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,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 135A5C43387 for ; Fri, 11 Jan 2019 14:46:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2523206B6 for ; Fri, 11 Jan 2019 14:46:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547217992; bh=ovmtQlXGn31Rhr/kBzg0WxGis0FDsQeCTnXf2timqLA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Rz9JZKF1rPd2czrL0hJ+Uy0zZpOXXEF6hDQ+vw2DZ4UlGw5G316QFaPwA97w4ZMPB cPJvnkKjgsWPbb/3ynNZMEX2OE2IgRUHgeFkuDRVZf/t1ne/tKzUOaikbXXgt7u3QP b8t7z5BqlafpnfLphdRD6xwvq+QAJHP6jmmjwOwo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391453AbfAKOqZ (ORCPT ); Fri, 11 Jan 2019 09:46:25 -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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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;