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=-10.5 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=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 B90D9C43387 for ; Fri, 11 Jan 2019 14:46:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FEE9206B6 for ; Fri, 11 Jan 2019 14:46:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217989; bh=ovmtQlXGn31Rhr/kBzg0WxGis0FDsQeCTnXf2timqLA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=b2DdN7uPOE3XFUfICD/bkQmfiE1hWRho6QPitMnC+k6pW3jnoxGycg698YdDwRNTQ y82D0XaTOFwc47vUvZh3cUPVGT7n7Vodc34B7V32Ll+MOAGRnPfhvHh5LlaU+a/Cyx dx4pR7tWBOBvBPEvEUYXNvkjtBqNUSk07OkB8Keg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391464AbfAKOq2 (ORCPT ); Fri, 11 Jan 2019 09:46:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:36130 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404340AbfAKOnP (ORCPT ); Fri, 11 Jan 2019 09:43:15 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 A61F821848; Fri, 11 Jan 2019 14:43:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217794; bh=ovmtQlXGn31Rhr/kBzg0WxGis0FDsQeCTnXf2timqLA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wvYju3mQVU2PlPriN5QFluCeevHQkTZMReJoj4u1f/pj2aoCNB356nH+O901dO/U0 TioUjijSlFP8rSyDsXYK2AxWBgEn3uQ4w/t/RMlOLS9Y2PaLojrOJARebxCnxeDxSL Mg/A0DtgC3m9e4g3m/x3rMRWN63ObNCc7FdQY/o4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mircea Caprioru , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 4.20 44/65] iio: dac: ad5686: fix bit shift read register Date: Fri, 11 Jan 2019 15:15:30 +0100 Message-Id: <20190111131102.416207544@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111131055.331350141@linuxfoundation.org> References: <20190111131055.331350141@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mircea Caprioru commit 0e76df5c978338f3051e5126fc0c4245c57a307a upstream. This patch solves the register readback issue with the bit shift. When the dac resolution was lower than the register size (ex. 12 bits out of 16 bits) the readback value was not shifted with the difference in bits and the value was higher. Also a mask is applied on the read value in order to get the value relative to the actual bit size. Fixes: 0357e488b8 ("iio:dac:ad5686: Refactor the driver") Signed-off-by: Mircea Caprioru Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/dac/ad5686.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/iio/dac/ad5686.c +++ b/drivers/iio/dac/ad5686.c @@ -124,7 +124,8 @@ static int ad5686_read_raw(struct iio_de mutex_unlock(&indio_dev->mlock); if (ret < 0) return ret; - *val = ret; + *val = (ret >> chan->scan_type.shift) & + GENMASK(chan->scan_type.realbits - 1, 0); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = st->vref_mv;