diff options
Diffstat (limited to 'drivers/hwmon/htu21.c')
| -rw-r--r-- | drivers/hwmon/htu21.c | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/drivers/hwmon/htu21.c b/drivers/hwmon/htu21.c deleted file mode 100644 index 4c3bbb72f82a..000000000000 --- a/drivers/hwmon/htu21.c +++ /dev/null @@ -1,174 +0,0 @@ -/* - * Measurement Specialties HTU21D humidity and temperature sensor driver - * - * Copyright (C) 2013 William Markezana <william.markezana@meas-spec.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/slab.h> -#include <linux/i2c.h> -#include <linux/hwmon.h> -#include <linux/hwmon-sysfs.h> -#include <linux/err.h> -#include <linux/mutex.h> -#include <linux/device.h> -#include <linux/jiffies.h> - -/* HTU21 Commands */ -#define HTU21_T_MEASUREMENT_HM 0xE3 -#define HTU21_RH_MEASUREMENT_HM 0xE5 - -struct htu21 { - struct i2c_client *client; - struct mutex lock; - bool valid; - unsigned long last_update; - int temperature; - int humidity; -}; - -static inline int htu21_temp_ticks_to_millicelsius(int ticks) -{ - ticks &= ~0x0003; /* clear status bits */ - /* - * Formula T = -46.85 + 175.72 * ST / 2^16 from datasheet p14, - * optimized for integer fixed point (3 digits) arithmetic - */ - return ((21965 * ticks) >> 13) - 46850; -} - -static inline int htu21_rh_ticks_to_per_cent_mille(int ticks) -{ - ticks &= ~0x0003; /* clear status bits */ - /* - * Formula RH = -6 + 125 * SRH / 2^16 from datasheet p14, - * optimized for integer fixed point (3 digits) arithmetic - */ - return ((15625 * ticks) >> 13) - 6000; -} - -static int htu21_update_measurements(struct device *dev) -{ - struct htu21 *htu21 = dev_get_drvdata(dev); - struct i2c_client *client = htu21->client; - int ret = 0; - - mutex_lock(&htu21->lock); - - if (time_after(jiffies, htu21->last_update + HZ / 2) || - !htu21->valid) { - ret = i2c_smbus_read_word_swapped(client, - HTU21_T_MEASUREMENT_HM); - if (ret < 0) - goto out; - htu21->temperature = htu21_temp_ticks_to_millicelsius(ret); - ret = i2c_smbus_read_word_swapped(client, - HTU21_RH_MEASUREMENT_HM); - if (ret < 0) - goto out; - htu21->humidity = htu21_rh_ticks_to_per_cent_mille(ret); - htu21->last_update = jiffies; - htu21->valid = true; - } -out: - mutex_unlock(&htu21->lock); - - return ret >= 0 ? 0 : ret; -} - -static ssize_t htu21_show_temperature(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct htu21 *htu21 = dev_get_drvdata(dev); - int ret; - - ret = htu21_update_measurements(dev); - if (ret < 0) - return ret; - return sprintf(buf, "%d\n", htu21->temperature); -} - -static ssize_t htu21_show_humidity(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct htu21 *htu21 = dev_get_drvdata(dev); - int ret; - - ret = htu21_update_measurements(dev); - if (ret < 0) - return ret; - return sprintf(buf, "%d\n", htu21->humidity); -} - -static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, - htu21_show_temperature, NULL, 0); -static SENSOR_DEVICE_ATTR(humidity1_input, S_IRUGO, - htu21_show_humidity, NULL, 0); - -static struct attribute *htu21_attrs[] = { - &sensor_dev_attr_temp1_input.dev_attr.attr, - &sensor_dev_attr_humidity1_input.dev_attr.attr, - NULL -}; - -ATTRIBUTE_GROUPS(htu21); - -static int htu21_probe(struct i2c_client *client, - const struct i2c_device_id *id) -{ - struct device *dev = &client->dev; - struct htu21 *htu21; - struct device *hwmon_dev; - - if (!i2c_check_functionality(client->adapter, - I2C_FUNC_SMBUS_READ_WORD_DATA)) { - dev_err(&client->dev, - "adapter does not support SMBus word transactions\n"); - return -ENODEV; - } - - htu21 = devm_kzalloc(dev, sizeof(*htu21), GFP_KERNEL); - if (!htu21) - return -ENOMEM; - - htu21->client = client; - mutex_init(&htu21->lock); - - hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, - htu21, - htu21_groups); - return PTR_ERR_OR_ZERO(hwmon_dev); -} - -static const struct i2c_device_id htu21_id[] = { - { "htu21", 0 }, - { } -}; -MODULE_DEVICE_TABLE(i2c, htu21_id); - -static struct i2c_driver htu21_driver = { - .class = I2C_CLASS_HWMON, - .driver = { - .name = "htu21", - }, - .probe = htu21_probe, - .id_table = htu21_id, -}; - -module_i2c_driver(htu21_driver); - -MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>"); -MODULE_DESCRIPTION("MEAS HTU21D humidity and temperature sensor driver"); -MODULE_LICENSE("GPL"); |