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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 680A2C48BDE for ; Sun, 7 Jul 2019 19:38:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 481E420651 for ; Sun, 7 Jul 2019 19:38:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727697AbfGGTiT (ORCPT ); Sun, 7 Jul 2019 15:38:19 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56854 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727458AbfGGTiB (ORCPT ); Sun, 7 Jul 2019 15:38:01 -0400 Received: from 94.197.121.43.threembb.co.uk ([94.197.121.43] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hkCz1-0006da-Fh; Sun, 07 Jul 2019 20:37:59 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hkCz0-0005XX-Bv; Sun, 07 Jul 2019 20:37:58 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Jeremy Fertic" , "Jonathan Cameron" Date: Sun, 07 Jul 2019 17:54:17 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 016/129] staging: iio: adt7316: fix the dac read calculation In-Reply-To: X-SA-Exim-Connect-IP: 94.197.121.43 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Fertic commit 45130fb030aec26ac28b4bb23344901df3ec3b7f upstream. The calculation of the current dac value is using the wrong bits of the dac lsb register. Create two macros to shift the lsb register value into lsb position, depending on whether the dac is 10 or 12 bit. Initialize data to 0 so, with an 8 bit dac, the msb register value can be bitwise ORed with data. 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: Ben Hutchings --- drivers/staging/iio/addac/adt7316.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/staging/iio/addac/adt7316.c +++ b/drivers/staging/iio/addac/adt7316.c @@ -47,6 +47,8 @@ #define ADT7516_MSB_AIN3 0xA #define ADT7516_MSB_AIN4 0xB #define ADT7316_DA_DATA_BASE 0x10 +#define ADT7316_DA_10_BIT_LSB_SHIFT 6 +#define ADT7316_DA_12_BIT_LSB_SHIFT 4 #define ADT7316_DA_MSB_DATA_REGS 4 #define ADT7316_LSB_DAC_A 0x10 #define ADT7316_MSB_DAC_A 0x11 @@ -1409,7 +1411,7 @@ static IIO_DEVICE_ATTR(ex_analog_temp_of static ssize_t adt7316_show_DAC(struct adt7316_chip_info *chip, int channel, char *buf) { - u16 data; + u16 data = 0; u8 msb, lsb, offset; int ret; @@ -1434,7 +1436,11 @@ static ssize_t adt7316_show_DAC(struct a if (ret) return -EIO; - data = (msb << offset) + (lsb & ((1 << offset) - 1)); + if (chip->dac_bits == 12) + data = lsb >> ADT7316_DA_12_BIT_LSB_SHIFT; + else if (chip->dac_bits == 10) + data = lsb >> ADT7316_DA_10_BIT_LSB_SHIFT; + data |= msb << offset; return sprintf(buf, "%d\n", data); }