From patchwork Mon May 17 14:03:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 440612 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 95FDDC433B4 for ; Mon, 17 May 2021 15:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EB0261004 for ; Mon, 17 May 2021 15:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244709AbhEQPkj (ORCPT ); Mon, 17 May 2021 11:40:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:40288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244507AbhEQPio (ORCPT ); Mon, 17 May 2021 11:38:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9733F61CFA; Mon, 17 May 2021 14:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621262453; bh=3d+IWm9c/O8sHKIwBHAISjeRkekeqprqysvOxnSGRLc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kPaAEWWtAbeSX4gMiuODPUQylwMwvxFsu2hmyisk3ynMIUxw4frR/v4O2XGs9cGAM gW249x/ASKUDIG3Q6G+w47mbvIbEZIue4q9o7SacHzGzaKuCQf7Im090n7eXivKTiO +5viReRpGtVnmPnP6ORPUKzZqZwLKNeMb/bvCQG4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Svyatoslav Ryhel , Andy Shevchenko , Linus Walleij , Dmitry Osipenko , Jean-Baptiste Maneyrol , Jonathan Cameron , Maxim Schwalm Subject: [PATCH 5.11 294/329] iio: gyro: mpu3050: Fix reported temperature value Date: Mon, 17 May 2021 16:03:25 +0200 Message-Id: <20210517140312.050626750@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210517140302.043055203@linuxfoundation.org> References: <20210517140302.043055203@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dmitry Osipenko commit f73c730774d88a14d7b60feee6d0e13570f99499 upstream. The raw temperature value is a 16-bit signed integer. The sign casting is missing in the code, which results in a wrong temperature reported by userspace tools, fix it. Cc: stable@vger.kernel.org Fixes: 3904b28efb2c ("iio: gyro: Add driver for the MPU-3050 gyroscope") Datasheet: https://www.cdiweb.com/datasheets/invensense/mpu-3000a.pdf Tested-by: Maxim Schwalm # Asus TF700T Tested-by: Svyatoslav Ryhel # Asus TF201 Reported-by: Svyatoslav Ryhel Reviewed-by: Andy Shevchenko Reviewed-by: Linus Walleij Signed-off-by: Dmitry Osipenko Acked-by: Jean-Baptiste Maneyrol Link: https://lore.kernel.org/r/20210423020959.5023-1-digetx@gmail.com Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/gyro/mpu3050-core.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/iio/gyro/mpu3050-core.c +++ b/drivers/iio/gyro/mpu3050-core.c @@ -272,7 +272,16 @@ static int mpu3050_read_raw(struct iio_d case IIO_CHAN_INFO_OFFSET: switch (chan->type) { case IIO_TEMP: - /* The temperature scaling is (x+23000)/280 Celsius */ + /* + * The temperature scaling is (x+23000)/280 Celsius + * for the "best fit straight line" temperature range + * of -30C..85C. The 23000 includes room temperature + * offset of +35C, 280 is the precision scale and x is + * the 16-bit signed integer reported by hardware. + * + * Temperature value itself represents temperature of + * the sensor die. + */ *val = 23000; return IIO_VAL_INT; default: @@ -329,7 +338,7 @@ static int mpu3050_read_raw(struct iio_d goto out_read_raw_unlock; } - *val = be16_to_cpu(raw_val); + *val = (s16)be16_to_cpu(raw_val); ret = IIO_VAL_INT; goto out_read_raw_unlock;