From patchwork Thu Feb 7 21:50:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brandon Maier X-Patchwork-Id: 10802183 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 48CB113A4 for ; Thu, 7 Feb 2019 22:00:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 380AF2E369 for ; Thu, 7 Feb 2019 22:00:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2C1F42E36A; Thu, 7 Feb 2019 22:00:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9F63B2E377 for ; Thu, 7 Feb 2019 22:00:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726873AbfBGWAQ (ORCPT ); Thu, 7 Feb 2019 17:00:16 -0500 Received: from da1vs03.rockwellcollins.com ([205.175.227.47]:58843 "EHLO da1vs03.rockwellcollins.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727078AbfBGWAQ (ORCPT ); Thu, 7 Feb 2019 17:00:16 -0500 X-Greylist: delayed 566 seconds by postgrey-1.27 at vger.kernel.org; Thu, 07 Feb 2019 17:00:15 EST Received: from ofwda1n02.rockwellcollins.com (HELO dtulimr01.rockwellcollins.com) ([205.175.227.14]) by da1vs03.rockwellcollins.com with ESMTP; 07 Feb 2019 15:50:49 -0600 X-Received: from righttwix.rockwellcollins.com (righttwix.rockwellcollins.com [192.168.141.218]) by dtulimr01.rockwellcollins.com (Postfix) with ESMTP id D2808607CC; Thu, 7 Feb 2019 15:50:48 -0600 (CST) From: Brandon Maier To: jdelvare@suse.com, linux@roeck-us.net Cc: linux-hwmon@vger.kernel.org, Brandon Maier Subject: [PATCH] hwmon: (ad7418) Catch I2C errors Date: Thu, 7 Feb 2019 15:50:36 -0600 Message-Id: <20190207215036.185561-1-brandon.maier@rockwellcollins.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If there is an i2c failure, the ad7416 reports its temperature as 0C. Return an error code so users can properly detect errors. Signed-off-by: Brandon Maier --- Tested on an ad7416, attempting to `cat` the temp1_input while the sensor is physically disconnected returns this: > cat: read error: Remote I/O error --- drivers/hwmon/ad7418.c | 65 +++++++++++++++++++++++++++++++----------- 1 file changed, 49 insertions(+), 16 deletions(-) diff --git a/drivers/hwmon/ad7418.c b/drivers/hwmon/ad7418.c index 76f0a5c01e8a..28a91d14d7af 100644 --- a/drivers/hwmon/ad7418.c +++ b/drivers/hwmon/ad7418.c @@ -54,10 +54,11 @@ struct ad7418_data { u16 in[4]; }; -static struct ad7418_data *ad7418_update_device(struct device *dev) +static int ad7418_update_device(struct device *dev) { struct ad7418_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; + s32 val; mutex_lock(&data->lock); @@ -67,47 +68,74 @@ static struct ad7418_data *ad7418_update_device(struct device *dev) int i, ch; /* read config register and clear channel bits */ - cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF); + val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF); + if (val < 0) + goto abort; + + cfg = val; cfg &= 0x1F; - i2c_smbus_write_byte_data(client, AD7418_REG_CONF, + val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF, cfg | AD7418_CH_TEMP); + if (val < 0) + goto abort; + udelay(30); for (i = 0; i < 3; i++) { - data->temp[i] = - i2c_smbus_read_word_swapped(client, - AD7418_REG_TEMP[i]); + val = i2c_smbus_read_word_swapped(client, + AD7418_REG_TEMP[i]); + if (val < 0) + goto abort; + + data->temp[i] = val; } for (i = 0, ch = 4; i < data->adc_max; i++, ch--) { - i2c_smbus_write_byte_data(client, - AD7418_REG_CONF, - cfg | AD7418_REG_ADC_CH(ch)); + val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF, + cfg | AD7418_REG_ADC_CH(ch)); + if (val < 0) + goto abort; udelay(15); - data->in[data->adc_max - 1 - i] = - i2c_smbus_read_word_swapped(client, - AD7418_REG_ADC); + val = i2c_smbus_read_word_swapped(client, + AD7418_REG_ADC); + if (val < 0) + goto abort; + + data->in[data->adc_max - 1 - i] = val; } /* restore old configuration value */ - i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg); + val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, + cfg); + if (val < 0) + goto abort; data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->lock); + return 0; - return data; +abort: + data->valid = 0; + mutex_unlock(&data->lock); + return val; } static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); - struct ad7418_data *data = ad7418_update_device(dev); + struct ad7418_data *data = dev_get_drvdata(dev); + int ret; + + ret = ad7418_update_device(dev); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->temp[attr->index])); } @@ -116,7 +144,12 @@ static ssize_t adc_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); - struct ad7418_data *data = ad7418_update_device(dev); + struct ad7418_data *data = dev_get_drvdata(dev); + int ret; + + ret = ad7418_update_device(dev); + if (ret < 0) + return ret; return sprintf(buf, "%d\n", ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);