, since even the BIOS devides by 255 (otherwise 3.3V could not be measured). The voltage channels additionally need a board-specific multiplier, however this can be done by the driver since its board-specific. The reason the missing scaling of measurements is the way Fujitsu used this driver when it was still out-of-tree. Back then, all scaling was done in userspace by libsensors, even the generic one. Tested on a Fujitsu DS3401-B1. Fixes: 08426eda58e0 ("hwmon: Add driver for FTS BMC chip "Teutates"") Signed-off-by: Armin Wolf Link: https://lore.kernel.org/r/20221224041855.83981-2-W_Armin@gmx.de Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- Documentation/hwmon/ftsteutates.rst | 4 ++++ drivers/hwmon/ftsteutates.c | 19 +++++++++++++------ 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/Documentation/hwmon/ftsteutates.rst b/Documentation/hwmon/ftsteutates.rst index 58a2483d8d0da..198fa8e2819da 100644 --- a/Documentation/hwmon/ftsteutates.rst +++ b/Documentation/hwmon/ftsteutates.rst @@ -22,6 +22,10 @@ enhancements. It can monitor up to 4 voltages, 16 temperatures and 8 fans. It also contains an integrated watchdog which is currently implemented in this driver. +The 4 voltages require a board-specific multiplier, since the BMC can +only measure voltages up to 3.3V and thus relies on voltage dividers. +Consult your motherboard manual for details. + To clear a temperature or fan alarm, execute the following command with the correct path to the alarm file:: diff --git a/drivers/hwmon/ftsteutates.c b/drivers/hwmon/ftsteutates.c index f5b8e724a8ca1..ffa0bb3648775 100644 --- a/drivers/hwmon/ftsteutates.c +++ b/drivers/hwmon/ftsteutates.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -347,13 +348,15 @@ static ssize_t in_value_show(struct device *dev, { struct fts_data *data = dev_get_drvdata(dev); int index = to_sensor_dev_attr(devattr)->index; - int err; + int value, err; err = fts_update_device(data); if (err < 0) return err; - return sprintf(buf, "%u\n", data->volt[index]); + value = DIV_ROUND_CLOSEST(data->volt[index] * 3300, 255); + + return sprintf(buf, "%d\n", value); } static ssize_t temp_value_show(struct device *dev, @@ -361,13 +364,15 @@ static ssize_t temp_value_show(struct device *dev, { struct fts_data *data = dev_get_drvdata(dev); int index = to_sensor_dev_attr(devattr)->index; - int err; + int value, err; err = fts_update_device(data); if (err < 0) return err; - return sprintf(buf, "%u\n", data->temp_input[index]); + value = (data->temp_input[index] - 64) * 1000; + + return sprintf(buf, "%d\n", value); } static ssize_t temp_fault_show(struct device *dev, @@ -436,13 +441,15 @@ static ssize_t fan_value_show(struct device *dev, { struct fts_data *data = dev_get_drvdata(dev); int index = to_sensor_dev_attr(devattr)->index; - int err; + int value, err; err = fts_update_device(data); if (err < 0) return err; - return sprintf(buf, "%u\n", data->fan_input[index]); + value = data->fan_input[index] * 60; + + return sprintf(buf, "%d\n", value); } static ssize_t fan_source_show(struct device *dev, -- 2.39.2