mirror_ubuntu-kernels/drivers/iio/humidity/hdc3020.c
Javier Carrasco e264b086f4 iio: humidity: hdc3020: add reset management
The HDC3020 provides an active low reset signal that must be handled if
connected. Asserting this signal turns the device into Trigger-on Demand
measurement mode, reducing its power consumption when no measurements
are required like in low-power modes.

According to the datasheet, the longest "Reset Ready" is 3 ms, which is
only taken into account if the reset signal is defined.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240303-hdc3020-pm-v3-3-48bc02b5241b@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2024-03-25 20:10:13 +00:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC3022
* temperature + relative humidity sensors
*
* Copyright (C) 2023
*
* Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
*
* Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf
*/
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/cleanup.h>
#include <linux/crc8.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/regulator/consumer.h>
#include <linux/units.h>
#include <asm/unaligned.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#define HDC3020_S_AUTO_10HZ_MOD0 0x2737
#define HDC3020_S_STATUS 0x3041
#define HDC3020_HEATER_DISABLE 0x3066
#define HDC3020_HEATER_ENABLE 0x306D
#define HDC3020_HEATER_CONFIG 0x306E
#define HDC3020_EXIT_AUTO 0x3093
#define HDC3020_S_T_RH_THRESH_LOW 0x6100
#define HDC3020_S_T_RH_THRESH_LOW_CLR 0x610B
#define HDC3020_S_T_RH_THRESH_HIGH_CLR 0x6116
#define HDC3020_S_T_RH_THRESH_HIGH 0x611D
#define HDC3020_R_T_RH_AUTO 0xE000
#define HDC3020_R_T_LOW_AUTO 0xE002
#define HDC3020_R_T_HIGH_AUTO 0xE003
#define HDC3020_R_RH_LOW_AUTO 0xE004
#define HDC3020_R_RH_HIGH_AUTO 0xE005
#define HDC3020_R_T_RH_THRESH_LOW 0xE102
#define HDC3020_R_T_RH_THRESH_LOW_CLR 0xE109
#define HDC3020_R_T_RH_THRESH_HIGH_CLR 0xE114
#define HDC3020_R_T_RH_THRESH_HIGH 0xE11F
#define HDC3020_R_STATUS 0xF32D
#define HDC3020_THRESH_TEMP_MASK GENMASK(8, 0)
#define HDC3020_THRESH_TEMP_TRUNC_SHIFT 7
#define HDC3020_THRESH_HUM_MASK GENMASK(15, 9)
#define HDC3020_THRESH_HUM_TRUNC_SHIFT 9
#define HDC3020_STATUS_T_LOW_ALERT BIT(6)
#define HDC3020_STATUS_T_HIGH_ALERT BIT(7)
#define HDC3020_STATUS_RH_LOW_ALERT BIT(8)
#define HDC3020_STATUS_RH_HIGH_ALERT BIT(9)
#define HDC3020_READ_RETRY_TIMES 10
#define HDC3020_BUSY_DELAY_MS 10
#define HDC3020_CRC8_POLYNOMIAL 0x31
#define HDC3020_MIN_TEMP -40
#define HDC3020_MAX_TEMP 125
struct hdc3020_data {
struct i2c_client *client;
struct gpio_desc *reset_gpio;
struct regulator *vdd_supply;
/*
* Ensure that the sensor configuration (currently only heater is
* supported) will not be changed during the process of reading
* sensor data (this driver will try HDC3020_READ_RETRY_TIMES times
* if the device does not respond).
*/
struct mutex lock;
};
static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF};
static const struct iio_event_spec hdc3020_t_rh_event[] = {
{
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_RISING,
.mask_separate = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_HYSTERESIS),
},
{
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_FALLING,
.mask_separate = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_HYSTERESIS),
},
};
static const struct iio_chan_spec hdc3020_channels[] = {
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET),
.event_spec = hdc3020_t_rh_event,
.num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),
},
{
.type = IIO_HUMIDITYRELATIVE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |
BIT(IIO_CHAN_INFO_TROUGH),
.event_spec = hdc3020_t_rh_event,
.num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),
},
{
/*
* For setting the internal heater, which can be switched on to
* prevent or remove any condensation that may develop when the
* ambient environment approaches its dew point temperature.
*/
.type = IIO_CURRENT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
.output = 1,
},
};
DECLARE_CRC8_TABLE(hdc3020_crc8_table);
static int hdc3020_write_bytes(struct hdc3020_data *data, u8 *buf, u8 len)
{
struct i2c_client *client = data->client;
struct i2c_msg msg;
int ret, cnt;
msg.addr = client->addr;
msg.flags = 0;
msg.buf = buf;
msg.len = len;
/*
* During the measurement process, HDC3020 will not return data.
* So wait for a while and try again
*/
for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret == 1)
return 0;
mdelay(HDC3020_BUSY_DELAY_MS);
}
dev_err(&client->dev, "Could not write sensor command\n");
return -ETIMEDOUT;
}
static
int hdc3020_read_bytes(struct hdc3020_data *data, u16 reg, u8 *buf, int len)
{
u8 reg_buf[2];
int ret, cnt;
struct i2c_client *client = data->client;
struct i2c_msg msg[2] = {
[0] = {
.addr = client->addr,
.flags = 0,
.buf = reg_buf,
.len = 2,
},
[1] = {
.addr = client->addr,
.flags = I2C_M_RD,
.buf = buf,
.len = len,
},
};
put_unaligned_be16(reg, reg_buf);
/*
* During the measurement process, HDC3020 will not return data.
* So wait for a while and try again
*/
for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {
ret = i2c_transfer(client->adapter, msg, 2);
if (ret == 2)
return 0;
mdelay(HDC3020_BUSY_DELAY_MS);
}
dev_err(&client->dev, "Could not read sensor data\n");
return -ETIMEDOUT;
}
static int hdc3020_read_be16(struct hdc3020_data *data, u16 reg)
{
u8 crc, buf[3];
int ret;
ret = hdc3020_read_bytes(data, reg, buf, 3);
if (ret < 0)
return ret;
crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
if (crc != buf[2])
return -EINVAL;
return get_unaligned_be16(buf);
}
static int hdc3020_exec_cmd(struct hdc3020_data *data, u16 reg)
{
u8 reg_buf[2];
put_unaligned_be16(reg, reg_buf);
return hdc3020_write_bytes(data, reg_buf, 2);
}
static int hdc3020_read_measurement(struct hdc3020_data *data,
enum iio_chan_type type, int *val)
{
u8 crc, buf[6];
int ret;
ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);
if (ret < 0)
return ret;
/* CRC check of the temperature measurement */
crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);
if (crc != buf[2])
return -EINVAL;
/* CRC check of the relative humidity measurement */
crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);
if (crc != buf[5])
return -EINVAL;
if (type == IIO_TEMP)
*val = get_unaligned_be16(buf);
else if (type == IIO_HUMIDITYRELATIVE)
*val = get_unaligned_be16(&buf[3]);
else
return -EINVAL;
return 0;
}
static int hdc3020_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct hdc3020_data *data = iio_priv(indio_dev);
int ret;
if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW: {
guard(mutex)(&data->lock);
ret = hdc3020_read_measurement(data, chan->type, val);
if (ret < 0)
return ret;
return IIO_VAL_INT;
}
case IIO_CHAN_INFO_PEAK: {
guard(mutex)(&data->lock);
if (chan->type == IIO_TEMP)
ret = hdc3020_read_be16(data, HDC3020_R_T_HIGH_AUTO);
else
ret = hdc3020_read_be16(data, HDC3020_R_RH_HIGH_AUTO);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
}
case IIO_CHAN_INFO_TROUGH: {
guard(mutex)(&data->lock);
if (chan->type == IIO_TEMP)
ret = hdc3020_read_be16(data, HDC3020_R_T_LOW_AUTO);
else
ret = hdc3020_read_be16(data, HDC3020_R_RH_LOW_AUTO);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
}
case IIO_CHAN_INFO_SCALE:
*val2 = 65536;
if (chan->type == IIO_TEMP)
*val = 175;
else
*val = 100;
return IIO_VAL_FRACTIONAL;
case IIO_CHAN_INFO_OFFSET:
if (chan->type != IIO_TEMP)
return -EINVAL;
*val = -16852;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static int hdc3020_read_available(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
const int **vals,
int *type, int *length, long mask)
{
if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT)
return -EINVAL;
*vals = hdc3020_heater_vals;
*type = IIO_VAL_INT;
return IIO_AVAIL_RANGE;
}
static int hdc3020_update_heater(struct hdc3020_data *data, int val)
{
u8 buf[5];
int ret;
if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2])
return -EINVAL;
if (!val)
hdc3020_exec_cmd(data, HDC3020_HEATER_DISABLE);
put_unaligned_be16(HDC3020_HEATER_CONFIG, buf);
put_unaligned_be16(val & GENMASK(13, 0), &buf[2]);
buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
ret = hdc3020_write_bytes(data, buf, 5);
if (ret < 0)
return ret;
return hdc3020_exec_cmd(data, HDC3020_HEATER_ENABLE);
}
static int hdc3020_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct hdc3020_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (chan->type != IIO_CURRENT)
return -EINVAL;
guard(mutex)(&data->lock);
return hdc3020_update_heater(data, val);
}
return -EINVAL;
}
static int hdc3020_write_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int val, int val2)
{
struct hdc3020_data *data = iio_priv(indio_dev);
u8 buf[5];
u64 tmp;
u16 reg;
int ret;
/* Supported temperature range is from 40 to 125 degree celsius */
if (val < HDC3020_MIN_TEMP || val > HDC3020_MAX_TEMP)
return -EINVAL;
/* Select threshold register */
if (info == IIO_EV_INFO_VALUE) {
if (dir == IIO_EV_DIR_RISING)
reg = HDC3020_S_T_RH_THRESH_HIGH;
else
reg = HDC3020_S_T_RH_THRESH_LOW;
} else {
if (dir == IIO_EV_DIR_RISING)
reg = HDC3020_S_T_RH_THRESH_HIGH_CLR;
else
reg = HDC3020_S_T_RH_THRESH_LOW_CLR;
}
guard(mutex)(&data->lock);
ret = hdc3020_read_be16(data, reg);
if (ret < 0)
return ret;
switch (chan->type) {
case IIO_TEMP:
/*
* Calculate temperature threshold, shift it down to get the
* truncated threshold representation in the 9LSBs while keeping
* the current humidity threshold in the 7 MSBs.
*/
tmp = ((u64)(((val + 45) * MICRO) + val2)) * 65535ULL;
tmp = div_u64(tmp, MICRO * 175);
val = tmp >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;
val = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, val);
val |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, ret) <<
HDC3020_THRESH_HUM_TRUNC_SHIFT);
break;
case IIO_HUMIDITYRELATIVE:
/*
* Calculate humidity threshold, shift it down and up to get the
* truncated threshold representation in the 7MSBs while keeping
* the current temperature threshold in the 9 LSBs.
*/
tmp = ((u64)((val * MICRO) + val2)) * 65535ULL;
tmp = div_u64(tmp, MICRO * 100);
val = tmp >> HDC3020_THRESH_HUM_TRUNC_SHIFT;
val = FIELD_PREP(HDC3020_THRESH_HUM_MASK, val);
val |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
break;
default:
return -EOPNOTSUPP;
}
put_unaligned_be16(reg, buf);
put_unaligned_be16(val, buf + 2);
buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);
return hdc3020_write_bytes(data, buf, 5);
}
static int hdc3020_read_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int *val, int *val2)
{
struct hdc3020_data *data = iio_priv(indio_dev);
u16 reg;
int ret;
/* Select threshold register */
if (info == IIO_EV_INFO_VALUE) {
if (dir == IIO_EV_DIR_RISING)
reg = HDC3020_R_T_RH_THRESH_HIGH;
else
reg = HDC3020_R_T_RH_THRESH_LOW;
} else {
if (dir == IIO_EV_DIR_RISING)
reg = HDC3020_R_T_RH_THRESH_HIGH_CLR;
else
reg = HDC3020_R_T_RH_THRESH_LOW_CLR;
}
guard(mutex)(&data->lock);
ret = hdc3020_read_be16(data, reg);
if (ret < 0)
return ret;
switch (chan->type) {
case IIO_TEMP:
/*
* Get the temperature threshold from 9 LSBs, shift them to get
* the truncated temperature threshold representation and
* calculate the threshold according to the formula in the
* datasheet.
*/
*val = FIELD_GET(HDC3020_THRESH_TEMP_MASK, ret);
*val = *val << HDC3020_THRESH_TEMP_TRUNC_SHIFT;
*val = -2949075 + (175 * (*val));
*val2 = 65535;
return IIO_VAL_FRACTIONAL;
case IIO_HUMIDITYRELATIVE:
/*
* Get the humidity threshold from 7 MSBs, shift them to get the
* truncated humidity threshold representation and calculate the
* threshold according to the formula in the datasheet.
*/
*val = FIELD_GET(HDC3020_THRESH_HUM_MASK, ret);
*val = (*val << HDC3020_THRESH_HUM_TRUNC_SHIFT) * 100;
*val2 = 65535;
return IIO_VAL_FRACTIONAL;
default:
return -EOPNOTSUPP;
}
}
static irqreturn_t hdc3020_interrupt_handler(int irq, void *private)
{
struct iio_dev *indio_dev = private;
struct hdc3020_data *data;
s64 time;
int ret;
data = iio_priv(indio_dev);
ret = hdc3020_read_be16(data, HDC3020_R_STATUS);
if (ret < 0)
return IRQ_HANDLED;
if (!(ret & (HDC3020_STATUS_T_HIGH_ALERT | HDC3020_STATUS_T_LOW_ALERT |
HDC3020_STATUS_RH_HIGH_ALERT | HDC3020_STATUS_RH_LOW_ALERT)))
return IRQ_NONE;
time = iio_get_time_ns(indio_dev);
if (ret & HDC3020_STATUS_T_HIGH_ALERT)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
IIO_NO_MOD,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_RISING),
time);
if (ret & HDC3020_STATUS_T_LOW_ALERT)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_TEMP, 0,
IIO_NO_MOD,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_FALLING),
time);
if (ret & HDC3020_STATUS_RH_HIGH_ALERT)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,
IIO_NO_MOD,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_RISING),
time);
if (ret & HDC3020_STATUS_RH_LOW_ALERT)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,
IIO_NO_MOD,
IIO_EV_TYPE_THRESH,
IIO_EV_DIR_FALLING),
time);
return IRQ_HANDLED;
}
static const struct iio_info hdc3020_info = {
.read_raw = hdc3020_read_raw,
.write_raw = hdc3020_write_raw,
.read_avail = hdc3020_read_available,
.read_event_value = hdc3020_read_thresh,
.write_event_value = hdc3020_write_thresh,
};
static int hdc3020_power_off(struct hdc3020_data *data)
{
hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO);
if (data->reset_gpio)
gpiod_set_value_cansleep(data->reset_gpio, 1);
return regulator_disable(data->vdd_supply);
}
static int hdc3020_power_on(struct hdc3020_data *data)
{
int ret;
ret = regulator_enable(data->vdd_supply);
if (ret)
return ret;
fsleep(5000);
if (data->reset_gpio) {
gpiod_set_value_cansleep(data->reset_gpio, 0);
fsleep(3000);
}
if (data->client->irq) {
/*
* The alert output is activated by default upon power up,
* hardware reset, and soft reset. Clear the status register.
*/
ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS);
if (ret) {
hdc3020_power_off(data);
return ret;
}
}
ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);
if (ret)
hdc3020_power_off(data);
return ret;
}
static void hdc3020_exit(void *data)
{
hdc3020_power_off(data);
}
static int hdc3020_probe(struct i2c_client *client)
{
struct iio_dev *indio_dev;
struct hdc3020_data *data;
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -EOPNOTSUPP;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
dev_set_drvdata(&client->dev, indio_dev);
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL);
indio_dev->name = "hdc3020";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &hdc3020_info;
indio_dev->channels = hdc3020_channels;
indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);
data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
if (IS_ERR(data->vdd_supply))
return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
"Unable to get VDD regulator\n");
data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
GPIOD_OUT_HIGH);
if (IS_ERR(data->reset_gpio))
return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio),
"Cannot get reset GPIO\n");
ret = hdc3020_power_on(data);
if (ret)
return dev_err_probe(&client->dev, ret, "Power on failed\n");
ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data);
if (ret)
return ret;
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, hdc3020_interrupt_handler,
IRQF_ONESHOT, "hdc3020",
indio_dev);
if (ret)
return dev_err_probe(&client->dev, ret,
"Failed to request IRQ\n");
}
ret = devm_iio_device_register(&data->client->dev, indio_dev);
if (ret)
return dev_err_probe(&client->dev, ret, "Failed to add device");
return 0;
}
static int hdc3020_suspend(struct device *dev)
{
struct iio_dev *iio_dev = dev_get_drvdata(dev);
struct hdc3020_data *data = iio_priv(iio_dev);
return hdc3020_power_off(data);
}
static int hdc3020_resume(struct device *dev)
{
struct iio_dev *iio_dev = dev_get_drvdata(dev);
struct hdc3020_data *data = iio_priv(iio_dev);
return hdc3020_power_on(data);
}
static DEFINE_SIMPLE_DEV_PM_OPS(hdc3020_pm_ops, hdc3020_suspend, hdc3020_resume);
static const struct i2c_device_id hdc3020_id[] = {
{ "hdc3020" },
{ "hdc3021" },
{ "hdc3022" },
{ }
};
MODULE_DEVICE_TABLE(i2c, hdc3020_id);
static const struct of_device_id hdc3020_dt_ids[] = {
{ .compatible = "ti,hdc3020" },
{ .compatible = "ti,hdc3021" },
{ .compatible = "ti,hdc3022" },
{ }
};
MODULE_DEVICE_TABLE(of, hdc3020_dt_ids);
static struct i2c_driver hdc3020_driver = {
.driver = {
.name = "hdc3020",
.pm = pm_sleep_ptr(&hdc3020_pm_ops),
.of_match_table = hdc3020_dt_ids,
},
.probe = hdc3020_probe,
.id_table = hdc3020_id,
};
module_i2c_driver(hdc3020_driver);
MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>");
MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver");
MODULE_LICENSE("GPL");