From patchwork Thu Oct 26 14:44:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matyas, Daniel" X-Patchwork-Id: 13437628 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B6CAC25B6B for ; Thu, 26 Oct 2023 14:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345307AbjJZOow (ORCPT ); Thu, 26 Oct 2023 10:44:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345293AbjJZOov (ORCPT ); Thu, 26 Oct 2023 10:44:51 -0400 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 189CD1AB; Thu, 26 Oct 2023 07:44:49 -0700 (PDT) Received: from pps.filterd (m0167088.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 39QCuGQU010512; Thu, 26 Oct 2023 10:44:35 -0400 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3tyepmc5yn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 26 Oct 2023 10:44:35 -0400 (EDT) Received: from ASHBMBX8.ad.analog.com (ASHBMBX8.ad.analog.com [10.64.17.5]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 39QEiXqC009119 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 26 Oct 2023 10:44:33 -0400 Received: from ASHBMBX8.ad.analog.com (10.64.17.5) 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 15.2.986.14; Thu, 26 Oct 2023 10:44:32 -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 15.2.986.14 via Frontend Transport; Thu, 26 Oct 2023 10:44:32 -0400 Received: from daniel-Precision-5530.ad.analog.com ([10.48.65.198]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 39QEiEj0031489; Thu, 26 Oct 2023 10:44:27 -0400 From: Daniel Matyas CC: Daniel Matyas , Jean Delvare , Guenter Roeck , Jonathan Corbet , , , Subject: [PATCH v5 4/4] hwmon: max31827: Add custom attribute for resolution Date: Thu, 26 Oct 2023 17:44:04 +0300 Message-ID: <20231026144405.546822-4-daniel.matyas@analog.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231026144405.546822-1-daniel.matyas@analog.com> References: <20231026144405.546822-1-daniel.matyas@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-GUID: plwGlJe-h5lX11mBPReA6mfoUmJpFmWM X-Proofpoint-ORIG-GUID: plwGlJe-h5lX11mBPReA6mfoUmJpFmWM X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-26_13,2023-10-26_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 spamscore=0 priorityscore=1501 phishscore=0 malwarescore=0 mlxlogscore=999 impostorscore=0 clxscore=1015 mlxscore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2310170000 definitions=main-2310260127 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Added custom channel-specific (temp1) attribute for resolution. The wait time for a conversion in one-shot mode (enable = 0) depends on the resolution. When resolution is 12-bit, the conversion time is 140ms, but the minimum update_interval is 125ms. Handled this problem by waiting an additional 15ms (125ms + 15ms = 140ms). Added 'mask' parameter to the shutdown_write() function. Now it can either write or update bits, depending on the value of mask. This is needed, because for alarms a write is necessary, but for resolution only the resolution bits should be updated. Signed-off-by: Daniel Matyas --- v4 -> v5: No change. v3 -> v4: No change. v2 -> v3: Fixed indentation problems in .rst. v1 -> v2: Changed subject. Separated patch. Removed timeout sysfs attribute and kept only resolution. Added temp1_ prefix to resolution. Changed value of resolution from bits to milli-degrees Celsius. Added appropriate documentation. Documentation/hwmon/max31827.rst | 29 ++++++-- drivers/hwmon/max31827.c | 121 ++++++++++++++++++++++++++++--- 2 files changed, 134 insertions(+), 16 deletions(-) diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst index a8bbfb85dd02..44ab9dc064cb 100644 --- a/Documentation/hwmon/max31827.rst +++ b/Documentation/hwmon/max31827.rst @@ -90,11 +90,28 @@ the data sheet are: Enabling the device when it is already enabled has the side effect of setting the conversion frequency to 1 conv/s. The conversion time varies depending on -the resolution. The conversion time doubles with every bit of increased -resolution. For 10 bit resolution 35ms are needed, while for 12 bit resolution -(default) 140ms. When chip is in shutdown mode and a read operation is -requested, one-shot is triggered, the device waits for 140 (conversion time) ms, -and only after that is the temperature value register read. +the resolution. + +The conversion time doubles with every bit of increased resolution. The +available resolutions are: + +- 8 bit -> 8.75 ms conversion time +- 9 bit -> 17.5 ms conversion time +- 10 bit -> 35 ms conversion time +- 12 bit (default) -> 140 ms conversion time + +There is a temp1_resolution attribute which indicates the unit change in the +input temperature in milli-degrees C. + +- 1000 mC -> 8 bit +- 500 mC -> 9 bit +- 250 mC -> 10 bit +- 62 mC -> 12 bit (default) - actually this is 62.5, but the fil returns 62 + +When chip is in shutdown mode and a read operation is requested, one-shot is +triggered, the device waits for ms, and only after that is +the temperature value register read. Note that the conversion times are rounded +up to the nearest possible integer. The LSB of the temperature values is 0.0625 degrees Celsius, but the values of the temperatures are displayed in milli-degrees. This means, that some data is @@ -117,4 +134,4 @@ corresponding status bits. Notes ----- -PEC and resolution are not implemented. +PEC is not implemented. diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c index 8ba387b51157..c9fa6d4d6194 100644 --- a/drivers/hwmon/max31827.c +++ b/drivers/hwmon/max31827.c @@ -37,6 +37,9 @@ #define MAX31827_CONFIGURATION_U_TEMP_STAT_MASK BIT(14) #define MAX31827_CONFIGURATION_O_TEMP_STAT_MASK BIT(15) +#define MAX31827_8_BIT_CNV_TIME 9 +#define MAX31827_9_BIT_CNV_TIME 18 +#define MAX31827_10_BIT_CNV_TIME 35 #define MAX31827_12_BIT_CNV_TIME 140 #define MAX31827_ALRM_POL_HIGH 0x1 @@ -68,6 +71,27 @@ static const u16 max31827_conversions[] = { [MAX31827_CNV_8_HZ] = 125, }; +enum max31827_resolution { + MAX31827_RES_8_BIT = 0, + MAX31827_RES_9_BIT, + MAX31827_RES_10_BIT, + MAX31827_RES_12_BIT, +}; + +static const u16 max31827_resolutions[] = { + [MAX31827_RES_8_BIT] = 1000, + [MAX31827_RES_9_BIT] = 500, + [MAX31827_RES_10_BIT] = 250, + [MAX31827_RES_12_BIT] = 62, +}; + +static const u16 max31827_conv_times[] = { + [MAX31827_RES_8_BIT] = MAX31827_8_BIT_CNV_TIME, + [MAX31827_RES_9_BIT] = MAX31827_9_BIT_CNV_TIME, + [MAX31827_RES_10_BIT] = MAX31827_10_BIT_CNV_TIME, + [MAX31827_RES_12_BIT] = MAX31827_12_BIT_CNV_TIME, +}; + struct max31827_state { /* * Prevent simultaneous access to the i2c client. @@ -75,6 +99,8 @@ struct max31827_state { struct mutex lock; struct regmap *regmap; bool enable; + unsigned int resolution; + unsigned int update_interval; }; static const struct regmap_config max31827_regmap = { @@ -91,9 +117,9 @@ static int shutdown_write(struct max31827_state *st, unsigned int reg, int ret; /* - * Before the Temperature Threshold Alarm and Alarm Hysteresis Threshold - * register values are changed over I2C, the part must be in shutdown - * mode. + * Before the Temperature Threshold Alarm, Alarm Hysteresis Threshold + * and Resolution bits from Configuration register are changed over I2C, + * the part must be in shutdown mode. * * Mutex is used to ensure, that some other process doesn't change the * configuration register. @@ -211,9 +237,18 @@ static int max31827_read(struct device *dev, enum hwmon_sensor_types type, mutex_unlock(&st->lock); return ret; } - - msleep(MAX31827_12_BIT_CNV_TIME); + msleep(max31827_conv_times[st->resolution]); } + + /* + * For 12-bit resolution the conversion time is 140 ms, + * thus an additional 15 ms is needed to complete the + * conversion: 125 ms + 15 ms = 140 ms + */ + if (max31827_resolutions[st->resolution] == 12 && + st->update_interval == 125) + usleep_range(15000, 20000); + ret = regmap_read(st->regmap, MAX31827_T_REG, &uval); mutex_unlock(&st->lock); @@ -371,10 +406,14 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type, res = FIELD_PREP(MAX31827_CONFIGURATION_CNV_RATE_MASK, res); - return regmap_update_bits(st->regmap, - MAX31827_CONFIGURATION_REG, - MAX31827_CONFIGURATION_CNV_RATE_MASK, - res); + ret = regmap_update_bits(st->regmap, + MAX31827_CONFIGURATION_REG, + MAX31827_CONFIGURATION_CNV_RATE_MASK, + res); + if (ret) + return ret; + + st->update_interval = val; } break; @@ -385,6 +424,68 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type, return -EOPNOTSUPP; } +static ssize_t temp1_resolution_show(struct device *dev, + struct device_attribute *devattr, + char *buf) +{ + struct max31827_state *st = dev_get_drvdata(dev); + unsigned int val; + int ret; + + ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &val); + if (ret) + return ret; + + val = FIELD_GET(MAX31827_CONFIGURATION_RESOLUTION_MASK, val); + + return scnprintf(buf, PAGE_SIZE, "%u\n", max31827_resolutions[val]); +} + +static ssize_t temp1_resolution_store(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max31827_state *st = dev_get_drvdata(dev); + unsigned int idx = 0; + unsigned int val; + int ret; + + ret = kstrtouint(buf, 10, &val); + if (ret) + return ret; + + /* + * Convert the desired resolution into register + * bits. idx is already initialized with 0. + * + * This was inspired by lm73 driver. + */ + while (idx < ARRAY_SIZE(max31827_resolutions) && + val < max31827_resolutions[idx]) + idx++; + + if (idx == ARRAY_SIZE(max31827_resolutions) || + val != max31827_resolutions[idx]) + return -EOPNOTSUPP; + + st->resolution = idx; + + ret = shutdown_write(st, MAX31827_CONFIGURATION_REG, + MAX31827_CONFIGURATION_RESOLUTION_MASK, + FIELD_PREP(MAX31827_CONFIGURATION_RESOLUTION_MASK, + idx)); + + return (ret) ? ret : count; +} + +static DEVICE_ATTR_RW(temp1_resolution); + +static struct attribute *max31827_attrs[] = { + &dev_attr_temp1_resolution.attr, + NULL +}; +ATTRIBUTE_GROUPS(max31827); + static const struct i2c_device_id max31827_i2c_ids[] = { { "max31827", max31827 }, { "max31828", max31828 }, @@ -501,7 +602,7 @@ static int max31827_probe(struct i2c_client *client) hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, st, &max31827_chip_info, - NULL); + max31827_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }