/* * htu21.c - Support for Measurement-Specialties * htu21 temperature & humidity sensor * and humidity part of MS8607 sensor * * Copyright (c) 2014 Measurement-Specialties * * Licensed under the GPL-2. * * (7-bit I2C slave address 0x40) * * Datasheet: * http://www.meas-spec.com/downloads/HTU21D.pdf * Datasheet: * http://www.meas-spec.com/downloads/MS8607-02BA01.pdf */ #include <linux/init.h> #include <linux/device.h> #include <linux/kernel.h> #include <linux/stat.h> #include <linux/module.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include "../common/ms_sensors/ms_sensors_i2c.h" #define HTU21_RESET 0xFE enum { HTU21, MS8607 }; static const int htu21_samp_freq[4] = { 20, 40, 70, 120 }; /* String copy of the above const for readability purpose */ static const char htu21_show_samp_freq[] = "20 40 70 120"; static int htu21_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *channel, int *val, int *val2, long mask) { int ret, temperature; unsigned int humidity; struct ms_ht_dev *dev_data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_PROCESSED: switch (channel->type) { case IIO_TEMP: /* in milli °C */ ret = ms_sensors_ht_read_temperature(dev_data, &temperature); if (ret) return ret; *val = temperature; return IIO_VAL_INT; case IIO_HUMIDITYRELATIVE: /* in milli %RH */ ret = ms_sensors_ht_read_humidity(dev_data, &humidity); if (ret) return ret; *val = humidity; return IIO_VAL_INT; default: return -EINVAL; } case IIO_CHAN_INFO_SAMP_FREQ: *val = htu21_samp_freq[dev_data->res_index]; return IIO_VAL_INT; default: return -EINVAL; } } static int htu21_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct ms_ht_dev *dev_data = iio_priv(indio_dev); int i, ret; switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: i = ARRAY_SIZE(htu21_samp_freq); while (i-- > 0) if (val == htu21_samp_freq[i]) break; if (i < 0) return -EINVAL; mutex_lock(&dev_data->lock); dev_data->res_index = i; ret = ms_sensors_write_resolution(dev_data, i); mutex_unlock(&dev_data->lock); return ret; default: return -EINVAL; } } static const struct iio_chan_spec htu21_channels[] = { { .type = IIO_TEMP, .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), }, { .type = IIO_HUMIDITYRELATIVE, .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), } }; /* * Meas Spec recommendation is to not read temperature * on this driver part for MS8607 */ static const struct iio_chan_spec ms8607_channels[] = { { .type = IIO_HUMIDITYRELATIVE, .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), } }; static ssize_t htu21_show_battery_low(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ms_ht_dev *dev_data = iio_priv(indio_dev); return ms_sensors_show_battery_low(dev_data, buf); } static ssize_t htu21_show_heater(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ms_ht_dev *dev_data = iio_priv(indio_dev); return ms_sensors_show_heater(dev_data, buf); } static ssize_t htu21_write_heater(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ms_ht_dev *dev_data = iio_priv(indio_dev); return ms_sensors_write_heater(dev_data, buf, len); } static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq); static IIO_DEVICE_ATTR(battery_low, S_IRUGO, htu21_show_battery_low, NULL, 0); static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR, htu21_show_heater, htu21_write_heater, 0); static struct attribute *htu21_attributes[] = { &iio_const_attr_sampling_frequency_available.dev_attr.attr, &iio_dev_attr_battery_low.dev_attr.attr, &iio_dev_attr_heater_enable.dev_attr.attr, NULL, }; static const struct attribute_group htu21_attribute_group = { .attrs = htu21_attributes, }; static const struct iio_info htu21_info = { .read_raw = htu21_read_raw, .write_raw = htu21_write_raw, .attrs = &htu21_attribute_group, .driver_module = THIS_MODULE, }; static int htu21_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct ms_ht_dev *dev_data; struct iio_dev *indio_dev; int ret; u64 serial_number; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { dev_err(&client->dev, "Adapter does not support some i2c transaction\n"); return -ENODEV; } indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data)); if (!indio_dev) return -ENOMEM; dev_data = iio_priv(indio_dev); dev_data->client = client; dev_data->res_index = 0; mutex_init(&dev_data->lock); indio_dev->info = &htu21_info; indio_dev->name = id->name; indio_dev->dev.parent = &client->dev; indio_dev->modes = INDIO_DIRECT_MODE; if (id->driver_data == MS8607) { indio_dev->channels = ms8607_channels; indio_dev->num_channels = ARRAY_SIZE(ms8607_channels); } else { indio_dev->channels = htu21_channels; indio_dev->num_channels = ARRAY_SIZE(htu21_channels); } i2c_set_clientdata(client, indio_dev); ret = ms_sensors_reset(client, HTU21_RESET, 15000); if (ret) return ret; ret = ms_sensors_read_serial(client, &serial_number); if (ret) return ret; dev_info(&client->dev, "Serial number : %llx", serial_number); return devm_iio_device_register(&client->dev, indio_dev); } static const struct i2c_device_id htu21_id[] = { {"htu21", HTU21}, {"ms8607-humidity", MS8607}, {} }; static struct i2c_driver htu21_driver = { .probe = htu21_probe, .id_table = htu21_id, .driver = { .name = "htu21", }, }; module_i2c_driver(htu21_driver); MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver"); MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>"); MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>"); MODULE_LICENSE("GPL v2");