[PATCH v8 1/2] Driver for TI HDC20x0 humidity and temperature sensors

Eugene Zalkonnikov
2020-05-18T19:15:35Z

HDC2010/2080 driver and sysfs documentation for its heater element.

Signed-off-by: Eugene Zaikonnikov <eugene.zaikonnikov@norphonic.com>

diff -uprN -X linux-5.3.8/Documentation/dontdiff linux-5.3.8/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010 linux-5.3.8_hdc2010/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010
--- linux-5.3.8/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010 1970-01-01 01:00:00.000000000 +0100
+++ linux-5.3.8_hdc2010/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010 2019-12-02 11:09:25.803326999 +0100
@@ -0,0 +1,9 @@
+What: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw
+What: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw_available
+KernelVersion: 5.3.8
+Contact: linux-iio@vger.kernel.org
+Description:
+ Controls the heater device within the humidity sensor to get
+ rid of excess condensation.
+
+ Valid control values are 0 = OFF, and 1 = ON.
diff -uprN -X linux-5.3.8/Documentation/dontdiff linux-5.3.8/drivers/iio/humidity/hdc2010.c linux-5.3.8_hdc2010/drivers/iio/humidity/hdc2010.c
--- linux-5.3.8/drivers/iio/humidity/hdc2010.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-5.3.8_hdc2010/drivers/iio/humidity/hdc2010.c 2020-05-15 17:26:27.121390638 +0200
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * hdc2010.c - Support for the TI HDC2010 and HDC2080
+ * temperature + relative humidity sensors
+ *
+ * Copyright (C) 2020 Norphonic AS
+ * Author: Eugene Zaikonnikov <eugene.zaikonnikov@norphonic.com>
+ *
+ * Datasheets:
+ * http://www.ti.com/product/HDC2010/datasheet
+ * http://www.ti.com/product/HDC2080/datasheet
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define HDC2010_REG_TEMP_LOW 0x00
+#define HDC2010_REG_TEMP_HIGH 0x01
+#define HDC2010_REG_HUMIDITY_LOW 0x02
+#define HDC2010_REG_HUMIDITY_HIGH 0x03
+#define HDC2010_REG_INTERRUPT_DRDY 0x04
+#define HDC2010_REG_TEMP_MAX 0x05
+#define HDC2010_REG_HUMIDITY_MAX 0x06
+#define HDC2010_REG_INTERRUPT_EN 0x07
+#define HDC2010_REG_TEMP_OFFSET_ADJ 0x08
+#define HDC2010_REG_HUMIDITY_OFFSET_ADJ 0x09
+#define HDC2010_REG_TEMP_THR_L 0x0a
+#define HDC2010_REG_TEMP_THR_H 0x0b
+#define HDC2010_REG_RH_THR_L 0x0c
+#define HDC2010_REG_RH_THR_H 0x0d
+#define HDC2010_REG_RESET_DRDY_INT_CONF 0x0e
+#define HDC2010_REG_MEASUREMENT_CONF 0x0f
+
+#define HDC2010_MEAS_CONF GENMASK(2, 1)
+#define HDC2010_MEAS_TRIG BIT(0)
+#define HDC2010_HEATER_EN BIT(3)
+#define HDC2010_AMM GENMASK(6, 4)
+
+struct hdc2010_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ u8 measurement_config;
+ u8 interrupt_config;
+ u8 drdy_config;
+};
+
+enum hdc2010_addr_groups {
+ HDC2010_GROUP_TEMP = 0,
+ HDC2010_GROUP_HUMIDITY
+};
+
+struct hdc2010_reg_record {
+ unsigned long primary;
+ unsigned long peak;
+};
+
+static const struct hdc2010_reg_record hdc2010_reg_translation[] = {
+ [HDC2010_GROUP_TEMP] = {
+ .primary = HDC2010_REG_TEMP_LOW,
+ .peak = HDC2010_REG_TEMP_MAX,
+ },
+ [HDC2010_GROUP_HUMIDITY] = {
+ .primary = HDC2010_REG_HUMIDITY_LOW,
+ .peak = HDC2010_REG_HUMIDITY_MAX,
+ },
+};
+
+static IIO_CONST_ATTR(out_current_heater_raw_available,
+ "0 1");
+
+static struct attribute *hdc2010_attributes[] = {
+ &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group hdc2010_attribute_group = {
+ .attrs = hdc2010_attributes,
+};
+
+static const struct iio_chan_spec hdc2010_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .address = HDC2010_GROUP_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_PEAK) |
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .address = HDC2010_GROUP_HUMIDITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_PEAK) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ },
+ {
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .extend_name = "heater",
+ .output = 1,
+ },
+};
+
+static int hdc2010_update_drdy_config(struct hdc2010_data *data,
+ char mask, char val)
+{
+ u8 tmp = (~mask & data->drdy_config) | val;
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ HDC2010_REG_RESET_DRDY_INT_CONF, tmp);
+ if (!ret)
+ data->drdy_config = tmp;
+
+ return ret;
+}
+
+static int hdc2010_get_prim_measurement_word(struct hdc2010_data *data,
+ struct iio_chan_spec const *chan)
+{
+ struct i2c_client *client = data->client;
+ s32 ret;
+
+ ret = i2c_smbus_read_word_data(client,
+ hdc2010_reg_translation[chan->address].primary);
+
+ if (ret < 0)
+ dev_err(&client->dev, "Could not read sensor measurement word\n");
+
+ return ret;
+}
+
+static int hdc2010_get_peak_measurement_byte(struct hdc2010_data *data,
+ struct iio_chan_spec const *chan)
+{
+ struct i2c_client *client = data->client;
+ s32 ret;
+
+ ret = i2c_smbus_read_byte_data(client,
+ hdc2010_reg_translation[chan->address].peak);
+
+ if (ret < 0)
+ dev_err(&client->dev, "Could not read sensor measurement byte\n");
+
+ return ret;
+}
+
+static int hdc2010_get_heater_status(struct hdc2010_data *data)
+{
+ return !!(data->drdy_config & HDC2010_HEATER_EN);
+}
+
+static int hdc2010_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct hdc2010_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: {
+ int ret;
+
+ if (chan->type == IIO_CURRENT) {
+ *val = hdc2010_get_heater_status(data);
+ return IIO_VAL_INT;
+ }
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ mutex_lock(&data->lock);
+ ret = hdc2010_get_prim_measurement_word(data, chan);
+ mutex_unlock(&data->lock);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_PEAK: {
+ int ret;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ mutex_lock(&data->lock);
+ ret = hdc2010_get_peak_measurement_byte(data, chan);
+ mutex_unlock(&data->lock);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+ /* Scaling up the value so we can use same offset as RAW */
+ *val = ret * 256;
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ *val2 = 65536;
+ if (chan->type == IIO_TEMP)
+ *val = 165000;
+ else
+ *val = 100000;
+ return IIO_VAL_FRACTIONAL;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = -15887;
+ *val2 = 515151;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int hdc2010_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct hdc2010_data *data = iio_priv(indio_dev);
+ int new, ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type != IIO_CURRENT || val2 != 0)
+ return -EINVAL;
+
+ switch (val) {
+ case 1:
+ new = HDC2010_HEATER_EN;
+ break;
+ case 0:
+ new = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mutex_lock(&data->lock);
+ ret = hdc2010_update_drdy_config(data, HDC2010_HEATER_EN, new);
+ mutex_unlock(&data->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info hdc2010_info = {
+ .read_raw = hdc2010_read_raw,
+ .write_raw = hdc2010_write_raw,
+ .attrs = &hdc2010_attribute_group,
+};
+
+static int hdc2010_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *indio_dev;
+ struct hdc2010_data *data;
+ u8 tmp;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
+ return -EOPNOTSUPP;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
+ /*
+ * As DEVICE ID register does not differentiate between
+ * HDC2010 and HDC2080, we have the name hardcoded
+ */
+ indio_dev->name = "hdc2010";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &hdc2010_info;
+
+ indio_dev->channels = hdc2010_channels;
+ indio_dev->num_channels = ARRAY_SIZE(hdc2010_channels);
+
+ /* Enable Automatic Measurement Mode at 5Hz */
+ ret = hdc2010_update_drdy_config(data, HDC2010_AMM, HDC2010_AMM);
+ if (ret)
+ return ret;
+
+ /*
+ * We enable both temp and humidity measurement.
+ * However the measurement won't start even in AMM until triggered.
+ */
+ tmp = (u8)(data->measurement_config & ~HDC2010_MEAS_CONF) |
+ HDC2010_MEAS_TRIG;
+
+ ret = i2c_smbus_write_byte_data(client,
+ HDC2010_REG_MEASUREMENT_CONF, tmp);
+ if (ret)
+ return ret;
+ data->measurement_config = tmp;
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int hdc2010_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct hdc2010_data *data = iio_priv(indio_dev);
+
+ /* Disable Automatic Measurement Mode */
+ if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
+ dev_warn(&client->dev, "Unable to restore default AMM\n");
+
+ iio_device_unregister(indio_dev);
+
+ return 0;
+}
+
+static const struct i2c_device_id hdc2010_id[] = {
+ { "hdc2010" },
+ { "hdc2080" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, hdc2010_id);
+
+static const struct of_device_id hdc2010_dt_ids[] = {
+ { .compatible = "ti,hdc2010" },
+ { .compatible = "ti,hdc2080" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, hdc2010_dt_ids);
+
+static struct i2c_driver hdc2010_driver = {
+ .driver = {
+ .name = "hdc2010",
+ .of_match_table = hdc2010_dt_ids,
+ },
+ .probe = hdc2010_probe,
+ .remove = hdc2010_remove,
+ .id_table = hdc2010_id,
+};
+module_i2c_driver(hdc2010_driver);
+
+MODULE_AUTHOR("Eugene Zaikonnikov <eugene.zaikonnikov@norphonic.com>");
+MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");
diff -uprN -X linux-5.3.8/Documentation/dontdiff linux-5.3.8/drivers/iio/humidity/Kconfig linux-5.3.8_hdc2010/drivers/iio/humidity/Kconfig
--- linux-5.3.8/drivers/iio/humidity/Kconfig 2019-10-29 09:22:48.000000000 +0100
+++ linux-5.3.8_hdc2010/drivers/iio/humidity/Kconfig 2019-11-28 14:31:27.794242693 +0100
@@ -38,6 +38,16 @@ config HDC100X
To compile this driver as a module, choose M here: the module
will be called hdc100x.

+config HDC2010
+ tristate "TI HDC2010 relative humidity and temperature sensor"
+ depends on I2C
+ help
+ Say yes here to build support for the Texas Instruments
+ HDC2010 and HDC2080 relative humidity and temperature sensors.
+
+ To compile this driver as a module, choose M here: the module
+ will be called hdc2010.
+
config HID_SENSOR_HUMIDITY
tristate "HID Environmental humidity sensor"
depends on HID_SENSOR_HUB
diff -uprN -X linux-5.3.8/Documentation/dontdiff linux-5.3.8/drivers/iio/humidity/Makefile linux-5.3.8_hdc2010/drivers/iio/humidity/Makefile
--- linux-5.3.8/drivers/iio/humidity/Makefile 2019-10-29 09:22:48.000000000 +0100
+++ linux-5.3.8_hdc2010/drivers/iio/humidity/Makefile 2019-11-28 14:30:40.609892061 +0100
@@ -6,6 +6,7 @@
obj-$(CONFIG_AM2315) += am2315.o
obj-$(CONFIG_DHT11) += dht11.o
obj-$(CONFIG_HDC100X) += hdc100x.o
+obj-$(CONFIG_HDC2010) += hdc2010.o
obj-$(CONFIG_HID_SENSOR_HUMIDITY) += hid-sensor-humidity.o

hts221-y := hts221_core.o \