From patchwork Thu Sep 14 07:59:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Matyas, Daniel" X-Patchwork-Id: 722743 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 65286EBC for ; Thu, 14 Sep 2023 08:00:59 +0000 (UTC) Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D07011BFF; Thu, 14 Sep 2023 01:00:58 -0700 (PDT) Received: from pps.filterd (m0167089.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 38E4tWxB016921; Thu, 14 Sep 2023 04:00:38 -0400 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3t2y8k26p3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 14 Sep 2023 04:00:38 -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 38E80b9t031700 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 14 Sep 2023 04:00:37 -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, 14 Sep 2023 04:00:36 -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, 14 Sep 2023 04:00:36 -0400 Received: from daniel-Precision-5530.ad.analog.com ([10.48.65.230]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 38E7xpmZ002387; Thu, 14 Sep 2023 04:00:29 -0400 From: Daniel Matyas To: CC: Daniel Matyas , Jean Delvare , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet , , , , Subject: [PATCH v3 5/5] hwmon: max31827: Add custom attribute for resolution Date: Thu, 14 Sep 2023 10:59:48 +0300 Message-ID: <20230914075948.208046-5-daniel.matyas@analog.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230914075948.208046-1-daniel.matyas@analog.com> References: <20230914075948.208046-1-daniel.matyas@analog.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-ORIG-GUID: ___YdsXk-hhQKAFAFEskAETF8Ug5okuf X-Proofpoint-GUID: ___YdsXk-hhQKAFAFEskAETF8Ug5okuf X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-14_05,2023-09-13_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 phishscore=0 clxscore=1015 lowpriorityscore=0 bulkscore=0 adultscore=0 mlxlogscore=999 suspectscore=0 priorityscore=1501 impostorscore=0 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2309140069 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). Signed-off-by: Daniel Matyas --- 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 | 128 ++++++++++++++++++++++++++++--- 2 files changed, 141 insertions(+), 16 deletions(-) diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst index a8bbfb85dd02..d86225a31961 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 file 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 1f29a1f5759d..848a0f3fd821 100644 --- a/drivers/hwmon/max31827.c +++ b/drivers/hwmon/max31827.c @@ -43,6 +43,9 @@ #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_LOW 0x0 @@ -54,6 +57,7 @@ #define MAX31827_16_BIT_TO_M_DGR(x) (sign_extend32(x, 15) * 1000 / 16) #define MAX31827_M_DGR_TO_16_BIT(x) (((x) << 4) / 1000) #define MAX31827_DEVICE_ENABLE(x) ((x) ? 0xA : 0x0) +#define MAX31827_FLT_Q enum chips { max31827, max31828, max31829 }; @@ -77,6 +81,27 @@ 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. @@ -84,6 +109,8 @@ struct max31827_state { struct mutex lock; struct regmap *regmap; bool enable; + unsigned int resolution; + unsigned int update_interval; struct i2c_client *client; }; @@ -101,9 +128,9 @@ 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. @@ -214,9 +241,18 @@ 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); @@ -374,10 +410,14 @@ 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; @@ -388,6 +428,74 @@ 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, cfg; + int ret; + + ret = kstrtouint(buf, 10, &val); + if (ret) + return ret; + + /* + * Convert the desired conversion rate into register + * bits. idx is already initialized with 1. + * + * 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 = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &cfg); + if (ret) + return ret; + + cfg = (cfg & ~MAX31827_CONFIGURATION_RESOLUTION_MASK) | + FIELD_PREP(MAX31827_CONFIGURATION_RESOLUTION_MASK, idx); + cfg &= ~(MAX31827_CONFIGURATION_CNV_RATE_MASK | + MAX31827_CONFIGURATION_1SHOT_MASK); + + ret = shutdown_write(st, MAX31827_CONFIGURATION_REG, cfg); + + 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 }, @@ -528,7 +636,7 @@ 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); }