diff options
Diffstat (limited to 'drivers/iio/humidity/htu21.c')
| -rw-r--r-- | drivers/iio/humidity/htu21.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/iio/humidity/htu21.c b/drivers/iio/humidity/htu21.c new file mode 100644 index 000000000000..d1636a74980e --- /dev/null +++ b/drivers/iio/humidity/htu21.c @@ -0,0 +1,253 @@ +/* + * 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"); |