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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 2028AC04E53 for ; Wed, 15 May 2019 12:20:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E58CF20578 for ; Wed, 15 May 2019 12:20:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557922823; bh=ipuEa8aJPjDJRCZlmwpV+28D1V67eu0XO6csauo0Slo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=D6+zwbyMikxnn2F6cj7qaOOIP1q2ddB016UY7bibFOYvYlM/dbkFpewPao1+/Jlm7 IMSWWlI3XVd5ZuAFDF+YsTgVn8D4B4ZRnzQtg08B79688DbeoPgFZb9e0dfJtrOQVh FrARNGNsMooE+wfK10IRsqemgCKkdIHd52Qceip4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727045AbfEOMUQ (ORCPT ); Wed, 15 May 2019 08:20:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:56476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726727AbfEOK7t (ORCPT ); Wed, 15 May 2019 06:59:49 -0400 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 1F94F216FD; Wed, 15 May 2019 10:59:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557917988; bh=ipuEa8aJPjDJRCZlmwpV+28D1V67eu0XO6csauo0Slo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nv4McBhm6kqIYn26mp0yQ4AbCfLDr7H0jS+rJB8K052rUH126EFeftFOVsT+Kzjry 3s0bylysnYAnP1rAjOq4RS+0WTkYD1+2jwrPBBy6HDqUOnSjAIERDiMvM6a/YTPlG7 VCI8w40h230HTweDACYZj3gcujURJ1BmDm/a2Lzk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeremy Fertic , Jonathan Cameron Subject: [PATCH 3.18 50/86] staging: iio: adt7316: fix the dac write calculation Date: Wed, 15 May 2019 12:55:27 +0200 Message-Id: <20190515090652.323314440@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090642.339346723@linuxfoundation.org> References: <20190515090642.339346723@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jeremy Fertic commit 78accaea117c1ae878774974fab91ac4a0b0e2b0 upstream. The lsb calculation is not masking the correct bits from the user input. Subtract 1 from (1 << offset) to correctly set up the mask to be applied to user input. The lsb register stores its value starting at the bit 7 position. adt7316_store_DAC() currently assumes the value is at the other end of the register. Shift the lsb value before storing it in a new variable lsb_reg, and write this variable to the lsb register. Fixes: 35f6b6b86ede ("staging: iio: new ADT7316/7/8 and ADT7516/7/9 driver") Signed-off-by: Jeremy Fertic Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/addac/adt7316.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/staging/iio/addac/adt7316.c +++ b/drivers/staging/iio/addac/adt7316.c @@ -1453,7 +1453,7 @@ static ssize_t adt7316_show_DAC(struct a static ssize_t adt7316_store_DAC(struct adt7316_chip_info *chip, int channel, const char *buf, size_t len) { - u8 msb, lsb, offset; + u8 msb, lsb, lsb_reg, offset; u16 data; int ret; @@ -1471,9 +1471,13 @@ static ssize_t adt7316_store_DAC(struct return -EINVAL; if (chip->dac_bits > 8) { - lsb = data & (1 << offset); + lsb = data & ((1 << offset) - 1); + if (chip->dac_bits == 12) + lsb_reg = lsb << ADT7316_DA_12_BIT_LSB_SHIFT; + else + lsb_reg = lsb << ADT7316_DA_10_BIT_LSB_SHIFT; ret = chip->bus.write(chip->bus.client, - ADT7316_DA_DATA_BASE + channel * 2, lsb); + ADT7316_DA_DATA_BASE + channel * 2, lsb_reg); if (ret) return -EIO; }