From patchwork Thu May 6 07:09:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Nyekjaer X-Patchwork-Id: 12241729 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=-16.0 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, UNWANTED_LANGUAGE_BODY,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 5AAB8C43461 for ; Thu, 6 May 2021 07:10:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DABC61168 for ; Thu, 6 May 2021 07:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233120AbhEFHK4 (ORCPT ); Thu, 6 May 2021 03:10:56 -0400 Received: from first.geanix.com ([116.203.34.67]:43834 "EHLO first.geanix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233116AbhEFHKz (ORCPT ); Thu, 6 May 2021 03:10:55 -0400 Received: from zen.. (unknown [185.17.218.86]) by first.geanix.com (Postfix) with ESMTPSA id DFA3C467C14; Thu, 6 May 2021 07:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=geanix.com; s=first; t=1620284995; bh=jOibTSPS6GfMEalWCAqhIQ4KL1a+okB78aZWmriQ+lg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KxxVfgQzoGmw50+YvlAS+k2qAOsInZqyudtO3UjToJlcJ2psBtv2SbpRT0uZDG6s8 mIc25oNQ5HFwEXELnB14cdr312fLzMgSXbLhL5euoLvRFHcdHgcxlDmOR7GE3khXEz f4yN08Y9dLYzv9mVCNMcSH1B1BkoGWxt2cs3vyM/MzY+1UIs3LKJOPCOmTgVxbjO23 p2MhxLRCCEfJm5KP8jguVt9oAsph6CkhO70UqPRJ0WgyhFoKzbjHd6h3UtQxWddluI hEoAbrb4uYnXQgK1SQu/VMR23zV2CCEsR+yui/G31v2m2q6aKsj/3GskJpdtj9aZ+1 bgSnOdcvkSKgA== 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, tomas.melin@vaisala.com Cc: Sean Nyekjaer Subject: [PATCH v5 6/6] iio: accel: fxls8962af: fix errata bug E3 - I2C burst reads Date: Thu, 6 May 2021 09:09:40 +0200 Message-Id: <20210506070940.312959-6-sean@geanix.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20210506070940.312959-1-sean@geanix.com> References: <20210506070940.312959-1-sean@geanix.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@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 Changes for v5: - added errata function drivers/iio/accel/fxls8962af-core.c | 33 ++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/iio/accel/fxls8962af-core.c b/drivers/iio/accel/fxls8962af-core.c index 889e470658b9..9f4fdddfee41 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 @@ -624,16 +625,42 @@ static const struct iio_buffer_setup_ops fxls8962af_buffer_ops = { .postdisable = fxls8962af_buffer_postdisable, }; +static int fxls8962af_i2c_raw_read_errata3(struct fxls8962af_data *data, + u16 *buffer, int samples, + int sample_length) +{ + int i, ret; + + for (i = 0; i < samples; i++) { + ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, + &buffer[i * 3], sample_length); + if (ret) + return ret; + } + + return ret; +} + static int fxls8962af_fifo_transfer(struct fxls8962af_data *data, u16 *buffer, int samples) { struct device *dev = regmap_get_device(data->regmap); int sample_length = 3 * sizeof(*buffer); - int ret; int total_length = samples * sample_length; + int ret; + + 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.. + */ + ret = fxls8962af_i2c_raw_read_errata3(data, buffer, samples, + sample_length); + else + ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer, + total_length); - ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer, - total_length); if (ret) dev_err(dev, "Error transferring data from fifo: %d\n", ret);