From patchwork Wed Dec 9 23:48:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Belloni X-Patchwork-Id: 11962893 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5287EC433FE for ; Wed, 9 Dec 2020 23:52:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B21B23B53 for ; Wed, 9 Dec 2020 23:52:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730301AbgLIXvn (ORCPT ); Wed, 9 Dec 2020 18:51:43 -0500 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:39817 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732493AbgLIXtz (ORCPT ); Wed, 9 Dec 2020 18:49:55 -0500 X-Originating-IP: 86.194.74.19 Received: from localhost (lfbn-lyo-1-997-19.w86-194.abo.wanadoo.fr [86.194.74.19]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 797F3240007; Wed, 9 Dec 2020 23:49:07 +0000 (UTC) From: Alexandre Belloni To: Jonathan Cameron Cc: Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 4/6] iio:common:ms_sensors:ms_sensors_i2c: rework CRC calculation helper Date: Thu, 10 Dec 2020 00:48:55 +0100 Message-Id: <20201209234857.1521453-5-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201209234857.1521453-1-alexandre.belloni@bootlin.com> References: <20201209234857.1521453-1-alexandre.belloni@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org The CRC calculation always happens on 8 words which is why there is an extra element in the prom array of struct ms_tp_dev. However, on ms5637 and similar, only 7 words are readable. Then, set MS_SENSORS_TP_PROM_WORDS_NB to 8 and stop passing a len parameter to ms_sensors_tp_crc_valid as this simply hide the fact that it is hardcoded. Finally, use the newly introduced hw->prom_len to know how many words can be read. Signed-off-by: Alexandre Belloni --- drivers/iio/common/ms_sensors/ms_sensors_i2c.c | 12 +++++------- drivers/iio/common/ms_sensors/ms_sensors_i2c.h | 4 ++-- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/iio/common/ms_sensors/ms_sensors_i2c.c b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c index b9e2038d05ef..872f90459e2e 100644 --- a/drivers/iio/common/ms_sensors/ms_sensors_i2c.c +++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.c @@ -493,19 +493,18 @@ EXPORT_SYMBOL(ms_sensors_ht_read_humidity); * This function is only used when reading PROM coefficients * * @prom: pointer to PROM coefficients array - * @len: length of PROM coefficients array * * Return: True if CRC is ok. */ -static bool ms_sensors_tp_crc_valid(u16 *prom, u8 len) +static bool ms_sensors_tp_crc_valid(u16 *prom) { unsigned int cnt, n_bit; u16 n_rem = 0x0000, crc_read = prom[0], crc = (*prom & 0xF000) >> 12; - prom[len - 1] = 0; + prom[MS_SENSORS_TP_PROM_WORDS_NB - 1] = 0; prom[0] &= 0x0FFF; /* Clear the CRC computation part */ - for (cnt = 0; cnt < len * 2; cnt++) { + for (cnt = 0; cnt < MS_SENSORS_TP_PROM_WORDS_NB * 2; cnt++) { if (cnt % 2 == 1) n_rem ^= prom[cnt >> 1] & 0x00FF; else @@ -537,7 +536,7 @@ int ms_sensors_tp_read_prom(struct ms_tp_dev *dev_data) { int i, ret; - for (i = 0; i < MS_SENSORS_TP_PROM_WORDS_NB; i++) { + for (i = 0; i < dev_data->hw->prom_len; i++) { ret = ms_sensors_read_prom_word( dev_data->client, MS_SENSORS_TP_PROM_READ + (i << 1), @@ -547,8 +546,7 @@ int ms_sensors_tp_read_prom(struct ms_tp_dev *dev_data) return ret; } - if (!ms_sensors_tp_crc_valid(dev_data->prom, - MS_SENSORS_TP_PROM_WORDS_NB + 1)) { + if (!ms_sensors_tp_crc_valid(dev_data->prom)) { dev_err(&dev_data->client->dev, "Calibration coefficients crc check error\n"); return -ENODEV; diff --git a/drivers/iio/common/ms_sensors/ms_sensors_i2c.h b/drivers/iio/common/ms_sensors/ms_sensors_i2c.h index f4a88148c113..f15b973f27c6 100644 --- a/drivers/iio/common/ms_sensors/ms_sensors_i2c.h +++ b/drivers/iio/common/ms_sensors/ms_sensors_i2c.h @@ -11,7 +11,7 @@ #include #include -#define MS_SENSORS_TP_PROM_WORDS_NB 7 +#define MS_SENSORS_TP_PROM_WORDS_NB 8 /** * struct ms_ht_dev - Humidity/Temperature sensor device structure @@ -47,7 +47,7 @@ struct ms_tp_dev { struct i2c_client *client; struct mutex lock; const struct ms_tp_hw_data *hw; - u16 prom[MS_SENSORS_TP_PROM_WORDS_NB + 1]; + u16 prom[MS_SENSORS_TP_PROM_WORDS_NB]; u8 res_index; };