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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 B1B4AC67869 for ; Wed, 12 Dec 2018 00:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77C2E20855 for ; Wed, 12 Dec 2018 00:56:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ONp0a3Ws" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 77C2E20855 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-iio-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726220AbeLLA4Z (ORCPT ); Tue, 11 Dec 2018 19:56:25 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:52910 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726238AbeLLAzu (ORCPT ); Tue, 11 Dec 2018 19:55:50 -0500 Received: by mail-it1-f194.google.com with SMTP id g76so6587968itg.2; Tue, 11 Dec 2018 16:55:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8x3EfAi+dwJT7LG9r3AqAVh9KBm9FxEhlGxf1nFjco4=; b=ONp0a3WsAdCvn6qEPX78E5QC9Mz6d6oRqo1iXX2JUGBV985+YrC2aEi0zru+q7VFfK 6csxPZpiGZhsFx4/ttWg8jxX8prv2ZmZtOYSulIvoDhSAHs2OwBK4J87Jho8O1K43AAX 60hYcWdRVgTjsEmP2KwN/Qz6QCfK2LaYMDZyyFjmmkjupBeKC0RyyzNCkUPXOw+Pk2PV /HsXdOdgZgnijJgsVkq+aFnnoGtwmEUdaYnJu9VoUw51j5JhX05u0bKdBJW8V5pGLgDH A+CQiHENTWdqQ1QUtkoOHWQw+FEdEj3oOXkMZo1yD8gcVMTgWcBB2XLFJc/V6zVgaiYg /Q0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=8x3EfAi+dwJT7LG9r3AqAVh9KBm9FxEhlGxf1nFjco4=; b=d6paOC2xvJ+iXWrVObNlnHWeYIVqADW6oEZEJu6vGjktQt9zXuLQkqDMM52ZGzflyM O+4RQuf00TXmKxVr/bv2ftqxsKDwnnGr2oxlvrDH1ZpNeuj3sgu7jbTTeLtXe13yl+vC nGPQi1Uvku+ORoGXtJBqzdqWu6gxjhBvbTPoN2cf+M/fogewPKswI3dc2SeYkY3A5Kou 4WTkjJhfCR6ykTy7HXy4xjHti4zxwXxq9tp8vlGXypqCtHgMPQGbuihGzAieVf0zcNLO 9bUWV7P8MW80rpn/6Hhmv3f8kqQNpJEoJ7GsGvbs7/as5JQnetP2hx3Reh764oXCfjzL eDjQ== X-Gm-Message-State: AA+aEWaoDInGH14gWcC2S0I5XgzfjXm0E5Fz4iUmVoape9A0julPzxHK 3Ix9gc5KlsC+l2YdQB0cj5w= X-Google-Smtp-Source: AFSGD/U40Oc5azHSTu6+wK0HUW3z50CL3HQhebMK6cXLmPgfP06ZvdgJZnW2t/ruxxoSoludBIfWEw== X-Received: by 2002:a24:1c04:: with SMTP id c4mr4403205itc.79.1544576149095; Tue, 11 Dec 2018 16:55:49 -0800 (PST) Received: from r2700x.localdomain (c-75-70-96-103.hsd1.co.comcast.net. [75.70.96.103]) by smtp.gmail.com with ESMTPSA id l186sm1952445itl.22.2018.12.11.16.55.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Dec 2018 16:55:48 -0800 (PST) From: Jeremy Fertic To: Jonathan Cameron Cc: Lars-Peter Clausen , Michael Hennerich , Hartmut Knaack , Peter Meerwald-Stadler , Greg Kroah-Hartman , linux-iio@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Jeremy Fertic Subject: [PATCH 06/11] staging: iio: adt7316: fix the dac write calculation Date: Tue, 11 Dec 2018 17:54:58 -0700 Message-Id: <20181212005503.28054-7-jeremyfertic@gmail.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181212005503.28054-1-jeremyfertic@gmail.com> References: <20181212005503.28054-1-jeremyfertic@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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. Signed-off-by: Jeremy Fertic --- drivers/staging/iio/addac/adt7316.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/staging/iio/addac/adt7316.c b/drivers/staging/iio/addac/adt7316.c index b7d12d003ddc..77ef3c209b67 100644 --- a/drivers/staging/iio/addac/adt7316.c +++ b/drivers/staging/iio/addac/adt7316.c @@ -1442,7 +1442,7 @@ static ssize_t adt7316_show_DAC(struct adt7316_chip_info *chip, 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; @@ -1460,9 +1460,13 @@ static ssize_t adt7316_store_DAC(struct adt7316_chip_info *chip, 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; } -- 2.19.1