Re: [PATCH v4 1/2] Driver for TI HDC20x0 humidity and temperature sensors

Jonathan Cameron
2020-02-02T15:42:10Z

On Thu, 23 Jan 2020 21:15:17 +0000
Eugene Zalkonnikov <ez@norphonic.com> wrote:

> Amended HDC2010/2080 diver and sysfs documentation for its heater element.
>
> Signed-off-by: Eugene Zaikonnikov <eugene.zaikonnikov@norphonic.com>

Hi Eugene,

A few really minor things inline. I'd probably just have tidied them
up but looks like you are going around again for the dt binding so
please tidy these up as well.

Thanks,

Jonathan

>
> 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 2020-01-23 17:39:31.217097788 +0100
> @@ -0,0 +1,332 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * hdc2010.c - Support for the TI HDC2010 and HDC2080
> + * temperature + relative humidity sensors
> + *
> + * Copyright (C) 2019 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,
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(2),

Not a lot of point in having a timestamp given buffered output
isn't supported. So just get rid of the timestamp channel.

> +};
> +
> +static int hdc2010_update_drdy_config(struct hdc2010_data *data,
> + char mask, char val)
> +{
> + char 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_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(data->client,

As below.

> + hdc2010_reg_translation[chan->address].primary);
> +
> + if (ret < 0) {

As below. Not going to raise these again but please ensure no other cases.

> + dev_err(&client->dev, "Could not read sensor data\n");
> + }
> +
> + return ret;
> +}
> +
> +static int hdc2010_get_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(data->client,

Might as well use client rather than data->client;

> + hdc2010_reg_translation[chan->address].peak);
> +
> + if (ret < 0) {
> + dev_err(&client->dev, "Could not read sensor data\n");

nitpick : Kernel style is no {} round a single line.

> + }
> +
> + 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);
> + ret = IIO_VAL_INT;
> + } else {
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
> + mutex_lock(&data->lock);
> + ret = hdc2010_get_measurement_word(data, chan);
> + mutex_unlock(&data->lock);
> + iio_device_release_direct_mode(indio_dev);
> + if (ret >= 0) {
> + *val = ret;
> + ret = IIO_VAL_INT;
> + }
> +
> + }
> + return ret;
> + }
> + 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_measurement_byte(data, chan);
> + mutex_unlock(&data->lock);
> + iio_device_release_direct_mode(indio_dev);
> + if (ret >= 0) {
> + /* Scaling up the value so we can use same offset as RAW */
> + *val = ret * 256;
> + ret = IIO_VAL_INT;
> + }
> +
> + return ret;
> + }
> + 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 = -EINVAL;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + if (chan->type != IIO_CURRENT || val2 != 0)
> + return -EINVAL;
> +
> + if (val == 1)
> + new = HDC2010_HEATER_EN;
> + else if (!val)
> + new = 0;
> + else
> + return -EINVAL;

Switch with explicit 0, 1, other handling might be easier to read.

> +
> + 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;
> + indio_dev->name = dev_name(&client->dev);
> + 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 */
> + hdc2010_update_drdy_config(data, HDC2010_AMM, HDC2010_AMM);
> +
> + /*
> + * We enable both temp and humidity measurement.
> + * However the measurement won't start even in AMM until triggered.
> + */
> + tmp = (u8)(~HDC2010_MEAS_CONF |
> + HDC2010_MEAS_TRIG & data->measurement_config) |
> + HDC2010_MEAS_TRIG;
> +
> + ret = i2c_smbus_write_byte_data(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 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,
> + .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 \
>