From patchwork Thu Apr 29 12:28:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Nyekjaer X-Patchwork-Id: 430005 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 8A584C43616 for ; Thu, 29 Apr 2021 12:28:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 583DC613F9 for ; Thu, 29 Apr 2021 12:28:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233731AbhD2M3K (ORCPT ); Thu, 29 Apr 2021 08:29:10 -0400 Received: from first.geanix.com ([116.203.34.67]:50676 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234147AbhD2M3J (ORCPT ); Thu, 29 Apr 2021 08:29:09 -0400 Received: from zen.. (unknown [185.17.218.86]) by first.geanix.com (Postfix) with ESMTPSA id 44643466699; Thu, 29 Apr 2021 12:28:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1619699301; bh=f/d1enRQkRJtaWSp6G4i9eygpUWyG+QO1k1J0/b1mUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UZFkm3VZZSqlK/ZlgbwjrRGuYFYypskBV/S3n7vcWp2HEZ9B2ZUH0+MM3W+JFAb7U L5+VoEMzz8aJakD6bZUaMG9spv1QudgXYLaJXR1DAsI29Pbw0QLXqvsILRpiicvMXu uGlawLcn5Y4pgstDkJEAjraWbC3TadbCROwmsZh3Qlrwpla8yCtxZBWvdrFdGPY5pJ xhNksduUP27unN4gYbUvq9xImXlNAd60gFkhEbNDmlMU7Kn+ylauC9p8OnAe5Hc17O Llixt4Yjgvey0qBkb2oMbS30h8IkA1NgQ01d2E4nqn2rORwG4PK0++egC/NveHpYCl i6c3Tq/Eag9wg== From: Sean Nyekjaer To: jic23@kernel.org, linux-iio@vger.kernel.org, andy.shevchenko@gmail.com, lars@metafoo.de, Nuno.Sa@analog.com, robh+dt@kernel.org, devicetree@vger.kernel.org Cc: Sean Nyekjaer Subject: [PATCH v4 6/6] iio: accel: fxls8962af: fix errata bug E3 - I2C burst reads Date: Thu, 29 Apr 2021 14:28:06 +0200 Message-Id: <20210429122806.3814330-6-sean@geanix.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210429122806.3814330-1-sean@geanix.com> References: <20210429122806.3814330-1-sean@geanix.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org When flushing the hw fifo there is a bug in the I2C that prevents burst reads of more than one sample pair. Signed-off-by: Sean Nyekjaer --- Changes from RFC: - using i2c_verify_client() to detect if hw is connected on I2C bus drivers/iio/accel/fxls8962af-core.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/iio/accel/fxls8962af-core.c b/drivers/iio/accel/fxls8962af-core.c index 2e863ef71a7d..e45c9e88bf6e 100644 --- a/drivers/iio/accel/fxls8962af-core.c +++ b/drivers/iio/accel/fxls8962af-core.c @@ -14,6 +14,7 @@ #include #include +#include #include #include #include @@ -631,11 +632,28 @@ static int fxls8962af_fifo_transfer(struct fxls8962af_data *data, { struct device *dev = regmap_get_device(data->regmap); int sample_length = 3 * sizeof(*buffer); - int ret; + int ret, i; int total_length = samples * sample_length; - ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer, - total_length); + if (i2c_verify_client(dev)) { + /* + * Due to errata bug: + * E3: FIFO burst read operation error using I2C interface + * We have to avoid burst reads on I2C.. + */ + for (i = 0; i < samples; i++) { + ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, + &buffer[i], + sample_length); + if (ret < 0) + goto out; + } + } else { + ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer, + total_length); + } + + out: if (ret < 0) dev_err(dev, "Error transferring data from fifo: %d\n", ret);