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hwmon: add support for Sensirion SHT3x sensors

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This driver implements support for the Sensirion SHT3x-DIS chip,
a humidity and temperature sensor. Temperature is measured
in degrees celsius, relative humidity is expressed as a percentage.
In the sysfs interface, all values are scaled by 1000,
i.e. the value for 31.5 degrees celsius is 31500.

Signed-off-by: Pascal Sachs <pascal.sachs@sensirion.com>
[groeck: Fixed 'Variable length array is used' gcc warning]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
David Frey 2016-06-02 09:59:11 +02:00 committed by Guenter Roeck
parent 76b5808e8c
commit 7c84f7f80d
5 changed files with 834 additions and 0 deletions
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72
Documentation/hwmon/sht3x Normal file
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@ -0,0 +1,72 @@
Kernel driver sht3x
===================
Supported chips:
* Sensirion SHT3x-DIS
Prefix: 'sht3x'
Addresses scanned: none
Datasheet: http://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity/Sensirion_Humidity_Datasheet_SHT3x_DIS.pdf
Author:
David Frey <david.frey@sensirion.com>
Pascal Sachs <pascal.sachs@sensirion.com>
Description
-----------
This driver implements support for the Sensirion SHT3x-DIS chip, a humidity
and temperature sensor. Temperature is measured in degrees celsius, relative
humidity is expressed as a percentage. In the sysfs interface, all values are
scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500.
The device communicates with the I2C protocol. Sensors can have the I2C
addresses 0x44 or 0x45, depending on the wiring. See
Documentation/i2c/instantiating-devices for methods to instantiate the device.
There are two options configurable by means of sht3x_platform_data:
1. blocking (pull the I2C clock line down while performing the measurement) or
non-blocking mode. Blocking mode will guarantee the fastest result but
the I2C bus will be busy during that time. By default, non-blocking mode
is used. Make sure clock-stretching works properly on your device if you
want to use blocking mode.
2. high or low accuracy. High accuracy is used by default and using it is
strongly recommended.
The sht3x sensor supports a single shot mode as well as 5 periodic measure
modes, which can be controlled with the update_interval sysfs interface.
The allowed update_interval in milliseconds are as follows:
* 0 single shot mode
* 2000 0.5 Hz periodic measurement
* 1000 1 Hz periodic measurement
* 500 2 Hz periodic measurement
* 250 4 Hz periodic measurement
* 100 10 Hz periodic measurement
In the periodic measure mode, the sensor automatically triggers a measurement
with the configured update interval on the chip. When a temperature or humidity
reading exceeds the configured limits, the alert attribute is set to 1 and
the alert pin on the sensor is set to high.
When the temperature and humidity readings move back between the hysteresis
values, the alert bit is set to 0 and the alert pin on the sensor is set to
low.
sysfs-Interface
---------------
temp1_input: temperature input
humidity1_input: humidity input
temp1_max: temperature max value
temp1_max_hyst: temperature hysteresis value for max limit
humidity1_max: humidity max value
humidity1_max_hyst: humidity hysteresis value for max limit
temp1_min: temperature min value
temp1_min_hyst: temperature hysteresis value for min limit
humidity1_min: humidity min value
humidity1_min_hyst: humidity hysteresis value for min limit
temp1_alarm: alarm flag is set to 1 if the temperature is outside the
configured limits. Alarm only works in periodic measure mode
humidity1_alarm: alarm flag is set to 1 if the humidity is outside the
configured limits. Alarm only works in periodic measure mode
update_interval: update interval, 0 for single shot, interval in msec
for periodic measurement. If the interval is not supported
by the sensor, the next faster interval is chosen

11
drivers/hwmon/Kconfig
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@ -1265,6 +1265,17 @@ config SENSORS_SHT21
This driver can also be built as a module. If so, the module
will be called sht21.
config SENSORS_SHT3x
tristate "Sensiron humidity and temperature sensors. SHT3x and compat."
depends on I2C
select CRC8
help
If you say yes here you get support for the Sensiron SHT30 and SHT31
humidity and temperature sensors.
This driver can also be built as a module. If so, the module
will be called sht3x.
config SENSORS_SHTC1
tristate "Sensiron humidity and temperature sensors. SHTC1 and compat."
depends on I2C

1
drivers/hwmon/Makefile
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@ -138,6 +138,7 @@ obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o
obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o
obj-$(CONFIG_SENSORS_SHT15) += sht15.o
obj-$(CONFIG_SENSORS_SHT21) += sht21.o
obj-$(CONFIG_SENSORS_SHT3x) += sht3x.o
obj-$(CONFIG_SENSORS_SHTC1) += shtc1.o
obj-$(CONFIG_SENSORS_SIS5595) += sis5595.o
obj-$(CONFIG_SENSORS_SMM665) += smm665.o

725
drivers/hwmon/sht3x.c Normal file
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@ -0,0 +1,725 @@
/* Sensirion SHT3x-DIS humidity and temperature sensor driver.
* The SHT3x comes in many different versions, this driver is for the
* I2C version only.
*
* Copyright (C) 2016 Sensirion AG, Switzerland
* Author: David Frey <david.frey@sensirion.com>
* Author: Pascal Sachs <pascal.sachs@sensirion.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 <asm/page.h>
#include <linux/crc8.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/platform_data/sht3x.h>
/* commands (high precision mode) */
static const unsigned char sht3x_cmd_measure_blocking_hpm[] = { 0x2c, 0x06 };
static const unsigned char sht3x_cmd_measure_nonblocking_hpm[] = { 0x24, 0x00 };
/* commands (low power mode) */
static const unsigned char sht3x_cmd_measure_blocking_lpm[] = { 0x2c, 0x10 };
static const unsigned char sht3x_cmd_measure_nonblocking_lpm[] = { 0x24, 0x16 };
/* commands for periodic mode */
static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 };
static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 };
/* other commands */
static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d };
static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
/* delays for non-blocking i2c commands, both in us */
#define SHT3X_NONBLOCKING_WAIT_TIME_HPM 15000
#define SHT3X_NONBLOCKING_WAIT_TIME_LPM 4000
#define SHT3X_WORD_LEN 2
#define SHT3X_CMD_LENGTH 2
#define SHT3X_CRC8_LEN 1
#define SHT3X_RESPONSE_LENGTH 6
#define SHT3X_CRC8_POLYNOMIAL 0x31
#define SHT3X_CRC8_INIT 0xFF
#define SHT3X_MIN_TEMPERATURE -45000
#define SHT3X_MAX_TEMPERATURE 130000
#define SHT3X_MIN_HUMIDITY 0
#define SHT3X_MAX_HUMIDITY 100000
enum sht3x_chips {
sht3x,
sts3x,
};
enum sht3x_limits {
limit_max = 0,
limit_max_hyst,
limit_min,
limit_min_hyst,
};
DECLARE_CRC8_TABLE(sht3x_crc8_table);
/* periodic measure commands (high precision mode) */
static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = {
/* 0.5 measurements per second */
{0x20, 0x32},
/* 1 measurements per second */
{0x21, 0x30},
/* 2 measurements per second */
{0x22, 0x36},
/* 4 measurements per second */
{0x23, 0x34},
/* 10 measurements per second */
{0x27, 0x37},
};
/* periodic measure commands (low power mode) */
static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = {
/* 0.5 measurements per second */
{0x20, 0x2f},
/* 1 measurements per second */
{0x21, 0x2d},
/* 2 measurements per second */
{0x22, 0x2b},
/* 4 measurements per second */
{0x23, 0x29},
/* 10 measurements per second */
{0x27, 0x2a},
};
struct sht3x_limit_commands {
const char read_command[SHT3X_CMD_LENGTH];
const char write_command[SHT3X_CMD_LENGTH];
};
static const struct sht3x_limit_commands limit_commands[] = {
/* temp1_max, humidity1_max */
[limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} },
/* temp_1_max_hyst, humidity1_max_hyst */
[limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} },
/* temp1_min, humidity1_min */
[limit_min] = { {0xe1, 0x02}, {0x61, 0x00} },
/* temp_1_min_hyst, humidity1_min_hyst */
[limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} },
};
#define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands)
static const u16 mode_to_update_interval[] = {
0,
2000,
1000,
500,
250,
100,
};
struct sht3x_data {
struct i2c_client *client;
struct mutex i2c_lock; /* lock for sending i2c commands */
struct mutex data_lock; /* lock for updating driver data */
u8 mode;
const unsigned char *command;
u32 wait_time; /* in us*/
unsigned long last_update; /* last update in periodic mode*/
struct sht3x_platform_data setup;
/*
* cached values for temperature and humidity and limits
* the limits arrays have the following order:
* max, max_hyst, min, min_hyst
*/
int temperature;
int temperature_limits[SHT3X_NUM_LIMIT_CMD];
u32 humidity;
u32 humidity_limits[SHT3X_NUM_LIMIT_CMD];
};
static u8 get_mode_from_update_interval(u16 value)
{
size_t index;
u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval);
if (value == 0)
return 0;
/* find next faster update interval */
for (index = 1; index < number_of_modes; index++) {
if (mode_to_update_interval[index] <= value)
return index;
}
return number_of_modes - 1;
}
static int sht3x_read_from_command(struct i2c_client *client,
struct sht3x_data *data,
const char *command,
char *buf, int length, u32 wait_time)
{
int ret;
mutex_lock(&data->i2c_lock);
ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
if (ret != SHT3X_CMD_LENGTH) {
ret = ret < 0 ? ret : -EIO;
goto out;
}
if (wait_time)
usleep_range(wait_time, wait_time + 1000);
ret = i2c_master_recv(client, buf, length);
if (ret != length) {
ret = ret < 0 ? ret : -EIO;
goto out;
}
ret = 0;
out:
mutex_unlock(&data->i2c_lock);
return ret;
}
static int sht3x_extract_temperature(u16 raw)
{
/*
* From datasheet:
* T = -45 + 175 * ST / 2^16
* Adapted for integer fixed point (3 digit) arithmetic.
*/
return ((21875 * (int)raw) >> 13) - 45000;
}
static u32 sht3x_extract_humidity(u16 raw)
{
/*
* From datasheet:
* RH = 100 * SRH / 2^16
* Adapted for integer fixed point (3 digit) arithmetic.
*/
return (12500 * (u32)raw) >> 13;
}
static struct sht3x_data *sht3x_update_client(struct device *dev)
{
struct sht3x_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
u16 interval_ms = mode_to_update_interval[data->mode];
unsigned long interval_jiffies = msecs_to_jiffies(interval_ms);
unsigned char buf[SHT3X_RESPONSE_LENGTH];
u16 val;
int ret = 0;
mutex_lock(&data->data_lock);
/*
* Only update cached readings once per update interval in periodic
* mode. In single shot mode the sensor measures values on demand, so
* every time the sysfs interface is called, a measurement is triggered.
* In periodic mode however, the measurement process is handled
* internally by the sensor and reading out sensor values only makes
* sense if a new reading is available.
*/
if (time_after(jiffies, data->last_update + interval_jiffies)) {
ret = sht3x_read_from_command(client, data, data->command, buf,
sizeof(buf), data->wait_time);
if (ret)
goto out;
val = be16_to_cpup((__be16 *)buf);
data->temperature = sht3x_extract_temperature(val);
val = be16_to_cpup((__be16 *)(buf + 3));
data->humidity = sht3x_extract_humidity(val);
data->last_update = jiffies;
}
out:
mutex_unlock(&data->data_lock);
if (ret)
return ERR_PTR(ret);
return data;
}
/* sysfs attributes */
static ssize_t temp1_input_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sht3x_data *data = sht3x_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
return sprintf(buf, "%d\n", data->temperature);
}
static ssize_t humidity1_input_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct sht3x_data *data = sht3x_update_client(dev);
if (IS_ERR(data))
return PTR_ERR(data);
return sprintf(buf, "%u\n", data->humidity);
}
/*
* limits_update must only be called from probe or with data_lock held
*/
static int limits_update(struct sht3x_data *data)
{
int ret;
u8 index;
int temperature;
u32 humidity;
u16 raw;
char buffer[SHT3X_RESPONSE_LENGTH];
const struct sht3x_limit_commands *commands;
struct i2c_client *client = data->client;
for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) {
commands = &limit_commands[index];
ret = sht3x_read_from_command(client, data,
commands->read_command, buffer,
SHT3X_RESPONSE_LENGTH, 0);
if (ret)
return ret;
raw = be16_to_cpup((__be16 *)buffer);
temperature = sht3x_extract_temperature((raw & 0x01ff) << 7);
humidity = sht3x_extract_humidity(raw & 0xfe00);
data->temperature_limits[index] = temperature;
data->humidity_limits[index] = humidity;
}
return ret;
}
static ssize_t temp1_limit_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sht3x_data *data = dev_get_drvdata(dev);
u8 index = to_sensor_dev_attr(attr)->index;
int temperature_limit = data->temperature_limits[index];
return scnprintf(buf, PAGE_SIZE, "%d\n", temperature_limit);
}
static ssize_t humidity1_limit_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sht3x_data *data = dev_get_drvdata(dev);
u8 index = to_sensor_dev_attr(attr)->index;
u32 humidity_limit = data->humidity_limits[index];
return scnprintf(buf, PAGE_SIZE, "%u\n", humidity_limit);
}
/*
* limit_store must only be called with data_lock held
*/
static size_t limit_store(struct device *dev,
size_t count,
u8 index,
int temperature,
u32 humidity)
{
char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
char *position = buffer;
int ret;
u16 raw;
struct sht3x_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
const struct sht3x_limit_commands *commands;
commands = &limit_commands[index];
memcpy(position, commands->write_command, SHT3X_CMD_LENGTH);
position += SHT3X_CMD_LENGTH;
/*
* ST = (T + 45) / 175 * 2^16
* SRH = RH / 100 * 2^16
* adapted for fixed point arithmetic and packed the same as
* in limit_show()
*/
raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
raw |= ((humidity * 42950) >> 16) & 0xfe00;
*((__be16 *)position) = cpu_to_be16(raw);
position += SHT3X_WORD_LEN;
*position = crc8(sht3x_crc8_table,
position - SHT3X_WORD_LEN,
SHT3X_WORD_LEN,
SHT3X_CRC8_INIT);
mutex_lock(&data->i2c_lock);
ret = i2c_master_send(client, buffer, sizeof(buffer));
mutex_unlock(&data->i2c_lock);
if (ret != sizeof(buffer))
return ret < 0 ? ret : -EIO;
data->temperature_limits[index] = temperature;
data->humidity_limits[index] = humidity;
return count;
}
static ssize_t temp1_limit_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
int temperature;
int ret;
struct sht3x_data *data = dev_get_drvdata(dev);
u8 index = to_sensor_dev_attr(attr)->index;
ret = kstrtoint(buf, 0, &temperature);
if (ret)
return ret;
temperature = clamp_val(temperature, SHT3X_MIN_TEMPERATURE,
SHT3X_MAX_TEMPERATURE);
mutex_lock(&data->data_lock);
ret = limit_store(dev, count, index, temperature,
data->humidity_limits[index]);
mutex_unlock(&data->data_lock);
return ret;
}
static ssize_t humidity1_limit_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
u32 humidity;
int ret;
struct sht3x_data *data = dev_get_drvdata(dev);
u8 index = to_sensor_dev_attr(attr)->index;
ret = kstrtou32(buf, 0, &humidity);
if (ret)
return ret;
humidity = clamp_val(humidity, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
mutex_lock(&data->data_lock);
ret = limit_store(dev, count, index, data->temperature_limits[index],
humidity);
mutex_unlock(&data->data_lock);
return ret;
}
static void sht3x_select_command(struct sht3x_data *data)
{
/*
* In blocking mode (clock stretching mode) the I2C bus
* is blocked for other traffic, thus the call to i2c_master_recv()
* will wait until the data is ready. For non blocking mode, we
* have to wait ourselves.
*/
if (data->mode > 0) {
data->command = sht3x_cmd_measure_periodic_mode;
data->wait_time = 0;
} else if (data->setup.blocking_io) {
data->command = data->setup.high_precision ?
sht3x_cmd_measure_blocking_hpm :
sht3x_cmd_measure_blocking_lpm;
data->wait_time = 0;
} else {
if (data->setup.high_precision) {
data->command = sht3x_cmd_measure_nonblocking_hpm;
data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_HPM;
} else {
data->command = sht3x_cmd_measure_nonblocking_lpm;
data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_LPM;
}
}
}
static int status_register_read(struct device *dev,
struct device_attribute *attr,
char *buffer, int length)
{
int ret;
struct sht3x_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg,
buffer, length, 0);
return ret;
}
static ssize_t temp1_alarm_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
int ret;
ret = status_register_read(dev, attr, buffer,
SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
if (ret)
return ret;
return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x04));
}
static ssize_t humidity1_alarm_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
int ret;
ret = status_register_read(dev, attr, buffer,
SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
if (ret)
return ret;
return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x08));
}
static ssize_t update_interval_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct sht3x_data *data = dev_get_drvdata(dev);
return scnprintf(buf, PAGE_SIZE, "%u\n",
mode_to_update_interval[data->mode]);
}
static ssize_t update_interval_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
u16 update_interval;
u8 mode;
int ret;
const char *command;
struct sht3x_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
ret = kstrtou16(buf, 0, &update_interval);
if (ret)
return ret;
mode = get_mode_from_update_interval(update_interval);
mutex_lock(&data->data_lock);
/* mode did not change */
if (mode == data->mode) {
mutex_unlock(&data->data_lock);
return count;
}
mutex_lock(&data->i2c_lock);
/*
* Abort periodic measure mode.
* To do any changes to the configuration while in periodic mode, we
* have to send a break command to the sensor, which then falls back
* to single shot (mode = 0).
*/
if (data->mode > 0) {
ret = i2c_master_send(client, sht3x_cmd_break,
SHT3X_CMD_LENGTH);
if (ret != SHT3X_CMD_LENGTH)
goto out;
data->mode = 0;
}
if (mode > 0) {
if (data->setup.high_precision)
command = periodic_measure_commands_hpm[mode - 1];
else
command = periodic_measure_commands_lpm[mode - 1];
/* select mode */
ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
if (ret != SHT3X_CMD_LENGTH)
goto out;
}
/* select mode and command */
data->mode = mode;
sht3x_select_command(data);
out:
mutex_unlock(&data->i2c_lock);
mutex_unlock(&data->data_lock);
if (ret != SHT3X_CMD_LENGTH)
return ret < 0 ? ret : -EIO;
return count;
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, temp1_input_show, NULL, 0);
static SENSOR_DEVICE_ATTR(humidity1_input, S_IRUGO, humidity1_input_show,
NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
temp1_limit_show, temp1_limit_store,
limit_max);
static SENSOR_DEVICE_ATTR(humidity1_max, S_IRUGO | S_IWUSR,
humidity1_limit_show, humidity1_limit_store,
limit_max);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
temp1_limit_show, temp1_limit_store,
limit_max_hyst);
static SENSOR_DEVICE_ATTR(humidity1_max_hyst, S_IRUGO | S_IWUSR,
humidity1_limit_show, humidity1_limit_store,
limit_max_hyst);
static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
temp1_limit_show, temp1_limit_store,
limit_min);
static SENSOR_DEVICE_ATTR(humidity1_min, S_IRUGO | S_IWUSR,
humidity1_limit_show, humidity1_limit_store,
limit_min);
static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO | S_IWUSR,
temp1_limit_show, temp1_limit_store,
limit_min_hyst);
static SENSOR_DEVICE_ATTR(humidity1_min_hyst, S_IRUGO | S_IWUSR,
humidity1_limit_show, humidity1_limit_store,
limit_min_hyst);
static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, temp1_alarm_show, NULL, 0);
static SENSOR_DEVICE_ATTR(humidity1_alarm, S_IRUGO, humidity1_alarm_show,
NULL, 0);
static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
update_interval_show, update_interval_store, 0);
static struct attribute *sht3x_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_humidity1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
&sensor_dev_attr_humidity1_max.dev_attr.attr,
&sensor_dev_attr_humidity1_max_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
&sensor_dev_attr_humidity1_min.dev_attr.attr,
&sensor_dev_attr_humidity1_min_hyst.dev_attr.attr,
&sensor_dev_attr_temp1_alarm.dev_attr.attr,
&sensor_dev_attr_humidity1_alarm.dev_attr.attr,
&sensor_dev_attr_update_interval.dev_attr.attr,
NULL
};
static struct attribute *sts3x_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(sht3x);
ATTRIBUTE_GROUPS(sts3x);
static int sht3x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct sht3x_data *data;
struct device *hwmon_dev;
struct i2c_adapter *adap = client->adapter;
struct device *dev = &client->dev;
const struct attribute_group **attribute_groups;
/*
* we require full i2c support since the sht3x uses multi-byte read and
* writes as well as multi-byte commands which are not supported by
* the smbus protocol
*/
if (!i2c_check_functionality(adap, I2C_FUNC_I2C))
return -ENODEV;
ret = i2c_master_send(client, sht3x_cmd_clear_status_reg,
SHT3X_CMD_LENGTH);
if (ret != SHT3X_CMD_LENGTH)
return ret < 0 ? ret : -ENODEV;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->setup.blocking_io = false;
data->setup.high_precision = true;
data->mode = 0;
data->last_update = 0;
data->client = client;
crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL);
if (client->dev.platform_data)
data->setup = *(struct sht3x_platform_data *)dev->platform_data;
sht3x_select_command(data);
mutex_init(&data->i2c_lock);
mutex_init(&data->data_lock);
ret = limits_update(data);
if (ret)
return ret;
if (id->driver_data == sts3x)
attribute_groups = sts3x_groups;
else
attribute_groups = sht3x_groups;
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name,
data,
attribute_groups);
if (IS_ERR(hwmon_dev))
dev_dbg(dev, "unable to register hwmon device\n");
return PTR_ERR_OR_ZERO(hwmon_dev);
}
/* device ID table */
static const struct i2c_device_id sht3x_ids[] = {
{"sht3x", sht3x},
{"sts3x", sts3x},
{}
};
MODULE_DEVICE_TABLE(i2c, sht3x_ids);
static struct i2c_driver sht3x_i2c_driver = {
.driver.name = "sht3x",
.probe = sht3x_probe,
.id_table = sht3x_ids,
};
module_i2c_driver(sht3x_i2c_driver);
MODULE_AUTHOR("David Frey <david.frey@sensirion.com>");
MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver");
MODULE_LICENSE("GPL");

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include/linux/platform_data/sht3x.h Normal file
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/*
* Copyright (C) 2016 Sensirion AG, Switzerland
* Author: David Frey <david.frey@sensirion.com>
* Author: Pascal Sachs <pascal.sachs@sensirion.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.
*
*/
#ifndef __SHT3X_H_
#define __SHT3X_H_
struct sht3x_platform_data {
bool blocking_io;
bool high_precision;
};
#endif /* __SHT3X_H_ */