From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A12D46D543; Tue, 29 Sep 2026 22:43:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.135.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790721816; cv=none; b=Vk4zPhV3PXJFwZAOf76mX+yYbFwpvoieuizDMKM1acaVsUZjsciviTKKPDu0xGQvzqiOjCKpE7TKbHeKNTAkStZeXkPtGrim0YzWMLS/cM5MYuFYKXkFjAIkgwSUlhepHQPAkAoqREuKxJaM/wmbGwn9oNpAt999pMB1V85p6EE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790721816; c=relaxed/simple; bh=gorqy/M7z1+MFpxAlku5rBk3gPpe7evn3aAYnpBtEhk=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FB6WtpjN4BhuDzh9wuzOon6UP2lzqOOtB7wFfSSHmu5VT9ULAU+lxMeIU7TKjdngvtz5jSwk9EWfKwQHtf3IBsnUac9Lkav+0TBwS7D5Cv26S+7I4eX89rgsyPMTNdvSMEi9niSXVtiYcWZqvPAAfLCvF8wcTXH1s5pQC9Nx7Pc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=analog.com; spf=pass smtp.mailfrom=analog.com; dkim=pass (2048-bit key) header.d=analog.com header.i=@analog.com header.b=AgENymS0; arc=none smtp.client-ip=148.163.135.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=analog.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=analog.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=analog.com header.i=@analog.com header.b="AgENymS0" Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 68TJn2011957991; Tue, 29 Sep 2026 18:43:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=analog.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=DKIM; bh=V2Uju a7vkuEfgCjaplUWkCDsIw8ezk7O6Stue/m/TOc=; b=AgENymS0eaBP7RRb+Fwrz xi5sTS80MSB2umISxFlFaSyL8XV2M2BCOKKhmvh/QcnDUjSCSbXcLqziswMubWOW KdW4VMPrWazOXF9YEe7oX/DTWNcWy7Aijj6SIih7pFScP6LXKbZtFiA093Uwfl01 nQFg/ayjZO8PRwmSHqob4gLG7O9ZJ5ISOeHNx7MVaaTOdkXythrHLaHvYvh7pGHB gq89s8k+xx4cHnpbPIt8NCF/9KeT8B8oi/YrRmgEnO55huwmBbaglzFMtWyIesYO nnd5w4kUXUZcRhiEGZvxa0L7Vw7I++qQcmZjPFo1bFkVpf3Q4e3ORLA3h08TJyjc A== Received: from nwd2mta3.analog.com ([137.71.173.56]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 4gyy3vfg1e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 29 Sep 2026 18:43:29 -0400 (EDT) Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta3.analog.com (8.14.7/8.14.7) with ESMTP id 68TMhScV041441 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 29 Sep 2026 18:43:28 -0400 Received: from ASHBCASHYB5.ad.analog.com (10.64.17.133) by ASHBMBX8.ad.analog.com (10.64.17.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.37; Tue, 29 Sep 2026 18:43:28 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) by ASHBCASHYB5.ad.analog.com (10.64.17.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.37; Tue, 29 Sep 2026 18:43:28 -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 15.2.1748.37 via Frontend Transport; Tue, 29 Sep 2026 18:43:28 -0400 Received: from work.maxim-ic.internal ([10.66.6.191]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 68TMhCm0008184; Tue, 29 Sep 2026 18:43:14 -0400 From: Marcelo Schmitt To: , , , CC: , , , , , , , , , , , Andy Shevchenko Subject: [PATCH v3 04/13] iio: adc: ad4134: Serialize single-read operations Date: Tue, 29 Sep 2026 19:43:06 -0300 Message-ID: <1c61961b502fc26a08e43d287c94609feb60649d.1790719424.git.marcelo.schmitt@analog.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: dfvPg3nGATp3iYyZaf2iQrAEzdPlyV1J X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTI5MDA5MCBTYWx0ZWRfX35dKvk2jeAMd 1V7Ws6wWiB1aB7nVSqykSwdUwQqn12U6iM8YE0KuWd8p+Oy23A/O81e8yAednP0jgUxNDjNg02g bBQDEQbUG/HdEkW4UYQvFdJ6q2ymwinezd+zu08OkJS40vjl3g709tmwuPQVp3g0aw97PLgmXko 9wk6qQvspHP0C/NR301EBImHI9gnCwvJRMBQn1A+nj4s73jMSSUpcp0BEPkw4MVt9aad5DmlDha 0sScuZNU24FIsxDXbx623GyoCKH1JlWRjuzmrNEzcoEmjNmBjDLkvT36DDi7NpEBIzn2EdbBfJ9 M5gVGYhbtJRv0r47rZvSz+KAtBcw/FQ6fHYUKDdVzJSyYV5ze9O8fNEzfZZJVW227GQrpHXjXIe PeLaLJYmkj+I62vfNFZolbEYm6F7SmOVp/+2jqnlM52h7+y+1q6Q8w6wrzNqvMDBUHJ6NBxzmeI RiuM7L9Eo/UbD646mVA== X-Authority-Analysis: v=2.4 cv=Y/ltIReN c=1 sm=1 tr=0 ts=6abc3f11 cx=c_pps a=PpDZqlmH/M8setHirZLBMw==:117 a=PpDZqlmH/M8setHirZLBMw==:17 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=0sLvza09kfJOxVLZPwjg:22 a=Z0pTeXoby7EwIRygza74:22 a=QyXUC8HyAAAA:8 a=gAnH3GRIAAAA:8 a=lQRJhboXyqThIMNCO80A:9 X-Proofpoint-Spam-Info: AW1haW4tMjYwOTI5MDA5MCBTYWx0ZWRfX1djHsvQRDLSh MQ7foWd6qD46fqOwawaktVLqYsV8bBpPWgrt5E2CruE8AWilZgZyGLM1PfvTvecYwR2It6TbjRX Fwp/+PMQ4MmVNyJ1iNo+DbIKaHtVQZyYpizZNLdZVRyyDmDrsDWc X-Proofpoint-ORIG-GUID: dfvPg3nGATp3iYyZaf2iQrAEzdPlyV1J X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-29_04,2026-09-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 lowpriorityscore=0 adultscore=0 suspectscore=0 impostorscore=0 spamscore=0 malwarescore=0 bulkscore=0 priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609290090 Protect single-sample read operations from going wrong if two or more of them run concurrently. Serialize the data read operation so to avoid single-sample read requests disrupting each other. Reviewed-by: Andy Shevchenko Signed-off-by: Marcelo Schmitt --- Change log v2 -> v3: - Renamed the mutex so it has a more distinguishable name from the mutex to be added on a follow up patch. drivers/iio/adc/ad4134.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/ad4134.c b/drivers/iio/adc/ad4134.c index 4c8adb8efe4e..db3cf69401f6 100644 --- a/drivers/iio/adc/ad4134.c +++ b/drivers/iio/adc/ad4134.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -15,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -98,6 +100,11 @@ struct ad4134_state { struct regmap *regmap; unsigned long sys_clk_hz; struct gpio_desc *odr_gpio; + /* + * Synchronize access to members the of device state, and ensure + * atomicity of consecutive register access operations. + */ + struct mutex sync_lock; int refin_mv; /* * DMA (thus cache coherency maintenance) requires the transfer buffers @@ -257,7 +264,9 @@ static int ad4134_read_raw(struct iio_dev *indio_dev, int ret; switch (info) { - case IIO_CHAN_INFO_RAW: + case IIO_CHAN_INFO_RAW: { + guard(mutex)(&st->sync_lock); + gpiod_set_value_cansleep(st->odr_gpio, 1); /* * For slave mode gated DCLK (data sheet page 11), the minimum @@ -276,6 +285,7 @@ static int ad4134_read_raw(struct iio_dev *indio_dev, return ret; return IIO_VAL_INT; + } case IIO_CHAN_INFO_SCALE: *val = st->refin_mv; *val2 = AD4134_CHAN_PRECISION_BITS - 1; @@ -444,6 +454,10 @@ static int ad4134_probe(struct spi_device *spi) crc8_populate_msb(ad4134_spi_crc_table, AD4134_SPI_CRC_POLYNOM); + ret = devm_mutex_init(dev, &st->sync_lock); + if (ret) + return ret; + st->regmap = devm_regmap_init(dev, NULL, st, &ad4134_regmap_config); if (IS_ERR(st->regmap)) return dev_err_probe(dev, PTR_ERR(st->regmap), -- 2.53.0