From patchwork Tue Sep 13 07:34:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nuno Sa X-Patchwork-Id: 12974505 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CBF2C54EE9 for ; Tue, 13 Sep 2022 07:33:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230044AbiIMHdi (ORCPT ); Tue, 13 Sep 2022 03:33:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230414AbiIMHde (ORCPT ); Tue, 13 Sep 2022 03:33:34 -0400 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 106B359269 for ; Tue, 13 Sep 2022 00:33:31 -0700 (PDT) Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28D6GEi8010444; Tue, 13 Sep 2022 03:33:17 -0400 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3jgqg5tyjq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 13 Sep 2022 03:33:17 -0400 Received: from ASHBMBX9.ad.analog.com (ASHBMBX9.ad.analog.com [10.64.17.10]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 28D7XG5V035750 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 13 Sep 2022 03:33:16 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.14; Tue, 13 Sep 2022 03:33:15 -0400 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server id 15.2.986.14 via Frontend Transport; Tue, 13 Sep 2022 03:33:15 -0400 Received: from nsa.ad.analog.com ([10.44.3.57]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 28D7WuNP002761; Tue, 13 Sep 2022 03:33:02 -0400 From: =?utf-8?q?Nuno_S=C3=A1?= To: CC: Michael Hennerich , Lars-Peter Clausen , Jonathan Cameron , Michael Hennerich Subject: [PATCH 1/2] iio: dac: ad5593r: Fix i2c read protocol requirements Date: Tue, 13 Sep 2022 09:34:12 +0200 Message-ID: <20220913073413.140475-2-nuno.sa@analog.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913073413.140475-1-nuno.sa@analog.com> References: <20220913073413.140475-1-nuno.sa@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: kbz2ZlBDqGqAB4s3dtbaqcePQucgntjX X-Proofpoint-ORIG-GUID: kbz2ZlBDqGqAB4s3dtbaqcePQucgntjX X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-13_02,2022-09-12_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxscore=0 malwarescore=0 mlxlogscore=813 clxscore=1015 priorityscore=1501 lowpriorityscore=0 adultscore=0 suspectscore=0 impostorscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2209130033 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Michael Hennerich For reliable operation across the full range of supported interface rates, the AD5593R needs a STOP condition between address write, and data read (like show in the datasheet Figure 40) so in turn i2c_smbus_read_word_swapped cannot be used. While at it, a simple helper was added to make the code simpler. Fixes: 56ca9db862bf ("iio: dac: Add support for the AD5592R/AD5593R ADCs/DACs") Signed-off-by: Michael Hennerich Signed-off-by: Nuno Sá --- drivers/iio/dac/ad5593r.c | 44 +++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 20 deletions(-) diff --git a/drivers/iio/dac/ad5593r.c b/drivers/iio/dac/ad5593r.c index 34e1319a9712..43ee4efb250c 100644 --- a/drivers/iio/dac/ad5593r.c +++ b/drivers/iio/dac/ad5593r.c @@ -20,6 +20,24 @@ #define AD5593R_MODE_GPIO_READBACK (6 << 4) #define AD5593R_MODE_REG_READBACK (7 << 4) +static int ad5593r_read_word(struct i2c_client *i2c, u8 reg, u16 *value) +{ + int ret; + u8 buf[2]; + + ret = i2c_smbus_write_byte(i2c, reg); + if (ret < 0) + return ret; + + ret = i2c_master_recv(i2c, buf, sizeof(buf)); + if (ret < 0) + return ret; + + *value = get_unaligned_be16(buf); + + return 0; +} + static int ad5593r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value) { struct i2c_client *i2c = to_i2c_client(st->dev); @@ -38,13 +56,7 @@ static int ad5593r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value) if (val < 0) return (int) val; - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_ADC_READBACK); - if (val < 0) - return (int) val; - - *value = (u16) val; - - return 0; + return ad5593r_read_word(i2c, AD5593R_MODE_ADC_READBACK, value); } static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) @@ -58,29 +70,21 @@ static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value) static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value) { struct i2c_client *i2c = to_i2c_client(st->dev); - s32 val; - - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_REG_READBACK | reg); - if (val < 0) - return (int) val; - - *value = (u16) val; - return 0; + return ad5593r_read_word(i2c, AD5593R_MODE_REG_READBACK | reg, value); } static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value) { struct i2c_client *i2c = to_i2c_client(st->dev); - s32 val; + u16 val; + int ret; - val = i2c_smbus_read_word_swapped(i2c, AD5593R_MODE_GPIO_READBACK); - if (val < 0) - return (int) val; + ret = ad5593r_read_word(i2c, AD5593R_MODE_GPIO_READBACK, &val); *value = (u8) val; - return 0; + return ret; } static const struct ad5592r_rw_ops ad5593r_rw_ops = {