On Sun, Aug 30, 2015 at 2:43 AM, Peter Meerwald <pmeerw@xxxxxxxxxx> wrote:
>
>> 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
Sorry not sure I follow. If ret is 0 it sets IIO_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
