iio: humidity: Add TI HDC20x0 support
authorEugene Zaikonnikov <ez@norphonic.com>
Fri, 7 Aug 2020 14:17:55 +0000 (16:17 +0200)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Thu, 3 Sep 2020 18:40:44 +0000 (19:40 +0100)
Add driver support for HDC2010/2080 series devices and sysfs
documentation for their heater element.

HDC2010 is an integrated high-accuracy humidity and temperature sensor
with very low power consumption. The device includes a resistive heating
element. The temperature range is -40C to 125C with 0.2C
accuracy. Humidity measurement is 0 to 100% with 2% RH accuracy.

Signed-off-by: Eugene Zaikonnikov <ez@norphonic.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010 [new file with mode: 0644]
drivers/iio/humidity/Kconfig
drivers/iio/humidity/Makefile
drivers/iio/humidity/hdc2010.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010 b/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010
new file mode 100644 (file)
index 0000000..5b78af5
--- /dev/null
@@ -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.
index 6c5507a6cd74ef8e0c595adedc2ca2f011dedc71..6549fcf6db698680b321e3bedcf43f7f13ca684f 100644 (file)
@@ -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
index ae4204995017ff687c08a2b91d1523bef062a9cf..f19ff3de97c56743f0ac51e2768e11c7a2816846 100644 (file)
@@ -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 \
diff --git a/drivers/iio/humidity/hdc2010.c b/drivers/iio/humidity/hdc2010.c
new file mode 100644 (file)
index 0000000..744cb0f
--- /dev/null
@@ -0,0 +1,353 @@
+// 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 <ez@norphonic.com>
+ *
+ * Datasheet: https://www.ti.com/product/HDC2010/datasheet
+ * Datasheet: https://www.ti.com/product/HDC2080/datasheet
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/bitops.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)
+               return ret;
+
+       data->drdy_config = tmp;
+
+       return 0;
+}
+
+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 = (data->measurement_config & ~HDC2010_MEAS_CONF) |
+               HDC2010_MEAS_TRIG;
+
+       ret = i2c_smbus_write_byte_data(client, HDC2010_REG_MEASUREMENT_CONF, tmp);
+       if (ret) {
+               dev_warn(&client->dev, "Unable to set up measurement\n");
+               if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
+                       dev_warn(&client->dev, "Unable to restore default AMM\n");
+               return ret;
+       };
+
+       data->measurement_config = tmp;
+
+       return iio_device_register(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);
+
+       iio_device_unregister(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");
+
+       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 <ez@norphonic.com>");
+MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");