--- /dev/null
+/*
+ * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
+ *
+ * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.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/delay.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define HDC100X_REG_TEMP 0x00
+#define HDC100X_REG_HUMIDITY 0x01
+
+#define HDC100X_REG_CONFIG 0x02
+#define HDC100X_REG_CONFIG_HEATER_EN BIT(13)
+
+struct hdc100x_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ u16 config;
+
+ /* integration time of the sensor */
+ int adc_int_us[2];
+};
+
+/* integration time in us */
+static const int hdc100x_int_time[][3] = {
+ { 6350, 3650, 0 }, /* IIO_TEMP channel*/
+ { 6500, 3850, 2500 }, /* IIO_HUMIDITYRELATIVE channel */
+};
+
+/* HDC100X_REG_CONFIG shift and mask values */
+static const struct {
+ int shift;
+ int mask;
+} hdc100x_resolution_shift[2] = {
+ { /* IIO_TEMP channel */
+ .shift = 10,
+ .mask = 1
+ },
+ { /* IIO_HUMIDITYRELATIVE channel */
+ .shift = 8,
+ .mask = 2,
+ },
+};
+
+static IIO_CONST_ATTR(temp_integration_time_available,
+ "0.00365 0.00635");
+
+static IIO_CONST_ATTR(humidityrelative_integration_time_available,
+ "0.0025 0.00385 0.0065");
+
+static IIO_CONST_ATTR(out_current_heater_raw_available,
+ "0 1");
+
+static struct attribute *hdc100x_attributes[] = {
+ &iio_const_attr_temp_integration_time_available.dev_attr.attr,
+ &iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
+ &iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
+ NULL
+};
+
+static struct attribute_group hdc100x_attribute_group = {
+ .attrs = hdc100x_attributes,
+};
+
+static const struct iio_chan_spec hdc100x_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .address = HDC100X_REG_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .address = HDC100X_REG_HUMIDITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME)
+ },
+ {
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .extend_name = "heater",
+ .output = 1,
+ },
+};
+
+static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
+{
+ int tmp = (~mask & data->config) | val;
+ int ret;
+
+ ret = i2c_smbus_write_word_swapped(data->client,
+ HDC100X_REG_CONFIG, tmp);
+ if (!ret)
+ data->config = tmp;
+
+ return ret;
+}
+
+static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
+{
+ int shift = hdc100x_resolution_shift[chan].shift;
+ int ret = -EINVAL;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
+ if (val2 && val2 == hdc100x_int_time[chan][i]) {
+ ret = hdc100x_update_config(data,
+ hdc100x_resolution_shift[chan].mask << shift,
+ i << shift);
+ if (!ret)
+ data->adc_int_us[chan] = val2;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int hdc100x_get_measurement(struct hdc100x_data *data,
+ struct iio_chan_spec const *chan)
+{
+ struct i2c_client *client = data->client;
+ int delay = data->adc_int_us[chan->address];
+ int ret;
+ int val;
+
+ /* start measurement */
+ ret = i2c_smbus_write_byte(client, chan->address);
+ if (ret < 0) {
+ dev_err(&client->dev, "cannot start measurement");
+ return ret;
+ }
+
+ /* wait for integration time to pass */
+ usleep_range(delay, delay + 1000);
+
+ /*
+ * i2c_smbus_read_word_data cannot() be used here due to the command
+ * value not being understood and causes NAKs preventing any reading
+ * from being accessed.
+ */
+ ret = i2c_smbus_read_byte(client);
+ if (ret < 0) {
+ dev_err(&client->dev, "cannot read high byte measurement");
+ return ret;
+ }
+ val = ret << 6;
+
+ ret = i2c_smbus_read_byte(client);
+ if (ret < 0) {
+ dev_err(&client->dev, "cannot read low byte measurement");
+ return ret;
+ }
+ val |= ret >> 2;
+
+ return val;
+}
+
+static int hdc100x_get_heater_status(struct hdc100x_data *data)
+{
+ return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
+}
+
+static int hdc100x_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct hdc100x_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: {
+ int ret;
+
+ mutex_lock(&data->lock);
+ if (chan->type == IIO_CURRENT) {
+ *val = hdc100x_get_heater_status(data);
+ ret = IIO_VAL_INT;
+ } else {
+ ret = hdc100x_get_measurement(data, chan);
+ if (ret >= 0) {
+ *val = ret;
+ ret = IIO_VAL_INT;
+ }
+ }
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+ case IIO_CHAN_INFO_INT_TIME:
+ *val = 0;
+ *val2 = data->adc_int_us[chan->address];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->type == IIO_TEMP) {
+ *val = 165;
+ *val2 = 65536 >> 2;
+ return IIO_VAL_FRACTIONAL;
+ } else {
+ *val = 0;
+ *val2 = 10000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ break;
+ case IIO_CHAN_INFO_OFFSET:
+ *val = -40;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int hdc100x_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct hdc100x_data *data = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ if (val != 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = hdc100x_set_it_time(data, chan->address, val2);
+ mutex_unlock(&data->lock);
+ return ret;
+ case IIO_CHAN_INFO_RAW:
+ if (chan->type != IIO_CURRENT || val2 != 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
+ val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
+ mutex_unlock(&data->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info hdc100x_info = {
+ .read_raw = hdc100x_read_raw,
+ .write_raw = hdc100x_write_raw,
+ .attrs = &hdc100x_attribute_group,
+ .driver_module = THIS_MODULE,
+};
+
+static int hdc100x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *indio_dev;
+ struct hdc100x_data *data;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
+ return -ENODEV;
+
+ 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;
+ indio_dev->name = dev_name(&client->dev);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &hdc100x_info;
+
+ indio_dev->channels = hdc100x_channels;
+ indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
+
+ /* be sure we are in a known state */
+ hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
+ hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id hdc100x_id[] = {
+ { "hdc100x", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, hdc100x_id);
+
+static struct i2c_driver hdc100x_driver = {
+ .driver = {
+ .name = "hdc100x",
+ },
+ .probe = hdc100x_probe,
+ .id_table = hdc100x_id,
+};
+module_i2c_driver(hdc100x_driver);
+
+MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
+MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");
projects / deliverable / linux.git / commitdiff
