From patchwork Mon Sep 30 20:53:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoni Pokusinski X-Patchwork-Id: 13817076 Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com [209.85.167.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A7A301A257B; Mon, 30 Sep 2024 20:56:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727729768; cv=none; b=R9BGXRP1IZZljJAK7RVKRG5lZI8+WQEXplDI/3vDmbm+4d8Jut94bzFx9A07H3Ikief+E1NOSeOHEzE9pnwUMFGU2IONB8SvJWSXanDZ7q+IYP371yXbuX9EM1FnpykWfEksRXQUQJw4S2dC3sRtfV9X5D2jr7Dev41YvzhOmcc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727729768; c=relaxed/simple; bh=vJJ6WFVW05VD7rStX6CjcBuNTFQ68FwcMOjbfHfMlwE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=EI9u1S9zb8q+Q9Njey6C1ry2TjnnhJ3qxnnxEDOj7xqZRHv1tOPsVenHz9u7gcP84IdYZu9FjF0S3ZuYNlFtid8JLnmSMhlGRETyijVPlbS5IuK9nLLxQCHEWEnkqhtZ5QinMc5QkRQ2LHokujiKRiIr7lDGrWK+LzF1YjKc4GM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bMJoLuWS; arc=none smtp.client-ip=209.85.167.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bMJoLuWS" Received: by mail-lf1-f44.google.com with SMTP id 2adb3069b0e04-53991d05416so2162885e87.2; Mon, 30 Sep 2024 13:56:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1727729765; x=1728334565; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=MRFU83dgnBcJidUfcqf/WUK3UnVXPT6XkU2nln7aUfU=; b=bMJoLuWSTfF1Z6Cul2hxvlZ1CJ3SG19wWR5XGZAutW4w8+eYZDf5LUhbOpJhTHx8qt qMC4JNPvFAQfycTgl5prvDAgIS4rz4R4Ef+dX4NLZdN7KDCs1n1B/WJ1I/MwalKjyO1h oEUo3gN3NRkMHo+pLrIuWYXgLaXZNv6nBRAE+CpvzgZNKnsfGU0WoCyLemDg86GmTKiQ //B55Kk0tY8xVBW4SiuB+6IT8oFcpk5WbwKxzYbkc3S8bsLLeafbYGzm0uXDDNiCMPNy od5sjOVL+XoU8BLEIVWkk1/Yeu2/MT5AXkbpvEXB+kJ8HcJEIpnyJTEw2mXxu0kCSwTJ rl4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727729765; x=1728334565; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=MRFU83dgnBcJidUfcqf/WUK3UnVXPT6XkU2nln7aUfU=; b=Jq2gZgfpDUtbp1z+z+9Lal95uO2T4XGBen5bWcKt5DrPrqUwcVCv/qLELADMItlhyR p65B+IntwGyFDXjE4h8HMTrS6GRGdYJhNXu0EglfDiXS/oTccIMAfECyx4m306lFtWeY TN2suqU/LXW/BHp8uHQka7J7QRFIoAdhCqSsFEB/VfDa+SM4b63TzF79ITV1VZTPGPCv K78sWlGgDE7/pjVN6sN5yM8zYrR6HVOg0EJw3+B6Hh5uTpEh3aYuQ2jC4kUa1J0l0Igg gvyI1dwqSnwFyZsruzVZg1UT0AgLuCwr0JiL28wrkT0DlmAmhcgWw8Hbgpq19mVKhtDH ctTg== X-Forwarded-Encrypted: i=1; AJvYcCX5Tj/eJlC7zaYvQ9ELWED6woMQKVYSsqvQv/7BM/7V6zZej3YwF/yMKohWSdlajCIkslfEC8lU8cvJqA==@vger.kernel.org X-Gm-Message-State: AOJu0Yx6smwi+yoJOz5aUFghFwu4QdUJe0SZuEuVsLOyIrwVx00nuzek L8SX7JgJzCRriCeAPqfwe165GULb5tLJwK9JB4dSd4lXfg0W7KJ6 X-Google-Smtp-Source: AGHT+IH4gflzs+8r498eeRI9nTA6+LmRZhIPe4EXlmL6wVE9bf0lbNV0aKuubFiQYuKTCbVTofVZpA== X-Received: by 2002:a05:6512:3d93:b0:533:4620:ebec with SMTP id 2adb3069b0e04-5389fc343aamr10552822e87.3.1727729764288; Mon, 30 Sep 2024 13:56:04 -0700 (PDT) Received: from localhost.localdomain ([90.156.117.233]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a93c27c5b70sm579191266b.47.2024.09.30.13.56.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Sep 2024 13:56:03 -0700 (PDT) From: Antoni Pokusinski To: linux@roeck-us.net, jdelvare@suse.com Cc: linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, Antoni Pokusinski Subject: [PATCH RESEND v4] hwmon: (sht4x): add heater support Date: Mon, 30 Sep 2024 22:53:47 +0200 Message-Id: <20240930205346.2147-1-apokusinski01@gmail.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-hwmon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add support for manipulating the internal heater of sht4x devices. Enabling the heater removes condensed water from the sensor surface which disturbs the relative humidity measurements. The heater can operate at three heating levels (20, 110 or 200 milliwatts). Also, two heating durations may be selected (0.1 or 1s). Once the heating time elapses the heater is automatically switched off. Changes since v3: * struct sht4x_data: add heating_complete timestamp * struct sht4x_data: add data_pending flag * heater_enable_store: return -EINVAL if input != 1 * heater_enable_store: check for data->heating_complete and update it * heater_enable_store: set data_pending flag after heating request * sht4x_read_values: msleep if heating in progress * sht4x_read_values: dont send measurement request if data_pending * heater_enable attr: make it RW * Documentation: update info about heater_enable attr Changes since v2: * heater_enable_store: remove unnecessary if * Documentation: remove incorrect info about turning off the heater * be more specific in the patch description Changes since v1: * explain the use case of the new attributes set * heater_enable attr: make it write-only * heater_enable_store: define cmd as u8 instead of u8* * heater_enable_store: remove unreachable data path * heater_enable_store: remove unnecessary lock * heater_enable_store: call i2c_master_send only if status==true * define attributes as DEVICE_ATTR_* instead of SENSOR_DEVICE_ATTR_* Signed-off-by: Antoni Pokusinski --- Documentation/hwmon/sht4x.rst | 14 +++ drivers/hwmon/sht4x.c | 184 ++++++++++++++++++++++++++++++++-- 2 files changed, 189 insertions(+), 9 deletions(-) diff --git a/Documentation/hwmon/sht4x.rst b/Documentation/hwmon/sht4x.rst index daf21e763425..ba094ad0e281 100644 --- a/Documentation/hwmon/sht4x.rst +++ b/Documentation/hwmon/sht4x.rst @@ -42,4 +42,18 @@ humidity1_input Measured humidity in %H update_interval The minimum interval for polling the sensor, in milliseconds. Writable. Must be at least 2000. +heater_power The requested heater power, in milliwatts. + Available values: 20, 110, 200 (default: 200). +heater_time The requested operating time of the heater, + in milliseconds. + Available values: 100, 1000 (default 1000). +heater_enable Enable the heater with the selected power + and for the selected time in order to remove + condensed water from the sensor surface. The + heater cannot be manually turned off once + enabled (it will automatically turn off + after completing its operation). + + - 0: turned off (read-only value) + - 1: turn on =============== ============================================ diff --git a/drivers/hwmon/sht4x.c b/drivers/hwmon/sht4x.c index b8916d2735b5..6c9b776237c2 100644 --- a/drivers/hwmon/sht4x.c +++ b/drivers/hwmon/sht4x.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -31,6 +32,12 @@ */ #define SHT4X_CMD_MEASURE_HPM 0b11111101 #define SHT4X_CMD_RESET 0b10010100 +#define SHT4X_CMD_HEATER_20_1 0b00011110 +#define SHT4X_CMD_HEATER_20_01 0b00010101 +#define SHT4X_CMD_HEATER_110_1 0b00101111 +#define SHT4X_CMD_HEATER_110_01 0b00100100 +#define SHT4X_CMD_HEATER_200_1 0b00111001 +#define SHT4X_CMD_HEATER_200_01 0b00110010 #define SHT4X_CMD_LEN 1 #define SHT4X_CRC8_LEN 1 @@ -49,6 +56,10 @@ DECLARE_CRC8_TABLE(sht4x_crc8_table); * struct sht4x_data - All the data required to operate an SHT4X chip * @client: the i2c client associated with the SHT4X * @lock: a mutex that is used to prevent parallel access to the i2c client + * @heating_complete: the time that the last heating finished + * @data_pending: true if and only if there are measurements to retrieve after heating + * @heater_power: the power at which the heater will be started + * @heater_time: the time for which the heater will remain turned on * @valid: validity of fields below * @update_interval: the minimum poll interval * @last_updated: the previous time that the SHT4X was polled @@ -58,6 +69,10 @@ DECLARE_CRC8_TABLE(sht4x_crc8_table); struct sht4x_data { struct i2c_client *client; struct mutex lock; /* atomic read data updates */ + unsigned long heating_complete; /* in jiffies */ + bool data_pending; + u32 heater_power; /* in milli-watts */ + u32 heater_time; /* in milli-seconds */ bool valid; /* validity of fields below */ long update_interval; /* in milli-seconds */ long last_updated; /* in jiffies */ @@ -79,19 +94,30 @@ static int sht4x_read_values(struct sht4x_data *data) u8 crc; u8 cmd[SHT4X_CMD_LEN] = {SHT4X_CMD_MEASURE_HPM}; u8 raw_data[SHT4X_RESPONSE_LENGTH]; + unsigned long curr_jiffies; mutex_lock(&data->lock); - next_update = data->last_updated + - msecs_to_jiffies(data->update_interval); - if (data->valid && time_before_eq(jiffies, next_update)) - goto unlock; + curr_jiffies = jiffies; + if (time_before(curr_jiffies, data->heating_complete)) + msleep(jiffies_to_msecs(data->heating_complete - curr_jiffies)); - ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN); - if (ret < 0) - goto unlock; + if (data->data_pending && + time_before(jiffies, data->heating_complete + data->update_interval)) { + data->data_pending = false; + } else { + next_update = data->last_updated + + msecs_to_jiffies(data->update_interval); - usleep_range(SHT4X_MEAS_DELAY_HPM, SHT4X_MEAS_DELAY_HPM + SHT4X_DELAY_EXTRA); + if (data->valid && time_before_eq(jiffies, next_update)) + goto unlock; + + ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN); + if (ret < 0) + goto unlock; + + usleep_range(SHT4X_MEAS_DELAY_HPM, SHT4X_MEAS_DELAY_HPM + SHT4X_DELAY_EXTRA); + } ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH); if (ret != SHT4X_RESPONSE_LENGTH) { @@ -215,6 +241,143 @@ static int sht4x_hwmon_write(struct device *dev, enum hwmon_sensor_types type, } } +static ssize_t heater_enable_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", time_before(jiffies, data->heating_complete)); +} + +static ssize_t heater_enable_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + bool status; + ssize_t ret; + u8 cmd; + u32 heating_time_bound; + + ret = kstrtobool(buf, &status); + if (ret) + return ret; + if (!status) + return -EINVAL; + + if (data->heater_time == 100) { + if (data->heater_power == 20) + cmd = SHT4X_CMD_HEATER_20_01; + else if (data->heater_power == 110) + cmd = SHT4X_CMD_HEATER_110_01; + else /* data->heater_power == 200 */ + cmd = SHT4X_CMD_HEATER_200_01; + + heating_time_bound = 110; + } else { /* data->heater_time == 1000 */ + if (data->heater_power == 20) + cmd = SHT4X_CMD_HEATER_20_1; + else if (data->heater_power == 110) + cmd = SHT4X_CMD_HEATER_110_1; + else /* data->heater_power == 200 */ + cmd = SHT4X_CMD_HEATER_200_1; + + heating_time_bound = 1100; + } + + mutex_lock(&data->lock); + + if (time_before(jiffies, data->heating_complete)) { + ret = -EBUSY; + goto unlock; + } + + ret = i2c_master_send(data->client, &cmd, SHT4X_CMD_LEN); + if (ret < 0) + goto unlock; + + data->heating_complete = jiffies + msecs_to_jiffies(heating_time_bound); + data->data_pending = true; +unlock: + mutex_unlock(&data->lock); + return ret; +} + +static ssize_t heater_power_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", data->heater_power); +} + +static ssize_t heater_power_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + u32 power; + ssize_t ret; + + ret = kstrtou32(buf, 10, &power); + if (ret) + return ret; + + if (power != 20 && power != 110 && power != 200) + return -EINVAL; + + data->heater_power = power; + + return count; +} + +static ssize_t heater_time_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", data->heater_time); +} + +static ssize_t heater_time_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct sht4x_data *data = dev_get_drvdata(dev); + u32 time; + ssize_t ret; + + ret = kstrtou32(buf, 10, &time); + if (ret) + return ret; + + if (time != 100 && time != 1000) + return -EINVAL; + + data->heater_time = time; + + return count; +} + +static DEVICE_ATTR_RW(heater_enable); +static DEVICE_ATTR_RW(heater_power); +static DEVICE_ATTR_RW(heater_time); + +static struct attribute *sht4x_attrs[] = { + &dev_attr_heater_enable.attr, + &dev_attr_heater_power.attr, + &dev_attr_heater_time.attr, + NULL +}; + +ATTRIBUTE_GROUPS(sht4x); + static const struct hwmon_channel_info * const sht4x_info[] = { HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL), HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), @@ -255,6 +418,9 @@ static int sht4x_probe(struct i2c_client *client) data->update_interval = SHT4X_MIN_POLL_INTERVAL; data->client = client; + data->heater_power = 200; + data->heater_time = 1000; + data->heating_complete = jiffies; mutex_init(&data->lock); @@ -270,7 +436,7 @@ static int sht4x_probe(struct i2c_client *client) client->name, data, &sht4x_chip_info, - NULL); + sht4x_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }