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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 D8F84C2D0DB for ; Tue, 28 Jan 2020 14:31:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A7E4E2467E for ; Tue, 28 Jan 2020 14:31:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221900; bh=GWxwkadIlVobGboLxGw+xsL9+RnjZssd4gllY72ToZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Jgs0sFx/QXJ79OL85mypbufVbOTF1/xrvMMkd7J3JbgiknqvWgPITgaMakgRnUW5s xdnreau4sHIAahRvq0CvGMkXooyP0gvG8dQTd987k7rHIh9vatxPNF08VLxcXyQ+8y Uxa3TPRVtog8qoB4k3+NXbUzne0D8b1k9zdH+St8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387636AbgA1Obk (ORCPT ); Tue, 28 Jan 2020 09:31:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:55484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733309AbgA1O1l (ORCPT ); Tue, 28 Jan 2020 09:27:41 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 16017207FD; Tue, 28 Jan 2020 14:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221660; bh=GWxwkadIlVobGboLxGw+xsL9+RnjZssd4gllY72ToZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IGPz0bEyvywilTfliHEN2qt1Z6Mqb6uCbmyyp7FCV70Y2yZsWMhjxOvhk1tJQqUMJ BQ3KP5LQOkEemztqjXA+9vBgQ52OpkaROtRoCT7OBny1LHpzhTwZ+NN0ahEuzvNkpI 8c/RXgbKRLmBKh0VpE1XlqsuvYLLQmEQM+vJSPDs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Luuk Paulussen , Guenter Roeck Subject: [PATCH 4.19 23/92] hwmon: (adt7475) Make volt2reg return same reg as reg2volt input Date: Tue, 28 Jan 2020 15:07:51 +0100 Message-Id: <20200128135812.082497945@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135809.344954797@linuxfoundation.org> References: <20200128135809.344954797@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Luuk Paulussen commit cf3ca1877574a306c0207cbf7fdf25419d9229df upstream. reg2volt returns the voltage that matches a given register value. Converting this back the other way with volt2reg didn't return the same register value because it used truncation instead of rounding. This meant that values read from sysfs could not be written back to sysfs to set back the same register value. With this change, volt2reg will return the same value for every voltage previously returned by reg2volt (for the set of possible input values) Signed-off-by: Luuk Paulussen Link: https://lore.kernel.org/r/20191205231659.1301-1-luuk.paulussen@alliedtelesis.co.nz cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/adt7475.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/hwmon/adt7475.c +++ b/drivers/hwmon/adt7475.c @@ -296,9 +296,10 @@ static inline u16 volt2reg(int channel, long reg; if (bypass_attn & (1 << channel)) - reg = (volt * 1024) / 2250; + reg = DIV_ROUND_CLOSEST(volt * 1024, 2250); else - reg = (volt * r[1] * 1024) / ((r[0] + r[1]) * 2250); + reg = DIV_ROUND_CLOSEST(volt * r[1] * 1024, + (r[0] + r[1]) * 2250); return clamp_val(reg, 0, 1023) & (0xff << 2); }