> Add support for the HDC100x temperature and humidity sensors
> including the resistive heater element.
comments inline below
> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
> ---
> .../ABI/testing/sysfs-bus-iio-humidity-hdc100x | 7 +
> drivers/iio/humidity/Kconfig | 10 +
> drivers/iio/humidity/Makefile | 1 +
> drivers/iio/humidity/hdc100x.c | 304 +++++++++++++++++++++
> 4 files changed, 322 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x
> create mode 100644 drivers/iio/humidity/hdc100x.c
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x b/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x
> new file mode 100644
> index 0000000..7e823a8
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x
> @@ -0,0 +1,7 @@
> +What: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw
> +What: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw_available
> +KernelVersion: 4.2
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Controls the heater device within the humidity sensor to get
> + rid of excess condensation.
the description explains the purpose, but not what shall be actually
written to the file; is it on/off, a current, a temperature?
> diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
> index 688c0d1..01906c8 100644
> --- a/drivers/iio/humidity/Kconfig
> +++ b/drivers/iio/humidity/Kconfig
> @@ -12,6 +12,16 @@ config DHT11
> Other sensors should work as well as long as they speak the
> same protocol.
>
> +config HDC100X
> + tristate "TI HDC100x relative humidity and temperature sensor"
> + depends on I2C
> + help
> + Say yes here to build support for the TI HDC100x series of
> + relative humidity and temperature sensor.
sensors
> +
> + To compile this driver as a module, choose M here: the module
> + will be called hdc100x.
> +
> config SI7005
> tristate "SI7005 relative humidity and temperature sensor"
> depends on I2C
> diff --git a/drivers/iio/humidity/Makefile b/drivers/iio/humidity/Makefile
> index 86e2d26..3e62c0a 100644
> --- a/drivers/iio/humidity/Makefile
> +++ b/drivers/iio/humidity/Makefile
> @@ -3,5 +3,6 @@
> #
>
> obj-$(CONFIG_DHT11) += dht11.o
> +obj-$(CONFIG_HDC100X) += hdc100x.o
> obj-$(CONFIG_SI7005) += si7005.o
> obj-$(CONFIG_SI7020) += si7020.o
> diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
> new file mode 100644
> index 0000000..88b21c8
> --- /dev/null
> +++ b/drivers/iio/humidity/hdc100x.c
> @@ -0,0 +1,304 @@
> +/*
> + * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
> + *
> + * Copyright (C) 2015 Matt Ranostay <mranostay@xxxxxxxxx>
> + *
> + * 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 */
> +#define HDC100X_MAX_INT_TIME_ARRAY_SIZE 3
> +static const int hdc100x_int_time[][HDC100X_MAX_INT_TIME_ARRAY_SIZE] = {
> + { 6350, 3650, 0 }, /* IIO_TEMP channel*/
> + { 6500, 3850, 2500 }, /* IIO_HUMIDITYRELATIVE channel */
> +};
> +
> +static const int hdc100x_resolution_shift[][2] = { {10, 1}, {8, 2} };
maybe a comment what the first and second element mean?
above you have a CONSTANT for the number of elements
(HDC100X_MAX_INT_TIME_ARRAY_SIZE), but not here
> +
> +static IIO_CONST_ATTR(temp_integration_time_available,
> + "0.00365 0.00635");
> +
> +static IIO_CONST_ATTR(humidity_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_humidity_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,
> + .channel = 0,
channel is not needed (no plurality of channels of the same type)
> + .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,
> + .channel = 1,
> + .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)
> +{
> + data->config = (~mask & data->config) | val;
> +
> + return i2c_smbus_write_word_data(data->client, HDC100X_REG_CONFIG,
> + cpu_to_be16(data->config));
use i2c_smbus_write_word_swapped(), drop cpu_to_be16()
strictly, data->config should be updated after having successfully written
to register
> +}
> +
> +static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
> +{
> + const int *int_time = (const int *) &hdc100x_int_time[chan];
> + int shift = hdc100x_resolution_shift[chan][0];
> + int ret = -EINVAL;
> + int i;
> +
> + for (i = 0; i < HDC100X_MAX_INT_TIME_ARRAY_SIZE; i++) {
> + if (val2 && val2 == int_time[i]) {
> + ret = hdc100x_update_config(data,
> + hdc100x_resolution_shift[chan][1] << shift,
> + i << shift);
> + data->adc_int_us[chan] = val2;
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int hdc100x_get_measurement(struct hdc100x_data *data,
> + struct iio_chan_spec const *chan,
> + int *val)
> +{
> + struct i2c_client *client = data->client;
> + int delay = data->adc_int_us[chan->channel];
> + int ret;
> +
> + /* 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);
> +
> + if (ret < 0) {
huh? is there a _read_byte() missing?
could a word transfer be used?
> + dev_err(&client->dev, "cannot read low byte measurement");
> + return ret;
> + }
> + *val = ret >> 2;
> +
> + ret = i2c_smbus_read_byte(client);
> + if (ret < 0) {
> + dev_err(&client->dev, "cannot read high byte measurement");
> + return ret;
> + }
> + *val |= ret << 6;
> +
> + return 0;
> +}
> +
> +static inline int get_heater_status(struct hdc100x_data *data)
no hdc100xx_ prefix
drop inline, let the compiler figure out
> +{
> + 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);
> + int ret = -EINVAL;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + mutex_lock(&data->lock);
> + if (chan->type != IIO_CURRENT) {
> + ret = hdc100x_get_measurement(data, chan, val);
> + if (!ret)
> + ret = IIO_VAL_INT;
ret < 0 would be an error condition, don't overwrite with VAL_INT
> + } else {
> + *val = get_heater_status(data);
> + ret = IIO_VAL_INT;
> + }
> + mutex_unlock(&data->lock);
> + break;
> + case IIO_CHAN_INFO_INT_TIME:
> + mutex_lock(&data->lock);
the lock could probably be dropped
> + *val = 0;
> + *val2 = data->adc_int_us[chan->channel];
> + mutex_unlock(&data->lock);
> + return IIO_VAL_INT_PLUS_MICRO;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_TEMP) {
> + *val = 165;
> + *val2 = 65536 >> 2;
> + ret = IIO_VAL_FRACTIONAL;
> + } else {
> + *val = 0;
> + *val2 = 10000;
> + ret = IIO_VAL_INT_PLUS_MICRO;
> + }
> + break;
> + case IIO_CHAN_INFO_OFFSET:
> + *val = -40;
> + return IIO_VAL_INT;
> + default:
> + break;
> + }
> +
> + return ret;
> +}
> +
> +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->channel, val2);
> + mutex_unlock(&data->lock);
> + break;
> + case IIO_CHAN_INFO_RAW:
> + if (chan->type == IIO_CURRENT) {
> + if (val2 != 0)
> + return -EINVAL;
> +
> + mutex_lock(&data->lock);
> + ret = hdc100x_update_config(data,
> + HDC100X_REG_CONFIG_HEATER_EN,
> + val ? 0 : HDC100X_REG_CONFIG_HEATER_EN);
> +
> + if (!ret)
> + ret = IIO_VAL_INT;
no, drop this; this is _write, not _read
> + mutex_unlock(&data->lock);
> + }
> + /* fall-thru */
just return ret and avoid the fall-thru
> + }
> +
> + return ret;
> +}
> +
> +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))
> + 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, 6350);
probably use hdc100x_int_time[0][0] instead of the redundant value
> + hdc100x_set_it_time(data, 1, 6500);
> +
> + 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@xxxxxxxxx>");
> +MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
> +MODULE_LICENSE("GPL");
>
--
Peter Meerwald
+43-664-2444418 (mobile)
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
